Robot Arm Resistance Control for Easier Direct Teaching
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Solution Overview
Problem
Existing robot systems with robot arms face challenges in operability during direct teaching, as remotely controlling the robot arm is difficult and using a teaching pendant is not user-friendly, leading to fatigue and difficulty in precise movement with both hands or rough movement with one hand.
Innovation Solution
A robot system with contact detection and control mechanisms that adjust resistance based on the number of contact positions, allowing for impedance control to enhance operability by varying resistance levels when moving the robot with one or both hands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the robot arm is designed with brakes to prevent unexpected movement, then safety is improved, but operability during direct teaching deteriorates because the robot arm becomes difficult to move with human hand
Solution Approach 1:
The brake control system dynamically adjusts brake force based on operational context. During direct teaching mode, the control portion reduces or releases brake force when detecting hand contact, allowing easy movement. During automatic operation, full brake force is applied for safety. This dynamic adjustment resolves the contradiction between safety and ease of operation.
Solution Approach 2:
The system changes the brake force parameter according to the operational state. In direct teaching mode with hand contact detected, the brake force parameter is reduced or set to zero, enabling smooth manual movement. In other modes, the brake force parameter is increased to prevent unexpected movement, thus resolving the contradiction through parameter adaptation.
2Reliability
If resistance of the robot is increased to prevent unexpected movement, then safety is improved, but ease of operation during direct teaching deteriorates
Solution Approach 1:
The resistance force applied by the robot is dynamically adjusted based on operational mode and detected contact. During direct teaching with hand contact detected, resistance is minimized to allow easy movement. During automatic operation or when no contact is detected, resistance is increased for safety, resolving the contradiction through dynamic force adjustment.
Solution Approach 2:
The resistance parameter is changed based on operational context. In direct teaching mode, when hand contact is detected by contact sensors, the resistance parameter is reduced or set to minimum, enabling smooth manual operation. In other modes, the resistance parameter is increased to prevent unexpected movement, thus resolving the contradiction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides improved operability by allowing easy movement with one hand and precise adjustment with both hands, reducing user fatigue and enhancing the teaching process.
Implementation Method 1
a contact detection portion configured to output a signal in accordance with contact performed by a user
Implementation Method 2
The control portion is configured to control resistance of the robot applied to the user when the user moves the robot, in accordance with a number of contact positions at which the user contacts the robot, based on a signal from the contact detection portion
Data Source
AI summary
A robot system includes a robot and a control portion. The robot includes a contact detection portion configured to output a signal in accordance with contact performed by a user. The control portion is configured to control resistance of the robot applied to the user when the user moves the robot, in accordance with a number of contact positions at which the user contacts the robot, based on a signal from the contact detection portion.