JPS60153514A - Control device of elastic arm - Google Patents

Abstract

PURPOSE:To speed up the attenuation of the vibration of an elastic arm while controlling the rotation of the elastic arm without increasing the gain of a closed loop controller by adding an opened loop controller to a control device for the elastic arm. CONSTITUTION:After setting the initial value of a truck forming part 5, the opened loop controller 4 outputs an opened loop driving signal so that the elastic arm 1 approaches a command value rapidly. The opened loop driving signal is inputted to the forming part 5, which calculates the time change of the rotation of the elastic arm 1 or the state variable of vibration which is the estimating variable by an estimating device 2. The deviation between the output of the forming part 5 and that of the estimating part 2 is inputted to the closed loop controller 3 and the controller 3 outputs a closed loop driving signal so that the output of the estimating device 2 coincides with that of the forming part 5. The closed loop driving signal is added to the opened loop driving signal to form a driving signal for the arm 1. The rotational speed of the arm or the attenuation speed of vibration can be adjusted by the controller 4.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method for controlling an elastic uniaxial arm such as a boom for attaching a manipulator or an artificial satellite antenna, while controlling the rotation of the arm and suppressing vibration. This invention relates to a control device for quickly damping.

[Jourai technology]

Conventionally, there was a device as shown in the block diagram of FIG. 1 as this type of device. In the figure, l is a uniaxial elastic arm, λ is an estimator that estimates the rotation and vibration state of the elastic arm C using sensor signals from a sensor (not shown) attached to this elastic arm l, and □3 is an estimator that estimates the rotation and vibration state of the elastic arm C. The drive shaft of the elastic animation l (
It is a closed-loop controller that provides a drive signal to the motor (not shown in the figure).

Next, the operation will be explained.The movement of the elastic arm 1 is controlled by a rotation angle detector (1) attached to the drive shaft of the elastic arm 1.
(not shown) and a strain detector (1 not shown) on the elastic arm l, and the detected sensor signal is input to the estimator 2. In the estimator, the elastic arm l
Using the mechanical model of the elastic arm l from the sensor signal of
The rotation angle and rotational angular velocity d of the elastic arm l, and the displacement and displacement speed of each vibration mode representing the vibration of the elastic arm l are estimated. Next, the deviation between each estimated variable and the command value is calculated and input to the closed loop controller 3, and the closed loop controller 3 generates a drive signal for the drive shaft of the elastic arm so that this deviation becomes O and outputs it. .

Since the conventional elastic □ arm control device is configured as described above, the gain of the closed loop controller must be increased in order to control the rotation of the elastic arm and speed up the damping of the vibration of the elastic arm. As a result, they had drawbacks such as being prone to instability and being susceptible to noise.

[Summary of the invention]

This invention was made to eliminate the drawbacks of the conventional ones as described above, and by adding an open-loop controller to the control device, it is possible to control the rotation of the elastic arm without increasing the gain of the closed-loop controller. An object of the present invention is to provide a control device for an elastic arm that can speed up the damping of vibrations of the elastic arm.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Second
The figure is a block diagram of one embodiment of the elastic arm control device according to the present invention, and in the figure, 1 to 3 indicate the same or equivalent parts as in FIG. 1. In the figure, Da is an open-loop controller, and S is a trajectory generation unit that generates a temporal change in the state quantity of rotation and vibration of the elastic arm l, that is, a trajectory, using an open-loop drive signal that is the output of this open-loop controller. Reference numeral 6 denotes an initial value setting unit that determines the initial value of the trajectory generation unit S at the start of open loop control.

Next, the operation will be explained. At the start of control, the output of the estimator Y is inputted into the initial value setting section B after setting the initial value.
sets the initial value of the state quantity of the trajectory generating section S using this value. For this reason, the estimator is operated steadily before starting open-loop control by the open-loop controller. After setting the initial value of the trajectory generating section S, the open loop controller DA outputs a drive signal in an open loop so that the elastic arm 1 quickly approaches the command value. This open loop drive signal is transmitted to the trajectory generator 5
, and there, time changes in the state quantities of the rotation and vibration of the elastic arm, which are the estimated quantities of the estimator l, are calculated from the dynamic model of the elastic arm l. The deviation between the output of the trajectory generation section S and the output of the estimator is inputted to the closed loop controller 3, and the closed loop controller 3 applies a closed loop drive signal so that the output of the estimator becomes equal to the output of the trajectory generation section S. Output. By adding this closed-loop drive signal and open-loop drive signal, the elastic arm l
The drive signal is

Here, the open loop controller DA does not use the feedback amount from the elastic arm l except for inputting the initial value of the trajectory generating section S through the initial value setting section 6, and gives a drive signal in an open loop. . The closed-loop controller 3 has the role of giving a correction amount so that the elastic arm l moves as planned by the open-loop controller, and the rotation of the elastic arm l and the speed of vibration damping are controlled by the open-loop controller. It can be adjusted in Hiro.

Various algorithms can be considered for this open-loop controller, such as the minimum time side and the minimum energy law.

Note that in the above embodiment, the estimator λ is used.
However, there is no particular need to use an estimator, and if an estimator is not used, the trajectory generating section S may generate the same signal as the sensor signal. Furthermore, although the open-loop controller t is shown as using the feedback signal from the trajectory generating section, open-loop control may be performed using only the command value and the initial value without using the feedback signal. Furthermore, in the case of an artificial satellite, the drive shaft of the elastic arm may be the satellite body (if a rotational torque is applied to the satellite body by a thruster or wheel, the same effect as in the above embodiment can be achieved).

〔Effect of the invention〕

As described above, since the present invention is configured so that an open loop controller is attached to the elastic arm control device,
Without increasing the gain of the closed-loop controller, it is possible to speed up the attenuation of the vibrations of the elastic arm while controlling the rotation of the elastic arm.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional elastic arm control device, and FIG. 2 is a block diagram showing an embodiment of the elastic arm control device according to the present invention. L...Elastic arm, U...Estimator, 3...Closed loop controller, Ri...Open loop controller, S...Trajectory generation unit, 6...
Initial value setting section. In addition, in the figures, the same symbols indicate the same or equivalent parts.

Claims (1)

[Claims] An elastic arm control device connected to a closed-loop controller includes an open-loop controller that outputs an open-loop drive signal to bring the elastic arm closer to a command value, and an open-loop controller that outputs an open-loop drive signal to bring the elastic arm closer to a command value; and an initial value setting section for setting an initial value of the trajectory generating section, and the output of the elastic arm is made equal to the output of the trajectory generating section. The elastic arm control device is characterized in that the closed loop controller outputs a closed loop drive signal (12), and adds the open loop drive signal to the closed loop drive signal to obtain a drive signal for the elastic arm.