并联式六维加速度传感器故障诊断与修复

Fault diagnosis and restoration for parallel type six-axis accelerators

通过引入"辅助角速度",将并联式六维加速度传感器的二阶非线性动力学方程组化为一阶线性微分方程组,实现了动力学方程的完全解耦。通过运用并联机构的正向运动学理论推导系统输入量之间的固有约束关系,建立起该传感器故障诊断的模型,并给出具体的可修复故障组合。定义一种故障诊断修复率的概念,对传感器故障的可修复性进行量化,发现传感器的故障诊断修复率较低。基于此,提出一种改进的并联式六维加速度传感器构型,依据故障自诊断模型归纳出故障判定方程并结合故障树分析法进行故障诊断,对具体的故障工况提供故障修复方案,结果表明,相较于原结构,并联式六维加速度传感器故障诊断修复率提高了28%。运用ADAMS软件仿真验证,结果显示故障支链修复后的综合误差不超过6.38%,验证了所提出的故障诊断及修复方案的正确性和可行性。

By introducing an auxiliary angular velocity,dynamic differential equations of a parallel type six-axis accelerator were transferred from second-order nonlinear ones into a group of first-order linear equations fully decoupled.Using the forward kinematics theory of a parallel mechanism,the inherent constraint relations among the system inputs were derived,then the fault diagnosis model of this sensor was built and specific groups of faults being able to be restored were obtained. A concept of fault diagnosis restoring rate was defined to quantize the sensor's recoverability,the sensor's restoring rate was found to be lower. An improved parallel type six-axis accelerator configuration was proposed.According to its fault self-diagnosis model,a fault-judgement equation was concluded and combined with the fault tree analysis,its faults were diagnosed and the troubleshooting schemes for specific fault conditions were provided. The results showed that compared with the original structure,the restoring rate of the parallel type six-axis accelerator increases by 28%. Using the software ADAMS,simulations were done,the results showed that the comprehensive error is less than 6.38% after the fault branch chain is restored; the correctness and feasibility of the proposed fault diagnosis and restoring schemes are verified.