Three-link planar robotic arm trajectory planning and its adaptive fuzzy logic control

The objective of this research work is to control the end effector of a three-link planar robotic arm to track any set of straight lines, given in the horizontal plane. The controller must be able to handle the above task even though the given set of straight lines and the corresponding specified velocities are unforeseen. In the area of trajectory planning, the redundancy problem in our robotic system has been solved by using the magnitude of the difference between two consecutive states of the joint angle vector. After that, we have combined the principle of fuzzy logic and our adaptive scheme to control the three-link robotic system. To investigate the resulting performance in tracking ability and control, we have designed and implemented the control board, motor driver, and real-time control software. These were used to perform some experiments on the real robotic system. The results of the experiments show that the proposed adaptive fuzzy logic based scheme can force the system to obtain the desired tracking control of the end effector. This control objective has been accomplished even though the system is subjected to significant variations of system parameters, as well as loading variations including the effects of nonlinearity.