Trajectory Blending Algorithm for Robotic Motion Control
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Solution Overview
Problem
Existing motion control algorithms fail to ensure accurate and rapid transitions between disparate motion paths in robotic applications, often resulting in undesired motion due to blending outside defined radii and asymmetrical trajectories.
Innovation Solution
An improved algorithm that calculates velocity profiles for each path segment, dividing them into blend-in, blend-out, and remainder regions, ensuring overlap between blend regions of successive profiles to minimize duration differences and reduce jerk, while allowing for symmetric motion trajectories and optimized blend radii to facilitate smooth transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional blending algorithms are used to transition between motion paths, then the motion transitions can be executed, but blending may occur outside the defined blend radius causing undesired motion and increasing execution time
Solution Approach 1:
The velocity profile is segmented into three distinct regions: blend-in region, blend-out region, and remainder region. This segmentation allows precise control over where blending occurs, ensuring it stays within the defined blend radius while optimizing execution time. The algorithm calculates the duration of each region separately and adjusts them to achieve accurate transitions.
Solution Approach 2:
The algorithm performs preliminary calculations to determine the optimal duration of blend-in and blend-out regions before executing the motion. By pre-calculating the timing parameters based on the velocity profile and blend radius constraints, the system ensures that blending occurs exactly within the desired radius without causing undesired motion or extending execution time.
2Reliability
If conventional blending algorithms are used, then motion transitions can be executed, but the trajectories become asymmetrical causing jerk and motion errors
Solution Approach 1:
The algorithm intentionally introduces asymmetry in the timing parameters of the velocity profile to compensate for the inherent asymmetry in the motion path. By calculating different durations for blend-in and blend-out regions based on the specific geometry of the path segments, the algorithm achieves symmetrical overall trajectory behavior, eliminating jerk and motion errors.
Solution Approach 2:
The algorithm dynamically adjusts the duration parameters of the velocity profile regions based on the specific motion context. It calculates the optimal duration for each region (blend-in, blend-out, remainder) by considering the velocity, acceleration, and geometric constraints, thereby achieving smooth and accurate transitions that maintain both reliability and precision.
3Stability of the object's composition
If the blend radius is increased to ensure complete blending, then transition smoothness improves, but the motion path length increases and productivity decreases
Solution Approach 1:
The algorithm dynamically determines the effective blend radius for each transition based on the velocity profile and motion parameters. Instead of using a fixed or overly conservative blend radius, the system calculates the minimum radius required to achieve complete blending within the available time, thereby maintaining transition smoothness while minimizing the impact on production speed.
Solution Approach 2:
The algorithm optimizes the blend radius parameter by calculating it based on the specific velocity and acceleration constraints of each motion segment. This dynamic parameter adjustment ensures that the blend radius is large enough to provide smooth transitions but not so large as to unnecessarily extend the motion path length, thereby maintaining both stability and productivity.
Data Source
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AI summary
The present invention relates to motion control and planning algorithms to facilitate execution of a series of moves within a motion trajectory. In one example, a trajectory is specified as a sequence of one or more path segments. A velocity profile is calculated for each of the one or more path segments, wherein each velocity profile is divided into a blend-in region, a blend-out region and a remainder region. Each path segment is executed such that the blend-in region of its velocity profile overlaps only with the blend-out region of the previous profile.