Research On Force Analysis And Motion Control Of Wall-climbing Robot For The Ship

Wall-climbing robot is mainly adopted in places which cannot be reached by humans and for the ship hull maintenance and inspections, rust removal, spray lacquer and so on, its main purpose was to replace artificial and improve the work efficiency. The robot's working process which requires both stability and flexibility, this paper revolves around the two major problems for research.Aiming at the static stability for the tracked wall-climbing robot,the characteristics of the robot and the force between the robot and wall were researched, in order to facilitate the force analysis,a new definition of load distribution coefficient of the track was proposed,the static model of linear motion and turning motion were established.The relationship between the magnetic adsorption force,wall inclination angle and the load distribution coefficient of the robot and the force between the robot and wall were simulated with Matlab software in the end.The results of simulation indicate that the requirements of adsorption force for single magnet mainly depends on the load distribution coefficient of the track and wall inclination angle,the magnet adsorption force has a great influence on the turning motion flexibility,the requirement of the motor torque mainly depend on magnetic adsorption force and wall inclination angle.Aiming at the dynamic modeling problem of climbing robot, we established the generalized coordinate of climbing robot system, then get the nonholonomic constraint dynamics equation, finally we calculated the dynamic model of the climbing robot by use of Lagrange dynamic equation of the second category and simulated dynamic model in the end. We introduce the mathematical model of DC motor, and simulated the linear motion and turning motion of the robot dynamic model with Matlab software, and then we get the motion trajectory of the robot on the wall. The simulation result indicates the correctness of the dynamic model by contrast with experiment result.Aiming at the motion control of climbing robot, we designed a trajectory tracking controller based on the difference of the climbing robot. First we decoupled the nonlinear dynamic model of the robot, then according to state feedback and expected trajectory, we calculation the motor output torque by the algorithm and realized the trajectory tracking control. The simulation results show that the trajectory tracking controller has a good performance for the robot dynamic system.On the basis of theoretical research, we designed a permanent magnetic adsorption caterpillar climbing robot prototype, and had an experiment test on robot desorption performance, motion flexibility and dynamic model.According the contrast experiment, the theoretical analysis result of motion force analysis and dynamic modeling ware verified by the experimental results, and increase the load distribution coefficient will promote the adsorption stability of the climbing robot under the premise of motion flexibility. The results provide a theoretical basis for climbing robot structure design and optimization and realization of automatic control.