JPH01276316A - Damping controller - Google Patents

Abstract

PURPOSE:To suppress the vibrations occurring at the tip of an arm body by selecting one of those signals outputted from plural control gain setters of different gain characteristics in response to the deviation between the arm angle and its target value and outputting said selected signal to an actuator which drives the arm body via an amplifier. CONSTITUTION:When the gain characteristics of a control gain setter 7A are set larger than those of a control gain setter 7B, the output of the setter 7A is selected with a large deviation set between an arm angle theta and its target value thetar. Thus the response having high conformity is obtained. While the deflection displacement is produced at the top of an arm body 2. In this respect, the output of the setter 7B is selected by a control gain selecting circuit 8 when the deviation between both angles theta and thetar is decreased. As a result, the resonance amplitude is attenuated at the top of the body 2 although the conformity is deteriorated. thus the vibrations can be suppressed at the tip of the body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration damping control device that is applied to machines having flexible arm bodies (for example, long arm robots, space structures, etc.).

[Conventional technology]

In general, when the length of a flexible arm increases, the tip bends and causes resonance, so in the past, for example, the thickness of the arm was increased to increase mechanical rigidity, or the use of acceleration sensors, strain sensors, etc. Vibration at the tip was suppressed through feedback control and other methods. However, if the mechanical rigidity is increased, the arm becomes larger and the 1.1 fil increases, which also increases the cost.Furthermore, feedback control using acceleration sensors, strain sensors, etc. requires a large number of sensors, and noise etc. There was also the problem of being easily influenced.

[Invention or problem to be solved]

As mentioned above, if the mechanical rigidity is increased as a method for suppressing vibration at the tip of the arm body, there is a problem in that the Tiffl of the arm body increases and the cost also increases. However, there were problems such as the need for an extra sensor.

The present invention was made in view of these problems, and
It is an object of the present invention to provide a vibration damping control device that can suppress vibrations at the tip of an arm body without requiring an extra sensor such as an acceleration sensor or a strain sensor, and without increasing the mechanical rigidity of the arm body.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a work machine including an arm body having a flexible structure and an actuator that drives the arm body, including an arm angle detector that detects the arm angle of the arm body, and an arm angle detector that detects the arm angle of the arm body; a target value generator that outputs a target arm angle value of the body; a subtracter that calculates the deviation between the arm angle target value output from the target value generator and the arm angle detected by the arm angle detector H1; , a plurality of control gain setters with different gain characteristics that input the output of this subtracter, and which one of the signals output from these control gain setters is used as the arm angle target value and the arm angle. The control gain selection circuit is characterized in that the control gain selection circuit selects the gain according to the deviation of the control gain and outputs the control gain to the actuator via an amplifier.

C operation] In the present invention, one signal is selected from among the signals output from a plurality of control cane setters having different cane characteristics according to the deviation between the arm angle target value and the arm angle,
This is output via an amplifier to the actuator that drives the arm, eliminating the need for additional sensors such as acceleration sensors or strain sensors, and suppressing vibration at the tip of the arm without increasing the mechanical rigidity of the arm. can do.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a vibration damping control device according to the present invention,
In the figure, reference numeral 1 denotes a working machine that includes a flexible arm body 2 to be controlled, and an actuator 3 that drives this arm body 2. Further, 4 is an arm angle detector that detects the arm angle θ of the arm body 2, 5 is a target value generator that outputs the arm angle target value θ of the arm body 2, and 6 is the target value output from the target value generator 5. arm angle! ” Target price θ
and the arm angle θ detected by the arm angle detector 4
This is a subtracter that calculates the deviation (θ - θ) from the

The output of this subtracter 6 is a control gain setter 7A.

7B, and is also input to a control gain selection circuit 8, which will be described later.

The control gain setters 7A and 7B set the control gain of the arm angle θ based on the signal input from the subtracter 6, and the signals output from these control gain setters 7A and 7B are used to select the control gain. The signal is input to a circuit 8, and the control gain selection circuit 8 selects only one of the signals. That is, the control gain selection circuit 8 selects the output of the control gain setter 7A when the deviation between the arm angle target value θ and the arm angle θ is larger than the set value ε, that is, when −θ −θ1r 〉,
When the deviation between arm angle target value θ and arm angle θ is smaller than set value ε, that is, −θ −r
rθ1≦ε,
At the time of ,: I+Ila+output of gain setter 7B is selected. Note that 9 is an amplifier that amplifies the output selected by the control gain selection circuit 8 and sends it to the actuator 3.

In FIG. 2, broken lines 21 and 22 indicate the control gain setter 7A when the arm body 2 is regarded as a rigid body.

7B shows the gain characteristics, and the solid lines 23 and 24 represent the arm body 2.
7 shows the gain characteristics of the control gain setters 7A and 7B, respectively, when the control gain setters 7A and 7B have a flexible structure. As shown in the figure, a control gain setter 7A and a control gain setter 7B
have different gain characteristics, and the gain characteristics of the control gain setter 7A are set larger than those of the control gain setter 7B.

When the gain characteristic of the control gain setter 7A is set larger than that of the control gain setter 7B in this way, when the deviation between the arm angle target value θ and the arm angle θ is large, the output of the control gain setter 7A is selected. Since the arm angle θ is selected, the response is as shown in the straight line part A in Fig. 3, and whether a well-coordinated response is obtained or not.
On the other hand, a deflection displacement occurs at the tip of the arm body 2 as shown by the solid line in FIG. 4, causing resonance at the resonant frequency. Therefore, when the deviation between the arm angle target value θ and the arm angle θ becomes small, by selecting the output of the control gain setter 7B by the control gain selection circuit 8, the arm angle θ is set as indicated by the broken line 31 in FIG. The response will be as shown, and the connectivity will be poor, but the broken line 4 in Figure 4 will be
As shown in 1, the resonance amplitude (deflection displacement) at the tip of the arm body
is damped, so vibrations at the tip of the arm body can be suppressed.

In addition, in the above embodiment, two control gain setters 7A, 7
Although B is used, three or more control gain setters may be used to suppress vibration at the tip of the arm body.

〔Effect of the invention〕

As explained above, the present invention provides a work machine including a flexible arm body and an actuator that drives the arm body, including an arm angle detector that detects the arm angle of the arm body, and an arm angle detector that detects the arm angle of the arm body. a target value generator that outputs an arm angle target value; a subtracter that calculates the deviation between the arm angle target value output from the target value generator and the arm angle detected by the arm angle detector; A plurality of control gain setters with different gain characteristics input the output of this subtracter, and any one signal from among the signals output from these control gain setters is used to set the arm angle target value and the arm angle. The present invention is characterized by comprising a control gain selection circuit that selects a gain according to the deviation and outputs the selected gain to the actuator via an amplifier. Therefore, one of the signals output from a plurality of control gain setters having different gain characteristics is selected depending on the deviation between the arm angle target value and the arm angle, and this signal is used to drive the arm body. By outputting the signal to the actuator via an amplifier, vibrations at the tip of the arm can be suppressed without requiring additional sensors such as acceleration sensors or strain sensors, and without increasing the mechanical rigidity of the arm.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the vibration damping control device according to the present invention, Fig. 2 is a diagram showing the gain characteristics of the control gain setter in the same embodiment, and Fig. 3 is a diagram showing the step input of the target value. FIG. 4 is a diagram showing the response of the arm when a target value is input in steps. FIG. DESCRIPTION OF SYMBOLS 1... Work equipment, 2... Arm body, 3... Actuator, 4... Arm angle detector, 5... Target value generator, 6... Subtractor, 7A, 7B... Control gain setting device,
8... Control cane selection circuit, 9... Amplifier. Applicant's representative Patent attorney Takehiko Suzue -

Claims (1)

[Claims] In a work machine equipped with an arm body having a flexible structure and an actuator that drives the arm body, an arm angle detector that detects an arm angle of the arm body, and a target value that outputs an arm angle target value of the arm body. a generator, a subtracter for determining the deviation between the arm angle target value outputted from the target value generator and the arm angle detected by the arm angle detector, and a gain characteristic whose input is the output of the subtracter. A plurality of control gain setters with different values and signals outputted from these control gain setters are selected according to the deviation between the arm angle target value and the arm angle, and the selected signal is sent to the actuator through an amplifier. A vibration damping control device comprising: a control gain selection circuit that outputs an output via a control gain selection circuit.