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Wheeled mobile robots are widely implemented in the field environment where slipping and skidding may often occur. This paper presents a self-adaptive path tracking control framework based on a radial basis function (RBF) neural network to overcome slippage disturbances. Both kinematic and dynamic models of a wheeled robot with skid-steer characteristics are established with position, orientation, and equivalent tracking error definitions. A dual-loop control framework is proposed, and kinematic and dynamic models are integrated in the inner and outer loops, respectively. An RBF neutral network is employed for yaw rate control to realize adaptability to longitudinal slippage. Simulations employing the proposed control framework are performed to track snaking and a DLC reference path with slip ratio variations. The results suggest that the proposed control framework yields much lower position and orientation errors compared with those of a PID and a single neuron network (SNN) controller. It also exhibits prior anti-disturbance performance and adaptability to longitudinal slippage. The proposed control framework could thus be employed for autonomous mobile robots working on complex terrain.

A variety of axle suspension linkage configurations with hydropneumatic struts are increasingly being used in mining trucks to achieve improved ride comfort and higher operating speeds. In this study, relative kinematic properties of four different independent front axle suspensions are investigated together with their effects on the handling dynamics of a mining truck. These included a composite linkage (CL), a candle (CA), a trailing arm (TA) and a double wishbone (DW) suspension. The kinematic responses are integrated to a handling model of a mining truck to study their relative handling characteristics. The results suggest that the CL and DW suspensions yield responses respectively during the steady-turn and lane-change manoeuvres compared with the CA and TA suspensions. The CL suspension may be considered desirable for future designs of high-performance trucks owing to its superior anti-roll performance under both steady and transient steering inputs. This paper is a revised and expanded version of a paper entitled 'Relative performance analyses of independent front axle suspensions for a heavy-duty mining truck' presented at SAE 2014 Commercial Vehicle Engineering Congress (COMVEC), Rosemont, Illinois, USA, 7-9 October, 2014.

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