Research On Path Planning And Control Of Low-speed Unmanned Vehicles In Specific Environment

With the improvement of the degree of scene automation and the development of driverless technology,the airport is becoming a “smart airport”.Thus,applying the driverless platforms at airports has become a trend.This paper designs a path planning and trajectory tracking control system for the unmanned luggage transportation vehicle in the airport,aiming to realize the function of safe autonomous driving.Firstly,according to the background of the subject,the design of hardware control system of unmanned transportation luggage vehicles was completed by using LIDAR,camera,GPS and IMU as the main sensors.The global coordinate system,the vehicle body coordinate system and LIDAR coordinate system are introduced and the kinematics model of the unmanned luggage transportation vehicle is established according to the chassis characteristics.Secondly,the principle of Lidar's environmental perception is introduced,which is used to measure the position and orientation of obstacles.Combining global waypoints and cubic B-spline curve,a smooth global path is generated.Simulations have verified that the smoothed global path is more suitable for unmanned vehicles to trajectory tracking.An obstacle avoidance method combining obstacle expansion and B-spline curve is proposed,and a local path planner is designed.The simulations show that the local path generated by this method can be well integrated with the global path,which ensures the safety and stability of unmanned vehicle.Thirdly,this paper designed integral separation PID controller and pure pursuit controller,and they are used to realize the trajectory tracking control of an unmanned vehicle.Simulation experiments were performed on several basic road conditions.The characteristics and the applicable road conditions of the two algorithms are compared through the results of simulation experiments.Considering the characteristics of the airport environment,the pure pursuit algorithm is selected as the trajectory tracking controller of the unmanned luggage transportation vehicle in this project.Finally,the system simulation experiment and analysis were completed.The unmanned luggage transportation vehicle can drive autonomously in the simulated airport environment through combining the path planning and trajectory tracking control.The experimental results confirmed that the algorithms applied in this paper were effective and feasible.