Research on Compound PID Control Strategy Based on Input Feedforward and Dynamic Compensation Applied in Noncircular...

Area of Science:

• Manufacturing Engineering
• Control Systems Engineering
• Mechanical Engineering

Background:

• Fast tool servo (FTS) control is crucial for high-speed noncircular turning, demanding precision positioning and anti-interference capabilities.
• Traditional repetitive and speed feedforward control strategies for FTS show limitations under complex, real-world machining conditions like variable cutting forces and spindle speeds.

Purpose of the Study:

• To propose and implement an advanced compound proportional integral derivative (PID) control strategy for fast tool servo systems in noncircular turning.
• To address the shortcomings of existing methods in handling dynamic disturbances encountered in practical machining environments.

Main Methods:

• Development and implementation of a compound PID control strategy incorporating input feedforward and dynamic compensation.
• Testing the proposed control strategy under conditions simulating time-varying cutting forces, intermittent cutting, and fluctuating machine spindle speeds.

Main Results:

• The implemented compound PID control strategy demonstrated high responsiveness for micro-stroke motion in noncircular turning.
• The control strategy effectively mitigated disturbances arising from time-varying cutting forces, intermittent cutting, and spindle speed fluctuations.
• Machining tracking errors were consistently below ±2 µm, indicating high precision.

Conclusions:

• The proposed compound PID control strategy offers superior performance for fast tool servo systems in noncircular turning compared to conventional methods.
• This advanced control approach ensures excellent tracking performance and machining quality even under challenging and dynamic working conditions.