Study On Identification Of Rigid Body Inertia Properties Based On Direct Parameter Identification

The engine is one of the main sources of automotive vibration.Reducing the vibration transmitted by the engine to the car body is an important measure to improve the NVH performance of the car.A properly designed suspension system is beneficial to reduce the transmission of vibration excitation from the engine to the car body,which thereby helps to solve the vibration and noise problems of the vehicle,improving the riding comfort of the vehicle,and extending the fatigue life of automobile parts.The optimal design of the engine mounting system and the simulation of the entire vehicle are inseparable from the inertia parameters of the engine,including mass,center of mass,rotational inertia and inertial product.Therefore,it is of great engineering practical significance to identify the inertial parameters of the engine accurately and efficiently.In order to identify the inertia parameters of the engine accurately and efficiently,studied the direct parameter identification method of inertial parameters,principle experimental devices and experiments in this paper.Firstly,derived the direct parameter identification algorithm for rigid body inertial parameters,and wrote the algorithm program of the inertial parameter identification.Introduce an example of multi-body dynamics simulation analysis to identify the inertial parameters of the body to be tested,verified the feasibility of the algorithm.Then,designed the principle experimental device,put the excitation point and the response point on the tray which reducing the experimental error.With the help of simulation analysis in multi-body dynamics software,verified the feasibility of the principle experimental device.On this basis,investigated the influence law of excitation point and response point coordinate error,excitation angle and angle error of the sensor installation,and system noise on the identification accuracy of inertial parameters.Finally,built the principle experimental devices of two support methods of curved rod spring and rubber respectively,and carried out experimental study on the identification of inertial parameters of standard block.Research indicates that the inertial parameter identification method in this paper can identify 10 inertial parameters of the rigid body at one time.By exploring the factors that influence the accuracy of inertial parameter identification,system noise and excitation angle error have the greatest influence on the identification accuracy of inertial parameters.In addition,coordinate error of excitation point and response point,sensor installation angle error have little effect on mass and center of mass position,and have greater influence on rotational inertia and inertia product.In the principle experiment of the curved rod spring suspension,the identification error of the inertial parameters of the body to be tested is within 14.59%,the mass and centroid position errors are within 8.4%,indicates that the recognition accuracy is high.In the principle experiment of rubber mounting,the identification error of the inertial parameters of the body to be tested is within 9.48%,and the identification error of the mass and centroid position is within 3.46%.The recognition accuracy is very high,which meets the actual engineering needs.