A flexible velocity planning algorithm for high-speed mounter with both efficiency and precision

The excellent performance of semiconductor products is guaranteed by high-precision surface mount technology (SMT). In the process of chip mounting, the high speed and high precision are two important performance indicators. However, the high-speed and high-acceleration motion can easily lead to the mechanical residual vibration, which increases the adjustment time and even reduces the chip mounting precision. Thus, high speed and high precision are contradictory and difficult to realize at the same time. In the premise of ensuring the accuracy, a novel real-time motion control method based on the S-shaped velocity planning with optimal efficiency is proposed, which avoids the increase in the adjustment time of the ending point overshoot while improving the operating velocity of point-to-point. Firstly, the velocity feasible regions are determined under the kinematical constraints of the linear motor. Secondly, the acceleration or deceleration time series of the S-shaped velocity curve are calculated based on the constrains of boundary velocities. And then the time distribution of S-shaped velocity curve is updated with the goal of optimal efficiency under the small displacement constraints from point to point. Finally, the point-to-point real-time motion control is realized based on the S-shaped velocity planning algorithm. The correctness and effectiveness of the proposed method for chip mounting efficiency and precision are verified by simulation and experiment. And the experimental results show that the motion planning algorithm based on the S-shaped velocity planning can control the running velocity accurately in real time and improve the motion efficiency while ensuring the precision and stability.