An Acceleration-sensor-based Trajectory Detection System Of A Moving Object

Trajectory detection in walking distance estimation, navigation system, human-computer interaction, and other fields have a wide range of applications, broad market demand put forward higher requirements on the cost and accuracy of the trajectory detection system. Traditional system solutions commonly used method of external observation, although the accuracy is higher, but the equipments are more complex and cost higher, there are some limitations. And the trajectory detection system based on MEMS acceleration sensor has characters of small size, easy to carry, and low cost to meet the large-scale residential and commercial needs.The principle of the trajectory detecting is displacement can be obtained after double integrals of acceleration. In this paper, three-axis acceleration sensor ADXL345is used to measure acceleration. Added to the system for sensing changes in the direction of movement, three-axis gyroscope L3G4200D detects angular velocity and quaternion method is used to calculate the angular velocity to get the rotation matrix which indicates a change in the direction. In order to reduce the error, the system uses the Kalman filter to filter out random noise, and proposes an adaptive compensation algorithm to compensate the accumulated error after integration.Hardware system uses microcontroller STC12C5A60S2as the main chip, which transmits the acceleration and angular velocity through the serial port to the host computer. All system algorithms are implemented in the MATLAB environment in the PC. The final experimental results show that the system can improve the accuracy of detection of the trajectory, but it needs further efforts to achieve the extent of practical application.