Elastic Robot Movement Controller Path Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multiaxial robot control systems fail to adequately compensate for mechanical elasticities, friction, and inertia, leading to insufficient positioning accuracy, especially during highly dynamic operations.
Innovation Solution
A control method that calculates path correction values based on a dynamic robot model, accounting for elasticity, friction, and inertia, and applies these corrections to the robot's axis coordinates to compensate for dynamic positioning errors, using internal torque values and external torques, with temperature-dependent model parameters for precise compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional robot control systems are used with basic elasticity compensation, then the system structure remains relatively simple, but positioning accuracy is insufficient during highly dynamic operations
Solution Approach 1:
The control method pre-calculates correction values for path deviations caused by elasticities, friction, and inertia before executing the robot path. By computing these corrections in advance based on a dynamic robot model, the system compensates for dynamic errors without requiring complex real-time measurement and feedback mechanisms, thus improving positioning accuracy while maintaining reasonable system complexity
Solution Approach 2:
A dynamic robot model is introduced as an intermediary computational layer between the path planner and the robot controller. This model predicts the effects of elasticities, friction, and inertia, allowing the system to pre-calculate compensation values that improve positioning accuracy without directly modifying the physical robot structure or adding complex hardware
2Measurement precision
If axis controllers are adjusted to compensate for mechanical elasticities, then positioning accuracy improves slightly, but friction and inertia effects remain uncompensated
Solution Approach 1:
The control method integrates compensation for multiple error sources (elasticities, friction, and inertia) into a single unified control approach. By using a dynamic robot model that accounts for all these factors simultaneously, the system provides comprehensive compensation capability that works across different operating conditions and robot configurations, enhancing both adaptability and positioning accuracy
3Productivity
If the robot operates at high speed with dynamic movements, then productivity increases, but positioning accuracy deteriorates due to uncompensated dynamic errors
Solution Approach 1:
The control method pre-calculates correction values for path deviations that will occur during dynamic robot movements. By computing these corrections in advance based on a dynamic robot model that accounts for elasticities, friction, and inertia, the system maintains positioning accuracy even when the robot operates at high speeds, thus resolving the contradiction between productivity and precision
Data Source
AI summary
A predetermined robot path includes a plurality of path points defined by spatial coordinates. Spatial coordinates of the individual path points are converted in accordance with inverse robot kinematics into corresponding axis coordinates, the axis coordinates representing the position of the individual robot axes at respective path points. Axis-related controllers are actuated for individual robot axes in accordance with converted axis coordinates. Axis-related drive motors in individual robot axes are actuated by at least associated axis-related controllers. Path correction values are determined for individual path points on the robot path in accordance with a dynamic robot model, the path correction values taking account of the elasticity, friction, and/or inertia of the robot. Corrected axis coordinates are determined for the individual path points from uncorrected axis coordinates of individual path points and path correction values. The axis-related controllers are actuated with at least corrected axis coordinates.