Conceptualization, T.Z. and Y.Y.; methodology, T.Z. and Y.Y.; software, T.Z., Y.Y., H.M. and Y.C.; validation, T.Z. and Y.Y.; formal analysis, T.Z., Y.Y., H.M. and Y.C.; investigation, T.Z. and Y.Y.; resources, T.Z. and Y.Y.; data curation, Y.Y.; writing—original draft preparation, T.Z. and Y.Y.; writing—review and editing, T.Z., Y.Y., H.M. and Y.C.; visualization, T.Z. and Y.Y.; supervision, T.Z.; project administration, T.Z.; funding acquisition, T.Z. All authors have read and agreed to the published version of the manuscript.

Figure 1. Six-wheel distributed unmanned vehicle path-tracking kinematic model.

Figure 1. Six-wheel distributed unmanned vehicle path-tracking kinematic model.

Figure 2. Coordinated control strategy of the distributed unmanned vehicle with a fully electric drive.

Figure 2. Coordinated control strategy of the distributed unmanned vehicle with a fully electric drive.

Figure 3. Design a fuzzy controller flow diagram.

Figure 3. Design a fuzzy controller flow diagram.

Figure 4. Slip rate controller based on adaptive fuzzy PID.

Figure 4. Slip rate controller based on adaptive fuzzy PID.

Figure 5. Six-wheeled distributed unmanned vehicle dynamics model.

Figure 5. Six-wheeled distributed unmanned vehicle dynamics model.

Figure 6. Simulation module under MATLAB/Simulink.

Figure 6. Simulation module under MATLAB/Simulink.

Figure 7. Six steering motion modes of six-wheel distributed unmanned vehicle: (a) four-wheel Akerman steering; (b) two-wheel Akerman steering; (c) crab walking; (d) differential steering; (e) differential center steering; (f) center steering. The direction of the red arrow is the direction of the wheel movement.

Figure 7. Six steering motion modes of six-wheel distributed unmanned vehicle: (a) four-wheel Akerman steering; (b) two-wheel Akerman steering; (c) crab walking; (d) differential steering; (e) differential center steering; (f) center steering. The direction of the red arrow is the direction of the wheel movement.

Figure 8. Split mu straight road. The yellow arrow represents the force on the wheel in the z-axis direction.

Figure 8. Split mu straight road. The yellow arrow represents the force on the wheel in the z-axis direction.

Figure 9. Path tracking comparison chart on the split mu straight road.

Figure 9. Path tracking comparison chart on the split mu straight road.

Figure 10. Speed tracking comparison chart on the split mu straight road.

Figure 10. Speed tracking comparison chart on the split mu straight road.

Figure 11. Comparison chart of heading angle tracking on the split mu straight road.

Figure 11. Comparison chart of heading angle tracking on the split mu straight road.

Figure 12. Transverse pendulum angular velocity tracking comparison chart on the split mu straight road.

Figure 12. Transverse pendulum angular velocity tracking comparison chart on the split mu straight road.

Figure 13. Speed tracking curves of unmanned vehicles at different speeds on the split mu straight road.

Figure 13. Speed tracking curves of unmanned vehicles at different speeds on the split mu straight road.

Figure 14. Path tracking curves of unmanned vehicles at different speeds on the split mu straight road.

Figure 14. Path tracking curves of unmanned vehicles at different speeds on the split mu straight road.

Figure 15. Wheel slip rate of the distributed unmanned vehicle at 50 km/h on the split mu straight road.

Figure 15. Wheel slip rate of the distributed unmanned vehicle at 50 km/h on the split mu straight road.

Figure 16. Sine sweep straight road. The yellow arrow represents the force on the wheel in the z-axis direction.

Figure 16. Sine sweep straight road. The yellow arrow represents the force on the wheel in the z-axis direction.

Figure 17. Path tracking comparison chart on the sine sweep straight road.

Figure 17. Path tracking comparison chart on the sine sweep straight road.

Figure 18. Speed tracking comparison chart on the sine sweep straight road.

Figure 18. Speed tracking comparison chart on the sine sweep straight road.

Figure 19. Comparison chart of heading angle tracking on the sine sweep straight road.

Figure 19. Comparison chart of heading angle tracking on the sine sweep straight road.

Figure 20. Transverse pendulum angular velocity tracking comparison chart on the Sine sweep straight road.

Figure 20. Transverse pendulum angular velocity tracking comparison chart on the Sine sweep straight road.

Figure 21. Speed tracking curves of unmanned vehicles at different speeds on the sine sweep straight road.

Figure 21. Speed tracking curves of unmanned vehicles at different speeds on the sine sweep straight road.

Figure 22. Path tracking curves of unmanned vehicles at different speeds on the Sine sweep straight road.

Figure 22. Path tracking curves of unmanned vehicles at different speeds on the Sine sweep straight road.

Figure 23. Wheel slip rate of distributed unmanned vehicles at 50 km/h on the sine sweep straight road.

Figure 23. Wheel slip rate of distributed unmanned vehicles at 50 km/h on the sine sweep straight road.

Table 1. The main parameters of 6WID/4WIS UGV.

Table 1. The main parameters of 6WID/4WIS UGV.

ParametersValuesUnitsSprung mass2900kgGravitational acceleration9.8m/s2The horizontal distance between the center of gravity and the front axle 2mThe horizontal distance between the front axle and the middle axle2.2mThe horizontal distance between the rear axle and middle axle2.2mWheelbase2200mmHeight of center of gravity1.25mTire diameter0.996mTire width0.309mPower of in-wheel motor65kWMaximum off-road speed45(km/h)Sampling period5ms