JP2007267480A - Servo control device and servo system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide servo control device that can improve the versatility of a main circuit module, that can achieve the cost reduction and model integration, and furthermore that can respond to different commands according to usage; in the servo control device that drives a motor with an encoder based on a command from outside. <P>SOLUTION: An interface module has a first operation means that inputs a position detection signal from the motor with the encoder, performs position or speed control operation based on the command and the position detection signal, and outputs a torque command and a control command for a motor electrical angle. The main circuit module has a second operation means that performs current control operation based on the control command, and outputs a drive signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a servo control device used for an FA, a robot and the like and a servo system using the servo control device.

In the conventional servo control apparatus, the first conventional example includes a main circuit module, an optional device net interface module, and a control circuit module, and performs speed control and position control of the motor to be controlled. It was configured as a substrate.
Further, in order to solve the problems of the first conventional example, the second conventional example includes a main circuit module and an optional interface module, and the main circuit module bridges the upper and lower semiconductor switches of each phase. And the internal phase command based on the position feedback from the position detection means attached to the motor or the current feedback from the current detection means, or the opening and closing of the upper and lower semiconductor switches for each phase of the inverter based on the phase command from the outside Drive signal generating means for generating a drive signal, and first interface means for serially transmitting a phase command or control information in the main circuit module with another module via a serial transmission path, and the interface module is connected to the host controller. Second interface means for receiving a speed command of: Control means for determining a phase command for the main circuit module based on the degree command, and third interface means for serially transmitting the phase command or control information in the main circuit module with the main circuit module via the serial transmission path, The control circuit module is provided, and speed control and position control of the motor to be controlled are performed, and each module is configured as a substrate. (See Patent Document 1).

  Further, in a conventional motor control system, as a third conventional example, a plurality of motors and a plurality of motors are provided for each of the plurality of motors, and a DC drive current is driven at a predetermined frequency according to a control signal input from the outside. A plurality of power conversion means for converting the current to be supplied to the motor; a position sensor provided in each of the plurality of motors for detecting a signal indicating the current position of the motor; and a speed command input from the outside Inverter control means for outputting the control signal to each of the plurality of power conversion means via a bi-directional serial communication line in accordance with a signal and a parameter set therein, and parameter setting for changing the setting of the parameter And a position command signal indicating the target position of the motor and a signal indicating the current position of the motor are input based on these signals. Position control means for outputting the speed command signal to the inverter control means, a host controller for outputting the position command signal and the parameter for controlling the rotation of the motor, and a second communication line to the host controller. And communication means for outputting the position command signal to the position control means and the parameter to the parameter setting means, respectively. (See Patent Document 2).

FIG. 4 is a schematic configuration diagram showing the servo control device of the first conventional example. In the figure, a main circuit module 500, an optional device net interface module 600, and a control circuit module 700 are provided to perform speed control and position control of a motor 511 to be controlled. Each module is configured as a substrate.
A variable speed driven motor 511 is provided with an encoder 512 as a means for detecting the rotational speed and position. The main circuit module 500 includes a converter 501, a CPU 502, a three-phase inverter 504, an interface 506, and a current detection resistor 507. The device net interface module 600 includes a device net interface unit 601, a CPU 602, and a two-port RAM 603. Further, the control circuit module 700 includes an AD converter 701, a CPU 702, a control circuit (ASIC) 703, parameter switches and LEDs 704, and an interface 705.

First, consider a configuration having only the main circuit module 500 and the control circuit module 700 (the configuration is not connected to the device net interface module 600).
In this case, an analog speed command is given to the control circuit module 700, converted into a digital speed command by the AD converter 701, read into the CPU 702, and a calculation result by a predetermined calculation is supplied to the control circuit (ASIC) 703. A gate drive signal GD is generated for on / off control of the upper and lower power transistors of the U-phase, V-phase, and W-phase of the three-phase inverter 504. The gate drive signal GD generated by the control circuit (ASIC) 703 is supplied to the three-phase inverter 504 of the main circuit module 500 via the isolators of the interfaces 705 and 506.

  Further, the current and voltage detected by the current detection resistor 507 of the main circuit module 500 are taken into the CPU 502 and reflected in the current control, etc., but the CPU 502 and the CPU 702 are coupled by a serial interface. Information such as current and voltage is input to the CPU 702 of the control circuit module 700 via the isolators of the interfaces 506 and 705 and reflected in speed control, vector control, and the like. Further, the speed or position detection information from the encoder 512 attached to the motor 511 is input to the control circuit (ASIC) 703 of the control circuit module 700 and used for feedback control. The parameter setting for motor control performed in the control circuit module 700 is input and output (confirmed) by a parameter switch and the LED 704, and an analog monitor output can be obtained from the control circuit (ASIC) 703. is there.

  Next, a configuration in which an optional device net interface module 600 is added will be considered. In the device net interface module 600, when a digital speed command is read into the CPU 602 via the device net interface unit 601, a calculation result by a predetermined calculation is written into the two-port RAM 603. On the other hand, the CPU 702 of the control circuit module 700 can access the 2-port RAM 603 via a signal line (including a data bus, an address bus, and a control signal group) 650, and the two CPUs 602 and 702 are coupled by the 2-port RAM 603. It is the structure which was made.

  As described above, in the first conventional example, the main circuit module, the option module (for example, the device net interface) and the control circuit module are configured to correspond to different commands (for example, the device net, analog signal, and pulse train) depending on the application. Yes.

FIG. 5 is a schematic configuration diagram showing a servo control device of a second conventional example, which solves a configuration that has a useless circuit portion depending on the application, which is a problem of the first conventional example. In the figure, a main circuit module 450 and a device net interface module 400 are provided to perform speed control and position control of a motor 460 to be controlled. Each module is configured as a substrate.
A variable speed driven motor 460 is provided with an encoder 470 as a means for detecting the rotational speed and position (position detecting means). The main circuit module 450 includes a converter 451, a CPU 452, a drive circuit (ASIC) 453, a three-phase inverter 454, a serial interface 455, and a current detection resistor 456. The device net interface module 400 includes a device net interface unit 401, a CPU 402, a control circuit (ASIC) 403, and a serial interface 404.

  Here, the CPU 452 and the drive circuit (ASIC) 453 in the main circuit module 450 are used for the internal phase command based on the position feedback from the encoder 470 attached to the motor 460 or the current feedback from the current detection resistor 456 or the device. Drive signal generation means for generating a gate drive signal GD for controlling on / off of the upper and lower power transistors of the U-phase, V-phase, and W-phase of the three-phase inverter 454 based on the phase command from the net interface module 400 Applicable. The serial interface 455 corresponds to first interface means for performing high-speed serial transmission via the serial signal line cable 410 for the phase command from the device net interface module 400 or the control information in the main circuit module 450.

  The device net interface unit 401 in the device net interface module 400 corresponds to second interface means for receiving a speed command from the host controller. The CPU 402 and the control circuit (ASIC) 403 are based on the speed command, and the main circuit module. The serial interface 404 corresponds to a third interface unit that performs high-speed serial transmission via the serial signal line cable 410 with respect to the phase command or the control information in the main circuit module 450. To do. Note that the serial interface 455 and the serial interface 404 are isolated by a pulse transformer or the like.

  As described above, in the second conventional example, a main circuit module and an interface module (for example, a device net interface) are configured, serial transmission is performed between the main circuit module and the interface module, and a command that varies depending on the application (for example, Device nets, analog signals, pulse trains, and other networks have the same main circuit module and can be handled by replacing the interface module. The problem of the first conventional example (main circuit module and option module (for example, device network) Interface) and a control circuit module, so that a configuration for receiving a digital command by connecting to a host controller on a one-to-one basis or a network drive having a multi-drop connection on a one-to-N basis ,option It corresponds by adding modules, at the time of the optional module mounted solves the circuit portion is a problem that a wasteful configuration) for analog interface.

  In the third conventional example (not shown), the power conversion means and the position control means are separated and configured as separate units, and data transmission between them can be performed by a bidirectional serial communication line. The power conversion means is a so-called main circuit unit including a converter, an inverter, and the like, and includes a communication interface. The position control means inputs a position detection signal from the rotation position sensor and a communication interface capable of serial communication with both the host controller that generates the command and the power conversion means, and performs position control calculation based on the command from the host controller. This is a so-called control unit having a position control unit and an inverter control circuit for driving an inverter of the power conversion means. The position control means can be connected to a plurality of power conversion means, and can drive a plurality of motors.

As described above, in the third conventional example, the power conversion means and the position control means are configured, serial transmission is performed between the power conversion means and the position control means, and when driving a plurality of motors, the position control means is provided. This is achieved by providing only the power conversion means corresponding to the number of motors, and the position control means is adapted to perform position control of a plurality of motors collectively.
JP 2002-345256 A (page 4-6, FIGS. 1 and 4) JP-A-6-141550 (page 4-7, FIG. 1)

As described in Patent Document 1, the first conventional example is composed of a main circuit module, an option module (for example, a device net interface), and a control circuit module. In order to achieve a configuration for accepting digital commands and a network drive configuration with multi-drop connection to 1 to N, an optional module is added, and when the optional module is installed, an analog interface is used. There is a problem in that the circuit portion of the configuration becomes useless.
The second conventional example is composed of a main circuit module and an interface module, so that in the case of different commands depending on the application, the main circuit module is made common and the interface module is changed to cope with the problem of the first conventional example. It has been solved. However, advanced control such as speed control and position control of the motor to be controlled is the main circuit module that inputs position feedback from the encoder, so it has a high capability that requires various control algorithms necessary for advanced control. There is a problem that it is necessary to have an arithmetic means and a high-performance peripheral circuit associated therewith, and it is impossible to reduce the cost. Further, since the main circuit module that can be shared is expensive, there is a problem that the versatility of the main circuit module cannot be improved.
The third conventional example is composed of power conversion means and position control means. A command is input from the host controller to the position control means via communication, and a position detection signal is input from the position sensor to the position control means. Since the control means performs position control calculation and the like, and outputs the PWM signal, that is, the gate drive signal to the power conversion means via communication, there is a problem that the load of calculation of the position control means becomes excessive. In particular, when a plurality of power conversion means for driving a plurality of motors are provided, there is another problem that the calculation load becomes excessive and a calculation means capable of withstanding this is required, which is expensive. In addition, since the position control means receives a command from the host controller via communication, it cannot cope with an analog command (for example, a speed command or a torque command) or a pulse train command (for example, a position command) that is also a standard application. There is also a problem. In addition, although the power conversion means can be used in common, there is also a problem that the functional performance of the power conversion means is low and general versatility in servo applications cannot be sufficiently obtained.

  The present invention has been made in view of such problems, and includes a configuration of a low-cost main circuit module and an interface module having an interface that can easily share the main circuit module. It is an object of the present invention to provide a servo control device that can improve the versatility of a circuit module, reduce the cost of the servo control device itself, integrate the models, and can cope with different commands depending on the application.

In order to solve the above problem, the present invention is configured as follows.
According to the first aspect of the present invention, there is provided an interface module having command input means for inputting a command from the outside and serial conversion means for converting the command into a serial signal, and the DC drive current is converted into an AC drive current based on the drive signal. In the servo control device, comprising: an inverter for converting to a main circuit module having a current detection means for detecting a motor driving current; and performing data transmission between the interface module and the main circuit module by bidirectional serial communication. The interface module includes first calculation means for inputting a position detection signal from a motor with an encoder, performing position or speed control calculation based on the command and the position detection signal, and outputting a control command, The circuit module performs a current control calculation based on the control command, and And has a second arithmetic means for outputting a driving signal.
According to a second aspect of the present invention, the control command output by the interface module according to the first aspect is a torque command and a motor electrical angle command.
According to a third aspect of the present invention, when the signal form of the command from the outside according to the first aspect is changed, or when the signal form of the position detection signal from the motor with an encoder is changed, the interface Only the module is replaced with one provided with input means corresponding to each signal form, and the main circuit module is used without replacement.
According to a fourth aspect of the present invention, there is provided an interface module having command input means for inputting a command from the outside and serial conversion means for converting the command into a serial signal, and the DC drive current is converted into an AC drive current based on the drive signal. And a main circuit module having a current detecting means for detecting a motor driving current and an inverter that converts the data to the interface module and the main circuit module in a two-way serial communication. Is a control command that is a torque command and a motor electrical angle command, and the main circuit module has a calculation means for performing a current control calculation based on the control command and outputting the drive signal. is there.
The invention according to claim 5 includes the servo control device according to claim 4, a motor with an encoder that outputs a position detection signal, and a host device that inputs the position detection signal and outputs the command. Is.
The invention according to claim 6 is an interface module having command input means for inputting a command from the outside, an inverter for converting a DC driving current into an AC driving current based on a driving signal, and a current detection for detecting the motor driving current. A servo control device for performing data transmission between the interface module and the main circuit module by bidirectional serial communication, wherein the interface module receives a position detection signal from a motor with an encoder. Input means for inputting, and first calculation means for converting the command into a serial signal and outputting the serial signal, and the main circuit module performs servo control calculation based on the command and the position detection signal, It has a 2nd calculating means which outputs the said drive signal.
According to a seventh aspect of the present invention, when the signal form of the command from the outside according to the sixth aspect is changed, or the signal form of the position detection signal from the motor with an encoder is changed, the interface Only the module is replaced with one provided with input means corresponding to each signal form, and the main circuit module is used without replacement.

According to the first and fourth aspects of the invention, the main circuit module can be made inexpensive, and the main circuit module can be shared beyond the application. In other words, the main circuit module can be used for servo control applications and inverter control applications (applications such as simple variable speed), enabling model integration, improving versatility, and further reducing costs. Can be achieved.
According to the second aspect of the present invention, the main circuit module can be shared and the cost can be reduced more easily.
According to the third and seventh aspects of the invention, it is possible to easily cope with various command signal forms and various position detection signal forms while maintaining the main circuit module in common.
According to the fifth aspect of the present invention, it is possible to easily develop multi-axis control that includes a plurality of servo control devices and motors with encoders.
According to the sixth aspect of the present invention, it is possible to configure a high-function servo control device having a common main circuit module.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a servo control apparatus showing a first embodiment of the present invention. In the figure, 100 is an interface module, 101 is an A / D converter, 102 is a first calculation means, 103 is an isolator, 104 is a display setting unit, 150 is a main circuit module, 151 is a converter, and 152 is a second calculation. Means 153 is an inverter, 154 is a current detection resistor, and 200 is a motor with an encoder.
The present invention is different from Patent Document 1 and Patent Document 2 in that the interface corresponding to the command from the outside, the position detection signal from the motor with encoder 200 is input, and the servo calculation processing of position or speed control is performed. A calculation setting unit 102 and a display setting unit 104 for setting and displaying parameters relating to servo calculation, sequence, alarm, etc. are provided, and control commands (torque commands and electrical angle commands) based on external commands are serialized to the main circuit module 150. Interface module 100 that outputs as a signal or inputs a signal such as an alarm from the main circuit module 150 as a serial signal, and inputs a control command (torque command and electrical angle command) to calculate a sequence or alarm, current control, etc. A second computing means 152 for processing, and a motor with an encoder; A main circuit module 150 supplies power for driving the 200, a portion with a.

  In FIG. 1, the operation of the servo control apparatus according to the first embodiment of the present invention will be described. In the figure, the first embodiment is an embodiment in the case where the command from the outside is an analog signal. When the command from the outside is a communication command such as a device net, the A / D converter 101 portion is a communication interface. (Pulse transformer, line driver receiver, etc.) When the external command is a pulse train position command, the A / D converter 101 is replaced by a pulse train interface (pulse counter, line receiver, etc.). Similarly, in the case of other commands, a corresponding interface is used, so that various external commands can be handled only by the interface unit 100.

  When an analog command voltage from the outside is input to the interface module 100, it is input to the A / D converter 101, converted into a digital command, and input to the first calculation means 102. Further, a position detection signal from the motor with encoder 200 is also input to the first calculation means 102. Here, the position detection signal is a position feedback signal required for servo calculation of any one of a serial signal, a pulse signal, and an analog signal, and in the case of a signal form that cannot be directly input to the first calculation means 102, the corresponding signal is detected. The data is input to the first calculation means 102 via the interface. The display setting unit 104 sets and displays parameters related to servo calculations, sequences, alarms, etc., and writes setting data to the first calculation means 102 or display data from the first calculation means 102. Used as a display tool. Here, the display setting unit 104 may be outside the interface module 100, and in that case, is connected to the first calculation means 102 via a connector or the like.

  The first calculation means 102 performs servo calculation processing for position or speed control based on setting data such as a digital command, a position detection signal, and a parameter, and outputs a control command (a torque command and an electrical angle command). Control commands (torque command and electrical angle command) are input to the main circuit module 150 via the isolator 103. The first calculation means 102 is composed of a CPU, an ASIC, and its peripheral control circuit. Since the first calculation means 102 performs servo calculation processing, the CPU needs to have a relatively high performance.

When a control command (torque command and electrical angle command) is input to the main circuit module 150, it is input to the second calculation means 152. In addition, a current detection signal (current feedback signal) from a current detection resistor 154 disposed on the lower arm of the inverter 153, an alarm signal from an alarm detection circuit (not shown), and the like are also input to the second arithmetic means 152.
The second calculation means 152 performs a current control calculation based on the control command (torque command and electrical angle command) and the current detection signal, outputs a drive signal (gate drive signal) to the inverter 153, and based on an alarm signal or the like. The sequence or alarm signal is output to the interface module 100 as a serial signal. The second computing means 152 is composed of a CPU, an ASIC, and its peripheral control circuit. Unlike the first computing means, the CPU may have a relatively low performance. Cost reduction can be achieved. The current control calculation is performed by the ASIC.
The inverter 153 outputs a drive current based on the drive signal to drive the encoder-equipped motor 200.

FIG. 2 is a schematic configuration diagram of a servo control apparatus showing a second embodiment of the present invention. In the figure, 300 is an interface module, 301 is a line driver receiver, and 350 is a host controller. In addition, since the component which attached | subjected the same code | symbol as FIG. 1 operate | moves similarly, description is abbreviate | omitted.
The present invention is different from the first embodiment in that a host controller 350 that inputs a position detection signal from the motor 200 with an encoder and outputs a control command (a torque command and an electrical angle command) is arranged outside the servo control device. An interface module 300 is provided that receives a control command (a torque command and an electrical angle command), converts the command into a serial signal, and outputs the serial signal to the main circuit module 150 via the isolator 103.

  The second embodiment is effective when applied to multi-axis control including a plurality of motor-equipped encoders and servo control devices. In particular, the host controller 350 is used in applications that require coordinated operations between axes such as robots. After performing coordinated control of the entire shaft, the control commands (torque command and electrical angle command) are output to the servo control device for each shaft. Therefore, the servo control device for each axis includes an interface module 300 that converts a control command (torque command and electrical angle command) into a serial signal by the line driver receiver 301 and outputs the serial signal to the main circuit module 150 via the isolator 103. The main circuit module 150 can be the same as that of the first embodiment, can be used in common with the main circuit module 150 for each application, and further leads to cost reduction and versatility improvement. Can do it.

FIG. 3 is a schematic configuration diagram of a servo control apparatus showing a third embodiment of the present invention. In the figure, 250 is an interface module, 252 is another first computing means, 251 is an isolator, 155 is a main circuit module, and 156 is another second computing means. In addition, since the component which attached | subjected the same code | symbol as FIG. 1 operate | moves similarly, description is abbreviate | omitted.
The present invention is different from the first embodiment in that it has an isolator 251 for isolating a position detection signal from another encoder 200 and an encoder-equipped motor 200 instead of the first calculator in FIG. The interface module 250 and a main circuit module 155 having another second calculation means 156 instead of the second calculation means in FIG. 1 are provided.

Unlike the first embodiment, the third embodiment performs servo calculation processing functions for position, speed, and current control in the main circuit module 155, and provides a command form (analog signal, pulse train, communication, etc.) from the outside, In accordance with the position detection signal form (serial signal, pulse signal, analog signal, etc.) from the motor 200 with encoder, these signals are converted into serial signals and output to the main circuit module 155 by the interface module 250. Is.
Another second calculation means 156 is composed of a CPU, an ASIC, and its peripheral control circuit, and controls the servo calculation process, so that the CPU needs to have a relatively high performance. Further, arithmetic processing such as sequence and alarm is performed by the CPU, and current control calculation is performed by the ASIC. Further, the different first calculation means 252 is composed of an ASIC and its peripheral control circuit, and unlike the second calculation means, the cost can be reduced.

  Therefore, the main circuit module 155 having the main servo arithmetic processing function is made common, leading to improvement in versatility and cost reduction, and a serial signal according to an external command form and a position detection signal form from the motor 200 with an encoder The cost of the interface module 250 having a conversion function can be reduced. In this case, the serial signal from the interface module 250 to the main circuit module 155 includes an external command, a position detection signal from the motor 200 with encoder, setting data in the display setting unit 104, and the like.

  The serial signals exchanged between the interface module and the main circuit module in the first to third embodiments are control commands (torque commands and electrical angle commands), position detection signals, setting data and display data of the display setting device 104, and sequences. Although signals such as alarms and alarms are described as examples, this is not restrictive. For example, the control information (position, speed feedback, alarm signal, etc.) of other axes in applications that require coordinated operations between axes such as the robot described in the second embodiment is input from other axes. By exchanging this between the interface module and the main circuit module, it is possible to perform non-interference control between the axes in the servo control calculation, and desired cooperative control can be performed without relying on an external host controller.

It is a schematic block diagram of the servo control apparatus which shows the 1st Example of this invention. It is a schematic block diagram of the servo control apparatus which shows the 2nd Example of this invention. It is a schematic block diagram of the servo control apparatus which shows the 3rd Example of this invention. It is a schematic block diagram of the servo control apparatus which shows a 1st prior art example. It is a schematic block diagram of the servo control apparatus which shows a 2nd prior art example.

Explanation of symbols

100, 250, 300 Interface module 101 A / D converter 102, 252 First computing means 103, 251 Isolator 104 Display setting device
150, 155 Main circuit module 151 Converter 152, 156 Second arithmetic means 153 Inverter 154 Current detection resistor 200 Motor with encoder 301 Line driver receiver 350 Host device

Claims (7)

An interface module having command input means for inputting a command from the outside and serial conversion means for converting the command into a serial signal, an inverter for converting a DC drive current into an AC drive current based on the drive signal, and a motor drive current A servo control device for performing data transmission between the interface module and the main circuit module by bidirectional serial communication.
The interface module has a first calculation means for inputting a position detection signal from a motor with an encoder, performing a position or speed control calculation based on the command and the position detection signal, and outputting a control command;
The servo control device according to claim 1, wherein the main circuit module includes second calculation means for performing current control calculation based on the control command and outputting the drive signal.   The servo control device according to claim 1, wherein the control command output by the interface module is a torque command and a motor electrical angle command. When the signal form of the command from the outside is changed, or when the signal form of the position detection signal from the motor with an encoder is changed,
2. The servo control apparatus according to claim 1, wherein only the interface module is replaced with one having an input unit corresponding to each signal form, and the main circuit module is used without being changed. An interface module having command input means for inputting a command from the outside and serial conversion means for converting the command into a serial signal, an inverter for converting a DC drive current into an AC drive current based on the drive signal, and a motor drive current A servo control device for performing data transmission between the interface module and the main circuit module by bidirectional serial communication.
The command from the outside is a control command that is a torque command and a motor electrical angle command,
The servo control device according to claim 1, wherein the main circuit module has a calculation means for performing a current control calculation based on the control command and outputting the drive signal.   5. A servo system comprising: the servo control device according to claim 4; a motor with an encoder that outputs a position detection signal; and a host device that inputs the position detection signal and outputs the command. An interface module having command input means for inputting a command from the outside; a main circuit module having an inverter for converting a DC drive current into an AC drive current based on a drive signal; and a current detection means for detecting a motor drive current; In a servo control device that performs data transmission between the interface module and the main circuit module by bidirectional serial communication,
The interface module includes input means for inputting a position detection signal from a motor with an encoder, and first calculation means for converting the command into a serial signal and outputting the serial signal.
The servo control device, wherein the main circuit module includes second calculation means for performing a servo control calculation based on the command and the position detection signal and outputting the drive signal. When the signal form of the command from the outside is changed, or when the signal form of the position detection signal from the motor with an encoder is changed,
7. The servo control device according to claim 6, wherein only the interface module is replaced with one having input means corresponding to each signal form, and the main circuit module is used without being changed.

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