Research On Robot With Suction Cup Adsorption Of Cable Surface Defect Detection And Maintenance For Cable-Stayed Bridge

Cable-stayed bridge is widely used in modern road traffic,especially in large-span occasions such as river-crossing and sea-crossing,because of its large span,economical cost,and beautiful appearance.The cable is an important part and the main stress component of the cable-stayed bridge.Once the cable is damaged,it will affect the safety of the whole bridge.Therefore,it is necessary to regularly check the condition of the cable and maintain it in time.Due to the disadvantages of low efficiency,high cost and poor safety,the manual detection method is gradually replaced by the cable detection and maintenance robot.According to the actual needs of cable surface defect detection and maintenance,this paper studies the cable detection and maintenance robot,and develops the climbing device,detection device and maintenance device.The specific work contents are as follows:1.According to the actual needs of cable inspection and maintenance,the overall design index is determined.The overall structure of the robot is designed,including cable climbing device,detection device and maintenance device.The climbing device is a trilateral structure,which is composed of three identical climbing units.The walking mechanism with wheeled suction cup is used as the moving method of the crawling unit,and the passive suction cup is adsorbed on the surface of the cable.The retractable characteristics of scroll spring are used to provide preload for the crawling unit.Four CCD cameras is used to collect images by the detection device,transmit them through wireless image transmission equipment,and carry out defect detection and processing on the computer.The maintenance device is composed of rotating platform,grinding module and painting module,which is used for the early repair of defects.2.The dynamic analysis of the climbing device under three different working conditions of static,upward and downward is carried out,and the critical driving condition is obtained.Through numerical calculation,the preload and suction cup adsorption force of the device are carried out.The simplified model of the climbing device is established in ADAMS software to simulate the crawling ability,crawling stability and load capacity.ANSYS software is used to simulate the stress concentration phenomenon and the deformation of the suction cup.The simulation results show that the climbing device can crawl stably under the common cable inclination angle,and has a certain load capacity;When the suction cup is adsorbed,the stress and deformation are mainly concentrated at the root of the suction cup,which has no effect on the inner cavity of the suction cup.The suction cup can be stably adsorbed on the surface of the cable.3.The control system of the robot is designed,which is composed of communication system,motor system and surface defect detection system.The system is divided into two parts: upper computer and lower computer.The hardware part of the lower computer adopts STM32 single chip microcomputer,and the software part is based on Keil uvision5;The upper computer interface is developed based on Py Qt5 framework.The communication system realizes the data transmission function between the upper computer and the lower computer;The motor system can change the working state of the motor on the robot according to the needs;The defect detection system is based on YOLOX network,which is used to train the defect data set of cable surface image,and the experiment is carried out on the test set.The results indicate that its m AP is 92.77%and FPS is 18,which has excellent detection efficiency and accuracy.4.The prototype of the robot is developed.Under the laboratory conditions,the PVC pipe is used to simulate the actual cable to carry out the robot test.The crawling capacity and stability tests of the climbing device are carried out under different inclination angles,and the load capacity test is carried out by adding a load of 3～15kg.Three kinds of common cable surface defects such as damage,gap and hole are made on PVC pipe,and the defect detection system is used for detection test.For the detected defects,repair test shall be carried out with maintenance device.The comprehensive test results show that the robot can crawl steadily along the cable with the detection and maintenance device,accurately identify the defects on the cable surface,and effectively repair the defects.The robot with suction cup absorption of cable surface defect detection and maintenance for cable-stayed bridge designed in this paper has the advantages of stable crawling,high detection efficiency,high precision and good real-time performance,and can realize the targeted repair of defects.Using the robot to regularly detect and maintain the cable surface in time can effectively ensure the safety of cable-stayed bridge,reduce labor cost and have high practicability.