Performance Study of the Six-Component Piezoelectric Helicopter Rotor Balance Vector Test System Considering the Influence of Assembly Error

The rotor system is a crucial component in the design and manufacture of helicopters. Accurate measurement of the output aerodynamic forces of the rotor system is indispensable to ensure high maneuverability and stability of the aircraft during service. To overcome the challenge of measuring the high-frequency harmonic loads on rotor blades due to their rotation, this paper presents a rotor balance based on the piezoelectric measurement principle for precise measurement of rotor dynamic loads. This device adopts a planar four-point support structure, featuring high precision, high rigidity, and fast response speed. By establishing a theoretical mechanical model of the piezoelectric balance and analyzing and decoupling its force state, the main factors influencing its performance variations are obtained. Secondly, in response to the uneven height issue existing in the assembly process of piezoelectric components, ANSYS simulation software was utilized to conduct overall parameter optimization and investigate the influence of assembly errors. Additionally, modal and static simulation analyses were carried out to finalize the overall optimization plan for the measurement device. Additionally, a self-developed three-direction force calibration device is employed to conduct static calibration and exploration of the natural frequency of four piezoelectric elements and the balance system. The static and dynamic performance of the rotor vector measurement system has been verified through experiments, and it meets the test requirements. The linearity and repeatability errors of all forces and moments are less than 1.00%, and the natural frequency is higher than 900 Hz. This device can offer theoretical basis and reference for subsequent high-precision measurement of rotor systems and the design of balances.