This paper presents a wheel–terrain interaction model, which enables efficient modeling of wheeled locomotion in soft soil and numerical simulations of off-road mobile robots. This modular model is derived based on wheel kinematics and terramechanics and the main focus is on describing the stress distributions along the wheel–terrain interface and the reaction forces exerted on the wheel by the...

Background: The purpose of this study was to examine the effects of voluntary wheel running on the positive reinforcing effects of heroin in rats with an established history of drug self-administration. Methods: Rats were assigned to sedentary (no wheel) and exercise (wheel) conditions and trained to self-administer cocaine under positive reinforcement contingencies. Rats acquiring cocaine self...

BACKGROUND The purpose of this study was to examine the effects of voluntary wheel running on the positive reinforcing effects of heroin in rats with an established history of drug self-administration. METHODS Rats were assigned to sedentary (no wheel) and exercise (wheel) conditions and trained to self-administer cocaine under positive reinforcement contingencies. Rats acquiring cocaine self...

wheel-set is an important part of EMU. It directly influences the EMU operation security. In recent years, some harmful circumferential and radial defects are found in the wheel rim, which occur between the periods of two light maintenances. The comprehensive security system of wheel-set has already built in china to guarantee the EMU maintenance quality and operation security. It consists of r...

An Ackerman steering linkage for short wheelbase, four-wheel vehicles has been developed. The linkage coordinates the steering angle of each wheel through a range of 180 degrees with minimal misalignment between wheels. Control of steering angles is accomplished using a single linear actuator. Control complexity is lower compared to four-wheel systems using individually controlled steering actu...

A uni-stroke text input strategy for wheel input controls is proposed, such as the wheel controls found on the 5th generation ipod multimedia devices. The popularity of the ipod indicates that the wheel input paradigm is intuitive and usable. The proposed uni-strokes are based on circular motions that follow the contour of the wheel. Spatial mnemonics based on the shape of the alphabetic charac...

The purpose of this review is to highlight the wide array of interfaces developed so far to control wheel chairs. A preliminary study on wheel chair interfaces is presented. This is followed by various types of powered wheel chair control methods such as hand, voice, communication methods and hybrid. Wheel chair control methods for persons with reduced strength are also explained. Apart from al...

A novel approach is proposed for the modeling of rigid-wheel and soft-soil interaction to efficiently compute normal and shear stress distributions in the contact area. The authors propose a velocity field in the vicinity of the contact area based on the physical nature of the problem. Thereupon, the incremental changes to the stress field are computed by resorting to elastoplasticity theory an...

A wheel is an induced cycle C plus a vertex connected to at least three vertices of C. Trotignon [14] asked if the class of wheel-free graphs is χ-bounded, i.e. if the chromatic number of every graph with no induced copy of a wheel is bounded by a function of its maximal clique. In this paper, we prove a weaker statement: for every `, the class of graphs with no induced wheel and no induced K`,...

The analysis of indentation of rigid cylindrical wheels into frictional/cohesive soils is presented. Threeand two-dimensional numerical simulations were performed using the finite element code ABAQUS to assess the influence of soil strength parameters, dilatancy, and wheel geometry on the relationship between the indentation force and wheel sinkage. The effect of three-dimensionality in the ind...