Research On The Flexible Robot System For The Underwater Inspection Of Ship Locks

Ship locks play important roles in inland river navigation,and the emergent and routinary maintenances guarantee the sustainable operation of ship locks with the fact that some ship locks are working under longtime overloaded condition due to the increasing of the freights.In the thesis,aiming at the inspection of ship locks underwater facilities,a flexible robotic system is developed through the determination of system scheme,structure design of the robot,underwater camera,integration and test verification,etc.Due to the facts of confined space and turbid water for underwater inspection for ship locks,a scheme combining a flexible robot,which can deal with combine space compliantly,and special underwater cameras is proposed.The pneumatic artificial muscle(PAM)is chosen as the actuator,and the structure scheme of the robot and on-site arrangement are determined.The joint structure based on “flexible actuation and flexible structure” is designed and its structural parameters are determined with the force behavior of the PAMs and underwater space.The coordinate systems of the flexible system are constructed and the Homogeneous transformation matrix between the end camera and the base coordinate systems of the robot.Comparing the matrix with desirable pose matrix,the joint variables and the layout position are obtained.The bending performance of the robot is testified though the no-load and load testing of joints,and the lab-test of the robot.A Cartesian coordinate robot and two pneumatic clamps are designed to realize the large range underwater movement of the flexible robot.According to the scheme of underwater camera,a close-range and a focus adjustable cameras are designed through work on LED lightening source,water tightness and underwater imaging test,for adapting to the underwater object inspection under different turbidity.A testing platform is constructed to perform the imaging test and light attenuation in turbid water and it shows that the green light attenuates slowest,then red light,and the fastest is blue light.A digital controller for LED lightening source is implemented and experiment proves its feasibility,which will be a basis for the special lightening source for cameras in turbid water.The hardware and software platform of the control system of the robot is implemented,and then integrated with robot structure to form the flexible robotic system for the underwater inspection of ship locks.Many on-site sluice gate and water gate tests were performed at the Yundong Ship lock and Mangdao Ship lock of Jiangsu Province,and it shows that the system can send cameras to the inspection spots with suitable pose through adapting to the underwater confined space compliantly,and acquire clear images of main tracks.The experiments testify the feasibility and practicality of the system.The system provides a new technical method for the underwater inspection for ship locks and obtain objective materials for underwater facilities while decreasing the workload of inspecting personnel.At the same time,it can also advance the research and application of flexible robots.