JPS5821284B2 - servo controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for coupling actuators and objects to be controlled that generate any type of force, such as one-dimensional, two-dimensional or even multi-dimensional vibration testing machines. The present invention relates to a servo system drive device comprising a communication section.

An example of a two-dimensional vibration tester will be explained as a conventional servo-based drive device.

The two-dimensional shaking table testing machine shown in FIGS. 1 and 2 drives a table 2 by an actuator 1 having two axes in the horizontal direction and four axes in the vertical direction.

Each actuator 1 and the table 2 (!-) are connected by a driving hydrostatic bearing joint 3, so that the table 2 can be simultaneously excited in the horizontal direction A and the vertical direction B.

4 is a servo valve, 5 is a static pressure bearing for guiding the table 2, 6 is an actuator for self-weight compensation, and 7 is a foundation.

In this example, a drive hydrostatic bearing joint is used as a joint between the table 2 and the actuator 1, but a link joint or the like may be used instead.

Further, the number of actuators may be arbitrary.

When the single-axis system of this actuator 1 is taken out, its configuration is shown in FIG.

In FIG. 3, servo amplifier 8 current amplifies the input control signal and supplies it to servo valve 4. In FIG.

The servo valve 4 controls the direction and flow rate of pressure oil supplied from the oil pressure source 9.

Actuator 1 is driven accordingly.

However, the fundamental problem here is what kind of control signal should be given to the servo amplifier 8.

In the case of a two-dimensional vibration testing machine as shown in Figs. 1 and 2, it is relatively easy to detect state quantities such as displacement, velocity, and acceleration of the actuator 1 used as a feedback element, but Since the table 2 moves two-dimensionally, it becomes difficult to detect the displacement signal of the table 2, which is the amount that should actually be controlled, and it is not possible to assemble a sufficient servo system 4.

In conventional one-dimensional vibration testing machines, the actuator and table are rigidly connected, so there is no practical problem in detecting the movement of the actuator and using it as a feedback signal instead of detecting the movement of the table. There wasn't.

However, in the case of the two-dimensional vibration testing machine described above, it is necessary to provide a joint such as a hydrostatic bearing joint or a link joint between the actuator 1 and the table 2.

The influence of the rigidity on control performance has become a problem that cannot be ignored.

When the connecting part of the joint is modeled, as shown in Fig. 4, the equivalent spring constant between actuator 1 and table 2 is 1, the control coefficient is B1, the equivalent mass of actuator 1 and table 2 is m and M, respectively. It can be expressed as

As the scale of the vibration testing machine increases, the rigidity of the connection between the actuator 1 and the table 2 decreases, and its natural frequency becomes so small that it falls within the operating frequency range of the vibration testing machine. Therefore, the influence on control performance becomes noticeable.

To explain this more specifically, when a step input is added as an input signal to a conventional vibration tester, the displacement of the actuator 1 shows a relatively good response as shown in Figure 5, but the table The displacement of 2 becomes very oscillatory.

Despite these circumstances, conventional multidimensional vibration testing machines only use the state quantities of displacement, velocity, and acceleration of the actuator as feedback elements of the control system, and no efforts have been made to date to address this problem. At present, no solution has been taken.

In view of the above points, the present invention controls the movement of a movable part with high performance even when the rigidity of the connecting part that connects an actuator and a movable part such as a table is low.

The object of the present invention is to provide a servo system drive device that can perform the following functions.

As a result of research and development in order to achieve the above object, the present inventors have discovered that state quantities such as displacement, velocity, and acceleration of the movable part, or relative displacement and relative velocity between the actuator and the movable part.

It has been found that feedback of relative state quantities such as relative acceleration is highly effective.

One aspect of the present invention is a servo control system that includes an actuator that generates force according to a control command, a movable part that is driven by the actuator, and a connecting part that has a flexible structure with low rigidity that connects the movable part and the actuator. In the drive system, the state quantity of the actuator and the state quantity of the movable part to which the driving force of the actuator is transmitted via the connection part of the flexible structure with low rigidity, or the signal corresponding to the state quantity, are transmitted to the servo drive system. A servo system drive device characterized in that it is provided as a feedback element of a system drive device.

Another aspect of the present invention is a servo system that includes an actuator that generates force in response to a control command, a movable part driven by the actuator, and a connecting part of a flexible structure with low rigidity that connects the movable part and the actuator. In the servo system drive system, the state quantity of the actuator and the relative state quantity between the actuator and the movable part to which the driving force of the actuator is transmitted via the connection part of the flexible structure with low rigidity are calculated as follows. A servo drive device characterized by being provided as a feedback element.

The present invention will be described in detail below with reference to the drawings.

FIG. 6 shows a control configuration diagram of a vibration testing machine equipped with a first embodiment of the apparatus of the present invention, and in the figure, the same reference numerals as in FIG. 3 are the same parts.

10 is an adder, 11 is an acceleration detector that detects the acceleration of actuator 1 and feeds it back to adder 10, 12 is a speed detector that detects the speed of actuator 1 and feeds it back to adder 10, and 13 is an actuator. A displacement detector 14 detects the displacement of table 2 and feeds it back to the adder 10, an acceleration detector 14 detects the acceleration of table 2 and feeds it back to the adder 10, and 15 detects the velocity of table 2 and feeds it back to the adder 10. A speed detector 16 that feeds back to the adder 10 is a displacement detector that detects the displacement of the table 2 and feeds it back to the adder 10.

In the first embodiment of the present invention, the displacement, velocity, and acceleration of the actuator 1 are detected and fed back by the detectors 11 to 13, and the displacement, velocity, and acceleration of the table 2 are detected by the detectors 14 to 16. , this is fed back, and FIG. 7 shows the response state of the table 2 and actuator 1 to which a step signal is added as an input signal.

As is clear from FIG. 7, the vibration of the table 2 has disappeared and the table 2 has shown a very good response.

FIG. 8 shows a control configuration diagram of a vibration testing machine equipped with a second embodiment of the apparatus of the present invention, and in this figure, parts with the same symbols as in FIG. 6 are the same parts.

In this second embodiment, the acceleration of the table 2 detected by the acceleration detector 14 and the acceleration are integrated once by the integrating circuit 17 for compensation in a control system having feedback of the displacement, velocity, and acceleration of the actuator 1. A speed signal corresponding to the speed of table 2 obtained by the above calculation is fed back.

In this embodiment, the response state of the actuator 1 and table 2 when a step input signal is applied is as shown in FIG.

The results in this case almost match the response results of the first embodiment described above.

From this, it can be seen that even if there is no feedback of the displacement of the table 2 and a signal obtained by once integrating the acceleration of the table 2 is used instead of the velocity of the table 2, the effect does not change.

FIG. 10 shows a control configuration diagram of a vibration testing machine equipped with a third embodiment of the apparatus of the present invention, and in the figure, the same reference numerals as in FIG. 6 are the same parts.

In this third embodiment, only the acceleration of the table 2 detected by the acceleration detector 14 is fed back for compensation to a control system having feedback of the displacement, velocity, and acceleration of the actuator 1.

In this embodiment, the response states of the actuator 1 and the table 2 when a step input signal is applied are as shown in FIG.

In this case too, the vibration of table 2. However, the responsiveness is somewhat worse than in the two embodiments described above.

However, if it is acceptable to sacrifice the responsiveness of the control system to some extent, the objective 1 can be achieved to some extent by simply using acceleration as the feedback element from Table 2.

FIG. 12 shows a control configuration diagram of a vibration testing machine equipped with a fourth embodiment of the apparatus of the present invention, and in the figure, the same reference numerals as in FIG. 8 are the same parts.

This fourth example is feedback from Table 2.

The means are the same as in the second embodiment shown in FIG.
Of the feedback from the actuator 1, the displacement and acceleration of the actuator 1 are detected by the detector 13.
A signal detected by the detector 11 is fed back, and a velocity signal obtained by integrating the acceleration from the detector 11 by an integrating circuit 18 is fed back as the velocity of the actuator 1.

In this embodiment, the response state of the actuator 1 and table 2 when a step input signal is applied is as shown in FIG.

This response result almost coincides with the response result of the first embodiment shown in FIG. 7 and the response result of the second embodiment shown in FIG.

From this, it can be seen that a signal obtained by integrating the acceleration signals of both the actuator 1 and the table 2 once may be used as the speed signal.

A two-dimensional vibration testing machine is driven by a large number of actuators 1 in both the horizontal and vertical directions, and its basic control system is, for example, the system shown in Figure 6. In the case of multi-axis drive, this system is also required. It is configured to control synchronization according to the following.

Furthermore, in the above case, an electro-hydraulic two-dimensional vibration tester as shown in FIGS. 1 and 2 was used as an example.
The present invention is applicable to one-dimensional shaking tables or even multi-dimensional shaking tables, and is generally applicable when any type of actuator drives some kind of load and the movement of the load is desired to be controlled with high performance. can also be applied.

As described in detail above, the present invention provides a servo drive device including an actuator, a movable part driven by the actuator, and a connecting part having a flexible structure with low rigidity that connects these parts.
Even if the rigidity of the connecting part is low, in addition to the state quantities of displacement, velocity, and acceleration of the actuator, the displacement, velocity, and
By feeding back the state quantity of acceleration to the input side, the movement of the movable part can be controlled with higher performance than in the past.

Furthermore, if the present invention is applied to a multidimensional vibration testing machine, its control performance can be improved.

[Brief explanation of drawings]

Figure 1 is a plan view of a two-dimensional vibration testing machine, which is an example of a conventional servo drive system, Figure 2 is a front view of Figure 1, and Figure 3 is a diagram of the two-dimensional vibration testing machine shown in Figure 1. Actuator 1
Figure 4 is a diagram showing the axis control system; Figure 4 is a model of the connection part of the two-dimensional vibration tester shown in Figure 1; Figure 5 is a diagram showing the step response of the conventional two-dimensional vibration tester; Fig. 6 is a control configuration diagram showing a first embodiment of the device of the present invention applied to a two-dimensional vibration tester, Fig. 7 is a diagram showing its step response, and Fig. 8 is a second embodiment of the device of the present invention. FIG. 10 is a control configuration diagram showing the third embodiment of the apparatus of the present invention, FIG. 11 is a diagram showing the step response, and FIG. 12 is a diagram showing the step response. 13 is a control configuration diagram showing a fourth embodiment of the apparatus of the present invention, and FIG. 13 is a diagram showing its step response. 1... Actuator, 2... Table, 3... Hydrostatic bearing joint, 4... Servo valve, 8... Servo amplifier, 10...
Adder, 11.14... Acceleration detector, 12.
15... Speed detector, 13, 16...
Displacement detector, 17.18...Integrator circuit.

Claims (1)

[Claims] 1. An actuator that generates force according to a control command;
In a servo-based drive device comprising a movable part driven by the actuator and a connecting part having a flexible structure with low rigidity that couples the movable part and the actuator, the state quantity of the actuator and the driving force of the actuator are rigid. A servo system drive device comprising, as a feedback element of the servo system drive device, a state quantity of a movable part or a signal corresponding to the state quantity, which is transmitted through a connecting part having a flexible structure with a low resistance. 2 an actuator that generates force according to a control command;
In a servo-based drive device comprising a movable part driven by the actuator and a connecting part having a flexible structure with low rigidity that couples the movable part and the actuator, the state quantity of the actuator and the driving force of the actuator and the actuator are provided. A servo system drive device, characterized in that the servo system drive device comprises, as a feedback element of the servo system drive device, a relative state quantity with respect to a movable part that is transmitted through a connecting part of a flexible structure with low rigidity.