A robust variable sampling time BLDC motor control design based upon μ-synthesis

Area of Science:

• Control Systems Engineering
• Robotics
• Electrical Engineering

Background:

• Variable sampling rate systems are common in applications where speed information is derived from trajectory position marks.
• Conventional fixed or multi-rate sampling theories are insufficient for speed-dependent systems due to inherent uncertainties.
• These uncertainties arise from the variable sampling rate, impacting system dynamics.

Purpose of the Study:

• To derive a convenient expression for speed-dependent sampling rate systems.
• To translate the effects of varying sampling rates into multiplicative uncertainties.
• To design a robust performance controller for these systems.

Main Methods:

• Development of a mathematical expression for speed-dependent sampling rate systems.
• Modeling the varying sampling rate effect as multiplicative uncertainties.
• Application of μ-synthesis for robust controller design.

Main Results:

• A novel method to handle variable sampling rates in control systems.
• Successful translation of sampling rate variations into quantifiable system uncertainties.
• Demonstration of robust controller performance through implementation.

Conclusions:

• The derived expression and uncertainty translation effectively address challenges in speed-dependent sampling rate systems.
• The μ-synthesis approach provides a robust controller design for systems with variable sampling rates.
• The method's effectiveness is validated by its successful implementation on a Brushless DC (BLDC) motor.