Abstract
KEYWORDS – road mapping, preview sensor, active suspension, ultrasonic sensors, sensor array
ABSTRACT – Active suspension system has been employed by the auto industry in order to improve ride-quality and handling. Only a little betterment, however, is obtained without road preview sensor in building active or semi-active suspension system. In these days, sensors such as stereo camera, laser, and ultrasonic sensor have been employed when previewing surface height of road for active or semi-active suspension system. However, there are disadvantages with camera and laser sensors as they are high in price and need complex algorithms. Thus, the parallel information processing devices are required to compute tangled calculation in real-time which adds more budgets. On the other hand, the ultrasonic sensor uses ToF (Time-of-Flight) method to measure the distance and the sensor is sensitive to ambient noise. Therefore, this makes hardware and software calibrations of sensor essential steps. More robust measurement on noise is possible by using ultrasonic sensor array which consist of multiple receivers and a transmitter. Furthermore, information gathered from the sensor array installed in a vehicle can differ by the moving speed of a vehicle. Therefore, ICP (Iterative Closest Point) logic is used for optimization. To test the proposed algorithms, experimental bench is produced and the height of road is intentionally designed to be continuously different. The result obtained from the cost-efficient MCU and ultrasonic sensor array is analyzed. The purpose of this study is to test a cost-efficient ultrasonic sensor array to mapping the road surface in real-time.