Path Planning Using Fuzzy Logic Control of a 2-DOF Robotic Arm

In this paper we propose an algorithm for trajectory tracking of a 2-Degrees of Freedom (2-DOF) robotic arm, using fuzzy logic controllers for each joint. The idea came from the enormous benefits of the potential use of intelligent robots and robotic elements in the medical field, as this type of robotic arms can be used in heart surgeries and other procedures. The proposed fuzzy logic controller scheme uses three linguistic variables as inputs (position, velocity and acceleration). This differs from the commonly used robotic arm path tracking control techniques that usually use position and velocity as inputs. Firstly, a detailed specification and modeling of the 2-DOF robot arm is provided. For the control of each joint, we build a separate fuzzy logic controller. The inputs for the both fuzzy logic controllers are the same, but they differ in the proposed rule bases and the appropriate membership functions. The performance of the proposed control scheme is assessed by calculating the trajectory tracking error, using Root Mean Square Error, for three different types of input signals (sinusoidal, square waveform and free waveform). Because of the potential use of this type of control in robotic heart surgery manipulators, the analysis of the tracking performance of the periodic sinusoidal signal is especially emphasized. According to the obtained simulation results, it can be concluded that the algorithm shows an adequate performance in all testing scenarios. A complete simulation environment is developed through the MATLAB/Simulink software.