A Cam-Controlled, Single Actuator-Driven Leg Mechanism for Legged Vehicles

Leg design is crucial to the performance of a legged vehicle. To achieve good walking efficiency, a leg should be able to generate a horizontal straight line by a single actuator in the walking phase. In the return phase, additional actuator(s) is used to lift and place the foot. In this paper, a study of a cam-controlled, single-actuator-driven leg is presented. It does not require additional actuator for the return motion. In addition, the legs are driven by continuous, constant speed rotary input and they move in a constant speed. Therefore, it is conceivable that the legged vehicle can be driven by a traditional rotary engine. The cam curve is designed to have connectivity of third derivative (jerk). The driving torque is analyzed. The gait and stability related to such leg mechanism are discussed. This leg mechanism has the potential to be the leg of a practical and affordable walking machine.

MAGNETIC UPWARD CONTINUATION FROM AN UNEVEN TRACK

A new method for continuing two‐dimensional potential data upward from an uneven track is developed with special emphasis on solving a particular practical problem, that of magnetic data taken near the bottom of the ocean. The method is based on the use of the Schwarz‐Christoffel transformation, which maps the original, irregular track into a horizontal straight line. It has been found to be very fast computationally and to suffer none of the restrictions found in some earlier two‐dimensional algorithms.

Orthobaric data of certain pure liquids in the neighborhood of the critical point

The orthobaric densities of liquid and vapor, and the vapor pressure, have been determined for the three pure liquids, acetone, chloroform, and benzene. It is shown that the nose of the curve, representing orthobaric densities (or volumes) as a function of temperature, though very flat, is probably not a horizontal straight line. Nevertheless, critical phenomena can be observed over a range of total volume, at the critical temperature.