Automatic road condition measuring system for intelligent small car based on accelerometer sensor

CHENG Bin-jie， WEI Feng-yuan， JIN Meng-jia
（College of Electrical Engineering， Zhejiang University， Hangzhou 310027， China）

Abstract： Aiming at the problem of measuring road condition automatically，an intelligent small car was designed to measure road's gradient. The accelerometer sensor ADXL345 was used to collect data of road's gradient automatically. The Bluetooth module was adopted to realize the communication between a small car and a personal computer. Thus controlling the car wirelessly and returning the data of road's gradient back to PC. Pulse width modulation（PWM）control was used to realize close-loop speed control and ensure the low speed of a small car. Matlab was used to make graphs of road's condition，which shown the variation of roads' altitude. Warning alarm would be set off if road's gradient was beyond a safe level. The results indicate that the measuring system can satisfy the requirements of data collecting，low-speed running，graphs making，safety warning and other functions referred to above.
Key words： accelerometer sensor； intelligent small car； automatic road condition measuring system； ADXL345