Stype acceleration and deceleration controlmethod based on Sigmoidfunction
                                            FANG Jiawei1, CAI Jinda2, YAO Ying2, ZHANG Dawei3

（1.School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;2.School of Printing Science And Artistic Design, University of Shanghai for Science and Technology,Shanghai 200093,China; 3.Optical instruments and systems engineering research center of the
Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093,China）

Abstract: Aiming at the motion stability for mechanical equipment, an Sshape acceleration and deceleration control method based on Sigmoidfunction was proposed to reduce the jitter and jitter time, during the start and stop of mechanical equipment. The feasibility of the control method was demonstrated from the aspect of displacement, velocity, acceleration jerk, etc. The timeplanning method of nonisochronous discretization was used to optimize and improve the timedivision of acceleration and deceleration. Program was designed by using time and speed array traversal and query. The experiment was carried out by the gantrytype spotting device based on ARM9 microcontroller, and the laser tracker was used for measurement. The results indicate that compared with unit step signal controlling method, the Sshape acceleration and deceleration controlling method based on Sigmoid function can reduce the jitter during the startstop phase of the equipment by 62.5%. Compared with 7section acceleration and deceleration controlling method, the Sshape acceleration and deceleration controlling method based on Sigmoidfunction can reduce the jitter time during the startstop phase of the equipment by 33.3%.

Key words: Sigmoidfunction; Sshape acceleration and deceleration; time planning method; ARM9; gantrytype spotting device