Shahrood University of Technology Journal of Solid and Fluid Mechanics 2251-9475 2 2 2013 05 18 Indirect type-2 fuzzy control of flexible-joint robots Indirect type-2 fuzzy control of flexible-joint robots 31 43 135 10.22044/jsfm.2013.135 FA Mohammad Mehdi Fateh Mahdi Aliyari Journal Article 2012 12 25 Since the properties of flexible-joint robots such as nonlinearity, being time variable, coupling and high order, an accurate modelling of its dynamics is complicate. Therefore, model-free control methods are a suitable choise to control flexible-joint robots. In this paper, an indirect type-2 fuzzy control is presented for flexible-joint robots. The proposed scheme has the advantage that is computationally simple ، decoupled and free from manipulator dynamics. This advantage is for adopting voltage control strategy instead of common torque control strategy. The proposed method includes two interior loops: the inner loop controls the motor position using indirect type-2 fuzzy control while the outer loop controls the joint angle of the robot. To do this, an adaptive proportional-integral-derivative (PID) controller is used and by defining proper sliding condition using gradient descent there PID control gains are updated. Stability analysis is presented to verify the effectiveness of the proposed method. A three-joint articulated flexible-joint robot is simulated and simulation results show the superior of the indirect adaptive type-2 fuzzy system to nonlinear control method. Since the properties of flexible-joint robots such as nonlinearity, being time variable, coupling and high order, an accurate modelling of its dynamics is complicate. Therefore, model-free control methods are a suitable choise to control flexible-joint robots. In this paper, an indirect type-2 fuzzy control is presented for flexible-joint robots. The proposed scheme has the advantage that is computationally simple ، decoupled and free from manipulator dynamics. This advantage is for adopting voltage control strategy instead of common torque control strategy. The proposed method includes two interior loops: the inner loop controls the motor position using indirect type-2 fuzzy control while the outer loop controls the joint angle of the robot. To do this, an adaptive proportional-integral-derivative (PID) controller is used and by defining proper sliding condition using gradient descent there PID control gains are updated. Stability analysis is presented to verify the effectiveness of the proposed method. A three-joint articulated flexible-joint robot is simulated and simulation results show the superior of the indirect adaptive type-2 fuzzy system to nonlinear control method. https://jsfm.shahroodut.ac.ir/article_135_e9df6f8577fcf6324962b3ad3a2b8f79.pdf