KR100252714B1 - Operating control device for virtual reality system - Google Patents

Abstract

PURPOSE: An operating control device for a virtual reality system is provided to keep a control performance constant by estimating a system parameter suitably to the number of passengers of a virtual reality system. CONSTITUTION: A reference signal for operating a virtual reality system is inputted to a reference input means(220). An inverse dynamic controller(250) generates a feed forward control force and reduces a following error in following the reference signal. A subtracting means(230) subtracts a position estimating signal of the virtual reality system from the reference signal and outputs an error signal. A PID controller(210) generates a feedback control force to stabilize an instability due to a modeling error of the inverse dynamic controller. An adding means(260) adds the feed forward control force and the feedback control force and outputs it to the virtual reality system. A system parameter estimating means(240) controls the system parameter suitably to the number of passengers. A PID controller keeping means(270) and an inverse dynamic controller keeping means(280) keeps the control performances of the PID controller and the inverse dynamic controller well by the system parameter.

Description

OPERATING CONTROL DEVICE FOR VITUAL REALITY SYSTEM

The present invention uses a feedback controller and a feedforward controller to reduce the time delay between the output and the input for reproducing the motion, and to adaptively change the system parameters so that the single-rod hydraulic cylinder has a constant control performance. It relates to a drive control device of the machine.

As shown in FIG. 1, the driving control apparatus of the conventional virtual reality motion reproducer includes a reference input unit 120 for inputting a reference signal r (t) set to arbitrarily move the cylinder of the virtual reality motion reproducer. And a subtractor 130 which outputs an error signal e (t) by subtracting the cylinder position estimation signal y (t) from the reference signal r (t) output from the reference input unit 120. A PID controller 110 for compensating through the PID (Proportion Integral Differential) control with the error signal e (t) output from the subtractor 130, and a control force output from the PID controller 110. It consists of a plant 100 operating in accordance with (u (t)) and feeding back its output y (t) to the type force of the subtractor 130.

The plant 100 drives the hydraulic unit 101 which contracts and expands the cylinder according to the sub-valve position in order to supply or return the hydraulic pressure from the hydraulic unit, and opens and closes the servo valve to drive the hydraulic pressure introduced to the cylinder or drive the hydraulic unit. The driving unit 102 to be sent to the 101, the motion is reproduced and the sensing unit 103 to operate the cylinder in accordance with the hydraulic pressure sent through the drive unit 102 and to measure the displacement in accordance with the operation of the cylinder to output the displacement measurement signal An amplifying unit 104 which amplifies the displacement measurement signal output from the motion reproducer and the sensing unit 103 and outputs a signal for operating the driving unit 102, and an output from the amplifying unit 104. The amplified position estimation signal y (t) is output to the subtractor 130 and the control force u (t) output from the PID controller 110, that is, the cylinder operation signal is output to the amplifier 104. I / O to output to It consists of 105.

The operation of the drive control device of the conventional virtual reality motion reproducer configured as described above will be described.

The reference signal r (t) is compensated through the PID control in the PID controller 110 after the output signal y (t) fed back from the plant 100 and fed back from the plant 100 in the subtractor 130 is subtracted. . That is, as shown in Equation 1 below, the output e (t) of the adder 100 is output as the control force u (t) through the PID control in the PID controller 110.

u (t) = u (t-1) + q ₀ e (t) + q ₁ e (t-1) + q ₂ e (t-2)

Where q ₀ , q ₁ , q ₂ Is the PID gain and e (t) = r (t)-y (t).

Accordingly, the error value e (t) obtained by subtracting the output value y (t) from the reference input r (t) is compensated by the PID control in the PID controller 110 to the control force u (t). Is output. The control force u (t) output from the PID controller 110 operates the plant 100 and the output value output from the plant 100, that is, the displacement y (t) with respect to the position The subtractor 130 is subtracted from the reference input r (t) which is input to the subtraction terminal (-).

Therefore, the driving control apparatus of the conventional virtual reality motion reproducer has a limitation in control performance because it controls PID depending on the output value y (t) of the plant 100 with respect to the reference input.

That is, the driving control apparatus of the conventional virtual reality motion reproducer always generates a time difference, that is, a phase difference between the reference input r (t) and the output y (t), so that the virtual reality of the virtual reality motion reproducer is generated. There was a problem of deterioration.

In addition, since the gain of the controller driving the motion reproducer is fixed, there is a problem in that it is not possible to adequately cope with a change in the exercise conditions or the number of occupants.

An object of the present invention for improving the above problems is to provide a drive control apparatus of a virtual reality motion reproducer to have a certain control performance by adaptively estimating the system parameters according to the number of occupants of the virtual reality motion reproducer have.

In addition, another object of the present invention is to provide a drive control apparatus of a virtual reality motion reproducer for enhancing the virtual reality by reducing the time delay of the output to the reference input.

In order to achieve the above object, the present invention comprises a reference input means for inputting a reference signal set to move the virtual reality motion reproducer arbitrarily, and an inverse function of a transfer function of the virtual reality motion reproducer, which is output from the reference input means. A dynamic dynamics control means for generating a feedforward control force by inputting a reference signal to reduce the tracking error when following the reference signal, and a position estimation signal of the virtual reality motion reproducer from the reference signal output from the reference input means. Subtraction means for subtracting and outputting an error signal, generating feedback control force using PID control as an input of the error signal output from the subtraction means to stabilize instability due to modeling error of the dynamic control means and improve control performance. PID control means, the dynamics agent An addition means for adding the control forces output from the means and the PID control means to output to the virtual reality motion reproducer, an assumed plant operating according to the error signal output from the subtraction means and the control power output from the adding means. A system parameter estimating means for estimating and controlling a system parameter so as to generate a position estimating signal and to output a control force adaptively according to the exercise conditions and the number of occupants of the virtual reality motion reproducer, the system parameter estimating means PID controller design means designed to maintain the control performance of the PID control means by inputting the system parameter output, and control performance of the dynamic dynamic control means by inputting the system parameter output from the system parameter estimating means. Designed to keep this dynamic It provides a drive control apparatus for a virtual reality exercise reproduction group, characterized by configured to include a crane controller design method.

1 is a configuration diagram of a drive control apparatus of a conventional virtual reality motion reproducer

2 is a configuration diagram of a drive control apparatus for a virtual reality motion reproducer according to the present invention;

<Explanation of symbols for the main parts of the drawings>

100, 200: plant 101, 201: hydraulic part

102, 202: Servo valve 103: motion reproducer and detection unit

104, 204: amplifier 105, 205: input / output unit

110, 210: PID controller 120, 220: reference input unit

130, 230: subtractor 203: motion reproducer

206 sensor 250: dynamic dynamics

260: adder

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the driving control apparatus of the virtual reality motion reproducer according to the present invention includes a reference input unit 220, a dynamics controller 250, a subtractor 230, a PID controller 210, an adder 260, System parameter estimator 240, PID controller design unit 270, and dynamics controller design unit 280.

The reference input unit 220 is for inputting a reference signal set to arbitrarily move the virtual reality motion reproducer.

The inverse dynamic controller 250 is composed of an inverse function of a transfer function of the virtual reality motion reproducer and generates a feedforward control force u2 (t) as a reference signal output from the reference input unit 220 to generate a reference signal. This will reduce the tracking error when following.

The subtractor 230 outputs an error signal e (t) by subtracting a position estimation signal of the virtual reality motion reproducer from a reference signal output from the reference input unit 220.

The PID controller 210 generates a feedback control force u1 using PID control as an input of an error signal output from the subtractor 230 to stabilize and control instability due to modeling error of the dynamics controller 250. To improve performance.

The adder 260 adds the control forces u1 and u2 output from the inverse dynamic controller 250 and the PID controller 210 and outputs them to the virtual reality motion reproducer.

The system parameter estimator 240 adaptively estimates system parameters according to the motion conditions of the virtual reality motion reproducer and the number of occupants, and outputs an error signal e (t (t)) from the subtractor 230. )) And the position estimation signal of the hypothesized plant operating according to the control force u (t) output from the adder 260 is adaptively generated according to the exercise conditions and the number of occupants of the virtual reality motion reproducer. To estimate and control the system parameters to output control power.

That is, the system parameter estimator 240 inputs an error signal e (t) output from the subtractor 230 and a control force u (t) output from the adder 260 as an input. (RecursiveLeast Square) to estimate the system parameters according to the exercise conditions and the number of occupants of the virtual reality motion reproducer to control the output adaptively.

The PID controller design unit 270 is designed to maintain the control performance of the PID controller 210 by inputting a system parameter output from the system parameter estimator 240.

The dynamics controller design unit 270 is designed to maintain the control performance of the dynamics controller 250 by inputting the system parameters output from the system parameter estimator 240.

On the other hand, the plant 200 operates according to the control force u (t) generated from the adder 260, and contracts and expands the hydraulic cylinder according to the sub-valve position in order to supply or return hydraulic pressure from the hydraulic device. The hydraulic unit 201, opening and closing the servo valve to drive the hydraulic pressure flows into the cylinder to drive or drive the hydraulic cylinder in accordance with the hydraulic pressure sent through the drive unit 202, the drive unit 202 to the hydraulic unit 201 The sensor 206 and the sensor 206 which measure displacement of the motion reproducer 203 and output a displacement measurement signal according to the operation of the motion reproducer 203 that operates, the hydraulic cylinder subjected to external disturbance ξ. An amplifying unit 204 for amplifying the displacement measurement signal outputted from the amplifier and outputting a signal for opening and closing the servo valve 202, and an amplified position estimation signal y (t) output from the amplifying unit 204 )) To the subtractor 230 And an output unit 205 for outputting a control force u (t) output from the adder 260, that is, a cylinder operation signal, which is a motion reproducer driving signal, to the amplifier 204.

The operation of the drive control device of the virtual reality motion reproducer according to the present invention configured as described above will be described.

First, the dynamics controller 250 that outputs the feedforward control force will be described.

The transfer function of the inverse dynamics controller 250 includes an inverse function of the transfer function of the virtual reality motion reproducer. That is, since the transfer function W (z ⁻¹ ) of the virtual reality motion reproducer 203 is represented by Equation 2, the transfer function W (z ⁻¹ ) ^{−1 of the} inverse dynamic controller 250. Is expressed as in Equation 3 below.

Therefore, the feed forward control force u2 (t) output from the inverse dynamic controller 250 is expressed by Equation 4 below.

That is, as shown in Equation 4 above, the feedforward control force u2 (t) output from the inverse dynamic controller 250 reproduces the motion by inputting a forward reference input r (t + 1). By dealing with the inverse of the transfer function of the group 203 in advance, the time delay, that is, the phase difference between the output y (t) and the reference input r (t) can be reduced.

The feedforward control force u2 (t) output from the dynamics controller 250 to reduce the time delay between the output y (t) and the reference input r (t) is the adder 260. Is added to the feedback control force u1 (t) output from the PID controller 210 and output to the input / output unit 205 to drive the virtual reality motion reproducer.

Using the above equation (4) to determine the inverse dynamic coefficients respectively a ₁ , a ₂ , b ₁ , b ₂ Obtain

Next, the PID controller 210 will be described in detail.

The transfer function C (z ⁻¹ ) of the PID controller is as shown in Equation 5 below.

At this time, the control force u (t) generated from the PID controller 210 is as shown in Equation 6 below.

u (t) = u (t-1) + q ₀ e (t) + q ₁ e (t-1) + q ₂ e (t-2)

On the other hand, the model equation of the plant 200 is the same as the following equation (7).

는 각각 다음 수학식 8, 9, 10 과 같다.In Equation 4 above, y (t) represents the output, u (t) represents the control force, ξ represents the disturbance,

Are the following Equations 8, 9 and 10, respectively.

Here, substituting Equation 6 into Equation 7 is as follows.

Since the distribution term on the right side of Equation 11 is the characteristic root of the closed-loop system, it represents the characteristic of the closed-loop system according to the characteristic polynomial. Let the denominator polynomial be M (z ^-1 ) and M (z ^-1 ) be quadratic. Accordingly, M (z ⁻¹ ) is expressed by Equation 12 below.

M (z ^-1 ) = 1 + M ₁ z ^-1 + M ₂ z ^-2

Since M _{1 and} M ₂ are design specifications, designers can arbitrarily adjust and determine PID coefficients using Equations 11 and 12, respectively. q ₀ , q ₁ , q ₂ Obtain

를 구하여 PID 제어기 설계부(250)로 전송하는데, 상기 시스템 매개 변수 추정부(260)에 적용된 RLS는 다음 수학식 13, 14, 15와 같다.On the other hand, the system parameter estimator 260 for determining the PID coefficients uses a recursive least square (RLS) method and

To obtain and transmit to the PID controller design unit 250, the RLS applied to the system parameter estimator 260 is the following equation (13, 14, 15).

는 추정된 시스템 매개 변수 행렬이고, L(t) 는 다음 수학식 14 에 나타낸 바와 같다.here,

Is the estimated system parameter matrix, L (t) Is as shown in Equation 14 below.

here, Φ (t) Is a state variable matrix that represents a vector for output, control input, and disturbance, λ (t) Is the forgetting factor, P (t) Is as shown in Equation 15.

By the RLS algorithm, the parameters adaptively estimated according to the number of occupants and the motion conditions of the virtual reality motion reproducer are redesigned the PID controller 210 and the dynamics controller 250. 210 and the dynamics controller 250 may adaptively output the control force u (t) according to the exercise conditions and the number of occupants of the virtual reality motion reproducer, and the output control force u (t) may be The plant 200 of the virtual reality reproducer is driven.

Therefore, the control force u (t) output from the adder 260 to control the plant, that is, the motion reproducer, is represented by Equation 16 below.

The operation of the virtual reality motion reproducer controlled using the PID controller 210 and the dynamics controller 250 will be described in detail with reference to FIG. 2.

The reference input unit 220 generates a reference signal r (t) that is set to move the virtual reality motion reproducer to an arbitrary position, inputs it to the (+) input terminal of the subtractor 230, and the subtractor 230. In the present invention, the position estimation signal y (t) of the current cylinder output from the input / output unit 205 of the plant 200 is output from the reference signal r (t) output from the reference input unit 220. It subtracts and outputs the error signal e (t).

The error signal e (t) output from the subtraction unit 230 is input to the PID controller 210 to stabilize the instability due to the modeling error of the feedforward controller and improve the control performance u1 ( t)).

That is, the PID controller 210 outputs a feedback control force u1 (t) by PID control according to Equation 1 above by inputting an error signal e (t) output from the subtractor 230. .

On the other hand, the dynamic dynamics controller 250 receives the reference signal r (t) output from the reference input unit 220 as an input of the transfer function of the virtual reality motion reproducer by the above equations (3) and (4) The feedforward control force u2 (t) is output according to the transfer function consisting of the inverse of.

The feed forward control force u2 (t) output from the inverse dynamics controller 250 is input to the adder 260 and added to the feedback control force u1 (t) output from the PID controller 210. The control force u (t) for controlling the virtual reality motion reproducer is output as shown in Equation 16 above.

The control force u (t) output from the adder 260 is input to the amplifying unit 204 through the input / output unit 205 and amplified to operate the driving unit 202. That is, the driving unit 202 is opened and closed according to the amplified cylinder operation signal output from the amplifying unit 204.

The hydraulic pressure introduced by opening and closing the servo valve is input to the hydraulic unit 201 to contract and expand the cylinder. In other words, the motion reproducer 203 moves by supplying or returning hydraulic pressure to the hydraulic device according to the position of the servovalve by opening and closing the servovalve to contract and expand the cylinder.

At this time, since the time delay, i.e., the phase difference between the output y (t) and the reference input r (t) is reduced, harmony with the image displayed on the screen is achieved without delay, so that virtual reality can be more realistically reproduced. Can be.

Meanwhile, an error signal e (t) which is subtracted from the reference signal r (t) in the subtractor 230 and fed back to the PID controller 210 and a control force u output from the adder 260 (t)) is input to the system parameter estimator 240 to estimate the plant parameters according to the number of occupants to redesign the PID controller 210 and the dynamics controller 250. That is, the system parameter estimator 240 estimates a plant parameter according to the exercise condition and the number of occupants of the virtual reality motion reproducer using the RLS according to Equations 13, 14, and 15, and the PID controller. The design unit 270 and the dynamics controller design unit 280 may redesign the PID gains of the PID controller 210 and the variables of the dynamics controller 250.

The PID controller design unit 270 redesigns the PID controller 210 using the estimated parameters output from the system parameter estimator 240 so that the PID controller 210 can be used in the number of occupants. Accordingly, the feedback control force u1 (t) can be output adaptively.

In addition, the dynamics controller design unit 280 redesigns the dynamics controller 250 by the inverse function of the transfer function of the driver using the estimated parameters output from the system parameter estimator 240. Therefore, the dynamics controller 210 can adaptively output the feedforward control force u2 (t) according to the number of occupants.

On the other hand, the sensor 206 measures the displacement of the corresponding time point of the motion reproducer 203 in accordance with the operation of the hydraulic cylinder and outputs to the amplifier 204 as a displacement measurement signal. Since the hydraulic cylinder not only operates according to the hydraulic pressure sent through the servo valve, but also receives external disturbance (ξ), the hydraulic cylinder sensor 206 in the motion reproducer 203 can change the displacement that changes according to the operation of the hydraulic cylinder. The measurement outputs the displacement measurement signal to the amplifier 204.

The displacement measurement signal output from the sensor 206 is amplified by the amplifier 204 and then the negative terminal of the subtractor 230 as a position estimation signal y (t) through the input / output unit 205. Is entered.

In addition, the PID controller 210 adaptively redesigned by the PID controller design unit 270 according to the number of occupants and the exercise conditions of the virtual reality motion reproducer, outputs a position estimation signal output from the input / output unit 205. The error signal e (t), which is the difference between y (t)) and the reference input output from the reference input unit 220, is input from the subtractor 230 to add the adaptive feedback control force u1 (t) to the adder ( 260).

In addition, in the dynamics controller 250 adaptively redesigned by the dynamics controller design unit 280 according to the number of occupants and the exercise conditions of the virtual reality motion reproducer, the reference input output from the reference input unit 220. The signal r (t) is received as an input and the adaptive feedforward control force u2 (t) is output to the adder 260.

The adaptive control force u (t) added by the adder 260 is output to the input / output unit 205 of the plant 200. At the same time, the adaptive control force u (t) is input to the system parameter estimator 260 together with the error signal e (t) to adaptively adapt the virtual reality motion reproducer and the number of occupants. System parameters can be estimated to design the PID controller 210 and the inverse dynamics controller 250.

The above-described process is continuously repeated to maintain a constant control performance regardless of the number of occupants and the motion conditions of the virtual reality motion reproducer while being resistant to modeling errors.

As described above, the driving control apparatus of the virtual reality motion reproducer according to the present invention overcomes instability due to modeling error by the feedforward controller by applying a PID controller as a feedback controller and an inverse dynamics controller as a feedforward controller. It can reduce the phase difference, which is the time delay between the input and the input, to more realistically reproduce the virtual reality due to the image, and to maintain the constant control performance regardless of the number of occupants by estimating system parameters adaptively to the number of occupants Can be.

Claims (2)

Reference input means (220) for inputting a reference signal set for arbitrarily moving the virtual reality motion reproducer; Inverse dynamics which is composed of an inverse function of the transfer function of the virtual reality motion reproducer and generates a feedforward control force (u2) from the reference signal output from the reference input means 220 to reduce the tracking error when following the reference signal. Control means 250; Subtraction means (230) for subtracting the position estimation signal of the virtual reality motion reproducer from the reference signal output from the reference input means (220) to output an error signal (e (t)); PID generating feedback control force u1 using PID control as an error signal output from the subtraction means 230 to stabilize instability due to modeling error of the dynamics control means 250 and to improve control performance. Control means 210; Addition means (260) for adding control forces (u1, u2) output from the dynamic dynamics control means (250) and the PID control means (210) and outputting them to the virtual reality motion reproducer; Generates a position estimation signal of the assumed plant operating according to the error signal e (t) output from the subtraction means 230 and the control force u (t) output from the addition means 260 System parameter estimating means (240) for estimating and controlling system parameters to adaptively output control power according to the exercise conditions and the number of occupants of the virtual reality motion reproducer; PID controller design means (270) designed to maintain the control performance of the PID control means (210) by inputting the system parameter output from the system parameter estimation means (240); And And a dynamics controller design means 270 designed to maintain the control performance of the dynamics control means 250 by inputting the system parameters output from the system parameter estimation means 240. Control device of virtual reality motion reproducer. The system of claim 1, wherein the system parameter estimating means The error signal output from the subtracting means and the control force u (t) output from the adding means 260 are input to the exercise conditions and the number of occupants of the virtual reality motion reproducer by RLS (Recursive Least Square). According to the control method of the virtual reality motion reproducer characterized in that it controls to output a control force by estimating the system parameters.

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