Distributed Backstepping Integral Terminal Sliding Mode Control for Consensus Speed Tracking in Networked Permanent Magnet Synchronous Motor Systems

This paper develops distributed Backstepping Integral Terminal Sliding Mode (BITSM) control for consensus speed tracking of networked Permanent Magnet Synchronous Motor (PMSM) drives under bounded matched uncertainty. A leader–follower speed loop supplies the q-axis current reference, and local integral terminal sliding surfaces regulate the dq currents. Under explicit disturbance and estimator-error bounds, unsaturated continuous-time analysis gives finite-time surface reaching; an input-to-state-stability argument then bounds the physical speed error, with topology dependence exposed through the pinned graph matrix. Sampling, saturation, delay, packet loss, and unmodelled implementation effects are treated as practical limitations rather than covered by the exact theorem. Four-agent simulations show about 83% lower peak transient speed spread and more than 90% lower steady-state inter-agent spread for the reported cases. Archived two-drive traces also show a 91.5% lower selected loaded-agent steady-state consensus RMSE than the reported PID comparator, while the unloaded agent does not improve in every region. Because source code, raw samples, matched-bandwidth tuning, repeated trials, and an independent rerun of the corrected law are unavailable, this last arithmetic contrast is descriptive and is not claimed as causal superiority or experimental certification of the corrected controller.