Robust Adaptive Control of Fully Constrained Cable-Driven Serial Manipulator with Multi-Segment Cables Using Cable...

Area of Science:

• Robotics
• Control Systems Engineering
• Mechanical Engineering

Background:

• Cable-driven serial manipulators (CDSMs) exhibit greater structural complexity than cable-driven parallel manipulators (CDPMs).
• This complexity leads to challenges in stable trajectory-tracking control due to higher model complexity and uncertainties.

Purpose of the Study:

• To propose a robust adaptive controller for n-degree-of-freedom (DOF) CDSMs actuated by m cables.
• To address challenges in stable trajectory tracking for CDSMs.
• To enhance control performance despite structural and parametric uncertainties.

Main Methods:

• Design of two high-level controllers for joint trajectory tracking (scenarios with known and unknown uncertainty bounds).
• Inclusion of an adaptive feedforward term based on inverse dynamics and a robust control term for uncertainty compensation.
• Development of a low-level controller for cable tension trajectory tracking.
• Stability analysis using the Lyapunov method.

Main Results:

• The proposed controllers demonstrate independence from uncertainty upper bounds and incorporate viscous friction coefficients.
• Experimental validation on a three-DOF six-cable CDSM confirms the controllers' validity and effectiveness.
• Comparative experiments show superior performance over classical proportional-integral-derivative (PID) controllers.

Conclusions:

• The robust adaptive controller effectively manages uncertainties in CDSMs, enabling stable trajectory tracking.
• The controller offers improved performance and robustness compared to PID controllers for CDSM applications.
• This work advances control strategies for complex robotic systems like CDSMs.