JP4273933B2 - Rotary encoder - Google Patents

Description

  The present invention relates to the reliability of the basic components of a rotary encoder that detects the rotational position of a rotating body. In particular, the present invention is used by being incorporated in a servo motor, and the rotational position information and abnormality information of the rotating body by bidirectional serial communication means. Is to communicate.

  In recent years, with the increase in reliability of industrial equipment, there is an increasing demand for high reliability such as fault diagnosis for a rotary encoder built in a servo motor that is incorporated in the equipment and used.

Under such circumstances, a temperature sensor is provided in the motor winding and encoder, and the presence or absence of winding abnormality or encoder data abnormality is determined by measuring the temperature during actual operation (see, for example, Patent Document 1). .)
JP 07-43177 A

  The problem to be solved is that even if it is possible to instantly determine whether or not a component is within the guaranteed operating temperature range, it can operate for long-term deterioration in a high-temperature environment where performance is likely to deteriorate. Even within the temperature range, the judgment cannot be made.

  In particular, an object of the present invention is to provide a rotary encoder capable of easily and accurately diagnosing a failure of a core part whose deterioration with time varies depending on an operating temperature among encoder components.

  In order to solve the above problems, a rotary encoder according to the present invention includes an original signal unit that outputs rotational position data in accordance with rotation, a temperature detection unit that detects an operating temperature of the original signal unit, and the original signal unit. A timer unit that measures the operating time, an electrically writable storage unit that updates and holds time data measured by the timer unit, and an integration order according to the operating temperature detected by the temperature detection unit. A selection unit, an addition unit for adding the time data of the timer unit newly measured to the previous time data held in the storage unit, operation / stop timing of the timer unit, and rewriting timing of the time data in the storage unit The power ON / OFF detection unit to output and the serial signal which is a request signal from the outside are received, and the data corresponding to the request signal is obtained from the data of the original signal unit and the storage unit A selection unit provided between the temperature detection unit and the timer unit is detected by the timer operation setting parameter stored in the storage unit and the temperature detection unit. The timer unit measures the operating time based on the selected integration order, and the addition unit integrates the previous time data and the newly measured timer unit time data for each integration order. The storage unit holds the accumulated time data.

  Further, an integration coefficient weighted according to the operating temperature is used for the integration order.

  Furthermore, the integration coefficient is obtained by parameterizing the deterioration coefficient with time of the light emitting element, which is a basic part of the original signal portion, for each operating temperature range.

In the rotary encoder of the present invention, the operation time data is integrated and stored in the storage unit for each integration order corresponding to the operation temperature detected by the temperature detection unit, and the life and life expectancy of key parts can be easily and accurately diagnosed. Analysis is possible.

  Further, by using the integration coefficient, it is possible to replace the actual operation time with the apparent total operation time at room temperature, thereby facilitating diagnosis and analysis of basic parts.

  Furthermore, it is possible to directly diagnose a specific component that is greatly deteriorated with time depending on the operating temperature.

  An original signal unit that outputs rotational position data according to rotation, a temperature detection unit that detects an operating temperature of the original signal unit, a timer unit that measures a time during which the original signal unit is operating, and the timer unit An electrically writable storage unit that updates and holds the time data measured in step 1, a selection unit that switches to an integration order corresponding to the operating temperature detected by the temperature detection unit, and the previous time data stored in the storage unit Adder for adding time data of timer unit newly measured, power ON / OFF detection unit for outputting operation / stop timing of timer unit and rewriting timing of time data in storage unit, request signal from outside A data communication unit that receives the serial signal and selects the data corresponding to the request signal from the data of the original signal unit and the storage unit, converts the data into serial data, and outputs the data. The selection unit provided between the temperature detection unit and the timer unit selects an integration order from the timer operation setting parameter held in the storage unit and the temperature detected by the temperature detection unit, and the timer unit is selected. The operation time is measured based on the integration rank, and the storage unit accumulates and stores the measured time data for each integration rank.

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

  FIG. 1 is a configuration diagram of a rotary encoder. An original signal unit 11 outputs rotational position data corresponding to the rotation of a motor. The temperature detector 12 measures and outputs the surface temperature or ambient temperature of the circuit board of the original signal unit 11. The timer unit 13 measures the time during which the original signal unit 11 is operating. The storage unit 14 is an EEPROM that is an electrically rewritable and erasable storage element that holds the time data measured by the timer unit 13, and the timer operation setting parameter in which the operation temperature range and integration order are parameterized in the storage unit 14. Is held. The selection unit 15 selects and switches the integration order from the timer operation setting parameters according to the operating temperature of the temperature detection unit 12. The adding unit 16 adds the current time data measured by the timer unit 13 to the previous time data held in the storage unit 14. The ON / OFF signal of the power ON / OFF detection unit 17 is used for the operation / stop timing of the timer unit 13 and the data rewrite timing in the storage unit 14. The data communication unit 18 receives a serial signal which is a request signal from the outside, selects data corresponding to the request signal from the data in the original signal unit 11 and the storage unit 14, converts it into serial data, and outputs it.

FIG. 2 illustrates the operation of the original signal unit 11 and is data of 0 to 2 ^m −1 in monotone increase at CCW rotation and monotone decrease at CW rotation at an absolute position within 360 ° of one rotation at a resolution of mbit. One rotation data and the number of rotations of the motor are output, and multi-rotation data which is an increase change during CCW rotation and a decrease change during CW rotation is output.

  FIG. 3 shows an internal configuration of the data communication unit 18, and a bidirectional bus 31 composed of a line driver receiver switches between transmission and reception of serial data with the outside. The receiver 32 receives a serial signal, which is a request signal from the outside, and generates a command indicating the request content. The selector 33 selects data according to a command generated from the request signal from the data of the original signal unit 11 and the storage unit 14. The transmitter 34 converts the command, the data selected by the selector 33, and the communication error detection data generated from the command and the selected data into serial data.

  FIG. 4 illustrates the configuration of serial data. The RX signal, which is a request signal to the encoder from the outside corresponding to a servo amplifier, is composed of a command section indicating which data in the encoder is selected, while the encoder The TX signal, which is a transmission signal from the outside to the outside, includes the command part received by the encoder, a data part along the command part, a command part, and a transmission error detection data part generated from the data part.

  A description will be given of a first embodiment in which failure diagnosis can be performed against long-term deterioration of components under an operating environment.

  FIG. 5 shows a temporal deterioration characteristic of the light emission amount with respect to the operation time of the light emitting element as a component of the original signal portion 11. If the time when the light amount reaches 50% of the initial value when continuously used at the temperature Ta is defined as the life time L1, the life time L1 is reduced to the life time L3 if the temperature Ta rises to the temperature Tc.

  FIG. 6 is an explanatory diagram of the timer operation setting parameters stored in the storage unit 14. The timer operation setting parameters are, for example, five levels from the operating temperature range T1 to the operating temperature range T5 so as to satisfy the operating temperature range of the original signal unit 11. And the five stages of integration rank are stored in advance in the storage unit 14 as parameters for the five stages of operating temperature range. For convenience of explanation, the integration order has been described in five stages, but can be arbitrarily set according to the storage capacity of the storage unit.

  The selection unit 15 selects the integration rank from the timer operation setting parameters according to the operation temperature detected by the temperature detection unit 12, and the timer unit 13 measures the operation time for each selected integration rank. The ON / OFF timing of the timer unit 13 is determined by the power ON / OFF detection unit 17, and the operation of the timer unit 13 is an ON period.

  At the OFF timing of the power ON / OFF detection unit 17, the addition unit 16 reads the time data for each previous integration rank stored in the storage unit 14 to the time data for each current integration rank measured by the timer unit 13. Add and store in the storage unit 14 and hold. Accordingly, the storage unit 14 holds time data for each new integration rank.

  That is, it is possible to easily grasp how many hours each component of the original signal unit has operated under what order (ie, operating temperature range), and can be used for diagnosis of lifespan and life expectancy. Further, since the operation time is integrated for each integration order, it can be used for general purposes even if the coefficient of deterioration with time is different depending on the operation temperature of the basic part. Therefore, the present invention can also be applied to electrolytic capacitors other than light emitting elements, electric double layer capacitors, and the like.

  In the second embodiment, the weighted integration coefficient due to the deterioration with time due to the operating temperature is used for the integration order of the first embodiment. The acceleration of deterioration in the lifetime characteristic of the light emitting element described in the first embodiment, that is, the operating temperature is high. If this is the case, it is associated with the degree of deterioration in which the deterioration is accelerated and the life is shortened, and can be converted into an apparent total operation time at room temperature.

  FIG. 7 illustrates the operation timing of each unit, and shows the power supply voltage waveform to which the ON / OFF of the encoder power supply 71 is applied. The power ON / OFF signal 72 output from the power ON / OFF detection unit 17 is It is obtained by discriminating the rising and falling voltages of the encoder power supply 71 with “H / L” at a predetermined voltage threshold.

The ON signal 73 and the OFF signal 74 are obtained by detecting a rising change and a falling change of the power ON / OFF signal 72. In response to the ON signal 73, the timer unit 13 starts measuring the operating time. Further, the previous time data held in the storage unit 14 by the OFF signal 74 and the current time data are added by the adding unit 16 and held as new time data in the storage unit 14.

  The temperature data 75 shows an example of a temperature change during the operation of the original signal unit 11, and the temperature detected by the temperature detection unit 12 from the timer operation setting parameter held in the storage unit 14 in the selection unit 15. The integration coefficient 76 for the data is selected. The integration coefficient 76 corresponds to the integration order described with reference to FIG. 6, and a weighted coefficient is selected for each operating temperature range.

  The clock 77 (timer unit 13) starts to operate in response to the ON signal 73 and is output at a fixed period t. The clock 77 is integrated for each integration coefficient (D1 to D5 corresponding to the temperature range), and the current integration time data is used. A certain timer integrated value 78 is obtained. Then, the total operation time data A held in the storage unit 14 up to the previous time and the current timer integrated value 78 are added by the addition unit 16 at the timing of the OFF signal 74, and the total operation time as new time data is stored in the storage unit 14. 79 is overwritten and retained. The new total operation time 79 becomes the total operation time data A up to the previous time when the timer unit 13 starts the next operation.

  Therefore, it is possible to easily know the apparent operation time at room temperature from the time data held in the storage unit 14. Further, the total operation time 79 held in the storage unit 14 can be read out by a host machine to which the encoder is connected via the data communication unit 18.

  As an application example of the second embodiment, as in the first embodiment, the clock 77 is initially integrated for each integration rank, and the total operation time can be obtained by multiplying the integration coefficient at the stage of using this integrated value. . In this case, since only the time data for each integration rank is used, it can be used for basic parts having different coefficients of deterioration with time as in the first embodiment.

  As is clear from the first and second embodiments, the operation time is measured according to the operation temperature, and the operation time can be read even when the encoder alone or the servo motor incorporating the encoder is attached to the machine. It is possible to obtain a rotary encoder that can easily and accurately diagnose failure factors of core parts and diagnoses of parts life and remaining life.

  It can also be applied to applications where failure diagnosis of electronic parts and mechanical parts whose performance and reliability deteriorate with time due to operating temperature and improvement in maintainability of parts replacement are required.

The block diagram of the rotary encoder in embodiment of this invention Operation explanatory diagram of the original signal section in the embodiment of the present invention The block diagram of the data communication part in embodiment of this invention Explanatory drawing of signal structure of serial data in embodiment of this invention Explanatory drawing of the time-dependent deterioration characteristic of the light emitting element in Example 1 of this invention. Explanatory drawing of the timer operation | movement setting parameter in Example 1 of this invention. Explanatory drawing of the operation timing in Example 2 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Original signal part 12 Temperature detection part 13 Timer part 14 Memory | storage part 15 Selection part 16 Addition part 17 Power supply ON / OFF detection part 18 Data communication part

Claims (3)

An original signal unit that outputs rotational position data according to rotation, a temperature detection unit that detects an operating temperature of the original signal unit, a timer unit that measures a time during which the original signal unit is operating, and the timer unit An electrically writable storage unit that updates and holds the time data measured in step 1, a selection unit that switches to an integration order corresponding to the operating temperature detected by the temperature detection unit, and the previous time data stored in the storage unit Adder for adding time data of timer unit newly measured, power ON / OFF detection unit for outputting operation / stop timing of timer unit and rewriting timing of time data in storage unit, request signal from outside A data communication unit that receives the serial signal and selects the data corresponding to the request signal from the data of the original signal unit and the storage unit, converts the data into serial data, and outputs the data. The selection unit provided between the temperature detection unit and the timer unit selects an integration order from the timer operation setting parameter held in the storage unit and the temperature detected by the temperature detection unit, and the timer unit is selected. The operation time is measured based on the integration rank, the addition unit accumulates the previous time data and the newly measured time data of the timer unit for each integration rank, and the storage unit holds the accumulated time data. Rotary encoder. The rotary encoder according to claim 1, wherein an integration coefficient weighted according to the operating temperature is used for the integration order. The rotary encoder according to claim 2, wherein the integration coefficient is obtained by parameterizing the deterioration coefficient with time of a light emitting element that is a key component of the original signal section for each operating temperature range.

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