JPH0692077B2 - Artificial arm controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for an artificial arm used in an industrial robot or the like, and particularly to an artificial arm control for preventing destruction of the artificial arm due to abnormal vibration of a work or the like. Regarding the device.

(Background of the Invention) Conventionally, in an artificial arm used for an industrial robot or the like,
When collaborating with another dedicated transfer / processing device or other artificial arm, vibration is propagated to the artificial arm when it contacts or grasps the vibrating workpiece or when the workpiece being grasped starts vibrating. There is an inconvenience that damage may occur due to excessive stress of the constituent members. In particular, in a multi-joint artificial arm, resonance may occur in a specific link, which may cause deterioration that cannot be immediately recognized due to stress fatigue, which may be very dangerous for security. In the case of an artificial arm that works in fluid,
There are many cases in which the work arm vibrates due to pressure waves propagating in the fluid and causes excessive stress in the artificial arm.

(Object of the invention) The present invention has been made in view of the problems in the above-described conventional type, and in the artificial arm control device, when the artificial arm contacts the work or grasps the work, The purpose is to prevent the destruction of the artificial arm based on the concept that the applied acceleration is detected and the artificial arm is immediately separated from the work when the acceleration exceeds a predetermined value.

(Structure of the Invention) In order to achieve the above-mentioned object, an artificial arm control device of the present invention comprises: a driving means for driving an artificial arm; and a driving means for approaching and grasping a work of the artificial arm. A main control unit that outputs an approaching / grasping control signal and generates and outputs a releasing / leaving control signal for releasing and releasing the artificial arm from the work based on the approaching / grasping control signal, The main control unit stores the release / separation control signal output from the main control unit, and outputs the release / separation control signal to the drive unit under unique control not by the main control unit. An independent emergency control sub-control unit, means for detecting the frequency and amplitude of the arm girder of the artificial arm, comparison means for generating a detection signal when the detected value exceeds a predetermined value, and this detection signal Main control Switching means for switching the output from the unit to the output from the sub-control unit and outputting the output to the drive means.

According to this, a release / departure control signal is generated and stored based on the approach / grasping control signal for driving the artificial arm, and when the arm girder acceleration of the artificial arm exceeds a predetermined value and is in an abnormal state. Is released from the control of the main control unit, and the stored release / separation control signal is independently output to the drive unit under the control of the sub control unit. This unique control means, for example, a real-time signal for outputting a release / release control signal is generated independently of the main control unit, and the release / release control signal is generated at a timing based on this real-time signal. The control is such that it is output to the drive means. The real-time signal is generated by, for example, extracting a synchronization timing signal included in the release / separation control signal output from the main control unit and synchronizing it with the approach / grasping control signal output from the main control unit based on this. This is a well-known technique.

Here, the release / separation control signal is, for example, a signal for performing an operation of tracing the operation of the artificial arm based on the approach / grasping control signal up to the present time. Therefore, at the time when the abnormal frequency and amplitude are detected, the release / withdrawal control signal that reversely traces the operation of the artificial arm in the normal state up to then is stored. -There is a high possibility that the signal is such that a detachment operation is performed. Then, the sub-control unit can convert the release / separation control signal based on the approach / grasping control signal in such a normal state into a real time and output it to the drive means.

Therefore, according to the present invention, the abnormal acceleration of the artificial arm, such as when the runaway of the main control unit vibrates the work or when the runaway of the main control unit causes the artificial arm to vibrate regardless of the existence of the work. At this time, the runaway of the artificial arm is blocked, and the sub-control unit appropriately releases and separates the artificial arm to protect the artificial arm from destruction and the like.

(Specific Description of the Invention) The specific configuration and operation of the control device of the present invention will be described below.

(1) Artificial arm links (including links that form joints)
An acceleration transducer is provided on the to obtain a signal corresponding to the magnitude of vibration.

(2) A vibration frequency band which may occur and is harmful is filtered and extracted from the above signal, the amplitude value is compared with the set value, and when the amplitude value is exceeded, the excessive vibration detection signal is transferred to the switching means.

(3) When the control command for causing the artificial arm to approach or grasp the work is executed in the main control unit, a control command for releasing the work and a control command for releasing the work are generated and stored. This separation / release control command is transferred to and stored in a sub control unit other than the main control unit.

(4) When receiving the transfer of the excessive vibration detection signal, the switching means replaces the stored instruction in place of the command being executed.
The output from the main control unit to the driving means of the artificial arm is switched to the output from the sub control unit so that the release control command is executed. As a result, the artificial arm stops the approaching or grasping operation to the work and starts the operation of releasing from the work or releasing the work.

(Effect of the invention) In the case of an artificial arm, since the operation target cannot be specified, the external stress applied cannot be predicted. However, according to the present invention configured as described above, the external force other than the overload of the driving power is applied. On the other hand, the protection range against misuse can be expanded and the operational reliability can be improved. Further, according to the present invention, it is possible to perform effective protection against damage such as repetitive stress fatigue due to vibration that is less than an appropriate and inexpensive diagnostic means other than by overhaul inspection, and to improve safety. it can. The invention is thus particularly adapted to artificial arms in civil engineering, construction or marine fields, working together in complex systems. According to the present invention, further, it is possible to prevent the runaway from expanding due to the artificial eyes and the internal sensor losing their functions due to external stress and generating a false verification signal. Further, since the detachment control is performed by the sub-control unit, when the runaway of the main control unit B is involved in the vibration generation of the work or the runaway of the main control unit B causes the internal vibration regardless of the existence of the work. It is possible to protect the artificial arm from being destroyed even in the case of occurrence of.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of an artificial arm control device before the improvement leading to the present invention. In the figure, reference numeral 1 denotes an acceleration transducer having a known response f characteristic, which converts the vibration of the artificial arm into an electric signal. Reference numeral 2 denotes a bandpass filter that extracts a component of a specific frequency band of the vibration waveform. This bandpass filter 2
Switches a plurality of components connected in parallel, or uses a digital filter to externally set parameters to switch the pass band. Reference numeral 3 is a band filter scanning unit for sequentially switching a plurality of frequency bands, 4 is a set value register for storing a set value of an amplitude limit for each frequency band to protect the artificial arm, and a switching signal from the band filter scanning unit 3. The settling value for comparison is transferred to the comparator 5 in conjunction with.
These acceleration transducer 1, bandpass filter 2,
The bandpass filter scanning unit 3, the set value register 4, and the comparator 5 constitute an excessive vibration detection unit A.

A control operation command generation / storage unit 6 generates and stores a control command in response to an input from an external sensor (not shown), or stores the operation sequence thereof. Reference numeral 7 is a leaving command generation unit that generates a command for leaving control based on a group of control commands for approaching and grasping the work, and 8 and 9 are a group of control commands and leaving control for performing unit work, respectively. A control command temporary storage unit for temporarily storing commands and a departure control command temporary storage unit. The control operation command generation / storage unit 6, the leaving command generation unit 7, the control command temporary storage unit 8 and the leaving control command temporary storage unit 9 constitute a control unit B.

Further, the switching unit 10, the power control unit 11, and the actuator (actuator) 12 form a drive unit C. The switching unit 10 switches between a normal control command and a disengagement control command according to the trip signal from the comparator 5, and the power control unit 11 drives an actuator 12 such as a motor or a hydraulic valve.

Next, the operation of the artificial arm control device of FIG. 1 will be described with reference to the flowchart of FIG.

The control operation command generation / storage unit 6 constantly monitors an input from the external sensor, and when a signal from the external sensor is supplied, a control for causing the artificial arm to perform a unit work according to the signal. Generate an instruction. Subsequently, this control command is transferred to the control command temporary storage unit 8 and temporarily stored therein, and then it is determined whether or not there is a case where the work is contacted or grasped in this unit work. If neither contact with the work nor grasp is made, the control command temporarily stored in the control command temporary storage unit 8 is directly transferred to the drive unit C and the control command is executed.

On the other hand, if there is a case where the work is contacted or grasped, the leaving command control unit 7 is caused to generate a leaving command, and the leaving command is transferred to the leaving control command temporary storage unit 9 to be temporarily stored. Then, while determining whether or not the unit work is completed and monitoring the output of the comparator 5 of the excessive vibration detection unit A, the control commands temporarily stored in the control command temporary storage unit 8 are sequentially transferred to the drive unit C. To execute the control command. When the unit work is completed without the excessive vibration detecting section A detecting the excessive vibration, the operation is completed. On the other hand, if excessive vibration is detected during the unit work, the detachment control command temporarily stored in the detachment control command temporary storage unit 9 is transferred to the drive unit C, the artificial arm is detached from the work, and the operation ends. .

However, when the runaway of the main control unit B is involved in the vibration generation of the work or when the internal vibration is generated due to the runaway of the main control unit B regardless of the existence of the work, the separating operation is performed normally. There is a possibility not to be missed. Therefore, the present invention adopts the configuration shown in FIG. The apparatus shown in FIG. 1 differs from the apparatus shown in FIG. 1 in that a sub-control unit for controlling the detachment of the artificial arm is separated from the main control unit B. In the figure, 51 is a departure control command temporary storage unit, which corresponds to the departure control command temporary storage unit 9 in FIG. 1, and 52 is a common control unit of the sub-control unit D, which is shown in FIG. It operates similarly to the control command generation / storage unit 6 in the control unit B, and causes the switching unit 10 to output the departure control command stored in the departure control command temporary storage unit 51.

In this way, by performing the separation control by the sub control unit,
It is possible to protect the artificial arm from destruction even when the runaway of the main control unit B is involved in the vibration generation of the work or when the internal vibration is generated due to the runaway of the main control unit B regardless of the existence of the work. it can.

FIG. 4 shows a modification of the acceleration transducer 1 part. In this way, a signal corresponding to the acceleration can be extracted by analyzing the out-of-band component included in the output of the rotary encoder built-in transducer used as the internal sensor. In the figure, reference numeral 15 denotes a rotary encoder. The rotary encoder 15, the amplifier 16 and the low-pass filter circuit 17 constitute a conventional internal sensor, and generate an angular velocity signal, a phase shift signal, an absolute position signal and the like. Here, the wide-range component of the output of the amplifier 16 is taken out by the wide-range filtering circuit 18, and the level thereof is detected by the comparator 19, so that the excessive vibration detection signal is generated.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an artificial arm control device before the improvement leading to the present invention, FIG. 2 is a flowchart for explaining the operation of the artificial arm control device of FIG. 1, and FIG. 1
FIG. 4 is a block configuration diagram of an artificial arm control device according to an embodiment of the present invention which is an improvement of the device shown in FIG. 4, and FIG. 4 is a block configuration diagram showing still another modified example of the present invention. A ... Excessive vibration detection unit, 1 ... Acceleration transducer, 4 ... Settling value register, 5 ... Comparator, B ... Control unit, 6 ... Control command generation / storage unit, 7 ... Exit command generation unit , 8 ... Control command temporary storage unit, 9 ... Exit control command temporary storage unit, D ... Sub-control unit.

Claims (1)

[Claims] 1. A drive means for driving an artificial arm, and an approach / grasping control signal to the driving means so that the artificial arm approaches and grasps a work, and the approach / grasping control is performed. A main control unit that generates and outputs a release / release control signal for releasing and releasing the artificial arm from the work based on the signal, and a release / release control signal output from the main control unit is stored. At the same time, the release / separation control signal is output to the drive means by an independent control not performed by the main control unit, an emergency control sub-control unit independent of the main control unit, and the arm of the artificial arm. Means for detecting the frequency and amplitude of the digit, comparison means for generating a detection signal when the detected value exceeds a predetermined value, and output from the main control section for output from the sub-control section by this detection signal. Switch to before Artificial arm control apparatus characterized by comprising a switching means for outputting to the driving means.