JP4678475B2 - Electric motor control device - Google Patents

Description

  The present invention relates to a control device that performs synchronous control of a plurality of motors having different characteristics and / or loads, and particularly relates to a motor control device that can simplify arithmetic processing for control.

  Conventionally, regarding a control device for a vehicle opening / closing body that can be used for a hood or a roof panel of a convertible vehicle, two electric motors having the same characteristics and the same load are arranged on the left and right sides, and the speeds of these two electric motors are synchronized. There is known a control device that performs control. This control device includes a rotation sensor that generates a pulse signal synchronized with the rotation of the motors in order to synchronously control the speeds of the two motors, and the current position and current position of the two motors are determined by signals from the rotation sensors. Calculate the speed. Then, a target position after a unit time is calculated from the average position of the current positions of the two motors and a predetermined target speed of the motors, and a unit time after the current positions and the current speeds of the two motors. Calculate the predicted position of each motor. Next, the target position after the unit time and the predicted position of each motor are compared to calculate the control position of each motor after the unit time, and the speed control of each motor is performed accordingly (for example, Patent Document 1). reference).

JP 2001-119976 A (page 2-3, FIG. 1)

  However, in such a conventional control device, it is suitable for synchronous control of a plurality of motors having the same characteristics and load. However, when synchronous control of a plurality of motors having different characteristics or loads is performed. Since it is necessary to perform different arithmetic processing depending on each electric motor for the calculation of the predicted position, speed control, etc., the calculation burden of the control device increases in proportion to the number of electric motors. Therefore, when performing synchronous control of a large number of motors having different characteristics and / or loads, it is required to use a high-performance arithmetic processing unit, which causes a problem of cost increase.

  The present invention has been made in view of the above problems, and its purpose is to simplify arithmetic processing for control when performing synchronous control of a plurality of motors having different characteristics and / or loads. The object is to provide an electric motor control device capable of reducing the cost of the device.

The first characteristic feature of the motor control apparatus according to the present invention for achieving the above object, a detection unit for outputting it as actual operation amount information by detecting the actual operation amount of the electric motor, the plurality of electric motors By multiplying each theoretical operation amount at an arbitrary point in time, the actual operation amount information of each motor is multiplied by a conversion coefficient that takes a value such that the multiplication results coincide with each other. a conversion unit for converting each of the reference operation amount information is, based on the reference operation amount information of the electric motor, in that it comprises a control unit for controlling the operation of each electric motor.

  According to the first feature configuration, when performing synchronous control of a plurality of motors having different characteristics and / or loads, the operation amounts of the plurality of motors are converted into a standard scale as a reference operation amount. Since the operation control of each motor is performed based on the operation amount, the control unit can perform the same calculation process as if the operation control of a plurality of motors having the same characteristics and load is performed. Can be simplified and the cost of the apparatus can be reduced.

  A second characteristic configuration of the motor control device according to the present invention is that the conversion coefficient is a constant determined based on a ratio of theoretical operation amounts of the plurality of motors.

  According to the second feature configuration, the conversion coefficient used in the conversion unit can be determined in advance at the design stage of the apparatus.

  According to a third characteristic configuration of the motor control device according to the present invention, the control unit compares the reference operation amount information of the plurality of motors, reduces the speed of the motor whose reference operation amount is advanced, This is to increase the speed of the motor whose operation amount is delayed.

  According to the third characteristic configuration, it is determined whether the operation amount of each motor is delayed or advanced compared to the operation amounts of the other motors based on the standard operation amount that is a unified measure, and based on the determination. Since operation control of each electric motor is performed, it is not necessary to perform arithmetic processing corresponding to each of a plurality of electric motors having different characteristics or loads, and the arithmetic processing for control can be further simplified. it can.

  The fourth characteristic configuration of the motor control device according to the present invention is that a period of time during which the operation of the operating motor is not stopped or the operation of the stopped motor is not started is defined as one control region, and a plurality of operating units are operated for each control region. The point is that the operation is controlled for the electric motor.

  According to the fourth feature configuration, even when there are some of the plurality of electric motors having different operation start timing and operation stop timing, the above-described first to third are intended for the plurality of operating motors. The synchronous control can be performed by the same simple process as in the case of the feature configuration.

  Hereinafter, an embodiment in which the motor control device according to the present invention is applied to synchronous control of a drive motor for a seat 1 in a welfare vehicle 2 that can swing the seat 1 out of the vehicle or store it in the vehicle interior. Will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a movement mode of the seat 1 of the welfare vehicle 2 according to the present embodiment, and FIG. 2 is a functional block diagram of the motor control device according to the present embodiment.

  As shown in FIG. 1, the seat 1 of the welfare vehicle 2 according to this embodiment hits a door, a vehicle body, or the like by simultaneously operating in three directions of a rotation direction A, a front / rear slide direction B, and an inner / outer slide direction C. The vehicle can be swung out to the outside of the vehicle or stored inside the vehicle through an appropriate locus E having no gap. Thus, in order to move the seat 1 simultaneously at an appropriate speed in each of the three directions, in the present embodiment, as shown in FIG. 2, the first motor M1 and the second motor are used for each operation in the three directions. Three electric motors M2 and a third electric motor M3 are provided. That is, the first motor M1 is responsible for the operation of the seat 1 in the rotational direction A, the second motor M2 is the forward / backward sliding direction B, and the third motor M3 is the inner / outer sliding direction C. Make it work.

  The first electric motor M1, the second electric motor M2, and the third electric motor M3 have different operation amounts from the start to the end of the operation when the seat 1 is moved out or stored, and the operation speed and load during the operation are also different. That is, the first electric motor M1, the second electric motor M2, and the third electric motor M3 have different loads, and electric motors having different characteristics are used accordingly.

  Further, as shown in FIG. 2, the first electric motor M1, the second electric motor M2, and the third electric motor M3 have a first sensor S1 that outputs a pulse signal in accordance with an operation amount (here, an amount of rotation), and a first sensor S1. The number of pulse signals output from the two sensors S2 and the third sensor S3 and the first sensor S1, the second sensor S2, and the third sensor S3 are integrated to calculate the actual number of pulses, and the actual number of pulses is calculated. A first integrator I1, a second integrator I2, and a third integrator I3 that output information are provided. This “actual pulse number” represents the actual operation amount from the start of operation of each of the motors M1 to M3 to the present time, and corresponds to the “actual operation amount” in the present invention. Therefore, “actual pulse number information” corresponds to “actual operation amount information” in the present invention. In the present embodiment, the first sensor S1, the second sensor S2, the third sensor S3, the first integrator I1, the second integrator I2, and the third integrator I3 constitute the detection unit 3. Yes. In the following, the total operation amount, that is, the total number of pulses of the electric motors M1 to M3 from the start to the end of the operation when the seat 1 is moved out or stored, the first electric motor M1 is 250 pulses, the second electric motor M2 is 500 pulses, The case where the third electric motor M3 has 1000 pulses will be described as an example. Here, in order to simplify the description, the total number of pulses of each of the motors M1 to M3 is set to a relatively simple number of pulses, and the ratio of the total operation amount between the motors M1 to M3 is as simple as 1: 2: 4. I try to be something.

  The actual pulse number information output from the first integrator I1, the second integrator I2, and the third integrator I3 is input to the conversion unit 4. And in the conversion part 4, it converts so that the theoretical pulse number in the arbitrary time of the 1st electric motor M1, the 2nd electric motor M2, and the 3rd electric motor M3 may correspond with respect to the actual pulse number information of each electric motor M1-M3. Each of the conversion coefficients a1, a2, and a3 is multiplied to convert the information into reference pulse number information of each of the electric motors M1 to M3 and output the information. This “reference pulse number information” corresponds to “reference operation amount information” in the present invention. Here, the “theoretical pulse number” is a pulse at each time point of each of the first motor M1, the second motor M2, and the third motor M3 when each of the motors M1 to M3 performs an ideal operation as designed. The number of theoretical pulses corresponds to the “theoretical operation amount” in the present invention. The conversion coefficients a1, a2, and a3 are multiplied by the respective theoretical pulse numbers at arbitrary points in time of the first electric motor M1, the second electric motor M2, and the third electric motor M3. It is a coefficient that takes such a value. Therefore, in the present embodiment, the conversion coefficients a1 to a3 are constants determined based on the ratio of the number of theoretical pulses (theoretical operation amount) of the electric motors M1 to M3 to be controlled. That is, when the ratio of the total number of pulses of the first electric motor M1, the second electric motor M2, and the third electric motor M3 is 1: 2: 4, and all the electric motors M1 to M3 perform an ideal operation as designed. Since the ratio of the number of pulses of each of the motors M1 to M3 does not change at any time during operation, the ratio of the theoretical number of pulses is 1: 2: 4 at all times during the operation of each of the motors M1 to M3. . Therefore, if the ratio of the conversion coefficients a1, a2, and a3 is set to the inverse ratio 4: 2: 1 of the ratio 1: 2: 4 of the theoretical pulse numbers of the electric motors M1 to M3, any electric motor M1 to M3 The results obtained by multiplying the respective theoretical pulse numbers at the time by the conversion coefficients a1, a2, and a3 coincide with each other. Therefore, here, the conversion coefficients are a1 = 4, a2 = 2, and a3 = 1. These conversion coefficients a1 to a3 are stored in the storage unit 5 and are read out during the conversion process in the conversion unit 4.

  The conversion process from the actual pulse number information of each of the motors M1 to M3 in the conversion unit 4 to the reference pulse number information will be specifically described with reference to FIG. In FIG. 3, the three axes of the M1, M2, and M3 axes, which are the axes representing the actual pulse numbers of the first electric motor M1, the second electric motor M2, and the third electric motor M3, are set as the horizontal axis (x axis). The axis representing the reference pulse number of the first electric motor M1, the second electric motor M2 and the third electric motor M3 is taken as the vertical axis (y-axis), and the actual pulse number information of each electric motor M1 to M3 is referred to by the conversion coefficients a1, a2 and a3. It is a graph showing the conversion function at the time of converting into pulse number information. As shown in this figure, if the actual pulse number of each motor M1 to M3 is x and the reference pulse number of each motor M1 to M3 is y, the conversion functions of each motor M1 to M3 are “y = a1x”, “ y = a2x ”and“ y = a3x ”. Here, since the conversion coefficients are a1 = 4, a2 = 2, and a3 = 1, the conversion function to the reference pulse number information in the conversion unit 4 is specifically “y = 4x ”,“ y = 2x ”for the second motor M2, and“ y = x ”for the third motor M3. For example, when the actual number of pulses of the first electric motor M1 at a certain time is “160”, the actual number of pulses of the second electric motor M2 is “285”, and the actual number of pulses of the third electric motor M3 is “600”, the conversion unit 4 The number of reference pulses of each of the electric motors M1 to M3 after the conversion is “640” for the first electric motor M1, “570” for the second electric motor M2, and “600” for the third electric motor M3. Here, when all the motors M1 to M3 perform an ideal operation as designed, that is, when the actual pulse number of each motor M1 to M3 is equal to the theoretical pulse number, the reference of all the motors M1 to M3 Since the number of pulses matches, the difference in the number of reference pulses of each of the electric motors M1 to M3 can be considered as a control error. Therefore, by converting the actual pulse number information of each of the motors M1 to M3 into the reference pulse number information in this way, the control unit 6 can easily control errors by only comparing the reference pulse number which is a unified measure. Can be detected.

  In the control part 6, based on the reference | standard pulse number information of each electric motor M1-M3, operation control of each electric motor M1-M3 is performed so that the above control errors may be eliminated. That is, the control unit 6 compares the reference pulse number information of each of the electric motors M1 to M3, reduces the speed of the motor with the advanced reference pulse number, and increases the speed of the motor with the delayed reference pulse number. Do. Such a control algorithm in the control unit 6 is stored in the storage unit 5.

  FIG. 4 is an explanatory diagram illustrating a method for controlling the operation of each of the motors M1 to M3 by the control unit 6 according to the present embodiment. As shown in this figure, in the present embodiment, the controller 6 first calculates an average value Ave of the current reference pulse numbers of the electric motors M1 to M3. For example, as illustrated in FIG. 3 described above, the current reference pulse numbers of the electric motors M1 to M3 are “640” for the first electric motor M1, “570” for the second electric motor M2, and “570” for the third electric motor M3. In the case of “600”, the average value Ave is “Ave = 603.333...”. Then, the reference pulse number is advanced from the average value Ave, that is, the speed v1 of the first electric motor M1, which is an electric motor having a large reference pulse number, is decreased, and the reference pulse number is delayed from the average value Ave. That is, control is performed to increase the speed v2 of the second motor M2 and the speed v3 of the third motor M3, which are motors having a small reference pulse number. In order to prevent the motor from causing hunting, a certain range of allowable error area is set before and after the average value Ave, and control is performed so as not to change the speed of the motor having the reference pulse number in the allowable error area. In some cases. In the present embodiment, the speeds v1 to v3 of the electric motors M1 to M3 are controlled by PWM (Pulse Width Modulation) control, so that the speeds v1 to v3 of the electric motors M1 to M3 are increased or decreased. Control is performed by increasing or decreasing the duty ratio.

  As a method of increasing or decreasing the duty ratio for controlling the increase or decrease of the speeds v1 to v3 of the motors M1 to M3, for example, the duty ratio is increased or decreased by several percent every short time of about several tens of ms. It is possible to do this. Accordingly, the speeds v1 to v3 of the electric motors M1 to M3 are increased or decreased every time the average value Ave is calculated, and the speed control is performed so that the reference pulse number of the electric motors M1 to M3 approaches the average value Ave. The reference pulse numbers of all the motors M1 to M3 can be converged to the vicinity of the average value Ave without rapidly changing the speed. Further, for example, the increase or decrease of the speeds v1 to v3 may be controlled by increasing or decreasing the duty ratio with a magnitude proportional to the difference from the average value Ave of the reference pulse numbers of the electric motors M1 to M3. Is possible. The initial duty ratio at the start of operation of each of the motors M1 to M3 is stored in the storage unit 5.

  In the above embodiment, the case where the first electric motor M1, the second electric motor M2, and the third electric motor M3 start and stop at the same time has been described. However, in an actual electric motor control device, there are a plurality of electric motors. In some cases, the start time and stop time of the operation are different, and some motors may start to operate with a delay, or may be controlled to stop the operation first. When such control is performed, the operation of the operating motor is stopped or the operation of the stopped motor is not started as one control area, and the operation is performed for a plurality of operating motors for each control area. Take control. By doing so, even if there are those in which the operation start timing and the operation stop timing are different among the plurality of electric motors, only the plurality of electric motors in operation are targeted, which is completely different from the above embodiment. Control can be performed by a control device having a similar configuration.

  The present invention is suitable for a control device for performing synchronous control of a plurality of electric motors having different characteristics and / or loads, such as when driving in a plurality of directions by electric motors corresponding to the respective directions. Can be used.

The schematic diagram which shows the aspect of the movement of the seat of the welfare vehicle which is an example of the application object of the control apparatus of the electric motor which concerns on this embodiment. Functional block diagram of the motor control device according to the present embodiment The graph showing the conversion function at the time of converting real pulse number information into reference | standard pulse number information in the conversion part of the control apparatus of the electric motor which concerns on this embodiment Explanatory drawing which shows the method of operation control of each electric motor by the control part of the control apparatus of the electric motor which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Detection part 4 Conversion part 6 Control part M1 1st electric motor M2 2nd electric motor M3 3rd electric motor S1, S2, S3 Sensor I1, I2, I3 Accumulator a1, a2, a3 Conversion coefficient

Claims (4)

A control device that performs synchronous control of a plurality of electric motors having different one or both of characteristics and loads,
A detection unit that detects the actual operation amount of each motor and outputs it as actual operation amount information;
By multiplying each theoretical operation amount at an arbitrary point in time of the plurality of electric motors, conversion coefficients that take values such that the multiplied results coincide with each other are respectively obtained for the actual operation amount information of each electric motor. A conversion unit that multiplies and converts the reference movement amount information, which is a unified scale, and outputs the information ,
A motor control device comprising: a control unit that performs operation control of each motor based on the reference operation amount information of each motor.   The motor control device according to claim 1, wherein the conversion coefficient is a constant determined based on a ratio of theoretical operation amounts of the plurality of motors.   2. The control unit compares the reference operation amount information of the plurality of electric motors, reduces the speed of the motor whose reference operation amount is advanced, and increases the speed of the motor whose reference operation amount is delayed. Or the control apparatus of the electric motor of 2.   The operation control is performed for a plurality of motors that are operating in each control region, with a period of time during which the operation of the motor that is operating is stopped or the operation of the stopped motor is not started as one control region. The motor control device according to claim 1.

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