Research On Local Path Planning And Trajectory Tracking Control Of Autonomous Cleaning Robot

The local path planning and trajectory tracking control of autonomous cleaning robots play an important role in the road cleaning between vehicles in parking lots.How to achieve safe and efficient cleaning in complex parking lot environments is the focus and difficulty of cleaning robot research.This paper takes the autonomous cleaning robot working in the area between the parking spaces as the research object,and studies the local path planning and trajectory tracking control of the autonomous cleaning robot to improve the trajectory tracking accuracy and cleaning efficiency.The main work of this article revolves around the following contents:1.Kinematic modeling and dynamic modeling of outdoor cleaning robot.Based on the four-wheel steering Ackermann geometry,establish the forward kinematics and inverse kinematics of the four-wheel independent drive and independent steering cleaning robot,complete the kinematic modeling of the cleaning robot,and choose the Lagrangian equation to establish the dynamic model of the cleaning robot,and simplified to a 7-DOF model.Finally,the model is verified experimentally by Adams simulation software.2.Research on optimization of local path planning algorithm based on dynamic window method.Aiming at the problems such as the unreasonable design mechanism of the DWA evaluation function and the robot’s tendency to fall into local optimality,an improved DWA algorithm was proposed.By improving the existing velocity evaluation function,the method adds the variation of angular velocity to the velocity evaluation function,and adds the evaluation function of the heading angle difference between the local path and the global path,which improves the local path planning of the cleaning robot in complex scenes such as unknown environment.ability.Finally,a simulation experiment was conducted based on the ROS platform to verify that the trajectory distance planned by the improved DWA algorithm was reduced by 6.6%,and the autonomous navigation efficiency was increased by 10.2%.3.Research on trajectory tracking control algorithm based on model predictive control.Based on the monorail kinematics model of the cleaning robot,a trajectory tracking controller based on MPC is designed,and the state space model of the car is established,and the prediction equation is derived through the state space model,and the corresponding objective function and constraint conditions are designed.Based on ROS,a car trajectory tracking control simulation experiment was carried out to track elliptical and "8"shaped trajectories respectively.The experimental results showed that the designed MPC controller can quickly and accurately track the desired trajectory.The position error and heading angle error of trajectory tracking are respectively below 20cm and within 20 degrees.4.System experiment and analysis.Based on the cleaning robot independently developed by the laboratory,a local path planner based on DWA and a trajectory tracking controller based on MPC are realized respectively.Carried out dynamic obstacle avoidance experiments in the corridor environment of the scientific research building and the parking lot environment,successfully predicted its future trajectory and completed the avoidance action.In the parking lot environment,the full-coverage reference path is generated according to the environment map,and the bow-shaped trajectory tracking control experiment and the cleaning mode optimization experiment are completed.The experimental results show that the cleaning robot can successfully complete the cleaning of the parking spaces,the trajectory tracking position accuracy is 25cm,and the heading angle accuracy is 20 degrees.The cleaning experiment meets the trajectory tracking accuracy requirements.The results of this paper have important practical application value for the cleaning application of autonomous cleaning robots in narrow working environments.