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

Utility trucks are the first responders in extreme climate and severe weather situations, for saving people’s lives to restoring traffic on the roads. However, such trucks can create dangerous situations on the roads, and off-road conditions, while moving, and performing tasks. Trucks equipped with large booms 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 among the wheels. Morphing capabilities of the utility trucks need to be investigated together with the vehicle-road forces in order to hold the vehicle safe on the roads. In this research paper, static analysis and range of the normal reaction at the wheel of the utility truck is performed to characterize a safe working zone of the boom equipment when the truck is in the flat and titled surface. The analysis is performed for 5-degree of freedom boom equipment with revolute and translational joints in a complex constrained space given by the truck design using 3D moment and force-vector analysis. The possible morphing configuration of the boom equipment is examined in order to define static normal reactions at the wheel-road interaction. Further, the morphing of the boom equipment is investigated to determine limiting configurations that can be reached without rolling over the truck. In this analysis, it is assumed that the wheels provide enough friction between the tires and road so that tire slippage does not extensively occur, and the utility truck is assumed as a rigid body. In this study, utility truck equipped with boom equipment is utilized in this study for numerical illustration.

Computation of the safe working zones of Planar and Spatial Parallel Manipulators

SUMMARYThis paper presents the computation of the safe working zone (SWZ) of a parallel manipulator having three degrees of freedom. The SWZ is defined as a continuous subset of the workspace, wherein the manipulator does not suffer any singularity, and is also free from the issues of link interference and physical limits on its joints. The proposed theory is illustrated via application to two parallel manipulators: a planar 3-R̲RR manipulator and a spatial manipulator, namely, MaPaMan-I. It is also shown how the analyses can be applied to any parallel manipulator having three degrees of freedom, planar or spatial.