We propose a proof-of-concept prototype wheelchair with legs for people with motor disabilities with the objective of demonstrating the feasibility of a completely new approach to mobility. Our prototype system is a vehicle equipped with powered wheels and legs and is capable of traversing uneven terrain and circumventing obstacles such as steps and ditches. The design combines the advantages o...

The tangential contact forces that arise at the interface between the wheel of a railway vehicle and the rail provide all the traction, braking, and guidance required by the vehicle. These forces are the result of microslip or creepage and can become unstable exciting vibration of the wheel, particularly at frequencies corresponding to the wheel’s axial (and radial) modes. Although theories exi...

Much research on two-wheeled robots has been completed in the past decade, but robot stability in low-traction environments has not yet been considered. A model for the two-wheeled robot including wheel slip effects is derived. A wheel slip dependent friction model is used to simulate two low-traction surfaces: the first has characteristics similar to ice and the second is frictionless, in addi...

An efastic half-plane containing a su~ace-b~ak~og crack normal to the free surface, subjected to loading by uniform tractions over a given length af its surface, is considered. The tractions consist of pressure, constant in time, and a shear load, varying sinu~idaily in time, both applied adjacent to the crack. This geometry approximates the classical fretting problem with a resulting fatigue c...

An investigation of tires behaviour on winter roads was always a high importance in the context road safety. This paper presents experimental tire performance slush that is identified as two mixtures: mixture snow and water, crushed ice water. The measurements longitudinal lateral including traction, braking cornering were performed. Tire traction tests performed for both mixtures with differen...

The series Hybrid-Electric Drive (HED) architecture brings a significant range of potential benefits to military ground platforms. Electric-drive wheeled vehicles can feature electric traction motors in a conventional driveline, but also offer potential for motor incorporation into the axle or the wheel hub. The implementation of in-wheel hub drives presents challenges both in their design and ...

The application of fuzzy-based control strategies has recently gained enormous recognition as an approach for the rapid development of effective controllers for nonlinear time-variant systems. This paper describes the preliminary research and implementation of a fuzzy logic based controller to control the wheel slip for electric vehicle antilock braking systems (ABSs). As the dynamics of the br...

We propose a fourth-order staggered-grid finite-difference method to study dynamic faulting in three dimensions. The method uses an implementation of the boundary conditions on the fault that allows the use of general friction models including slip weakening and rate dependence. Because the staggered-grid method defines stresses and particle velocities at different grid points, we preserve symm...