Time Delay Estimation Control of Permanent Magnet Spherical Actuator Based on Gradient Compensation

Abstract

A multi-degree-of-freedom Permanent Magnet Spherical Actuator (PMSpA) has a special mechanical structure and electromagnetic fields, and is easily affected by nonlinear disturbances such as modeling errors and friction. Therefore, the quality of a PMSpA control system may be deteriorated. In order to keep the PMSpA with good trajectory tracking performance, this paper designs a time delay estimation controller based on gradient compensation. Firstly, the dynamic model of the PMSpA with nonlinear terms is derived. The nonlinear terms in the complex dynamic model can be simplified and estimated by the time delay estimation method. Secondly, for the estimation errors caused by time delay control, a gradient compensator is introduced to further correct and compensate for it. Furthermore, the stability of the designed controller is proved by the Lyapunov equation. Finally, the correctness and effectiveness of the controller are validated by comparison with other controllers through simulation. In addition, experimental results have also shown that the control accuracy of the spherical motor can be effectively improved using the proposed controller.

Adaptive Neural Network Global Fractional Order Fast Terminal Sliding Mode Model-Free Intelligent PID Control for Hypersonic Vehicle’s Ground Thermal Environment

“…Notably, TDE does not introduce any system delays. Owing to TDE's inherent advantages, it has been widely adopted in various systems, including permanent magnet motors [14], lower limb exoskeletons [15] and tri-rotor unmanned aerial vehicles [16]. In [17,18], both the robotic arm and HVAC systems were governed by a model-free intelligent PID based on TDE (TDE-MFIPIDC).…”

Symmetric Nonlinear Feedback Control and Machine Learning for Sustainable Spherical Motor Operation

“…Nicholas Minorsky's 1922 groundbreaking work on three-term or PID controllers and James Watt's introduction of the 16th century Ctrifugal Governor laid the foundations for modern feedback control techniques [22]. There are various control schemes for sphere engines, with joint and operational space control being prominent approaches, each addressing specific mechanical design aspects [23][24][25][26][27][28][29][30][31]. Joint space control focuses on the design of feedback controllers that closely align the actual movement and the desired movement, typically converting the desired movement into a joint variable and controlling each joint independently.…”