Mechanical Components

Rotary Microspine Technology

A new design improves the mobility of manportable reconnaissance robots. NASA’s Jet Propulsion Laboratory, Pasadena, California Mobility for small, man-portable reconnaissance robots in the past has been limited with regard to obstacles like curbs, stairs, and vertical walls. A previous innovation overcame these obstacles by introducing rotary microspines — sharp hooks supported by elastic elements on a wheel. In this innovation, the work has been advanced with a new microspine design that eliminates the need for elastomer materials or the inserted hook.

Posted in: Mechanical Components, Briefs

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Rotary Microspine Technology

A new design improves the mobility of man-portable reconnaissance robots. NASA’s Jet Propulsion Laboratory, Pasadena, California Mobility for small, man-portable reconnaissance robots in the past has been limited with regard to obstacles like curbs, stairs, and vertical walls. A previous innovation overcame these obstacles by introducing rotary microspines — sharp hooks supported by elastic elements on a wheel. In this innovation, the work has been advanced with a new microspine design that eliminates the need for elastomer materials or the inserted hook.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Percussive Augmenter of Rotary Drills for Operation as a Rotary-Hammer Drill

New rotary drill bits designed for percussive or ultrasonic hammering convert rotary drills/samplers into rotary-hammering drills/samplers. NASA’s Jet Propulsion Laboratory, Pasadena, California A piezoelectrically actuated percussive bit augments rotary drills to form a rotary-hammering drill/sampler. The Percussive Augmenter of Rotary Drills (PARoD) bit has two key modalities: one with vibrating free-mass and one without. In the first modality, the bit is designed to rotate the tip and transmit the impact of a free mass, while the complete bit turns as a single unit. In the second modality, the ultrasonic hammering action from the piezoelectric stack and the rotation from a commercial drill are applied directly to the drilled object. The PARoD tool includes slots to ensure that the tip of the bit does not rotate separately from the piezoelectric actuator. The bit employs electric and mechanical slip rings to transfer electric power, as well as water (for removal of cuttings and bit cooling), while freely turning the bit. The cooling plumbing can be connected to the related fixtures on heavy-duty commercial rotary drills.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Non-Collinear Valve Actuator

This device separates the actions of the pneumatic actuator and the spring. Marshall Space Flight Center, Alabama Typical large aerospace valves use pneumatic actuators with large return springs to define a normal state. These springs are exclusively in line with the pneumatic actuator, and therefore are forced to have the same stroke and forces. These typical systems use either a large helical spring or a stack of Bellville springs. Each is long to ensure that the forces at the end of stroke are large enough to move the valve to the normal position with some margin. This invention reconfigures the actuator through the use of either a drag-link four-bar system or a cam to separate these two motions. The spring is allowed to have larger loads with significantly short spring stack length. This eliminates the need for long housings, heavy springs, and thus reduces the mass of the flight system. This configuration can be used for commercial valve actuators. Although commercial actuators generally do not have weight limitations, the reduction of the massive spring could reduce the cost of the product.

Posted in: Mechanics, Mechanical Components, Briefs

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Head-Mounted Display Latency Measurement Rig

This technique can be used to characterize systems for product improvement by virtual/augmented reality display manufacturers. Langley Research Center, Hampton, Virginia The device and method are used to quantify end-to-end latency of head- or helmet-mounted display with head tracking systems in a laboratory or in situ. All commercial or custom head-mounted display systems that track the user’s head for the purpose of virtual or augmented reality applications encounter positional display errors due to system latency. A basic head-mounted display (HMD) with head-tracking system is comprised of (1) a near-to-eye display, (2) the head-tracking system, (3) one or more symbology or image sources, and (4) the display/image processor. Each element, and the communication among them, contributes a portion to the total latency. HMD system latency manifests as erroneous alignment of the virtual and real surroundings as the head is slewed, and is known to induce simulator sickness and other physiological issues. Therefore, minimal system latency is a design goal to reduce these physiological symptoms. The overall latency budget is the sum of time required to measure the dynamic head position, communicate the position to the display processor, compute the scene based on the position, integrate imagery, and render the scene to the display.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Workspace-Safe Operation of a Force- or Impedance-Controlled Robot

This technology can be used for automatic control of a robot that may come into contact with an object or operator in its workspace. Lyndon B. Johnson Space Center, Houston, Texas Precise motion control of a robot by controlling its various robotic manipulators may be organized by the required level of task specification. The levels include object-level control, which describes the ability to control the behavior of an object held in a single or a cooperative grasp of the robot; end-effector control, which is control of the various manipulators such as robotic fingers and thumbs; and joint-level control. Collectively, the various control levels achieve the required mobility, dexterity, and work task-related functionality.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Cryogenic Mixing Pump with No Moving Parts

The pump is self-priming and can efficiently pump two-phase fluid. John H. Glenn Research Center, Cleveland, Ohio Refueling spacecraft in space offers tremendous benefits for increased payload capacity and reduced launch cost, but the problem of thermal stratification in long-term storage tanks presents a key challenge. To meet this challenge, a reliable, compact, lightweight, and efficient cryogenic mixing pump was developed with no moving parts. The pump uses an innovative thermodynamic process to generate fluid jets to promote fluid mixing. This thermodynamic process eliminates moving parts to generate pumping action. Inherent to its design, the pump is self-priming and can efficiently pump two-phase fluid. The device will significantly enhance the reliability of pressure control systems for storage tanks.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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