Research And Design Of Vehicle Attitude Measuring System Based On Multi-dimensional Acceleration Sensor

With the gradual improvement of the road network, the focus of our country’s road construction has gradually shifted from the construction of the new highway to the maintenance of the existing highway. Existing road detection vehicles of domestic and foreign usually detect road by the linear laser scanner, however, the road is often not smooth, and linear laser scanner is installed and fixed on the vehicle, in the driving process, vibration caused by road roughness and vehicle acceleration, deceleration and the engine vibration may cause the change of linear laser scanner’ attitude, resulting in reducing the scan precision. In the existing road detection vehicle, the vehicle attitude detection is realized by the combination of the inertial attitude measurement system, to make up the detection error caused by the change of attitude. However a combined inertial attitude measurement system is often expensive, and it usually focus on measurement of the whole vehicle attitude. Actually measurement error is caused only by the change of part of vehicle which equipped with laser scanner on, measurement of the whole vehicle attitude not only caused a redundant system, also leads to the lower accuracy of the attitude measurement of the part of vehicle which equipped with laser scanner on.For those problems, this paper designs a vehicle attitude measurement system based on multidimensional acceleration sensor, and targeted for the attitude change of part of vehicle which equipped with laser scanner on. According to the actual need, through the establishment of pavement and vehicle vibration model, the vibration acceleration of the body was analyzed, considering the road detection last long duration, integral algorithm based on half vehicle model of vibration was designed. The validity and superiority of the algorithm was proved by shaking table experiments and real road test, and finally the PCB design of the acceleration signal acquisition circuit was completed.The main research works of this paper mainly are as follows:Firstly, the time-domain model of road roughness was established based on the grade of highway roughness, analyzed the characteristics of part of vehicle which equipped with laser scanner on, and established four degrees of freedom 1/2 car transverse vibration model, and analyzed acceleration characteristics using MATLAB, which were important bases of the integral algorithm.Secondly, the existing integral algorithm was analyzed. According to road detection should last for long, based on the characteristics of four degrees of freedom 1/2 car transverse vibration model, integral algorithm was designed which can be carried out with high precision for a long time. And through analyzing attitude change of part of vehicle which equipped with laser scanner on, attitude representation method was designed.Then through the vibration test and road test, acceleration data of different frequency was integrated and integral error was analyzed, to verify the validity and superiority of the algorithm.Finally, according to the actual needs of road detection, based on ADS1278 chip, 8 channel acceleration signal acquisition circuit was designed to collect acceleration data from different sensor on the different direction parallelly, and the PCB design was completed.