Nanonewton-Level Thrust Measurement Based on Stiffness Adjustment Through Total Variation Denoising Under Heavy Loads

Sub-micronewton thrusters on space satellites are widely used in spaceborne gravitational wave detection, making accurate measurement of microthrust-generated thrust essential. Moreover, micropropulsion systems often exhibit substantial mass, posing challenges for thrust measurement. This article prompted the development of a sub-microthrust measurement device based on the inverted pendulum principle, which withstands 8-kg loads and boasts a large thrust-to-weight ratio exceeding 10⁹. The experimental results demonstrate that adjusting the stiffness of the inverted pendulum can effectively enhance the resolution of the device. Piecewise constant signal (PCS) thrust force was introduced, and the nonlinear total variation denoising (TVD) algorithm method was adopted for signal denoising. It is validated that thrust measurement in the range of 0– $261~\mu $ N is achieved with a minimum resolution of 24nN. The device design and stiffness adjustment method proposed in this article, as well as the data denoising method utilized, greatly enhance the thrust resolution measurement. This approach enables the development of an accurate microthrust model for spaceborne gravitational wave detection missions while simultaneously offering a novel solution for sub-micronewton-level thrust measurement under heavy-load conditions.