Position tracking control of a permanent magnet steering wheel equipped to a vertical tank robot: From theory, simulation to practice

In the domain of mobile robots (MRs) utilizing multi-wheel directional control, position synchronization in steering wheels remains a challenging problem, particularly when implemented in permanent magnet steering wheels for vertical tank robots. Addressing this critical problem, this paper presents a position synchronization control strategy that integrates a mean deviation coupling strategy (MDCS) with state feedback tracking control (SFTC) enhanced by integral action. In essence, MDCS minimizes position synchronization errors, especially during deviations or fluctuations, while SFTC enables fast responses to state changes and improves adaptability in uneven terrain. Combined with integral action, SFTC compensates for static errors, enhancing long-term stability. Furthermore, to establish robust evidence for the proposed strategy, this paper validates the results through both simulation and experimental analysis. Initially, simulation results show that integrating the MDCS with SFTC improves settling time, reducing it from 0.6 to 0.4 s. Additionally, experimental tests demonstrated that the improvement in settling time closely matched the simulation results during the reference angle change phase, excluding the initial startup phase. Without the synchronization strategy, the settling time was 0.5 s, whereas applying the control strategy increased it to 0.7 s. This discrepancy arises from the selected MDCS control coefficients, which were not well-suited to the actual system, leading to ineffective compensation signal intervention. As a result, the system dynamics were altered, and the stability of the poles was no longer ensured compared to the original selection. It can be concluded that the integration of MDCS with SFTC holds strong potential for practical application in steering wheels, improving synchronization while reducing the computational burden on hardware.