JP2009130990A - Drive unit for plural motors and control method for the unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit for a plurality of motors, which can drive control the motors so as to synchronize them by a sound control means even when a certain control means becomes abnormal, in a drive unit for driving control the plurality of motors while electrically synchronizing the motors with each control means. <P>SOLUTION: The drive unit comprises a plurality of AC motors 1-A, 1-B, encoders 2-A, 2-B for detecting the rotational speed/rotational position of each AC motor, and a plurality of controllers A, B for feeding back respective encoder signals according to a common speed signal from a speed command section 5 to drive each motor. In this constitution, when a certain controller of the plurality of controllers A, B becomes abnormal, the drive circuit is switched to perform synchronous driving of the plurality of AC motors 1-A, 1-B with a sound controller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a driving device that controls driving of a plurality of electric motors and a method for controlling the driving device. More specifically, the present invention relates to a control technique in a case where an abnormality occurs due to a failure or the like of each control device provided corresponding to each electric motor.

For example, in a device that drives a load with a plurality of electric motors, for example, Patent Literature 1 and Patent Literature 2 describe a control technique when abnormality or the like occurs in a control device or a power conversion device provided corresponding to each electric motor. There is something that is.
In the system described in Patent Document 1, two motors (six-phase induction motors) are provided, and in each of the systems provided with a PWM control circuit and a power converter corresponding to each motor, one of the PWM control circuits is faulty. In this case, the two power converters and the motor are driven while being synchronized via the sound side PWM control circuit to continue the operation.

  In Patent Document 2, when one inverter becomes abnormal due to a failure or the like, the inverter is disconnected and a plurality of electric motors are driven by a healthy inverter to continue operation.

JP 7-315712 A JP 7-194187 A

  However, the one described in Patent Document 1 is effective when the drive shafts of a plurality of electric motors are mechanically rotationally connected, but the plurality of motors are not mechanically rotationally connected. There is a situation that it is difficult to directly apply it to an apparatus that is connected only electrically and operates in synchronization to drive a load.

  Further, in the case of the one described in Patent Document 2, there is no guarantee that a plurality of motors that are only electrically connected can be continuously operated in synchronization with each other.

  The present invention has been made in view of the above-described situation, and in a drive device that drives and controls a plurality of electric motors while being electrically synchronized by the respective control means, even if an abnormality occurs in a certain control means, sound control is achieved. It is an object of the present invention to provide a drive device for a plurality of motors that can be driven and controlled so as to synchronize the plurality of motors by means, and a method for controlling the devices.

For this reason, the present invention
A plurality of electric motors that are not mechanically coupled to each other;
Information acquisition means for acquiring information related to the operating state of the corresponding motor (for example, rotation speed, rotation position, etc.);
The plurality of electric motors are provided corresponding to each of the plurality of electric motors, and the corresponding electric motors are driven and controlled based on a drive command, and the information acquired by the information acquisition unit is used as feedback information to operate the plurality of electric motors. A plurality of control means having a feedback function for correcting the drive command so as to synchronize
A plurality of electric motor drive devices comprising:
When a control means among the plurality of control means becomes abnormal, the drive control of the corresponding motor by the abnormal control means is stopped, and the abnormality is made through the sound control means. A plurality of electric motors including an electric motor corresponding to the control means are operated in synchronization.

  According to the present invention, when a certain control means among the plurality of control means becomes abnormal, by switching the drive circuit, the drive control of the corresponding electric motor by the abnormal control means is stopped, and An electric motor corresponding to the control means that has become abnormal may be connected in parallel with an electric motor that is driven and controlled via the sound control means.

  According to the present invention, when a certain control means among the plurality of control means becomes abnormal, by switching the drive circuit, the drive control of the corresponding electric motor by the abnormal control means is stopped, and An electric motor corresponding to the control means that has become abnormal can be connected in series with an electric motor that is driven and controlled via the sound control means.

  The present invention uses, as feedback information, information related to the driving state of the motor that has a maximum deviation between the drive command and information related to the driving state of each motor acquired by the information acquisition unit, The sound control means may drive-control a plurality of electric motors including an electric motor corresponding to the abnormal control means.

  The present invention uses, as feedback information, an average value of information related to the operation state of each motor acquired by the information acquisition unit, and the healthy control unit corresponds to the abnormal control unit. And a plurality of electric motors including the motor.

  The present invention feeds back the information related to the driving state of the motor with the maximum deviation based on the deviation between the drive command and the information related to the driving state of each motor acquired by the information acquisition means. Select whether to use as information, or to use as an feedback value the average value of information related to the operating state of each motor acquired by the information acquisition means, and based on the selected feedback information, the sound The control means can drive-control a plurality of electric motors including the electric motor corresponding to the abnormal control means.

  In the present invention, the sound control means imposes a limitation on the drive control so as to reduce a load when driving and controlling a plurality of electric motors including the electric motor corresponding to the abnormal control means. can do.

In the present invention, the plurality of electric motors can be used as driving sources for wheels.
In the present invention, the plurality of electric motors may be used as a drive source of the transport device.

Further, a method for controlling a plurality of electric motor drive devices according to the present invention includes:
A plurality of electric motors that are not mechanically coupled to each other;
Information acquisition means for acquiring information related to the operating state of the corresponding motor;
The plurality of electric motors are provided corresponding to each of the plurality of electric motors, and the corresponding electric motors are driven and controlled based on a drive command, and the information acquired by the information acquisition unit is used as feedback information to operate the plurality of electric motors. A plurality of control means having a feedback function for correcting the drive command so as to synchronize,
A method of controlling a drive device for a plurality of electric motors comprising:
When a control means among the plurality of control means becomes abnormal, the drive control of the corresponding motor by the abnormal control means is stopped, and the abnormality has occurred via the sound control means. A plurality of electric motors including an electric motor corresponding to the control means are operated in synchronization.

  According to the present invention, in a drive device that drives and controls a plurality of electric motors while being electrically synchronized by the respective control means with a simple and inexpensive configuration, even if an abnormality occurs in a certain control means, sound control can be performed. It is possible to provide a drive device for a plurality of motors that can be driven and controlled to synchronize the plurality of motors by means, and a method for controlling the devices.

  Hereinafter, an embodiment showing an example of a drive device for a plurality of electric motors according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

  FIG. 1 shows a schematic overall configuration of a drive device for a plurality of electric motors (for example, AC motors) according to a first embodiment of the present invention. As shown in FIG. 1, the present apparatus includes an A-system apparatus with a code -A added to the end of the code and a B-system apparatus with a code -B added to the end of the code. .

  AC motors 1-A and 1-B are operated in synchronization by control device A and control device B, respectively. The AC motors 1-A and 1-B are provided with encoders 2-A and 2-B for detecting the rotational speed and rotational position of each motor, respectively.

Control devices A and B receive a common speed command from speed command unit 5. The speed command from the speed command unit 5 and the speed detection signals from the encoders 2-A and 2-B are input to the speed control units 4-A and 4-B, respectively.
Here, the control devices A and B correspond to control means according to the present invention, and the encoders 2-A and 2-B correspond to information acquisition means according to the present invention.

  The speed controllers 4-A and 4-B work according to the deviation between the speed command and the respective speed detection signals, and operate the converters 3-A and 3-B of the respective systems. As converters 3-A and 3-B, for example, a three-phase PWM (Pulse Width Modulation) inverter is used.

  The three-phase AC output from the converter 3-A is input to the AC motor 1-A via the switching device 11-A. Similarly, the three-phase AC output from the converter 3-B is input to the AC motor 1-B via the switching device 11-B. The terminals of AC motor 1-A and 1-B are configured to be connectable to each other via switching device 21.

  The state monitoring control unit 6 receives signals from the speed command unit 5 and encoders 2-A and 2-B, and monitors the deviation between the command signal and the detection signal. Further, although not shown, signals for monitoring the operating states and abnormal states of the control devices A and B are also input.

Next, the operation of the drive device shown in FIG. 1 will be described.
In the normal operation state, that is, when there is no abnormality in the control devices A and B, the present device is operated according to the connection state shown in FIG.
That is, the switches of the switching devices 11-A and 11-B are closed, the switch of the switching device 21 is open, and the AC motors 1-A and 1-B are output from the respective converters 3-A and 3-B. Driven according to Thus, the control device A is operated according to the speed command from the speed command unit 5, and the control device B is also operated according to the same speed command as the control device A. Since the control device A and the control device B are operated at the same common speed command, they are electrically operated at the same speed, that is, operated in synchronization. In this example, it is assumed that the control devices A and B are operated by inputting a common speed command. However, even if the control devices A and B have separate speed command units, the speed commands are substantially always the same. It is equivalent to having a common speed command section if it is configured so that.

Here, the operation when abnormality occurs in either the control device A or B due to a failure or the like will be described with reference to FIG.
In FIG. 2, the same elements as those in FIG. FIG. 2 shows an example in which an abnormality occurs in the control device B and is disconnected, and the operation of the two motors 1-A and 1-B is continued by the healthy (normal) control device A.

  Since the operation is performed by the control device A, the switch of the switching device 11-A is closed and is the same as in the case of FIG. 1, but the switch of the switching device 11-B is switched to the open state and the switch of the switching device 21 is switched to the closed state. . In this way, AC motors 1-A and 1-B can be driven in parallel by converter 3-A.

  In the state shown in FIG. 2, the state monitoring control unit 6 causes the deviation between the speed command signal from the speed command unit 5 and the speed detection signal from the encoder 2-A, the speed command signal from the speed command unit 5, and the encoder. The deviation of the speed detection signal from 2-B is compared, and the signal from the encoder with the larger deviation is input to the speed control unit 4-A as a speed detection signal.

FIG. 3 shows a configuration example of the state monitoring control unit 6 described above.
The speed deviation unit 301-A calculates the deviation between the speed command signal from the speed command unit 5 and the speed detection signal from the encoder 2-A. The speed deviation unit 301-B calculates the deviation between the speed command signal from the speed command unit 5 and the speed detection signal from the encoder 2-B.

  The deviation determination unit 302 compares these deviations, operates the switching unit 303, and switches the switch of the switching unit 303 so as to select the larger deviation side as the speed detection signal. In FIG. 3, it is switched to the encoder 2-A side (side with a larger deviation) as an example.

The abnormality detection unit 305 determines whether the control device A or B is abnormal, and switches the switch of the switching unit 304 so as to send a speed detection signal to the control device that is not abnormal. In the example of FIG. 3, since the control device B is abnormal, it is switched to send a signal to the speed control unit 4-A.
As will be understood from the above description, when there is no abnormality in the control device A or B, the speed detection signals from the encoders 2-A and 2-B are sent to the respective speed control units 4-A and 4-B. It is sent as it is by another route.

  Here, the abnormality detection is performed by, for example, monitoring various signals input to the control devices A and B, control power supply voltage, output signals output from the control devices A and B, etc. This can be done by comparison. Further, each switch can be switched according to an abnormality notification based on an abnormality detection result of the abnormality detection unit 305, for example, by a manual operation by an operator.

Comparison of the deviation between the speed command signal and the speed detection signal in the deviation determination unit 302 described above can be performed as follows.
For example, the comparison may be performed in an instantaneous state or may be performed at a certain time interval. That is, the deviation can be compared at a predetermined time interval.
Moreover, not only in a steady state, but also, for example, a configuration in which a deviation is compared when a speed command is changed or during acceleration / deceleration can be employed.

  Further, monitoring and comparison may be performed in the normal operation state of FIG. 1, and an encoder to be used in the event of an abnormality may be determined in advance from the result (for example, the magnitude of deviation) (for example, abnormal After the occurrence, it can be used as a feed-forward control amount until the actual deviation is obtained). Such monitoring and comparison can be determined in accordance with the operation pattern, the operation state, or the rotational position of the motor.

  When the speed control of the AC motor 1-A is performed, when this example is applied to a synchronous motor that needs to detect its rotational position, the rotational position detected by the encoder also corresponds to the encoder selected by the deviation determination unit. Can be changed.

  As described above, in the present embodiment, when an abnormality occurs in one control device, a normal control device is connected so that a plurality of motors can be operated, and a detection signal for further control is selected. To do. In this way, for example, the converter 3-A is operated in accordance with the state of the motor with the larger load, so that the two motors can be reliably operated synchronously.

FIG. 4 shows another configuration example of the state monitoring control unit 6.
In FIG. 4, the average value of the rotational speeds of the two motors is taken as the speed detection signal. The signals of the encoder 2-A and the encoder 2-B are input to the average calculation unit 401, and the average value of both is calculated. The output of the average calculation unit 401 is selected as a speed detection signal and sent to the speed control unit 4-A or 4-B. When the speed control of AC motor 1-A is performed, when this example is applied to a synchronous motor that needs to detect its rotational position, the rotational position detected by the encoder is selected by the deviation determination unit as described above. The average position obtained through the encoder is used as the rotational position detection signal.
Even if it does in this way, when abnormality arises in one control apparatus, it can connect so that a several control motor can be drive | operated with a normal control apparatus, and the detection signal for further control can be selected. In this way, since the converter is operated in the average state of the two motors, the two motors can be reliably operated synchronously.

By the way, the deviation determination unit 302 described above acquires the deviation between the speed command signal and speed detection signal of one motor and the deviation between the speed command signal and speed detection signal of the other motor, and one of the deviations is predetermined. If it is larger than this, it is judged that the load on the corresponding motor is larger than a predetermined value, and if there is no significant difference between the two deviations, the state monitoring control is performed so that the load on both motors can be judged to be the same level. When the load of one motor is larger than a predetermined value according to the determination result, the synchronous control is performed using information obtained from the encoder of the motor with the larger load as shown in FIG. (Feedback control) While the load on both motors is approximately the same, the deviation is extended so that the synchronous control (feedback control) is performed using the average value shown in FIG. Depending on the load, the method of processing information obtained from the encoder may be automatically selectable configure.
With this configuration, when an abnormality occurs in one of the control devices, optimal drive control can be performed according to the loads of both motors.

  Next, in the abnormal state operation, a plurality of motors are driven from the same converter, and therefore the capacity of the converter may be insufficient if the same pattern operation is performed as normal. In order to prevent this, as shown in FIG. 2, it is conceivable to configure the state monitoring control unit 6 to output a suppression signal to the speed command unit 5 at the time of abnormality.

In such a case, upon receiving this suppression signal, the speed command unit 5 changes the speed command to a command value that suppresses the load, or / and issues a command that extends the acceleration / deceleration time, for example. In order to suppress the load, the command can be changed over the entire operation pattern, or the command can be changed only at a required portion to perform the operation.
In this way, by performing an operation that limits the load (torque) of the motor, the load on the converter can be reduced, and the converter can be protected from damage caused by insufficient capacity.

  In the above description, the state monitoring control unit 6 monitors the abnormality of the control devices A and B, and when abnormality occurs in either of the control devices, the control system is switched and driven as described above. The abnormality monitoring may be performed by another device. Further, the occurrence of an abnormality and the switching of the control system can be displayed by a host control device, a display device or the like to notify the device manager.

  Here, although the apparatus which consists of two multiple motors was demonstrated, it is materialized even when the number of motors is three or more. In addition, since the plurality of motors are driven from the same converter when the control apparatus is abnormal, an AC motor that basically performs synchronous operation can be used, and an induction motor, a synchronous motor, a stepping motor, and a reluctance motor can be applied as the AC motor. In addition to the AC motor, if the motor can be driven and controlled by synchronizing multiple motors by feedback control based on information from the encoder, for example, a PWM signal from the speed control unit instead of a converter or the like. The present invention can also be applied to a DC motor such as a DC servo motor provided with a drive circuit to which etc. are input.

  1 and 2 show an example in which the control devices A and B perform speed control, the speed command unit 5 is a position command unit, and the speed control units 5-A and 5-B are respectively position controlled. The present invention can also be applied to a system in which the position of the entire system is controlled using the rotational position signals of the encoders 2-A and 2-B. In this case, the deviation determination of the calculation in the state monitoring controller 6 is a determination of the position deviation, or the average calculation is an calculation of the average value of the positions. It should be noted that when the position control system is configured, it is preferable that the rotational mounting position of the AC motor be electrically matched.

  As described above, the intention of the present invention can be applied to any apparatus in which a plurality of motors are operated in synchronization with each other. However, in the example of the apparatus in FIG. More effective can be obtained when the system configuration specifications of the system are the same and the load characteristics driven by the motors 1-A and 1-B are substantially the same.

Next, a second embodiment of the present invention will be described.
FIG. 5 shows a connection example according to the second embodiment of the present invention. In FIG. 5, the same elements as those in FIG.

  In FIG. 1, the main circuit connection after abnormality determination is connected to the converter by connecting the motor in parallel as shown in FIG. 2, but in FIG. 5, the motor is connected in series and connected to the converter as shown in FIG. . Since the two motors 501-A and 501-B are connected in series when the control device A or B is abnormal, the three-phase AC output from the converter 3-A passes through the switching device 511-A. The AC motor 501-A is connected to one terminal. Similarly, the three-phase AC output from converter 3-B is connected to one terminal of AC motor 501-B via switching device 511-B. Further, the other terminals of AC motors 501 -A and 501 -B are connected to switching device 512. In normal operation, that is, in a normal state, the switching devices are connected as shown in FIG. 5, and the operation is exactly the same as in FIG. 1, and the two motors are operated in synchronization.

Here, the main circuit connection when an abnormality occurs in either the control device A or B will be described with reference to FIG.
FIG. 6 shows an example in which an abnormality occurs in the control device B and is disconnected, and the operation of the two motors 501-A and 501-B is continued in the control device A, and the main circuit connection in FIG. This is shown as a connection example.

The connection state of the switching device 511-A is the same as that in FIG. 5, but the connection state between the switching device 511-B and the switching device 512 is switched as shown in FIG. If it does in this way, AC motor 501-A and 501-B can be driven in series by converter 3-A. The operation of the control device and particularly the operation of the state monitoring control unit 6 are the same as those in FIG.
In this way, the intended purpose of the present invention can be realized, and the two motors can be operated in synchronism even when an abnormality occurs. In addition, according to the connection method at the time of abnormality shown in FIG. 6, high speed operation is restricted, but torque at low speed is ensured.

  In each of the above-described embodiments, the case where a three-phase motor is used has been representatively described. However, the present invention can be applied to a single-phase or multi-phase motor, and can also be applied to a multi-winding motor.

  As described above, the present invention can be applied as long as it is a device in which a plurality of motors are operated in synchronization with each other. As a more specific example, the following system is configured by two motors. FIGS. 7 and 8 illustrate examples in which the specifications of the system configurations of the B and B systems are the same, and the load characteristics driven by the two motors are substantially the same characteristics.

  FIG. 7 shows an example applied to a carriage. Such an example can be applied to a vehicle having wheels such as an electric vehicle, a crane, and a traveling carriage of a railway vehicle. As shown in FIG. 7, as in FIG. 1, a system A apparatus in which -A is added to the end of the code with a reference numeral number and a system B apparatus in which the reference -B is added to the end of the code are provided. It is done. Wheels 72 -A and 72 -B are connected to AC motors 71 -A and 71 -B, respectively, and are mounted on a carriage frame 73. In an ordinary carriage, the two wheels are connected by an axle, but it is difficult to install the axle when the distance between the two wheels is long by a crane or in the case of a railway ultra-low floor type vehicle. In such a case, if the motors 71-A and 71-B are connected to the wheels 72-A and 72-B, respectively, and the two motors are operated synchronously, the two wheels can be brought into the same state as being connected by the axle.

  In such a device, when one of the control devices becomes abnormal, the operation method described in the above-described embodiment can be used. In the illustrated example, the motor and the wheel are connected without using a speed reducer, but can be configured using a speed reducer or a connecting shaft, and the installation position and location of the motor are not limited to those illustrated.

  FIG. 8 shows an example in which the present invention is applied to a transfer device or an actuator using an arm. As in FIG. 1, there are provided an A-system device with a code -A added to the end of the code and a B-system device with a code -B added to the end of the code. These A system devices and B system devices are mechanically connected, that is, not connected in terms of driving force, but are operated in synchronism electrically.

In the configuration of the A system, the first AC motor 81-A drives the first arm 83-A, and the second AC motor 82-A at the tip of the first arm 83-A is the second arm 84-A. Drive. The position of the hand 85-A is determined by the movement of the two arms 83-A and 84-A. The mechanism of the B system is the same.
A transported object (not shown) is gripped and transported by the two hands 85-A and 85-B. In FIG. 8, the first motors 81-A and 81-B are electrically operated synchronously, and the second motors 82-A and 82-B are electrically operated synchronously.
Therefore, the A system device and the B system device are electrically operated synchronously and perform the same operation. In this way, the A system apparatus and the B system apparatus cooperate and cooperate to carry.

  As an example of such an apparatus, a conveying apparatus that conveys a workpiece between press machines is assumed. In such a device, it is possible to perform the operation in the above-described abnormality between the motors that are operated in synchronization with each other. In the case of a device having a plurality of sets of motors that are driven synchronously as in this example, an operation is performed in the event of an abnormality between the sets in which an abnormality has occurred in the control device. For example, the speed / position command signal can be changed and given so as to suppress the load on the motor.

In the example illustrated in FIG. 8, the motor and the arm may be connected via a speed reducer or a structure without a speed reducer, and the mounting position of the motor is not limited to the illustration. In FIG. 8, a two-arm type composed of a first arm and a second arm is shown. However, depending on the form of conveyance, one-arm type or three-arm type or more can be applied.
Furthermore, it is not necessary to use an arm type as long as it is a transfer device that operates in synchronization with a plurality of devices. As an example of such an apparatus, for example, a workpiece processed by an upstream press machine is sandwiched by fingers from both sides and conveyed in the downstream direction and sent to the downstream press machine, and then the workpiece is released and returned to the original position. Then, there is a so-called transfer device that repeats the above operation again.

  In addition to the above-mentioned examples, the device that operates the motor in synchronism electrically is applicable not only to the above-mentioned examples but also to various robots other than mobile robots such as door devices, conveyors, industrial machines, various actuators, industrial robots and walking robots. it can.

It is a block diagram which shows schematic structure (normal state) of the drive device of the several electric motor which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the connection state of each part in the case of abnormality occurrence of the drive device which concerns on embodiment same as the above. It is a block diagram which shows the structural example of the state monitoring control part which comprises the drive device which concerns on embodiment same as the above. It is a block diagram which shows the other structural example of the state monitoring control part which comprises the drive device which concerns on embodiment same as the above. It is a block diagram which shows schematic structure (normal state) of the drive device of the several electric motor which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the connection state of each part in the case of abnormality occurrence of the drive device which concerns on embodiment same as the above. It is an example of the drive device which shows the example of application of this invention. It is an example of the other drive device which shows the application example of this invention.

Explanation of symbols

1-A, 1-B AC motor 2-A, 2-B Encoder 3-A, 3-B Converter 4-A, 4-B Speed control unit 5 Speed command unit 6 Status monitoring control unit 11-A, 11 -B Switching Device 21 Switching Device 301-A, 301-B Speed Deviation Unit 302 Deviation Determination Unit 303 Switching Unit 304 Switching Unit 305 Abnormality Detection Unit 501-A, 501-B AC Motor 511-A, 511-B Switching Device 512 Switching device 71-A, 71-B AC motor 72-A, 72-B Wheel 73 Bogie frame 81-A, 81-B First AC motor 82-A, 82-B Second AC motor 83-A, 83- B 1st arm 84-A, 84-B 2nd arm 85-A, 85-B hand

Claims (10)

A plurality of electric motors that are not mechanically coupled to each other;
Information acquisition means for acquiring information related to the operating state of the corresponding motor;
The plurality of electric motors are provided corresponding to each of the plurality of electric motors, and the corresponding electric motors are driven and controlled based on a drive command, and the information acquired by the information acquisition unit is used as feedback information to operate the plurality of electric motors. A plurality of control means having a feedback function for correcting the drive command so as to synchronize,
A plurality of electric motor drive devices comprising:
When a control means among the plurality of control means becomes abnormal, the drive control of the corresponding motor by the abnormal control means is stopped, and the abnormality is made through the sound control means. A drive device for a plurality of motors, wherein drive control is performed so that a plurality of motors including a motor corresponding to the control means are synchronized.   When a certain control means among the plurality of control means becomes abnormal, by switching the drive circuit, the drive control of the corresponding electric motor by the abnormal control means is stopped and the abnormality has occurred. The drive device for a plurality of electric motors according to claim 1, wherein an electric motor corresponding to the control means is connected in parallel with an electric motor that is driven and controlled through the sound control means.   When a certain control means among the plurality of control means becomes abnormal, by switching the drive circuit, the drive control of the corresponding electric motor by the abnormal control means is stopped and the abnormality has occurred. The drive device for a plurality of electric motors according to claim 1, wherein an electric motor corresponding to the control means is connected in series with an electric motor that is driven and controlled via the sound control means.   The sound control is performed by using, as feedback information, information related to the driving state of the motor that has a maximum deviation between the driving command and information related to the driving state of each motor acquired by the information acquisition unit. 4. The drive device for a plurality of electric motors according to claim 1, wherein the unit drives and controls a plurality of electric motors including an electric motor corresponding to the control unit that has become abnormal. 5.   The sound control means includes a plurality of electric motors corresponding to the abnormal control means, using an average value of information related to the operation state of each electric motor acquired by the information acquisition means as feedback information. The drive device for a plurality of motors according to any one of claims 1 to 3, wherein the drive of the motors is controlled.   Based on the deviation between the drive command and the information related to the operating state of each electric motor acquired by the information acquisition means, information related to the operating state of the electric motor with the maximum deviation is used as feedback information. Or the average value of the information related to the operation state of each motor acquired by the information acquisition unit is used as feedback information, and the healthy control unit is based on the selected feedback information. 4. The drive device for a plurality of motors according to claim 1, wherein drive control is performed for a plurality of motors including a motor corresponding to the control means that has become abnormal. 5.   The said healthy control means adds a restriction | limiting to drive control so that load may be reduced, when carrying out drive control of the several electric motor containing the electric motor corresponding to the said control means which became abnormal. A drive device for a plurality of electric motors according to claim 6.   The drive device for a plurality of motors according to any one of claims 1 to 7, wherein the plurality of motors are used as a drive source for wheels.   The plurality of electric motors according to any one of claims 1 to 7, wherein the plurality of electric motors are used as a drive source of the conveying device. A plurality of electric motors that are not mechanically coupled to each other;
Information acquisition means for acquiring information related to the operating state of the corresponding motor;
The plurality of electric motors are provided corresponding to each of the plurality of electric motors, and the corresponding electric motors are driven and controlled based on a drive command, and the information acquired by the information acquisition unit is used as feedback information to operate the plurality of electric motors. A plurality of control means having a feedback function for correcting the drive command so as to synchronize,
A method of controlling a drive device for a plurality of electric motors comprising:
When a control means among the plurality of control means becomes abnormal, the drive control of the corresponding motor by the abnormal control means is stopped, and the abnormality is made through the sound control means. A control method for a drive device for a plurality of motors, wherein drive control is performed so as to synchronize a plurality of motors including a motor corresponding to the control means.