JP2009128062A - Electronic control system and rotary encoder used for this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic control system which enables safe operation of a system on the electronic control unit side. <P>SOLUTION: Two A and B phase circuits, Main and Sub, are provided on the rotary encoder 11 side and an output of the main A and B phase circuit is outputted to a system control part SC of an electronic control unit 13, while an output of the sub A and B phase circuit is outputted to each of both system and backup control parts SC and BC. On the other hand, normality and abnormality of the two A and B phase circuits are self-diagnosed and the results of the self-diagnosis are outputted as fail-safe signals to both of the system and backup control parts on the electronic control unit side, in the constitution of this electronic control system. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a rotary encoder that generates and outputs an A-phase signal and a B-phase signal as the detected shaft rotates, and an electronic control device that controls the rotational operation of the detected shaft based on both the A and B-phase signals. The present invention relates to an electronic control system provided with a rotary encoder and a rotary encoder used therefor.

  For example, an electronic control system that electronically controls an elevator apparatus will be described with reference to FIG. 7. The elevator apparatus 1 drives the hoisting machine 3 with a drive motor 5 and moves the car 9 up and down via a rope 7. Then, both A and B phase signals, which are detection signals from the rotary encoder 11 attached to the motor shaft 10 of the drive motor 5 that is the detected shaft, are input to the electronic control device 13 (see, for example, Patent Document 1). The electronic control device 13 has a built-in microcomputer, and drives and controls the drive motor 5 by a detection signal from the rotary encoder 11. There are various other details of elevator control by the electronic control unit 13, but the description thereof is omitted.

  In the above electronic control system, in addition to the system control unit that controls the rotation operation of the detected shaft on the electronic control device 13 side based on both the A and B phase signals, the A, In some cases, a backup control unit that performs backup control of the rotation operation of the detected shaft based on both B-phase signals may be provided. In this case, when the microcomputer is mounted not only on the system control unit but also on the backup control unit, the rotary encoder 11 also corresponds to the electronic control unit 13. Will be required.

  As shown in FIG. 8, the rotary encoder 11 generally transmits light from the light projecting element LED at equal intervals in the circumferential direction between the light projecting element LED and the two light receiving elements PD1 and PD2. A rotary slit plate RS having a plurality of slits (hereinafter referred to as rotary slits), and a slit (hereinafter referred to as light transmitting element LED) that can transmit light from one of the rotary slit plates RS in the same manner as the slits. A fixed slit plate FS having a fixed slit) is disposed oppositely.

  The fixed slit of the fixed slit plate FS shifts the light from the light projecting element LED by 90 degrees sequentially in electrical angle and passes through the rotary slit of the rotary slit plate RS to form an optical signal.

  As shown in FIG. 9, the light receiving elements PD1 and PD2 receive the optical signal as a detection unit, and the light reception outputs of the light receiving elements PD1 and PD2 are compared with a reference voltage by comparison circuits CP1 and CP2 as signal generation units. Thus, the A-phase signal that is inverted every 180 degrees and the B-phase signal that is 90 degrees out of phase from the A-phase signal and inverted every 180 degrees are generated and output from the comparison circuits CP1 and CP2, respectively. Both the A and B phase signals are input to the electronic control unit 13 via the. The electronic control unit 13 can detect the rotation state of the detected shaft, that is, the rotation direction and the rotation speed from both the A and B phase signals.

In such a rotary encoder 11, even if a microcomputer is mounted on both the system control unit and the backup control unit on the electronic control device 13 side to achieve safety as an electronic control system, the basis of the safety is provided. If there is an abnormality or the like on the rotary encoder 11 side, the safety may be easily lost. Therefore, in order to further improve the safety of the electronic control system, the applicant of the present application has made an eager study to add a self-diagnosis function to the rotary encoder 11.
Japanese Patent Laid-Open No. 07-134048

  The problem to be solved by the present invention is to provide an electronic control system that enables an electronic control device to safely perform system operation by a rotary encoder output, and a rotary encoder used therefor.

  An electronic control system according to the present invention controls a rotary encoder that generates and outputs an A-phase signal and a B-phase signal as the detected shaft rotates, and controls the rotational operation of the detected shaft based on both the A- and B-phase signals. In an electronic control system including an electronic control device, a main and sub two A and B phase circuits for outputting both the A and B phase signals are provided on the rotary encoder side, respectively, while a microcomputer is provided on the electronic control device side. Built-in system control unit and backup control unit are provided to be able to monitor each other, main A and B phase circuit output to the system control unit of the electronic control device, sub A and B phase circuit output to the system and backup both control unit, respectively On the other hand, the rotary encoder side performs self-diagnosis on the normality and abnormality of both A and B phase circuits, and the self-diagnosis result is used as a fail-safe signal. Is characterized in that the output to the system and the backup both controller of the control apparatus side.

  In the present invention, two main and sub A and B phase circuits are provided on the rotary encoder side, the main A and B phase circuit outputs are supplied to the system controller of the electronic control unit, and the sub A and B phase circuit outputs are supplied to both the system and the backup. While outputting to the control unit respectively, normality and abnormality of both A and B phase circuits are self-diagnosed, and the self-diagnosis result is output as a fail-safe signal to both the system and backup control unit on the electronic control unit side Therefore, on the electronic control device side, a microcomputer can be mounted on both the system and the backup control unit to achieve safety as an electronic control system, while on the rotary encoder side which is the basis of the safety, both main and sub A Even if an abnormality or the like exists in one of the B phase circuits, it is possible to maintain safety by inputting both the A and B phase signals from the other side to the electronic control device side. Come, it is possible to achieve further safety of the entire electronic control system.

  In addition, when a fail-safe signal is output from the rotary encoder side to the electronic control unit side due to the above failure, the electronic control unit side does not need to immediately stop the system operation by inputting the fail-safe signal, and the system operation is not performed. It can be done safely. In addition, when the main A / B phase circuit is switched from the main A / B phase circuit to the sub A / B phase circuit on the rotary encoder side, a failure or the like exists in the main A / B phase circuit. On the other hand, maintenance can be performed to eliminate the cause of failure.

  In the present invention, when the system control and the backup control unit on the electronic control device side are intended to improve the safety of system operation, even if there is an abnormality in the main A or B phase circuit on the rotary encoder side, the electronic control device side It becomes possible to continue system operation safely.

  Hereinafter, an electronic control system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the embodiment, the present invention is applied to an electronic control system that controls an elevator, but the present invention can also be applied to other electronic control systems.

  The schematic configuration of the electronic control system will be described with reference to FIG. 1. The rotary encoder 11 includes a main A and B phase circuit Main, a sub A and B phase circuit Sub, and a microcomputer MC. The electronic control device 13 includes a system control unit SC and a backup control unit BC.

  In the rotary encoder 11, both the main and sub A and B phase circuits Main and Sub generate and output both A and B phase signals, respectively. The microcomputer MC determines whether the A and B phase circuits Main and Sub are normal from the A and B phase circuits Main and Sub outputs by self-diagnosis, and uses the determination output as a fail-safe signal for backup with the system controller SC. Output to the controller BC.

  In the electronic control unit 13, the system control unit SC includes a microcomputer (not shown) and is driven based on both A and B phase signals from one of the main and sub A and B phase circuits Main and Sub. System control of the rotational operation of the motor 5 is performed. The backup control unit BC incorporates a microcomputer (not shown) and is based on both the A and B phase signals from the sub A and B phase circuits Sub when the system control unit SC is down. Thus, backup control of the rotation operation of the drive motor 5 is performed. Both control units SC and BC monitor the state of the rotary encoder 11 by a fail-safe signal from the rotary encoder 11, and when the system control unit SC goes down, the backup control unit BC is sub-A, and A from the B-phase circuit Sub. The rotational operation of the drive motor 5 is backed up based on both the B-phase signals. The system control unit SC and the backup control unit BC can communicate with each other by a built-in microcomputer, and the backup control unit BC monitors whether the system control unit SC is down.

  Referring to FIG. 2, the rotary encoder 11 includes a single light projecting element LED, a single fixed slit plate FS, and a single rotary slit plate RS. The light emitting element LED is inserted and connected in series with the current limiting resistor R0 and the transistor TR0 between the power source and the ground, and performs a light projecting operation through a transistor TR0 that is turned on / off by a control output of the microcomputer MC described later.

  Further, the main A and B phase circuits Main emit light from the light projecting element LED via the rotary slit plate RS and the fixed slit plate FS, and the light receiving elements PD1 (a +), PD1 (a−), PD1 (b +). ), PD1 (b−). The outputs of these light receiving elements PD1 (a +), PD1 (a−), PD1 (b +), PD1 (b−), are compared by the comparison circuits CP1 and CP2, and the main A-phase signal ( A) The main B-phase signal (B) is output from the comparison circuit CP2 to the electronic control unit 13 via the output circuit unit RD1, and the main A-phase signal and the main B-phase signal are the microcomputer MC serving as control means. Is input.

  Similarly, the sub-A and B-phase circuits Sub receive light from the light projecting element LED through the rotary slit plate RS and the fixed slit plate FS, and the light receiving elements PD2 (a +), PD2 (a−), PD2 (b +). , PD2 (b−). The outputs of these light receiving elements PD2 (a +), PD2 (a−), PD2 (b +), and PD2 (b−) are compared by the comparison circuits CP3 and CP4, and the main A-phase signal ( A) The main B-phase signal (B) is output to the electronic control unit 13 via the output circuit unit RD2, and the main A-phase signal and the main B-phase signal are input to the microcomputer MC as control means.

  The microcomputer MC determines whether the main and sub A and B phase signals from the main A and B phase circuits Main and the sub A and B phase circuits Sub are normal and abnormal, respectively. Output a signal.

  A mechanical configuration of the rotary encoder 11 according to the embodiment will be described with reference to FIGS. In FIG. 3, the light emitting element LED, the fixed slit plate FS, the rotary slit plate RS, the light receiving element PD1 (a +), PD1 (a−), PD1 (b +), PD1 (b−), PD2 (a +), PD2 (a −), PD2 (b +), PD2 (b−). The light projection from the light projecting element LED is received by each light receiving element via the fixed slit plate FS and the rotary slit plate RS.

  FIG. 4A shows the configuration corresponding to the main A and B phase circuit Main, and FIG. 4B shows the configuration corresponding to the sub A and B phase circuit Sub, but the rotation shown in FIG. 4A and FIG. 4B respectively. The slit plate RS and the fixed slit plate FS may be the same. For convenience of illustration, the slit plate RS and the fixed slit plate FS are shown separately in FIGS. 4 (a) and 4 (b).

  4 (a) and 4 (b), rs are rotating slits formed in the rotating slit plate RS at equal intervals in the circumferential direction. In the drawing, in the rotary slit plate RS, the portion of the rotary slit rs is white in the illustration, and the portion between the rotary slits rs is a portion that blocks light projection of the light projecting element LED, and is indicated by hatching in the illustration. The fixed slit plate FS has a fixed slit fs opposed to the rotating slit rs.

  For convenience of explanation, the fixed slit fs is fs (a +) which generates the optical signal a + that inverts the light of the light projecting element LED every 180 degrees, and the electrical angle is shifted 180 degrees from the optical signal a + by 180 degrees. The fixed slit for generating the optical signal a− that is inverted every degree is fs (a−), and the light of the light projecting element LED is shifted by 90 degrees in electrical angle from the optical signal a +, and the optical signal b + that is inverted every 180 degrees is generated. The fixed slit is referred to as fs (b +), and the fixed slit that generates the optical signal b− that is shifted by 180 ° in electrical angle with respect to the optical signal b + and is inverted every 180 ° is referred to as fs (b−). The fixed slit fs uses common reference symbols for the light receiving elements of the main A, B phase circuit Main, sub A, and B phase circuit Sub in order to avoid complication of explanation and illustration.

  The light receiving elements of the main A, B phase circuit Main and the sub A, B phase circuit Sub are also PD1 in accordance with the respective fixed slits fs (a +), fs (a−), fs (b +), fs (b−). (A +), PD1 (a−), PD1 (b +), PD1 (b−), PD2 (a +), PD2 (a−), PD2 (b +), PD2 (b−) The elements PD1 (a +), PD1 (a−), PD1 (b +), PD1 (b−), PD2 (a +), PD2 (a−), PD2 (b +), and PD2 (b−) have corresponding fixed slits. The optical signals a +, a−, b +, b− that have passed through fs (a +), fs (a−), fs (b +), and fs (b−) are received.

  In the main A and B phase circuit Main, the outputs of the light receiving elements PD1 (a +) and PD1 (a−) receiving the optical signals a + and a− are compared by the comparison circuit CP1 as described above, and the A phase signal is obtained. The outputs of the light receiving elements PD1 (b +) and PD1 (b−) that are generated and receive the optical signals b + and b−, respectively, are compared by the comparison circuit CP2 as described above to generate a B phase signal.

  In the sub A and B phase circuit Sub, the outputs of the light receiving elements PD2 (a +) and PD2 (a−) that receive the optical signals a + and a−, respectively, are compared by the comparison circuit CP3 as described above, and the A phase signal is obtained. The outputs of the light receiving elements PD2 (b +) and PD2 (b−) that are generated and receive the optical signals b + and b−, respectively, are compared by the comparison circuit CP4 as described above to generate a B phase signal.

  Referring to FIGS. 5A to 5C, the A phase signal and the B phase signal of each of the main A, B phase circuit Main, sub A, and B phase circuit Sub are output in the output circuit sections RD1 and RD2, respectively. a) and converted into the digital A-phase signal and B-phase signal shown in FIG. In binary code, A phase signal is “0”, B phase signal is “0”, “0”, A phase signal is “1”, B phase signal is “0”, “2”, A phase signal Is “1” and the phase B signal is “1”, the timing is “3”, the phase A signal is “0”, and the phase B signal is “1”. The timing is “0”, “2”, “ In the order of “3” and “1”, as described in the background art, it is possible to detect and determine that the rotation direction is one side, for example, clockwise, and in the reverse order, counterclockwise. Further, the rotational speed can be detected by counting the number per unit time such as the A phase signal.

  The microcomputer MC inputs the A phase signal and the B phase signal from the main A and B phase circuits Main and the sub A and B phase circuits Sub, respectively. And a fail-safe signal corresponding to the determination is output.

  Referring to FIG. 6, the microcomputer MC of the rotary encoder 11 will be described. The microcomputer MC includes a phase signal input unit M1, a light projecting element drive unit M2, a fail safe signal output unit M3, a CPU M4, And a memory M5. These are interconnected by an internal bus M6.

  In the microcomputer MC, the phase signal input unit M1 inputs and processes the A phase signal and the B phase signal of each of the main A and B phase circuits Main and the sub A and B phase circuits Sub. The light projecting element driving unit M2 outputs a driving signal to the transistor TR0. The fail safe signal output unit M3 outputs a fail safe signal to the electronic control device 13 when the rotary encoder 11 is abnormal in operation. The electronic control device 13 ensures the safety of the electronic control system by controlling the rotation of the driving motor 5 to the safe side in response to the fail safe signal.

  The memory M5 includes various memories such as a flash memory, a mask ROM, and a RAM. The memory M5 stores an execution program for the CPU M4 to execute the operation of the entire rotary encoder 11, an operation abnormality determination program for the CPU M4 to perform an operation abnormality determination, and other programs.

  The CPU M4 constitutes detection means for detecting whether the A phase signal and the B phase signal have failed. For example, the CPU M4 and the fail-safe signal output unit M3 set the fail-safe signal to “00”, sub-A, B when the A-phase of the main A and B-phase circuit Main is abnormal among the phases of the A and B phase signals. When the phase A of the phase circuit Sub is abnormal, the fail safe signal is output as “01” to the electronic control device 13 side. When the phase B of the main A and B phase circuits Main is abnormal, the fail safe signal is set to “10”. When the B phase of the sub A, B phase circuit Sub is abnormal, the fail safe signal is output to the electronic control device 13 side as “11”. In the electronic control unit 13, it is possible to grasp whether the A phase or B phase of the main A, B phase circuit Main or sub A, B phase circuit Sub is abnormal from the value of the fail safe signal.

  In the embodiment, the CPU M4 performs self-diagnosis as to whether or not the abnormality is present, but other abnormal forms may be included.

  As described above, in the embodiment, the electronic control device 13 side controls the rotation operation of the drive motor 5 based on both the A and B phase signals from the main A and B phase circuits Main by the system control unit SC. If there is an abnormality in the main A / B phase circuit Main during the process, the abnormality can be detected by the fail-safe signal. Therefore, sub A, B from the input of both the A and B phase signals from the main A / B phase circuit Main. Switching to the input of both A and B phase signals from the phase circuit Sub is performed to control the rotation operation of the drive motor 5. When the system control unit SC goes down, the electronic control unit 13 switches to the backup control unit BC, and the backup control unit BC performs backup control using both the A and B phase signals from the sub A and B phase circuits Sub. be able to. In this case, if the sub-A and B-phase circuit Sub is abnormal due to the fail-safe signal, the backup control can be stopped and maintenance can be performed.

FIG. 1 is a diagram showing a schematic configuration of an electronic control system according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic electrical configuration of the rotary encoder according to the embodiment of the present invention. FIG. 3 is a diagram for explaining the correspondence between the light projecting element, the rotating slit, the fixed slit, and the light receiving element. FIG. 4 is an enlarged plan view showing a main part of FIG. FIG. 5 is a diagram showing an A phase signal, a B phase signal, and others. FIG. 6 is a block diagram showing a microcomputer, an electronic control unit (ECU), and a drive motor of the rotary encoder according to the embodiment. FIG. 7 is a diagram showing an elevator apparatus, a rotary encoder, and an electronic control apparatus. FIG. 8 is a view showing a schematic mechanical configuration of a conventional rotary encoder. FIG. 9 is a diagram showing a schematic electrical configuration of a conventional rotary encoder.

Explanation of symbols

11 Rotary encoder 13 Electronic control device PD Light receiving element MC Microcomputer (control means)

Claims (3)

An electronic device comprising: a rotary encoder that generates and outputs an A-phase signal and a B-phase signal as the detected shaft rotates; and an electronic control device that controls the rotational operation of the detected shaft based on both the A and B-phase signals. In the control system,
On the rotary encoder side, there are two main and sub A and B phase circuits that output both the A and B phase signals. On the electronic control unit side, the microcomputer control system and the backup controller are mutually monitored. The main A and B phase circuit outputs are output to the system control unit of the electronic control unit, and the sub A and B phase circuit outputs are output to both control units, respectively, while the rotary encoder side has both the A and B phase circuits. An electronic control system characterized in that self-diagnosis is performed for normality and abnormality, and a fail-safe signal as a result of the self-diagnosis is output to both control units on the electronic control device side.   The rotary encoder is provided with a microcomputer that performs self-diagnosis of both the A and B phase circuits and outputs a fail-safe signal as a result of the diagnosis to the electronic control unit side. The electronic control system according to claim 1.   In a rotary encoder that generates and outputs an A-phase signal and a B-phase signal as the detected shaft rotates, at least two A and B phase circuits that generate both the A and B phase signals, A microcomputer that performs self-diagnosis of normal and abnormal B-phase circuits and outputs a fail-safe signal as a result of the diagnosis is used, and is used in the electronic control system according to claim 1. Rotary encoder.

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