加速度传感器信号增益的软件实时控制

摘要

针对压电加速度传感器信号调理电路中标定过程繁琐、标定效率低下、系统在运行过程中输出信号增益不能改变的问题,提出了在前级电荷放大器之后添加一级可变增益运算放大器来实现输出信号增益的实时控制.利用微处理器上集成的模拟数字转换模块(A/D)检测压电加速度传感器输出信号的幅值,同时采用其集成的电流模式数/模转模块(IDAC)对变增益运算放大器进行控制,控制传感器输出信号幅值在预期范围.通过此电路在传感器电路标定和弹丸完整弹道过载信号的采集两方面应用试验,表明该方法能够方便、准确实时调整压电加速度传感器输出信号的增益,符合使用要求.%There are several problems in the previous studies of the calibration process for signal conditioning circuits of piezoelectric acceleration sensor,such as tedious procedure and low efficiency. Besides,the output signal gain of signal conditioning circuit cannot be adjusted during the running process. To solve those problems, this paper describes a new method that a variable gain operational amplifier controlled by a micro controller is employed behind the prime charge amplifier to achieve real-time control of the output signal gain. The output signal of acceleration sensor is detected by using the analog to digital conversion module ( A/D ) integrated on the microprocessor, and the variable gain operational amplifier is controlled to keep the output amplitude of the sensor in the expected range by the current mode D/A switch module (IDAC)on the microprocessor simultaneously. The proposed circuit was used in two applications including the calibration of sensor circuit and acquisition for the overload signal of complete ballistic projectile, which can show this method can be used conveniently and accurately in the real time adjustments of piezoelectric acceleration sensor output signal gain and meet the application requirements.