Robot Assembly Axis-Space Trajectory Control for Predictable Motion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robot control methods result in unpredictable and varying trajectories due to velocity-dependent interpolation, especially in redundant robots, leading to differing axial coordinates and increased computing load during path traversal.
Innovation Solution
A method for controlling robot assemblies involves determining and storing a trajectory in axis space based on specified cartesian poses, calculating control values during transit, and controlling the robot using these values to reduce trajectory variations and computing load, with options for renewed determination and correction to maintain accuracy and optimize path planning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If variable scanning of cartesian path is performed in velocity-dependent interpolation cycle, then robot can adapt to different velocities, but axial coordinates vary and trajectory becomes unpredictable
Solution Approach 1:
The patent pre-calculates and stores discrete trajectory points in axis space before robot execution. These pre-determined points serve as a fixed reference framework that ensures consistent trajectory reproduction regardless of velocity variations during actual robot operation.
Solution Approach 2:
The continuous cartesian path is segmented into discrete trajectory points that are pre-calculated and stored. This segmentation transforms the continuous path planning problem into a discrete set of reference points that can be reliably interpolated during execution, reducing variability.
2Ease of operation
If cartesian path is scanned in each interpolation cycle, then real-time control is achieved, but computing load increases during path traversal
Solution Approach 1:
The computationally intensive path scanning and coordinate transformation operations are performed in advance during program preparation. The results are stored as discrete trajectory points in axis space, eliminating the need for repeated real-time calculations during robot execution.
Solution Approach 2:
Instead of repeatedly calculating transformations from cartesian coordinates to axis coordinates during execution, the patent creates a copy of the trajectory data in the form of pre-calculated axis space points that can be directly used for control.
3Adaptability or versatility
If redundancy resolution is performed in interpolation cycle, then robot can operate with redundant degrees of freedom, but discretization causes varying axial coordinates
Solution Approach 1:
Redundancy resolution is performed in advance during offline program preparation rather than during real-time execution. The discrete trajectory points are calculated with consistent redundancy resolution, ensuring axial coordinate consistency across multiple executions.
Solution Approach 2:
The continuous redundancy resolution problem is segmented into discrete trajectory points that can be calculated offline with controlled discretization. This approach allows for more careful and consistent resolution of redundant degrees of freedom.
Data Source
AI summary
A method for controlling a robot assembly having at least one robotic arm. The method includes determining a trajectory in the axis space of the robot assembly on the basis of a path having a plurality of previously specified Cartesian poses of at least one robot-assembly-fixed reference, and determining control values in the axis space on the basis of said trajectory. The robot assembly is controlled on the basis of the control values.