JPH07312889A - Servo mechanism for motor with sensor - Google Patents

Abstract

PURPOSE:To provide a servo mechanism for a motor with a sensor in which the number of signal lines for connecting the body of the motor to a controller can be reduced. CONSTITUTION:A plurality of parallel censor signals to be output from a plurality of position detectors 29, 30, 31 are converted to one serial signal by a parallel-to-serial converting shift register 34 of a motor side. This serial signal is transmitted to a controller 12 via transmitting means 13. The serial signal is converted to a plurality of parallel sensor signals by a serial-to-parallel converting shift resister 35 of the controller side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo mechanism for a motor with a sensor for controlling a motor including a plurality of sensors such as a brushless motor and a switched reluctance motor.

[0002]

2. Description of the Related Art A brushless motor includes a position detecting element for detecting the position of the rotor, an encoder for detecting the rotation angle and the rotation direction of the rotor, and an overheat protection switch for the motor. Then, for example, in the case of a three-phase brushless motor, three position detection signals (U phase signal, V phase signal, W phase signal) are output from three position detection elements, and three rotation detection signals (A phase) from the encoder. Signal, B-phase signal, Z-phase signal) and one detection signal (OH signal) from the overheat protection switch. A control device for controlling such a brushless motor is configured to receive seven detection signals output from the above-mentioned sensors of the brushless motor. An example of such a configuration is shown in FIG. As shown in FIG. 11, between the main body 1 of the brushless motor and the control device 2, seven signal lines 3a to 3g for transmitting the above seven detection signals are connected and two power sources are connected. The lines 4a and 4b are connected. Further, when the main body 1 and the control device 2 are separated from each other, each signal line may be of a differential line drive system. In this case, as shown in FIG. Since two signal lines are required to transmit a signal, 14 signal lines and two power supply lines are connected.

On the other hand, an example of a configuration for controlling a four-phase switched reluctance motor is shown in FIGS. 13 and 14. In the case of this configuration, as shown in FIG. 13, six signal lines 7a to 7f for transmitting six detection signals are connected between the main body 5 of the switched reluctance motor and the controller 6. Two power lines 8a and 8b are connected. When each signal line is of the differential line drive system, 12 signal lines and 2 power supply lines are connected, as shown in FIG.

[0004]

When the motor is used in a machine tool such as a robot, a plurality of the motors are provided at the tip of the arm of the robot and the plurality of the motors are provided in the main body of the robot. The respective control devices for the motor are arranged. Since the number of connecting lines connecting between the plurality of motors and each control device is a multiple of the total number of the signal lines and the power supply lines described above, the number is considerably large, and the number of these connecting lines is large. The cable in which the wires are bundled has a very large thickness, which makes it difficult to secure a space for disposing the cable. Further, in the connector required for connecting the above-mentioned many connecting wires to the control device side or the motor side, the number of contacts is very large, and the reliability of contact is deteriorated.

Therefore, an object of the present invention is to provide a servo mechanism for a motor with a sensor, which can reduce the number of connecting lines, particularly signal lines, which connect the main body of the motor with a sensor and a control device. is there.

[0006]

A servo mechanism for a motor with a sensor according to the present invention comprises a motor with a sensor, a control device arranged at a position distant from the motor with the sensor, and a plurality of sensors of the motor with the sensor. In a servo mechanism for a motor with a sensor, which is configured to transmit the sensor signal to be output to the control device, and which is configured to control the motor with the sensor based on the plurality of sensor signals by the control device, The parallel-serial signal conversion means provided on the motor side for converting a plurality of parallel sensor signals output from the plurality of sensors into one serial signal is provided, and the parallel-serial signal provided on the control device side. The present invention is characterized in that a serial-parallel signal conversion means for converting a serial signal output from the conversion means into a plurality of parallel sensor signals is provided. It is intended to.

In this structure, the parallel-serial signal conversion means is constituted by a parallel-serial conversion shift register circuit, and the serial-parallel signal conversion means is constituted by a serial-parallel conversion shift register circuit, and A latch signal and a clock signal for controlling the operation of the parallel-serial conversion shift register circuit, and a serial signal output from the parallel-serial conversion shift register circuit are transmitted through the transmission means. Preferably. In this configuration, the phase of the clock signal that controls the shift operation of the parallel-serial conversion shift register circuit is shifted from the phase of the clock signal that controls the shift operation of the serial-parallel conversion shift register circuit. It is also possible. Further, it is even more preferable that the transmission means is constituted by a differential line drive system.

[0008]

According to the above means, the parallel-serial signal conversion means on the motor side converts a plurality of parallel sensor signals output from a plurality of sensors into one serial signal, and controls the serial signals through the transmission means. To the device,
The serial signal is converted into a plurality of parallel sensor signals by the serial-parallel signal conversion means on the control device side. As a result, the transmission means need only transmit one serial signal instead of a plurality of parallel sensor signals, and therefore the number of signal lines for signal transmission can be significantly reduced. It is necessary to transmit the control signal for controlling the operation of the parallel-series signal conversion means on the motor side from the control device to the motor through the transmission means. However, the above-mentioned control signals are about two, and therefore necessary. Since the number of such signal lines is about two, the effect of reducing the number of signal lines is not impaired.

In this case, specifically, the parallel-serial signal conversion means is constituted by a parallel-serial conversion shift register circuit, and the serial-parallel signal conversion means is constituted by a serial-parallel conversion shift register circuit, And parallel-
If the latch signal and clock signal for controlling the operation of the serial conversion shift register circuit and the serial signal output from the parallel-serial conversion shift register circuit are transmitted through the transmission means, It is possible to sufficiently reduce the number. Furthermore, in this configuration, the phase of the clock signal that controls the shift operation of the parallel-serial conversion shift register circuit and the phase of the clock signal that controls the shift operation of the serial-parallel conversion shift register circuit are shifted. If so, the accuracy of signal transmission control is improved. Further, if the transmission means is constituted by the differential type line drive system, noise can be reduced when the distance between the motor and the control device becomes long, and high speed transmission can be further achieved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a servo mechanism of a three-phase brushless motor will be described below with reference to FIGS. First, in FIG. 1 showing a schematic electrical configuration of a servo mechanism of a three-phase brushless motor, a transmission means 13 for transmitting a sensor signal is provided between a main body 11 of the three-phase brushless motor and a control device 12. . This transmission means 13 comprises three signal lines 14, 15, 1
It is composed of 6 and two power lines 17 and 18. In this case, three signal lines 14 are provided between each of the three signal terminals 19, 20, 21 provided on the motor body 11 side and the three signal terminals 22, 23, 24 provided on the control device 12. ,
Connected by 15 and 16, a + 5V power supply terminal 25 provided on the motor body 11 side and a + provided on the control device 12
Connected to the 5V power supply terminal 26 by the power supply line 17,
The power supply line 18 is provided between the GND terminal 27 provided on the motor body 11 side and the GND terminal 28 provided on the control device 12.
Connected by.

Next, the structure of the motor body 11 side will be described. In this case, the mechanical structure of the three-phase brushless motor (for example, the rotor, the stator, the stator winding, etc.) is omitted from the drawing. The motor body 1
On the first side, the position detecting means for detecting the rotational position of the rotor is composed of, for example, three position detecting elements 2 including Hall elements.
It is composed of 9, 30, and 31. These three position detecting elements 29, 30, 31 are configured to output a U-phase signal, a V-phase signal, and a W-phase signal, respectively, as position detection signals. The encoder 32 that detects the rotation angle, the rotation direction, etc. of the rotor is configured to output an A-phase signal, a B-phase signal, and a Z-phase signal as three rotation detection signals that specify the rotation angle, the rotation direction, and the like. Has been done.

Further, the thermal switch 33, which operates by detecting the temperature of the brushless motor, is arranged in the vicinity of the stator winding, and is turned off (or turned on) when the detected temperature exceeds a set temperature. As OH
It is configured to output a (bar) signal. The thermal switch 33 is an overheat protection switch for protecting the brushless motor from overheating. in this case,
The position detection elements 29 to 31, the encoder 32, and the thermal switch 33 form a plurality of sensors provided in the brushless motor.

The respective signals from the position detecting elements 29 to 31, the encoder 32 and the thermal switch 33 are arranged to be given to a parallel-serial signal converting means such as a parallel-serial conversion shift register circuit 34. There is. The parallel-serial conversion shift register circuit 34 is
This circuit has a latch function and converts a plurality of parallel sensor signals output from the above-mentioned sensors into one serial signal as described later in detail.
In this case, the U-phase signal from the position detection element 29 is given to the B input terminal of the parallel-serial conversion shift register circuit 34, and the V-phase signal from the position detection element 30 is supplied to the parallel-serial conversion shift register circuit 34. The W-phase signal supplied to the C input terminal is supplied to the D-input terminal of the parallel-serial conversion shift register circuit 34, and the A-phase signal is supplied from the encoder 32 to the parallel-serial conversion shift register circuit. The B-phase signal supplied from the encoder 32 to the E input terminal of the encoder 32 is connected to the parallel-to-serial conversion shift register circuit 3
4 to the F input terminal of the encoder 32, the Z-phase signal from the encoder 32 to the G input terminal of the parallel-serial conversion shift register circuit 34, the OH signal from the thermal switch 33 parallel-serial conversion shift register circuit. 34 is provided to the A input terminal.

Further, the H input terminal of the parallel-serial conversion shift register circuit 34 is GND (held at a low level), and the S / L of the parallel-serial conversion shift register circuit 34.
A LATCH (bar) signal is applied as a latch signal from the signal terminal 21 to the (bar) terminal, a PISOCLK signal is applied as a clock signal from the signal terminal 20 to the CLK terminal, and a + 5V DC voltage is applied to the SI terminal. Is configured. The latch signal (LATCH
The (bar) signal) and the clock signal (PISOCLK signal) are signals for controlling the operation (shift operation and latch operation) of the parallel-serial conversion shift register circuit 34. The QH terminal of the parallel-serial conversion shift register circuit 34 is connected to the signal terminal 19,
An SI signal is output as the serial signal from the QH terminal.

Next, the control device 12 side will be described.
In this case, a drive circuit for energizing and driving the brushless motor, a control circuit for controlling the drive circuit, and the like are not shown. On the control device 12 side, a serial-parallel signal converting means such as a serial-parallel conversion shift register circuit 35 receives the serial signal from the signal terminal 22 at its SIA terminal, and C
The LK terminal is configured to receive the SIPOCLK signal as a clock signal. The serial-parallel conversion shift register circuit 35 is a circuit that converts the serial signal into a plurality of parallel sensor signals. Series-
The QA terminal, QB terminal, QC terminal, QD terminal, QE terminal, QF terminal, and QG terminal of the parallel conversion shift register circuit 35 are the D1 terminal, D2 terminal, D3 terminal, D4 terminal, D5 terminal, and D6 of the latch circuit 36. It is connected to the terminal and D7 terminal. A LATCH signal is applied to the CLK terminal of the latch circuit 36 as a latch signal. This LATCH signal and the SIPOCL
The signal generating means 37 for generating the K signal and the PISOCLK signal is provided on the control device 12 side. The signal generating means 37 is configured by connecting a clock generating circuit 38, a ring counter 39, a capacitor 40 and a logic circuit group as shown in the figure. The parallel-serial conversion shift register circuit 34 is "74HC165", and the serial-parallel conversion shift register circuit 35 is "74HC16".
4 ", the latch circuit 36 is configured using a high speed logic IC such as" 74HC377 ".

Next, the operation of the above configuration will be described with reference to the time chart of FIG. First, CLK is used as a source clock signal from the clock generation circuit 38 of the signal generation circuit 37.
Two signals are output. Then, as a clock signal whose phase is delayed by a minute time Δt from this CLK2 signal, CL
The K1 signal is generated and this CLK1 signal is given to the ring counter 39. The minute time .DELTA.t is set to the minimum time during which the logic IC in use responds reliably, and is set by the capacitor 40.

When the ring counter 39 receives the CLK1 signal and counts for eight, it outputs a high level signal from the QD terminal. Then, the ring counter 39 outputs the QD output and the AN of the CLK2 (bar) signal.
It is configured to be cleared by the CLR signal that is the D output, and is configured to perform a ring count operation of 8 counts. The count number is set according to the number of signals to be transmitted, and specifically, is the number of signals to be transmitted plus one.

The AND output of the QD output and the CLK2 signal is the LATCH signal, and the LATCH (bar) signal obtained by inverting the LATCH signal is the control device 1.
The motor main body 11 from the signal terminal 24 of 2 through the signal line 16
The signal is supplied to the parallel-to-serial conversion shift register circuit 34 through the signal terminal 21 of FIG. Specifically, as shown in FIG. 2, LATCH
At the falling time t1 of the signal, seven sensor signals (OH) received by the parallel-serial conversion shift register circuit 34 are received.
(Bar) signal, U-phase signal, V-phase signal, W-phase signal, A-phase signal, B-phase signal, Z-phase signal) are simultaneously latched.

Subsequently, the CL from the signal generating means 37
The K1 signal is supplied as a PISOCLK signal from the signal terminal 23 of the control device 12 through the signal line 15 and the signal terminal 20 of the motor body 11 to the parallel-to-serial conversion shift register circuit 34 for parallel-to-serial conversion. The shift operation of the shift register circuit 34 is performed. As a result, a serial signal (SI signal) is output from the QH terminal of the parallel-serial conversion shift register circuit 34 by serially arranging the seven signals in the reverse order of the above. Specifically, at the time of latching t1, the seven signals are in a state as shown in FIG. 2, that is, the OH (bar) signal is at a low level, the U-phase signal is at a high level, the V-phase signal is at a high level, and the W-phase signal is at a W-phase. Signal is low level, A phase signal is high level, B phase signal is low level,
It is assumed that the Z-phase signal is at high level. In this state, P
At the rising edge of the first pulse of the ISOCLK signal, Q
The H terminal becomes the high level which is the signal level of the Z-phase signal, and at the rising edge of the second pulse of the PISOCLK signal, the QH terminal becomes the low level which is the signal level of the B-phase signal, and the rising edge of the third pulse. Then, the QH terminal becomes high level which is the signal level of the A phase signal, and
At the rising edge of the sixth pulse, the QH terminal changes to the low level, which is the signal level of the W-phase signal, and at the rising edge of the fifth pulse, the QH terminal changes to the high level, which is the signal level of the V-phase signal. At the rising edge of the eye pulse,
The QH terminal becomes the high level which is the signal level of the U-phase signal, and at the rising edge of the seventh pulse, the QH terminal becomes O level.
It becomes a low level which is the signal level of the H (bar) signal.

The serial signal (SI signal) which changes high and low in this way is the signal terminal 1 of the motor body 11.
9 through the signal line 14 and the signal terminal 2 on the side of the control device 12
It is given to the serial-to-parallel conversion shift register circuit 35 through the line 2. In the serial-parallel conversion shift register circuit 35, a shift operation is performed by a clock signal (SIPOCLK signal) that is synchronized with the clock signal (PISOCLK signal) and is out of phase by half a cycle.
The signal state of the QA terminal or the QG terminal of the serial-parallel conversion shift register circuit 35 changes as shown in FIG.
The serial signal is converted into seven parallel sensor signals. Specifically, the QA terminal goes high at the rising edge of the first pulse of the SIPOCLK signal, and the QA terminal goes low at the rising edge of the second pulse.
The QB terminal becomes high level, and then changes as shown in FIG. 2. At the rising edge of the seventh pulse, the QA terminal becomes low level, the QB terminal becomes high level, and Q
The C terminal becomes high level, the QD terminal becomes low level, the QE terminal becomes high level, the QF terminal becomes low level, and the QG terminal becomes high level. In this case, Q
The signal state of the A terminal corresponds to the OH (bar) signal, the signal state of the QB terminal corresponds to the U phase signal, the signal state of the QC terminal corresponds to the V phase signal, and the signal state of the QC terminal corresponds to the W phase signal. , The signal state of the QE terminal corresponds to the A-phase signal,
The signal state of the terminal corresponds to the B-phase signal, and the signal state of the QG terminal corresponds to the Z-phase signal.

The signals from the QA terminal to the QG terminal of the serial-parallel conversion shift register circuit 35 are applied to the D1 terminal to the D7 terminal of the latch circuit 36. Then, the latch circuit 36 causes the latch signal (LATCH
At the rising time t2 of the (signal), the input signal received at the D1 to D7 terminals is latched and output to the output terminals Q1 to Q7. Thereby, from the output terminal Q1 to the output terminal Q7, the seven sensor signals (OH (bar) signal, U phase signal, V phase signal, W phase signal, A phase signal, B phase signal, Z phase signal) are supported. 7 signals (oh (bar) signal, u phase signal, v phase signal, w phase signal, a phase signal, b phase signal, z phase signal) are output.

In the parallel-serial conversion shift register circuit 34, the next latch is performed at the time t1 ', and the same signal processing is performed thereafter. Therefore, in the above signal transmission, the CLK1 signal is 8
Each time a pulse is input (every time the pulse of the latch signal rises)
Then, seven sensor signals are transmitted.

According to the present embodiment having such a configuration, the parallel-to-serial conversion shift register circuit 3 on the motor body 11 side.
7 parallel sensor signals (OH (bar) signal, U phase signal, V phase signal, W phase signal, A phase signal, B phase signal, Z phase signal) output from a plurality of sensors The serial signal (SI signal) is converted into a serial signal (SI signal), and the serial signal (SI signal) is transmitted to the transmission means 13 (signal lines 14, 15, 1).
6) to the control device 12, and a serial-parallel conversion shift register circuit 35 on the control device 12 side converts the serial signal into seven parallel sensor signals (oh.
(Bar) signal, u phase signal, v phase signal, w phase signal, a phase signal, b phase signal, z phase signal). As a result, the transmission means 13 only has to transmit one serial signal instead of seven parallel sensor signals, so that the number of signal lines for signal transmission can be significantly reduced. Specifically, seven can be reduced to three. In the case of this configuration, as the control signal for controlling the operation of the parallel-to-serial conversion shift register circuit 34 on the motor main body 11 side, the latch signal and the clock signal are transmitted from the control device 12 to the motor main body 11 through the transmission means 13. Therefore, two signal lines 15 and 16 are required for the above two control signals. However, such an increase in the number of signal lines does not impair the effect of reducing the number of signal lines of the present invention.

In the above embodiment, the phase of the clock signal (PISOCLK signal) for controlling the shift operation of the parallel-serial conversion shift register circuit 34 and the shift operation of the serial-parallel conversion shift register circuit 35 are controlled. Since the phase of the clock signal (SIPOCLK signal) is shifted by a half cycle, the accuracy of signal transmission control can be improved.

FIGS. 3 to 9 show a second embodiment of the present invention, and the difference from the first embodiment will be described. The same parts as those in the first embodiment are designated by the same reference numerals. In the second embodiment, the transmission means 13 is constructed by the differential line drive system. In particular,
As shown in FIG. 3, instead of the signal lines 14, 15 and 16,
Each two signal lines 41a, 41b, 42a, 42b, 43
a and 43b are provided, a line driver 44 is provided on the signal sending side, and a line receiver 45 is provided on the signal receiving side. The differential line drive system is a transmission system that can cancel common noise when the transmission distance becomes long.

Here, the latch signal (LATCH (bar)
In the case of transmitting a signal), the differential type line drive method will be compared with the ordinary transmission method using one signal line. FIG. 4 shows a partial electric circuit of the ordinary transmission system, and FIG. 5 shows a partial electric circuit of the line drive system.
And, in the ordinary transmission method, the transmission code length is 2 m.
6 (a), (b), (c), and (d) show the respective signal waveforms at four points N, M, P, and Q in FIG.
Shown in. 7A, 7B, and 7C show signal waveforms at four points N, M, P, and Q in FIG. 4 when the transmission code length is 8 m in the ordinary transmission method. ),
It shows in (d). Further, in the line drive system, the eight points N, M, P, Q, N ′ (bar), N ′ and M of FIG. 5 when the transmission code length is 8 m.
′ (Bar) and signal waveforms at point M ′ are shown in FIG.
(B), (c), (d), (e), (f), (g),
It shows in (h).

The signal waveform at point N in FIG. 6 (a) and FIG.
Comparing with the signal waveform at point N in (a), the following can be seen. That is, in the ordinary transmission method, when the transmission code length is increased from 2 m to 8 m, in other words, the longer the transmission code length is, the more the transmission signal rises due to the mutual capacitance and the mutual inductance coupling between the adjacent transmission lines. At the time of rising and falling, a crosstalk phenomenon occurs and the signal waveform is distorted. Further, the influence on another (adjacent) signal line is also caused by the signal waveforms at points P and Q (see FIG. 6C).
Looking at (d) and FIGS. 7 (c) and (d), a resonance phenomenon having a large amplitude is recognized. This resonance frequency f0 is approximated by the following equation.

[0028]

[Equation 1] However, C0 is mutual capacitance between lines, and L0 is mutual inductance.

According to the above equation, it can be understood that the longer the transmission code length, the lower the resonance frequency, which makes it difficult to distinguish from the signal to be transmitted, and thus the high-speed transmission becomes difficult.

On the other hand, when the line drive system is used, as shown in FIG. 8, the signal waveform at the point N on the transmission side,
According to the signal waveform at the point N ′ (bar) and the signal waveform at the point N ′, it can be seen that the crosstalk phenomenon does not occur at the rising and falling edges of the signal. Further, according to the signal waveforms at points P and Q shown in FIGS. 8C and 8D, it can be seen that the influence on another signal line is small.

Then, the graph of FIG. 9 shows the result of an experiment to find the relationship between the transmittable clock frequency and the transmission code length in each of the ordinary transmission system and the line drive system. According to the graph of FIG. 9,
When the transmission code length is 6 m or more, the line drive method enables higher speed transmission, in other words, it is possible to further prevent adverse effects (noise generation) on other signal lines when performing high frequency transmission. I understand. In this case, noise resistance against external noise is not added.

FIG. 10 shows a third embodiment of the present invention, and the difference from the first embodiment will be described. still,
The same parts as those in the first embodiment are designated by the same reference numerals.
The third embodiment has a configuration applied to a 4-phase switched reluctance motor instead of the 3-phase brushless motor. In this configuration, the a ′ phase signal and the b ′ phase signal as the two position detection signals output from the two position detection elements 29 and 30, and the A phase as the three rotation detection signals output from the encoder 32. The signal, the B-phase signal, the Z-phase signal, and the OH (bar) signal as the switch signal output from the thermal switch 33 are transmitted to the control device 12 side. That is, six sensor signals are transmitted, and the six sensor signals are transmitted every time 7 pulses of the CLK1 signal are input (every pulse of the latch signal rises). Therefore,
Also in the second embodiment described above, it is possible to obtain substantially the same operational effects as in the first embodiment. The configuration other than the above is the same as the configuration of the first embodiment.

[0033]

As is apparent from the above description, the present invention converts a plurality of parallel sensor signals output from a plurality of sensors by the motor side parallel-serial signal conversion means into one serial signal, The serial signal is transmitted to the control device through the transmission means, and the serial-parallel signal conversion means on the control device side converts the serial signal into a plurality of parallel sensor signals. Since it is only necessary to transmit one serial signal in place of the parallel sensor signal of 1, there is an excellent effect that the number of signal lines for signal transmission can be significantly reduced.

Further, in the case of this configuration, specifically, the parallel-serial signal converting means is constituted by a parallel-serial converting shift register circuit, and the serial-parallel signal converting means is constituted by a serial-parallel converting shift register circuit. And a latch signal and a clock signal for controlling the operation of the parallel-to-serial conversion shift register circuit, and a serial signal output from the parallel-to-serial conversion shift register circuit, are transmitted through a transmission means. With this configuration, it is possible to sufficiently reduce the number of signal lines. Further, in the above configuration, the phase of the clock signal that controls the shift operation of the parallel-serial conversion shift register circuit and the phase of the clock signal that controls the shift operation of the serial-parallel conversion shift register circuit are shifted. If so, the accuracy of signal transmission control is improved. Further, if the transmission means is constituted by the differential type line drive system, noise can be reduced when the distance between the motor and the control device becomes long, and high speed transmission can be further achieved.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a first embodiment of the present invention.

[Figure 2] Time chart

FIG. 3 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 4 is a partial electric circuit diagram showing an ordinary transmission method.

FIG. 5 is a partial electric circuit diagram showing a line drive system.

FIG. 6 is a diagram showing a signal waveform of each part when the transmission code length is 2 m in the case of an ordinary transmission method.

FIG. 7 is a diagram showing a signal waveform of each part when the transmission code length is 8 m in the case of an ordinary transmission method.

FIG. 8 is a diagram showing a signal waveform of each part when the transmission code length is 8 m in the case of the line drive method.

FIG. 9 is a graph showing a result obtained by an experiment on a relationship between a transmittable clock frequency and a transmission code length in a normal transmission method and a line drive method.

FIG. 10 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 11 is an electric circuit diagram schematically showing a conventional configuration.

FIG. 12 is an electric circuit diagram schematically showing a different conventional configuration.

FIG. 13 is an electric circuit diagram schematically showing a different conventional configuration.

FIG. 14 is an electric circuit diagram schematically showing a different conventional configuration.

[Explanation of symbols]

11 is a main body, 12 is a control device, 13 is a transmission means, 14,
15, 16 are signal lines, 17, 18 are power lines, 29, 3
0 and 31 are position detection elements (sensors), 32 is an encoder (sensor), 33 is a thermal switch (sensor), 34
Is a parallel-serial conversion shift register circuit (parallel-serial signal conversion means), 35 is a serial-parallel conversion shift register circuit (serial-parallel signal conversion means), 36 is a latch circuit,
37 is a signal generating means, 41, 42 and 43 are signal lines, 44
Is a line driver, and 45 is a line receiver.

Claims (4)

[Claims] 1. A sensor-equipped motor, a control device arranged at a position distant from the sensor-equipped motor, and transmission means for transmitting sensor signals output from a plurality of sensors of the sensor-equipped motor to the control device. A servo mechanism for a motor with a sensor, which is configured to control the motor with a sensor based on the plurality of sensor signals by the control device, wherein a plurality of sensors provided on the motor side and output from the plurality of sensors are provided. Parallel-serial signal conversion means for converting the parallel sensor signal into a serial signal, and a serial signal output from the parallel-serial signal conversion means, which is provided on the control device side, and converted into a plurality of parallel sensor signals. A servo mechanism for a motor with a sensor, comprising: a serial-parallel signal converting means for converting into a servo signal. 2. The parallel-serial signal conversion means is configured by a parallel-serial conversion shift register circuit, and the serial-parallel signal conversion means is configured by a serial-parallel conversion shift register circuit. 2. A latch signal and a clock signal for controlling the operation of the conversion shift register circuit, and a serial signal output from the parallel-serial conversion shift register circuit are transmitted through the transmission means. Servo mechanism of the motor with the sensor described. 3. The servo mechanism for a motor with a sensor according to claim 1, wherein the transmission means is constituted by a differential line drive system. 4. The phase of a clock signal that controls the shift operation of the parallel-serial conversion shift register circuit and the phase of the clock signal that controls the shift operation of the serial-parallel conversion shift register circuit are deviated. The servo mechanism of the motor with a sensor according to claim 2, wherein