End-to-End Design and Validation of a Low-Cost Stewart Platform with Nonlinear Estimation and Control

TL;DR

The paper addresses the need for an affordable, research- and education-friendly six-degree-of-freedom Stewart platform. It delivers an end-to-end design that combines off-the-shelf hardware with custom components and a software stack that unifies kinematic and dynamic modeling, EKF state estimation, and a nonlinear control strategy based on feedback linearization and LQR. The proposed framework is validated through both high-fidelity simulations and hardware experiments on static and dynamic trajectories, demonstrating accurate trajectory tracking and real-time state estimation under sensor noise. With a total prototype cost around USD $1,890.85, the work provides a practical, scalable platform for advanced control and estimation studies in robotics education and research.

Abstract

This paper presents the complete design, control, and experimental validation of a low-cost Stewart platform prototype developed as an affordable yet capable robotic testbed for research and education. The platform combines off the shelf components with 3D printed and custom fabricated parts to deliver full six degrees of freedom motions using six linear actuators connecting a moving platform to a fixed base. The system software integrates dynamic modeling, data acquisition, and real time control within a unified framework. A robust trajectory tracking controller based on feedback linearization, augmented with an LQR scheme, compensates for the platform's nonlinear dynamics to achieve precise motion control. In parallel, an Extended Kalman Filter fuses IMU and actuator encoder feedback to provide accurate and reliable state estimation under sensor noise and external disturbances. Unlike prior efforts that emphasize only isolated aspects such as modeling or control, this work delivers a complete hardware-software platform validated through both simulation and experiments on static and dynamic trajectories. Results demonstrate effective trajectory tracking and real-time state estimation, highlighting the platform's potential as a cost effective and versatile tool for advanced research and educational applications.

Figures (15)

• Figure 1: Examples of commercially-developed Stewart platforms (sources: acromeStewartptactuator2025motionsystems2025).
• Figure 2: The constructed prototype of the Stewart platform.
• Figure 3: Custom-designed PCB that interfaces the myRIO-1900 with motor driver and actuators.
• Figure 4: System configuration of the Stewart platform.
• Figure 5: Joint configurations of the platform: joint $b_i$ positions on {B} (left) and joints $p_i$ position on {P} (right).