WO2020162202A1

WO2020162202A1 - Control device and control program

Info

Publication number: WO2020162202A1
Application number: PCT/JP2020/002263
Authority: WO
Inventors: 正樹浪江; 幸生稲目; 良昌碓井
Original assignee: オムロン株式会社
Priority date: 2019-02-08
Filing date: 2020-01-23
Publication date: 2020-08-13
Also published as: JP7031624B2; JP2020129293A

Abstract

This control device performs movement control of moving a to-be-controlled subject, which is being halted, to a specified position by outputting a manipulated variable to a drive device for driving a motor connected to the to-be-controlled subject. The control device is provided with: a generation unit that generates the manipulated variable by using a target value generated from a target track so that the to-be-controlled subject is to follow the target track; and a correction unit for multiplying the manipulated variable by a correction factor during a correction period from start of the movement control until a predetermined correction time elapses. The correction factor monotonically increases during the correction period with the passing of time. The correction factor at the end point of correction period is 1. Accordingly, it is possible to provide such a control device that can suppress torque saturation while suppressing increase in a calculation load.

Description

Control device and control program

The present technology relates to a control device and a control program.

Japanese Unexamined Patent Application Publication No. 2014-7900 (Patent Document 1) has a control unit that generates a model torque required to make the motion of a controlled object follow an operation target value, and operates the controlled object based on the model torque. A motor control device that generates a torque command is disclosed. The control unit inputs the operation target value and calculates the model torque by a filter calculation that attenuates a high frequency component equal to or higher than the cutoff frequency determined from the model gain and a predetermined frequency component. A torque command prediction value is calculated from the state variable of the filter calculation and the model torque, and a saturation prediction signal is output based on a comparison between the torque command prediction value or the absolute value of the torque command prediction value and a predetermined threshold value. The control unit calculates the model gain so as to suppress the increase in the absolute value of the model torque based on the operation target value, the saturation prediction signal, and the state variable. This reduces the torque peak and avoids torque saturation.

JP, 2014-7900, A

In the motor control device disclosed in Patent Document 1, in order to avoid torque saturation, complicated processing including calculation of model torque, calculation of a torque designated prediction value, saturation prediction, and calculation of model gain is performed. As a result, the calculation load for avoiding torque saturation is increasing.

The present invention has been made in view of the above problems, and an object thereof is to provide a control device and a control program that can reduce a torque peak while suppressing an increase in calculation load.

According to an example of the present disclosure, the control device outputs the operation amount to the drive device that drives the motor connected to the control target, and performs the movement control to move the stopped control target to the designated position. The control device generates a manipulated variable using a target value generated from the target trajectory so that the controlled object follows the target trajectory, and a movement control start time until a predetermined correction time elapses. In the correction period, a correction unit that multiplies the operation amount or the target value used to generate the operation amount by a correction coefficient is provided. The correction coefficient monotonically increases with time during the correction period. The correction coefficient at the end of the correction period is 1.

According to this disclosure, the operation amount gradually increases during the correction period from the start of the movement control, and the torque peak immediately after the start of the movement control can be reduced. By reducing the torque peak, torque saturation can be avoided. Further, since the torque peak is reduced, a small motor can be used and the cost can be reduced. Further, the calculation for multiplying the correction coefficient is simpler than the calculation for avoiding the torque saturation in Patent Document 1, and the calculation load is suppressed. In this way, the torque peak can be reduced while suppressing an increase in calculation load.

In the above disclosure, the correction coefficient increases in proportion to the elapsed time from the start of movement control. According to this disclosure, the calculation load for determining the correction coefficient can be reduced.

In the above disclosure, the correction coefficient is determined according to a function in which the elapsed time from the start of movement control is the explanatory variable and the correction coefficient is the objective variable. The differential value of the end point of the correction period in the function is 0. According to this disclosure, smooth movement of the controlled object can be realized.

In the above disclosure, the correction period is divided into two sections. The correction coefficient is determined according to a function in which the elapsed time from the start of the movement control is an explanatory variable and the correction coefficient is an objective variable. The function is a linear function in the previous section of the two sections. The function is a quintic function in which the slope of the start point of the latter section matches the slope of the linear function in the latter section of the two sections, and the second derivative of the end point of the latter section becomes 0.

According to this disclosure, it is possible to realize a smooth movement of the controlled object, and it is possible to suppress deterioration of followability to the target value immediately after the start of movement control.

In the above disclosure, movement control is control for moving a control target to a designated position in a designated time. The predetermined correction time is ½ or less of the designated time. According to this disclosure, it is possible to prevent the settling time from increasing more than the designated time.

In the above disclosure, the generation unit generates a manipulated variable using model predictive control. In the model predictive control, since the target value is immediately tracked immediately after the start of the movement control, the operation amount output to the drive device increases, and the torque value output from the drive device tends to become excessive. However, since the torque peak can be reduced as described above, by applying the model predictive control, the position of the controlled object should be settled in a well-following state at the time when the target value reaches the specified position which is the destination of movement. You can

According to an example of the present disclosure, in order to realize a control device that outputs a manipulated variable to a drive device that drives a motor connected to a control target, and performs movement control that moves a stopped control target to a designated position. The control program causes the computer to execute the following first and second steps. The first step is a step of generating a manipulated variable using a target value generated from the target trajectory so that the controlled object follows the target trajectory. The second step is a step of multiplying the operation amount or the target value used for generating the operation amount by the correction coefficient in the correction period from the start of the movement control to the passage of a predetermined correction time. The correction coefficient monotonically increases with time during the correction period. The correction coefficient at the end of the correction period is 1. Also according to this disclosure, torque saturation can be suppressed while suppressing an increase in calculation load.

According to the present invention, it is possible to suppress torque saturation while suppressing an increase in calculation load.

It is a schematic diagram which shows the structural example of the control system to which the control apparatus according to this Embodiment is applied. It is a schematic diagram which shows an example of the hardware constitutions of the control apparatus according to this Embodiment. It is a schematic diagram which shows an example of a functional structure of the control apparatus which concerns on this Embodiment. It is a figure which shows the 1st example of a correction coefficient. It is a figure which shows the 2nd example of a correction coefficient. It is a figure which shows the 3rd example of a correction coefficient. 7 is a flowchart showing a processing procedure of motor control by the control system according to the present embodiment. FIG. 7 is a diagram showing an example of an instruction code executed by the control device according to the present embodiment. It is a figure which shows the example of a simulation result when not correcting the operation amount by a correction coefficient. It is a figure which shows the example of the simulation result at the time of correct|amending the operation amount by a correction coefficient. 9 is a flowchart showing a processing procedure of motor control by the control system according to the first modification. It is a figure which shows the example of the simulation result at the time of correct|amending the target value by a correction coefficient. 9 is a schematic diagram showing an example of a functional configuration of a control device according to Modification 2. FIG.

Embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the same or corresponding parts in the drawings are denoted by the same reference characters and description thereof will not be repeated.

§1 Application Example First, an example of a scene to which the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic diagram showing a configuration example of a control system to which the control device according to the present embodiment is applied. The control system 1 of the example shown in FIG. 1 includes a controlled object 2 that is a load, one or more servo drivers, one or more servo motors, and a control device 100.

The controlled object 2 in the example shown in FIG. 1 is an XY stage that can move a working plate 3 on which a work is placed in two directions orthogonal to each other. The controlled object 2 is not limited to the XY stage, and may be any device that moves to a specified position and is positioned.

The position of the working plate 3 (hereinafter, also referred to as “load position”) may be measured by the measurement sensor 20. In the example shown in FIG. 1, the measurement sensor 20 includes two

measurement sensors

20X and 20Y. The

measurement sensors

20X and 20Y are configured by displacement sensors such as laser displacement meters. The measurement sensor 20X measures the position of the working plate 3 in the X direction. Specifically, the measurement sensor 20X measures the displacement of the end surface of the working plate 3 orthogonal to the X direction. The measurement sensor 20Y measures the position of the working plate 3 in the Y direction. Specifically, the measurement sensor 20X measures the displacement of the end surface of the working plate 3 orthogonal to the Y direction.

The one or more servo motors are motors for moving the working plate 3 of the controlled object 2, and in the example shown in FIG. 1, two

servo motors

300X and 300Y (hereinafter, also referred to as “servo motor 300”). including.

The controlled object 2 has a first base plate 4 and a second base plate 7 in addition to the working plate 3.

The first base plate 4 is provided with a ball screw 6 for arbitrarily moving the working plate 3 along the X direction. The ball screw 6 is engaged with a nut included in the working plate 3. When the servomotor 300X connected to one end of the ball screw 6 is rotationally driven, the nut included in the working plate 3 and the ball screw 6 relatively rotate, and as a result, the working plate 3 moves in the X direction. Become.

Further, the second base plate 7 is provided with a ball screw 9 for arbitrarily moving the working plate 3 and the first base plate 4 along the Y direction. The ball screw 9 is engaged with a nut included in the first base plate 4. When the servo motor 300Y connected to one end of the ball screw 9 is rotationally driven, the nut included in the first base plate 4 and the ball screw 9 are relatively rotated, and as a result, the working plate 3 and the first base plate 4 are moved in the Y direction. Will move along.

The one or more servo drivers are drive devices that drive the servo motors. In the example shown in FIG. 1, two

servo drivers

200X and 200Y (hereinafter, also referred to as “servo driver 200”)

drive servomotors

300X and 300Y, respectively.

The servo driver 200 generates a drive signal for the corresponding servo motor 300 based on the command value (command position or command speed) from the control device 100 and the feedback value from the corresponding servo motor 300. The drive signal indicates, for example, a torque command. The servo driver 200 drives the servo motor 300 by outputting the generated drive signal to the servo motor 300.

For example, the servo driver 200 receives the output signal from the encoder coupled to the rotation axis of the corresponding servo motor 300 as a feedback value. The position, rotation phase, rotation speed, cumulative rotation speed, etc. of the servo motor 300 can be detected from the feedback value.

The control device 100 outputs the operation amount to the servo driver 200 to perform movement control for moving the stopped controlled object 2 to the designated position. Data including an operation amount can be exchanged between the control device 100 and the servo driver 200.

FIG. 1 shows a configuration example in which the control device 100 and the servo driver 200 are connected via a field bus 101. However, not limited to such a configuration example, any communication means can be adopted. Alternatively, the control device 100 and the servo driver 200 may be directly connected by a signal line. Further, a configuration in which the control device 100 and the servo driver 200 are integrated may be adopted. Any implementation form may be adopted as long as an algorithm as described below is realized.

The control device 100 generates a manipulated variable to be output to the servo driver 200 by using a target value generated from the target trajectory for each control cycle so that the controlled object 2 follows the target trajectory. The control device 100 outputs the generated operation amount to the servo driver 200 as a command value (specified position or command speed). The target trajectory is created in advance for each movement control. Specifically, the target trajectory is created in advance so as to move from the initial position in the stopped state to the designated position in the designated time and stop again at the designated position.

When the movement control is started for the controlled object 2 that is stopped, the torque value output from the servo driver 200 increases immediately after the start of the movement control. In particular, when suppressing vibration in a short designated time (moving time), if the natural vibration frequency of the controlled object 2 is low, the torque value output from the servo driver 200 is likely to be excessive.

Further, even when the control device 100 executes control such as model predictive control having high tracking performance with respect to a target value, the torque value output from the servo driver 200 is likely to be excessive. This is because the control is performed so as to follow the target value early.

When torque saturation in which the torque value output from the servo driver 200 reaches the maximum torque value occurs, tracking performance with respect to the target value decreases. The maximum torque value is predetermined according to the capacity of the servo motor 300. In particular, when the control device 100 generates the manipulated variable (that is, the command value) according to the model predictive control, the prediction error of the model output increases, and the tracking performance is likely to further decrease. Although it is possible to avoid torque saturation by using a high capacity servo motor, the cost is increased.

In order to solve such a problem, the control device 100 according to the present embodiment multiplies the operation amount by the correction coefficient in the correction period from the start of the movement control to the elapse of a predetermined correction time. The correction coefficient is set so as to monotonically increase with time in the correction period, and is 1 at the end point of the correction period. As a result, the operation amount (that is, the command value) gradually increases in the correction period from the start of the movement control, and the torque peak immediately after the start of the movement control can be reduced. Further, the calculation for multiplying the correction coefficient is simpler than the calculation for avoiding the torque saturation in Patent Document 1, and the calculation load is suppressed.

§2 Specific Example Next, a specific example of the control device 100 according to the present embodiment will be described.

<A. Example of hardware configuration of control device>
Control device 100 according to the present embodiment may be implemented using a PLC (programmable controller) as an example. In the control device 100, a processor executes a control program stored in advance (including a system program and a user program, which will be described later), so that processing described later may be realized.

FIG. 2 is a schematic diagram showing an example of a hardware configuration of control device 100 according to the present embodiment. As shown in FIG. 2, the control device 100 includes a processor 102 such as a CPU (Central Processing Unit) and an MPU (Micro-Processing Unit), a chipset 104, a main memory 106, a flash memory 108, and an external network. It includes a controller 116, a memory card interface 118, an internal bus controller 122, a fieldbus controller 124, an external network controller 116, and a memory card interface 118.

The processor 102 reads the system program 110 and the user program 112 stored in the flash memory 108, expands them in the main memory 106, and executes them to realize arbitrary control of the control target. When the processor 102 executes the system program 110 and the user program 112, the operation amount output to the servo driver 200, the processing related to the data communication via the field bus, and the like, which will be described later, are executed.

The system program 110 includes instruction codes for providing basic functions of the control device 100, such as data input/output processing and execution timing control. The user program 112 is arbitrarily designed according to the control target, and includes a sequence program 112A for executing sequence control and a motion program 112B for executing motion control. By defining the function block in the user program 112, the processing and functions according to the present embodiment are realized. A function block is a component of a program executed by the control device 100, and means a modularized program element that is used multiple times.

The chipset 104 realizes the processing of the control device 100 as a whole by controlling each component.

The internal bus controller 122 is an interface for exchanging data with various devices connected to the control device 100 through an internal bus. An I/O unit 126 is connected as an example of such a device.

The fieldbus controller 124 is an interface for exchanging data with various devices connected to the control device 100 through the fieldbus. A servo driver 200 is connected as an example of such a device.

The internal bus controller 122 and the fieldbus controller 124 can give arbitrary commands to the connected device and can acquire arbitrary data (including measurement values) managed by the device. .. The internal bus controller 122 and/or the fieldbus controller 124 also function as an interface for exchanging data with the servo driver 200.

The external network controller 116 controls the exchange of data via various wired/wireless networks. The memory card interface 118 is configured such that the memory card 120 can be attached and detached, and data can be written in the memory card 120 and data can be read from the memory card 120.

<B. Servo driver>
The operation of servo driver 200 connected to control device 100 according to the present embodiment will be described. The servo driver 200 receives an operation amount from the control device 100 as a command value (command position or command speed), and receives an output signal from an encoder coupled to the servo motor 300 as a feedback value. The servo driver 200 uses the command value and the feedback value to execute the control calculation according to the control loop of the model following control system, for example.

When the servo driver 200 receives a command position as a command value, the servo driver 200 executes a control calculation according to a position control loop and a speed control loop. When the servo driver 200 receives a command speed as a command value, the servo driver 200 executes a control calculation according to a speed control loop.

The servo driver 200 executes a control calculation according to a position control loop to calculate a command speed according to a position deviation between the measured position of the servo motor 300 obtained by the feedback value and the command position given from the control device 100.

The servo driver 200 calculates the torque value according to the speed deviation between the commanded speed and the measured speed of the servo motor 300 obtained from the feedback value by executing the control calculation according to the speed control loop. The servo driver 200 outputs a current command for causing the servo motor 300 to generate a torque having the calculated torque value, to the servo motor 300.

<C. Example of functional configuration of control device>
FIG. 3 is a schematic diagram showing an example of a functional configuration of the control device according to the present embodiment. As shown in FIG. 3, the control device 100 includes a control unit 160 including a model creation module 130, a trajectory generation module 140, and a model prediction control module 150. In the figure, model predictive control is described as "MPC (Model Predictive Control)". The control device 100 includes two control units 160 corresponding to the

servo drivers

200X and 200Y, respectively. However, in FIG. 3, for simplification, only one of the two control units 160 is shown.

The model creation module 130 is typically realized by defining a model creation function block in the user program 112. That is, the model creating module 130 is functionalized by the model creating function block defined in the user program 112.

The model creation module 130 creates a dynamic characteristic model indicating the dynamic characteristics of the model target 400 including the servo driver 200, the servo motor 300, and the control target 2. The dynamic characteristic model is defined by a transfer function indicating the relationship between the operation amount and the position (load position) of the working plate 3. The model creation module 130 provides the model predictive control module 150 with parameters that define the created dynamic characteristic model.

The trajectory generation module 140 generates time-series data of the target value SP indicating the target position of the working plate 3 along the pre-created target trajectory, and obtains the target value SP corresponding to each control cycle from the time-series data. The data is sequentially read and input to the model prediction control module 150. Specifically, the trajectory generation module 140 extracts a plurality of target values SP from the current time to the end of the prediction horizon, which is a certain period in the future, from the time series data of the target values SP, and inputs them to the model prediction control module 150. To do.

Note that the control device 100 may store in advance time-series data of the target value SP that defines the target trajectory. In this case, the trajectory generation module 140 accesses the previously stored time series data of the target value SP. As described above, the target value SP for each control cycle that defines the target trajectory may be stored in advance in the form of time-series data, or the target value SP for each control cycle is sequentially calculated according to a predetermined calculation formula. You may make it calculate.

The model prediction control module 150 is typically realized by defining a model prediction control function block in the user program 112. That is, the model prediction control module 150 is functionalized by the model prediction control function block defined in the user program 112. The model prediction control module 150 includes a generation unit 151 and a correction unit 152.

The generation unit 151 generates the manipulated variable MV so that the deviation between the load position and the target position indicated by the target value is minimized by executing the model predictive control using the dynamic characteristic model. The generation unit 151 may adopt a known method as a method of model prediction control.

The correction unit 152 corrects the operation amount MV by multiplying the operation amount MV generated by the generation unit 151 by the correction coefficient in the correction period from the start of the movement control to the elapse of the predetermined correction time T. .. The correction unit 152 outputs the corrected operation amount MV to the servo driver 200 as a command value (command position or command speed).

As described above, the correction coefficient is set so as to monotonically increase over time, and is 1 at the end of the correction period. Accordingly, the operation amount gradually increases during the correction period from the start of the movement control, and the torque saturation immediately after the start of the movement control can be suppressed.

<D. Dynamic characteristic model>
The dynamic characteristic model is created by tuning in advance. When the measurement sensor 20 is installed as shown in FIG. 1, a dynamic characteristic model is created based on the input value (manipulation amount) and the output value (measurement value of the load position) obtained in tuning. .. The dynamic characteristic model is represented by, for example, the following function P(z ⁻¹ ). The function P(z ⁻¹ ) is a discrete-time transfer function that combines a dead time element and an nth-order lag element. In the dynamic characteristic model represented by the function P(z ⁻¹ ), the dead time d of the dead time element and the variables a ₁ to a _n and the variables b ₁ to b _{m of the} _nth delay element are determined as model parameters. The dead time is a time from when an input value is given to when an output corresponding to the input value appears (that is, a delay time from input to output). Optimal values may be determined for the orders n and m.

The process of creating such model parameters (that is, system identification) may be executed by the method of least squares or the like.

Specifically, the output y when the manipulated variable is given to the variable u of y=P(z ⁻¹ )*u is matched with the measured value of the load position (that is, the error is minimized). ), the value of each of the model parameters is determined.

Alternatively, the dynamic characteristic model indicates the relationship between the motor position and the load position, and the first dynamic characteristic model P _CM indicating the relationship between the operation amount and the position of the servo motor 300 (hereinafter referred to as “motor position”). It may be created by combining the second dynamic characteristic model P _ML . That is, the dynamic characteristic model is represented by P _CM *P _ML .

The first dynamic characteristic model P _CM is a model of the servo driver 200 and the servo motor 300, and is defined by a transfer function that represents a relationship between an operation amount that is an input value and a motor position that is an output value. Usually, an encoder is installed in the servo motor 300, and the motor position is continuously and highly accurately measured by the feedback value from the encoder. Therefore, the first dynamic characteristic model P _CM is created based on the measured value of the motor position.

The first dynamic characteristic model P _CM is represented by, for example, the following function P _CM (z ⁻¹ ). The function P _CM (z ⁻¹ ) is a discrete-time transfer function that combines the dead time element and the nth delay element. In the first dynamic characteristic model represented by the function P _CM (z ⁻¹ ), the dead time d of the dead time element and the variables a _CM1 to a _CMn and the variables b _CM1 to b _{CMm of the} nth delay element are determined as model parameters. To be done. Optimal values may be determined for the orders n and m.

The second dynamic characteristic model P _ML is a model of the controlled object 2, and is defined by a transfer function that represents the relationship between the motor position that is an input value and the load position that is an output value. The relationship between the motor position and the load position depends on the vibration of the controlled object 2. Therefore, the second dynamic characteristic model P _ML may be created using the waveform parameter extracted from the vibration waveform of the controlled object 2. The waveform parameter includes, for example, the vibration frequency f ₀ (typically the natural vibration frequency) of the controlled object 2 and the amplitude ratio Adr of two continuous waves in the vibration waveform. The vibration waveform of the controlled object 2 can be easily obtained from the measurement result of the measurement sensor 20.

The second dynamic characteristic model P _ML is represented by, for example, one of the functions P _ML (s) shown in [Equation 3] below. In the function P _ML (s), ω ₀ is the vibration angular frequency of the controlled object 2, and is represented by ω ₀ =2πf ₀ . ζ represents a vibration damping ratio. ζ is expressed as ζ=δ/(δ ² +4π ² ) ^1/2 using the logarithmic decay rate δ. The logarithmic attenuation rate δ is represented by δ=ln(1/Adr) using the amplitude ratio Adr of two continuous waves in the vibration waveform and the natural logarithm ln.

<E. Generation of manipulated variable MV>
The generation unit 151 generates the manipulated variable MV for each control cycle by the following model predictive control, for example.

When the dynamic characteristic model is created by the model creating module 130, the generation unit 151 performs step response calculation and ramp response calculation as preliminary preparations.

The step response calculation is a calculation for obtaining the output Ys of the dynamic characteristic model when the maximum input (step input) is continued in the initial state where the output is 0. In the following description, the output Ys at the elapsed time i (>dead time d) from the start of step input is defined as Ys(i).

The ramp response calculation is a calculation for obtaining the output Yr of the dynamic characteristic model when an input (ramp input) is increased by one step for each control cycle in the initial state where the output is 0. In the following description, the output Yr at the elapsed time i (>dead time d) from the start of the lamp input is defined as Yr(i).

The generation unit 151 performs the following processing in each control cycle during movement control.
The generation unit 151 calculates the load position in the control cycle k+d+1 (hereinafter, referred to as “predicted load position YL _k+d+1 ”) by inputting the operation amount MV generated up to the current control cycle k. The control cycle k+d+1 is a control cycle in which only the dead time d+1 defined in the dynamic characteristic model has elapsed from the end of the current control cycle k.

When the dynamic characteristic model is composed of the first dynamic characteristic model P _CM and the second dynamic characteristic model P _ML , the generation unit 151 may calculate the predicted load position YL _k+d+1 as follows. .. That is, the generation unit 151 inputs the operation amount MV generated up to the current control cycle k into the first dynamic characteristic model P _CM , so that the motor position in the control cycle k+d+1 (hereinafter, “predicted motor position YM _k+d+1 ”). Is calculated). The generation unit 151 calculates the predicted load position YL _k+d+1 in the control cycle k+d+1 by inputting the predicted motor position YM _k+d+1 into the second dynamic characteristic model P _ML .

The predicted load position YL _k+d+1 obtained as described above is used to generate the manipulated variable MV in the next control cycle. At this time, the calculated data is shifted by one control cycle in preparation for the next control cycle. For example, the predicted loading position YL k _{+ d + 1} obtained as described above is used as the estimated load position YL k _{+ d} in the next control cycle. In other words, the current control cycle k, estimated load position YL k _{+ d + 1} computed in the previous control cycle is used as the estimated load position YL k _{+ d.}

The generation unit 151 performs free response calculation in which the predicted load position YL _k+d is specified. Free response calculation is the output Yf of the dynamic characteristic model in the control cycle k+d+H after the control cycle k+d when the input after the current control cycle k is 0 in the dynamic characteristic model in the specified state in the control cycle k+d. This is a calculation for obtaining (k+d+H).

The generation unit 151 calculates the output MH _k+d+H of the dynamic characteristic model in the control cycle k+d+H after the predictive horizon from the control cycle k+d with the magnitudes of the step output and the lamp output as ks and kr, respectively, according to the following equation (1).
MH _k+d+H =ks*Ys(H)+kr*Yr(H)+Yf(k+d+H) (1)

Generating unit _151, so that the difference ΔMH the _{MH k + d + H} and the predicted load position _{YL k + d,} and a position _{RH k + d + H} on the reference trajectory in the control cycle k + d + H and difference ΔPH the estimated load position _{YL k + d} matches, ks and kr Ask for.

The reference trajectory is specified by the target value SP k+d+H in the control cycle k+d _+H and the predetermined reference trajectory time constant Tr. The position RH _k+d+H on the reference trajectory in the control cycle k+d+H is expressed by the following equation (2), for example.
RH _k+d+H =SP _k+d+H- exp(-Ts/Tr) ^H *(SP _k+d- YL _k+
_d )... Formula (2)

Two values H1 and H2 are set as H to obtain two variables ks and kr. H1 and H2 are times shorter than the vibration cycle of the controlled object 2, for example, 1/8 of the vibration cycle and 1/4 of the vibration cycle, respectively. Then, the variables ks and kr are calculated by solving the simultaneous equations including the equations of the two values H1 and H2.

The generation unit 151 may generate the product of ks obtained as described above and the step input as the manipulated variable MV _k of the current control cycle k.

<F. Correction coefficient>
Hereinafter, a specific example of the correction coefficient f(t) will be described with reference to FIGS. 4 to 6. FIG. 4 is a diagram showing a first example of the correction coefficient f(t). FIG. 5 is a diagram showing a second example of the correction coefficient f(t). FIG. 6 is a diagram showing a third example of the correction coefficient f(t).

As shown in FIG. 4, the correction coefficient f(t) of the first example increases in proportion to the elapsed time t from the start of the movement control. Specifically, the correction coefficient f(t) of the first example is a linear function f(t)=t/T having the elapsed time t as an explanatory variable.
Determined according to. T is the time length of the correction period (correction time).

The correction coefficient f(t) in the first example is determined according to a simple linear function. Therefore, the calculation load for determining the correction coefficient f(t) can be reduced. However, at the end point (t=T) of the correction period, the change in the operation amount (that is, the command value) output to the servo driver 200 may increase, and it may be difficult to smoothly move the control target 2. For example, when the command value indicates a position command, the torque value output from the servo driver 200 may suddenly decrease in the negative direction.

The correction coefficient f(t) of the second example is determined according to a function that can solve the problem of the correction coefficient f(t) of the first example and that the differential value of the end point (t=T) of the correction period is zero. To be done. In FIG. 5, a quintic function f(t)=(t/T) ³ ×{6×(t) where the two-time differential value of the starting point (t=0) and the ending point (t=T) of the correction period is 0. /T) ² −15×(t/T)+10}
The correction coefficient determined according to However, the correction coefficient f(t) of the second example may be determined not by the quintic function shown in FIG. 5, but by a cubic function in which the differential value of the end point (t=T) of the correction period is 0. ..

By using the correction coefficient f(t) of the second example, smooth movement of the controlled object 2 can be realized, but since the increase rate of the correction coefficient f(t) immediately after the start of the movement control is slow, , The ability to follow the target value is likely to be greatly reduced.

The correction coefficient f(t) of the third example can solve the problem of the correction coefficient f(t) of the second example. The upper part of FIG. 6 shows a function for determining the correction coefficient f(t) of the third example. As illustrated, the correction period of t=0 to T is divided into two sections Ta and Tb. In the previous section Ta, the correction coefficient f(t) is a linear function f(t)=t/T
Determined according to. In the subsequent section Tb, the correction coefficient f(t) has a quintic function f in which the slope of the start point of the section Tb matches the slope of the linear function in the section Tb and the second derivative of the end point of the section Tb becomes 0. (T)=(t/T) ³ ×{6×(t/T) ² −15×(t/T)+10}
Determined according to.

By using the correction coefficient f(t) of the third example, it is possible to realize a smooth movement of the controlled object 2 and to suppress deterioration of followability to the target value immediately after the start of movement control.

The lower part of FIG. 6 shows a method of creating a function for determining the correction coefficient f(t). As shown in the drawing, a quintic function g(t)=(t/T in which the twice-differentiated value of the starting point (t=0) and the ending point (t=T ₅ ) in the period of t=0 to T ₅ is 0. ₅ ) ³ ×{6×(t/T ₅ ) ² −15×(t/T ₅ )+10}
Is set. The time axis is reached from the intermediate point (t=T ₅ /2) of the curve shown by the quintic function, and the differential value at the intermediate point of the quintic function (=(15/8)×(1/T ₅ )) ) Is drawn. The line segment is represented by a linear function g(t)=(15/8)×(t/T ₅ )−7/16, and intersects the time axis at a point of t=(7/30)T ₅ .

When (7/30) T ₅ ≦t≦T ₅ /2, g(t)=(15/8)×(t/T ₅ )−7/16
And g(t)=(t/T ₅ )3×{6×(t/T ₅ )2-15×(t/T ₅ )+10} when T ₅ /2<t≦T ₅ .
The function shown in the upper part of FIG. 6 is created by converting the time width (7/30) T ₅ to T ₅ of the function g(t) represented by

<G. Processing procedure>
Next, an outline of a processing procedure of motor control by control device 100 according to the present embodiment will be described. FIG. 7 is a flowchart showing a processing procedure of motor control by the control system according to the present embodiment. The steps illustrated in FIG. 7 may be implemented by the processor 102 of the control device 100 executing a control program (including the system program 110 and the user program 112 illustrated in FIG. 2).

First, the control device 100 sets the correction time T (step S1). For example, when moving the controlled object 2 to the designated position over the designated time, the control device 100 sets a time obtained by multiplying the designated time by a predetermined ratio (for example, 1/2) as the correction time T.

Next, the control device 100 sets the elapsed time t from the start of control to 0 (step S2). After that, the control device 100 determines whether or not to start the movement control (step S3). For example, the control device 100 may check the states of the servo driver 200, the servo motor 300, the controlled object 2 and other devices, and may determine that the movement control is started by receiving a preparation completion notification from each device. .. When it is determined that the movement control is not started (NO in step S3), the motor control process is returned to step S3.

When it is determined to start the movement control (YES in step S3), the control device 100 adds the control cycle Ts to the elapsed time t from the start of control (step S4). The control device 100 executes the model predictive control using the dynamic characteristic model so that the deviation between the load position and the target position indicated by the target value SP is minimized, and the manipulated variable MV corresponding to the current control cycle. Is generated (step S5). The operation amount MV is generated in step S5 by, for example, <E. Generation of manipulated variable MV>.

Next, the control device 100 determines whether the elapsed time t from the start of control is the correction time T or less (step S6). When t≦T (YES in step S6), the control device 100 substitutes the elapsed time t from the start of control into the function for determining the correction coefficient, and thereby the correction coefficient f(t ) Is calculated (step S7). The control device 100 corrects the operation amount MV by multiplying the operation amount MV by the correction coefficient f(t), and outputs the corrected operation amount MV to the servo driver 200 (step S8).

After step S8 or when t>T (No in step S6), the control device 100 determines whether or not the movement control should be ended (step S9). The control device 100 may determine to end the movement control when the load position reaches the end point of the target trajectory and settles. When it is determined that the movement control is not ended (NO in step S9), the motor control process is returned to step S4. As a result, steps S4 to S8 are repeated. Note that steps S4 to S8 are repeated every control cycle.

If it is determined that the movement control is to be ended (YES in step S9), the motor control process is ended. The motor control of control device 100 according to the present embodiment is realized by the processing procedure as described above. The processes of steps S1 to S10 are performed for each designated servo driver 200. Therefore, the processes of steps S1 to S10 for each of the plurality of servo drivers 200 may be executed in parallel.

<H. Programming example>
The control process by control device 100 according to the present embodiment can be executed by describing an instruction in user program 112 executed by control device 100. Hereinafter, an example of programming of control device 100 according to the present embodiment will be described.

FIG. 8 is a diagram showing an example of an instruction code executed by the control device according to the present embodiment. FIG. 8 shows the model predictive control function block 115 included in the user program 112. The model prediction control function block 115 (hereinafter, referred to as “model prediction control FB115”) is a function block for defining execution of model prediction control. The model predictive control module 150 described above is realized by the model predictive control FB 115.

The model prediction control FB115 has, as input items, a start instruction 115A, a sampling period 115B, a target value 115C, a model parameter 115D, a control parameter 115E, a vibration frequency 115F, an amplitude ratio 115G, and a control start correction time. 115H. The model predictive control FB115 includes a status 115I and an operation amount 115J as output items.

In the start instruction 115A, for example, conditions for starting the model predictive control are set. In the sampling cycle 115B, the control cycle Ts for executing the calculation by the model predictive control is set.

In the target value 115C, a data array of a plurality of target values SP that defines a predetermined target trajectory of the controlled object 2 is set.

The model parameters (d, a _cm1 to a _cmn , b _cm1 to b _cmm ) for defining the first dynamic characteristic model P _CM created by the model creating module 130 are input to the model parameter _115D .

Predictive horizon values H1 and H2 used in model predictive control and a reference trajectory time constant Tr are input to the control parameter 115E.

A vibration frequency f ₀ for defining the second dynamic characteristic model P _ML is input to the vibration frequency 115F. The amplitude ratio Adr for defining the second dynamic characteristic model P _ML is input to the amplitude ratio 115G. The correction time T is input to the control start correction time 115H.

Also, from the status 115I, a value indicating the execution state of processing by the model predictive control FB 115 is output.

From the manipulated variable 115J, the manipulated variable MV is output to the servo driver as a command value. In the correction period from the start of the movement control until the correction time T elapses, the operation amount MV corrected by multiplying the operation amount MV generated by the execution of the model prediction control by the correction coefficient f(t) is output. To be done. After the correction period, the manipulated variable MV generated by executing the model predictive control is output.

<I. Simulation result>
A simulation was performed to verify the effect of the control device 100 according to the present embodiment.

FIG. 9 is a diagram showing an example of a simulation result when the operation amount MV is not corrected by the correction coefficient f(t). FIG. 10 is a diagram showing an example of a simulation result when the operation amount MV is corrected by the correction coefficient f(t). As the correction coefficient f(t), the correction coefficient f(t) of the third example shown in FIG. 6 was used.

9 and 10 show simulation results under the following conditions.
Control target: 2 inertial system,
Vibration frequency of controlled object: 9.2 Hz
Control cycle Ts: 1 ms
Dead time d: 2 ms
Predicted horizon: H1=10 control cycles, H2=18 control cycles Movement control: The control target is moved to a designated position 25 mm away at a designated time of 200 ms.

In FIG. 10, the leftmost column (a) shows the simulation result when the correction time T is 10 ms. The simulation result when the correction time T is 20 ms is shown in the second column (b) from the left. The third column from the left (c) shows the simulation result when the correction time T is 50 ms. The simulation result when the correction time T is 100 ms is shown in the fourth column (d) from the left.

In FIGS. 9 and 10, the first stage shows the time change of the target position, that is, the target trajectory and the time change of the load position. The target orbit is the 5th orbit. The second stage shows the time change of the deviation between the target position and the load position. The third stage shows the time change of the torque value output from the servo driver.

As shown in FIG. 9, when the correction coefficient f(t) is not corrected, the tracking performance for the target trajectory is maintained high, but the torque value output from the servo driver is large immediately after the start of the movement control. ..

On the other hand, as shown in FIG. 10, the operation amount MV is corrected by the correction coefficient f(t) in the correction period from the start of the movement control until the correction time T elapses. The torque value is reduced. The effect of reducing the torque value is increased by increasing the correction time T.

The longer the correction time T, the larger the deviation between the load position and the target position. However, since the correction time T is set to 1/2 or less of the designated time for moving to the designated position, the deviation between the load position and the target position becomes large only during the movement of the controlled object. Therefore, the deviation between the load position and the target position when the designated time of 200 ms has elapsed from the start of the movement control is sufficiently small. That is, the settling time from the start of the movement control until the position of the controlled object falls within the allowable range including the designated position has not increased from the designated time (200 ms).

<J. Advantage>
As described above, the control device 100 according to the present embodiment outputs the manipulated variable MV to the servo driver 200, which is a drive device that drives the servo motor 300 connected to the controlled object 2, and stops the control. A movement control for moving the object 2 to the designated position is performed. The control device 100 includes a generation unit 151 and a correction unit 152. The generation unit 151 generates the manipulated variable MV using the target value SP generated from the target trajectory so that the controlled object 2 follows the target trajectory. The correction unit 152 multiplies the operation amount MV by the correction coefficient f(t) in the correction period from the start of the movement control to the passage of the predetermined correction time T. The correction coefficient f(t) monotonically increases with the passage of time during the correction period. The correction coefficient f(T) at the end of the correction period is 1.

According to the above configuration, the operation amount MV (that is, the command value) gradually increases in the correction period from the start of the movement control, and the torque peak immediately after the start of the movement control can be reduced. By reducing the torque peak, torque saturation can be avoided. Further, since the torque peak is reduced, a small motor can be used and the cost can be reduced. Further, the calculation for multiplying the correction coefficient f(t) is simpler than the calculation for avoiding the torque saturation in Patent Document 1, and the calculation load is suppressed.

For example, the correction coefficient f(t) may increase in proportion to the elapsed time t from the start of movement control (see FIG. 4). In this case, the correction coefficient f(t) is determined according to a simple linear function. Therefore, the calculation load for determining the correction coefficient f(t) can be reduced.

Alternatively, the correction coefficient f(t) is determined according to a function having the elapsed time t from the start of the movement control as an explanatory variable and the correction coefficient f(t) as an objective variable, and the end point (t=T) of the correction period in the function. The differential value of () may be 0 (see FIG. 5). In this case, smooth movement of the controlled object 2 can be realized.

Alternatively, the correction period may be divided into two sections Ta and Tb (see FIG. 6). The function is a linear function in the previous section Ta, the slope of the starting point of the section Tb matches the slope of the linear function in the subsequent section Tb, and the second derivative value of the end point of the section Tb is 0. Is a quintic function. In this case, it is possible to realize smooth movement of the controlled object 2 and to suppress deterioration of followability to the target value immediately after the start of movement control.

-Movement control is control to move the controlled object 2 to a specified position in a specified time. The predetermined correction time T is preferably 1/2 or less of the designated time. Thereby, from the simulation result shown in FIG. 10, it is possible to prevent the settling time from increasing longer than the designated time.

<K. Modification>
<K-1. Modification 1>
In the above description, the correction unit 152 corrects the operation amount MV generated by the generation unit 151 with the correction coefficient f(t). However, the correction unit 152 may correct the target value SP by multiplying the target value SP output from the trajectory generation module by the correction coefficient f(t) instead of the operation amount MV. As described above, the generation unit 151 generates the manipulated variable MV so that the deviation between the load position and the target position indicated by the target value SP is minimized. Therefore, since the target value SP is corrected by the correction coefficient f(t), the operation amount MV (that is, the command value) gradually increases in the correction period from the start of the movement control until the correction time T elapses. , Torque saturation is suppressed.

FIG. 11 is a flowchart showing a processing procedure of motor control by the control system according to the first modification. The processing procedure shown in FIG. 11 differs from the processing procedure shown in FIG. 7 in that steps S10 and S11 are included instead of steps S5 and S8.

As shown in FIG. 11, in the control system according to the first modification, the motor control process moves to steps S6 and S7 after step S4. After step S7, the control device 100 corrects the target value SP by multiplying the target value SP by the correction coefficient f(t) (step S10).

For example, the above <E. When the manipulated variable MV is generated according to the method described in “Generation of manipulated variable MV>,” the target value SP used to generate the manipulated variable MV _k corresponding to the current control cycle k is included in the above equation (2). The target value SP _k+d+H in the control cycle k+d _+H and the target value SP _k+d in the control cycle k+d. Since the two values H1 and H2 are set as H, the control device 100 may correct the target value SP _k+d+H1 , the target value SP _k+d+H2, and the target value SP _{k+d in} the current control cycle k.

After step S10 or when t>T (NO in step S6), the control device 100 uses the dynamic characteristic model so that the deviation between the load position and the target position indicated by the target value SP is minimized. The model predictive control described above is executed to generate the manipulated variable MV (step S11). In step S11, when the target value SP is corrected by the correction coefficient f(t), the manipulated variable MV is generated using the corrected target value SP. The generated operation amount MV is output to the servo driver 200.

After that, the control device 100 determines whether or not the movement control should be ended (step S9). When it is determined that the movement control is not ended (NO in step S9), the motor control process is returned to step S4. As a result, steps S4, S6, S7, S10 and S11 are repeated. Note that steps S4, S6, S7, S10, and S11 are repeated every control cycle.

FIG. 12 is a diagram showing an example of a simulation result when the target value SP is corrected by the correction coefficient f(t). FIG. 12 shows a simulation result under the same conditions as in FIG. 10, except that the target value SP is corrected by the correction coefficient f(t) instead of the manipulated variable MV. That is, for each control cycle, the target value SP of the control cycle after the dead time d (=2 ms) has elapsed, the target value SP of the control cycle after the dead time d (=2 ms)+H1 (=10 ms), and the dead time. The target value SP of the control cycle after d (=2 ms)+H2 (=18 ms) has been corrected by the correction coefficient f(t).

In FIG. 12, the leftmost column (a) shows the simulation result when the correction time T is 10 ms. The simulation result when the correction time T is 20 ms is shown in the second column (b) from the left. The third column from the left (c) shows the simulation result when the correction time T is 50 ms. The simulation result when the correction time T is 100 ms is shown in the fourth column (d) from the left.

As shown in FIG. 12, by correcting the target value SP with the correction coefficient f(t) during the correction period from the start of the movement control until the correction time T elapses, the torque value output from the servo driver is reduced. To be done. The effect of reducing the torque value is increased by increasing the correction time T. Furthermore, it was confirmed that the settling time did not increase from the specified time (200 ms) when the correction time T was set to 1/2 or less of the moving time to the specified position.

<K-2. Modification 2>
FIG. 13 is a schematic diagram illustrating an example of the functional configuration of the control device according to the second modification. As shown in FIG. 13, a control device 100A according to Modification 2 is different from the control device 100 shown in FIG. 3 in that a control unit 160A is provided instead of the control unit 160. The control unit 160A differs from the control unit 160 in that it includes a model predictive control module 150A instead of the model predictive control module 150. The model prediction control module 150A differs from the model prediction control module 150 in that it includes a generation unit 151A instead of the generation unit 151.

The measured value PV of the position (load position) of the controlled object 2 is fed back to the model predictive control module 150A of the control device 100A according to Modification 2. The measurement value PV is measured by the measurement sensor 20 shown in FIG. 1 and transmitted from the measurement sensor 20 to the control device 100A.

The generation unit 151A differs from the generation unit 151 in that the measured load value PV is used to correct the predicted load position YL.

For example, the generation unit 151A calculates the difference value between the predicted load position YL _k and the measured value PV _k in the current control cycle k as the correction amount CL. That is, the correction amount CL is
CL=PV _k- YL _k
It is represented by.

Next, the generation unit 151A updates the predicted load position YL _k to the measured value PV _k, and also updates the predicted load position YL in the future for the dead time d according to the following equation using the correction amount CL.
YL _k+1 ← YL _k+1 +CL
...
YL _k+d ← YL _k+d +CL
As a result, the accuracy of the predicted load position YL can be improved. As a result, it is possible to improve the followability to the target trajectory in the movement control.

When the dynamic characteristic model is composed of the first dynamic characteristic model P _CM and the second dynamic characteristic model P _ML , the generating unit 151A replaces the predicted load position YL with the predicted load position YL or corrects the predicted load position YL. In addition to the correction, the predicted motor position YM may be corrected using the measured value PVM of the motor position received from the servo motor 300.

For example, the generation unit 151A calculates a difference value between the predicted motor position YM _k and the measured value PVM _k in the current control cycle k as the correction amount CM. That is, the correction amount CM is
CM=PVM _k- YM _k
It is represented by.

Next, the generation unit 151A updates the predicted motor position YM _k to the measured value PVM _k, and updates the future predicted motor position YM for the dead time d according to the following equation using the correction amount CM.
YM _k+1 ← YM _k+1 +CM
...
YM _k+d ← YM _k+d +CM
This increases the accuracy of the predicted motor position YM and the accuracy of the predicted load position YL. As a result, it is possible to improve the followability to the target trajectory in the movement control.

<K-3. Modification 3>
In the above description, the

generation units

151 and 151A perform model predictive control using the dynamic characteristic model indicating the dynamic characteristics of the model target 400 including the servo driver 200, the servo motor 300, and the control target 2, and generate the manipulated variable MV. I decided to do it. However, when the vibration suppression of the controlled object 2 is unnecessary, the

generation units

151 and 151A perform model predictive control using the dynamic characteristic model indicating the dynamic characteristics of the model target 400 including the servo driver 200 and the servo motor 300. The operation amount MV may be generated. In this case, in the model predictive control FB 115 (see FIG. 8) that realizes the model

predictive control modules

150 and 150A, the input items of the vibration frequency 115F and the amplitude ratio 115G are omitted.

<L. Note>
As described above, the present embodiment and modifications include the following disclosures.

(Structure 1)
The operation amount is output to the drive device (200, 200X, 200Y) that drives the motor (300, 300X, 300Y) connected to the controlled object (2), and the stopped controlled object (2) is designated. A control device (100, 100A) for performing movement control for moving to
A generation unit (102, 151, 151A) that generates the manipulated variable by using a target value generated from the target trajectory so that the controlled object (2) follows the target trajectory.
A correction unit (102, 152) for multiplying the operation amount or the target value used for generating the operation amount by a correction coefficient during a correction period from the start of the movement control until a predetermined correction time elapses. Prepare,
The correction coefficient monotonically increases with time in the correction period,
The control device (100, 100A), wherein the correction coefficient at the end of the correction period is 1.

(Configuration 2)
The control device (100, 100A) according to configuration 1, wherein the correction coefficient increases in proportion to an elapsed time from the start of the movement control.

(Structure 3)
The correction coefficient is determined according to a function having an elapsed time from the start of the movement control as an explanatory variable and the correction coefficient as an objective variable,
The control device (100, 100A) according to configuration 1, wherein the differential value of the end point of the correction period in the function is 0.

(Structure 4)
The correction period is divided into two sections,
The correction coefficient is determined according to a function having an elapsed time from the start of the movement control as an explanatory variable and the correction coefficient as an objective variable,
The function is a linear function in the previous section of the two sections,
In the function, in the latter section of the two sections, the slope of the starting point of the latter section matches the slope of the linear function, and the second derivative of the end point of the latter section becomes 0. 5 The control device (100, 100A) according to configuration 1, which is a next function.

(Structure 5)
The movement control is control for moving the controlled object (2) to the designated position in a designated time,
The control device (100, 100A) according to any one of configurations 1 to 4, wherein the predetermined correction time is half or less of the specified time.

(Structure 6)
The control unit (100, 100A) according to any one of configurations 1 to 5, wherein the generation unit (102, 151, 151A) generates the manipulated variable by using model predictive control.

(Structure 7)
The operation amount is output to the drive device (200, 200X, 200Y) that drives the motor (300, 300X, 300Y) connected to the controlled object (2), and the stopped controlled object (2) is designated. A control program (110, 112) for realizing a control device (100, 100A) for performing movement control for moving to
The control program causes the computer to
Generating a manipulated variable using a target value generated from the target trajectory so that the controlled object (2) follows the target trajectory;
In a correction period from the start of the movement control until a predetermined correction time elapses, a step of multiplying the operation amount or the target value used to generate the operation amount by a correction coefficient is executed,
The correction coefficient monotonically increases with time in the correction period,
The control program, wherein the correction coefficient is 1 at the end of the correction period.

Although the embodiments of the present invention have been described, the embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1 control system, 2 control target, 3 working plate, 4 first base plate, 6,9 ball screw, 7 second base plate, 20, 20X, 20Y measurement sensor, 100, 100A control device, 101 fieldbus, 102 processor, 104 chip Set, 106 main memory, 108 flash memory, 110 system program, 112 user program, 112A sequence program, 112B motion program, 115 model predictive control function block, 115A start instruction, 115B sampling period, 115C target value, 115D model parameter, 115E Control parameters, 115F vibration frequency, 115G amplitude ratio, 115H control start correction time, 115I status, 115J operation amount, 116 external network controller, 118 memory card interface, 120 memory card, 122 internal bus controller, 124 fieldbus controller, 126 I/O unit, 130 model creation module, 140 trajectory generation module, 150, 150A model predictive control module, 151, 151A generation unit, 152 correction unit, 160, 160A control unit, 200, 200X, 200Y servo driver, 300, 300X , 300Y servo motor, 400 model target.

Claims

A control device that outputs a manipulated variable to a drive device that drives a motor connected to a controlled object, and that performs movement control to move the stopped controlled object to a designated position,
A generation unit that generates the manipulated variable using a target value generated from the target trajectory so that the controlled object follows the target trajectory.
In a correction period from the start of the movement control until a predetermined correction time elapses, a correction unit for multiplying the operation amount or the target value used to generate the operation amount by a correction coefficient,
The correction coefficient monotonically increases with time in the correction period,
The control device, wherein the correction coefficient at the end of the correction period is 1.
The control device according to claim 1, wherein the correction coefficient increases in proportion to the elapsed time from the start of the movement control.
The correction coefficient is determined according to a function having an elapsed time from the start of the movement control as an explanatory variable and the correction coefficient as an objective variable,
The control device according to claim 1, wherein a differential value of an end point of the correction period in the function is 0.
The correction period is divided into two sections,
The correction coefficient is determined according to a function having an elapsed time from the start of the movement control as an explanatory variable and the correction coefficient as an objective variable,
The function is a linear function in the previous section of the two sections,
In the function, in the latter section of the two sections, the slope of the starting point of the latter section matches the slope of the linear function, and the second derivative of the end point of the latter section becomes 0. 5 The control device according to claim 1, which is a quadratic function.
The movement control is control for moving the control target to the designated position in a designated time,
The control device according to any one of claims 1 to 4, wherein the predetermined correction time is half or less of the designated time.
The control device according to any one of claims 1 to 5, wherein the generation unit generates the manipulated variable by using model predictive control.
A control program for realizing a control device that outputs a manipulated variable to a drive device that drives a motor connected to a controlled object, and that performs a movement control for moving the stopped controlled object to a designated position,
The control program causes the computer to
A step of generating the manipulated variable using a target value generated from the target trajectory so that the controlled object follows the target trajectory;
In a correction period from the start of the movement control until a predetermined correction time elapses, a step of multiplying the operation amount or the target value used to generate the operation amount by a correction coefficient is executed,
The correction coefficient monotonically increases with time in the correction period,
The control program, wherein the correction coefficient is 1 at the end of the correction period.