PID-like Fuzzy Logic Control Scheme for Control of a Planar Parallel (3PPR U-base) Manipulator

The paper investigates the control of a three prismatic-prismatic-revolute (3 PPR) U-base planar parallel manipulator in the presence of parameter uncertainties and unknown disturbances. The 3PPR U-base planar parallel manipulator is a motion platform with singularity free workspace (bounded orientation angle θz ≤ ±90 ◦) and has manipulator legs located on the plane in association with a moving platform. Each leg has a prismatic-prismatic-revolute joint configuration in which one prismatic joint is active in each leg. To control the end-effector’s mobility of the 3PPR U-base motion platform a proportional-integral-derivative (PID)-like fuzzy logic control scheme is introduced. To demonstrate the effectiveness of the proposed controller, experiments (on a in-house fabricated prototype of the proposed manipulator) with a desired characteristic trajectory are performed and its control performance is compared with an existing conventional PID controller. The results confirmed that the proposed controller has the capability to track the desired task space trajectory and gives a better robust control performance.