Balanced Control System for Stability and Feasibility
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Solution Overview
Problem
Conventional controllers often face challenges in ensuring both stability and feasibility, particularly when dealing with human operators in control loops, as modifying the controller or its inputs can lead to instability or infeasibility, and replacing the controller is not always feasible.
Innovation Solution
A control system that detaches the original controller from the control loop and duplicates its operations with a secondary controller, using a product of a gain with the difference between control commands to balance stability and feasibility, allowing for a merged control that combines stable and feasible outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller is modified to ensure feasibility, then the control feasibility is improved, but the stability of the controller deteriorates
Solution Approach 1:
The controller is divided into two separate controllers: a first controller that ensures stability and a second controller that ensures feasibility. Each controller independently processes the control objective and generates control commands, allowing stability and feasibility to be addressed separately without interfering with each other's performance.
Solution Approach 2:
A duplicate (second) controller is created that copies the functionality of the first controller but is specifically designed to enforce feasibility constraints. This duplicate controller generates a feasible control command that can be combined with the stable control command from the first controller.
2Reliability
If the output of the controller is modified to ensure feasibility, then the control feasibility is improved, but the stability of the system deteriorates
Solution Approach 1:
The control commands from both the first controller (stable) and second controller (feasible) are merged into a single combined control command. This merging process integrates the stable control signal with the feasibility-enforcing signal, producing a final control output that simultaneously achieves both stability and feasibility without destabilizing the system.
3Reliability
If the controller is replaced altogether to ensure feasibility, then the control feasibility is improved, but the loss of the original stable controller deteriorates system stability
Solution Approach 1:
Instead of replacing the original controller, the system segments control functionality into two parallel controllers. The first controller preserves the original stable control logic, while the second controller adds feasibility enforcement capabilities. Both controllers operate simultaneously with their outputs combined.
Solution Approach 2:
A combination mechanism acts as an intermediary that receives control commands from both the first and second controllers, processes them together, and generates the final control output. This intermediary ensures that neither controller's output dominates completely, maintaining both stability and feasibility.
Data Source
AI summary
Systems and methods for a control system for controlling a machine including a first controller to generate a first control command according to an objective of control. A second controller to generate a control input as a combination of a second control command and a third control command. Wherein the second controller generates the second control command according to the objective of control, and generates the third control command using a product of a gain with a difference between the first control command and the second control command. A motor to control the machine according to the control input.