        Utility trucks are the first responders in extreme climate and weather situations, for saving people’s lives, for restoring electric power, and cutting trees, and restoring traffic on the roads. However, such trucks can increase the possibility of road accidents in many ways and, additionally, create dangerous situations on the roads, and off-road conditions, while moving, and performing tasks. Large bucket/boom trucks for reaching elevated heights can become unstable due to their geometry change, which can cause a drastic variation of the truck-boom system’s moment of inertia, and the extreme weight re-distribution between the wheels. Multiplied by the design instability of the utility trucks, such conditions may have a serious impact on the truck’s safety.

        Morphing capabilities of the utility trucks need to be investigated together with the vehicle-road forces in order to hold vehicle safe on the roads. By determining the smart morphological properties of the entire utility truck’s 3D perimeter, it is possible to achieve a better distribution of the normal load on the wheels and, thus, to provide more tire grip/traction and reduce the rolling resistance of the tires. 

        In this research paper, static analysis, range of the normal reaction and rolling resistance at each wheel of the utility truck is performed for uniform movements with a constant small velocity to characterize a safe working zone of the boom equipment when the truck is in an inclined, flat and tilted surface. The analysis is performed for a 5-degree of freedom boom equipment with revolute and translational joints in a complex constrained space given by the truck design. Possible morphing of the boom equipment constrained by the geometry design of the actual utility truck with the boom equipment is studied using 3D moment and force-vector analysis. The possible morphing configurations of the boom equipment is examined in order to define the static normal reactions and rolling resistance at the wheel-road interaction. The purpose of this study is to increase truck safety by avoiding the reduction of the wheel normal load to 20% of its value on a flat surface with the boom equipment in the transporting position. Another goal is to reduce the total rolling resistance of the truck by providing better distributions of the normal loads to the wheels. 

        Further, the morphing of the boom equipment was investigated to determine limiting configurations that can be reached without rolling over the truck. In this analysis, it is assumed that the wheels provide sufficient friction between the tires and road so that tire slippage does not extensively occur. The paper will present a detailed analysis of the normal reactions at the front and rear, left and right wheels and the rolling resistance forces of the tires that lead to a smaller total rolling resistance of the utility truck.

This analysis also provides a foundation, for more complex dynamical analysis of the utility truck that includes aerodynamics and established boundaries which defines the maximum reachable length of the boom equipment while maintaining safe operation of the utility truck. In this study, Altec F450 utility truck with AT200A boom equipment attached to it was used.

Keywords:  Utility truck, Morphing Boom Equipment, Terramechanics, Static Analysis, Wheel Normal Reaction, Rolling Resistance, Safe Zone.


Morphing Capabilities and Safe Operation Zone of the Utility Truck Boom Equipment

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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