JP2002163006A - Controller and method for controlling electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that times for restrain of vibration of a machine base, regulation of a gain in a controller and the like are required since the vibration of the machine base is generated by steep driving force for moving a table. SOLUTION: A predistorter la inside an electric motor controller is provided with a simulation position controller 13 for generating a simulation speed command, a simulative adaptive speed controller 15 of which the gain is regulated adaptively by a deviation e(t), a mathematical model 17 for inputting a predistortion torque command from the adaptive speed controller 15 to output a simulation position detecting signal, and a simulation speed computing element 19 for transmitting the simulation speed detecting signal from the simulation position detecting signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device used in a machine tool such as an electronic circuit board assembly process and a machining center.

[0002]

2. Description of the Related Art A conventional example of a motor control device used for positioning control will be described with reference to FIG. FIG. 4 shows an example of a positioning control configuration in only one axis direction. 4, reference numeral 41 denotes an electric motor, 42 denotes an electric motor position detector, 43 denotes a work, 44 denotes a table, 45 denotes a machine base (platen), 46 denotes an electric motor control device, 47 denotes an electric motor drive signal, and 48 denotes an electric motor position detection signal. , 49 is a table position detection signal, 50 is a speed reducer, 51 is a ball screw, 52 is a nut supporting one end of the ball screw, 53 is an anti-vibration pad, and 54 is a position target value signal. In FIG. 4, a position target value signal 54 is given to a motor control device 46, and the motor control device uses the motor position detection signal 42 and the table position detection signal 49 to determine the position of a table on which a work to be processed is mounted. The control is performed so as to match the target value. FIG. 5 is a block diagram showing an example of a control configuration in the motor control device 46. In FIG. 5, 56 is a table position compensator, and 55 is a motor position compensator. The table position compensator 56 evaluates the table position detection signal 49 and the table position target value, and determines an output value to the motor position compensator 55. The motor position compensator 55 evaluates the motor position detection signal 48 and the output value of the table position compensator 56, and outputs a drive signal for the motor. Many conventional controllers perform table positioning by performing motor positioning using only the motor position detection signal. In the above example, a ball screw is taken as an example of the table drive mechanism. However, in recent years, examples of apparatuses using a linear motor as a drive system have been increasing. In this case, the controller is generally configured using up to the table position detection signal in many cases. As described above, the work fixed on the table is matched with a desired target position by matching the table position with the target value.

[0003]

However, in recent years, in order to shorten the table moving time in order to improve the productivity, the table moving speed has become steep, and the driving force for driving the table has increased. For this reason, a steep propulsion force is generated, and a vibration component is induced by a spring element in the equipment, which has not been a problem in the related art, and a phenomenon occurs in which positioning accuracy is adversely affected. One example is machine vibration. Machine vibration means that the spring element between the machine and the ground, which had not been a problem at the time of gentle acceleration / deceleration commands, increased the propulsive force of the table, increasing the reaction force from the table to the machine, causing the machine to shake. This is the phenomenon. This phenomenon is particularly remarkable when a linear motor is used for the drive system of the table. In general, this machine vibration has different displacement and phase between the table and the machine, so even if the table driving operation is finished, the machine vibration remains, so the table position fluctuates and stops after the table starts driving. There was a problem that it was not possible to shorten the time required to complete. In addition, when measuring the displacement of the machine base, the entire equipment becomes large and costly.
The reality was poor. As a control method for such a system having multiple vibration modes, the affected vibration mode changes according to the position command state (acceleration / deceleration, constant speed feed, after command issuance, etc.). There is a means for switching the gain according to the state of the position command and the state of the detection signal, but the timing for performing the gain switching and the gain value at the time of switching must be determined in advance by trial and error, which requires a great deal of adjustment. Time was needed. Therefore, the present invention is intended to suppress a plurality of vibration modes satisfactorily, improve the positioning performance, and greatly shorten the gain adjustment time without newly improving the equipment.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is to position an electric motor such that equipment having a plurality of vibration modes by a plurality of spring elements is connected to an electric motor so as to perform a desired movement. A motor control device, comprising a pre-compensator to which a position command to the equipment is input, wherein the pre-compensator is a mathematical model based on a motion equation of the equipment, a position command to the equipment, and A simulated position controller for generating a simulated speed command from a deviation from either the simulated machine position detection signal or the simulated motor position detection signal in the mathematical model, and the simulated machine position detection signal or the simulated motor position detection signal in the mathematical model A simulated speed calculator for generating a simulated speed detection signal;
Speed calculation for outputting a speed detection signal of a machine or a motor speed detection signal using a speed command and a machine position detection signal or a motor position detection signal in equipment to determine a pre-compensation torque command to the mathematical model. A simulated adaptive speed controller in which a gain is adaptively adjusted using a deviation from a speed detection signal output from a motor, and a simulated machine position detection signal or a simulated motor position detection output from the mathematical model. A position controller that generates a main speed command using any one of a signal and a machine position detection signal or a motor position detection signal in the equipment; and adding the main speed command and the simulated speed command to the speed command. And a speed command output from the speed command adder and a machine speed detection signal in the facility output from the speed calculator. Based on a deviation between the motor speed detection signal, a torque command is input to the motor from the pre-compensation torque command and speed controller for generating a feedback torque command and the feedback torque command

[0005]

(Equation 6)

[0006] It is an object of the present invention to provide a motor control device characterized by comprising a torque command adder determined in step (1) and a power converter for inputting the torque command and supplying appropriate electric power to the motor. Here, the simulated adaptive speed controller is expressed by the following equation.

[0007]

(Equation 7)

[0008] Further, in a motor control device for positioning a motor so that a facility in which a motor is connected to a machine having a plurality of vibration modes by a plurality of spring elements performs a desired movement, a front position where a position command to the facility is input. The pre-compensator comprising a compensator generates a simulated speed command from a deviation between a mathematical model based on the equation of motion of the equipment, a position command to the equipment, and a simulated machine position detection signal in the mathematical model. A simulated position controller, a simulated speed calculator for generating a simulated machine speed detection signal from a simulated machine position detection signal in the mathematical model, and a speed command to determine a pre-compensated main torque command to the mathematical model. A simulated adaptive speed controller that adaptively determines a gain using a deviation from a motor speed detection signal output from a speed calculator using a motor position detection signal; In order to determine the simulated auxiliary torque command to the mathematical model, the gain is adaptively determined using the simulated torsion angle and the simulated torsional angular velocity generated from the simulated machine position detection signal and the simulated motor position detection signal in the mathematical model. A simulated adaptive torsion angle compensator, a simulated main torque command and a simulated auxiliary torque command, and a pre-compensation torque adder for outputting a pre-compensation torque command. A motor position detection signal, a position controller that generates a main speed command using the motor position detection signal, a speed command adder that generates the speed command by adding the main speed command and the simulated speed command, and Based on the deviation between the speed command output from the speed command adder and the motor speed detection signal output from the speed calculator, the feedback torque From the torque command output from the torque command adder and the torque command adder that calculates the speed controller and the feedback torque command, and calculates the torque command to the electric motor by adding the pre-compensation torque command, By providing a motor control device characterized by comprising a power conversion unit for supplying appropriate electric power to the motor, even when a machine position detection signal in the equipment to be positioned cannot be detected, a vibration suppression effect can be obtained. Obtainable. Here, the simulated adaptive speed controller is expressed by the following equation.

[0009]

(Equation 8)

[0010] It may be constituted. Claims 2, 4,
5, when the deviation between any one of the machine position detection signal or the motor position detection signal in the equipment and the position command signal falls within a desired range,
A simulated adaptive speed controller according to claim 2 or claim 4.
Each of the gains of the simulated adaptive speed controller in the first embodiment or the simulated adaptive torsion angle compensator in the fifth embodiment is set as follows.

[0011]

(Equation 9)

By adopting a motor control method characterized in that switching is performed as described above, an increase in torque due to over-adjustment of the adaptive adjustment law can be prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
1 is a block diagram of the motor control device of FIG. In FIG. 1, 1 is a motor controller according to the present invention, 1a is a precompensator, 2 is a position command signal, 3 is a position controller, 4 is a main speed command which is a position controller output, and 5 is a speed controller. , 6 is a speed calculator, 7 is a speed detection signal, 8 is a torque command signal which is an output of a torque adder, 9 is a power converter, 10 is equipment including a motor and a machine, and 11 is equipment output from a mathematical model. Is a simulated position detection signal or a simulated motor position detection signal, 12 is either a facility position detection signal or a motor position detection signal output from the facility 10, 13 is a simulated position controller, and 14 is a simulated position controller. A simulated speed command, 15 is a simulated adaptive speed controller, 16 is a pre-compensation torque command, 17 is a mathematical model based on the equation of motion of equipment, 18 is a simulated speed calculator, 19 is a simulated speed detection signal, 20 Speed command adder 21 torque command adder,
29 is a feedback torque command, and 30 is a speed command. Hereinafter, description will be given based on FIG. First, the position command signal is input to the simulated position controller 3, and the simulated position controller 3 outputs an appropriate simulated speed command 14 based on a deviation from the simulated position detection signal 11 of the mathematical model. Here, the configuration of the simulated position controller may be a conventionally used PID controller. Next, based on the speed command 30 generated by adding the main speed command 4 output from the position controller 3 and the simulated speed command 14 output from the simulated position controller 13 and the position detection signal 12 of the equipment. The gain of the simulated adaptive speed controller is adaptively adjusted based on the deviation from the speed detection signal 7 which is the output of the speed calculator 6 for generating the speed, and the pre-compensation torque command is output. According to the second aspect, the output from the simulated adaptive speed controller is represented by the following equation.

[0014]

(Equation 10)

Equation (1) has a general PI control configuration, but adjusts the proportional gain and the integral gain according to the adaptive adjustment law expressed by equation (2). Equation (2) is known as a simplified adaptive adjustment rule, but because adaptive adjustment is advanced according to the deviation, the gain adjustment is appropriately performed for the vibration mode to be evaluated at the time of control execution. I do. Further, by using the adaptive speed control law not in the feedback loop but in the pre-compensator, it is possible to stably improve the responsiveness to the position command as compared with the case where the adaptive speed control rule is provided in the feedback loop. From the above, the simulated position controller uses the conventional control configuration, the position response originally determined by the control specifications can be uniquely determined by the conventional adjustment, and the adaptive control law is used for the speed controller to adaptively suppress vibration. And the control performance can be improved. Next, claim 3 will be described. FIG. 2 shows a block diagram of a motor control device according to claim 3 proposed in the present invention. In FIG. 2, 22 is a pre-compensation torque adder, 23 is a simulated main torque command, 24 is a simulated position detection signal of a machine in a mathematical model, 25 is a simulated adaptive torsion angle compensator, and 26 is a simulated motor position detection in a mathematical model. A signal 27 is a simulated assist torque command, and other symbols are the same as those in FIG. Now, description will be given based on FIG.
First, the position command signal 2 is input to the simulated position controller 13, and the simulated position controller 13 outputs an appropriate simulated speed command 14 based on a deviation from the simulated position detection signal 24 of the mathematical model. Here, the configuration of the simulated position controller may be a conventionally used PID controller. Next, based on the speed command 30 generated by adding the main speed command 4 output from the position controller 3 and the simulated speed command 14 output from the simulated position controller 13, and the position detection signal 12 of the electric motor, The gain of the simulated adaptive speed controller 15 is adaptively adjusted based on the deviation from the speed detection signal 7 which is the output of the speed calculator 6 for generating the speed, and a pre-compensation torque command is output. In claim 4, the output of the simulated adaptive speed controller 15 is represented by the following equation.

[0016]

(Equation 11)

This has the same general PI control structure as that of the second aspect, but adjusts the proportional gain and the integral gain according to the adaptive adjustment law expressed by the equation (4). (Four)
Although the equation is known as a simplified adaptive adjustment rule, the adaptive adjustment is advanced according to the deviation, so that the gain adjustment is appropriately performed for the vibration mode to be evaluated at the time of executing the control. Further, a simulated torsion angle and a simulated torsion angular velocity are generated from the simulated position detection signal 24 of the machine in the mathematical model and the simulated motor position detection signal 26 in the mathematical model, and the gain of the simulated adaptive torsion angle torque compensator is adapted using these. And outputs a simulated assist torque command to the electric motor. In claim 5, the output 27 of the simulated adaptive torsion angle compensator 25 is expressed by the following equation.

[0018]

(Equation 12)

The output 23 from the pre-compensation torque adder 22
And 27 are added to generate the pre-compensation torque command 16, so that a more damping effect can be obtained. Equation (5) is a commonly used torsion angle / torsion angular velocity feedback law, but by using it inside the precompensator 1a, an appropriate mathematical model can be obtained even when the actual machine torsion angle cannot be measured. If it is, a sufficient effect can be obtained. Also, by adjusting each gain using the adaptive law, the adaptive adjustment of the gain is advanced according to the deviation.
The gain adjustment is appropriately performed for the vibration mode to be evaluated during the control. Next, claim 6 will be described. FIG. 3 shows a flowchart of the control of the motor control device according to claim 3 proposed in the present invention. In FIG.
61 is a control start step, 62 is an adaptive control execution step in which the adaptive adjustment rule according to claim 2, 4, or 5 starts calculation in accordance with the control start, 63 is a position command and a machine position detection signal or a motor position. A step 64 of determining whether any deviation of the detection signal falls within a predetermined desired value is adjusted by the adaptive adjustment rule when the deviation falls within the desired value e * in the step 63. Each gain is

[0020]

(Equation 13)

(However, each convergence value when the deviation falls within a desired value).
In FIG. 3, when the control is started (step 61), a deviation occurs between the position command and the position detection signal, so that the adaptive adjustment rule starts the calculation and the adaptive control is executed (step 62). The deviation is reduced to 0 by the adaptive control, but it is determined whether or not the value is within a predetermined desired value (step 63), and if it is, each gain is fixed to a convergence value (step 64). ). If the deviation again deviates from the desired value, the adaptive control is executed again (step 62). This is performed to prevent over-adjustment of the adaptive adjustment rule. The adaptive adjustment rule continues to perform gain adjustment even when a small displacement occurs. result,
In many cases, the gain becomes higher or lower than necessary, resulting in over-adjustment. With the above processing, it is possible to prevent over-adjustment and automatically set the gain within a practical range.

[0022]

As described above, an appropriate gain is set in accordance with conditions even for equipment having a plurality of vibration modes, so that control performance can be improved. FIG. 6 shows a positioning control result when the conventional method is used, and FIG. 7 shows a positioning control result when the present invention is used. From FIGS. 6 and 7,
The effect of the present invention is evident since the followability of the position response to the position command is significantly improved.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention.

FIG. 2 shows a second embodiment of the present invention;

FIG. 3 shows a third embodiment of the present invention;

FIG. 4 shows a conventional example of a motor control device.

FIG. 5 is an example of a control configuration in a motor controller in FIG. 4;

FIG. 6 shows an example of a control simulation result using a conventional method.

FIG. 7 shows an example of a control simulation result using the present invention.

[Explanation of symbols]

Reference Signs List 1 motor control device 1a precompensator 2 position command signal 3 conventional position controller 4 main speed command 5 speed controller 6 speed calculator 7 machine speed detection signal or motor speed detection signal in equipment 8 torque command signal 9 power conversion Unit 10 Equipment including motor and machine 11 Simulated position detection signal or simulated motor position detection signal of equipment 12 Machine position detection signal or motor position detection signal in equipment 13 Simulated position controller 14 Simulated speed command 15 Simulated adaptive speed controller 16 Pre-compensation torque command 17 Mathematical model 18 Simulated speed calculator 19 Simulated speed detection signal 20 Speed command adder 21 Torque command adder 22 Pre-compensation torque adder 23 Simulated main torque command 24 Simulated machine position detection signal in mathematical model 25 Simulated adaptive torsion angle compensator 26 Simulated motor position in mathematical model Outgoing signal 27 Simulated auxiliary torque command 29 Feedback torque command 30 Speed command 41 Motor 42 Motor position detector 43 Work 44 Table 45 Machine stand (platen) 46 Motor controller 47 Motor drive signal 48 Motor position detection signal 49 Table position detection signal Reference Signs List 50 speed reducer 51 ball screw 52 nut supporting one end of ball screw 53 anti-vibration pad 54 position target value signal 55 motor position compensator 56 table position compensator 61 control start step 62 adaptive control execution step 63 position command and equipment position detection signal or Step 64 of judging whether any deviation of the motor position detection signal falls within a predetermined desired value 64 Each gain adjusted by the adaptive adjustment rule when the deviation falls within the desired value in 63 To

[Equation 14] Steps to set

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) BB10 DD01 FF03 FF08 GG01 GG03 GG10 JJ03 JJ22 JJ23 JJ24 KK06 LL01

Claims (6)

[Claims] 1. A motor control device for positioning an electric motor such that a motor having a plurality of vibration modes is connected to a machine having a plurality of vibration modes by a plurality of spring elements so as to perform a desired movement, wherein a position command to the equipment is input. A pre-compensator, the pre-compensator comprising a mathematical model based on the equation of motion of the equipment, a position command to the equipment and a simulated machine position detection signal or a simulated motor position detection signal in the mathematical model. A simulated position controller that generates a simulated speed command from any of the deviations, and a simulated speed calculator that generates a simulated speed detection signal of the machine from a simulated machine position detection signal or a simulated motor position detection signal in the mathematical model,
In order to determine the pre-compensation torque command to the mathematical model, using a speed command and a machine position detection signal or a motor position detection signal in the equipment, a machine speed detection signal in the equipment output from the speed calculator. Or a simulated adaptive speed controller whose gain is adaptively adjusted using a deviation from any of the motor speed detection signals, and a simulated machine position detection signal or a simulated motor position detection signal output from the mathematical model. And a position controller that generates a main speed command using either the machine position detection signal in the equipment or the motor position detection signal, and adding the main speed command and the simulated speed command to generate a speed command A speed command adder to be generated, a speed command output from the speed command adder, and a mechanical speed detection signal or electric signal in the equipment output from the speed calculator. Based on a deviation between one of the machine speed detection signal, the speed controller and the Equation 1] a torque command input to the motor from the pre-compensation torque command and the feedback torque command to generate a feedback torque command A motor control device comprising: a torque command adder determined by the formula (1); and a power converter that inputs the torque command and supplies appropriate electric power to the motor. 2. The output from the simulated adaptive speed controller is expressed by the following equation. The motor control device according to claim 1, wherein: 3. A motor control device for positioning an electric motor such that equipment having a plurality of vibration modes connected to a machine having a plurality of vibration modes by a plurality of spring elements performs desired movement, wherein a position command to the equipment is input. A simulated speed command based on a deviation between a mathematical model based on the equation of motion of the equipment, a position command to the equipment, and a simulated machine position detection signal in the mathematical model. A simulated position controller, which generates a simulated machine speed detection signal from the simulated machine position detection signal in the mathematical model, and a pre-compensated main torque command to the mathematical model, Simulated adaptive speed control that determines the gain adaptively using the deviation between the speed command and the motor speed detection signal output from the speed calculator using the motor position detection signal And a simulated torsion angle and a simulated torsional angular velocity generated from the simulated mechanical position detection signal and the simulated motor position detection signal in the mathematical model to determine a simulated auxiliary torque command to the mathematical model. A simulated adaptive torsion angle compensator that determines a gain, a simulated main torque command and a simulated auxiliary torque command are added, and a pre-compensation torque adder that outputs a pre-compensation torque command is provided. The simulated motor position detection signal output, a position controller that generates a main speed command using the motor position detection signal, and a speed that generates a speed command by adding the main speed command and the simulated speed command. A command adder, and a feed-in based on a deviation between a speed command output from the speed command adder and a motor speed detection signal output from the speed calculator. A speed controller for generating a back torque command, the feedback torque command, and the pre-compensation torque command are added together to calculate a torque command to the electric motor, and the torque output from the torque command adder. A motor control device, comprising: a power conversion unit that supplies appropriate electric power to the motor according to a command. 4. The output from the simulated adaptive speed controller according to claim 3 is expressed by the following equation. The motor control device according to claim 3, wherein: 5. The output from the simulated adaptive torsion angle compensator is represented by the following equation: The motor control device according to claim 3, wherein: 6. The motor control device according to claim 2, wherein a deviation between one of the mechanical position detection signal or the motor position detection signal in the facility and the position command signal falls within a desired range. In this case, the respective gains of the simulated adaptive speed controller according to claim 2 or the simulated adaptive speed controller according to claim 4 or the simulated adaptive torsion angle compensator according to claim 5 are expressed as follows. A motor control method characterized by switching to become