Asymmetric S-Curve Generation and Tracking Under Motion Constraints: An Experimental Validation

S-curve is one of the most applied approaches for trajectory generation for the point-to-point movement in industrial drives. In this note, the asymmetric S-curve structure is addressed to develop a single-axis motion structure, and an algorithm is introduced to generate the desired motion. Furthermore, a cascade P/PI position controller structure with a feed-forward path is suggested and the determination of the controller gains is discussed. Aiming to improve the smoothness of the desired trajectory and to reduce the tracking error, the proposed scheme containing both trajectory generation and controller structure is implemented experimentally in a ball screw linear motion system. The mechanical model parameters in that experimental setup, and accordingly the controller gains, are obtained based on an estimation algorithm. The acquired results show that the proposed controller structure with the asymmetric S-curve generation algorithm is convenient for practical applications.