JP3631912B2 - Yawing control device for vibration test bench - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a yaw control device for a vibration test table, and more particularly to a yaw control device for a vibration test table for preventing yawing of a vibration test table that is accelerated and vibrated in one direction by a pair of two actuators.
[0002]
[Prior art]
Vibration tests are performed in various fields, and a vibration test stand is used for the vibration test. The ground, huge buildings and structures are subject to huge vibrational forces such as seismic waves. The ground vibration test is carried out by mounting a 1 / 50th scale and a 1 / 100th scale scaled ground on a bucket of a centrifugal loading device that generates 50 times and 100 times gravity equivalent. A vibration test stand is mounted on the centrifugal loading device, and the scaled ground is loaded on the vibration test stand.
[0003]
2. Description of the Related Art A vibration test stand that is capable of applying a vibration force on a straight line by two pairs of actuators is known. The two actuators reciprocate on one straight line with the same phase in synchronization with each other by the control mechanism. In the test bench that is vibrated by the known actuator, yawing occurs due to a slight phase shift between the two actuators, and rotational movement starts. Such yawing hinders high accuracy of the vibration test.
[0004]
It is desirable not to cause yawing in the vibration test bench. In particular, control that does not cause yawing in the control of the actuator is desired.
[0005]
[Problems to be solved by the invention]
The subject of this invention is providing the yawing control apparatus of the vibration test stand which does not produce yawing in a vibration test stand.
Another object of the present invention is to provide a yawing control device for a vibration test bench that does not cause yawing in a vibration test bench by incorporating control that does not cause yawing in the control of an actuator.
[0006]
[Means for Solving the Problems]
Means for solving the problem is expressed as follows. The technical matters corresponding to the claims in the expression are appended with numbers, symbols, etc. in parentheses (). The number, symbol, etc. clarify the correspondence / correspondence between the technical matters corresponding to the claims and the technical matters of at least one of the forms / implementations. It is not intended to show that the technical matter is limited to the technical matter of the embodiment.
[0007]
The yawing control device for a vibration test bench according to the present invention drives two actuators (2) and two actuators (2) for applying acceleration to the test bench (1) in two directions in the same direction. Electrical control system (23-1, 2), two displacement meters (12, 13) for measuring two displacement amounts at two locations on the test bench, and two locations on the test bench (1), respectively. The two accelerometers (14, 15) for measuring the two accelerations and their two displacement amounts are represented as dis1 (tk) and dis2 (tk), respectively, as two displacement amounts in the measurement time series, where k is a time-series order number, and the main difference between dis1 (tn) and dis2 (tn) represented by a number n greater than k is smaller than the main difference between dis1 (tk) and dis2 (tk). Mainly calculated main control electrical signal The main electric control system (21-1 and 2) for inputting to the electric control system (23-1 and 2) and two accelerations are acc1 (tk) and acc2 (tk) as two accelerations in the measurement time series, respectively. The sub-electric control signal (34) sub-calculated so that the sub-difference between acc1 (tn) and acc2 (tn) is smaller than the sub-difference between acc1 (tk) and acc2 (tk) It consists of a sub electrical control system (22) for superimposing on the electrical signal.
[0008]
The displacement, which is the integral of acceleration, is amplified by the acceleration deviation. Even if the displacement deviation is feedback controlled in real time, the resonance in the vibration system continues the rotational motion. However, by bringing the feedback acceleration deviation information into the control system with the displacement as a control variable in real time, the rotational motion is generated. Can be eliminated.
[0009]
Although n is preferably larger by 1 than k, an average value of past data can be used as a feedback signal. The sub-calculation is preferably executed based on (acc1 (tk) −acc2 (tk)) / 2. Appropriate weights can be applied to such difference information. The difference is not limited to the primary subtraction, and a secondary subtraction can be used. Various conventional means are known as means for the averaging process.
[0010]
In the sub-calculation, a value obtained by multiplying {(acc1 (tk) -acc2 (tk)) / 2} by a proportional constant is used as a sub-electric control signal, and the proportional constant is variable, and thus has various frequency characteristics. It is particularly preferable in that it can correspond to the vibration system it has and can appropriately suppress yawing. Various conventional means can also be used as a vibration exciter that is an actuator.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Corresponding to the drawing, the embodiment of the yaw control device for a vibration test bench according to the present invention is provided with an actuator for operating the vibration test bench. The vibration test bench 1 that is a heavy object is vibrated by two pairs of actuators 2. The two pairs of actuators 2 are formed of a first actuator 3 and a second actuator 4. The vibration test bench 1 is given a reciprocating force on the X axis on the external coordinate system XY independent of the vibration test bench 1 by a pair of two actuators 2.
[0012]
The vibration test bench 1 is vibrated by another pair of actuators 5. The other two pairs of actuators 5 are formed of another first actuator 6 and another second actuator 7. The vibration test table 1 is given a reciprocating motion force on the Y-axis on the external coordinate system XY independent of the vibration test table 1 by two pairs of actuators 5.
[0013]
The first actuator 3 and the second actuator 4 are respectively provided with pistons or piston rods 7 and 8 that reciprocate under the action of fluid pressure. The free ends of the piston rods 7 and 8 are connected to the vibration test table 1. The first actuator 6 and the second actuator 7 are respectively provided with pistons or piston rods 9 and 11 that reciprocate under the action of fluid pressure. The free ends of the piston rods 9 and 11 are connected to the vibration test table 1. An electric motor can be used in place of such a fluid pressure operating mechanism.
[0014]
The vibration test table 1 is supported by a guide system (not shown) so as to move in the X-axis direction by two pairs of actuators 2 and to move in the Y-axis direction by two pairs of actuators 5. The movement in the X-axis direction and the movement in the Y-axis direction are independent or dependent. A first X-direction displacement meter 12 and a second X-direction displacement meter 13 are provided independently of the vibration test bench 1, that is, fixed to the XY coordinate system. The first X-direction displacement meter 12 detects the X coordinate at a certain position of the vibration test table 1 or its X-direction displacement, and the second X-direction displacement meter 13 is the X coordinate at another position of the vibration test table 1 or its X-direction displacement. Can be detected.
[0015]
The vibration test table 1 is provided with a first X-direction accelerometer 14 and a second X-direction acceleration timepiece 15 fixed. The first X-direction accelerometer 14 can measure the X-direction acceleration at a certain position of the vibration test bench 1, and the second X-direction accelerometer 15 can measure the X-direction acceleration at another certain position of the vibration test bench 1. . The illustration of the Y direction displacement meter and the Y direction accelerometer is omitted. The X direction displacement and the X direction acceleration are measured in time series tk, and are measured substantially in real time. The time interval between adjacent time points on the time series tk is about 1 msec.
[0016]
When feedback control is performed using both displacement amounts measured by the first X-direction displacement meter 12 and the second X-direction displacement meter 13, the vibration system including the heavy object 1 has a rotational motion around the Z axis shown in FIG. That is, yawing occurs. In such yawing, when feedback control is performed using both accelerations measured by the first X-direction accelerometer 14 and the second X-direction accelerometer 15, yawing of the vibration system including the heavy object 1 can be avoided.
[0017]
An electric control system capable of avoiding such yawing is shown in FIG. The feedback electric control system shown in FIG. 3 includes a main electric control system 21 and a sub electric control system 22. The main electric control system 21 is formed of a first main electric control system 21-1 including the first actuator 3 and a second main electric control system 21-2.
[0018]
The first actuator 3 is subjected to feedback control (FB) by the first servo system 23-1. The second actuator 4 is feedback-controlled by the second servo system 23-2. A main control signal (not shown) and the FB signals 25-1 and 25-2 are input to the first servo systems 23-1 and 23-1.
[0019]
Main electric control systems 21-1, 2:
The first displacement voltage dis1 and the second displacement signal of the first displacement signal 26-1 measured by the first X-direction displacement meter 12 and the second X-direction displacement meter 13 and outputted from the first actuator 3 and the second actuator 4, respectively. The second displacement voltage dis2 of 26-2 is input to the first subtractor (Sum3), and a value (dis1-dis2) is calculated. The value is multiplied by ½ by a multiplier (Gain4). An FB voltage (in the figure, now) 27 corresponding to the calculated value is fed back.
[0020]
The FB voltage 27 and the voltage dis1 of the first displacement signal 26-1 are negatively added by the first negative adder (Sum6), and the signal after the negative addition is proportionally multiplied to obtain the first sub-control adder. (Sum9) 29-1. The same FB voltage 27 and the voltage dis2 of the second displacement signal 26-2 are negatively added by the second negative adder (Sum7), and the signal after the negative addition is proportionally multiplied to obtain the second sub control addition. Is input to the counter (Sum10 / subtraction) 29-2.
[0021]
Sub-electric control system 22:
The first acceleration voltage acc1 and the second acceleration 31 of the first acceleration signal 31-1 measured by the first X-direction accelerometer 14 and the second X-direction accelerometer 15 and output from the first actuator 3 and the second actuator 4, respectively. -2 of the second acceleration voltage acc2 is input to the second subtractor (Sum2), and a value (acc1-acc2) is calculated. The value is multiplied by ½ by a ½ multiplier. The value after this calculation is further multiplied by 10 / (25 * 980), and then further multiplied by a variable proportionality constant 10 by the variable multiplier 32, and the sub-control signal 34 after the calculation is The signals are input to a first sub-control adder (Sum9) 29-1 and a second sub-control adder (Sum10 / subtract) 29-2, respectively.
[0022]
Main / sub hybrid electric control system:
The first main / sub control electric signal 35-1 and the second main output from the first sub control adder (Sum9) 29-1 and the second sub control adder (Sum10 / subtract) 29-2, respectively. The sub-control electric signal 35-2 is input to the first servo system 23-1 and the second servo system 23-2 in principle. The first main / sub control electric signal 35-1 and the second main / sub control electric signal 35-2 are first and second weight signals 36 obtained by weighting some information obtained from the first actuator 3 and the second actuator 4. -1 and 36-2, and the final control state is adjusted.
[0023]
In such an electric circuit, the two displacement amounts are expressed as dis1 (tk) and dis2 (tk), respectively, as two displacement amounts in the measurement time series. Here, k is a time-series order number. The main control electric signal that is mainly calculated so that the main difference between dis1 (tn) and dis2 (tn) represented by the number n greater than k is smaller than the main difference between dis1 (tk) and dis2 (tk) is This is fed back to the main electric control system 21.
[0024]
Further, in such an electric circuit, the two accelerations are expressed as acc1 (tk) and acc2 (tk) as two accelerations in the measurement time series, respectively. The sub-electric control signal 34 sub-calculated so that the sub-difference between acc1 (tn) and acc2 (tn) is smaller than the sub-difference between acc1 (tk) and acc2 (tk) is the main / sub hybrid electric control system. Is superimposed on the main control electrical signal. By varying the rotation suppression gain GΨ (Ψ is equivalent to the rotational acceleration amount) which is a variable proportional constant of the variable multiplier 32, the control state of the hybrid control system in which the acceleration system control is incorporated in the displacement system control can be adjusted.
[0025]
Control method using acceleration values:
From the acceleration response values (acc1, acc2) of the two first actuators 3 and the second actuator 4, the Ψ rotational acceleration amount is calculated by the following formula:
Ψacc = (− acc1 + acc2) / 2. ... (1)
This Ψ rotation acceleration amount is FBed to the servo outputs (SV1, SV2) of the actuators (vibrators 1, 2) by the following equation to suppress Ψ rotation.
SV1 ′ = SV1 + GΨ * Ψacc, (2)
SV2 ′ = SV2-GΨ * Ψacc. ... (3)
This calculation is calculated by the circuit shown in FIG.
[0026]
simulation:
Various setting values are shown in the table of FIG. The frequency characteristics of the shaker 1 and the shaker 2 are changed by making the two set values KI and KFD different between the shaker 1 (first actuator 3) and the shaker 2 (second actuator 4). By changing, the vibration test stand 1 was positively caused to rotate, and the simulation of the hybrid FB control according to the present invention was performed. As a result of simulating the compensation effect of inhibition control when the Ψ inhibition gain was increased under the conditions shown in the table of FIG. 4, the following items were confirmed.
(1) Even when the characteristics of the two vibrators are slightly different, the frequency characteristics of the vibrators can be made uniform as the suppression gain is increased, and the Ψ rotation (amount) can be suppressed.
(2) When the Ψ compensation gain is increased, the system becomes unstable and enters a resonance state. As far as this simulation model is concerned, it is appropriate that GΨ is 10. Depending on the model, this value should preferably be variable.
[0027]
In FIGS. 5, 6, and 7, the horizontal axis represents time, and the vertical axis represents the displacement of the vibrators 1 and 2 and the rotational acceleration amount Ψ. In FIGS. 5, 6 and 7, (a) and (b) respectively show the results of two comparative values selected so that the results can be properly evaluated. 8, 9, and 10, the horizontal axis represents time, and the vertical axis represents the displacement of the vibrators 1 and 2. 8, 9, and 10, (a) and (b) show the results of two values (displacements) selected so that the results can be properly evaluated. The conditions of the vibration experiment for obtaining the results shown in FIGS. 8, 9, and 10 are inputs of 10 Hz and 1 cm.
[0028]
5 and 8 show the results when GΨ = 0 (corresponding to known control). In this case, as shown in FIG. 5, the difference value between the displacement amounts Model 1 and 2 of the vibrators 1 and 2 increases with time. It takes a long time to decrease Ψ. As shown in FIG. 8, the displacement amounts Model 1 and 2 of the vibrators 1 and 2 show different inherent characteristics at the same time.
[0029]
6 and 9 show the results when GΨ = 10. In this case, as shown in FIG. 6, with the passage of time, the difference value between the displacement amounts Model 1 and 2 of the vibrators 1 and 2 converges to zero. The time until Ψ decreases is short. As shown in FIG. 9, the displacement amounts Model 1 and 2 of the vibrators 1 and 2 are almost close to zero at the same time.
[0030]
7 and 10 show the results when GΨ = 15. In this case, as shown in FIG. 7, with the passage of time, the difference value between the displacement amounts Model 1 and 2 of the vibrators 1 and 2 converges to zero, and the time until Ψ decreases is short. This is almost the same as the case of = 15. When the value of GΨ increases, as shown in FIG. 10, the displacement amounts Model 1 and 2 of the vibrators 1 and 2 periodically vary in small increments, and in some cases, oscillate at a high frequency. End up.
[0031]
Such experimental results indicate that by adding the acceleration to the variable of the control function, an increase in the rotational acceleration amount ψ can be suppressed and converged in a short period of time. By changing the value of GΨ, it is possible to suppress oscillation that occurs as a result of control. The control of only the displacement prolongs the time of the FB control, but the time of the FB control can be shortened by adding the acceleration to the control variable.
[0032]
【The invention's effect】
The yaw control device for a vibration test bench according to the present invention effectively solves the problem of not causing yawing in the vibration test bench by incorporating a problem that does not cause yawing in the vibration test bench and a control that does not cause yawing in the servo system of the actuator. doing. In particular, it is possible to shorten the time until the generation of rotational acceleration is effectively suppressed.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of a yaw control device for a vibration test bench according to the present invention.
FIG. 2 is a front view of FIG. 1;
FIG. 3 is a control circuit diagram showing an embodiment of a yaw control device for a vibration test bench according to the present invention.
FIG. 4 is a data table showing experimental conditions.
FIGS. 5 (a) and 5 (b) are graphs showing experimental results when the control variable is zero.
6 (a) and 6 (b) are graphs showing experimental results in two modes when the control variable is 10, respectively.
FIGS. 7A and 7B are graphs showing the experimental results when the control variable is 15. FIG.
FIGS. 8A and 8B are graphs respectively showing experimental results of two other modes when the control variable is zero.
FIGS. 9A and 9B are graphs showing the experimental results when the control variable is 10. FIG.
FIGS. 10A and 10B are graphs showing experimental results when the control variable is 15. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Test stand 2 ... Two 1 pair actuator 3 ... 1st actuator 3
4 ... Second actuator 4
DESCRIPTION OF SYMBOLS 12 ... 1st X direction displacement meter 13 ... 2nd X direction displacement meter 14 ... 1st X direction accelerometer 15 ... 2nd X direction acceleration clock 21-1 ... 1st main electric control system 21-2 ... 2nd main electric control system 22 ... Sub-electric control system 23-1... First servo system 23-2. Second servo system 32. Variable multiplier 34 .. sub-electric control signal dis 1 (tk) ... displacement amount dis 2 (tk) ... displacement amount acc 1 (tk). Acceleration acc2 (tk) ... Acceleration

Claims (3)

Two pairs of actuators for applying acceleration in the same direction at two locations on the test table,
An electric control system for driving the actuator;
Two displacement meters for measuring two displacement amounts at two locations on the test table;
Two accelerometers for measuring the respective two accelerations at two locations on the test table;
The two displacement amounts are expressed as dis1 (tk) and dis2 (tk), respectively, as two displacement amounts in the measurement time series, where k is an order number in the time series and expressed by a number n greater than k. The main control electric signal that is calculated in such a manner that the main difference between dis1 (tn) and dis2 (tn) is smaller than the main difference between dis1 (tk) and dis2 (tk) is input to the electric control system. A main electric control system for
The two accelerations are expressed as acc1 (tk) and acc2 (tk) as two accelerations in the measurement time series, and the sub-difference between acc1 (tk) and acc2 (tn) is acc1 (tk) and acc2 (tk). A sub electric control system for superimposing the sub electric control signal sub-calculated so as to be smaller than the sub difference of the main control electric signal ,
N is one greater than k
Vibration test stand yaw control device. In claim 1,
The yaw control device for a vibration test stand, wherein the sub-calculation is executed based on (acc1 (tk) -acc2 (tk)) / 2. In claim 2 ,
In the sub-calculation, a value obtained by multiplying the {(acc1 (tk) −acc2 (tk)) / 2} by a proportional constant is used as the sub-electric control signal.
A yawing control device for a vibration test stand, wherein the proportionality constant is variable.

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