In order to solve the problem of the control precision of the intelligent wheelchair

a head pose control system based on the giant magnetoresistance（GMR） sensor calibration and fusion is designed. The system uses STM32 F103 as the hardware platform

using the four element method to describe the attitude information

attitude is calculated by output angular of three axis gyro. Because the drift error of the gyro is accumulated with time

the optimal convergence step is calculated by the gradient descent method

and the error of the gyro drift is corrected by successive iteration. The experimental results show that the sensor calibration process is correct and effective

and the drift error is reduced. The control system can accurately control the movement of the intelligent wheelchair.