A servo network architecture for deterministic real-time synchronization in wheeled mobile platforms: hardware design and communication-layer validation

In wheeled mobile (WM) platforms, coordinated multi-wheel motion requires that motion commands be dispatched to, and feedback collected from, several independently driven servo actuators with tightly bounded timing. Standard serial communication introduces non-deterministic delays, while commercial fieldbus systems that guarantee deterministic timing impose high cost and licensing complexity. To address this gap, our work proposes a servo-based real-time synchronization architecture for omnidirectional wheeled platforms, implemented directly at the hardware communication layer. The method supports all-wheel-drive (AWD) and four-wheel differential-drive (FWDD) configurations through a network of distributed servo motors operating under a real-time protocol over standard 100 Mbps Ethernet. A dedicated motion controller—integrating a microcontroller unit, a real-time protocol module, a physical-layer transceiver, and a pulse-transformation module—ensures deterministic command dispatch and synchronized feedback. A physical mobile platform and a custom control board are constructed, and the three-synchronization metrics (command dispatch, feedback alignment, and inter-servo timing) are measured experimentally. The results demonstrate sub-microsecond synchronization with low latency at the servo-network level. We emphasise that this timing synchronization is a necessary but not sufficient condition for physical trajectory accuracy: it removes command-dispatch skew as a source of coordination error, but end-to-end trajectory tracking additionally depends on mechanical factors (wheel–ground contact, gearbox compliance, load) and the motion-control law. Validation of trajectory accuracy under dynamic motion and manipulation load is accordingly identified as the subject of future work. The presented architecture provides an effective, low-cost, and accessible foundation for coordinated motion in advanced mobile platforms.