KR20050109677A - An overshoot reduction system and method for the precision robot actuated with piezoeletric device - Google Patents

Abstract

The present invention relates to an overshoot reduction driving system and a method thereof for a robot actuator. The present invention relates to a robot actuator by driving an algorithm for calculating an overshoot reduction coefficient preset according to a damping coefficient and a resonance frequency detected through a test drive of a predetermined robot actuator. By calculating the optimum first and second overshoot reduction coefficients suitable for, and generating three step input voltages according to the calculated first and second overshoot reduction coefficients, the actuator is driven by driving the robot actuator. It reduces overshoot during driving and prevents the end effect of the actuator and damage to the object.

Description

An overshoot reduction system and method for the precision robot actuated with piezoeletric device}

The present invention relates to a drive system for reducing overshoot of a robot actuator and a method for reducing the overshoot generated when the robot actuator is driven to prevent end effect of the robot actuator or damage to an object. will be.

Recently, new industries such as information technology (IT), biotechnology (BT), or nanotechnology (NT) are moving toward the trend of miniaturization and super precision, and as the new industrial market is formed, ultra precision that can produce and process these products The use of production systems is becoming a key factor in securing competitiveness. Especially in the BT field, which is attracting attention along with the genome project, the size of DNA is 3nm ~ 4nm, ribosomal is less than 100nm, and the largest general cells are as fine as 10㎛. Ultra precision instruments are needed to handle and manipulate them, and the NT industry is also increasing the need for ultra precision instruments to handle and measure nanoscale structures.

Therefore, a micro robot is required for the assembly of micro parts required for ultra-precision devices related to NT, BT, IT, etc. As a core part thereof, there is a micro robot actuator designed to move by a predetermined microdisplacement in three degrees of freedom, such as a manipulator. .

Miniature robot actuators, such as the manipulators described above, are devices that can precisely control the position of micro grippers and the like that pick up very fine objects in micrometer size, and are used as core parts for handling micro parts.

On the other hand, Figure 1 is a view showing a conventional overshoot reduction system and method, as shown in the general overshoot reduction system and method, the robot actuator is attached to the encoder by the position sensor to drive the robot actuator. According to the encoder detects the results vary depending on the driving and feedback to the PID (Proportional Integral Derivative Control) control, but set to over-attenuate the PID gain, AMP signal corresponding to the result controlled by the PID controller By amplifying the required level when driving the actuator to reduce the overshoot generated during driving.

However, such a conventional overshoot reduction system and its method are difficult to apply to recent ultra-precision robot actuators that operate in an open loop using piezoelectric elements, and thus, a new and improved overshoot reduction is further improved. You need a system or method.

Accordingly, the present invention was developed to satisfy the above-mentioned necessity, to minimize the overshoot generated when driving a high-precision robot actuator operating in an open loop using a piezoelectric element, the robot actuator of the An object of the present invention is to provide a drive system and method for reducing overshoot.

In accordance with this purpose, the present invention is to operate the overshoot reduction coefficient calculation algorithm preset according to the damping coefficient and the resonance frequency detected by the test drive of a predetermined robot actuator, and thus the first and second optimum The overshoot reduction coefficient is calculated and three step input voltages are generated according to the calculated first and second overshoot reduction coefficients, and the robot actuator is then driven to reduce the overshoot generated when the actuator is driven. .

To this end, the present invention detects the damping coefficient and the resonant frequency of the robot actuator from the response results measured by the test drive of the robot actuator, and predetermined predetermined overshoot reduction coefficient calculation algorithm according to the detected damping coefficient and the resonant frequency An overshoot reduction coefficient calculating means for driving the to calculate an optimum first and second overshoot reduction coefficients suitable for the robot actuator;

Overshoot is generated by generating three step input voltages according to the first and second overshoot reduction coefficients calculated by the overshoot reduction coefficient calculating means at a predetermined displacement input voltage applied to move the robot actuator by a predetermined displacement. Overshoot reduction control means for controlling to reduce the amount of noise;

A drive system for reducing overshoot of a robot actuator, comprising: an actuator drive voltage adjusting unit configured to adjust the three step input voltages generated by the overshoot reduction control means to a driving voltage level of the robot actuator and output the same to the robot actuator. Initiate.

In still another aspect of the present invention, a first process of detecting the damping coefficient and the resonant frequency of the robot actuator from the response result measured by the test drive of the robot actuator;

A second step of calculating an optimal first and second overshoot reduction factor suitable for the robot actuator by driving a predetermined overshoot reduction factor calculation algorithm according to the damping coefficient and the resonance frequency detected in the first step; ;

A third step of generating a predetermined displacement input voltage applied to move the robot actuator by a predetermined displacement as three step input voltages according to the first and second overshoot reduction coefficients calculated in the second process;

A fourth step of adjusting the step input voltage of the three stages converted in the third step to the driving voltage level of the corresponding robot actuator;

A fifth step of driving the robot actuator with the step input voltage of three stages adjusted to the driving voltage level of the robot actuator in the fourth process, the method for reducing the overshoot of the robot actuator is disclosed.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

First, the overshoot reduction driving system of the robot actuator according to the present invention will be described with reference to FIG. 2.

As shown in FIG. 2, the robot actuator overshoot reduction driving system of the present invention detects the damping coefficient and the resonance frequency of the robot actuator from the response result measured through the test drive of the robot actuator, and detects the damping. An overshoot reduction coefficient calculating means 200 for driving a predetermined overshoot reduction coefficient calculation algorithm preset according to the coefficient and the resonance frequency to calculate an optimum first and second overshoot reduction coefficient suitable for the robot actuator; Three-stage step input variable according to the first and second overshoot reduction coefficients calculated by the overshoot reduction coefficient calculating means 200 for a predetermined displacement input voltage applied to move the robot actuator by a predetermined displacement. Overshoot reduction control means (300) for generating a voltage to reduce the overshoot with the generated three-step input voltage, and the overshoot It comprises an actuator drive voltage control unit 400 for adjusting the step input voltage of the three stages generated by the abatement control means 300 to the driving voltage level of the robot actuator, and outputs it to the robot actuator.

In the driving system of the present invention, the overshoot reduction coefficient calculating means 200 first detects the damping coefficient and the resonance frequency of the corresponding robot actuator from the response result measured through the test drive of the robot actuator, and detects the damping coefficient and A predetermined overshoot reduction factor calculation algorithm is set in accordance with the resonance frequency to calculate optimal first and second overshoot reduction factors suitable for the robot actuator.

That is, the overshoot reduction coefficient calculating means 200 applies a displacement input voltage applied to move the robot actuator by a predetermined displacement, for example, to about half of the maximum driving voltage, and applies the displacement input voltage to the robot actuator, and then measures the response result. Then, the damping coefficient and the resonant frequency of the robot actuator are detected from the approximated secondary system.

Estimated Secondary System = h / (s ² + fs + g)

w = , ξ = f / 2 }, (w is the resonant frequency, ξ is the damping coefficient)

Then, a predetermined overshoot reduction coefficient calculation algorithm is set to apply the following equation 2 according to the detected damping coefficient and the resonance frequency to reduce the optimal first and second overshoot suitable for the robot actuator. Calculate the coefficient.

A ₁ = 1 / (1 + 2M + M ² ), T ₁ = 0

A ₂ = 2M / (1 + 2M + M ² ), T ₂ = Of

A ₃ = M ² / (1 + 2M + M ² ), T ₃ = 2T ₂

And M = e ^{-ξπ /} to be.

In this way, when the optimum first and second overshoot reduction coefficients suitable for the robot actuator are calculated, the overshoot reduction control means 300 of the present invention is a displacement applied to move the robot actuator by a predetermined displacement as in the prior art. Instead of the input voltage, three step input voltages which are variable according to the first and second overshoot reduction coefficients calculated by the overshoot reduction coefficient calculating means 200 are generated to generate the three step input voltages. To drive the robot actuator.

That is, the overshoot reduction control means 300 of the present invention replaces the displacement input voltage having a predetermined single magnitude with a predetermined three-step step input voltage having different magnitudes for a corresponding time, as in the prior art. According to the second overshoot reduction coefficient, the robot actuator is generated separately according to the second overshoot reduction factor, thereby minimizing the overshoot that may occur during driving. More specific aspects will be described later. .

On the other hand, when a predetermined three-step step input voltage according to the present invention is generated by the overshoot reduction control means 300, the actuator driving voltage adjusting unit 400 generates three stages generated by the overshoot reduction control means 300. By amplifying the step input voltage of the predetermined predetermined amplification degree to adjust the driving voltage level of the robot actuator to output to the corresponding robot actuator, thereby enabling the robot actuator to be driven without overshoot or with only a minimum overshoot. .

As described above, the driving system according to the present invention drives the preset overshoot reduction coefficient calculation algorithm according to the damping coefficient and the resonance frequency detected through the test drive of the predetermined robot actuator, so as to be optimized for the robot actuator. Calculates the second overshoot reduction coefficient and variably generates three step input voltages according to the calculated first and second overshoot reduction coefficients, thereby driving the robot actuator. Overshoot is reduced to a minimum. Hereinafter, preferred embodiments of the overshoot reduction control means used in the present invention will be described.

A preferred aspect of the overshoot reduction control means 300 used in the present invention is a predetermined start according to the first overshoot reduction coefficient calculated by the overshoot reduction coefficient calculating means 200, as shown in FIG. First, second, and three hour delay units 321, 322, and 323 respectively outputting unit pulses delayed by different times based on time, and a second over calculated by the overshoot reduction coefficient calculating means 200. First, second, and third step input voltage output units 311, 312, and 313 respectively outputting step input voltages having different magnitudes according to the shooting reduction coefficient, and a predetermined enable signal according to an actuator driving command from the outside. An actuator drive command unit 330 for outputting a unit, a unit pulse output from each of the first time delay unit 321, a step input voltage output from the first step input voltage output unit 311, and the actuator Output from the drive command unit 330 A first multiplier 340 multiplying the enable signal, a unit pulse output from each of the second time delay units 322, a step input voltage output from the second step input voltage output unit 312, A second multiplier 350 multiplying the enable signal output from the actuator driving command unit 330, a unit pulse output from each of the third time delay unit 323, and the third step input voltage output unit. A third multiplier 360 multiplying the step input voltage output at 323, the enable signal output from the actuator driving command unit 330, and the first, second and third multipliers 340, 350, and 360; The adder 370 outputs to the actuator driving voltage adjusting unit 400 by adding the multiplied result.

In the preferred overshoot reduction control means of the present invention, the first, second, and third time delay units 321, 322, and 323 firstly calculate the first overshoot reduction calculated by the overshoot reduction coefficient calculating means 200. According to the coefficients, the unit pulses are delayed by different times with respect to a predetermined start time and outputted respectively.

In addition, each of the first, second, and third step input voltage output units 311, 312, and 313 is mutually dependent on the second overshoot reduction coefficient calculated by the overshoot reduction coefficient calculating means 200. Step input voltages having different magnitudes are output to the actuator, and the actuator driving command unit 330 also outputs a predetermined enable signal according to an actuator driving command from the outside.

Then, the first multiplier 340 outputs the unit pulse delayed by the first time delay unit 321 by a predetermined time, the step input voltage output from the first step input voltage output unit 311, and the actuator driving. Each of the enable signals output from the command unit 330 is input and multiplied, and the second multiplier 350 is longer than the delay time of the first time delay unit 321 by the second time delay unit 322. A third multiplier that receives and multiplies the unit pulse output by the delay, the step input voltage output from the second step input voltage output unit 312 and the enable signal output from the actuator driving command unit 330, respectively, The unit 360 outputs a unit pulse delayed by the third time delay unit 323 by a predetermined time longer than the delay time of the second time delay unit 322 and output by the third step input voltage output unit 323. One step input voltage and the actuator drive command unit 330 Multiplies each received input to the enable signal entered.

Lastly, when a predetermined multiplication result is calculated through the multipliers 340, 350, and 360 described above, and a signal corresponding thereto is output, the adder 360 generates the first, second, and third multipliers 340, 350. , 360) By generating the multiplied by each of the multiplied by the result value to generate the step input voltage of the three stages used in the present invention, the three step input voltage generated in this way is the actuator drive voltage control unit 400 It is outputted to and amplified by a predetermined degree of amplification to drive the robot actuator with minimal overshoot.

Next, a second preferred embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 3, the second embodiment of the present invention provides a time manager for managing delay times of the first, second, and three time delay units 321, 322, and 321. As an aspect further including 324, the time manager 324 is provided with the first, second, and third time delay units 321, in accordance with the first overshoot reduction coefficient calculated by the overshoot reduction coefficient calculating means 200. Delay time of the unit pulses output from each of the 322 and 321 is determined based on a predetermined start time, and then the first, second and third time delay units 321, 322 and 321 are determined. Delayed by the corresponding delay time determined in each control so that the corresponding unit pulses can be sequentially output. As a result, each of the first, second, and third time delay unit (321, 322, 321) Based on a predetermined start time, each of the outputs can be delayed by a different time. By using the enable signal of the actuator driving command unit and the step input voltage of different magnitudes output from the step input voltage output units, three step input voltages used in the present invention can be generated. Reference is made to practical systems to which the present invention is applied.

As shown in FIG. 4, the present invention is connected to the three degree of freedom microdisplacement drive device 500 through a predetermined cable. First, the three stages generated by the overshoot reduction control means 300 according to the present invention. When the step input voltage is amplified by a predetermined degree of amplification in the actuator driving voltage adjusting unit 400 and transmitted to a robot actuator, for example, a piezoelectric element as shown in the drawing through a predetermined cable, it is connected to a gripper or the like and moves it by a predetermined displacement The first micro-movement unit is to move the push rod provided at the end in the forward / backward direction in accordance with the transmitted voltage to perform a linear drive.

At this time, the present invention, unlike the conventional use of a single-size displacement input voltage, by using a predetermined three-step step input voltage generated in accordance with the present invention to minimize the overshoot that can occur during the linear drive to a minimum As a result, the overshoot is minimized when the tilt driving is performed according to the interlock between the second smile moving part and the tilt driving part, and the fan driving according to the interlocking between the third smile moving part and the tilt driving part and the fan driving part is minimized. The drive is performed.

Next, the present invention will be described in more detail with reference to the timing diagram of FIG. 5.

As shown in FIG. 5, the three step input voltages used in the present invention are generated as a sum of predetermined first, second and third step input voltages as shown in FIG. The A1 size pulse generated according to the second overshoot reduction coefficient is multiplied by the unit pulse delayed for the time T1 based on the predetermined start time, and the second step input voltage is generated according to the second overshoot reduction coefficient. The unit pulse delayed for T2 time is multiplied based on the A2 size pulse and the start time, and the third step input voltage is T3 based on the A3 size pulse and the start time generated according to the second overshoot reduction factor. The unit pulse delayed for a time is multiplied, and the result of summing the first, second, and third step input voltages formed by this multiplication is the three step input voltage used in the present invention. Voltage changes It can even reduce the overshoot increase substantially if the command execution time for it is possible to prevent the end effector (end effect) or the destruction of the target due to the overshooting.

Next, the overshoot reduction driving method according to the present invention will be described with reference to FIG. 6.

As shown in FIG. 6, in the overshoot reduction driving method according to the present invention, first, when an overshoot reduction coefficient measurement command is input from an external device to a predetermined measurement device (S600), the predetermined measurement device. Is a preset standard driving voltage for measurement, for example, a voltage corresponding to about half of the maximum driving voltage of the robot actuator is output to the robot actuator (S601), and measured through a test drive of the robot actuator performed through the measurement (S602, S603). After detecting the damping coefficient and the resonant frequency of the corresponding robot actuator (S604), the predetermined overshoot reduction coefficient calculation algorithm is driven by the predetermined damping coefficient and the resonant frequency detected in step S604. The optimal first and second overshoot reduction coefficients suitable for the robot actuator are calculated (S605).

Thereafter, three step input voltages are generated according to the first and second overshoot reduction coefficients calculated in step S605 for the displacement input voltage applied to move the robot actuator by a predetermined displacement. The three-stage step input voltage generation mode according to the first and second overshoot reduction coefficients will be described in more detail.

The three-step step input voltage generation used in the present invention is mutually based on a predetermined start time according to the first overshoot reduction coefficient calculated in step S605, that is, the different delay times T1, T2, and T3. Output the first, second, and third unit pulses delayed by different times (T1, T2, T3) (S606, S609, S612) and simultaneously or separately with each of the steps (S606, S609, S612). According to the second overshoot reduction coefficients A1, A2, and A3 calculated in S605, the first, second, and third step input voltages having different magnitudes are respectively output (S607, S610, and S613), and step ( If a predetermined enable signal is output simultaneously with each of S606, S609, S612 and steps S607, S610, and S613, or in response to an actuator driving command from the outside, the respective enable signals are output in steps S606, S609, and S612. By interlocking the first, second, third unit pulses with the first, second, third step input voltages and the enable signals output in steps S606, S609, and S612, A predetermined three-step step input voltage is generated (S615).

For example, in step S608, the unit pulse output by delaying by T1 time is multiplied by the step input voltage of A1 size, and in step S611, the unit pulse output by delaying by T2 time and output by A2 size step input voltage. Multiplying the output unit pulse by delaying by T2 hours according to the step (S614) and the step input voltage of the A3 size, and then multiplying the multiplied resultant value by A step input voltage is generated (S615).

On the other hand, if a predetermined three-stage step input voltage is generated according to the present invention in step S616, and adjusts the three-step step input voltage generated in this way to the driving voltage level of the robot actuator (s617), step (S617) By driving the robot actuator with three step input voltage adjusted to the driving voltage level of the robot actuator, the overshoot generated when the actuator is driven is minimized.

As described above in detail, an overshoot reduction driving system and method thereof for robot actuators according to the present invention include an algorithm for calculating an overshoot reduction coefficient preset according to a damping coefficient and a resonance frequency detected through a test drive of a predetermined robot actuator. To calculate the optimum first and second overshoot reduction coefficients suitable for the robot actuator, and generate three step input voltages according to the calculated first and second overshoot reduction coefficients. By driving the robot actuator, it is possible to reduce the overshoot generated when the actuator is driven, thereby preventing the end effect of the actuator and the damage of the target.

Although the invention has been described in detail only with respect to the specific examples described, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

1 is a view showing a drive system for reducing a general overshoot,

2 is a view showing a first embodiment of a drive system for reducing overshoot of the present invention;

3 is a view showing a second embodiment of a drive system for reducing overshoot of the present invention;

4 is a view showing a state diagram of use of the present invention,

5 is a timing diagram for explaining the present invention in more detail;

6 is a view showing a drive method for reducing overshoot according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

200: overshoot reduction coefficient calculation means

300: overshoot reduction control means

321: first time delay unit 322: second time delay unit

323: third time delay unit 311: first step input voltage output unit

312: second step input voltage output unit 313: third step input voltage output unit

330: actuator drive instruction unit 340: first multiplier

350: second multiplier 360: third multiplier

370: adder 400: actuator drive voltage control unit

Claims (8)

The damping coefficient and the resonant frequency of the robot actuator are detected from the response results measured through the test drive of the robot actuator, and the predetermined overshoot reduction coefficient calculation algorithm is driven according to the detected damping coefficient and the resonant frequency to operate the robot actuator. Overshoot reduction coefficient calculating means for calculating an optimal first and second overshoot reduction coefficients suitable for the < RTI ID = 0.0 > Overshoot is generated by generating three step input voltages according to the first and second overshoot reduction coefficients calculated by the overshoot reduction coefficient calculating means at a predetermined displacement input voltage applied to move the robot actuator by a predetermined displacement. Overshoot reduction control means for controlling to reduce the amount of noise; A drive system for reducing overshoot of a robot actuator, comprising: an actuator drive voltage adjusting unit configured to adjust the three step input voltages generated by the overshoot reduction control means to a driving voltage level of the robot actuator and output the same to the robot actuator. . The method of claim 1, wherein the overshoot reduction control means; First, second, and third time delay units respectively outputting unit pulses delayed by different times based on a predetermined start time based on the first overshoot reduction coefficient calculated by the overshoot reduction coefficient calculating means; First, second, and third step input voltage output units respectively outputting step input voltages having different magnitudes according to second overshoot reduction coefficients calculated by the overshoot reduction coefficient calculating means; An actuator driving command unit for outputting a predetermined enable signal according to an actuator driving command from the outside; A first multiplier multiplying a unit pulse output from each of the first time delay units, a step input voltage output from the first step input voltage output unit, and an enable signal output from the actuator driving command unit; A second multiplier multiplying a unit pulse output from each of the second time delay units, a step input voltage output from the second step input voltage output unit, and an enable signal output from the actuator driving command unit; A third multiplier multiplying a unit pulse output from each of the third time delay units, a step input voltage output from the third step input voltage output unit, and an enable signal output from the actuator driving command unit; And an adder configured to add the result multiplied by each of the first, second, and third multipliers and output the result to the actuator driving voltage adjusting unit. The method of claim 2, And a time manager for managing a delay time of each of the first, second, and three hour delay units, wherein the robot actuator is configured to reduce overshoot of the robot actuator. The method according to any one of claims 1 to 3, The first overshoot reduction coefficients are T1, T2, and T3 according to Equation 3 below. The second overshoot reduction coefficient is A1, A2, A3 according to Equation 4 below, the overshoot reduction drive system for a robot actuator. [Equation 3] T ₁ = 0, T ₂ = Of , T ₃ = 2T ₂ (T ₁ , T ₂ , T ₃ are different delay times, w is the robot actuator resonant frequency, and ξ is the damping coefficient.) [Equation 4] A ₁ = 1 / (1 + 2M + M ² ), A ₂ = 2M / (1 + 2M + M ² ), A ₃ = M ² / (1 + 2M + M ² ), M = e ^{-ξπ /} (A ₁ , A ₂ , and A ₃ are step input voltages of different magnitudes.) A first step of detecting a damping coefficient and a resonant frequency of the robot actuator from the response result measured through the test drive of the robot actuator; A second step of calculating an optimal first and second overshoot reduction factor suitable for the robot actuator by driving a predetermined overshoot reduction factor calculation algorithm according to the damping coefficient and the resonance frequency detected in the first step; ; A third step of generating three step input voltages according to the first and second overshoot reduction coefficients calculated in the second step with a predetermined displacement input voltage applied to move the robot actuator by a predetermined displacement; A fourth step of adjusting the step input voltages of the third stage generated in the third step to the driving voltage level of the robot actuator; And a fifth step of driving the robot actuator with three step input voltages adjusted to the driving voltage level of the robot actuator in the fourth step. The method of claim 4, wherein the third process comprises; A third step of outputting first, second, and third unit pulses respectively delayed by different times based on a predetermined start time based on the first overshoot reduction coefficient calculated in the second step; 3-2 for simultaneously outputting the first, second, and third step input voltages having different magnitudes according to the second overshoot reduction coefficient calculated in the second process simultaneously with or in the third process. process; A third step of outputting a predetermined enable signal simultaneously with the steps 3-1 and 3-2 or in response to an actuator driving command from the outside; The first, second and third unit pulses respectively output in step 3-1, the first, second and third step input voltages output in step 3-2, and output in step 3-3 And a third to fourth process of interlocking the enable signal to generate a predetermined three-step step input voltage. The method of claim 6, wherein the step 3-4; A step 3-4-1 of multiplying the first unit pulse and the first step input voltage, the second unit pulse and the second step input voltage, and the third unit pulse and the third step input voltage, respectively; And a step 3-4-2 of generating a three-step step input voltage by adding the result value multiplied in step 3-4-1. . The method according to any one of claims 5 to 7, The first overshoot reduction coefficients are T1, T2, and T3 according to Equation 3 below. The second overshoot reduction coefficient is A1, A2, A3 according to Equation 4 below, the overshoot reduction driving method of the robot actuator. [Equation 3] T ₁ = 0, T ₂ = Of , T ₃ = 2T ₂ (T ₁ , T ₂ , T ₃ are different delay times, w is the robot actuator resonant frequency, and ξ is the damping coefficient.) [Equation 4] A ₁ = 1 / (1 + 2M + M ² ), A ₂ = 2M / (1 + 2M + M ² ), A ₃ = M ² / (1 + 2M + M ² ), M = e ^{-ξπ /} (A ₁ , A ₂ , and A ₃ are step input voltages of different magnitudes.)