嵌入式汽车动态性能测试系统的设计

Design of embedded automobile dynamic testing system

为改善汽车的操作稳定性、平顺性和制动性以及为后续的底盘调校提供理论依据,设计了一套以惯性导航技术为基础、能实时采集汽车动态参数并绘制出动态参数图像的车载式测试系统。系统中组合微惯性传感器将采集的x、y、z三轴线加速度和三轴角速度的数字信号通过蓝牙模块传输到嵌入式设备,由编译的嵌入式软件对角速度和加速度进行姿态解算、积分处理;然后保存三轴线加速度、三轴角速度、三轴角度数据;并在嵌入式设备上绘制出汽车动态性能曲线图。蛇形道路试验结果显示,本测试系统测量出车辆行驶速度为17.5 km/h,横摆角速度在-25°/s^25°/s之间波动,侧倾角在-2.0°~2.5°之间波动。对比现行测试系统试验结果,本测试系统的侧倾角均方根误差为0.068 3°,横摆角速度均方根误差为1.294 0°/s,充分说明本测试系统所测量的的姿态角、角速度、速度是稳定可靠的,同时其操作过程简单、便于携带、集成度高,因此本系统具有较好的应用前景。

To improve operational stability,riding comfort and braking performance of automobile, and to provide the theoretical basis for the follow-up of the chassis adjustment, a set of real-time vehicular test system, which can acquire vehicle dynamic parameters and draw out the dynamic image,is designed based on the inertial navigation technology. In the system,the digital signals of acceleration along the x ,y ,z axis and the three axis angular velocity acquired by the combined micro inertial sensor are transmit to the embedded device through blue-tooth module, and the attitude calculation and the integral processing of angular velocity and acceleration are solved by the embedded software. Then,the data of three axis acceleration,three-axis angular velocity and axial angle are saved and used to draw the dynamic performance curve of the car on the embedded equipment. The serpentine road test show that the speed of the vehicle measured by the system is 17. 5 km/h,the yaw rate is between 25° /s -2 5° /s and the angle of inclination is between -2. 0 and 2. 5 degrees. Contrasting to test results of the current testing system,root mean square errors of the roll angle and the yawing angular are 0. 068 3° and 1. 294 0°/s , respectively, which fully showed that the results of the attitude angle and the speed values measuring by the test system are stable and reliable. This kind of automobile dynamic performance parameter testing system has a better application prospect owing to its characteristics, such as simple operation, easy to carry, high integration.