Rotary Flexible Joint Research Articles

Sliding mode control experiments of uncertain dynamical systems with time delay

This article presents the simulation and experimental studies for the nonlinear time-delayed dynamical systems with uncertainties. A rotary flexible joint made by Quanser is chosen as the model system to investigate the method for sliding mode control design. We considered the geometric nonlinearity of the flexible joint consisting of two linear springs. The system is assumed to have constant delay time and uncertain parameters with known upper and lower bounds. We also design an optimal sliding surface for the sliding mode control. Simulations and experiments are carried out to demonstrate the utility of the control method. Finally, the results from the simulations and experiments are in excellent agreement.

Implementation of a Fuzzy TSK Controller for a Flexible Joint Robot

This paper proposes a fuzzy TSK controller to control a rotary flexible joint manipulator. The flexibility of joint is performed by means of a solenoid nonlinear spring, which is connected between actuator output and joint input in a bilateral connection form to transfer the produced torque; also the smooth model of frictions is used for modeling the dynamics of flexible manipulator. The effect of coulomb friction and also gearbox backlashes is decreased by a pulsation signal as an extra voltage that is added to the control voltage of actuator. Actuator dynamics is modeled by consideration of saturation mode of armature current. Experimental results demonstrate that the proposed controller has an ability to control flexible joint manipulator with a good performance.

Computer Aided Strategies for Tuning GPC Controllers: A Case Study

Generalized predictive control, in its linear and analytical version, is a general-purpose technique that has been successfully applied to various classes of plants. However, when we move from stable and well-damped plants to plants with more complex dynamics (unstable, oscillatory), choosing the appropriate GPC parameters may become difficult. This paper introduces a case study which involves a rotary flexible joint, i.e. a system with an integrator and a stable lightly-damped mode, and shows that is indeed possible to tune quickly and effectively a GPC controller. This goal is achieved through a methodology based on the use of the usual sensitivity functions as closed-loop performance indicators, on a simplified choice of the observer polynomial and on plant-oriented design guidelines. The proposed methodology finds an adequate support in SIMART, a CACSD package for advanced control.