Research On Path Tracking Control System Of Four Track Slipform Pavers

The transportation construction is an important foundation for economic development,and it will continuously play an important role in the implementation of the major national strategies.With the increasing load of vehicles,driving speed,and pursuit of safety,how to improve the quality of road construction has become a problem that we have to face.Cement concrete pavement has the advantages of high strength,long life and convenient of maintenance,etc.Therefore,it is suitable for rural road construction.As the main equipment of cement concrete pavement construction,slipform pavers follows the line by relying on the steering mechanism to properly steer to adjust the deviation between the distance sensor on the side of the pavers and the reference line.At the bend,it is necessary to manually switch the driving mode to steer.A lot of experience is required for the operator in whole proces,and the correction method of proportional control directly based on the deviation makes the pavers easy to turn too fast and excessive correction,results in low tracking accuracy.Firstly,this article analyzes the basic principles of paver path tracking and the working principle of the actuator.By improving the way of baseline layout and deviation getting of the traditional path tracking scheme,a new autonomous path tracking scheme of slipform pavers based on electronic positioning technology(such as global navigation satellite system)is proposed,and the steering control target of slipform pavers is analyzed.According to the steering target,the kinematics and dynamics of slipform pavers are analyed.Based on prediction model of the kinematic state space equation,the objective function and constraint conditions are established,and the MPC controller for the path tracking control of slipform pavers is built.The paper also puts forward an automatic placement method of slipform pavers,that the pavers can move to the starting point automatically and smoothly after entering the construction site.Finally,the simulation model of MPC controller is built in Matlab/Simulink using the virtual prototype model as the simulation prototype.The simulation test of the path tracking ability under the straight line trajectory,the arc trajectory and the trajectory of connecting a straight line and an arc is completed,and the simulation test of the rectification ability under the straight line trajectory and the arc trajectory is completed.Simulation experiments show that under the control of MPC controller,four track slipform pavers can follow various expected paths,and deviations can be quickly corrected without overshoot.On the one hand,autonomous and unmanned path tracking in the construction process is theoretically achieved.On the other hand,the accuracy of following the line is improved.In whole control process,the velocity and angular velocity,acceleration and angular acceleration always keep within the specified range.The control process is stable and no jump.