Stability Analysis And Active Anti-sway Research On Wind Loads Of Large Truss Bridge Inspection Vehicle

The large truss bridge inspection vehicle is used for detecting and repairing large-width bridges by sending the inspectors and equipment to the bottom of the bridge through the deployed beams.During the work,the long beams of the bridge inspection vehicle deploy to form a large-span suspended structure.The beams are vulnerable to vibration due to the external excitations such as telescopic movement,moving load,walking excitation,wind load,which reduces comfort and safety at work.In order to suppress the vibration of the beams and improve the safety and stability of the inspection vehicle,this paper takes a trussed bridge inspection vehicle as the research object,combining theoretical research and simulation analysis,the stability and active anti-sway system under wind load of a large truss bridge inspection beam system are studied in depth.Firstly,the movement equation and mechanical model of the beams system for telescopic movement,moving load and pedestrian excitation are established.And analysis the dynamic response of vehicle excitation vibration of inspection vehicle by ANSYS.The vibration response curve of the beam is obtained and the influence of the vertical displacement change on the safety is evaluated.Secondly,the basic characteristics of wind load and analytical method of structural wind vibration are studied.The Davenport wind spectrum and power pulsating wind time history curves are analyzed by using MATLAB.Based on the random vibration theory,the transient dynamics and spectrum analysis of the inspection beam are performed by ANSYS,wind-induced vibration displacement of beam is obtained.The influence of wind load on the inspection of the beam system is evaluated.The simulation results show that the vibration displacement is obviously larger than the limit value in the design specification,which will bring risk to the safety of the inspectors.Then,the active anti-sway scheme and control strategy are proposed for vibration characteristics.The mechanical structure,electro-hydraulic servo system and control system are used to suppress the vibration,selected the key components of the hydraulic system,and analyzed the hardware and control flow of the PLC control system.The stability of the system is analyzed by MATLAB,the results show that the electro-hydraulic servo system is stable.Finally,the fuzzy PID control method based on PLC is used to realize the on-line control of the system.The controller design is implemented using FUZZY toolbox of MATLAB.The system model is established in Simulink and the simulation analysis is performed.The result proves that the control system has better daptability and robustness.Through the coordinated simulation of ADAMS and MATLAB,the active anti-sway system is analyzed,and the rationality of the design scheme and the reliability of the control strategy are verified.