Robot Lift Motion Planning Under Joint Torque Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current robotic motion planning methods do not adequately consider the mass and inertia of objects being lifted, leading to excessive strain and potential damage to robotic joints, requiring manual redesign and costly upgrades to handle heavy loads.
Innovation Solution
A computer-implemented method that adjusts robotic motion paths based on mass and torque limitations using a motion path searching algorithm, incorporating robot kinematics, mass data, and drive configuration data to determine feasible paths that avoid exceeding speed and torque limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If motion paths are planned based on minimal movement at high speed, then productivity is improved, but joint stress and torque exceedance occur
Solution Approach 1:
The system dynamically adjusts motion parameters including speed, acceleration, and path points based on real-time torque calculations and joint stress assessments, transforming static motion planning into a dynamic adaptive process that prevents torque exceedance while maintaining productivity
Solution Approach 2:
The system implements feedback by calculating torques at each path point, comparing them against torque limits, and automatically adjusting the motion path or speed when torque exceedance is detected, creating a closed-loop control system that prevents joint damage
2Reliability
If motion parameters are manually adjusted to reduce joint strain, then reliability is improved, but productivity decreases
Solution Approach 1:
The system performs self-service by automatically calculating torques, assessing joint stress, and adjusting motion parameters without manual intervention, enabling the robot to autonomously optimize its own motion planning while protecting its joints and maintaining productivity
3Reliability
If torque limits are strictly enforced through slower motion, then joint stress is reduced, but motion efficiency decreases
Solution Approach 1:
The system changes multiple parameters simultaneously including path points, speed profiles, and acceleration rates to find optimal motion trajectories that comply with torque limits while maintaining high motion efficiency, rather than simply reducing speed across all operations
4Force
If device is upgraded with stronger motors to handle heavy loads, then torque capacity is improved, but device complexity and cost increase
Solution Approach 1:
The system changes operational parameters including motion paths, speeds, and acceleration profiles to optimize torque utilization, allowing existing motors to handle heavy loads effectively without requiring upgrades to stronger, more complex, and more expensive motor systems
Data Source
AI summary
According to other embodiments, a method planning of motions to lift heavy objects using a robot system comprising a robot and an end effector, includes identifying data comprising (a) rigid bodies included in the robot and the end effector, (b) joints connecting the rigid bodies, and (c) torque limits for each of the joints. The torque limit for a joint indicates a maximum supported torque by a drive operating the joint. A motion path searching algorithm is applied to the input data to identify feasible robot paths. The motion path searching algorithm determines torque of each of joint when evaluating points for inclusion in a feasible robot path. An evaluated point is only included in a feasible robot path if the torque of each of the joints do not exceed the torque limits. At least one of the feasible robot paths is transferred to a controller associated with the robot.