Integrated Design And Development Of Marine Shock Absorber Performance Test System

Shock absorber test bench is a device for measuring performance parameters such as static stiffness,dynamic stiffness,and creep of rubber shock absorbers used in ships,which plays important roles in the design and selection of shock absorber.To overcome the weakness in the mechanical and electro-hydraulic test bench,an electric test bench based on modern servo control technology is developed.An electric cylinder is utilized to convert the rotary motion of the servo motor into linear motion.Meanwhile loading force is produced by squeezing the shock absorber with an electric piston rod.The specific research content is as follows:Firstly,the components and the main principle of the proposed test bench are presented.The complete mathematical model of the system is established.According to the mathematical model,the control strategy of the shock absorber test bench is proposed.In the static testing mode,a compound double-closed-loop control structure including a motor velocity controller and a loading force controller is constructed.In the dynamic testing mode,a composite control structure including a feedforward compensator and a double closed-loop feedback controller is designed.Then,based on the system mathematical model and control structure established above,a series of performance indexes such as control errors and motor power are established.The complicated interactions of design parameters are analyzed through numerical simulations.To minimize the control error and the motor power simultaneously,a multi-objective and multiconstrained optimization problem including both mechanical and control parameters is formulated.The optimization problem is solved by a simulated annealing algorithm to obtain the optimal parameters.Finally,the main components of the shock absorber test bench are selected according to the design results,and a test bench is established.The control program based on Twin CAT3 and the software based on Lab VIEW are developed.Experiments results verify the feasibility of the control structure.Meanwhile,the test bench has lower energy consumption and higher tracking performance,which demonstrates the effectiveness of the optimized design method.