Research On Underwater Robot Control System For Bridge Pier Disease Detection

In 2021,heavy rains in Zhengzhou in Henan,Akhand in India,and the bursting of the Ahel River in Germany are just a microcosm of global precipitation.The impact was not limited to the time,but also caused hidden dangers such as bridges in the areas affected by the disaster.With the increase of service time,various diseases will appear,serious can lead to engineering accidents,and even casualties.In view of the current inadequacy of frogman detection methods and the rapid development of underwater robot high-tech,this paper designs an underwater robot for bridge pier disease detection,and studies its control system and control scheme.In view of the mechanical structure of the robot to meet the requirements of the detection task,considering that the robot is seriously affected by turbulence near the bridge pier during the floating period.In this paper,the dynamic structure of eight thrusters with symmetrical structure is designed to distribute the body in a vector to realize the omnidirectional motion of the robot in the floating state.Considering that the cover of moss and other moss plants on the surface of the pier adds natural lubricant to the surface of the pier,making it difficult for the robot to adsorb,the rope-driven arm clamping mechanism is designed to provide a reliable platform for the robot to detect stably.In view of the problem that the detection operation requires high precision and detection range,the overall control system adopts the control mode of the upper computer plus the underwater robot body structure.It is mainly divided into control unit,power supply unit,drive execution unit,bridge pier disease and robot attitude acquisition unit.The robot monitors the underwater detection image and the parameter interface of each sensor in real time through the host computer,so as to replace the diver to work underwater for a long time.In view of the problem that turbulence is prone to occur near the bridge pier and the attitude of small underwater vehicles is difficult to control due to environmental disturbance,this paper proposes a joint ROV attitude control algorithm based on TDfuzzy PID-IKF and IADRC.Firstly,the tracking differentiator is added to smooth the input signal,and the fuzzy PID controller output is fused with the Kalman filter estimation data to correct the sensor measurement value to realize the accurate estimation of the current attitude of the underwater robot.Secondly,the ADRC algorithm is improved by designing the nonlinear function of the low error linear odd function and the high error index function to compensate for the systematic error exceeding the threshold of the fuzzy rule.Finally,a switching strategy with fuzzy rule boundaries as the threshold is designed to realize the precise control of the low-error TD-fuzzy PID-IKF algorithm and the fast response of the high-error IADRC algorithm.The underwater robot for detecting bridge pier diseases developed in this paper has been successfully developed as a prototype.The designed robot carrying structure,control system,attitude control algorithm and related protection strategies were repeatedly tested in the river,and the relevant performance tests were completed,and the application effect of bridge pier disease detection was obtained.This work will play a valuable role in the safety inspection of wading bridges in the future.