S-Curve Motion Control for Stable Load Handling Trajectories
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Load handling devices in storage systems experience instability and oscillation during acceleration and deceleration on grid structures, leading to potential damage of items stored within, due to uneven wheel rotation and sudden changes in movement.
Innovation Solution
A method and system for generating a constraint-based, time-optimal motion control profile using an S-curve trajectory generator that calculates continuous jerk references for acceleration and deceleration segments, ensuring smooth and stable movement by predicting and adjusting velocity, acceleration, and jerk references over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional motion control is used for load handling devices on grid structures, then the device can move between positions, but instability and oscillation occur during acceleration and deceleration causing item damage
Solution Approach 1:
The patent applies parameter changes by implementing continuous jerk reference profiles instead of conventional step-change acceleration profiles. The motion control system modifies the jerk parameter continuously throughout the motion cycle, creating smooth transitions that eliminate oscillations and prevent item damage while maintaining reliable device operation.
2Object-affected harmful factors
If smooth motion profiles are implemented to reduce oscillation, then item damage is minimized, but motion time increases due to constrained acceleration and deceleration
Solution Approach 1:
The patent employs dynamics by implementing time-optimal control with continuous jerk profiles that adapt acceleration and deceleration rates dynamically throughout the motion cycle. The system calculates optimal jerk references that respect mechanical constraints while minimizing total motion time, achieving smooth operation without excessive duration through real-time parameter optimization.
3Stability of the object's composition
If continuous jerk reference profiles are used to achieve smooth motion, then oscillation is reduced, but control system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the motion profile into distinct phases (acceleration, constant velocity, deceleration) with continuous jerk transitions between them. This segmented approach allows the control system to manage complexity through structured phase-based control while maintaining continuous jerk references that ensure motion stability and eliminate oscillations.
Data Source
AI summary
A method for generating a trajectory to control the movement of a motion device, by: i) receiving a specification of the trajectory; ii) receiving at least one jerk constraint; and iii) using the at least one jerk constraint to generate a sequence of one or more trajectory segments the trajectory segments are generated based on predicting a value of a parameter using a root finding algorithm to find a root of an objective function, the objective function being an amount of positional deviation from a commanded position when the velocity reference and the acceleration reference is substantially zero and the root corresponding to the value of the parameter is less than a predetermined threshold.