JPH082725Y2 - Robot degeneration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a functional degeneracy device applied to a controller of a robot servo system.

<Prior Art> FIG. 2 shows a conventional example of a servo system of a robot (reference document, Dobouesky, S. On the Adaptive Control of Robot).
ic Manipulators: The discrete time case, Proc.1981 J
oint Auto Cont. Conf.).

The servo system shown in FIG. 2 online adjusts the position gain K _p and velocity feedback gain K _v of the control system for the adverse effects on the robot caused by the non-linearity due to the change in posture of the robot and the non-linearity due to an unknown load. By doing so, it is intended to compensate. Therefore, the servo system is provided with a reference model device 102 and an adaptive control mechanism 103.

In FIG. 2, reference numeral 100 denotes a servo system input setter which outputs a time series command r (t). 101 is a robot and a driving device.

Reference numeral 102 is a reference model device of a desirable servo system based on a motion equation defined by characteristic parameters of the servo system.
The "servo system characteristic parameter" is a parameter that represents the motion of the servo system in which the reference model is ideal. Specifically, here, it is represented by the natural frequency ω _n and the damping coefficient ζ,
Set so that the characteristics of the servo system are as follows.

+ 2ζω _n + ▲ ω ² _n ▼ y = ▲ ω ² _n ▼ r (t) Based on this equation of motion, the reference model device 102 responds to the command r (t) from the input setting device 100 with an ideal position y,
Velocity and acceleration are output as the model response. 103
Is an adaptive control mechanism, and from the reference model device 102,
Error between real system and reference model device 102 (=-
) And ε (= y−x), the position gain K _p and the velocity feedback gain K _v are calculated. "Adaptive control mechanism"
Is a wide range of motion of the robot and various loads,
In order to maintain uniformly good performance, it is a mechanism that adjusts the gains K _p and K _v so that the performance of the robot closely matches the desired performance embodied in the reference model. 104 is an adjusting mechanism of the position gain K _p . 105 is a mechanism for adjusting the velocity feedback gain K _v . 110 is a comparator,
Output r (t) -x. 111 is a comparator, which constitutes a velocity feedback loop. 112 is a comparator,
Output (=-). 113 is a comparator, and ε
(= Y−x) is output.

<Problems to be solved by the invention> However, in the conventional technology, the speed detector of the servo system (
Signal detection) fails, the adaptive control mechanism 103 that receives an error via the comparator 112 and the adjusting mechanism 105 that receives the error output an erroneous signal. Therefore, the servo system could not be controlled well.

An object of the present invention is to provide a function degeneration device for a robot, which is capable of degrading the function with better performance in the case of a failure of a speed detector of a servo system.

<Means for Solving the Problem> Therefore, as shown in FIG. 1, the functional degeneration device for a robot according to the present invention substitutes the speed signal of the output of the reference model device 102, that is, the speed signal of the model, for the speed signal of the actual system. And a degeneration commander 201 that issues a command to the switching device 200.

<Operation> When the speed detector of the actual system fails, the degeneration commander
According to the instruction of 201, the switching device 200 causes the reference model device 102 to
Of the actual system is used instead of the speed signal of the actual system.

<Embodiment> An embodiment of the present invention will be described with reference to FIG.

In FIG. 1, parts 100 to 105 and 110 to 113 are the same as those in the conventional example shown in FIG.

Reference numeral 200 denotes a switching device, which selects a speed signal of the actual system or a speed signal of a model response from the reference model device 102 according to a command β from a degeneration commander 201 described later and outputs it to the adjusting mechanism 105 and the comparator 112. .

201 is a degeneration command device, which is activated by a human operator's instruction or a signal α from a failure diagnosis means when the speed detector of the robot 101 (that is, the speed detector of an actual system) fails, and a switching command β to the switching device 200. Is output.

The failure diagnosing means here is for diagnosing a failure of the speed detector of the robot 101, and for example, a method of determining the lower limit value of the speed signal or the rationality of the position signal x, etc., is adopted although it is not specified.

According to the function degeneracy device having the above configuration, when the speed detector of the robot 101 has a failure, the degeneracy command device 201 is activated by the signal α and issues a switching signal β to the switching device 200.
Then, the switching device 200 is activated by this command β, and outputs the speed signal of the response of the model to the adjusting mechanism 105 and the comparator 112 instead of the speed which is an erroneous signal. Therefore, better control than erroneous signal based control is performed based on the velocity signal of the model response.

<Effect of the Invention> According to the present invention, when the speed detector of the robot fails,
Since the speed signal of the response of the model is used instead of the speed signal of the erroneous signal, the stable operation of the robot servo system can be obtained. Further, when a human operator gives an instruction to the signal α to the degeneration commander, human judgment can be utilized for stable operation of the servo system.

[Brief description of drawings]

FIG. 1 is an explanatory view of a function degenerating device of a servo system as an embodiment of the present invention, and FIG. 2 is an explanatory view of a conventional example. In the drawing, 100 ... Input setting device 101 ... Robot and drive device 102 ... Reference model device 103 ... Adaptive control mechanism 104 ... Position gain adjustment mechanism 105 ... Velocity feedback gain adjustment mechanism 110, 111, 112, 113 ... Comparator 200 ... … Switching device 201… Degeneration commander

Claims (1)

[Scope of utility model registration request] 1. A first adjusting mechanism for multiplying a position gain by a deviation between an input command and a position signal of a robot,
A second adjustment mechanism that multiplies the velocity signal of the robot by a velocity feedback gain, and a value obtained by subtracting a multiplication value obtained by multiplying the velocity signal by the velocity feedback gain from a multiplication value obtained by multiplying the deviation by the position gain. When the servo system used as a command value to the robot has a motion equation defined by the characteristic parameters of the robot's servo system, and when the command is input, the robot's servo system moves ideally. Ideal position signal, ideal velocity signal, which indicates the position, velocity, and acceleration of
A reference model device that outputs an ideal acceleration signal, a first error obtained by comparing the robot position signal and the ideal position signal with the first comparator, and a second comparison between the robot speed signal and the ideal speed signal. In a servo system of a robot equipped with an adaptive control mechanism that adjusts the position gain and the velocity feedback gain based on the ideal acceleration signal and a second error obtained by comparing the velocity detector Sometimes, a switching device for switching to the ideal speed signal output from the reference model device instead of the robot speed signal input to the second adjusting mechanism and the second comparator, and a switching operation of the switching device. And a degeneration commander for causing the function degeneration device of a robot.