车辆运行品质的智能手机检测方法及姿态误差矫正

因车体坐标系统和手机坐标系统存在角度偏差，为使手机检测数据真实反映车体振动加速度，提出针对手机姿态误差的系统性矫正方法. 该方法以重力方向为基准矫正手机垂向加速度，借助车体横、纵向加速度的正交性矫正手机水平向加速度，并基于极大似然估计原理评估角度偏差，保证手机姿态矫正的可靠性. 结合现场测试结果表明:两部智能手机检测数据经姿态误差矫正得到以重力方向为基准的垂向角度修正值分别为0.008° 和0.007°，两者水平夹角为29.75°，与试验放置夹角30.00° 偏差0.25°；智能手机与高精度传感器检测的车体加速度在时域和频域的幅值、主频均一致. 

Using Smartphone to Detect Vehicle Running Quality and Its Coordinate Alignment

As there is angle deviation between the car body coordinate system and smarphone coordinate system, a systematic correction method for the smartphone coordinate alignment is proposed to make smartphone sensor data truly reflect the vibration acceleration of the vehicle body. This method corrects the smartphone vertical acceleration according to gravity direction, and the smartphone horizontal acceleration by means of the orthogonality of the lateral and longitudinal acceleration of the vehicle body. The maximum likelihood principle is used in the estimation of angular deviation to ensure the reliability of smartphone angle correction. Field test results indicate that the detection data of two smartphones obtained a vertical angle deviation of 0.008° and 0.007° relative to gravity direction, the horizontal angle between both smartphones is 29.75°, and the deviation from the test placement angle 30.00° is 0.25°. The amplitude and main frequency of the vehicle body acceleration respectively detected by the smartphone and the high-precision sensor are consistent in time domain and frequency domain.