并联式六维加速度传感器中相对、绝对运动的影响关系

Influence relationship between relative motion and absolute motion in parallel type six-axis acceleration sensor

六维加速度传感器的传统解耦过程复杂、计算效率低,根本原因是其内部的相对运动依赖于外部绝对运动。鉴于此,以四种构型的并联式六维加速度传感器为例,剖析了上述两类运动之间的影响关系。运用ADAMS软件强大的动力学仿真功能,分析了传感器在不同驱动条件下的输入、输出结果,揭示了因忽略相对运动而引入的相对误差与输入运动中线加速度、角加速度的幅值、频率之间的关系;进一步地,通过计算并对比并联机构雅可比矩阵的条件数,解释了不同构型的关系存在差异的原因。结果表明:激励加速度幅值对解耦计算精度影响较低,由此造成的误差不超过0.001%;解耦算法中能否忽略质量块相对于基座的运动,主要由激励加速度的频率决定,且构型雅可比矩阵条件数越接近于1,由此带来的相对误差就越小。研究结果为六维加速度传感器解耦算法的优化提供了理论参考。

Traditional decoupling process of six-dimensional acceleration sensor is complex and its calculation efficiency is low.The basic reason is that its internal relative motion depends on the external absolute motion.In view of this,taking four types of parallel six-dimensional acceleration sensors as an example,influence relationship between the two kinds of motions is analyzed.Using the dynamic simulation function of ADAMS software,the input and output results of the sensor under different driving conditions are analyzed.The relationship between the relative error caused by neglecting the relative motion and the amplitude and frequency of the linear acceleration and angular acceleration is revealed.Furthermore,by calculating and comparing the condition number of the Jacobian matrix,the reason for the difference of the relationship of different configurations is explained.The results show that the influence of the amplitude of excitation acceleration on the precision of decoupling calculation is low,and the error caused by this is less than 0.001%.Whether the motion of mass block relative to the base can be ignored in decoupling algorithm mostly depends on the frequency of excitation acceleration,and the closer the condition number of configuration Jacobian matrix is to 1,the smaller the relative error is.The research results provide a theoretical reference for the optimization of decoupling algorithm of six-dimensional acceleration sensor.