Research On Loading System Of Friction And Wear Test-bed For Connecting Rod Small End Bearing

With the diesel engine constantly pursues high strengthening technology,the connecting rod small end bearing has a bad working condition and high maintenance costs,it directly affects the performance of diesel engine.In the research and development stage of connecting rod small end bearing,it is necessary to carry out load impact test on the test bench,in order to explore the cause of bearing damage and the rule of bearing life,avoid bearing's premature wear,and improve the service life of diesel engine.Therefore,the loading system of friction and wear test-bed for connecting rod small end bearing was studied,which can pursue the real simulation of the connecting rod small end bearing's actual working condition.A reasonable controller was designed,the system's reliability and effectiveness were ensured through simulation analysis.Firstly,according to the performance requirements of the loading control system,the proposed scheme was compared and theirs relative merits were analyzed,the most appropriate loading scheme was designed.Then the mathematical model of the system was established,the stability of the system was analyzed,the mechanism and parameters of the system were optimized,the performance index of the system was checked to meet the requirements,and the improvement measures was put forward.Secondly,with the powerful simulation ability of Simulink,the mathematical models of PID control and fuzzy adaptive PID control of loading system were simulated.By analyzing the step response characteristics and the positive tracking curve at different frequencies of the system,the effect of the two controllers on the system is investigated.By comparing the improvement of simulation results,a better effect of the fuzzy adaptive PID controller was proved.In order to improve the accuracy of the simulation system,AMESim simulation was used to verify the loading system's mathematical model and the correction effect of the two controllers.The interface of co-simulation with Simulink was set up,and the co-simulation model was established.According to the simulation results of the positive tracking curve at different frequencies,the superiority of the fuzzy adaptive PID controller was further verified.Finally,fuzzy adaptive PID control was adopted,the connecting rod small end bearing's actual working conditions of different loads and frequencies were simulated under the co-simulation environment.By analyzing the tracking condition when the system outputs the maximum loading force and loading frequency,the loading system of the test-bed can simulate the change of engine cylinder pressure better,and the error was small.According to the maximum relative error,the feasibility and reliability of the loading system was verified.