静电力反馈微加速度计的吸合失效

静电力反馈微加速度计的敏感质量与固定结构部分因静电力作用发生吸合失效,严重影响加速度计的可靠性。为根本解决吸合问题,分析了加速度计在开环、闭环的不同工作状态下发生吸合的机理,推导出由静电力、机械刚度和止挡间隙等参数确定的3个稳定条件,用于判断吸合是否发生。实验证明了稳定条件是正确的。工程实际中,3个稳定条件可以指导此类加速度计的可靠性设计,通过选择合理的机械及电气参数,可以完全避免发生吸合失效。

Pull-in failures of electrostatic force feedback micro accelerometers

Pull-in failures of electrostatic force feedback micro accelerometers occur when the electrostatic force can not overcome the adhesion of the moveable sensing mass to the wall.Pull-in failures are the main cause of failures in micro accelerometers.Remedies for such failures were developed by analyzing the pull-in failure mechanisms for open-loop and closed-loop active controls.Three stability conditions were found to be functions of the electrostatic force,the mechanical stiffness,the stopper gap,and other parameters.These conditions can be used to judge whether pull-in failure will occur.Experiments show that the stability conditions are accurate so they can be used to design reliable micro accelerometers.Proper choices of the structural and electrical parameters can entirely eliminate pull-in failures.