Robot Arm Joint-Space Paths for Stable End-Effector Posture
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Solution Overview
Problem
Existing robot motion path generation methods struggle to balance speed and reliability, particularly in environments with obstacles, often leading to unnecessary posture changes of the end-effector and inefficient energy consumption.
Innovation Solution
A robot system and control method that generate motion paths in the joint angle space of a multi-joint arm, suppressing posture changes of the end-effector while moving, using a path generation unit to create reliable paths efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If motion path is generated in joint angle space using conventional methods, then path generation speed is improved, but end-effector posture changes excessively causing energy waste
Solution Approach 1:
The patent transforms the motion path generation problem from Cartesian coordinate space to joint angle space, changing the parameter representation. By defining the motion path as a function of joint angles rather than end-effector coordinates, the system achieves faster computation while naturally constraining posture changes through the mathematical relationship between joint angles and end-effector orientation.
Solution Approach 2:
The patent introduces a new dimensional approach by formulating the motion path as a function f(θ) where θ represents joint angles. This dimensional transformation from position-based to angle-based parameterization enables the system to generate paths that inherently minimize unnecessary posture variations while maintaining computational efficiency.
2Reliability
If motion path is generated in joint angle space, then path generation reliability is improved, but end-effector posture control becomes more complex
Solution Approach 1:
By changing the parameter space from Cartesian coordinates to joint angles, the patent simplifies the control problem. The functional relationship f(θ) directly maps joint angle sequences to end-effector trajectories, providing reliable path generation while the mathematical formulation naturally handles posture constraints without adding control complexity.
3Ease of manufacture
If conventional path generation methods are used, then ease of implementation is maintained, but unnecessary posture changes occur leading to inefficient operation
Solution Approach 1:
The patent maintains implementation ease by using a functional approach f(θ) that can be integrated into existing robot control architectures. The method leverages the robot's inherent joint angle parameters and uses straightforward optimization techniques to generate efficient paths without requiring complex hardware modifications or sophisticated control algorithms.
Data Source
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AI summary
A robot system 1 includes: a robot 2 having a multi-joint arm 10 that changes the position of an end-effector; a path generation unit 110 that generates a motion path to move the end-effector; and a robot control unit 124 that operates the robot 2 so that the end-effector moves along the generated motion path; wherein the path generation unit 110 generates the motion path in a joint angle space of the multi-joint arm 10 while suppressing a posture change of the end-effector when moving along the motion path.