Development And Research Of Outdoor Led Display Cleaning Device

With the rapid development of China’s urban modernization,the outdoor LED display advertising industry has developed rapidly with the Internet technology.Due to the high distribution position of most outdoor display screens,the cleaning of outdoor display screens relies on manual operation.Based on the current insufficient development of cleaning equipment in the field,it is necessary to develop an outdoor LED display cleaning device with quick turnover,high automation and reliable cleaning operation.Firstly,on the basis of fully understanding the development status at home and abroad of this field and the distribution location of operating objects,the overall design scheme of the vehicle-mounted cleaning device was determined.Completed the detailed design of each assembly mechanism of the vehicular cleaning device by UG,and finished the virtual assembly,interference check,height check and space check.On the basis of related theories of robotics,established the mathematical models of each connecting rod of the lifting arm mechanism with the D-H modeling method,and derived the forward kinematic equations.The relationship between the length of each arm hydraulic cylinder and joint angle was obtained through MATLAB simulation;The inverse kinematics analysis adopts the geometric method to deduce the mathematical relation between the joint angle and the length of each arm hydraulic cylinder.The simulation results were extracted and the correctness of the inverse kinematics solution was verified by comparing the forward kinematics results.The virtual prototype of the cleaning device was established by using ADAMS,and the kinetics of the preparation and working conditions were analyzed respectively.Based on the simulation of the preparation condition,the cleaning rack,the driving hydraulic cylinders and the driving joint motion parameters were obtained,and the final hydraulic cylinder models were determined,verify that the working height of the cleaning device meets the requirements of the design scheme;The real-time change data of the mechanism and the connecting parts under each working position were obtained through the simulation of working conditions,which verified that the overall design of the cleaning device was reasonable and reliable and the working space met the design requirements.Based on the kinematics theory,the open-loop transfer function of the lifting arm control system was derived and established,and the Bode diagram of the hydraulic cylinder control system of each arm was obtained through simulation to verify that the control system was stable and controllable.On the basis of the control theory,the self-tuning PID control system of each arm was built through Simulink to verify that the intervention response of the control system was more rapid and reasonable.Based on the theory of joint space interpolation control,the dynamic equation of directional motion of manipulator is derived,and the relationship between the joint angles and interpolation time was obtained from the position of the target point.With the help of ADAMS and MATLAB/Simulink,built the joint simulation control system model of directional motion,and the theoretical and practical angle and position curves were obtained by adjusting PID control parameters to verify the feasibility and reliability of the control system.Analyzed the influence of external excitation on the work of manipulator,on the basis of finite element method and modal analysis theory,the finite element model of modal analysis was built through Hyper Works software,and the frequencies and amplitudes of each mode were calculated by Opti Struct.By comparing external excitation frequencies,it was verified that resonance would not occur in the mechanism and the structure design was reasonable.