JP2000046585A - Encoder - Google Patents

Abstract

(57) [Summary] To provide an incremental encoder capable of reducing the number of wirings. SOLUTION: Position information and parameters are rewritten by bidirectional serial communication by an original signal output unit 101 that outputs an original signal of an encoder, a parameter storage circuit 103 of an encoder and a motor to be mounted, and a modem unit 104. be able to. It is possible to arbitrarily combine a one-to-one combination of a motor and a motor control device on the motor control device side, thereby eliminating the need for parameter setting and reducing the number of wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line-saving encoder for detecting a rotational position of a rotating body.

[0002]

2. Description of the Related Art A brushless DC servomotor and a brushless A servomotor are used for driving various machines.
There is a C servo motor (DC brushless servo motor), and in recent years, demand for an AC servo motor has been increasing due to ease of motor maintenance.

There are various types of position detectors for servo systems, and in recent years, encoders used by being incorporated in servo motors have become widespread. Encoders incorporated in AC servomotors are broadly classified into incremental encoders and absolute encoders. The incremental encoders are 90 degrees apart from each other so that the direction of rotation can be determined.
A and B signals having a phase difference, a reference Z signal of one pulse per rotation, and energized phases U, V and W of the AC servomotor.
It is common to have a commutation signal for phase switching. An absolute encoder is an encoder that can recognize the absolute position within one rotation immediately after turning on the power. The absolute position, which is the operation of aligning the machine position with the controller immediately after turning on the power required in a control system using an incremental encoder, is performed. Since a return operation is not required, it is widely used in servomotors for large robots such as articulated robots.

Hereinafter, the configuration of a conventional incremental encoder will be described. 4, reference numeral 401 denotes a light emitting element, 402 denotes a light receiving element, 403 denotes a rotating slit plate,
04 is a fixed slit plate, 405 is a waveform shaping circuit for shaping an analog output signal obtained by converting an optical signal into an electric signal by each segment of the light receiving element into a digital output signal, 406
Is a buffer circuit.

The encoder incorporated in the AC servomotor has two phase signals of A and B having a phase difference of 90 degrees as described above, a reference Z signal of one pulse per rotation, and an energization phase switching of the AC servomotor. A signal having commutation signals U, V, and W phases is generally used. When each signal is differentially output, the number of signal lines is 6 signals × 2 = 12 since two wires are provided for one signal, and when two power supply wires are added, a total of 14 lines is obtained. This is the number of wires.

[0006]

However, in the above conventional configuration, parameters such as the number of pulses and the number of poles of the encoder, the output of the motor to be mounted, the induced voltage constant, and the torque constant are manually controlled by the motor control device on the receiving side. It has to be set, and there is a problem that the number of product models increases because the motor and the motor control device are one-to-one.

Further, when the number of wirings is as large as 14 and especially when a plurality of wirings are installed, there are problems in wiring materials, wiring man-hours, reliability, maintenance, and the like.

An object of the present invention is to solve the above-mentioned conventional problems and to provide an incremental encoder capable of reducing the number of wirings.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an encoder according to the present invention comprises: 1. an incremental signal of A and B phases having a phase difference of 90 degrees from each other and a reference signal generated once per rotation; An original signal output unit for optically or magnetically detecting a Z-phase signal and a motor excitation position signal U-phase, V-phase, and W-phase; and 2, an incremental signal of the A-phase and a B-phase and a Z-phase signal of a reference signal. A buffer circuit for outputting to the outside; 3; motor excitation position signals U-phase, V-phase, and W-phase;
A latch circuit for holding the state of the two signals; and a parameter storage circuit for storing parameter values such as the externally applied resolution of A and B phases and the torque constant and inertia coefficient of the added motor. An output changeover switch for selecting whether to output the parallel information of the latch circuit output or the parallel information of the parameter storage circuit by time-division serial data provided from outside; and 6, time-division the selected parallel data. A parallel-to-serial conversion circuit for converting the serial data into a serial data; 7, a bidirectional buffer circuit for transmitting the serial signal to the outside or receiving time-division serial data given from the outside; A serial converter that converts time-division serial data supplied externally for storage into parallel. -
A parallel conversion circuit; and 9, a switching determination circuit for determining whether to switch an input / output direction of an output switch, an input switch, or a bidirectional buffer circuit based on output data of the serial-parallel conversion circuit. I have.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention relates to an A and B-phase incremental signal having a phase difference of 90 degrees, a Z-phase signal of a reference signal generated once per rotation, and a motor winding. An original signal output section for optically or magnetically detecting motor excitation position signals U, V, and W corresponding to the lines U, V, and W; and an incremental signal for the A and B phases and a reference signal. A buffer circuit for outputting a Z-phase signal to the outside, and the motor excitation position signal U
A latch circuit for holding three states of each of the three phases, V-phase and W-phase, and a parameter value for storing parameter values such as externally provided resolution of A and B phases and torque constants and inertia coefficients of added motors. A parameter storage circuit, an output changeover switch for selecting which of the parallel information output from the latch circuit and the parallel information output from the parameter storage circuit is output by time-division serial data externally provided, and the selected parallel data , A parallel-serial conversion circuit for converting the data into time-division serial data, a bidirectional buffer circuit for transmitting the serial signal to the outside or receiving time-division serial data given from the outside, and storing parameter values. To convert time-division serial data supplied from outside - a parallel conversion circuit, the serial - a encoders and a switching determination circuit for determining the switching input and output direction of the output selector switch and input switch and bidirectional buffer circuit by the output data of the parallel converter.

A and B having a phase difference of 90 degrees from each other
The phase-incremental signal, the Z-phase signal of the reference signal generated once per rotation, and the motor excitation position signals U-phase, V-phase, and W-phase corresponding to the motor winding U-phase, V-phase, and W-phase are optically or magnetically. A latch circuit for holding each of the six signals of the A and B incremental signals, the Z signal of the reference signal, and the motor excitation position signals U, V, and W phases. A, B given from outside
A parameter storage circuit for storing parameter values such as a phase resolution and a torque constant and an inertia coefficient of a motor to be added, and whether to output parallel information of the latch circuit output or parallel information of the parameter storage circuit are determined externally. An output change-over switch for selecting by the time-division serial data given from the controller, a parallel-serial conversion circuit for converting the selected parallel data to the time-division serial data, and transmitting the serial signal to the outside or receiving the signal from the outside. Bidirectional buffer circuit for receiving time-division serial data, serial-parallel conversion circuit for parallel-converting time-division serial data externally provided for storing parameter values, and the serial-parallel conversion circuit Output switch, depending on the output data of An encoder that and a switching determination circuit for determining the switching input and output force change-over switch and a bidirectional buffer circuit.

Further, A, having a phase difference of 90 degrees from each other,
The B-phase incremental signal, the Z-phase signal of the reference signal generated once per rotation, and the motor excitation position signals U-phase, V-phase, and W-phase corresponding to the motor winding U-phase, V-phase, and W-phase are optically or An original signal output unit for detecting by magnetism, a counter circuit for counting the A and B incremental signals, a Z-phase signal of the reference signal, and a motor excitation position signal U
A latch circuit for holding four signals for each of the phase, V-phase, and W-phase, and storing parameter values such as externally provided resolution of A and B phases, torque constant and inertia coefficient of an added motor. A parameter storage circuit for performing the operation, an output changeover switch for selecting which of the parallel information output from the latch circuit and the parallel information output from the parameter storage circuit is to be output based on time-division serial data supplied from the outside, A parallel-serial conversion circuit for converting parallel data into time-division serial data, a bidirectional buffer circuit for transmitting the serial signal to the outside or receiving time-division serial data given from the outside, and a parameter value Serial-to-parallel conversion of time-divided serial data given from outside to store And Parallel conversion circuit, the serial -
The encoder includes an output changeover switch, an input changeover switch, and a switching determination circuit that determines whether to switch input / output directions of a bidirectional buffer circuit based on output data of a parallel conversion circuit.

As described above, the parameters are stored in the parameter storage circuit in advance, and the information of the encoder and the motor to be mounted can be read out at the motor control device side on the receiving side when the power is turned on or when necessary. It is not necessary to set the parameters of the motor to be manually input by the motor control device. In addition, by using bidirectional serial communication, signal lines can be transmitted and switched by one system of serial communication, and parameters can be stored and read arbitrarily when necessary.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, 101 is an original signal output unit, 102 is a latch circuit, 103 is a parameter storage circuit, 104 is a modem unit, and a parallel-serial conversion circuit 105, a serial-parallel conversion circuit 106, It comprises a switching determination circuit 107, an input switch 108, and an output switch 109. 110 is a bidirectional buffer circuit, and 111 is a buffer circuit.

The configuration of the original signal output unit 101 is the same as that of the conventional incremental encoder, and the light emitting element 40 shown in FIG.
1. The optical configuration includes a light receiving element 402, a rotating slit plate 403, a fixed slit plate 404, and a waveform shaping circuit 405.

Next, the operation of the encoder can be roughly classified into a mode for outputting position information, a mode for storing parameters,
There is a mode for transmitting parameters. First, in the mode for outputting position information, the original signal output unit 101 outputs the A, B, and Z phases of the encoder and the U-phase and V-phase motor excitation position signals.
The phase and the W phase are optically detected to generate a logic signal that can be digitally processed. And, among these output signals, A,
The B and Z phase signals are transmitted to the outside via the buffer circuit 111. The U-phase, V-phase, and W-phase motor excitation position signals are held in a state by the latch circuit 102, and are converted into a time-division serial signal by the parallel-serial conversion circuit 105 via the output switch 109 of the modem unit 104. The data is transmitted to the outside via the bidirectional buffer circuit 110.

On the other hand, in a mode in which parameters are stored in the encoder, parameter data is externally input as a time-division serial signal, and the bidirectional buffer circuit 110, the serial-parallel conversion circuit 106 of the modem unit 104, and the input switch 108 are operated. Then, data such as the model of the motor, the number of poles, the induced voltage constant, the torque constant, the temperature coefficient, the inertia coefficient, and the like are stored in the parameter storage circuit 103 serving as the RAM of the nonvolatile memory.

Conversely, in the mode in which the parameters are output to the encoder, the data stored in the parameter storage circuit 103 is output to the output switch of the modem unit 104 in the same manner as the output of the motor excitation position signals U, V, and W phases. The signal is converted into a time-division serial signal by the parallel-serial conversion circuit 105 via the communication circuit 109, and transmitted to the outside via the bidirectional buffer circuit 110.

Further, these modes can be switched by externally inputting a command by a time-division serial signal.
A switching determination circuit 107 is provided via a bidirectional buffer circuit 110 and a serial-parallel conversion circuit 106 of the modem unit 104.
To determine the mode switching, and switch the transmission / reception signal direction of the input switch 108, the output switch 109, and the bidirectional buffer circuit 110.

Thus, the motor excitation position signals U phase, V
The number of phase and W-phase output lines can be reduced from six to two, and all 14 lines can be reduced to ten lines.

(Embodiment 2) In FIG. 2, 101 is an original signal output unit, 102 is a latch circuit, 103 is a parameter storage circuit, 104 is a modem unit, 105 is a parallel-serial conversion circuit, and 106 is a serial-parallel conversion circuit. , 1
07 is a changeover determination circuit, 108 is an input changeover switch, 10
9 is an output changeover switch, and 110 is a bidirectional buffer circuit.

In the second embodiment, since the latch circuit 102 handles the six output signals of the original signal output unit 101, a buffer circuit is not required, and the operation of the encoder is similar to that of the first embodiment. There are a mode for outputting, a mode for storing parameters, and a mode for transmitting parameters.

First, in the operation of the mode for outputting the position information of the encoder, the original signal output unit 101 detects six signals of A, B, Z phases and motor excitation position signals U, V, and W phases and performs digital processing. Generates a possible logic signal. The state of the six output signals is held by the latch circuit 102,
The signal is converted into a time-division serial signal by a parallel-serial conversion circuit 105 via an output switch 109 of the modem unit 104, and transmitted to the outside via a bidirectional buffer circuit 110.

In the mode in which parameters are stored in the encoder and the mode in which parameters are output, data can be transmitted / received to / from the outside via the modem unit 104 and the bidirectional buffer circuit 110 as in the first embodiment.

Thus, the A, B, and Z phase signals and U,
The output lines for the V and W phase signals can be reduced from 12 lines to two lines, and can be reduced to four lines including two lines for the power supply.

(Embodiment 3) In FIG. 3, 101 is an original signal output unit, 301 is a counter circuit, 102 is a latch circuit, 103 is a parameter storage circuit, 104 is a modem unit,
105 is a parallel-serial conversion circuit, 106 is a serial-parallel conversion circuit, 107 is a switching determination circuit, 108
Is an input switch, 109 is an output switch, 11
0 is a bidirectional buffer circuit.

In the third embodiment, the A and B phase signals are sent to the counter circuit 301 instead of the buffer circuit of the first embodiment, and the Z phase signal and the motor excitation position signals U, V and W phases are sent to the latch circuit 102. The state is held, and the parallel-serial conversion circuit 10 is output through the output switch 109 of the modem unit 104.
In step 5, the signal is converted into a time-division serial signal and transmitted to the outside via the bidirectional buffer circuit 110. The operation of the encoder also has a mode for outputting position information, a mode for storing parameters, and a mode for transmitting parameters,
In the mode in which the position information is output, the original signal output unit 101 detects the A, B, and Z phase signals and the motor excitation position signals U, V, and W phases in the same manner as in the first embodiment, and outputs a logical signal that can be digitally processed. Generate. The output signals A and B are counted by the counter circuit 301 and become parallel data.

The counter may have a preload function for adding or subtracting a value stored in advance in the parameter storage circuit.

Further, in the mode for storing parameters in the encoder and the mode for outputting parameters, data is transmitted and received between the modem unit 104 and the outside via the bidirectional buffer circuit 110 as in the first embodiment.

Similarly, A, B, Z phase signals and U, V,
The number of output lines of the W-phase signal can be reduced from twelve to two, and can be reduced from fourteen to four.

As is apparent from the first, second and third embodiments, the number of output lines can be reduced by serial communication with storage means in which the parameters of the encoder and the motor to be mounted are written.

[0033]

As is apparent from the above embodiment, the following effects can be expected by using the storage circuit in which the parameters are written in the encoder and the bidirectional serial communication. 1. Eliminates the need for parameter setting on the motor control device side.
Any combination is possible. 2. Product models can be reduced. 3. Since the number of wirings is reduced, manufacturing costs are reduced, wiring materials and wiring man-hours are reduced, reliability is improved, and maintenance is advantageous. 4. In particular, according to the second and third aspects, the number of wirings can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an encoder according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an encoder according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an encoder according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional encoder.

[Explanation of symbols]

 Reference Signs List 101 Original signal output unit 102 Latch circuit 103 Parameter storage circuit 105 Parallel-serial conversion circuit 106 Serial-parallel conversion circuit 107 Switching determination circuit 108 Input switching switch 109 Output switching switch 110 Bidirectional buffer circuit 111 Buffer circuit 301 Counter circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Furumai 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 2F077 AA46 JJ07 PP11 PP19

Claims (3)

[Claims] 1. A motor excitation corresponding to an A-phase incremental signal and a B-phase incremental signal having a phase difference of 90 degrees, a Z-phase signal of a reference signal generated once per rotation, and U-phase, V-phase, and W-phase motor windings. An original signal output unit for optically or magnetically detecting the position signals U, V, and W phases, and a buffer circuit for outputting the A and B incremental signals and the Z signal of the reference signal to the outside, respectively. And a latch circuit for holding the three states of the motor excitation position signals U, V, and W phases, and externally provided resolutions of the A and B phases, the torque constant and inertia coefficient of the added motor, and the like. A parameter storage circuit for storing parameter values of
An output changeover switch for selecting which of the parallel information output from the latch circuit and the parallel information output from the parameter storage circuit to output by time-division serial data externally provided, and a time-division serial A parallel-serial conversion circuit for converting data, a bidirectional buffer circuit for transmitting the serial signal to the outside or receiving time-division serial data given from the outside, and an external for storing the parameter value. A serial-parallel conversion circuit for converting given time-division serial data into parallel data, and a switch for judging whether to switch an input / output direction of an output changeover switch, an input changeover switch, or a bidirectional buffer circuit according to output data of the serial-parallel conversion circuit. An encoder having a judgment circuit . 2. A motor excitation corresponding to an A-phase incremental signal and a B-phase incremental signal having a phase difference of 90 degrees from each other, a Z-phase signal of a reference signal generated once per rotation, and motor winding U-phase, V-phase, and W-phase. An original signal output unit for optically or magnetically detecting the position signals U-phase, V-phase, and W-phase; the A- and B-phase incremental signals, the Z-phase signal of the reference signal, the motor excitation position signals U-phase, V-phase, A latch circuit for holding each of the six signals of the W phase, a parameter storage circuit for storing parameter values such as an externally applied resolution of the A and B phases, a torque constant of the motor to be added, and an inertia coefficient;
An output changeover switch for selecting whether to output the parallel information of the latch circuit output or the parallel information of the parameter storage circuit by time-division serial data externally provided, and time-division serial data of the selected parallel data; A parallel-serial conversion circuit for converting the serial signal and transmitting the serial signal to the outside,
A bidirectional buffer circuit for receiving time-division serial data given from outside, a serial-parallel conversion circuit for parallel-converting time-division serial data given from outside to store parameter values, An encoder comprising: an output changeover switch, an input changeover switch, and a switching determination circuit that determines whether to switch input / output directions of a bidirectional buffer circuit based on output data of a parallel conversion circuit. 3. A motor excitation corresponding to an incremental signal of A and B phases having a phase difference of 90 degrees from each other, a Z phase signal of a reference signal generated once per rotation, and U, V, and W phases of motor windings. An original signal output unit for detecting the position signals U, V, and W phases optically or magnetically, a counter circuit for counting the A and B incremental signals, a Z phase signal of the reference signal, and a motor excitation position. Signal U phase, V phase,
A latch circuit for holding four signals for each of the W phases, and a parameter storage for storing parameter values such as the externally applied resolution of the A and B phases and the torque constant and inertia coefficient of the added motor. A circuit, an output changeover switch for selecting whether to output the parallel information of the latch circuit output or the parallel information of the parameter storage circuit by time-division serial data externally provided, and time-division the selected parallel data. A parallel-serial conversion circuit for converting the serial signal to external data, a bidirectional buffer circuit for transmitting the serial signal to the outside or receiving time-division serial data given from the outside, and a memory for storing parameter values. Serial-parallel conversion for parallel conversion of time-division serial data given from outside Circuit and its serial - encoders and a switching determination circuit for determining the switching input and output direction of the output selector switch and input switch and bidirectional buffer circuit by the output data of the parallel converter.