组合式自解耦压电薄膜三维力传感器研制

Development of Combined Self-Decoupling Piezoelectric Thin Film Three-Dimensional Force Sensor

针对传统三维力传感器存在的非线性误差、维间耦合误差过大等瓶颈问题,面向重载、高频、强冲击三维力的测量需求,基于聚偏氟乙烯(PVDF)压电薄膜,结合并联分载原理,创新性的利用冲击力产生的倾覆力矩,设计了立柱菱形布局的压电薄膜三维力传感器结构,立柱菱形布局时具有抵消维间耦合能力,每个立柱近似只受单个倾覆力矩的影响,故可进行组合测量。探究了PVDF压电薄膜的最优布置,采用理论分析、有限元仿真分析和实验验证相结合的方法,对传感器设计方案的可行性进行了验证。研制了组合式自解耦压电薄膜三维力传感器样机,分别对其进行准静态标定实验和动态标定实验,实验结果表明,改进后传感器具有高灵敏度、高固有频率等特点,3个方向非线性误差均小于0.2%,维间耦合误差在1.2%以内,其结构设计具备抵消维间耦合的能力。该三维力传感器在高精密轴承钢球冷镦成型及瞬态强冲击等场景下有着重要的应用价值及潜力。

Given the bottleneck problems of a traditional three-dimensional force sensor,such as non-linear error and large error of inter-dimensional coupling,and the measurement demand of the three-dimensional force with heavy load,high frequency,and strong impact,a piezoelectric thin film three-dimensional force sensor with a diamond configuration of pillars is designed by innovatively using the overturning moment generated by impact force based on polyvinylidene fluoride(PVDF)piezoelectric thin film and combined with parallel load sharing principle.The diamond configuration of the pillars enables the sensor to compensate for inter-dimensional coupling.Each pillar is approximated to be affected by a single overturning moment and therefore combined measurements can be made.The optimal arrangement of PVDF piezoelectric thin films is investigated.The feasibility of the sensor design scheme is verified by combining theoretical analysis,finite element simulation analysis and experimental verification.A combined self-decoupling piezoelectric thin film three-dimensional force sensor prototype is developed.Quasi-static and dynamic calibration experiments are carried out respectively.The experimental results show that the improved sensor has the characteristics of high sensitivity and high natural frequency,the three-direction non-linear error is less than 0.2%,and the inter-dimensional coupling error is less than 1.2%.Its structure design can counteract the inter-dimensional coupling.The three-dimensional force sensor has important application value and potential in high-precision bearing ball cold upsetting and transient strong impact scenarios.