The design and implementation of an accelerometer-assisted velocity observer

Area of Science:

• Control Systems Engineering
• Mechatronics
• Signal Processing

Background:

• Velocity estimation is crucial for precise motion control.
• Conventional state-space velocity observers (SSVO) are sensitive to accelerometer noise and offset.
• Existing methods may not offer optimal performance in dynamic environments.

Purpose of the Study:

• To introduce and evaluate a Dynamically Compensated Velocity Observer (DCVO).
• To compare the DCVO's performance against conventional SSVO and ITM-based estimators.
• To assess the DCVO's impact on sliding-mode controller performance and positioning accuracy.

Main Methods:

• Formulating the DCVO's sensitivity to acceleration measurement noise.
• Comparing DCVO with SSVO regarding accelerometer offset insensitivity.
• Implementing DCVO, SSVO, and ITM estimators on a linear motion stage.
• Integrating DCVO with a sliding-mode controller for performance analysis.

Main Results:

• The DCVO demonstrates complete insensitivity to accelerometer offset, unlike the SSVO.
• DCVO shows improved noise sensitivity formulation compared to SSVO.
• Experimental validation on a linear motion stage confirms DCVO's effectiveness.
• DCVO enables high-frequency switching for sliding-mode controllers, enhancing positioning accuracy.

Conclusions:

• The DCVO offers a robust and accurate solution for velocity estimation in motion control systems.
• Its insensitivity to accelerometer offset and improved noise handling make it superior to conventional observers.
• The DCVO significantly enhances the performance of sliding-mode controlled systems, leading to better positioning accuracy.