Coordinated Control of Hydraulic Distributed Drive in an All-Terrain Tracked Vehicle Under Articulated Steering Constraints

Coordinating four independent hydrostatic circuits in a dual-body articulated all-terrain tracked vehicle requires track-speed allocation accommodating articulation kinematics and propulsion-load distribution. Geometric speed matching alone can concentrate propulsion loads on the front body, induce rear-body drag and track slip, and elevate circuit pressure differences. This study proposes differential-projection coordinated control (DPCC) to address this coupling. Nominal four-track speeds incorporating body sideslip are derived from articulation-point velocity compatibility, and circuit pressure deviations drive load redistribution through bounded zero-sum projection. Conditions for conservation of the target track-speed sum and bounded differential-speed deviations are established, elucidating load imbalance under geometric matching and load redistribution through small track-speed adjustments. Simulations at 0–30° show that DPCC reduces peak circuit pressure difference and root-mean-square (RMS) slip ratio at all six nonzero steady-state articulation angles relative to conventional geometric differential control. At 30°, peak pressure difference decreases from 34.16 to 15.55 MPa, RMS slip ratio from 0.59% to 0.40%, and RMS vehicle-speed error by 74.05%, while average rear-body drag becomes forward propulsion. A full-scale steering test at 10° and 5.00 m/s supports the feasibility of DPCC and shows the higher outer-circuit pressures predicted by simulation. Experimental observations and multi-condition simulations jointly support the proposed coordination mechanism.