Research And Experiment On Motion Control Algorithm Of Self Moving Stacking Forklift Truck

Autonomous mobile stacking forklift as an important part of automated warehousing logistics.In order to realize autonomous movement control of forklift truck,the motion control algorithm of forklift truck platform and autonomous mobile stacking forklift truck is studied.An improved trajectory tracking,path tracking and point stabilization control algorithm for forklift platform and autonomous mobile stacking forklift is proposed.The accuracy of the algorithm is verified by simulation and experiment.The main contents and results are as follows:?1?The trajectory tracking control of forklift platform is studied.The kinematics model and error model of forklift platform are established,and a controller based on Lyapunov function and backstepping state feedback control algorithm is designed to control the steering angle and speed of forklift platform.The simulation and experimental results show that the proposed control algorithm can make the forklift platform converge to the desired trajectory.When the desired trajectory is stable,the control parameters?k₁,k₂,k₃,k₄?=?0.1,0.2,0.15,0.3?,linear tracking error is x_e=±7mm,y_e=±9.8mm,?_e=±4.2°.Degrees,arc trajectory tracking error is x_e=±6.2mm,y_e=±8.3mm,?_e=±5.8°,and good tracking accuracy is obtained.?2?The path tracking control of forklift platform is studied.The kinematics model is simplified to two degrees of freedom model.A path tracking control method based on heading angle error algorithm is adopted to control the steering and speed of forklift platform so that the forklift platform can move according to the expected path to achieve the goal of path tracking.The simulation results show that the path tracking control algorithm can make the robot converge to the desired path stably and quickly.The experimental results show that the horizontal error range of straight line path tracking is±8mm and circular arc path tracking lateral error range is±11 mm after the forklift platform tracking is stable,and good path tracking accuracy is obtained,which provides a reference for forklift platform path tracking control.?3?The point stabilization algorithm of forklift platform is studied.Based on the kinematics model of forklift platform,the differential equation of error in polar coordinates of forklift platform is established,and the improved point stabilization control rate of forklift platform is proposed.It is proved that the system is asymptotically stable when the constant parameter coefficient k_?>0,k_?>0,k_?<0,k_?-k_?>0.In addition,the third-order Bessel curve with variable parameters is used to fit the current point,the target point and the discrete point on the reverse extension line of the target attitude,which makes the path curvature of the platform smooth and smooth.The simulation results show that the point stabilization algorithm can make the forklift platform reach any position of the target in the global coordinates.The better path and point stabilization effect are obtained when the discrete point parameters of the Bezier curve are large.?4?The path tracking control problem of autonomous moving stacking forklift truck is studied.The automatic transformation of self-moving stacking forklift truck is carried out to realize automatic control.The model of autonomous moving stacking forklift is simplified as a two-degree-of-freedom model,and the path tracking algorithm based on the combination of heading angle error and pure tracking algorithm is adopted,which provides a theoretical basis for the steering and motion speed control of autonomous mobile stacking forklift truck.The experimental results show that the algorithm can make the self-moving stacking forklift achieve path tracking control.After tracking stability,the lateral tracking error is±20mm.It provides a reference for the path tracking control of autonomous mobile stacking forklift truck.In this paper,different research methods and technical means are adopted for forklift platform and autonomous mobile stacking forklift,and the accuracy of the algorithm is proved from three aspects:theoretical analysis,simulation and experiment.It provides theoretical basis and reference for the motion control and application of forklift platform and autonomous mobile stacking forklift.