JP2006258700A - Excitation testing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excitation testing machine for accurately exciting a tested body from a low-speed region. <P>SOLUTION: The excitation testing machine has an actuator for actuating a tested body, and a controller 11 for controlling operation of the actuator and exciting the tested body at any excitation characteristic. The controller 11 comprises a target speed setting means 12 for setting a target speed as a control input value, an integrator 17 for integrating the target speed and calculating a target displacement, a speed detecting means 13 for detecting the speed of a hydraulic cylinder 3, an adder 14 for calculating a deviation part of the actual speed from the target speed, an integrator 16 for integrating the speed deviation part and calculating a feed forward correction part of the target displacement, an adder 18 for adding the feed forward correction part to the target displacement, a displacement detecting means 19 for detecting displacement of the hydraulic cylinder 3, and an adder 20 for calculating a deviation part of the actual displacement from the target displacement. The controller 11 outputs a signal corresponding to the calculated displacement deviation part to a servo valve 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a vibration testing machine that vibrates a test object with arbitrary vibration characteristics and tests its performance.

  This type of vibration testing machine is required to suppress the distortion of the vibration waveform and to reproduce the target vibration waveform correctly.

  In a conventional vibration testing machine, a control signal from a controller is input to a servo valve, and a hydraulic cylinder expands and contracts to vibrate a device under test (see Patent Document 1).

  The block diagram of FIG. 5 shows a schematic configuration of the controller.

  The controller includes a target displacement setting means 52 that sets a target displacement as a control input value, a displacement detection means 53 that detects the displacement of the hydraulic cylinder, an adder 50 that calculates a deviation between the target displacement and the actual displacement, and a calculation And an amplifier 51 that amplifies the displacement deviation, and outputs a signal corresponding to the amplified displacement deviation to the servo valve 55 via the voltage-current converter 56 to bring the displacement of the hydraulic cylinder closer to the target displacement. PID control is performed.

As a result, the vibration testing machine expands and contracts with the displacement characteristics set by the hydraulic cylinder, and vibrates the device under test.
JP 2000-74780 A

  However, in such a conventional vibration testing machine, the target displacement is set as a control input value, and PID control is performed to bring the displacement of the hydraulic cylinder closer to the target displacement. When disturbance occurs, there is a problem in that fluctuations in speed and acceleration cannot be quickly suppressed.

  FIG. 6 is a characteristic diagram showing the results of simulating the displacement, speed, and acceleration of the hydraulic cylinder. As shown in this figure, the displacement of the hydraulic cylinder is increased or decreased temporarily with respect to the elapsed time, and as the direction of the displacement is switched, the hydraulic cylinder speed is reversed between positive and negative values, and the acceleration of the hydraulic cylinder is accelerated. Rises momentarily, but after this, fluctuations in the speed and acceleration of the hydraulic cylinder occur.

  Further, as a measure for improving the responsiveness of the feedback control, it is conceivable to increase the control gain that brings the displacement of the hydraulic cylinder closer to the target displacement. However, in that case, hunting may occur in a low speed region.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a vibration testing machine that vibrates a device under test accurately from a low speed range.

  The present invention is applied to a vibration testing machine that includes an actuator for driving a device under test and operates the actuator with arbitrary vibration characteristics.

  A target speed setting means for setting the target speed of the actuator; a speed detection means for detecting the actual speed of the actuator; a speed deviation calculating means for calculating a deviation between the target speed and the actual speed; and Feed forward correction calculation means for calculating the feed forward correction for the target displacement by integrating the deviation, target displacement correction means for adding the feed forward correction to the target displacement, and displacement for detecting the actual displacement of the actuator It comprises a detecting means and a displacement deviation calculating means for calculating a deviation between the target displacement and the actual displacement, and outputs a signal for causing the actual displacement to approach the target displacement in accordance with the displacement deviation. It was supposed to be.

  According to the present invention, the target speed is set as the control input value, the deviation between the target speed and the actual speed is integrated to calculate the feedforward correction amount, and the target displacement is added to the calculated feedforward correction amount. Since the correction is performed and the displacement of the actuator is controlled to be close to the target displacement, when a disturbance in speed occurs due to an external factor, the feedforward correction amount changes with good response, and fluctuations in speed and acceleration can be suppressed quickly. This makes it possible to reduce hunting by reducing the control gain that brings the displacement of the actuator close to the target displacement, and the object to be tested can be vibrated from the low speed range with the target vibration characteristics.

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

  The vibration testing machine shown in FIG. 1 vibrates a device under test with predetermined characteristics, and this device under test is a hydraulic shock absorber mounted on a vehicle, for example.

  FIG. 1 shows a schematic configuration of a vibration testing machine. The vibration testing machine includes a frame 2 installed on the ground 1 and a hydraulic cylinder 3 fixed to the frame 2. Fixing jigs 9 and 10 for mounting a test object are fixed to the upper end of the hydraulic cylinder 3 and the frame 2, respectively. The lower part of the DUT not shown is connected to the mounting jig 9 and the upper part is connected to the mounting jig 10. When the cylinder rod 7 is displaced, compression and tensile force act alternately on the device under test, and the device under test is vibrated in the vertical direction.

  The vibration testing machine includes a hydraulic source 4 that supplies hydraulic pressure to the hydraulic cylinder 3 and a servo valve 5 that controls the hydraulic pressure supplied from the hydraulic source 4 to the hydraulic cylinder 3. A control signal from the controller 11 is input to the servo valve 5 via the voltage / current converter 6 to cause the hydraulic cylinder 3 to expand and contract. The controller 11 controls the operation of the hydraulic cylinder 3 to vibrate the device under test with an arbitrary vibration characteristic.

  The controller 11 includes a target speed setting unit that sets a target speed of the hydraulic cylinder (actuator) 3, a speed detection unit that detects the actual speed of the hydraulic cylinder 3, and the target. A speed deviation calculating means for calculating a deviation between the speed and the actual speed; a feedforward correction calculating means for calculating a feedforward correction for the target displacement by integrating the speed deviation; and this feedforward for the target displacement. Target displacement correction means for adding the correction amount, displacement detection means for detecting the actual displacement of the hydraulic cylinder 3, and displacement deviation calculation means for calculating the deviation between the target displacement and the actual displacement. In response to this, a signal for causing the actual displacement to approach the target displacement is output to the hydraulic cylinder 3.

  The block diagram of FIG. 2 shows a schematic configuration of the controller 11.

  The controller 11 includes a target speed setting means 12 that sets a target speed as a control input value, an integrator 17 that integrates the target speed, a speed detection means 13 that detects the speed of the hydraulic cylinder 3, and a target speed and an actual speed. , An amplifier 15 that amplifies the speed deviation, an integrator 16 that calculates the feedforward correction for the target displacement by integrating the amplified speed deviation, and the target displacement An adder 18 for adding the feedforward correction amount, a displacement detection means 19 for detecting the displacement of the hydraulic cylinder 3, an adder 20 for calculating the deviation between the target displacement and the actual displacement, and the calculated displacement deviation amount. And a signal corresponding to the amplified displacement deviation is output to the servo valve 5 via the voltage-current converter 6.

  FIG. 3 shows a more detailed configuration of the controller 11.

  In FIG. 3, reference numeral 35 denotes an actuator constituted by the voltage / current converter 6, the servo valve 5, the hydraulic cylinder 3, and the like.

  The speed signal, acceleration signal, and displacement signal detected by the displacement sensor 36 detected from the actuator 35 are output via the filter 37 and displayed on the monitor 38 and via the AD converter 39. To the control system of the actuator 35.

  The detected values of the hydraulic pressures P1, P2, and P1-P2 supplied to and discharged from the hydraulic cylinder 3 are displayed on the monitor 38, respectively.

  Reference numeral 31 is a signal generator, and 32 and 33 are maps in which target speeds are set. The target speed setting means 12 is constituted by these.

  The target speed signal output from the target speed setting means 12 is increased or decreased by 5% through the amplifiers 41 and 42 and displayed on the monitor 38 together with the speed signal of the hydraulic cylinder 3. As a result, during normal operation, the actual speed signal characteristics are displayed in a state sandwiched between the speed signal characteristics obtained by increasing or decreasing the target speed signal by 5%.

  The speed signal Xd output from the AD converter 39 is input to the adder 14 through the amplifier 43.

  A target speed signal output from the target speed setting means 12 is input to the integrator 17 via the amplifier 44.

  The displacement signal X output from the AD converter 39 is input to the adder 20 through the amplifier 45.

  A displacement deviation signal output from the adder 20 is output to the actuator 35 via the limiter 46, the filter 47, the adder 48, and the DA converter 49.

  The integrator 17 constitutes target displacement calculation means for calculating the target displacement by integrating the target speed. The adder 14 constitutes a speed deviation calculating means for calculating a deviation between the target speed and the actual speed. The integrator 16 constitutes a feed forward correction calculation means for calculating a feed forward correction for the target displacement by integrating the speed deviation. The adder 18 constitutes target displacement correction means for adding the feedforward correction amount to the target displacement. The adder 20 constitutes a displacement deviation calculating means for calculating the deviation between the target displacement and the actual displacement.

  As described above, the controller 11 of the vibration tester sets the target speed as the control input value, integrates the deviation between the target speed and the actual speed, calculates the feedforward correction amount, and calculates the target displacement. The feedforward correction amount is added and corrected, and control is performed to bring the displacement of the hydraulic cylinder 3 closer to the target displacement. Therefore, when speed disturbance occurs due to an external cause, the feedforward correction amount changes with good response, and the speed and acceleration Fluctuations can be quickly suppressed.

  FIG. 4 is a characteristic diagram showing the results of simulating the displacement, speed, and acceleration of the hydraulic cylinder 3. As shown in this figure, the displacement of the hydraulic cylinder 3 increases or decreases temporarily with respect to the elapsed time, and the speed of the hydraulic cylinder 3 is reversed between positive and negative values as the direction of the displacement is switched. 3 rises instantaneously, but fluctuations in the speed and acceleration of the hydraulic cylinder after this are suppressed.

  This eliminates the need to increase the control gain that brings the displacement of the hydraulic cylinder 3 close to the target displacement to increase the response of feedback control. Therefore, it is possible to reduce the control gain and suppress hunting. It is possible to vibrate with a target vibration characteristic from a range.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The vibration testing machine of the present invention is not limited to a hydraulic shock absorber as a test object, and can be used for a test for vibrating other objects.

The schematic block diagram of the vibration testing machine which shows embodiment of this invention. Similarly block diagram. Similarly block diagram. The characteristic view which shows the result of having also simulated. The block diagram which shows a prior art example. The characteristic view which shows the result of having also simulated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Hydraulic cylinder 5 Servo valve 11 Controller 12 Target speed setting means 13 Speed detection means 14 Adder 16 Integrator 17 Integrator 18 Adder 19 Displacement detection means

Claims (1)

An actuator for driving the device under test;
In the vibration testing machine that operates this actuator with arbitrary vibration characteristics,
Target speed setting means for setting a target speed of the actuator;
Speed detecting means for detecting the actual speed of the actuator;
A speed deviation calculating means for calculating a deviation between the target speed and the actual speed;
A feed forward correction calculation means for integrating the speed deviation to calculate a feed forward correction for the target displacement;
Target displacement correction means for adding the feedforward correction to the target displacement;
Displacement detecting means for detecting an actual displacement of the actuator;
A displacement deviation calculating means for calculating a deviation between the target displacement and the actual displacement;
A vibration testing machine characterized in that a signal for bringing an actual displacement closer to a target displacement according to the displacement deviation is output to the actuator.

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