No abstract

Small ground robots remain limited in their locomotion capabilities, often prevented from accessing areas restricted by tall obstacles or rough terrain. This paper presents the improved design of a hybrid-locomotion robot made to address this issue. It uses wheels for ground travel and rotarywing flight for scaling obstacles and flying over rough terrain.The robot's initial design suffered from a number of issues that prevented it from functioning fully, such as overheating motors, inadequate control electronics, and insufficient landing gear. Several improvements have been made to the robot's design to correct these problems.These obstacles, and the solutions implemented in the improved design, have enabled several design principles to be formulated for miniature hybrid-locomotion robots. It is found that hybrid-locomotion vehicles utilizing rotary-wing flight are most useful when the design is optimized for ground mode performance. Collapsibility is necessary in such vehicles to reduce the impact of the helicopter rotor on the size of the ground mode. Finally, since a large number of actions are necessary to propel and transform the robot, integrating multiple functions into each mechanism can reduce the mass of the robot.

No abstract

The use of radar in automotive applications such as adaptive cruise control is limited to detecting target vehicles directly in front of the host vehicle. Vehicles around a curve on a highway and cross-traffic vehicles at an intersection cannot be detected by current radar systems. This is primarily due to the limited beam width angle of the radar. This paper examines and evaluates the novel concept of using passive roadside reflectors (PRRs) to increase the utility of the radar system. PRRs on the shoulder and the median of a road are designed which would enable the radar system to pick up cross traffic at highway intersections. Both simulations and experiments demonstrate that this concept could be effectively used for cross-traffic distance measurement. A limitation of this technology is that cross traffic cannot be detected when the radar-equipped vehicle is close to the intersection, owing to the lateral offset of the radar from the location of the PRR. However, the system is still valuable for providing future warning of cross traffic at rural intersections. A number of options are explored for the use of PRRs to improve radar measurements on highway curves. These include the use of tangential flat-plate reflectors, skewed flat-plate reflectors, and convex reflectors. Algorithms for distance measurement with each of these options are derived and evaluated through simulations. The use of skewed flat-plate reflectors is also evaluated experimentally and found to work effectively. The effective range of the radar on highway curves could be doubled by the use of the developed system.

No abstract