Robot End Effector Alignment Control for Precise Teaching
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Solution Overview
Problem
Existing robot teaching methods face challenges in accurately aligning the direction of robot fingers with a desired direction, particularly for tasks like inserting an object into a hole, due to difficulties in precise alignment and posture designation.
Innovation Solution
A control apparatus for a robot that includes a movable unit and a force detection unit, allowing for two control modes: one for direct teaching and another for automatic alignment, where the robot adjusts the end effector's position and angle based on detected forces and angles relative to predefined coordinate systems, ensuring accurate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a user performs teaching on the robot by applying external force to fingers to move and rotate them, then the robot can be taught force control, but it is not easy to accurately align the direction of the fingers with the desired direction
Solution Approach 1:
The system automatically calculates the relative angle between the moving coordinate system and object coordinate system, and provides feedback control by rotating the movable unit to make the relative angle closer to zero when it exceeds the threshold, enabling accurate alignment during robot teaching
Solution Approach 2:
The patent replaces manual mechanical alignment operations with an automated control system that uses coordinate system calculations and automatic rotation control to achieve precise alignment, reducing reliance on operator skill
2Ease of operation
If the robot operates in first control mode allowing movement and rotation according to detected force, then the robot responds naturally to user input, but the alignment precision is insufficient for tasks requiring accurate directional control
Solution Approach 1:
The system dynamically switches between first control mode (natural movement according to detected force) and second control mode (automatic alignment when relative angle exceeds threshold), adapting the control strategy based on real-time conditions to achieve both ease of operation and precision
Solution Approach 2:
The system changes the control parameter from pure force-based movement to angle-corrected movement by introducing relative angle calculation and threshold-based automatic rotation, transforming the control characteristics to achieve precise alignment
Data Source
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AI summary
A control apparatus (25) includes a control unit (54) that executes control of a robot (20), and a receiving unit (53) that receives an object coordinate system set for an object not a movable unit (A) and not moving or rotating with the movable unit (A). The control unit (54) has a first control mode (M01) in which the movable unit (A) is moved and rotated according to a detected force while the force is detected by a force detection unit (21), and a second control mode (M02) in which, when a relative angle between a predetermined first axis of a moving coordinate system moving and rotating with the movable unit (A) and a predetermined second axis of the object coordinate system is smaller than an angle threshold value, the movable unit (A) is rotated to make magnitude of the relative angle closer to zero.