Robotics, Automation & Control

A report discusses some modifications of the ventricular assist device (VAD), which was described in "Small Implantable Pump Would Assist Circulation of Blood" (MSC-22424), NASA Tech Briefs, Vol. 20, No. 7 (July 1996), page 86. The VAD is a surgically implantable, miniature rotary pump designed to...

A report proposes an assembly of gimbaled valve/nozzle subassemblies for use in injecting either a propellant fluid (e.g., monomethyl hydrazine) or a propellant-simulating fluid (e.g., water) into the combustion chamber of a spacecraft thruster during hot-fire or cold testing, respectively. The...

A control system that includes a single thermal source has been designed to afford precise control of the temperature of a fluid flowing in a closed-loop system. Similar control systems could make it possible to increase production levels and to reduce risks in industrial situations in which...

A report presents an overview of continuing efforts to develop an advanced propulsion system for a spacecraft that would ascend from Mars to bring samples to Earth. The system is required to be smaller and to weigh and cost less, in comparison with a conventionally designed system of equal capability. The development...

A NASA Reference Publication discusses gear technology from mathematical and historical perspectives. Following a preface containing historical and philosophical observations, the first of three chapters presents mathematical details of the theory of gearing, including recent developments...

A report presents information on an earlier work on active magnetic bearings with high-critical-temperature superconducting coils. To recapitulate, the device is a homopolar radial-type active magnetic bearing with a bias coil and control coils made of a high-critical-temperature superconductor. The report...

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...