用于线圈磁轴测量的滤波放大电路的设计改进

Design and improvement of filter circuit for solenoid magnet axis measurement

为了提高脉冲紧线法的测量精确度,对测量系统中的信号处理电路进行改进,首先根据电路的幅频、相频响应得出导致信号畸变的原因,然后根据理论计算得到磁轴倾斜(Tilt)导致的振动波形是基波为30 Hz的方波,磁轴偏轴(Offset)导致的振动波形是5 ms的短脉冲叠加在Tilt波形的变化沿。新的信号处理电路可以实现30 Hz^3 000 Hz之间的信号等幅放大、无相移传输,基本实现了信号基波及主要谐波的无失真传输,使测量结果中磁轴偏轴和磁轴倾斜信号容易区分,减小了测量误差。

The signal processing circuit in pulse taut wire magnetic axis measurement system is improved in order to improve the measurement accuracy. Firstly, The reason of signal distortion is analyzed according to the amplitude frequency and phase frequency responses of the circuit. Then the theoretical computation results show that the Tilt error caused a 30 Hz square wave, and the Offest error caused an extra 5 ms pulse at the edge of the square. The proposed signal processing circuit, which can transfer signals from 30 Hz to 3 000 Hz undistortedly, satisfies the demands of this system. The measurement results show that the axis Tilt and Offest errors are easily to distinguish, and the measurement error is reduced.