Angle Measuring System Based On MEMS Accelerometer And Gyroscope

Nowadays, the continuous development of micro electro mechanical system has led to the related application of components such as accelerometer, gyroscope and so on, which makes the fact that more and more scholars are devoted to the concerned research. Many applications, such as inertial measurement system of space vehicle, equipment installation and construction, roads, ports and other engineering machinery field, all require angle measurement. Although the measuring accuracy of angle sensor is higher, but its price is more expensive, relatively speaking, the micro accelerometer and gyroscope have the characteristics of lower-cost, small volume, high stability and reliability, so using micro accelerometer and gyroscope to form angle measurement system has certain advantages. Most studies build angle measurement only using micro accelerometer, but because the accelerometer would be affected by motion acceleration in the process of high speed movement, an error would occur in the measurement of angle. On the other hand, if only gyroscope is used, although in high speed motion, measuring accuracy of the gyroscope is higher, but the angle is calculated by the integral of the angular velocity measured by gyroscope, in the process, error will be caused because of the drift error of gyroscope. Hence, it is necessary to fusion the signals of accelerometer and gyroscope to obtain the tilt angle.First of all, this study analyzed and compared the accuracy of the complementary filter, the gradient descent method and the kalman filter from the aspects of the value of the mean, standard deviation and range, and complementary filter was finally determined because of its highest accuracy, which was applied to the fusion of gyroscope signals and accelerometer signals. In the end, a low cost and high-precision angle detection system was put forward, using ADuC7020 micro controller that was responsible for handling the signals measured by the inertial sensors, which is one of the most important part, reading the signals of sensors, calibrating and initializing the sensors, and integrating the angular velocity signals with acceleration signals through the complementary filter to obtain high-precision angle. The inertial sensor, which is MPU9150, including three-axis accelerometer and three-axis gyroscope, is responsible for data collection. After processing the data, microcontroller sent the calculated angle to the PC (graphical interface implemented by MFC programming) for display via Bluetooth wireless transmission...