Error modelling and experimental validation for a new-type series-parallel stable platform

Abstract. To provide a highly stable reference plane for navigation and aiming systems on moving carriers, this paper presents a novel three-degrees-of-freedom (3-DoF) series-parallel stabilisation platform (SPSP). This platform effectively eliminates longitudinal and lateral carrier sway while dynamically adjusting azimuth angles for target tracking. We designed the SPSP configuration and analysed its kinematic degrees of freedom (DoF). Based on the mechanism's operating principles, factors influencing the moving platform's attitude error (AE) were systematically investigated, and an error model was established using partial differential methods. Simulation studies quantified the impact of individual error sources on AE, enabling rational error allocation. Critical factors affecting rod length error (RLE) were identified, leading to proposed methods for enhancing the accuracy of gear and lead screw transmissions. An experimental platform was constructed using a dSPACE hardware-in-the-loop simulation system. Validation experiments included electromechanical actuator precision tests, open-loop SPSP positioning tests, and closed-loop stability tests, confirming the error model's validity and configuration design rationality.