闭环微加速度计非线性补偿
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摘要
离心标定修正微加速度计的非线性存在周期长和成本高等缺点,寻找一种可以提高生产效率的修正办法具有重要意义。推导了理想情况下加速度计的工作原理,并对载波带来的附加静电力对测试结果的影响进行了分析。在引入闭环平衡时结构非对称因子后推导出导致非线性的公式,找到了影响闭环平衡后结构非对称的三个主要因数:寄生电容、结构本身不对称和伺服电路零位的偏差。分析了各个因素在闭环平衡状态对结构非对称的影响原理后,相应提出了提高加速度计线性度的方法。最后介绍了非线性补偿的工程实现方法,并对环境温度变化较大时的补偿方法给出了建议。实验表明,该技术切实可行,能将加速度计的非线性特性提高将近一个数量级。
There are many disadvantages to correct the nonlinearity of the accelerometer with centrifuges such as time-consuming,high cost and so on.It is meaningful to find an alternative method to improve the production efficiency.The operating principle of the accelerometer in the ideal case is deduced,and the effects of the additional electrostatic force exerted by the carrier on the test results are analyzed.The equation on resulting in the nonlinearity is deduced by conside-ring the closed-loop balanced structural asymmetry factor.Three main factors leading to the closed-loop structural asymmetry are located: the parasitic capacitance,asymmetry of structure itself and zero deviation of the servo circuit.After analyzing the effects of these factors above,the solutions are proposed accordingly to improve the linearity of the accelerometer.Finally,the engineering nonlinear compensation method is introduced,and the compensation method consi-dering large temperature variation is also suggested.The experimental results show that this technology can increase the nonlinearity of the accelerometer by about one order of magnitude.
There are many disadvantages to correct the nonlinearity of the accelerometer with centrifuges such as time-consuming,high cost and so on.It is meaningful to find an alternative method to improve the production efficiency.The operating principle of the accelerometer in the ideal case is deduced,and the effects of the additional electrostatic force exerted by the carrier on the test results are analyzed.The equation on resulting in the nonlinearity is deduced by conside-ring the closed-loop balanced structural asymmetry factor.Three main factors leading to the closed-loop structural asymmetry are located: the parasitic capacitance,asymmetry of structure itself and zero deviation of the servo circuit.After analyzing the effects of these factors above,the solutions are proposed accordingly to improve the linearity of the accelerometer.Finally,the engineering nonlinear compensation method is introduced,and the compensation method consi-dering large temperature variation is also suggested.The experimental results show that this technology can increase the nonlinearity of the accelerometer by about one order of magnitude.
引文
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[7]刘恒,何晓平,杜连明,等.一种梳齿力平衡式微加速度计[J].仪表技术与传感器,2012,6(6):16-18.
[8]万蔡辛,董景新,刘云峰.静电力反馈微加速度计的模拟控制器优化[J].清华大学学报,2009,49(11):1779-1781.
[2]吴天准,董景新,赵长德,等.梳齿式微机械加速度计闭环系统的线性度[J].机械工程学报,2006,42(12):128-129.
[3]ZUMER J,REYNAERTS D,BOLTEZAR M,et al.An ad-vanced nonlinear model of a low-g MEMS accelerometer for acomputer pen[J].Measurment,2012,45(3):459-468.
[4]乔仁晓,孟晓风,季宏.加速度计非线性项系数校准误差分析与建模[J].系统仿真学报,2008,20(6):1633-1634.
[5]何晓平.静电伺服微加速度计的量程设计[J].中国惯性技术学报,2003,20(6):90-93.
[6]吴天准,董景新,刘云峰.电容式微机械加速度计闭环系统的零偏[J].清华大学学报,2005,45(2):201-204.
[7]刘恒,何晓平,杜连明,等.一种梳齿力平衡式微加速度计[J].仪表技术与传感器,2012,6(6):16-18.
[8]万蔡辛,董景新,刘云峰.静电力反馈微加速度计的模拟控制器优化[J].清华大学学报,2009,49(11):1779-1781.