Stewart式六维力传感器轻量化设计

Lightweight design of Stewart type six-axis force sensor

空间复合力测量是空间感知技术的重要发展方向之一。六维力传感器作为主要的空间复合力测量装置,被广泛应用于火箭发动机推力测试、航天器对接等领域。目前,轻量化已成为六维力传感器的主要研究方向之一,但由于其设计指标多且各项指标间存在相互制约,故采用理论推导、数值仿真及实验验证相结合的方法进行研究。首先,利用螺旋理论建立Stewart式六维力传感器在理想条件下的力映射模型,通过求解综合性能目标函数来确定其各向同性度理论最优时的结构参数。然后,利用ABAQUS有限元分析软件构建Stewart式六维力传感器仿真模型,并对其初始样机的质量、刚度、强度和灵敏度进行了详细分析;在此基础上,分析了上、下加载盘主要结构参数对传感器质量、刚度和强度的影响,进而对加载盘结构参数进行了优化并设计了一种具有正四面体特征的半球形减重结构,实现了传感器的轻量化设计。最后,对优化后Stewart式六维力传感器的性能进行了仿真分析和实验验证。结果表明,基于多目标参数优化结合数值仿真、实验验证可有效提高设计效率和降低设计成本;所设计的减重结构可有效改善Stewart式六维力传感器的质量分布和提高其质量利用率,优化后传感器的质量减小了17.65%且综合性能优异。研究结果可为六维力传感器的轻量化设计和综合性能优化提供参考。

Spatial composite force measurement is one of the important development directions of spatial sensing technology. As a main spatial composite force measuring device, the six-axis force sensor is widely used in rocket engine thrust test, spacecraft docking and other fields. At present, lightweight has become one of the main research directions of six-axis force sensors. However, due to the large number of design indicators and mutual constraints among various indicators, the method of theoretical derivation, numerical simulation and experimental verification was adopted in the research. Firstly, the force mapping model of Stewart type six-axis force sensor under ideal conditions was established based on the spiral theory, and the structural parameters when the theoretical isotropy was optimal were determined by solving the comprehensive performance objective function. Then, the simulation model of Stewart type six-axis force sensor was built by using the ABAQUS finite element analysis software,and the mass, stiffness, strength and sensitivity of its initial prototype were analyzed in detail. On this basis, the influence of the main structural parameters of upper and lower loading plates on the mass,stiffness and strength of sensor was analyzed, the structural parameters of upper and lower loading plates were optimized, and a hemispherical weight reduction structure with regular tetrahedron characteristics was designed, which realized the lightweight design of sensor. Finally, the performance of optimized Stewart type six-axis force sensor was simulated and verified by experiments. The results showed that multi-objective parameter optimization combined with numerical simulation and experimental verification could effectively improve design efficiency and reduce design cost;the designed weight reduction structure could effectively improve the mass distribution of Stewart type six-axis force sensor and improve its mass utilization. After optimization, the mass of the sensor was reduced by 17.65% and its comprehensive performance was excellent. The research results can provide reference for lightweight design and comprehensive performance optimization of six-axis force sensors.