JP6876311B1 - Modulated wave resolver device and rotation angle measurement Interpolation correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem to be solved by a high-precision error correction method of a rotation angle of a modulated wave resolver device and a setting of a high-precision error correction value using a rotation angle measurement control device. A rotation angle detection method according to the present invention is for storing rotation angle correction information for correcting a rotation angle for each predetermined first section of a resolver of a modulated wave resolver device in a first storage element in advance. The preparatory step, the step of generating and outputting the modulated wave generation signal by the signal generator, and the step of generating the modulated wave signal from the modulated wave generation signal by the modulation wave generation circuit and driving the input coil of the modulated wave resolver device. , The process of detecting the rotation angle from the output signal from the output coil of the modulated wave resolver device via the rotation angle detection circuit and outputting the rotation angle detection value, and the second step including the rotation angle detection value from the rotation angle detection value. By determining one section, reading the rotation angle correction information at both ends of the first section stored in the first storage element, and linearly interpolating the rotation angle correction information, the rotation angle correction value of the rotation angle detection value can be obtained. It includes a calculation process. [Selection diagram] Fig. 1

Description

The present invention relates to a rotation angle error correction mechanism and a rotation angle error correction value setting of a modulated wave resolver device.

A conventional winding type resolver is composed of an iron core and a plurality of winding coils, and is an electromagnetic absolute displacement detection sensor that detects a rotation angle and a position detection by an electromagnetic induction phenomenon. This winding type resolver has problems such as a large shape and weight and a high manufacturing cost. On the other hand, it is used in a wide range of fields such as aircraft, electric vehicles, robots, and machine tools because it is composed of only an iron core and a winding coil, has a simple structure, is highly reliable, and has excellent environmental resistance.

Further, as a resolver, a modulated wave resolver device disclosed in Patent Document 1 is known in addition to the winding type. Since the modulated wave resolver can use a high-frequency drive signal as compared with the conventional winding type resolver, the detection sensitivity can be increased, and the number of coil turns can be significantly reduced. Therefore, in the modulated wave resolver device, the input and output coils included in the rotation mechanism are patterned and formed on the printed circuit board. As a result, it has excellent characteristics such as small size, light weight, and low manufacturing cost. Further, Reference 2 discloses a modulated wave resolver device using a high frequency (about 500 kHz) modulated wave.

Patent No. 3047231 Japanese Unexamined Patent Publication No. 2018-31704

Resolvers have been used in aerospace, construction machinery, AI robots, machine tools, etc. used outdoors because of their structural robustness and excellent environmental resistance. On the other hand, there is a problem that the rotation angle detection accuracy is low as compared with an encoder or the like. Therefore, the rotation angle error correction of the resolver aiming at high accuracy is generally performed.

There are structural deviations and manufacturing errors between the SIN series input coil of the resolver mechanism and the coil composed of the internal printed circuit board between the stater that outputs the rotation angle θ from the COS series input coil and the rotor. Structural errors inside these resolvers appear as amplitude and phase inconsistencies in the output signals of the resolver.
As this adjustment, it is necessary to precisely adjust the amplitude and phase adjustment between the SIN series input coil and the COS series input coil on the drive circuit. Since this adjustment operation has been performed manually and by trial and error in the past, there is a limit to high-precision correction, and it takes time and effort. What is needed is a rational and highly accurate means of adjusting amplitude and phase.

Each resolver has a unique rotation angle error for each individual with respect to the number of decompositions of 360 degrees per rotation. The resolver is required to correct the rotation angle error with high accuracy due to the characteristics of the rotation sensor. However, it is not realistic to measure the number of decompositions with a measuring instrument and correct it because it becomes difficult to realize when the number of decompositions increases (for example, 16 bits: 65536 points).
Based on the rotation angle error of a small number of measurement points of about 50 to 100 that can be measured realistically, it is subdivided and refined, and finally extended to the resolution corresponding to the resolution number of the resolver to increase the rotation angle error. It would be ideal if it could be accurately interpolated.
In short, it is an issue to be able to accurately interpolate and correct the rotation angle error of a large number of decompositions with a small number of measurement points.

The rotation angle detection method according to the present invention is a method for detecting a rotation angle by a modulated wave resolver device, and is rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device. In advance, a preparatory step for storing in the first storage element, a modulated wave generation signal output step for generating and outputting a modulated wave generation signal by a signal generator, and a modulated wave signal from a modulated wave generation signal by a modulation wave generation circuit. Is generated and the input coil of the modulated wave resolver device is driven, and the rotation angle is detected from the output signal from the output coil of the modulated wave resolver device via the rotation angle detection circuit to detect the rotation angle. A rotation angle detection step for outputting a value and a first section including the rotation angle detection value are determined from the rotation angle detection value, and the rotation angles at both ends of the first section stored in the first storage element. A rotation angle correction step of reading the correction information and linearly interpolating the rotation angle correction information to calculate the rotation angle correction value of the rotation angle detection value, and the rotation angle detection value based on the rotation angle correction value. It includes a correction rotation angle output step of correcting and outputting the corrected correction rotation angle.

In the rotation angle detection method according to the present invention, the rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device is stored in the first storage element in advance, and the modulated wave resolver device. From the rotation angle detection value output from, the first section including the rotation angle detection value is determined, and the rotation angle correction information at both ends of the first section stored in the first storage element is read out to read the rotation angle correction information. By linearly interpolating, the rotation angle correction value of the rotation angle detection value can be calculated, the rotation angle detection value can be corrected based on the rotation angle correction value, and the corrected rotation angle can be output. Using the rotation angle correction information for correcting the rotation angle for each predetermined first section stored in the first storage element in advance, the rotation angle error of the first section is linearly interpolated to obtain the rotation angle detection value. Since the rotation angle correction value is obtained, the rotation angle can be detected accurately and with high accuracy. Further, the rotation angle correction information stored in the first storage element is the rotation angle correction information for each first section, and the rotation angle error of the first section is further linearly interpolated by using this rotation angle correction information. Since the rotation angle correction value of the rotation angle detection value is obtained, the capacity of the rotation angle correction information stored in the first storage element can be reduced. Further, since the load of the arithmetic unit for calculating the rotation angle correction value of the rotation angle detection value can be reduced, the corrected rotation angle corrected at high speed can be output.

Further, in the rotation angle detection method according to the present invention, at least one of the amplitude voltage adjustment information and the phase adjustment information stored in the second storage element is read out and read out before the rotation angle correction information calculation step. Based on the information, the amplitude voltage adjustment circuit controls the amplitude voltage of the modulation wave signal output from the modulation wave generation circuit, and / or the phase adjuster controls the phase of the modulation wave generation signal output from the signal generator. The amplitude voltage adjustment information and the phase adjustment information stored in the second storage element include the rotation angle error adjustment step for controlling the above, and the error of the rotation angle of the resolver is measured in advance, and the error is minimized. It may be characterized by including the minimum amplitude voltage adjustment information and the minimum phase adjustment information.

In the modulated wave resolver device, the SIN series input coil and the COS series input coil of the resolver mechanical mechanism can be formed, for example, on a printed circuit board. However, there may be structural deviations and manufacturing errors between these coils. Structural errors inside these resolvers appear as amplitude and phase inconsistencies in the output signals of the resolver. In the rotation angle detection method according to the present invention, the rotation angle error based on the amplitude and phase mismatch of the output signal of the resolver due to the internal structure of the resolver is measured, and the amplitude voltage adjustment information for reducing these errors is measured. And the phase adjustment information is stored in the second storage element, and the amplitude voltage adjustment information and the phase adjustment information are read out and the amplitude voltage of the modulation wave signal output from the modulation wave generation circuit is controlled by the amplitude voltage adjustment circuit. And / or a rotation angle error adjusting step that controls the phase of the modulated wave generation signal output from the signal generator by the phase adjuster can be included. The amplitude voltage adjustment information and the phase adjustment information can include the minimum amplitude voltage adjustment information that minimizes the error of the rotation angle of the resolver and the minimum phase adjustment information. As a result, the rotation angle error due to the mismatch of the amplitude and phase of the output signal of the resolver due to the structure inside the resolver can be reduced in advance. As a result, the accuracy of the rotation angle correction information for correcting the rotation angle for each predetermined first section can be improved.

Further, in the rotation angle detection method according to the present invention, the minimum amplitude voltage adjustment information and the minimum phase adjustment information are the rotation angle errors obtained by Fourier analyzing the previously measured rotation angle errors of the resolver. It may be characterized by the amplitude voltage adjustment information and the phase adjustment information that minimize the second-order component of the power spectrum.

The rotation angle error due to the structural deviation and manufacturing error of the coil of the modulated wave resolver device appears as a secondary component of the power spectrum of the rotation angle error. In the rotation angle detection method according to the present invention, the minimum amplitude voltage adjustment information and the minimum phase adjustment information are the second order of the power spectrum of the rotation angle error obtained by Fourier analysis of the error of the rotation angle of the resolver measured in advance. Since it is the amplitude voltage adjustment information that minimizes the order component of the above and the phase adjustment information, it is possible to effectively reduce the rotation angle error caused by the structural deviation and the manufacturing error of the coil of the modulated wave resolver device. Can be done.

Further, in the rotation angle detection method according to the present invention, the preparation step includes a step of measuring the rotation angle error of the resolver and calculating an initial rotation angle error in a second section different from the first section, and the first step. A step of calculating the rotation angle error of the first section obtained by interpolating the rotation angle error of the two sections and generating the rotation angle correction information, and the rotation angle correction information being stored in the first storage element. It may be characterized by including a step of memorizing.

Further, in the rotation angle detection method according to the present invention, the preparation step includes a step of measuring the rotation angle error of the resolver and calculating an initial rotation angle error in a second section different from the first section, and the first step. Fourier obtained by removing the first-order component of the power spectrum of the rotation angle error obtained by Fourier-analyzing the rotation angle error of the first section obtained by interpolating the rotation angle error of two sections. It includes a step of calculating the rotation angle error of the first section by inverse Fourier conversion from the converted data and generating the rotation angle correction information, and a step of storing the rotation angle correction information in the first storage element. It may be characterized by that.

In the rotation angle detection method according to the present invention, the inverse is obtained from the Fourier transform data obtained by removing the first-order component of the power spectrum of the rotation angle error obtained by Fourier analyzing the rotation angle error in the first section. The rotation angle error of the first section is calculated by Fourier transform, and the rotation angle correction information is generated. As a result, only the structural error component inside the resolver device, which removes the error related to the eccentricity and the inclination of the axis when the resolver mechanical mechanism is attached to the rotation axis of the object for detecting the rotation angle, is extracted and the rotation angle correction information is obtained. Can be generated. As a result, rotation angle correction information that does not depend on the mounting method of the resolver mechanical mechanism can be obtained, so that it can be applied to a hollow shaft type resolver device.

Further, the rotation angle detection method according to the present invention is characterized in that the initial rotation angle error is obtained as the difference between the rotation angle of the uncorrected resolver or the corrected correction rotation angle and the measured mechanical rotation angle. May be good. The initial rotation angle error can be obtained as the difference between the rotation angle of the uncorrected resolver or the corrected correction rotation angle and the measured machine rotation angle. In particular, when the initial rotation angle error is obtained as the difference between the corrected corrected rotation angle and the measured mechanical rotation angle, the initial rotation angle error is further reduced as compared with the case where the rotation angle of the uncorrected resolver is used. can do.

Further, the modulated wave resolver device according to the present invention is a modulated wave resolver device for detecting a rotation angle, a signal generator that outputs a modulated wave generation signal, and a rotation angle for correcting the detected rotation angle. From the modulated wave generation signal connected to the signal generator and a controller having a first storage element for storing correction information and a calculation unit including a calculation element for calculating a rotation angle correction value from the rotation angle correction information. It includes a modulated wave generation circuit that generates a modulated wave signal, an input coil that is driven by the modulated wave signal output from the modulated wave generation circuit, and an output coil that outputs a rotation angle signal according to the rotation angle of the resolver. A resolver mechanical mechanism and a rotation angle detection circuit connected to the output coil and outputting a rotation angle detection value from the rotation angle signal can be provided. The rotation angle correction information stored in the first storage element is determined corresponding to the rotation angle of each predetermined first section of the resolver, and the calculation element outputs from the rotation angle detection circuit. The first section including the rotation angle detection value is determined from the rotation angle detection value, and the rotation angle correction information at both ends of the first section stored in the first storage element is read and read out. It may be characterized in that the corrected rotation angle corrected by the rotation angle detection value is calculated by linearly interpolating the rotation angle correction information and output from the output terminal of the controller.

Further, the modulated wave resolver device according to the present invention may further include an amplitude voltage adjusting circuit for controlling the amplitude voltage of the modulated wave signal. Further, the controller outputs a second storage element that stores the amplitude voltage adjustment information and the phase adjustment information, and an amplitude voltage adjustment signal for controlling the amplitude voltage adjustment circuit in response to the amplitude voltage adjustment information. An amplitude adjuster and a phase adjuster that outputs a phase adjustment signal for controlling the phase of the modulated wave generation signal corresponding to the phase adjustment information can be provided. Further, the amplitude voltage adjustment information and the phase adjustment information stored in the second storage element measure the error of the rotation angle of the resolver in advance, and the minimum amplitude voltage adjustment information and the minimum phase that minimize the error. It may be characterized by including adjustment information.

Further, in the modulated wave resolver device according to the present invention, the minimum amplitude voltage adjustment information and the minimum phase adjustment information are the rotation angle errors obtained by Fourier-analyzing the previously measured rotation angle errors of the resolver. It may be characterized by the amplitude voltage adjustment information and the phase adjustment information that minimize the second-order component of the power spectrum.

Further, in the modulated wave resolver device according to the present invention, the rotation angle correction information stored in the first storage element measures the initial rotation angle error in the second section different from the first section in advance, and the first It may be characterized by including the rotation angle error of the first section obtained by interpolating the rotation angle error of the two sections.

Further, in the modulated wave resolver device according to the present invention, the rotation angle correction information stored in the first storage element measures the initial rotation angle error in the second section different from the first section in advance, and the first Fourier obtained by removing the first-order component of the power spectrum of the rotation angle error obtained by Fourier-analyzing the rotation angle error of the first section obtained by interpolating the rotation angle error of the two sections. It may be characterized by including the rotation angle error of the first section obtained by the inverse Fourier transform from the converted data.

Further, the modulated wave resolver device according to the present invention is characterized in that the initial rotation angle error is obtained as the difference between the rotation angle of the uncorrected resolver or the corrected correction rotation angle and the measured mechanical rotation angle. May be good.

In the rotation angle detection method according to the present invention, the rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device is stored in the first storage element in advance, and the modulated wave resolver device. From the rotation angle detection value output from, the first section including the rotation angle detection value is determined, and the rotation angle correction information at both ends of the first section stored in the first storage element is read out to read the rotation angle correction information. By linearly interpolating, the rotation angle correction value of the rotation angle detection value can be calculated, the rotation angle detection value can be corrected based on the rotation angle correction value, and the corrected rotation angle can be output. Using the rotation angle correction information for correcting the rotation angle for each predetermined first section stored in the first storage element in advance, the rotation angle error of the first section is linearly interpolated to detect the rotation angle. Since the error correction of the rotation angle is performed in two stages of obtaining the rotation angle correction value of, the rotation angle can be detected accurately and with high accuracy. Further, the rotation angle correction information stored in the first storage element is the rotation angle correction information for each first section, and the rotation angle error of the first section is further linearly interpolated by using this rotation angle correction information. Since the rotation angle correction value of the rotation angle detection value is obtained, the capacity of the rotation angle correction information stored in the first storage element can be reduced. Further, since the load of the arithmetic unit for calculating the rotation angle correction value of the rotation angle detection value can be reduced, the corrected rotation angle corrected at high speed can be output.

Further, the modulated wave resolver device according to the present invention has a first storage element in which rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device is stored in advance. ing. From the rotation angle detection value output from the modulated wave resolver device, the first section including the rotation angle detection value is determined, and the rotation angle correction information at both ends of the first section stored in the first storage element is read out. By linearly interpolating the rotation angle correction information, the rotation angle correction value of the rotation angle detection value can be calculated, the rotation angle detection value can be corrected based on the rotation angle correction value, and the corrected rotation angle can be output. Using the rotation angle correction information for correcting the rotation angle for each predetermined first section stored in the first storage element in advance, the rotation angle error of the first section is linearly interpolated to obtain the rotation angle detection value. Since the error correction of the rotation angle is performed in two stages such as obtaining the rotation angle correction value, the rotation angle can be detected and output with high accuracy.

FIG. 1 is a diagram showing a configuration of a modulated wave resolver device. FIG. 2 is a diagram showing a configuration of a rotation angle measurement control device. FIG. 3 is a diagram showing a processing procedure of rotation angle amplitude / phase adjustment and error interpolation correction. FIG. 4 is a diagram showing an example of an amplitude voltage adjustment circuit of the SIN series and the COS series. FIG. 5 is a diagram showing the relationship between the rotation angle θ and the rotation angle error Δθ. FIG. 6 is a diagram showing an example of a power spectrum of the rotation angle error. FIG. 7 is a diagram illustrating phase adjustment. FIG. 8 is a diagram showing a rotation angle error due to a phase error of orthogonality. FIG. 9 is a diagram showing a flowchart of amplitude / phase adjustment of the rotation angle. FIG. 10 is a diagram illustrating a process of a rotation angle error correction step. FIG. 11 is a diagram showing a flowchart of rotation angle error interpolation correction (first interpolation correction). FIG. 12 is a diagram illustrating a method of second-order interpolation correction (linear interpolation). FIG. 13 is a diagram for explaining the principle configuration of the modulated wave resolver. FIG. 14 is a diagram for explaining the flow of each signal of the rotation angle detection circuit.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 14.
Before explaining the modulated wave resolver according to the present invention, first, the operating principle of the modulated wave resolver device will be described.

FIG. 13 shows a structural diagram of the principle of the modulated wave resolver. The conventional modulated wave resolver is a modulated wave (carrier wave) having orthogonal SIN and COS signal waves as the envelope, and drives the input coil of the resolver mechanical mechanism, and the output modulated wave that accompanies the rotation angle of the resolver from the output coil. It operates on the simple principle of detecting the phase and measuring the rotation angle or rotation speed.

FIG. 14 shows a diagram for explaining the flow of each signal of the rotation angle detection circuit.
The signal in the process of detecting the rotation phase θ from the output modulation wave output from the output coil of the resolver mechanism mechanism 7 is shown with reference to the reference signal. The modulated wave whose phase is rotated by the rotation angle θ output from the output coil of the resolver mechanical mechanism 7 is amplitude-amplified through the differential amplifier. The signal after differential amplification contains various high-frequency components in addition to the AM modulated wave, so the waveform is considerably distorted. When it is passed through the modulated wave reproduction circuit after this, unnecessary high frequency components are removed, and the original AM modulated wave having a signal wave as an envelope is reproduced.

When phase-locked detection is performed with the basic clock in the detection circuit, the envelope of the signal wave is obtained in conjunction with the polarity inversion synchronized with the half cycle of the reference signal. In the subsequent phase synchronous detection, the AM modulated wave is converted into a sine wave.
It is then filtered to obtain a complete signal wave. The phase detection circuit detects the phase input θ from the zero crossing point with this signal wave. The rotation angle of the resolver can be obtained by counting the phase input θ and inputting it to the controller 1.

FIG. 1 shows the configuration of an embodiment of the modulated wave resolver device 1 to which the present invention is applied.
The modulated wave resolver device 1 is composed of an electronic control board, and controls and controls the modulated wave resolver mechanical mechanism 7.
The modulated wave resolver device 1 is composed of a controller 2 incorporating a flash memory, a modulated wave generation circuit 3 and a modulated wave generation circuit 4, which are drive circuits for driving an input coil, an amplitude voltage adjusting circuit 5, and a rotation angle detection circuit 6. Will be done.

The controller 2 is composed of a DSP or an FPGA.
There are various types of circuits as a drive circuit for driving the input coil of the resolver, but in this example, an embodiment using a signed PWM circuit is shown. The SIN-series signal and modulation wave generation circuit 3 drives the input coil of the resolver mechanism mechanism 7, and the COS-series signal and modulation wave generation circuit 4 drives the other input coil.
A rotation angle signal is output from the output coil as the resolver mechanical mechanism 7 rotates. The rotation angle θ is detected by the rotation angle detection circuit 6 and input to the controller 2. The rotation angle θ at this time corresponds to the detected rotation angle in this embodiment.

A flash memory is incorporated in the controller 2, and a plurality of storage areas can be provided. As will be described in detail later, the flash memory stores interpolation correction information and adjustment information. The adjustment information further includes amplitude information and phase information. Further, the flash memory can function as a first storage element and / or a second storage element in the present embodiment. Interpolation correction information is stored in the first storage element, and adjustment information is stored in the second storage element.
The optimum values of the interpolation correction information and the adjustment information in the flash memory are written in advance through the SPI (Serial Peripheral Interface) bus by using the modulated wave resolver measure 1 and the rotation angle measurement control device 12.

When the power is turned on, the amplitude information is output from the amplitude adjuster to the amplitude voltage adjustment circuit, and in this example, is supplied to the power supply Vc of the modulation wave generation circuit 4 to adjust the COS amplitude. The amplitude voltage adjustment circuit can also adjust the modulation wave generation circuit side on the SIN amplitude side.
Similarly, when the power is turned on, the phase information is supplied from the phase adjuster to the SIN series signal generator in this example to adjust the quadrature phase on the SIN side. The phase adjuster can also adjust the COS series signal generator side.
The modulated wave resolver that operates in these adjusted stages shows the minimum rotation angle error (about ± 0.3 degrees to ± 1 degree) before the rotation angle error correction by the flash memory.

Interpolation correction information is further written from the rotation angle measurement control device 12 to the flash memory in the control roller 2 before execution through SPI. At this time, the flash memory functions as the first storage element in the present embodiment.
In the rotation angle measurement control device 12, the first interpolation correction is performed in order to perform further high-precision correction from the stage after the SIN-COS amplitude and phase adjustment. As will be described in detail later, for example, first, 100 points are extracted between 360 degrees and the rotation angle error is measured. This section corresponds to the second section in the present embodiment. Next, for example, a third-order spline interpolation is performed from the measured rotation angle error data of 100 points, and a subdivided cell, which is correction data further subdivided into sections of 2048 points, is generated from the spline function calculation. .. The section subdivided into 2048 points corresponds to the first section in the present embodiment.

In the execution stage of the controller 2 after the power is turned on, the second interpolation correction, which is a correction with higher accuracy, is performed using the subdivided cells. As will be explained in detail later, as a means of obtaining the correction value of the measurement data, the lower bit correction value of the subdivided cell is obtained by linear interpolation, and the miniaturized cell which is the correction value of the total bit length is obtained from it. Generate. From the correction value, the current rotation angle information 11 of the resolver is obtained. This rotation angle information 11 corresponds to the corrected rotation angle output in this embodiment.

FIG. 2 shows the configuration of the rotation angle measurement control device 12.
The rotation angle measurement control device 12 is an external device for measuring the rotation angle and the rotation angle error according to the usage conditions of the modulated wave resolver device 1 and the resolver mechanical mechanism 7 and assisting the correction of the rotation angle error.

The rotation angle measurement control device 12 has the following three functions.
-Measurement of one rotation of the resolver and the rotation angle between 0 and 360 degrees.
-Precisely control and adjust the amplitude and phase adjustment between the SIN series input coil and the COS series input coil on the drive circuit. The obtained amplitude and phase adjustment data are transferred to the adjustment information of the flash memory of the controller 2.
-The optimum value of high-precision correction is calculated using the high-performance arithmetic unit (PC and GPU attached to it) of the external rotation angle measurement control device, and the optimum value (subdivision cell) of the calculation result is calculated in the flash memory of the controller 2. Transfer to interpolation correction information.

In the present invention, in order to correct the total rotation angle error with high accuracy, the calculation mechanism of the controller 2 and the small-capacity flash memory are utilized, and the high-precision correction of the resolver having a large number of decompositions is effective. It has been realized.
In order to realize high-precision correction of the rotation angle error, it is necessary to set the optimum value carefully selected for the small-capacity flash memory.

As this means, the external rotation angle measurement controller is equipped with a high-performance arithmetic unit (PC and GPU attached to it), and is optimally equipped with an arithmetic algorithm (large amount of arithmetic) that minimizes errors including AI and digital signal processing. The value is calculated, and the optimum value (subdivision cell) of the calculation result is set in the flash memory of the controller 2. In the production process, these series of processes are required to be executed at high speed in a continuous loop, so that a high-performance arithmetic unit is an indispensable condition.

On the other hand, the controller 2 serving as the execution machine (FORWARD) is equipped with the minimum necessary low-function arithmetic mechanism and a small-capacity flash memory, and can be executed with a simple configuration and inexpensive hardware.

The rotation angle measurement control device 12 includes a modulated wave resolver device 1, a resolver mechanical mechanism 7, a stepping motor 8 that rotationally drives the resolver mechanical mechanism 7, an interface control unit 9, and a high-performance arithmetic unit PC 10 that controls the system.
The stepping motor 8 has a function of rotating the rotation shaft of the resolver mechanical mechanism 7 by a predetermined rotation angle, and in order to rotate the rotation shaft with higher accuracy, a higher precision encoder may be additionally equipped on the rotation shaft.

The integrated processing of the rotation angle measurement control device 12 is commanded and controlled from the GUI screen of the PC 10. The PC 10 is connected to the interface control unit 9 via USB.
The interface control unit 9 uses the FPGA as a controller and has the following three roles.
(1) Communicate with the PC 10 through the USB line, execute a command from the PC 10, and transmit the information from the modulated wave resolver device 1 via the SPI to the PC 10.
(2) The rotation of the stepping motor connected to the rotating shaft of the resolver mechanical mechanism 7 is controlled through the stepping motor control circuit by the command of the PC 10.
(3) Information is communicated with the modulated wave resolver device 1 through SPI.
From the controller 2, the rotation angle information of the resolver is received by the interface control unit 9 via the SPI, and from the interface control unit 9, the adjustment information and the interpolation correction information, which will be described in detail later, are transmitted to the controller via the SPI. Send to the flash memory of 2.

To measure N points of rotation angle measurement data of 360 degrees per rotation of the resolver, execute the following procedure.
Specify N in the command command on the PC screen, rotate the stepping motor 8 stepwise by the command number from the stepping motor control circuit in the interface control unit 9 via the driver, measure the rotation angle of the resolver at that time, and measure this. By repeating N times, the rotation angle of 360 degrees per rotation can be automatically measured. From the difference between the rotation angle measurement data and the rotation angle of the stepping motor, it is possible to calculate the rotation angle error data of 360 degrees per rotation.
In this example, the rotation angle of the resolver is acquired from the stepping speed of the stepping motor 8, but more accurately, a method of mounting a high-precision encoder on the same rotation axis and acquiring the rotation angle from it is used. Be done.

FIG. 3 shows a processing procedure of amplitude / phase adjustment and error interpolation correction of the rotation angle measurement control device 12.
Interpolation correction is made up of the following three main PHASEs.
Of these, the first two items are executed using the rotation angle measurement control device 12.
"SIN-COS drive signal-amplitude phase adjustment"
"First interpolation correction"
"Secondary interpolation correction": Independent execution of the modulated wave resolver device 1 Along with the procedure of this PHASE, its function and operation will be described below.

Regarding the PHASE of "SIN-COS drive signal-amplitude phase adjustment", first "amplitude adjustment control" and then "phase adjustment control" will be described.

There are structural deviations and manufacturing errors between the SIN series input coil of the resolver mechanical mechanism 7 and the coil composed of the internal printed circuit board between the stater that outputs the rotation angle θ from the COS series input coil and the rotor. Structural errors inside these resolvers appear as amplitude and phase inconsistencies in the output signals of the resolver.

As this correction, it is necessary to precisely adjust the amplitude and phase adjustment between the SIN series input coil and the COS series input coil on the drive circuit. Since this adjustment operation has been performed manually and by trial and error in the past, there is a limit to high-precision correction, and it takes time and effort. There is a need for rational means of high-precision amplitude and phase adjustment.

Structural errors inside the resolver manifest themselves as an amplitude or phase mismatch in the output signal of the resolver. Here, the amplitude correction is performed outside the resolver, and the voltage amplitude between the SIN series input coil and the COS series input coil is precisely adjusted to indirectly deal with the structural error inside the resolver. ..

The PHASE of "SIN-COS drive signal-amplitude / phase adjustment" will be described below with reference to FIGS. 4 to 8. FIG. 9 shows a flowchart of the amplitude / phase adjustment of the rotation angle.
(1) Collect N points of measurement error data (2) Tracking and tracking control using the minimization of the secondary or maximum error of the power spectrum as an index ⇒ Confirmation of amplitude / phase adjustment information ・ Transfer the adjustment information to the flash memory of the controller at this time The flash memory functions as the second storage element of the present invention.

FIG. 4 shows an example of the amplitude voltage adjustment circuit of the SIN series and the COS series.
In this example, as a driving method of the SIN series and the COS series, an example of driving the input coil by using a signed PWM circuit for generating a modulated wave is shown. The input coil of the resolver mechanism 7 is driven by the SIN-SW circuit 3 from the SIN series signal generation unit of the controller 2, and the other input coil is driven by the COS-SW circuit 4 from the COS series signal generation unit.

This example shows an example in which an amplitude adjustment is performed by incorporating a DAC (Digital Analog Converter: D / A converter) having a simple configuration by combining a DAC_PWM signal and a fluter as an amplitude voltage adjustment circuit.
In order to precisely adjust the amplitude between the SIN series input coil and the COS series input coil, it is necessary to adjust the amplitude to minimize the rotation angle error when the resolver mechanical mechanism is rotated once.

In this case, the voltage of the COS series is set to Vc = Vs ± ΔV based on the voltage Vs of the SIN series, and the voltage of the COS series is adjusted by searching for ± ΔV that minimizes the rotation angle error. Adjust the amplitude of the modulated wave SIN and COS. This operation has conventionally been performed manually and by trial and error.

Vc is obtained by controlling the output voltage of the DAC 5 from the controller 2. When the controller is an FPGA, the ΣΔ method may be used, but in this example, an example using a PWM-controlled D / A converter 5 having a simple configuration is shown. The DAC 5 operates by the command signal DAC_PWM signal from the controller 2 and controls Vc.
The optimum value of Vc is determined by using the rotation angle measurement control device described later, and is stored in the adjustment information of the flash memory in the controller as amplitude information, and Vc can be reproduced when the power of the controller is turned on.

Structural errors inside the resolver appear as inconsistencies in the amplitude and phase of the output signal of the resolver. The principle mechanism and error adjustment will be described.
The rotation principle of the modulated wave resolver is defined by the signal wave, and the operation is realized by the signal wave. The signal wave is composed of a sine wave and a cosine wave whose period is the reference signal, and expresses the basic operation of the resolver. The modulated wave of FIG. 13 is a carrier of the signal wave, and the envelope of the modulated wave is the signal wave.

When the rotation principle of the modulated wave resolver is expressed using a complex function, it is expressed as in Eq. (1), where the signal wave rotation angle is ωt and the resolver rotation angle is θ.

Expressing this relationship with Euler's formula connecting complex and trigonometric functions, the following trigonometric addition theorem can be obtained from the real and imaginary parts, respectively.

cosωt ・ cosθ−sinωt ・ sinθ ＝ cos (ωt ＋ θ) (2)
sinωt ・ cosθ ＋ cosωt ・ sinθ ＝ sin (ωt ＋ θ) (3)

Focusing on the equation (3) of the imaginary part, the zero cross point is considered (the rotation angle detection circuit 6 of the present invention also detects the phase at the zero cross point of the signal wave).
Since the zero cross point in Eq. (3) is sin (ωt−θ) = 0, it is when ωt−θ = 0, π.
Pay attention to the zero cross point on the side of ωt−θ = 0, and zero cross when θ = ωt. That is, the rotation angle θ can be obtained by measuring the rotation angle ωt that crosses zero.

"Amplitude adjustment control" will be described using a principle equation.
Pay attention to the left side of equation (3) and consider the zero cross point. When there is an amplitude difference between the SIN wave and the COS wave, the respective amplitudes are V1 and V2, the signal wave rotation angle is ωt, and the resolver rotation angle is θ, which can be expressed as follows.
(V1 sinωt) ・ cosθ ± (V2 cosωt) ・ sinθ ＝ 0 (4)
Here, the amplitude ratio of V1 and V2 is k = V2 / V1 = 1 + Δk.
When there is a difference of Δk in the amplitude ratio in this way, the rotation angle error Δθ as shown in Eq. (5) occurs in the rotation angle θ.
Δθ ≒ (90 / π) Δk sin2θ (degrees) (5)
The relationship between the rotation angle θ and the rotation angle error Δθ is shown in FIG.

Assuming that the resolution of the DAC is 10 bits, Δk = ΔV / Vs and Eq. (5) as a reference.
The resolution of the rotation angle error Δθ per bit is expressed by the following equation (6). From this, it is possible to perform amplitude adjustment with sufficient accuracy even with a DAC having a resolution of about 10 bits.
Δθ ≒ ± (90 / π) /1024 ＝ ± 0.028 degrees (6)

The characteristic of the rotation angle error Δθ due to the amplitude difference between the SIN wave and the COS wave is the Δk sin 2θ in Eq. (5). When the error distribution between the rotation angles 0 ° and 360 ° is Fourier transformed to analyze the higher-order error, the rotation angle error Δθ appears at the second order of the power spectrum. An example of the power spectrum of the rotation angle error is shown in FIG.
From this, when a remarkable numerical value appears in the second order, it indicates that the amplitude adjustment of the modulated wave SIN and COS is also one of the causes. On the contrary, the state in which the second-order power spectrum is minimized indicates the state in which the best amplitude adjustment is possible.

When the rotation angle of the resolver is θ and the Fourier series of the rotation angle error Δθ is shown on the sin side, it can be expressed as the following equation (7).
Δθ ＝ a0 ＋ a1 × sinθ ＋ a2 × sin2θ ＋ a3 × sin3θ ＋ a4 × sin4θ ＋ ・ ・ ・
(7)
Focusing on the Fourier series coefficients of Δθ (a0, a1, a2, a3, a4 ...), Each of the coefficients is related to the structural error factor of the resolver.
For example, a0 is the DC component and the error measurement offset, a1 is the eccentricity and inclination of the rotating axis of the resolver, a2 is the amplitude difference and orthogonal phase error between SIN and COS, and a1, a2, a3, and a4 are the mechanical mechanism structures. It is caused by each. In order to improve the accuracy of the rotation angle error of the resolver, it is necessary to improve these error factors.

Again, referring to FIG. 4, when applied to the example of the amplitude voltage adjustment circuit of the SIN series and the COS series, the mismatch of the internal mechanical structure of the mechanical mechanism of the resolver is corrected and adjusted by correcting the voltage on one side of the input coil. It is to balance with and deal with this.
In order to minimize the rotation angle error Δθ, observe the second-order value of the power spectrum as an index, track and control the output Vc (including ΔV) of the DAC so that this value is minimized, and minimize the value of Δθ. Will be adjusted to obtain.

CPU power is required for FFT calculation to obtain the second-order value of the power spectrum, but it is possible to import the measurement data into a PC and execute it online and in real time in about several ms.
As a means for minimizing the rotation angle error Δθ, the mechanism of amplitude adjustment by minimizing the power spectrum quadratic associated with Eq. (5) is the main point of the present invention.

"Phase adjustment control" will be described below with reference to FIGS. 7 and 8.
Here, the angular error of the orthogonality between the SIN series and the COS series is expressed as the phase error.
When there is a phase error, the phase is adjusted so as to cancel by the phase error.
As shown in FIG. 7, the means for adjusting the phase error is realized, for example, by phase-shifting the SIN curve with reference to the COS curve.

The principle formula of "phase adjustment control" will be described.
The equation for the rotation angle of the modulated wave resolver is again expressed as the following equation (3).
sinωt ・ cosθ ± cosωt ・ sinθ ＝ sin (ωt ± θ) (3)
Considering the zero cross point here
sinωt ・ cosθ ± cosωt ・ sinθ ＝ sin (ωt ± θ) ＝ 0
If the orthogonality between sinωt and cosωt is based on sinωt and there is an error of orthogonality Δ in cos, it becomes cos (ωt ± Δ). It is considered that the effect is expressed as (θ ± Δθ) from the rotation of the rotation angle θ.

Taking the − side of ± in Eq. (8), sin (sinωt-θ) = 0 to ωt = θ.

From this, equation (8) is shown as follows.

Here, the maximum of (θ ± Δθ) is θ = 90 degrees and 270 degrees at the points where sin θ = 1 and COS (θ ± Δ) = 0. The maximum value at that time is when Δθ = Δ.
That is, the maximum phase error is equal to the maximum rotation angle error.
For example, when the maximum rotation angle error Δθ = ± 1 degree, the maximum phase error Δ = ± 1 degree.
The rotation angle error Δθ due to the phase error Δ is shown in FIG.
In FIG. 8, there are two peaks of the rotation angle error between the rotation angles of 0 degrees and 360 degrees.
When this error pattern is Fourier analyzed, a peak appears prominently at the second order of the power spectrum as shown in FIG.

In order to minimize the rotation angle error Δθ, it is sufficient to observe the second-order value of the power spectrum as an index, track and control the phase so that this value becomes the minimum, and adjust so as to obtain the minimum value of Δθ. It will be. This indicates that the phase error, like the amplitude error, appears in combination at the second order of the power spectrum.

In general, the phase error has a smaller value than the amplitude error.
Therefore, as the order of control to minimize the rotation angle error Δθ, the amplitude error with a large rotation angle error is performed first, and after the error is sufficiently small, when the power spectrum quadratic value still remains. , The tracking control that minimizes the phase error is performed.
Finally, the amplitude error and the phase error are sorted so that the rotation angle error is minimized while observing the tendency of the rotation angle error to decrease.

FIG. 9 shows a flowchart of the amplitude / phase adjustment of the rotation angle.
The rotation angle measurement control device first acquires the measurement error data N points. Next, SIN-COS amplitude / phase adjustment is performed so that the secondary spectrum is the minimum or the amplitude of the error data is the minimum, and the amplitude information / phase information at that time is acquired. This amplitude information / phase information is transferred to the adjustment information of the flash memory of the controller 2 through the SPI bus.
This cycle is performed independently for SIN-COS amplitude adjustment and SIN-COS phase adjustment, and is completed when the secondary spectrum becomes the minimum or the amplitude of the error data becomes the minimum value, respectively.

The PHASE of the "first interpolation correction" will be described below with reference to FIGS. 10 and 11.
FIG. 10 is a diagram for explaining the process of the rotation angle error correction step, and FIG. 11 is a flowchart of the rotation angle error interpolation correction (first interpolation correction).
(1) Collect measurement error data N points (2) Third-order spline interpolation (3) Spline function calculation
Generate 2048 (11-bit) subdivided cells (4) Interpolation correction information: 2048 (11-bit) subdivided cells
Shaft type: Spline function calculation data Hollow shaft type: Inverse Fourier transform data (5) Transfer interpolation correction information to the flash memory of the controller

Even after structural correction of the resolver by SIN-COS amplitude / phase adjustment of the resolver, a relatively large rotation angle error (usually about ± 0.5 degrees to ± 1 degree) remains.
The means for further correcting this rotation angle error is to measure and collect the rotation angle error of 360 degrees per rotation of the resolver after SIN-COS amplitude / phase adjustment, and record this rotation angle error data in the flash memory in the controller. It is based on the principle that correction is performed by offsetting this value from the measured data.

Each resolver has a unique rotation angle error for each individual with respect to the number of decompositions of 360 degrees per rotation. The resolver is required to correct the rotation angle error with high accuracy due to the characteristics of the rotation sensor. However, it is not realistic to measure the number of decompositions with a measuring instrument and correct it because it becomes difficult to realize when the number of decompositions increases (16 bits: 65536 points in this example).
Therefore, in the present invention, the rotation angle error of N points (100 points in this example) that can be realistically measured after SIN-COS amplitude / phase adjustment is measured by the rotation angle measurement control device 12, and subdivided based on the measurement. , And finally, the resolution is accurately interpolated and corrected to the resolution corresponding to the number of resolutions of the resolver.

FIG. 10 shows the situation in the step of correcting the rotation angle error. The correction value for correcting the measurement error data is "1st interpolation correction": subdivision, "2nd interpolation correction": miniaturization, so that more accurate rotation angle interpolation information can be obtained by these two steps. It is the one that was done.
The "first interpolation correction" is executed by the rotation angle measurement control device 12, and the "second interpolation correction" is executed in the controller 2.

The first interpolation correction will be described with reference to the flowchart of the error interpolation correction (first interpolation correction) of the rotation angle of FIG.
In order to obtain the generated subdivided cell (correction data), first, the rotation angle measurement control device 12 collects N points of measurement error data between 0 degree and 360 degree for which SIN-COS amplitude / phase adjustment has been adjusted.
The measurement data is output from the SPI bus of the modulated wave resolver device 1. The measurement error data is represented by the difference between the measurement data and the rotation angle of the stepping motor.
Based on the measurement error data at N points, it is subdivided according to the capacity of the flash memory. This data is called a subdivided cell. The number of subdivided cells needs to be a binary number due to the relationship between the FFT operation and the BRM operation of linear interpolation later, and is set to 2048 in this example.
The generated subdivided cell is transferred as interpolation correction information to the flash memory of the controller 2 in the modulated wave resolver device 1 through the SPI of the interface control unit 9.

In the process of generating 2048 subdivided cells from the measurement error data N points, a means for generating 2048 subdivided cells interpolated so as to reduce the error from the discrete data of the measurement error data N points. Is a problem.
Therefore, first, as a means for connecting the measurement error data N points, it is rational to connect each point continuously with a curve as smooth as possible instead of a polygonal line as a means for reducing the error. In the present invention, at each connection point of adjacent error data, the points are continuously and smoothly connected by using third-order spline interpolation in which the data values match each other and the fine coefficients are the same.

A spline function is used to further subdivide the number of data points from the cubic spline interpolation that smoothly connects N points. The extension and subdivision of the error curve for one rotation from N points to 2048 points can be obtained by setting the calculation execution interval of the spline function to 2048. By the operation of this spline function, 2048 subdivided cells can be obtained.

Even after adjusting the amplitude and phase between the SIN-COS input coils, the modulated wave resolver still has a small rotation angle error. In addition to this, there are multiple factors of structural rotation angle error inside the resolver. In the shaft type, mechanical errors such as eccentricity and inclination angle of the resolver mechanical mechanism 7 are added.
There are the following two types of resolver rotation angle error correction.
・ For the shaft type, in addition to the structural rotation angle error inside the resolver,
Corrects the total rotation angle error including the eccentricity and tilt error of the rotation axis.
-For the hollow shaft type, the eccentricity and tilt errors of the rotating shaft are removed from the total rotation angle error, and only the structural rotation angle error inside the resolver is corrected.

The hollow shaft type will be described with reference to an example of a power spectrum having an angle of rotation error in FIG. In the order of the data series of the power spectrum after Fourier analysis, the structural rotation angle error inside the resolver is related to the higher order including the secondary power spectrum remaining after adjustment. It is a power spectrum. It is the first-order power spectrum that is related to the eccentricity and tilt error of the rotating shaft, and this term is separated in the hollow shaft type.

As this separation means, first, the average value of 2048 subdivided cells is taken and the DC component is deleted.
Next, this data series is Fourier analyzed using FFT. An inverse Fourier transform can be performed on a data series in which the complex data of the DC component and the first-order component of the result are set to 0, and a data series of 2048 points can be obtained. From this data series, the eccentricity of the rotation axis and the rotation angle error of the inclination are selectively deleted, and only the data series related to the structural rotation angle error inside the resolver is separated and left.
As for the range of the structural rotation angle error inside the resolver, it is possible to specify a specific higher-order range in addition to the DC component and the primary component to be deleted. For example, the inverse Fourier transform can be performed on a data series having a bandwidth such that the components other than the secondary component to the 32nd component are 0.

There are two types of "subdivided cells" of the interpolation correction information written in the flash memory, depending on the structure of the resolver.
(1) Shaft type data series subdivided by spline function calculation (2) Hollow shaft type data series subdivided by spline function calculation and Fourier transformed data series with only the primary component set to 0 This subdivided cell is transferred to the flash memory of the controller 2 through SPI as interpolation correction information.

The initial value of the data in the subdivided cell of the interpolation correction information of the flash memory in the controller 2 is set to 0. With this setting, raw data that does not involve subdivided cell data can be measured at the N point of the initial measurement error data. Interpolation correction data that cancels the measurement error raw data is set in the initial data of the subdivided cell after the initial execution loop.

At point N of the measurement error data of the next execution loop, a small measurement error (which offsets the initial measurement error) after the first correction interpolation involving the subdivided cell data is observed. The error does not become zero even if they are offset, because there is a small'deviation'between the actual error data in the operation by the first correction interpolation and the second correction interpolation.
This error component can be added with a sign to the previous interpolation correction information to correct and update the 2048 subdivided cell data in the interpolation correction information of the flash memory.
By repeating the execution feedback loop of this interpolation correction, the rotation angle error can be minimized and a higher rotation angle accuracy can be updated.

PHASE of "Second Interpolation Correction":
The improvement of accuracy by independently executing the modulated wave resolver device will be described below with reference to FIG.
(1) Acquire measurement data (16 bits in this example) (2) Linear interpolation From measurement data and subdivided cells
BRM calculation ⇒ Miniaturized to 65536 points (16 bits) (3) Calculated rotation angle information from miniaturized cell (4) Output corrected rotation angle information from SPI bus

The subdivided cell is obtained by optimally dividing the measurement error distribution between 0 degrees and 360 degrees into 2048 by executing a spline function operation in the measurement control device 12. After that, the 2048 subdivided cells are transferred to the flash memory of the controller 2 in the modulated wave resolver device 1 as interpolation correction information. When the power of the controller 2 is turned on, the interpolation correction information of the flash memory is transferred to the RAM, and high-speed calculation execution of the rotation angle information becomes possible.

In this example, the RAM address for storing the subdivided cells is 2048 (11 bits).
The upper 11 bits of the measurement data (16 bits in this example) of the resolver rotation position are assigned to the subdivided cells. At this stage, it can be assumed that the error is very small even if the adjacent subdivided cells are regarded as a straight line. On that premise, the lower 5 bits of the subdivided cell can be obtained by linear interpolation.
Rotation angle error data = subdivided cell data + linear interpolation data

With reference to FIG. 12, there are 5 bits (16 bits-11 bits = 5 bits) between the subdivided cells ei and ei + 1.
The actual measured data value (16-bit data) exists between the subdivided cells i and i + 1. Assuming that the lower 5 bits of the measured data value (16-bit data) are j, the lower 5 bits are the target interval of linear interpolation.
The 16-bit address is configured as follows.
Address 16 bits = 11 bits (subdivided cell section: RAM 2k) + 5 bits (linear complementary section)

If the address of the subdivided cell is i and the data is ei,
The adjacent difference data Δe of the subdivided cells is Δe = ei + 1−ei.
Further, assuming that the local address j in the linear interpolation interval (5 bits) is (j = 0 to 31), the linear interpolation value Δej at an arbitrary j is shown by Eq. (12) (Δej is). Has a ± sign).
Δej ＝ (Δe / 32) × j ＝ Δe × j / 32 (12)
Equation (12) is a method called BRM (Binary Rate multiplier), which uses binary numbers.
The division 1/32 can be calculated only by a simple operation of 5-bit right shift (conventionally, a divider was required).
From the above calculation, the miniaturized cell data indicating the correction value is indicated by (ei + Δej).

The corrected angle of rotation information is expressed by the following equation (13).
Rotation angle information = measurement data value-miniaturized cell data (ei + Δej) (13)
A resolver having a rotation angle decomposition number of 16 bits is miniaturized to 65536 points, and the corrected rotation angle information is obtained from this miniaturized cell.
The modulated wave resolver device 1 can output the corrected rotation angle information at that time to the outside from the SPI bus in response to the request of the external device.

Each subdivided cell having 2048 interpolation correction information in the memory has a linear information space of lower 5 bits. Since the lower linear processing is uniquely executed, it can be seen that the determination of the rotation angle error accuracy depends on the content of the correction information of the subdivided cell. Setting optimized correction data for the subdivided cells is a means of minimizing the rotation angle error accuracy.

The embodiment shown above is an example, and various modifications of the present invention can be considered without departing from the scope of claims. For example, in this embodiment, an example in which the input coil of the resolver is directly driven by a switch circuit is shown, but driving using a modulated wave is also within the scope of the present invention.
Needless to say, the various numerical values of the examples used for explanation are changed in the actual exercise of the patent.

The high-precision correction of the rotation angle error of the modulated wave resolver device of the present invention makes use of the features of the modulated wave resolver, such as small size, light weight, environmental resistance, and cost reduction.
Modulated wave resolver devices can be used as key components in AI robots, aerospace, information warehouses, machine tools, toys, and the like. In addition, it is promising as a general-purpose rotation sensor for the ICT revolution such as 5G as an IoT rotation sensor, and a large growth market can be expected in the future.

1 Modulated wave resolver device 2 Controller 3 Modulated wave generation circuit 4 Modulated wave generation circuit 5 Amplitude voltage adjustment circuit 6 Rotation angle detection circuit 7 Resolver mechanical mechanism 8 Stepping motor 9 Interface control unit 10 PC
11 Rotation angle information, adjustment information, interpolation correction information 12 Rotation angle measurement control device

Claims (14)

It is a method of detecting the rotation angle by a modulated wave resolver device.
A preparatory step for preliminarily storing rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device in the first storage element, and
Modulated wave generation signal output process that generates and outputs a modulated wave generation signal by a signal generator,
An input coil driving process in which a modulated wave signal is generated from a modulated wave generation signal by a modulated wave generation circuit and the input coil of the modulated wave resolver device is driven.
A rotation angle detection step of detecting the rotation angle from the output signal from the output coil of the modulated wave resolver device via the rotation angle detection circuit and outputting the rotation angle detection value.
The first section including the rotation angle detection value is determined from the rotation angle detection value, the rotation angle correction information at both ends of the first section stored in the first storage element is read out, and the rotation angle correction information is read. The rotation angle correction step of calculating the rotation angle correction value of the rotation angle detection value by linear interpolation of
A correction rotation angle output step of correcting the rotation angle detection value based on the rotation angle correction value and outputting the corrected correction rotation angle is provided.
Prior to the rotation angle correction step, at least one of the amplitude voltage adjustment information and the phase adjustment information stored in the second storage element is read out, and based on the read out information, the modulation wave is generated by the amplitude voltage adjustment circuit. It includes a rotation angle error adjusting step that controls the amplitude voltage of the modulated wave signal output from the circuit and / or controls the phase of the modulated wave generation signal output from the signal generator by the phase adjuster.
The amplitude voltage adjustment information and the phase adjustment information stored in the second storage element measure the error of the rotation angle of the resolver in advance, and the minimum amplitude voltage adjustment information and the minimum phase adjustment information that minimize the error. rotation angle detecting method characterized by comprising a. The minimum amplitude voltage adjustment information and the minimum phase adjustment information minimize the second-order component of the power spectrum of the rotation angle error obtained by Fourier-analyzing the rotation angle error of the resolver measured in advance. The rotation angle detection method according to claim 1 , wherein the amplitude voltage adjustment information and the phase adjustment information are used. The preparatory step includes a step of measuring an error in the rotation angle of the resolver and calculating an initial rotation angle error in a second section different from the first section.
A step of calculating the rotation angle error of the first section obtained by interpolating the rotation angle error of the second section and generating the rotation angle correction information, and a step of generating the rotation angle correction information.
The rotation angle detection method according to claim 1 or 2 , wherein the rotation angle correction information includes a step of storing the rotation angle correction information in the first storage element. The preparatory step includes a step of measuring an error in the rotation angle of the resolver and calculating an initial rotation angle error in a second section different from the first section.
Obtained by removing the first-order component of the power spectrum of the rotation angle error obtained by Fourier-analyzing the rotation angle error of the first section obtained by interpolating the rotation angle error of the second section. A step of calculating the rotation angle error of the first section by inverse Fourier transform from the obtained Fourier transform data and generating the rotation angle correction information.
The rotation angle detection method according to claim 1 or 2 , wherein the rotation angle correction information includes a step of storing the rotation angle correction information in the first storage element. It is a method of detecting the rotation angle by a modulated wave resolver device.
A preparatory step for preliminarily storing rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device in the first storage element, and
Modulated wave generation signal output process that generates and outputs a modulated wave generation signal by a signal generator,
An input coil driving process in which a modulated wave signal is generated from a modulated wave generation signal by a modulated wave generation circuit and the input coil of the modulated wave resolver device is driven.
A rotation angle detection step of detecting the rotation angle from the output signal from the output coil of the modulated wave resolver device via the rotation angle detection circuit and outputting the rotation angle detection value.
The first section including the rotation angle detection value is determined from the rotation angle detection value, the rotation angle correction information at both ends of the first section stored in the first storage element is read out, and the rotation angle correction information is read. The rotation angle correction step of calculating the rotation angle correction value of the rotation angle detection value by linear interpolation of
A correction rotation angle output step of correcting the rotation angle detection value based on the rotation angle correction value and outputting the corrected correction rotation angle is provided.
The preparatory step is obtained by measuring the rotation angle error of the resolver and calculating the initial rotation angle error in the second section different from the first section, and interpolating the rotation angle error in the second section. The rotation angle includes a step of calculating the rotation angle error of the first section and generating the rotation angle correction information, and a step of storing the rotation angle correction information in the first storage element. Detection method. It is a method of detecting the rotation angle by a modulated wave resolver device.
A preparatory step for preliminarily storing rotation angle correction information for correcting the rotation angle for each predetermined first section of the resolver of the modulated wave resolver device in the first storage element, and
Modulated wave generation signal output process that generates and outputs a modulated wave generation signal by a signal generator,
An input coil driving process in which a modulated wave signal is generated from a modulated wave generation signal by a modulated wave generation circuit and the input coil of the modulated wave resolver device is driven.
A rotation angle detection step of detecting the rotation angle from the output signal from the output coil of the modulated wave resolver device via the rotation angle detection circuit and outputting the rotation angle detection value.
The first section including the rotation angle detection value is determined from the rotation angle detection value, the rotation angle correction information at both ends of the first section stored in the first storage element is read out, and the rotation angle correction information is read. The rotation angle correction step of calculating the rotation angle correction value of the rotation angle detection value by linear interpolation of
A correction rotation angle output step of correcting the rotation angle detection value based on the rotation angle correction value and outputting the corrected correction rotation angle is provided.
The preparatory step is obtained by measuring the rotation angle error of the resolver and calculating the initial rotation angle error in the second section different from the first section, and interpolating the rotation angle error in the second section. From the Fourier conversion data obtained by removing the first-order component of the power spectrum of the rotation angle error obtained by Fourier analysis of the rotation angle error of the first section obtained, inverse Fourier conversion is performed to obtain the first rotation angle error. A rotation angle detection method comprising a step of calculating a rotation angle error of a section and generating the rotation angle correction information and a step of storing the rotation angle correction information in the first storage element. The initial rotation angle error is obtained as the difference between the rotation angle of the uncorrected resolver or the corrected correction rotation angle and the measured mechanical rotation angle , according to any one of claims 3 to 6. The described rotation angle detection method. A modulated wave resolver device for detecting the angle of rotation.
A signal generator that outputs a modulated wave generation signal, a first storage element that stores rotation angle correction information for correcting the detected rotation angle, and an arithmetic element that calculates the rotation angle correction value from the rotation angle correction information. A controller having a calculation unit including
A modulated wave generation circuit connected to the signal generator and generating a modulated wave signal from the modulated wave generation signal,
A resolver mechanical mechanism including an input coil driven by a modulated wave signal output from the modulated wave generation circuit and an output coil that outputs a rotation angle signal corresponding to the rotation angle of the resolver.
A rotation angle detection circuit that is connected to the output coil and outputs a rotation angle detection value from the rotation angle signal.
An amplitude voltage adjusting circuit for controlling the amplitude voltage of the modulated wave signal is provided.
The controller outputs a second storage element that stores amplitude voltage adjustment information and phase adjustment information, and an amplitude voltage adjustment signal for controlling the amplitude voltage adjustment circuit in response to the amplitude voltage adjustment information. A device and a phase adjuster for outputting a phase adjustment signal for controlling the phase of the modulated wave generation signal corresponding to the phase adjustment information are provided.
The rotation angle correction information stored in the first storage element is determined according to the rotation angle of each predetermined first section of the resolver.
The amplitude voltage adjustment information and the phase adjustment information stored in the second storage element measure the error of the rotation angle of the resolver in advance, and the minimum amplitude voltage adjustment information and the minimum phase adjustment information that minimize the error. Including
The arithmetic element determines the first section including the rotation angle detection value from the rotation angle detection value output from the rotation angle detection circuit, and the first section stored in the first storage element. By reading the rotation angle correction information at both ends of the above and linearly interpolating the read rotation angle correction information, the corrected rotation angle corrected for the rotation angle detection value is calculated and output from the output terminal of the controller. Modulated wave resolver device. The minimum amplitude voltage adjustment information and the minimum phase adjustment information minimize the second-order component of the power spectrum of the rotation angle error obtained by Fourier-analyzing the previously measured rotation angle error of the resolver. The modulated wave resolver device according to claim 8, wherein the amplitude voltage adjustment information and the phase adjustment information are provided. The rotation angle correction information stored in the first storage element is obtained by previously measuring the initial rotation angle error in the second section different from the first section and interpolating the rotation angle error in the second section. The modulated wave resolver device according to claim 8 or 9 , wherein the rotation angle error of the first section is included. The rotation angle correction information stored in the first storage element is obtained by previously measuring the initial rotation angle error in the second section different from the first section and interpolating the rotation angle error in the second section. It was obtained by inverse Fourier transform from the Fourier transform data obtained by removing the first-order component of the power spectrum of the rotation angle error obtained by Fourier analyzing the rotation angle error of the first section. The modulated wave resolver device according to claim 8 or 9 , wherein the rotation angle error of the first section is included. A modulated wave resolver device for detecting the angle of rotation.
A signal generator that outputs a modulated wave generation signal, a first storage element that stores rotation angle correction information for correcting the detected rotation angle, and an arithmetic element that calculates the rotation angle correction value from the rotation angle correction information. A controller having a calculation unit including
A modulated wave generation circuit connected to the signal generator and generating a modulated wave signal from the modulated wave generation signal,
A resolver mechanical mechanism including an input coil driven by a modulated wave signal output from the modulated wave generation circuit and an output coil that outputs a rotation angle signal corresponding to the rotation angle of the resolver.
A rotation angle detection circuit that is connected to the output coil and outputs a rotation angle detection value from the rotation angle signal is provided.
The rotation angle correction information stored in the first storage element is determined corresponding to the rotation angle of each predetermined first section of the resolver, and is initially determined in a second section different from the first section. The rotation angle error is measured in advance, and the rotation angle error of the first section obtained by interpolating the rotation angle error of the second section is included.
The arithmetic element determines the first section including the rotation angle detection value from the rotation angle detection value output from the rotation angle detection circuit, and the first section stored in the first storage element. By reading the rotation angle correction information at both ends of the above and linearly interpolating the read rotation angle correction information, the corrected rotation angle corrected for the rotation angle detection value is calculated and output from the output terminal of the controller. Modulated wave resolver device. A modulated wave resolver device for detecting the angle of rotation.
A signal generator that outputs a modulated wave generation signal, a first storage element that stores rotation angle correction information for correcting the detected rotation angle, and an arithmetic element that calculates the rotation angle correction value from the rotation angle correction information. A controller having a calculation unit including
A modulated wave generation circuit connected to the signal generator and generating a modulated wave signal from the modulated wave generation signal,
A resolver mechanical mechanism including an input coil driven by a modulated wave signal output from the modulated wave generation circuit and an output coil that outputs a rotation angle signal corresponding to the rotation angle of the resolver.
A rotation angle detection circuit that is connected to the output coil and outputs a rotation angle detection value from the rotation angle signal is provided.
The rotation angle correction information stored in the first storage element is determined corresponding to the rotation angle of each predetermined first section of the resolver, and is initially determined in a second section different from the first section. The first-order power spectrum of the rotation angle error obtained by measuring the rotation angle error in advance and Fourier-analyzing the rotation angle error of the first section obtained by interpolating the rotation angle error of the second section. From the Fourier transform data obtained by removing the order component, the rotation angle error of the first section obtained by the inverse Fourier transform is included.
The arithmetic element determines the first section including the rotation angle detection value from the rotation angle detection value output from the rotation angle detection circuit, and the first section stored in the first storage element. By reading the rotation angle correction information at both ends of the above and linearly interpolating the read rotation angle correction information, the corrected rotation angle corrected for the rotation angle detection value is calculated and output from the output terminal of the controller. Modulated wave resolver device. The initial rotation angle error is obtained as the difference between the rotation angle of the uncorrected resolver or the corrected correction rotation angle and the measured mechanical rotation angle , according to any one of claims 10 to 13. The modulated wave resolver device described.

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