Automobile six-degrees-of-freedom wheel center force test and vibration noise contribution rate calculation method

Abstract

The invention discloses an automobile six-degrees-of-freedom wheel center force test and vibration noise contribution rate calculation method. The method comprises the following steps: establishing a coordinate system; arranging measurement points and installing sensors; arranging excitation points and measuring the coordinates of the excitation points; measuring a frequency response function; solving a frequency response function matrix from the center of a wheel hub to a response point; solving a frequency response function vector from the center of the wheel hub to a target point; carrying out road test; solving an excitation power spectrum density matrix; verifying the identification effectiveness of the excitation power spectrum density matrix; and calculating the energy contribution rate of each degree of freedom to the response of the target point. Compared with the prior art, the method of the invention has the following advantages: (1) as the excitation force and excitation torque of the road to automobiles can be considered simultaneously, error caused due to neglect of excitation torque in the prior art is eliminated; and (2) as the energy contribution rate of the wheel center force at each of the six correlated degrees of freedom to the vibration noise of automobiles can be calculated, error caused by an ordinary coherence coefficient method or a multiple correlation coefficient method is avoided.

Description

technical field [0001] The invention belongs to the technical field of vehicle engineering, and relates to a vehicle testing technology, in particular to a vehicle six-degree-of-freedom wheel center force test and vehicle vibration and noise energy contribution rate which can be applied to the correlation and consider the excitation force and the excitation torque at the same time Calculation method. Background technique [0002] With the rapid development of my country's science and technology and the improvement of people's living standards since the reform and opening up, while the use of vehicles such as vehicles has become more and more popular, people have also raised concerns about the NVH (noise, vibration and harshness) performance of vehicles. higher and higher requirements. Identifying the excitation of the road to the vehicle and calculating the energy contribution rate of each degree of freedom excitation to the vehicle's vibration and noise is the premise for t...

AI Technical Summary

Problems solved by technology

At present, only the excitation force is considered in the test for the center excitation of the automobile hub, but the excitation torque is not considered. This will inevitably bring errors in the subsequent analysis, such as principal component analysis and multi-reference transfer path analysis.

The reason why the excitation torque is not considered is mainly because it is difficult to directly measure the torque-acceleration frequency response function through experimental methods

And because there is only a time difference between the front wheels and the rear wheels when the car runs straight, the suspension of the left wheel and the right wheel is symmetrical, and the smoothness of the road surface is basically the same, so there is a large correlation between the excitations of different degrees of freedom acting on different wheels. However, using the constant coherence coefficient method or the multiple coherence coefficient method to calculate the energy contribution rate of each degree of freedom excitation to the vehicle vibration and noise will introduce relatively large errors

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