Impossible is easy
The aim of this project is to learn sensor fusion algorithms and implement them on ARM microcontroller.
GY-80 is a cheap sensor board. Available on Ebay and DealExtreme.
Board feature 4 sensors providing in total 10-dimensional information.
The purpose of this project is to provide sensor fusion solution using low-cost sensor board.
-turn on/off plotting value
cclears the window
Following graph show angle measurement using accelerometer (red) and gyroscope (blue). Gyro clearly shows error-induced drift.
Complementary filter is a good alternative for small systems. http://web.mit.edu/scolton/www/filter.pdf
While both methods provided unbiased value, the Kalman filter provided more stable readout. Present-day MCUs provide sufficient power to use Kalman filter in real-time.
The robot consists of 5 parts: Tamiya gearbox, double H-bridge driver, Bluetooth wireless module, Stellaris launchpad board and GY-80 sensor board. The power is provided externally.
GY-80 board provides accelerometer and gyro sensor measurement at 100 [Hz] (UPS variable). Sensor data is then processed by kalman filter and feed into PI controller. Control signal is driving PWM output driving motors H bridges.
Robot operation. Red - accelerometer angle. Green - Gyro angular acceleration. Blue - estimated angle. Yellow - PI control signal.