Adaptive Repetitive Control of A Linear Oscillating Motor under Periodic Hydraulic Step Load
Xinglu Li1,2, Zongxia Jiao1,2, Yang Li1
1School of Automation Science and Electrical Engineering, Beihang University, Beijing 100191, China.
Sensors (Basel, Switzerland)
|February 26, 2020
Summary
This study introduces an adaptive controller to address waveform distortions in linear oscillating motors caused by hydraulic step loads. The new controller effectively compensates for nonlinearities and uncertainties, improving pumping capacity.
Area of Science:
- Mechanical Engineering
- Control Systems Engineering
Background:
- Linear oscillating motors are crucial for linear actuation systems, often used in electrohydraulic actuators.
- Periodic hydraulic step loads from pump rectification valves cause waveform distortions, reducing pumping capacity.
- Conventional proportional-integral-derivative (PID) control struggles with these step loads and system nonlinearities.
Purpose of the Study:
- To develop a robust control strategy for linear oscillating motors subjected to periodic hydraulic step loads.
- To mitigate waveform distortions and improve the pumping capacity of electrohydraulic actuators.
- To overcome limitations of existing control methods, such as heavy memory usage and noise sensitivity.
Main Methods:
- A nonlinear model was developed to identify periodic hydraulic loads.
- Fourier series approximation was used to decompose the loads into simpler terms.
- A practical adaptive controller was designed to estimate and compensate for uncertain terms and nonlinearities.
- A robust control term was incorporated to handle uncertain nonlinearities.
Main Results:
- The proposed controller effectively compensates for periodic hydraulic step loads and system uncertainties.
- Experimental results validate the controller's effectiveness in improving tracking accuracy and reducing waveform distortions.
- The controller demonstrates superior performance compared to conventional repetitive controllers, with reduced memory and noise sensitivity.
Conclusions:
- The developed adaptive and robust control scheme successfully addresses the challenges posed by periodic hydraulic step loads in linear oscillating motor-pump systems.
- The controller achieves a prescribed final tracking accuracy, enhancing the overall performance and efficiency of the system.
- This approach offers a viable solution for improving the reliability and performance of compact hybrid electrohydraulic actuators.
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