Abstract: As the horizontal motion system of Bridge Crane is a nonlinear, variable parameter and strong coupling system, the nonlinear PID controller is used for positioning and anti-swing. The simulation results show that the proposed scheme has better dynamic and static characteristics and strong robustness. Keywords: nonlinear PID; anti-swing; robustness 1 Introduction The methods to eliminate crane sway are mostly based on the operating experience of crane operators. This method not only has a high labor intensity for operators, but also has poor precision and low efficiency in manual control, which is far from meeting the needs of modern production and transportation [1]. Therefore, the research on electronic anti-swing technology has received more and more attention from researchers. Because crane systems are complex, positioning control and swing angle control are interdependent, and the rope length and load mass change during operation, affecting swing angle and precise positioning control. Traditional PID control struggles to meet the required accuracy; while some optimal controls are designed based on linearized models, their actual control performance is not ideal. This paper proposes a control scheme based on nonlinear PID. Simulation results show that this control scheme can eliminate steady-state error, shorten system response time, and has strong anti-interference capabilities. For details, please click: Crane Anti-Swing Positioning Control Based on Nonlinear PID