JP5662836B2 - Synchronous control device and synchronous control method - Google Patents

Description

  The present invention relates to synchronous control for a plurality of drive systems.

  A plurality of drive systems may be controlled synchronously. For example, when the object is moved while maintaining the posture by a plurality of drive systems, or the object is moved according to a predetermined trajectory, synchronous control to the drive system is necessary. Regarding synchronous control for two motors, Patent Document 1 discloses that a deviation of a rotational position between motors is fed back to one motor, for example, a motor M2, and a gain for an error from a target position in the motor M2 is reduced. It is described. When the two motors M1 and M2 are attached to the same object, the motors M1 and M2 are synchronized as a result due to the rigidity of the object. Japanese Patent Application Laid-Open No. H10-228688 describes controlling the motor on the advancing side so as to match the motor on the lagging side.

  The synchronization control in Patent Literatures 1 and 2 should be an individual solution method that is effective only in a specific situation, rather than a general solution method for synchronizing two motors. The inventor studied a versatile method for synchronously controlling a plurality of drive systems, and reached the present invention.

JP4323542B JP2002-362709A

  An object of the present invention is to reduce the deviation of a control error between a plurality of drive systems without being limited by the characteristics of the drive systems.

The present invention relates to a synchronous control device that synchronously controls a first drive system and a second drive system having the same characteristics .
A first operation amount for operating the first drive system is generated so as to eliminate the first error between the target position command for the first drive system and the position on the first drive system side. A first PID controller,
A second operation amount for operating the second drive system is generated so as to eliminate the second error between the target position command for the second drive system and the position on the second drive system side. A second PID controller,
A deviation between the first error and the second error is input, and includes a component proportional to the deviation and a component proportional to a time differential value of the deviation, and includes a component based on an integral value of the deviation. A synchronous controller consisting of a PD controller that generates no manipulated variable ;
First control means for controlling the first drive system based on the sum of the first operation amount and the operation amount from the synchronous controller;
Second control means for controlling the second drive system based on the difference between the second operation amount and the operation amount from the synchronous controller ;
The first drive error is ex, the time derivative is ex ', the second error is ey, the time derivative is ey', and the operation amount consisting of Kpxy · ey + Kdxy · ey 'based on the error ey to the first drive system And an operation amount consisting of Kpxy · ex + Kdxy · ex ′ is added to the second drive system based on the error ex, where Kpxy is a control gain to a proportional error, and Kdxy is a control gain to a differential error characterized in that there.

The present invention also provides a synchronous control method for synchronously controlling a first drive system and a second drive system having the same characteristics .
A first operation amount for operating the first drive system is generated so as to eliminate the first error between the target position command for the first drive system and the position on the first drive system side. Step to
A second operation amount for operating the second drive system is generated so as to eliminate the second error between the target position command for the second drive system and the position on the second drive system side. Step to
A deviation between the first error and the second error is input, and includes a component proportional to the deviation and a component proportional to a time differential value of the deviation, and includes a component based on an integral value of the deviation. Generating a non- operating amount by a synchronous controller comprising a PD controller ;
Controlling the first drive system based on the sum of the first operation amount and the operation amount from the synchronous controller;
By performing a step of controlling the second drive system based on the difference between the second operation amount and the operation amount from the synchronous controller ,
The first drive error is ex, the time derivative is ex ', the second error is ey, the time derivative is ey', and the operation amount consisting of Kpxy · ey + Kdxy · ey 'based on the error ey to the first drive system And an operation amount of Kpxy · ex + Kdxy · ex ′ is added to the second drive system based on the error ex . Here, Kpxy is a control gain for proportional error, and Kdxy is a control gain for differential error.

  In the present invention, as a general-purpose synchronous control that does not select the type of drive system or the like, a deviation in control error between a plurality of drive systems can be reduced. Moreover, priority is given to controlling each drive system according to a target value or priority is given to synchronization between a plurality of drive systems, depending on the ratio between the first and second manipulated variables and the manipulated variable from the synchronization controller. Can be adjusted. In this specification, the description related to the synchronization control device also applies to the synchronization control method as it is, and conversely, the description related to the synchronization control method also applies to the synchronization control device as it is. In addition, description such as “based on the first operation amount and the operation amount from the synchronous controller” means that, for example, the sum of these operation amounts is used, but is not limited thereto. The drive system is, for example, an electric motor, but is not limited thereto.

In the present invention, the synchronous control device outputs an operation amount composed of a component proportional to the deviation and a component proportional to the time differential value of the deviation to the first and second control means. In this way, the deviation can be eliminated by the component proportional to the deviation, the time differential value of the deviation can be eliminated by the component proportional to the time differential value of the deviation, and the absolute value of the deviation can be kept small as a whole.

Particularly preferably, the first drive system and the second drive system have the same performance and are arranged symmetrically with respect to the object, and the first control means and the second control means are provided from the synchronous controller. On the other hand, an operation amount obtained by reversing the positive and negative signs is input. The input of an operation amount obtained by reversing the positive / negative sign includes not only reversing the sign by the synchronous controller but also reversing the sign by the first control means or the second control means. When the first drive system and the second drive system have the same performance and are arranged symmetrically with respect to the object, the first control means and the second control means are used as the operation amount for eliminating the deviation. And the sign may be reversed. In other words, since one operation amount is used in common by changing the sign in both the first control means and the second control means, generation of an operation amount for eliminating the deviation is simplified.

Example block diagram Block diagram of synchronous controller of embodiment The figure which represents the synchronous control in an Example with a matrix Block diagram of a reference example using multiple synchronous controllers Block diagram of a modification for synchronously controlling three motors The flowchart which shows the synchronous control method of an Example Diagram showing target position of motor in experiment Fig. 7 shows the control results when a disturbance is applied to the second motor side at the target position in Fig. 7. 1) shows the deviation from the target position of each motor when two motors are controlled synchronously. The deviation from the target position of each motor when the synchronous control is not performed, and 3) shows the deviation between the motors. The control result when a periodic disturbance is given to the second motor is shown, the error from the target position of each motor when the two motors are synchronously controlled, and the target of each motor when the synchronous control is not performed An error from the position and a deviation between the motors when the synchronous control is not performed are shown.

  In the following, an optimum embodiment for carrying out the present invention will be shown. The scope of the present invention should be determined according to the understanding of those skilled in the art based on the description of the scope of the claims, taking into account the description of the specification and well-known techniques in this field.

1 to 9 show an embodiment and its modifications. FIG. 1 shows the configuration of a synchronous control apparatus according to an embodiment, wherein M1 and M2 are servo controlled motors to be controlled, 2 is a target position generator, and two target positions xr and yr as a function of time, for example. Occur. Symbols such as x, y, and z do not represent coordinates in an orthogonal coordinate system or the like, but represent a position on the motor M1 side as x and a position on the motor M2 side as y. The subscript r represents the target value. Here, the motors M1 and M2 are controlled to operate according to the target positions xr and yr, but the motors M1 and M2 may be controlled to operate according to the target speed or target torque instead of the target position. The adder / subtractor 20 obtains an error ex between the target position xr and the actual position x, and inputs it to the PID controller 4 to obtain an output ux as an operation amount. Similarly, the adder / subtractor 21 obtains an error ey between the target position yr and the actual position y and inputs it to the PID controller 5 to obtain an output uy as an operation amount. PID controllers 4 and 5 are well known. The control target is not limited to a motor, and may be a pneumatic device, a hydraulic device, an internal combustion engine, or the like.

  The deviation α between the errors ex and ey (α = ex−ey) is obtained by the adder / subtractor 30 and input to the synchronous controller 10 to obtain the output β. The adder / subtractor 40 adds the output ux and the output β to the manipulated variable vx. Controls the motor M1. Similarly, the motor M2 is controlled by the operation amount vy obtained by subtracting the output β from the output ux by the adder / subtractor 41. Reference numeral 45 is a current amplifier for controlling the motor M1, and 46 is a current amplifier for controlling the motor M2. Further, the positions x and y may be obtained by an encoder of the motors M1 and M2, or may be obtained by a position sensor such as a laser distance meter or a linear scale.

FIG. 2 shows the structure of the synchronous controller 10. The integrator 32 integrates the deviation α, and the differentiator 33 differentiates the deviation α. An operational amount proportional to the integral value of the deviation α is generated by the amplifier 34, an operational amount proportional to the deviation α is generated by the amplifier 35, and an operational amount proportional to the differential value of the deviation α is generated by the amplifier 36. These outputs are added by the adder / subtractor 37 to obtain the output β of the synchronous controller 10. Inverting amplifier 38 reverses the sign of β and outputs -β. In the embodiment, the controller 10 is described as being realized by an analog circuit or the like. However, this is for the sake of simplicity, and the controller 10 and the adder / subtractor are configured by a microcomputer, DSP (digital signal processor), or the like. 20, 21, etc. may be realized. However, in the embodiment, the integrator 32 and the amplifier 34 are not provided.

Although slightly different from FIG. 2, an output proportional to the deviation α and an output proportional to the differential value of the deviation α are added. Although an output proportional to the deviation α, an output proportional to the differential value, and an output proportional to the integral value may be added, such a thing is not included in the scope of claims. 1 and 2, when the control gain of the PID controllers 4 and 5 is increased and the gain of the synchronous controller 10 (that is, the gains of the amplifiers 34 to 36) is reduced, the motor is more effective than the synchronization of the motors M1 and M2. The control emphasizes that M1 and M2 operate faithfully to the respective target positions xr and yr. Conversely, if the control gain of the PID controllers 4 and 5 is reduced and the gain of the synchronization controller 10 (that is, the gains of the amplifiers 34 to 36) is increased, the control emphasizing synchronization is performed. When the gain of the amplifier 34 is further increased, the offset between the outputs of the motors M1 and M2 can be reduced. When the gain of the amplifier 35 is increased, the proportional control for eliminating the deviation α is strengthened. Further, when the gain of the amplifier 36 is increased, the synchronous control based on the rate of change of the deviation α becomes stronger.

FIG. 3 shows the control in the embodiment by a matrix, and s is a parameter in Laplace transform. The off-diagonal term in each matrix represents a synchronous gain of the motors M1 and M2, that is, a control gain for reducing the deviation α between the errors ex and ey. The diagonal term represents not the synchronization between the motors M1 and M2, but the control gain for reducing the errors ex and ey themselves. When the motors M1 and M2 are the same and the motor M1 and the motor M2 are arranged symmetrically with respect to the object, each matrix is a symmetric matrix, and Kpxy = Kpyx,
It is preferable that Kdxy = Kdyx, and Kixy = Kiyx = 0. Kixy = Kiyx = 0 means that the same motors M1 and M2 are arranged symmetrically with respect to the object, so that a steady deviation (offset) is originally present unless some steady external force acts between them. Because it is small.

For example, first and second members are provided on both the left and right sides of the object, the motor M1 drives the first member, the motor M2 drives the second member, and the object moves along a predetermined trajectory. It may be important to do that. In this case, the deviation α corresponds to the deviation from the locus. A reference example for such a case is shown in FIG. In this case, the motors M1 and M2 are generally not the same motor. In addition, since the drags received by the motors M1 and M2 from the object and the inertia of the objects are not common, separate synchronous controllers 10 and 10 'are provided. Further, in order to properly normalize the magnitudes of the errors ex and ey, the error ey is amplified by the amplifier 24, for example. If the reference example of FIG. 4 is considered by FIG. 3 matrix, each matrix is an asymmetric matrix and all four components of each matrix differ. In other respects, the reference example of FIG. 4 is equivalent to the embodiment of FIGS. However, the reference example of FIG. 4 is not included in the scope of claims.

  FIG. 5 shows a modification in which three motors M1, M2, and M3 are synchronously controlled, and the same applies to the case of controlling four or more motors. The motors M1 and M2 are controlled in the same manner as in FIG. 1, the deviation between the target position zr and the actual position z is obtained by the adder / subtractor 22 with respect to the motor M3, and the error ez is eliminated by a controller such as the PID controller 6. To generate output uz. Outputs .beta.xy, .beta.yz, and .beta.zx for eliminating the three types of deviations .alpha.xy = ex-ey, .alpha.yz = ey-ez, and .alpha.zx = ez-ex are generated by the synchronous controllers 10, 11, and 12. Outputs βxy, βyz, βzx are output by adders / subtractors 40 ', 41', 42 '. The motors M1, M2, and M3 are controlled via the current amplifiers 45 to 47 by the operation amounts vx, vy, and vz added and subtracted from uy and uz. The structure of the synchronization controllers 11 and 12 is the same as that of the synchronization controller 10. When the motors M1, M2, M3 are not the same, two synchronous controllers 10, 11, 12 are provided instead of the two synchronous controllers 10, 11, 12 as shown in FIG. It is preferable to obtain a deviation by providing a synchronous controller and normalizing the magnitudes of the errors ex, ey, and ez appropriately.

  FIG. 6 shows a synchronization control method in the embodiment of FIGS. In step 1, target positions xr, yr, etc. are output from the target position generator (step 1). For the target position xr, yr, data from the start to the end of the operation may be created in advance, and xr, yr may be output for each control cycle. Alternatively, the target positions xr and yr may be generated for each control cycle. Further, a target speed or a target torque may be output instead of the target position.

  In step 2, the manipulated variables ux and uy are generated by PID control or the like based on the errors ex and ey between the target position xr, yr and the actual position x, y. In step 3, an operation amount β is generated by PD control or proportional control based on the deviation α (α = ex-ey). The motor M1 is controlled by ux + β, and the motor M2 is controlled by uy−β (step 4). The above steps are repeated until the operation is completed (step 5).

  FIG. 8 shows a control result according to the embodiment of FIG. 1, and the same motors M1 and M2 drive separate but equivalent loads. According to the position command in FIG. M2 was operated and disturbance was applied only to the motor M2. The control result when the synchronous controller 10 is not provided is asynchronous control, and the control in the embodiment is synchronous control. In both synchronous control and asynchronous control, Kpxx = Kpyy = 3.76, Kixx = Kipyy = 5, and Kdxx = Kdyy = 0.135. In the synchronous control, Kpxy = Kpyx = −1.23, Kdxy = Kdyx = −0.12, and Kixy = Kiyx = 0 as non-diagonal terms. In the asynchronous control, all values of non-diagonal terms are zero. In the synchronous control, the maximum absolute value of the deviation α is reduced to about 2/3 that in the asynchronous control, and the maximum absolute value of the error on the motor M2 side is also smaller than that in the asynchronous control.

  In the experiment of FIG. 9, a periodic disturbance (time 1 second to 8 seconds) was applied only to the motor M2 in the same system used in the experiment of FIG. The control gain is the same as in FIG. In the synchronous control, the motor M1 operates so as to be synchronized with the motor M2, in other words, to have the same error as the motor M2, and the deviation is smaller than that of the asynchronous control.

The embodiment has the following characteristics.
1) Multiple motors can be controlled synchronously. By tuning the gain for synchronous control such as Kpxy and Kdxy, it is possible to adjust whether each motor operates faithfully to the command or to reduce the deviation between a plurality of motors.
2) The control method is versatile and can be applied to any target.
3) Can easily be extended to synchronous control of 3 or more motors.
4) Applicable to drive systems other than motors such as hydraulic, pneumatic and internal combustion engines.
5) When two motors with the same characteristics are arranged symmetrically with respect to the target, the off-diagonal term in integral gain can be set to 0, and the off-diagonal terms in proportional gain and differential gain are Kpxy = Kpyx, Kdxy = Can be simplified as Kdyx.
6) PID controllers 4, 5, 6 etc. can be changed to PD controllers and other arbitrary controllers, and the control method is not chosen for the base asynchronous control part.

2 Target position generators 4-6 PID controllers 10-12 Synchronous controllers 20-22 Adder / subtractor 24 Amplifier 30, 37 Adder / subtractor 32 Integrator 33 Differentiator 34-36 Amplifier 38 Inverting amplifier 40, 41 Adder / subtractor 40, 41 Adder / Subtractor 45-47 Current Amplifier

M1-M3 motor

Claims (2)

In the synchronous control device for synchronously controlling the first drive system and the second drive system having the same characteristics ,
A first operation amount for operating the first drive system is generated so as to eliminate the first error between the target position command for the first drive system and the position on the first drive system side. A first PID controller,
A second operation amount for operating the second drive system is generated so as to eliminate the second error between the target position command for the second drive system and the position on the second drive system side. A second PID controller,
A deviation between the first error and the second error is input, and includes a component proportional to the deviation and a component proportional to a time differential value of the deviation, and includes a component based on an integral value of the deviation. A synchronous controller consisting of a PD controller that generates no manipulated variable ;
First control means for controlling the first drive system based on the sum of the first operation amount and the operation amount from the synchronous controller;
Second control means for controlling the second drive system based on the difference between the second operation amount and the operation amount from the synchronous controller ;
The first drive error is ex, the time derivative is ex ', the second error is ey, the time derivative is ey', and the operation amount consisting of Kpxy · ey + Kdxy · ey 'based on the error ey to the first drive system And an operation amount consisting of Kpxy · ex + Kdxy · ex ′ is added to the second drive system based on the error ex, where Kpxy is a control gain to a proportional error, and Kdxy is a control gain to a differential error A synchronization control device, characterized in that there is. In a synchronous control method for synchronously controlling a first drive system and a second drive system having the same characteristics ,
A first operation amount for operating the first drive system is generated so as to eliminate the first error between the target position command for the first drive system and the position on the first drive system side. Step to
A second operation amount for operating the second drive system is generated so as to eliminate the second error between the target position command for the second drive system and the position on the second drive system side. Step to
A deviation between the first error and the second error is input, and includes a component proportional to the deviation and a component proportional to a time differential value of the deviation, and includes a component based on an integral value of the deviation. Generating a non- operating amount by a synchronous controller comprising a PD controller ;
Controlling the first drive system based on the sum of the first operation amount and the operation amount from the synchronous controller;
By performing a step of controlling the second drive system based on the difference between the second operation amount and the operation amount from the synchronous controller ,
The first drive error is ex, the time derivative is ex ', the second error is ey, the time derivative is ey', and the operation amount consisting of Kpxy · ey + Kdxy · ey 'based on the error ey to the first drive system And an operation amount of Kpxy · ex + Kdxy · ex ′ is added to the second drive system based on the error ex .
(Here, Kpxy is a control gain for proportional error, and Kdxy is a control gain for differential error)

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