Electric Motor Control Parameter Tuning for Stable Responsive Loops
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Solution Overview
Problem
Conventional control apparatuses for electric motors face challenges in adjusting control parameters to maintain stability and responsiveness, especially when secular changes occur in the motor and load characteristics, leading to unstable control and the need for re-adjustment.
Innovation Solution
The method involves computing and adjusting control parameters using frequency characteristics from torque commands to motor speeds, including present and secular changes, to stabilize fully-closed control loops and enhance responsiveness, by calculating speed-proportional and position-proportional gain ranges and selecting optimal gains for both stable and changed conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If control parameters are adjusted using conventional methods based on gain and phase characteristics, then the control stability is improved, but the responsiveness of the control system deteriorates
Solution Approach 1:
The patent changes the fundamental parameter used for control adjustment from gain and phase characteristics to frequency characteristics. By computing frequency characteristics from the torque command to motor speed relationship, the system can simultaneously optimize both stability and responsiveness through a different parameter space that captures the dynamic behavior more effectively.
Solution Approach 2:
The patent implements a feedback mechanism where the computed frequency characteristics are used to automatically adjust control parameters. The control parameter adjuster continuously monitors the frequency characteristics and modifies the control parameters accordingly, creating a closed-loop system that maintains both stability and responsiveness.
2Speed
If control parameters are adjusted to enhance responsiveness, then the speed of response is improved, but the stability of the control system deteriorates
Solution Approach 1:
By transitioning to frequency characteristics as the basis for parameter adjustment, the patent accesses a parameter space where both stability and responsiveness can be optimized together. The frequency characteristics provide a comprehensive view of system behavior across different operating conditions, enabling simultaneous improvement of both traits.
Solution Approach 2:
The patent makes the control parameter adjustment dynamic by continuously computing frequency characteristics and adapting parameters in real-time. This dynamic adjustment allows the system to maintain optimal performance across varying operating conditions, preventing the trade-off between stability and responsiveness that plagues static adjustment methods.
3Device complexity
If conventional control parameter adjustment methods are used, then the device complexity is reduced, but the adaptability to secular changes deteriorates
Solution Approach 1:
The patent implements a self-service mechanism where the control system automatically adjusts its own parameters by computing frequency characteristics and using the control parameter adjuster. This self-adjusting capability eliminates the need for manual re-adjustment when secular changes occur, significantly improving adaptability without adding substantial complexity to the control architecture.
Solution Approach 2:
The patent performs preliminary computation of frequency characteristics and control parameter adjustment in advance, before secular changes significantly impact performance. By continuously monitoring and pre-adjusting parameters based on computed frequency characteristics, the system proactively adapts to changing conditions rather than reacting to performance degradation.
4Manufacturing precision
If manual re-adjustment of control parameters is performed, then the manufacturing precision is maintained, but the loss of time increases
Solution Approach 1:
The control system performs self-adjustment by automatically computing frequency characteristics and modifying control parameters without human intervention. This eliminates the time loss associated with manual re-adjustment while maintaining control precision, as the system continuously adapts to secular changes in real-time.
Solution Approach 2:
The patent ensures continuous computation of frequency characteristics and continuous adjustment of control parameters, eliminating interruptions for manual re-adjustment. This continuous useful action maintains manufacturing precision without the time losses inherent in periodic manual intervention.
Data Source
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AI summary
A method, according to the present invention, of adjusting control parameters used in a control apparatus of an electric motor includes the steps of: computing a first frequency characteristic (Step 1); computing a present speed-proportional gain range (Step 2); computing a present mechanical-system characteristic constant (Step 3); computing a present proportional gain range (Step 4); computing a secular characteristic (Step 5); computing a secular speed-proportional gain range (Step 6); computing a secular proportional gain range (Step 7); and selecting proportional gain values (Step 8).