基于卡尔曼滤波的锁相环算法研究

在某卫星载荷—感应式磁力仪的设计中，需要提取高动态环境下的磁场信号并降低所获信号的噪声干扰。基于此提出了一种改进的基于卡尔曼滤波的锁相环设计算法并应用于感应式磁力仪数据处理单元DSP的软件设计中，设计采用扩展卡尔曼滤波方法结合传统全数字软件锁相环的方法对待测信号进行滤噪、跟踪，获取信号的频率信息并通过锁相放大器获取信号的幅值、相位信息，并进行了仿真和实验验证。实验结果表明，改进的锁相环可以有效的对多普勒频率变化率为f=500Hz/s，信噪比低至-20dB的信号进行跟踪。该方法已应用于感应式磁力仪地面设备的信号检测和提取。

Research on the locking loop algorithm based on kalman filter

In the design of a satellite load magnetometer, it is necessary to extract the magnetic signal in high dynamic environment and reduce the noise interference. In order to improve the reliability of signal and avoid the situation of false lock and jitter in the acquisition of reference signal under the high noise and high dynamic environment, a new method that combines traditional software Phase-locked Loop and Extended Kalman filter to obtain the small-signal covered by noise is proposed. The proposed method provides an effective approach to improve the accuracy of the small-signal. Experimental results show that proposed method can track the Signal effectively when the rate of Doppler frequency is 500Hz/s and SNR is -20dB.