# Dynamic Modeling and Characteristic Analysis of Articulated Steering Vehicles
###### Abstract  
Articulated steering vehicles (ASVs), with brilliant maneuverability and efficiency, are being widely applied in mining, construction, agriculture, and forestry. However, their special structures result in them having complex dynamic characteristics, but there are no reliable models for further research. This study established a simulation platform with the dynamic model of ASVs, where the subsystems of the power train, steering systems, tires, and frames were also included. The dynamic model was validated with field test data of typical working cycles, in which the focus was on longitudinal and lateral motions and the characteristics of steering and power train systems. Then, the distribution of hydraulic and drive power was revealed using the simulation platform and test data. For a load-haul-dump (LHD) vehicle  
However, the kinematics and dynamics of ASVs are quite different from those of conventional commercial vehicles. For ASVs, the structure contains two frames, which are articulated with each other, and each frame is equipped with an axle. They are usually all-wheel drive in order to obtain an excellent power performance. The steering function is realized by the articulated motion of the frames in the vertical direction. During the process of steering, the frames form a specific geometric relationship, and the kinematic model of ASVs can be obtained by assuming no slip [12]. However, lateral slip is always inevitable during the steering process. Oscillation, snake-like running, jack-knifing, and related problems are considered to be dynamic instability. Although some models could be used to analyze the stability of ASVs, the transient characteristics of the steering system have not been covered. [PERSON] et al. [13] researched the stability of ASVs based on a two-degree-of-freedom (DOF) and a three-DOF model, in which the difference of the two models was the yaw freedom of frames. The results stated that the leakage of hydraulic fluid affected stability in different modes of instability. Therefore, the impact of the steering system on dynamic responses is particularly critical, and the model should be detailed. The steering system of an ASV is usually powered by a hydraulic cylinder, which is controlled by a hydraulic valve. The model involves the coupling of a hydraulic system and the connected frames. [PERSON] et al. [14] developed a 12-DOF model of ASVs with Adams/View software, in which the detailed hydrostatic steering control unit was involved. The instability of snaking and oscillation was confirmed, and improvements were made with the yaw moment and driving force distribution control. Although this research mainly focused on lateral responses, the validation also concentrated on lateral motions. The research of [15] indicated that the lateral response also depended on longitudinal velocity ranges. In addition, the valve-controlled steering system is more universal. Therefore, a universally applicable model of ASVs should be presented holistically [16], and the validation of the model should be performed comprehensively [17]. Although traditional diesel-engine-driven ASVs provide excellent power and mobility, exhaust emissions are inevitable. In addition to the increasing cost of fuel, the requirement of environmental quality has also eliminated the usage of this type of ASV. Such as in underground mines, many pieces of ventilation equipment are needed to deal with the emissions of ASVs, i.e., of LHD vehicles, articulated trucks, drilling rigs, and so on. Some plug-in ASVs have been used in the working faces of underground mines; although the power was guaranteed by the towed cable, the mobility of the ASVs was severely restricted [18]. In order to address emission problems, the power of ASVs was improved with hybrid or pure electric power structures [19]. For hybrid power ASVs, the diesel engine is used to drive the generator, and the battery, supercapacitor, or both are used to store the energy of the power system [20].