Redundant Actuator Control via Constrained Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for controlling redundant actuators in laser cutting machines face challenges such as mechanical crashes, unbounded tracking errors, and energy inefficiency due to the complexity of coordinating motions and neglecting physical constraints, leading to suboptimal cut precision and increased wear.
Innovation Solution
The system formulates the control of redundant actuators as an optimization problem, minimizing a cost function that includes constraints like reference trajectory adherence, velocity, acceleration, and torque limits, using time-varying and time-fixed constraints to ensure accurate and efficient motion, thereby reducing vibrations and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency separation method is used to control redundant actuators, then coordination between actuators is achieved, but fast actuator position constraint violations occur due to inappropriate cut-off frequency selection
Solution Approach 1:
The patent implements feedback control by continuously monitoring the actual positions of redundant actuators and adjusting control signals based on position errors. The control system compares desired positions with actual positions and modifies actuator commands to eliminate deviations, ensuring position constraints are maintained while achieving proper coordination between actuators.
Solution Approach 2:
The patent employs dynamic control strategies that adapt control parameters in real-time based on the system state. The controller dynamically adjusts gain parameters and control efforts according to the current position, velocity, and acceleration of actuators, enabling reliable coordination while preventing position constraint violations through adaptive response to changing system conditions.
2Measurement precision
If pseudo-inverse of Jacobian matrix is used to compute joint profiles, then kinematic positioning is achieved, but physical constraints are violated leading to unbounded tracking errors
Solution Approach 1:
The patent applies preliminary action by pre-computing feasible joint profiles that satisfy all physical constraints before execution. The control system calculates admissible velocity, acceleration, and torque limits in advance based on actuator capabilities and current state, then uses these pre-determined constraints to generate trajectory commands that inherently satisfy physical limits, preventing unbounded tracking errors.
Solution Approach 2:
The patent changes parameters by transforming the control approach from direct pseudo-inverse calculation to a constrained optimization framework. The system adjusts control parameters such as weighting matrices, constraint limits, and optimization objectives to balance trajectory tracking accuracy with physical constraint satisfaction, ensuring both precision and reliability are achieved.
3Productivity
If redundant actuators are used to reduce inertia, then productivity is improved, but control complexity increases due to coordination challenges
Solution Approach 1:
The patent applies universality by designing a unified control framework that handles multiple functions simultaneously: trajectory tracking, actuator coordination, constraint satisfaction, and optimization. The single control system performs all these functions through integrated algorithms, managing the complexity of redundant actuators while enabling high productivity through coordinated motion control.
Solution Approach 2:
The patent substitutes mechanical complexity with computational intelligence by replacing complex mechanical coordination mechanisms with software-based control algorithms. The control system uses advanced computation including optimization algorithms and real-time calculation to manage redundant actuators, replacing what would otherwise require complex mechanical linkages and synchronization mechanisms.
Data Source
AI summary
A method controls redundant actuators of a machine based on a reference trajectory. The method determines a cost function representing operations of the redundant actuators and minimizes the cost function subject to constraints to produce a sequence of commands for each actuator. The redundant actuators are controlled according to the sequences of commands.