JPH07110222A - Shape measuring instrument - Google Patents

Abstract

PURPOSE:To constitute a shape measuring instrument and reduce the cost of the instrument by irradiating a traveling object with laser light and calculating the shape of the object based on the intercepting time of the laser light. CONSTITUTION:Paired belt conveyors 1a and 1b are arranged with a clearance in between and move objects 10 to be measured (agricultural products). Laser light from a laser light outputting section 2 reaches a laser light receiving section 3 through the clearance between the conveyors 1a and 1b. The outputting section 2 reflects the laser light on a polygon mirror 1 and make the laser light to irradiate the objects 10 as parallel rays through a light projecting lens. When the objects 10 pass through the space between the sections 2 and 3, the laser light is intercepted. An arithmetic means measures the intercepting time of the laser light synchronously to pulse signals generated from an encoder and calculates the shapes of the objects 10 based on the intercepting time and moved amounts of the objects 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape measuring device for measuring the shape of an object to be measured such as agricultural products and processed parts.
In particular, the present invention relates to a shape measuring apparatus that scans and irradiates an object to be measured with laser light to measure the shape of the object to be measured.

[0002]

2. Description of the Related Art Conventionally, a shape measuring apparatus for measuring the shape of an object to be measured such as an agricultural product or a processed part acquires an image using a television camera device or the like, and an image such as contour extraction is applied to this image. It was general to perform a shape measurement after processing.

[0003]

However, the above-mentioned shape measuring device uses a television camera device and lighting, and thus becomes large in size, and the device for performing image processing is expensive and high in cost. Met. In addition, it was easily affected by ambient light, and measurement reliability was low.

On the other hand, the conventional laser outer diameter measuring device scans and irradiates a laser beam on the object to be measured to measure the outer shape and shake (position) of the object to be measured. It was not possible to measure the shape.

The present invention has been made in view of the above problems, and the apparatus itself can be constructed compactly, at low cost, less susceptible to the influence of ambient light, and can be measured. The object of the present invention is to provide a highly reliable shape measuring device.

[0006]

In order to solve the above-mentioned problems, a shape measuring apparatus according to the present invention comprises a moving means for moving an object to be measured and a laser for irradiating the object to be measured with laser light. A light output means, and a laser light receiving means arranged at a position facing the laser light output means with the object to be measured sandwiched therebetween,
And a calculation means for calculating the shape of the measured object based on the amount of movement of the measured object moved by the moving means and the time when the laser light received by the laser light receiving means is blocked by the measured object. Characterize that.

Further, in the shape measuring apparatus according to the present invention, the moving means is composed of a belt conveyor on which an object to be measured is mounted and moved, and an encoder for generating a pulse signal for each predetermined movement amount of the belt of the belt conveyor is provided. It is characterized in that the calculating means calculates the shape of the measured object by taking in the time when the laser light is blocked by the measured object in synchronization with the pulse signal.

Further, in the shape measuring apparatus according to the present invention, the calculating means, based on the output of the laser light receiving means, the time from the start of scanning of the laser light to the interruption of the laser light by the object to be measured, and the laser It is characterized in that the shape of the measured object is measured by the time when the light is blocked by the measured object.

[0009]

In the shape measuring apparatus according to the present invention, the moving means moves the object to be measured, the laser light output means scans and irradiates the object to be measured with laser light, and the laser light receiving means receives the laser light. . When the measured object passes between the laser light output means and the laser light receiving means, the laser light received by the laser light receiving means is blocked by the measured object. The calculation means measures the time when the laser beam is blocked, and calculates the shape of the measured object based on the cutoff time and the moving amount of the measured object moved by the moving means.

Further, in the shape measuring apparatus according to the present invention, the belt conveyor moves the object to be measured, the laser light output means scans and irradiates the object to be measured with laser light, and the laser light receiving means emits laser light. Receive light. The calculation means measures the time when the laser light is interrupted in synchronization with the pulse signal generated by the encoder, and calculates the shape of the object to be measured based on this interruption time and the moving amount of the object to be measured.

In the shape measuring apparatus according to the present invention, the moving means moves the object to be measured, the laser light output means scans and irradiates the object to be measured with laser light, and the laser light receiving means emits laser light. Receive light. The calculation means is the time from the start of scanning of the laser light until the laser light is blocked by the object to be measured,
The shape of the measured object is calculated based on the time when the laser light is blocked by the measured object and the moving amount of the measured object.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the shape measuring apparatus according to the present invention will be described in detail below with reference to the drawings. In this embodiment, the present invention is applied to an agricultural product sorting system in which the shape of an object to be measured, for example, an agricultural product, is measured and sorted.

As shown in FIG. 1, for example, this agricultural product sorting system is equipped with a belt conveyor 1 on which an object to be measured (hereinafter referred to as agricultural product) 10, which is an agricultural product such as kidney beans, is moved, and the belt conveyor 1. A pulse signal for each predetermined movement amount of the belt 51, for example, an incremental encoder 52, a laser light output unit 2 for scanning and irradiating the produce 10 with laser light, and a laser sandwiching the produce 10. From the laser light receiving portion 3 arranged at a position facing the light output portion 2, a measuring portion 65 for outputting the interruption time of the laser light as an analog voltage from the output of the laser light receiving portion 3, and the measuring portion 65 The data hold unit 66 that holds the analog voltage of, the moving amount of the agricultural product 10 that is moved by the belt conveyor 1, and the laser light from the start of scanning the laser light. Comprising time and until it is blocked by the object 10, and an arithmetic processing section 4 for calculating the shape of the agricultural products 10 based on the time and the laser beam is blocked by the agricultural product 10.

Further, this agricultural product sorting system separates the agricultural products 10 one by one on the upstream side of the belt conveyor 1,
A separation unit (not shown) for feeding in the feeding direction of the belt conveyor 1, an agricultural product sorting plate (not shown) for sorting the agricultural products 10 on the downstream side of the belt conveyor 1, and a solenoid of an actuator for driving the agricultural product sorting plate. And a solenoid drive unit 12 for exciting the agricultural products 10, and the agricultural products 10 are pushed out from the belt conveyor 1 by the agricultural product sorting plate based on the thickness, shape, etc. of the agricultural products 10 to perform sorting.

Further, the belt conveyor 1 is composed of a pair of belt conveyors 1a and 1b, for example, as shown in FIG. 3, and these belt conveyors 1a and 1b have a gap of 1 mm.
The agricultural products 10 are moved at a constant speed. And the belt conveyor 1a and the belt conveyor 1b
The laser light from the laser light output unit 2 reaches the laser light receiving unit 3 through the gap of. This belt conveyor 1a,
The gap 1b may be such that the agricultural products 10 to be moved do not fall and the laser light is not blocked.

More specifically, the laser light output section 2 comprises a semiconductor laser 61, a polygon mirror 62, a reflection mirror 63, and a light projecting lens 64, as shown in FIG. The agricultural product 10 is irradiated with the laser light scanned so that the laser light scanned by the reflection mirror 63 and the light projection lens 64 are parallel to each other.

As shown in FIG. 2, the laser light receiving section 3 is composed of a light receiving lens 67 and a light receiving element 68. The laser light scanned by the light receiving lens 67 is condensed to the light receiving element 68. The laser light received by the light receiving element 68 is converted into an electric signal and supplied to the measuring unit 65. Therefore, when the agricultural product 10 passes between the laser light output means 2 and the laser light receiving means 3, the laser light is blocked by the agricultural product 10 and the level of the electric signal supplied from the light receiving element 68 to the measuring section 65 decreases. To do.

The measuring section 65, as shown in FIG.
An edge detection circuit 30 which detects an edge of an output signal of the light receiving element 68 and outputs a latch signal, an optical sensor 32 which detects a laser beam and converts it into an electric signal, and the optical sensor 3
The waveform shaping circuit 33 for shaping the output waveform of No. 2, the clock pulse generating unit 34 for generating the clock pulse, the clock pulse from the clock pulse generating unit 34 is counted, and the waveform shaping circuit 33 resets the output waveform. Counter 35, a latch circuit 31 for holding the count value of the counter 35 by a latch signal from the edge detection circuit 30, a memory 38 storing various control programs, and a memory 38 stored in the memory 38. A central processing unit (hereinafter referred to as CPU) 36 that executes various control programs, a control input / output unit (control I / O) 39 that interfaces the CPU 36 with the processing unit 4, and the control of the CPU 36. Data display unit 40 for displaying and CPU 3
An analog output section 37 for converting the output of 6 into an analog signal
It has and.

The edge detecting circuit 30 is composed of, for example, a differentiating circuit or the like, detects an edge of the output signal of the light receiving element 68, and supplies a latch signal synchronized with the detected edge to the latch circuit 31. That is, the latch signal is supplied to the latch circuit 31 when the output signal of the light receiving element 68 rises and falls. For example, when the laser light is blocked by the produce 10, the first latch signal is output,
When the laser beam is received again, the second latch signal is output.

The optical sensor 32 is provided at the start end of the scanning range of the laser light, and supplies an electric signal to the waveform shaping circuit 33 when one scanning of the laser light is started.

The waveform shaping circuit 33 shapes the electric signal supplied from the optical sensor 32 and supplies a reset signal for resetting the counter 35 to the counter 35.

On the other hand, the clock pulse generator 34 generates a clock pulse and supplies the clock pulse to the counter 35.

The counter 35 is reset by the reset signal supplied from the waveform shaping circuit 33 and counts the clock pulses supplied from the clock pulse generator 34.

The latch circuit 31 holds (latches) the count value of the counter 35 by the first and second latch signals supplied from the edge detection circuit 30. For example, the latch circuit 31 includes two latches, and as shown in FIG. 4, for example, a count value corresponding to the length A is latched by the first latch signal, and the count value is length A + B by the second latch signal. Latch the corresponding count value.

The CPU 36 executes the control program stored in the memory 38 to cause the latch circuit 3 to operate.
The two count values latched in 5 are taken in and the first time information corresponding to the length A is output, and the difference between the two count values is obtained and the second time information corresponding to the length B is output. .

The analog output section 37 converts the first and second time information supplied from the CPU 36 into two analog voltages (hereinafter, referred to as voltage A and voltage B) of 0 to 5 V, and these voltage A , Voltage B to data hold unit 6
Supply to 6.

That is, the measuring section 65 determines, based on the output signal of the light receiving element 68, the time from the start of scanning the laser light until the laser light is blocked by the agricultural product 10, and the laser light is blocked by the agricultural product 10. The data hold unit measures the time between the scanning and the voltage A representing the time from the start of scanning until the laser light is blocked by the produce 10, and the voltage B representing the time during which the laser light is blocked by the produce 10. Supply to 66. Then, the data hold unit 66 holds the voltage A and the voltage B and supplies them to the arithmetic processing unit 4.

The arithmetic processing unit 4 includes the data holding unit 6 described above.
Produce 1 based on voltage A and voltage B supplied from 6
ROM 72 storing an arithmetic program for calculating the shape of 0, and CPU 7 for executing the arithmetic program
1, a RAM 73 for storing the shape and the like of the agricultural product 10 calculated by the CPU 71, and a voltage A and a voltage B from the data hold unit 66, which are digital data A
And convert to data B, for example, 12-bit analog /
A digital (hereinafter referred to as A / D) converter 75,
A data buffer RAM 74 for temporarily storing data A and data B from the A / D converter 75, an external I / F (parallel IN) 76 for inputting a pulse signal from the encoder 52 to the CPU 71, and the CPU 71 External I / C that controls the solenoid drive unit 12 by control
F (parallel OUT) 77. Also, the above CP
The U71 to the external I / F 77 are connected to each other by, for example, the VME bus 70.

Then, the CPU 71 has a data hold unit 66 supplied from the measuring unit 65 via the external I / F 76.
Of the belt 51 of the belt conveyor 1 in synchronization with the data strobe indicating that the voltage of the above is updated and the pulse signal supplied from the encoder 52, that is, for example, at regular intervals as shown in FIG. Data A and data B obtained by the A / D converter 75 are fetched for each C.
Specifically, the data A and the data B are fetched and stored in the data buffer 74, for example, every 200 microseconds. That is, in the data buffer 74, for example, as shown in FIG. 6A, data A representing the contour (length A) of the lower end of the discrete agricultural product 10 and, as shown in FIG. 6B, thickness (length B). ) Is stored.

The CPU 71 adds the data A and the data B to obtain the contour of the upper end of the agricultural product 10 at each sampling point as shown in FIG. 7, for example. Further, for example, as shown in FIG. 8, both ends of the agricultural product 10 and the center position M are calculated to determine the bending of the agricultural product 10.

Here, the A / D converter 7 of the CPU 71
The operation of fetching data A and data B from No. 5 will be described with reference to the flowchart shown in FIG.

In step S1, the CPU 71 resets the variable n indicating the sampling point number to 0, and proceeds to step S2.

In step S2, the CPU 71 detects whether the pulse signal from the encoder 52 is input,
When it corresponds, it progresses to step S3, and when it does not correspond, step S2 is repeated. That is, the process waits until the pulse signal is input in step S2.

In step S3, the CPU 71 inputs data A and data B (hereinafter referred to as A dimension and B dimension), and proceeds to step S4.

In step S4, the CPU 71 causes the B
The dimension is checked (determined). When the B dimension is 0, the process returns to step S2, and when it is not 0, the process proceeds to step S5.

That is, in the loop of steps S2 to S4, the CPU 71 detects that the agricultural product 10 has moved into the gap between the belt conveyors 1a and 1b as shown in FIG.

In step S5, the CPU 71 adds 1 to the variable n and proceeds to step S6.

In step S6, the CPU 71 stores the variable n, the A dimension, and the B dimension in the data buffer 74, and proceeds to step S7.

In step S7, the CPU 71 detects whether the pulse signal from the encoder 52 is input,
When it corresponds, it progresses to step S8, and when it does not correspond, step S7 is repeated.

In step S8, the CPU 71 causes A
The size and B size are stored in the data buffer, and step S
Proceed to 9. That is, in steps S7 and S8, the A dimension and the B dimension are fetched at regular intervals C.

At step S9, the CPU 71 causes the B
Check the dimensions, and if the B dimension is not 0, step S
Returning to 5, when 0, proceeds to step S10. That is, the operation of the loop of steps S5 to S9 is repeated until the agricultural product 10 passes through the gap between the belt conveyors 1a and 1b, the variables n, A dimension, and B dimension are input and stored in the buffer memory 74.

In step S10, the CPU 71
The execution of the arithmetic program is started, and the process returns to step S1.

As a result, during the driving of the belt conveyor 1, C
The PU 71 constantly monitors the presence or absence of the agricultural product 10, and the agricultural product 1
If 0 is present, the variable n for one produce 10,
The A dimension and the B dimension are sequentially input and stored in the data buffer 74.

Next, the operation of calculating the shape of the agricultural product 10 will be described with reference to the flowchart shown in FIG.

At step S20, the CPU 71
The variable A indicating the A dimension and the B dimension for each sampling point and the sample number is RA from the data buffer 74.
Transfer to M73 and proceed to step S21.

In step S21, the CPU 71
The length of the agricultural product 10 is calculated by multiplying the variable n by the constant interval C, and the process proceeds to step S22.

In step S22, the CPU 71
The maximum value of the B dimension is detected as the thickness of the agricultural product 10, and the process proceeds to step S23.

At step S23, the CPU 71
As shown in FIG. 8 described above, the both ends of the agricultural product 10 and the center position M are obtained, the bending of the agricultural product 10 is calculated, and step S
Proceed to 24.

In step S24, the CPU 71
It is determined whether the portion where the B dimension is small is at the beginning or at the end, the direction of the tip is obtained, and the process proceeds to step S25.

In step S25, the CPU 71
Based on the length, thickness, and bend, it is determined which sorting rank the agricultural product 10 corresponds to, and the process proceeds to step S26.

In step S26, the CPU 71
The solenoid drive unit 12 is controlled via the external I / F 77, and the process ends. Then, the solenoid drive unit 12 excites the solenoid that drives the agricultural product sorting plate 12. As a result, the agricultural products 10 are extruded from the belt conveyor 1 and sorted based on the sorting rank and the direction.

Further, this agricultural product sorting system is provided with an external I / F (serial) 78 such as a so-called RS-232C, and takes in the conditions of the sorting rank instructed from the host computer 9 to change the sorting rank from the outside. It is possible. Further, variables n, A dimension, B dimension and the like are sent to the host computer 9 through the external I / F (serial) 78, and the image of the agricultural product 10 is displayed on the display section of the host computer 9.

As is clear from the above description, this agricultural product sorting system (shape measuring device) uses a laser beam for shape measurement, and thus, compared with a conventional device using a video camera, an image processing device or the like. In addition to being compact, the cost can be reduced. In addition, it is less susceptible to the influence of ambient light, and the measurement reliability is high,
Maintenance can be performed easily.

The present invention is not limited to the above-mentioned embodiment, but the measuring section, the arithmetic processing section, and the host computer may be configured as one control section.
Further, for example, in addition to agricultural products, the shapes of processed parts and the like can be measured.

[0055]

As is apparent from the above description, in the present invention, the moving means moves the object to be measured, the laser light output means scans and irradiates the object to be measured with laser light, and the laser light receiving means. Receives the laser light, and the calculating means measures the time when the laser light is interrupted by the DUT passing between the laser light output means and the laser light receiving means, and the operation time and the moving means move the laser light. By calculating the shape of the object to be measured based on the moving amount of the object to be measured, the device can be configured more compactly and the cost can be reduced as compared with the conventional device using a video camera or the like. it can. Further, it is less susceptible to the influence of ambient light, and the reliability of measurement can be improved.

Further, in the present invention, the belt conveyor moves the object to be measured, the laser light output means scans and irradiates the object to be measured with laser light, the laser light receiving means receives the laser light, and the computing means. Measures the time when the laser light is blocked in synchronization with the pulse signal generated by the encoder, and calculates the shape of the measured object based on the cutoff time and the moving amount of the measured object. The object to be measured can be moved reliably, and the reliability of the measurement can be increased.

In the present invention, the moving means moves the object to be measured, the laser light output means scans and irradiates the object to be measured with laser light, the laser light receiving means receives the laser light, and the computing means. Is the time from the start of scanning of the laser light until the laser light is blocked by the DUT, the time when the laser light is blocked by the DUT, and the movement amount of the DUT based on the moving amount of the DUT. By calculating the shape, the shape of the measured object can be accurately measured.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an agricultural product sorting system to which the present invention is applied.

FIG. 2 is a block diagram showing a specific configuration of a laser light output unit and a laser light receiving unit that constitute the agricultural product sorting system.

FIG. 3 is a perspective view showing an actual usage state of the agricultural product sorting system.

FIG. 4 is a diagram for explaining an operation of a latch circuit that constitutes the agricultural product sorting system.

FIG. 5 is a diagram for explaining a data fetching operation of an arithmetic processing unit that constitutes the agricultural product sorting system.

FIG. 6 is a diagram showing an example of measurement data of agricultural products.

FIG. 7 is a diagram for explaining a calculation operation in the calculation processing unit.

FIG. 8 is a diagram for explaining the operation of shape calculation calculation in the calculation processing unit.

FIG. 9 is a flowchart showing a data input operation in the arithmetic processing unit.

FIG. 10 is a flowchart showing an operation of shape calculation in the arithmetic processing unit.

[Explanation of symbols]

1 ... Belt conveyor 2 ... Laser light output unit 3 ... Laser light receiving unit 4 ... Arithmetic processing unit 9 ... Host computer 10 ... Agricultural products 12 ... Solenoid drive unit 5 1. ..Belt 52 ... encoder 65 ... measuring unit 66 ... data holding unit 71 ... CPU 72 ... ROM 73 ... RAM 74 ... data buffer 75 ... A / D converter 76, 77, 78 ... External I / F

Claims (3)

[Claims] 1. A moving unit for moving an object to be measured, a laser light output unit for scanning and irradiating the object to be measured with a laser beam, and a unit for facing the laser light output unit with the object to be measured sandwiched therebetween. The laser light receiving means disposed at the position, the moving amount of the measured object moved by the moving means, and the time when the laser light received by the laser light receiving means is blocked by the measured object. A shape measuring device, comprising: a calculating means for calculating the shape of the object to be measured based on the shape measuring device. 2. The moving means comprises a belt conveyor that moves by mounting the object to be measured, and an encoder that generates a pulse signal for each predetermined movement amount of the belt of the belt conveyor is provided, and the computing means is the above-mentioned. The shape measuring apparatus according to claim 1, wherein the shape of the object to be measured is calculated by taking in the time during which the laser light is blocked by the object to be measured in synchronization with the pulse signal. 3. The calculation means, based on the output of the laser light receiving means, the time from the start of scanning of the laser light until the laser light is blocked by the object to be measured, and the laser light is the object to be measured. The shape measuring apparatus according to claim 1, wherein the shape of the object to be measured is measured by the time of interruption.