Optimal sliding mode control for cutting tasks of quick-return mechanisms

Area of Science:

• Robotics and Mechanical Engineering
• Control Systems Theory

Background:

• Quick-return mechanisms often face challenges in maintaining constant cutting velocity, leading to inaccuracies.
• Existing control methods may not adequately address the dynamic complexities of these mechanisms.

Purpose of the Study:

• To solve the constant cutting velocity problem in quick-return mechanisms.
• To enhance cutting accuracy and uniformity using advanced control techniques.

Main Methods:

• Optimal sliding mode control in task space for slider-dynamics.
• Design of a switching hyperplane to minimize position error over an infinite horizon.
• Implementation of a Jacobian compensator for mechanical advantage and controllability.
• Velocity profile construction based on mechanism and workpiece geometry.
• Verification of closed-loop dynamics stability using Lyapunov stability theory.

Main Results:

• Achieved uniform and accurate cuts throughout the workpiece.
• Demonstrated effective exploitation of mechanical advantage and ensured controllability.
• Validated the proposed control strategy through experimental results on a prototype.

Conclusions:

• The proposed optimal sliding mode control effectively addresses the constant cutting velocity problem in quick-return mechanisms.
• The method ensures precision and uniformity in machining operations.
• Experimental validation confirms the practical applicability and effectiveness of the control approach.