Design And Study Of Automatic Ultrasonic Testing Device Based On Five-Bar Mechanism

Mooring chains are important connection parts of aquatic working platforms. They must be reliable for the safety of working platform. In order to ensure that the mooring chains'reliability , the mooring chains must be ultrasonictested before taking into practice. Ultrasonic inspection of mooring chains is manually operated now. The manual ultrasonic inspection is hard intensity, and can not ensure all the surface inspected .In order to change the situation, this thesis put forward a new automatic inspecting procedure and testingdevice, made further researches into some key problems such as semi-circumference scanning five-bar mechanism. Following are the main contents of the research work,1. Design automatic ultrasonic inspection process of mooring chains , based on the analysis of structure features of mooring chains and themanual ultrasonic testing .Adopt five-bar mechanism as scanning mechanism.2. Kinematics and inverse kinematics of five-bar mechanism are analyzed based on second - class Assur groups . Equations of kinematics and inverse kinematics are obtained. Workspaces of three kind five - barmechanisms meet the driving requirements are analyzed.3. Optimization parameters of the semi-circumference scanning five-bar mechanism are induced , to minimize the acceleration fluctuation of the servo-motor based on inverse kinematics analysis. The performance of the semi-circumference scanning five-bar mechanism is excellent when used to scan the maximal and the minimal chains. 4. The motion transmission of semi-circumference scaning five-bar mechanism is analyzed by Jacobian coefficient. Error of position of probe caused by error of import parameter and error of structure is analyzed. KEYWORDS: mooring chain, automatic ultrasonic testing, five-bar mechanism, optimization, error analysis...