Research on extraction method of axis angle rate of stable platform based on FPGA

Aiming at the absolute photoelectric encoder used in the stable platform, a FPGA-based scheme which can read encoder data and measure velocity is proposed. The scheme uses the nonlinear tracking differentiator theory to design the speed measurement of the stable platform, which can avoid the error amplification caused by the conventional differential speed measurement. And this solution can implement in engineering easily because it does not require additional hardware circuitry. Numerical simulation analysis and experimental results show that the scheme can accurately read the encoder signal and estimate the encoder’s angular rate based on the position signal. The experiment proves that the method is accurate and effective.