JP2005127728A - Method for diagnosing and displaying state of mounting of position detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and highly accurately mount a sensor head, to make the time required for assemble work and the work of adjusting positions efficient, to verify the adhesion of dust and the state of characteristics degradation of a detecting member, and to efficiently perform the work of detecting positions. <P>SOLUTION: A signal outputted from each detecting part when the sensor head is mounted to a body to be detected in a normal state is taken as a reference value. Signals outputted from the detecting parts of the sensor head are compared with the reference value to perform diagnosis. The display of a display means for performing multi-stage display of at least three stages on the results of the diagnosis on the state of mounting of the sensor head to a mobile body is controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a position provided in a separation type sensor head that is detachably attached to a moving body and detects a moving amount (moving amount) of the moving body when closed-loop control is performed on a servo motor that moves the moving body. The present invention relates to a detection state display method for a detection device.

  As a conventional position detection device, for example, as shown in Non-Patent Document 1, a large number of light transmitting portions and light blocking portions are alternately provided at a concentric position of a disk attached to a rotation shaft of a servo motor, and from one side of the disk. The moving position of the moving body is detected based on the amount of rotation of the disk by an electrical signal output when the irradiated light passes through the light transmitting part and is received by a plurality of light receiving parts provided on the other side of the disk. doing.

  In this position detection device, the sensor head provided with the detection unit and the detected part are integrated to ensure the parallelism between them and maintain the detection accuracy. However, in order to reduce the cost, the sensor head and the detected part are detected. The parts are separable, and the parallelism and inclination of both are adjusted when attaching to the moving body to ensure detection accuracy.

However, the above-described separation type sensor head requires a high level of skill to adjust the parallelism and inclination with respect to the detected object, and requires time and labor for the mounting work. Has a problem that gets worse.

In addition, because the sensor head itself is separated from the moving body, the sensor head mounting position is shifted due to vibrations associated with use over time, and the detection unit characteristics deteriorate due to use over time or dust adhesion. The position cannot be detected with. In the former case, it is necessary to adjust the mounting position of the sensor head, but even in this case, a high level of skill is required for the position adjustment work as described above, and the adjustment work takes time and effort. have. In the latter case, when the position detection becomes defective, it is necessary to remove the sensor head and remove dust, or after replacing the detection member, it is necessary to reattach it while positioning it. It took time and effort.
Jiro Otsuka “Positioning Design Feature” published by Nikkei Business Publications, October 2002 No. 577

The problem to be solved is that in order to detect the position with high accuracy, it is necessary to attach the sensor head to the detection target in a normal state, but it is expensive to attach or adjust the sensor head in a normal state. The skill level is required, and the work takes a lot of time and effort, and the workability is poor. In addition, the position cannot be detected with high accuracy due to deterioration of the characteristics of the detection unit due to use over time, dust adhesion, or the like.

The present invention uses, as a reference value, a signal output from each detection unit when the sensor head is attached to the detection target in a normal state, and a signal output from the detection unit of the sensor head and the reference value. The comparison is diagnosed, and the diagnostic information is displayed on the display means.

  According to the present invention, the sensor head can be attached and adjusted easily and with high accuracy, and the assembly work time and the position adjustment work can be made efficient. Further, it is possible to check the state of dust adhesion and the deterioration of the characteristics of the detection member, and the position detection work can be performed efficiently.

The present invention uses, as a reference value, a signal output from each detection unit when the sensor head is attached to the detection target in a normal state, and a signal output from the detection unit of the sensor head and the reference value. In comparison, the sensor head is diagnosed as to whether the sensor head is attached, and display means for displaying the diagnosis result in multiple stages in at least three stages is controlled.

The present invention will be described below with reference to the drawings showing embodiments.
The present embodiment shows an example of position detection using a position detection signal as image data. In FIGS. 1 and 2, the moving body 1 is supported so as to reciprocate in the longitudinal direction of the main body frame 3, and the moving body 1 is moved in a numerically controllable manner by a servo motor and a known rotary reciprocating drive mechanism (for example, a rotary reciprocating drive mechanism such as a ball screw and nut, a pulley and a belt, a rack gear and a pinion gear, etc., not shown).

  A scale 5 is attached to the main body frame 3 along the longitudinal direction, which extends in the longitudinal direction and forms a body to be detected with a length that substantially matches the moving distance of the moving body 1. The scale 5 is formed with a large number of light transmitting portions 5a and light blocking portions 5b, each having a longitudinal width of, for example, two pixels of the image sensor 9 described later.

  A sensor head 7 is attached to the moving body 1 so as to be detachable. The sensor head 7 is detachably attached to the moving body 1 and has a pair of upper and lower arms 7a and 7b opposed to each other with the scale 5 interposed therebetween. For example, the upper arm 7a has a predetermined number of pixels in the longitudinal direction. A light irradiation unit such as an LED that irradiates light toward a position corresponding to a middle part in the longitudinal direction of the image sensor 9 on the lower arm 7b. 11 are respectively attached.

  In addition, on the upper surface of the arm 7a of the sensor head 7, indicator lamps 13a, 13b, and 13c are provided as display means for emitting, for example, blue, yellow, and red light. The sensor head 7 includes a detection control means 15.

As shown in FIG. 3, the detection control means 15 has a CPU 17, a program memory 19, and a work memory 21. The program memory 19 includes program data for executing the movement position detection operation of the sensor head 7 and a sensor head for the scale 5. Program data for detecting the mounting position state 7 is stored.

Further, the work memory 21 stores a reference data area 21a as a storage unit that stores reference image data in a misalignment state when detecting a misalignment of the sensor head 7 with respect to the scale 5, and image data from the image sensor 9 during position adjustment. Has a buffer area 21b.

The reference data stored in the reference data area 21a is such that the sensor head 7 has the pixel array direction of the image sensor 9 and the longitudinal direction of the scale 5 coincide with each other, and the gap of the image sensor 9 with respect to the scale 5 is a predetermined interval. The first reference image data when set to the normal state, the second reference image data when it is not normal but the tolerance is not necessary until position adjustment, and the third reference image when the mounting position is not completely normal Data.

The work memory 21 has various areas for storing data necessary for detecting the amount of movement of the moving body 1 by the image sensor 9, and details thereof are described in Japanese Patent Application No. 2002-361615. Therefore, the description thereof is omitted.

An image sensor 9 and a light irradiation unit 11 are connected to the detection control means 15 via an interface 23. The light irradiation unit 11 is appropriately driven for each pulse and a CCD or a photodiode constituting each pixel of the image sensor 9. The electric signal output from is read in synchronism with the pulse, and when the electric signal is equal to or higher than a predetermined threshold voltage, A / D conversion is performed to generate image data as position detection data.

  The detection control means 15 is connected to display control means 25 connected to the respective indicator lamps 13a, 13b, 13c. The display control means 25 is connected to the detection head 15 from the image sensor 9 when the sensor head 7 is attached or adjusted. The output image data is compared with the reference image data stored in the reference data area 21a. When the two are almost the same, for example, the blue indicator lamp 13a is displayed. When the lamp 13b is completely displaced, the red indicator lamp 13c is selectively lit to display the attached diagnosis result.

  The sensor head 7 may contain batteries (not shown) for turning on the indicator lamps 13a, 13b, and 13c, and may be turned on by a power source other than the sensor head 7 (not shown). Of course, it may be. In the case where a controller (not shown) for controlling the movement of the moving body 1 is provided outside the moving body 1, the above-described instruction lamps 13a, 13b, 13c are provided on the controller, and these are also detected and detected by the control means 15. May be connected by a signal cable 27 (indicated by a one-dot chain line in FIG. 3).

  Next, a diagnostic display method for the mounting state of the sensor head 7 will be described. The operation of detecting the moving amount of the moving body 1 as an absolute value based on the image data from the image sensor 9 of the present embodiment is described in detail in the above-mentioned Japanese Patent Application No. 2002-361615. Description is omitted.

  First, a method of attaching the separation type sensor head 7 to the moving body 1 assembled to the main body frame 3 will be described. In the reference data area 21a, the sensor head 7 is properly attached to the scale 5 of the moving body 1. That is, the sensor head 7 is output from the image sensor 9 when the pixel arrangement direction of the image sensor 9 and the longitudinal direction of the scale 5 coincide with each other and the gap of the image sensor 9 with respect to the scale 5 is set to a predetermined interval. The first reference image data is the first reference image data, and the image data output from the image sensor 9 is the second reference image data when the tolerance is not necessary but the position adjustment is not necessary. The mounting position deviates completely from the normal state. The image data output from the image sensor 9 when the position detection is defective is used as the third reference. Stored in advance as the image data (see FIG. 4).

Then, after temporarily fixing the sensor head 7 to the moving body 1, the light irradiation unit 11 is driven to be irradiated at every desired pulse in step 51 shown in FIG. 6, and image data from the image sensor 9 is synchronized with this pulse. Is stored in the buffer area 21b. Next, in step 52, it is determined whether or not the image data stored in the buffer area 21b matches the first reference image data among the respective reference image data stored in the reference data area 21a.

Now, in the temporarily fixed state of the sensor head 7 with respect to the moving body 1, for example, as shown in FIG. 5, the sensor head 7 is not in the normal attachment position state but inclined with respect to the longitudinal direction. The first reference image data stored in the data area 21a and the image data stored in the buffer area 21b do not match, so that the above step 52 becomes NO, and then the image data stored in the buffer area 21b by step 53 Is equal to the second reference image data stored in the reference data area 21a.

If the mounting position of the sensor head 7 with respect to the moving body 1 is within the allowable range, the determination at step 53 is YES, and the yellow indicator lamp 13b is turned on at step 54. On the other hand, if the mounting position of the sensor head 7 with respect to the moving body 1 is displaced to an allowable range, the determination is NO, and the red indicator lamp 13c is turned on in step 55.

If the first reference image data stored in the reference data area 21a matches the image data stored in the buffer area 21b, step 52 becomes YES, and the blue indicator lamp 13a is turned on in step 56. Let

The operator determines the mounting state of the sensor head 7 based on the lighting states of the indicator lamps 13a, 13b, and 13c. When at least the red indicator lamp 13c is lit, the sensor head is turned on so that the blue indicator lamp 13a is lit. Adjust the direction of 7 (parallelism and inclination) and the gap to perform the installation work.

On the other hand, since the sensor head 7 is detachably attached to the moving body 1 even during normal operation of the moving body 1, the sensor head 7 is caused by vibration accompanying the movement of the moving body 1 or wear of the guide rail. Misalignment may occur. Even during the normal operation, the image data from the image sensor 9 is read in step 51, compared with the first to third reference image data, and the corresponding indicator lamps 13a, 13b, and 13c are selectively turned on. Display.

For this reason, the operator can know the mounting position state of the sensor head 7 by the lighting state of the instruction lamps 13a, 13b, and 13c. When at least the red indicator lamp 13c is lit, the movement of the moving body 1 is stopped, and the direction and gap of the sensor head 7 are adjusted so that the blue indicator lamp 13a is lit. Return to.

During normal operation, when dust adheres or the characteristics of the image sensor 9 deteriorate, the detection voltage output from the image sensor 9 decreases and image data cannot be generated. Even in this case, it is possible to control the lighting of the instruction lamps 13a to 13c to check the dust adhesion state and the characteristic deterioration state, and to perform the position detection work efficiently.

In the present embodiment, when the sensor head 7 is attached, the sensor head 7 can be easily attached in a normal state by performing an attachment operation so that the blue indicator lamp 13a is lit. Further, during normal operation, the position deviation can be easily recognized by lighting the yellow or red indicator lamps 13b and 13c, and the blue indicator lamp 13a is also lit in the adjustment operation. Thus, the normal state can be restored, and the adjustment work can be performed easily and efficiently.

  The first embodiment is an optical position detection device, but the second embodiment is configured as a magnetic position detection device. That is, as shown in FIG. 7, the detected object is configured as a field scale 81 in which N poles and S poles of a predetermined width are alternately magnetized, and a plurality of sensors for detecting the magnetism of the detected object in the sensor head 7. A magnetic detection member 83 in which Hall elements and the like are arranged in the longitudinal direction of the detection object is provided, and the magnetic detection member 83 detects the magnetism of the detection object and outputs position data as the moving body moves. The

In the case of the magnetic type, if the sensor head 7 is attached in a normal state to the object to be detected, a magnetic neutral point that is the boundary between the N pole and the S pole always appears as a magnetic detection signal. When the sensor head 7 is attached to the body at an inclination, the magnetic neutral point does not appear. Further, when the interval between the magnetic detection member 83 and the field scale 81 is widened, the magnetic force is attenuated by the square of the distance, and the magnetic detection signal is extremely lowered to be below the threshold value.

In the present embodiment, when the sensor head 7 is mounted in a normal state, data based on the signal from the magnetic detection member 83 is the first reference image data, and the second is a normal range that is not normal but does not require position adjustment. The reference image data, the third reference image data when the mounting position is not completely in a normal state, the data based on the signal output from the magnetic detection member 83 when the sensor head 7 is attached to the moving body 1 or during normal operation, and the above-described data The first to third reference data are compared to diagnose the mounting state of the center head, and the indicator lamps 13a, 13b, 13c corresponding to the respective diagnosis results are selectively turned on to attach the sensor head 7 to the operator. Display status.

Further, during normal operation, the operator can know the mounting state of the sensor head 7 from the lighting state of the respective indicator lamps 13a, 13b, and 13c, and the yellow or red indicator lamps 13b and 13c are lit to cause misalignment. In this case, adjustment may be made so that the blue indicator lamp 13a is lit.

  In the first and second embodiments described above, the image sensor 9 is mounted on the sensor head 7, and an optical and magnetic position detection device that diagnoses and displays a misalignment state based on image data from the image sensor 9 is provided. However, the present embodiment relates to a method for diagnosing and displaying the mounting position state of the sensor head based on an electrical signal from a light receiving member such as a photodiode.

  As shown in FIG. 8, a light irradiation unit 11 is attached to one arm 90b of the sensor head 90, and a light receiving member 91 such as one photodiode is attached to the other arm 90a, and the light receiving member 91 receives light. An electrical signal with a voltage corresponding to the amount is output. Specifically, each light receiving member 91 outputs a sin waveform electrical signal from the A phase and a cos waveform electrical signal from the B phase. These electric signals are voltages according to the interval (gap) with the timing fence 93 described later, and the sin waveform and the cos waveform are curves according to the inclination of the light receiving member 91 with respect to the timing fence 93.

Further, the timing fence 93 as a detected body that extends in the moving direction of the moving body 1 between the light irradiation section 11 and the light receiving member 91 and in which the light transmitting sections 93a and the light blocking sections 93b having a predetermined width are alternately arranged. Are provided so as to coincide with the moving direction of the moving body. About another structure, it is the same as that of Example 1 and 2, and attaches | subjects the same code | symbol and abbreviate | omits detailed description.

  Now, the sensor head 90 is in a normal state with respect to the moving body 1, that is, the light receiving member 91 is at a normal interval between the light irradiation unit 11 and the light receiving member 91 with respect to the timing fence 93, and the sensor head 90 is in the longitudinal direction. When the moving body 1 moves, each light receiving member 91 outputs a reference sin and cos curve electric signal with a predetermined reference voltage value.

On the other hand, when the sensor head 90 is displaced (tilted) with respect to the timing fence 93, the curvature of the sin and cos curves of the electric signal output from the light receiving member 91 becomes the above-mentioned reference sin and cos. When the curve and the curvature are different and the interval of the light receiving member 91 with respect to the timing fence 93 is displaced, an electrical signal having a voltage equal to or higher than the reference voltage value is output.

  Then, the control means stores the electric signal output from each light receiving member 91 and A / D converted in the buffer area 21b, and then compares the reference voltage with the reference sin and cos curves, and these are set in advance. If it is within the predetermined range, it is diagnosed that the sensor head 90 is attached to the moving body 1 in the above-described normal state, and the blue indicator lamp 13a is displayed. If the sensor head 90 is slightly displaced from the sin and cos curves, the sensor head 90 is displaced with respect to the moving body 1, but it is diagnosed that it is within the range that does not need to be corrected, and the yellow indicator lamp 13b In addition, when these are largely displaced from the preset reference voltage and the reference sin and cos curves, it is diagnosed that the sensor head 90 is completely displaced with respect to the moving body 1. Red Selectively lighting the indication lamp 13c of. (See Figure 9)

For this reason, when the operator attaches the sensor head 90 to the moving body 1, the sensor head 90 may be attached while adjusting the position so that the blue indicator lamp 13a is lit. Even in such a case, the sensor head 90 can be mounted in a normal state in a short time so that the blue indicator lamp 13a is lit. Further, during normal operation, the operator can check the mounting position of the sensor head 90 by lighting the instruction lamps 13a, 13b, and 13c. The position of the indicator lamp 13a can be adjusted so that the indicator lamp 13a is lit and the normal mounting state can be restored.

During normal operation, when dust adheres or the characteristics of the light irradiation unit 11 and the light detection member 91 deteriorate, the detection voltage output from the light detection member 91 decreases to generate image data. become unable. Even in this case, it is possible to control the lighting of the instruction lamps 13a to 13c to check the dust adhesion state and the characteristic deterioration state, and to perform the position detection work efficiently.

In the third embodiment, the electrical signals of the respective light receiving members 91a to 91d are analog-processed and the respective indicator lamps are selectively turned on to enable the diagnostic display of the mounting position. However, each of the light receiving members 91a to 91c can be displayed. Each of the indicator lamps may be selectively lit and displayed by digitally processing the electrical signal by A / D conversion.

  In the above description, the sensor head mounting state is optically detected and displayed in the same manner as in the first embodiment. However, as in the second embodiment, the mounting state may be displayed in a magnetic detection format.

  The above description uses three indicator lamps to indicate the mounting position of the sensor head 90, and displays the mutual distance between the light receiving members 91 with respect to the timing fence 93 and the tilt state of the sensor head 90 with respect to the timing fence 93 in common. However, it may be a method of displaying each attachment state individually.

1. In the above description, the use of the three indicator lamps 13a, 13b, and 13c is used to indicate whether or not the mounting state is appropriate. However, four or more indicator lamps that are display means are provided and the reference data area indicates the mounting position state. Each reference data detailing the deviation may be stored, and each indicator lamp may be selectively or combined to control lighting so that details of the mounting position state can be displayed. When four indicator lamps are used and are lit in combination, 4-bit information can be displayed.

2. In the above description, the scale 5 having a length substantially the same as the moving distance of the moving body is used as the detected body, and the position detecting device that detects the moving position of the moving body that moves linearly has been described. Sensors are used to detect the rotational position of the moving body by detecting the rotational position of the moving body by alternately providing light transmitting sections and light blocking sections in the circumferential direction, or using a field disk with N and S poles alternately magnetized in the circumferential direction. The head mounting position state may be detected and displayed.

3. In the above description, at least three indicator lamps are used as the display means. However, the display means of the present invention may be an indicator-type display means in which the light display unit is displaced according to the degree of displacement. Further, the display means may be a display panel that displays character information corresponding to the misalignment state.

It is explanatory drawing which shows the moving mechanism to which the attachment position warning method and attachment position correction method of a position detection apparatus are applied. It is explanatory drawing which shows the outline of a position detection apparatus. It is an electrical block diagram which shows the control outline. It is explanatory drawing which shows the image data when a sensor head is attached in a regular state. It is explanatory drawing which shows the image data when a sensor head has shifted position. It is a flowchart which shows the position adjustment process at the time of attaching a sensor head. FIG. 6 is an explanatory diagram illustrating an example of a magnetic position detection device according to a second embodiment. It is explanatory drawing which shows the example of a position detection apparatus by the light-receiving member based on Example 3. FIG. 10 is a flowchart illustrating attachment position state diagnosis processing according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1- Moving body, 5-Scale as a to-be-detected body, 7- Sensor head, 9- Image sensor as a detection part, 13a * 13b * 13c-Indicating lamp, 21a-Reference data area as a memory | storage part

Claims (8)

A sensor head provided with a plurality of detectors detachably attached to the moving body and arranged in accordance with the moving direction thereof, and a target having a large number of detected parts arranged along the moving direction of the moving body. In the position detection device that detects the moving position of the moving body by the detection body, a signal output from each detection unit when the sensor head is attached to the detection target in a normal state is used as a reference value. A position detection device for displaying and controlling display means for diagnosing the mounting state of the sensor head with respect to the moving body by comparing a signal output from the detection unit with a reference value and displaying the diagnosis result in at least three stages. Status diagnosis display method. The sensor head according to claims 1 and 2 is configured such that the object to be detected is configured by alternately arranging the light transmitting part and the light blocking part, and the detecting part is formed from the light irradiation part and the light receiving part facing each other with the object to be detected interposed therebetween. A mounting state diagnosis display method for a position detecting device. The light receiving unit according to claim 2, wherein the position detecting device is a display state diagnosis display method comprising any one of a photodiode and a CCD. The sensor head according to claim 1, wherein the detection object is a field body in which different magnetic poles are alternately arranged, and the detection unit is configured by a magnetic detector. The display means of claim 1 comprises at least three light emitting members that irradiate different light, and an attachment state diagnosis display for a position detection device that emits light from the light emitting member in multiple stages according to the attachment state of the sensor head to the detected object. Method. The display means according to claim 1 is an attachment state diagnosis display method of a position detection device comprising display means for displaying diagnosis information of the attachment position state of the sensor head with respect to the detected object. The moving body according to claim 1 is an attachment state diagnosis display method for a position detecting device that moves linearly. The moving body according to claim 1 is an attachment state diagnosis display method for a position detector that rotates.

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