SU883865A1 - Vibration stand control device - Google Patents

Description

one

The invention relates to control and regulation, and is intended to control vibration tests of objects using computing devices.

A device for controlling random vibration tests of products is known, comprising a multichannel closed loop control system, an intermediate memory block and a C AND switch.

The disadvantages of this device are in-. The low speed and low accuracy of reproduction of the vibration state of an object are observed.

The closest to the proposed technical solution is a device for controlling the vibrostand, comprising a series-connected vibration characteristics calculating unit and a comparison unit associated with the vibrostand input with the object, as well as an object vibration sensor, the output of which is connected to the first input of the vibration characteristics calculating unit, the second the input of which is connected to the second input of the comparator unit, to the output of the vibration sensor of the vibrostand and through the matrix calculating unit - from the first

the input of the control signal calculation unit, the second input of which is connected to the output of the vibration characteristics calculating unit and the input of the recording unit, the output of which is connected through the amplifier to the third input of the comparison unit, the second amplifier input is connected to the output of the control signal calculation unit and

10 by the third input of the V2 vibration characteristics calculating unit.

The purpose of the invention is to simplify the device. The goal is achieved by the fact that in the device for controlling the vibrostand the second input: and the output of the matrix calculating unit are connected respectively to the output and the fourth input of the calculating unit

20 vibration characteristics.

The drawing shows a block diagram of the proposed device.

The device comprises a block 1 for calculating vibration characteristics,

25 comparison unit 2, vibration test bench 3, test object 4, first vibration sensor 5, second vibration sensor 6, о.Ok 7 signal recording and reproduction, amplifier 8, calculation unit 9

30 of the control signal and the unit 10 for calculating a matrix of probabilistic characteristics, for example, an electronics electronic computer. The device works as follows. The operation of the device includes three modes: identification, control and vibration tests. In the identification mode, the purpose of which is to obtain the matrices of the transfer functions of the vibrating machine 3 and the object 4, block 1 uses block 10 to form a scalar random process and, through comparison block 2, it sequentially supplies it to vibrating stand 3. Block 2. comparing, vibrating stand 3 and the first The vibration sensor 5 forms a normal servo-hydraulic adjustment circuit providing the corresponding movement of the vibrator table 3. The assignment of this control loop in other modes of operation is similar. The reaction of the vibrostand 3 and the object 4, which represents the output signals of the first 5 and second 6 vibration sensors, respectively, enters block 1, which by means of block 10 calculates the desired matrix of transfer functions. The latter are the initial parameter for the control mode, which serves to generate control actions at the input of the vibrostand 3 when the specified accuracy of the matrix of the probabilistic characteristics of the vibrostand 3 reaction with the reference one is reached. The reference matrix is determined by block 1 according to a given matrix of probabilistic characteristics of the output signal of the test object 4, calculated from the data, operation, and obtained in the identification mode of the matrix of its transfer functions. As a given matrix, one can use, for example, a matrix of spectral densities. In the control mode, using a mathematical model, reflecting the relationship between the matrix of the probability characteristics of the response of the vibration stand 3 and control 1 and the parameters of its input signal, block 1 using block 10 forms a random process of vibrations x (t) using the reference matrix and block 2 comparing it to the shaker 3. The response of the shaker 3 y {t) from the output of the first vibration sensor 5 enters unit 1 Block 1 using block 10 calculates estimates of the corresponding probability characteristics, compare It computes with the reference ones and calculates the vector side, to which the iterative algorithm for correcting the parameters of the random process of vibrations x (t) is applied. According to the corrected vector of controlled parameters, block 1 forms a new random process of vibrations x (t) and via block 2 compares it to the shaker 3. The iterations are performed until the conditions of the matrix of probabilistic characteristics of the process y (t) are met If the after-zero iteration the error vector does not exceed the permissible value, the correction of the parameters of the random process of vibrations x (t) is not carried out. In conclusion of the control mode, unit 1 records the generated control signal in block 7, and the reference matrix of probability characteristics in block 9 of the calculation. signal manager. In the vibration test mode, unit 7 delivers the generated vibration signal x (t) through amplifier 8 and comparison unit 2 to shaker 3. The shaker 3 response signal comes from the output of the first vibration sensor 5 to the input of block 10, where its probability characteristics are calculated. The elements of the latter in block 9 of the calculation of the control signal are subtracted from the corresponding elements of the reference matrix and form the control signal which enters the input of the amplifier 8 by the resulting error vector, varying the amplitude of the vibration signal accordingly. At the same time, in block 9 a stopping criterion is formed, which characterizes the degree of correspondence of the probability characteristics of the standard calculated in block 10 of the matrix. If the received stop criterion exceeds the permissible value, the corresponding signal from the output of block 9 to block 1 is received and the device is switched to the identification mode and then the control. At the end of the control mode, unit 1 overwrites the newly generated control actions signal x (t) into unit 7 for recording and reproducing the signal and returns the device to vibration test mode. The signals from the controlled points of the object 4, recorded by the second vibration sensor b, arrive at block 1, which, together with block 10, interrupting the information from the first vibration sensor 5 for the required time, processes the test data. The time of vibration tests sets the timer of the unit 1. Stopping the operation of the device oc is from the console of the unit 1. The use of the proposed device reduces the cost by about 60 thousand rubles. compared to the known by eliminating the Fourier transform calculation block. At the same time, the quality of control of tests is not actually reduced, since the call to block 10 when processing information from controlled points of an object occurs sporadically.

In addition, block 10 in identification and control modes allows unloading block 1 as compared to the known, where the Fourier transform calculating block calculates only the complex Fourier transform coefficients, and the matrix 1 evaluates the likelihood characteristics matrices.

For the basic object, there may be installed a Schenk vibration table control system.

Claims (2)

1. USSR author's certificate 0 №602806, cl. G 01 M 7/00, 1975. 2. USSR author's certificate for application number 2622563 / 18-24, cl. G 05 B 15/00., 1979 (prototype).