Motion Control/​Automation

Ceramic hybrid electromechanical systems (CHEMS) have been proposed to overcome some of the disadvantages while retaining most of the advantages of microelectromechanical systems (MEMS). Whereas MEMS are fabricated mostly by micromachining of silicon and have typical feature sizes of the order of microns or...

A report discusses the design and testing of a laboratory-model arc-jet thruster designed to operate at a nominal power level of 300 W. This thruster is an intermediate product of continuing efforts to develop smaller, lower-power, higher-specific-impulse thrusters for use in a forthcoming generation of small...

A report describes experiments on the concept described in "Real-Time Collision Avoidance for a Robot Arm" (NPO-19861), NASA Tech Briefs, Vol. 20, No. 12 (December 1996), page 98. Under this concept, collision-avoidance software processes data computed by model-based obstacle-detection software...

Two reports present updated information on a robotic system that extends the dexterity of a microsurgeon. The system was described in two articles in NASA Tech Briefs, Vol. 21, No. 10 (October 1997); namely, "Telerobot Control for Microsurgery" (NPO-19823), on page 46 and "Force-Feedback Device for...

A report describes a small, lightweight sorption compressor that is now undergoing development for use in collecting CO2 from the atmosphere on Mars. This compressor would be part of a system that would use the CO2 to generate oxygen and a carbon-based fuel for a spacecraft to return...

A brief report presents drawings for the conceptual design of a spacecraft that would land on Mars or another remote planet. The spacecraft would have a tetrahedral shape, would include airbags to cushion impact, and would have a self-righting capability. The drawings show the general appearance of the spacecraft and show the outlines...

The rectangular-cross-section blades of a centrifugal secondary impeller in a ventricular-assist blood pump would be replaced with blades of wavy cross section, according to a proposal. As explained below, the resulting modification in the flow pattern would reduce the tendency toward...