The optimal trajectories are known analytically for only a few ground vehicles: steered cars (Dubins 1957; Reeds & Shepp 1990), and wheel-chair-like differential-drive vehicles (Balkcom & Mason 2002). This paper presents the analytical time-optimal trajectories for a kinematic model of a vehicle of a new class, shown in figure 1(a). The wheels are omniwheels; unlike regular wheels, omniwheels s...

MOST STUDIES OF the economic impact of immigration are motivated by the desire to understand how immigrants affect various dimensions of economic status in the population of the host country. This motivation explains the persistent interest in determining whether immigrants “take jobs away” from native workers, as well as the attention paid to measuring the fiscal impact that immigration inevit...

This paper presents the approach adopted by Surrey Satellite Technology Ltd (SSTL) for development of reaction wheels incorporating commercial components and the accelerated life test / qualification philosophy. The paper focuses on the mechanical development and re-qualification of reaction wheel which has flown successfully on many missions having conducted years of in orbit operation. The sc...

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...