Slider movement planning based on improved S-curve acceleration algorithms for servo presses

Abstract. Servo press is a forming equipment that uses a servo motor to drive a crank slider for stamping and deep drawing process. The servo drive can adjust the motor speed in real time and dynamically, which provides an important support for the dynamic adjustment of the crank slider movement. To realize the smooth reciprocating movement of the large-mass and high-inertia slider, it is necessary to develop a motor speed adjustment algorithm to achieve a good match between the movement load of the slider and the torque that the motor can bear, to ensure the operation safety of the whole machine. S-curve algorithms are often used for the planning of slider movement curves, which is easy to produce flexible impact on the motor. Therefore, to improve this situation, an improved S-curve algorithm is proposed based on the above common methods, which realizes the motion control method of smooth speed change. In this paper, a movement planning algorithm for servo press slider with improved S-curve is proposed based on the 7-phase S-curve acceleration algorithm. Firstly, the kinematic calculation of the crank slider mechanism is carried out. Secondly, 4 control points are set up to divide the slider movement curve of the typical drawing process, including the idle feed stage, deep drawing stage, idle return stage, and loading/unloading stage. Furthermore, the uniform acceleration stage and the uniform deceleration stage are removed, and the acceleration cusp was smoothed, and the improved S-curve algorithm was obtained. Finally, the large-scale crank slider servo press and its deep drawing parameters in a literature are taken as an example to solve the slider movement curves by using the improved S-curve. The results show that the improved S-curve algorithm can be used for servo press slide motion profile planning, which can realize efficient deep drawing process mode.