Redundant Robot Manipulator Pose Control for Force Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robot systems with redundant manipulators face challenges in accurately applying and measuring forces and moments at the distal end, particularly in singular poses where external forces are not effectively mapped to joint moments, leading to inefficiencies in force application and detection.
Innovation Solution
A robot system with a control unit that determines the components of the transpose Jacobi matrix to optimize the pose of redundant links in the null space, ensuring that external forces and moments are effectively applied and detected by maximizing the vector norm of the transpose Jacobi matrix components, thereby preventing singular poses and enhancing force application and detection capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the robot manipulator operates in singular poses, then the structure is compact and reachable, but external forces are not effectively mapped to joint moments leading to poor force detection and application
Solution Approach 1:
The control unit proactively determines the transpose Jacobian matrix components and evaluates their metrics before force application or detection operations. By predicting potential singular pose issues and adjusting the null space pose in advance, the system prevents force mapping degradation rather than reacting to it after occurrence.
Solution Approach 2:
The system continuously monitors the metric of the transpose Jacobian matrix components and uses this feedback to adjust the null space pose. When the metric indicates approaching a singular configuration, the control unit modifies the pose to maintain optimal force mapping, creating a closed-loop control system that adapts to changing operational conditions.
2Force
If redundant links are moved in zero space to optimize force mapping, then force application and detection improve, but the control computation complexity increases
Solution Approach 1:
The system applies optimization only to the null space components of the redundant links, leaving the primary task space positions unchanged. By locally optimizing only the necessary degrees of freedom (those in null space), the system improves force mapping without requiring complete reconfiguration or complex global optimization.
Solution Approach 2:
The control unit changes the pose parameters of redundant links in the null space to optimize the metric of the transpose Jacobian matrix. By adjusting these specific parameters while maintaining task space positioning, the system achieves improved force mapping efficiency without compromising the primary operational task.
3Reliability
If the robot manipulator avoids singular poses through null space adjustment, then force mapping improves, but the flexibility to reach certain positions is reduced
Solution Approach 1:
The system dynamically adjusts the null space pose based on real-time evaluation of the transpose Jacobian matrix metric. Rather than statically avoiding singular poses, the system continuously adapts the redundant link configurations to maintain optimal force mapping while preserving task space reachability, allowing flexible adaptation to different operational requirements.
Data Source
Figure 1~2
AI summary
The invention relates to a robot system (1) having a robot manipulator (3), a control unit (5) and an operating unit (7), wherein the robot manipulator (3) comprises members (9) having degrees of freedom which are at least partially redundant relative to each other, the operating unit (7) being designed to detect an input of a user with respect to at least one selected direction of a force, the control unit (5) being designed to determine components, associated with the respective selected directions, of a transposing of a Jacobian matrix for a predefined position and/or orientation of the distal end (11) of the robot manipulator (3) in the zero space such that a first metric fulfils one of the following criteria on the basis of the components: not equal to zero, greater than a predefined limit value, maximum; and wherein the control unit (5) is designed to control the robot manipulator (3) in order to assume a pose according to the determined components.