Smallsat attitude control and energy storage

The small thruster mount, roughly the size of a doughnut, controls the rotation and tilt of a directional system to a high degree of accuracy (0.02 degrees). NASA developed the rotary tilting gimbal (RTG) for thruster directional control of CubeSats. This RTG is designed to provide precision control in both the tilting and rotary degree of freedom by using accurate positioning, encoded piezoelectric motors, and a close tolerance machined structure. The RTG functions via rotary motion of the integrated assembly by a grounded piezoelectric support motor, and tilts via a rotary motor that rides on the primary structure. This alleviates the need for more traditional, directional control hardware, including magnetorquers and magnetometers. The subject technology has a resulting rotational degree of freedom of 360 degrees and a tilting degree of freedom of +/- 12 degrees. The rotary motor is connected to the tilt plate by a two-piece crank assembly. The gimbal weight, including the motors, is about 420 grams; without motors, it is about 100 grams. The operating temperature range is 0-50C. Sinusoidal testing was performed before and after the random vibration tests to determine if any structural changes occurred as a result of the tests. The gimbal met the qualification requirements and did not present any significant structural changes from flight-level testing.

Since NASAs Apollo program of the late 1960s and 1970s, many previous LTV hand controllers (e.g., joysticks, T-handles) were developed and utilized albeit with shortcomings. Some of these options yielded the desired level of control but were too physically taxing to use for long periods of time in a spacesuit environment. Others simply did not offer the necessary fine motor control. Thus, there has been a long-standing need for controllers that improve upon both of these limitations. The Tri-Rotor is a novel hand controller designed to reduce operator fatigue, add control capabilities (beyond those of a joystick), and increase the fidelity of control inputs. The design consists of two slotted handles that rotate independently within opposite sides of the Tri-Rotor main-body. Each handle is programmable and can rotate 45 degrees. In this iteration, the right handle rotates counterclockwise and acts as an accelerator and brake. The left handle rotates both clockwise and counterclockwise and controls crabbing whereby the vehicles rear wheels turn in the same direction as the front wheels facilitating diagonal or possibly lateral movement. The main-body of the Tri-Rotor rotates upon a central pivot like an automotive steering wheel and can provide directional input for Ackermann-like steering. The handles on the Tri-Rotor are designed with spacesuit kinematics in mind and are operated using the pronated and supinated motions of the astronauts hands allowed by the wrist bearings between the glove and the forearm of the spacesuit. The devices central steering pivot is also operated by the hands and is leveraged by the up and down motions of the arms allowed by the constant volume joints in the spacesuits shoulders. This hand controller design staves off operator fatigue and sheds the need for separate fine-dexterity controls without sacrificing precision. The Tri-Rotor Hand Controller has a technology readiness level (TRL) 5 (component and/or breadboard validation in relevant environment) and is now available for patent licensing. Please note that NASA does not manufacture products itself for commercial sale.

NASA is currently developing the next generation space suit for future missions, including the optimization of space suit gloves. When non-assisted space suit gloves are coupled to a pressurized suit and operated in a vacuum, they tend to limit the range of motion of an astronaut's hand to as little as 20% of normal range. Many of NASA's future missions will be in challenging environments where an astronauts hand dexterity will be critical for the success of NASA missions. Innovators at JSC have improved the performance on the second-generation, robotically assisted SSRG, to reduce exertion and improve the hand strength and dexterity of an astronaut in situ. The SSRGs system detects user finger movements using string potentiometers and contact with objects using force-sensitive resistors (FSRs). FSRs are imbedded in the distal and medial phalanges, palmar side of the glove. To move a finger, an actuator pulls a tendon through a Bowden Cable system which transfers mechanical pulling force of an inner cable relative to a hollow outer cable, like the brakes on a bicycle, as seen in the Figure below. An improved controller commands the new, more powerful linear actuator to drive tendon operation while minding custom controller parameters inputted through a digital editor tool. The Space Suit RoboGlove is at TRL 6 (system/subsystem model or prototype demonstrated in a relevant environment) and it is now available for licensing. Please note that NASA does not manufacture products itself for commercial sale.

The Foot Pedal Controller enables an operator of a spacecraft, aircraft, or watercraft, or a simulation of one in a video game, to control all translational and rotational movement using two foot pedals. This novel technology allows control across all six degrees of freedom, unlike any technology on the market. The components of the technology are a support structure, a left foot pedal, a right foot pedal, and supporting electronics. The Foot Pedal Controller is intuitive, easy to learn, and has ergonomic features that accommodate and stabilize the operator's feet. A working prototype is available to demonstrate key technology features to potential licensees. The Foot Pedal Controller technology could be used in designs for the flight deck of the future, video game controls, drone operations and flight simulators. This technology can be useful in any application where it is preferred or desirable to use the feet to control motion rather than using the hands. A potential market could be foot control of equipment by people with arm or hand disabilities. A unique aspect of the innovation is the consideration of natural foot mechanics in the design and placement of the sensors and actuators to reduce operator fatigue. The axes of rotation of the Controller align with the joints of the foot so the foot moves naturally to control the movement of the craft. NASA seeks collaborations with companies interested in licensing and partnering to further develop and commercialize the technology.

The RFID-Based Rotary Position Sensor was designed for use in a hand-crank dispenser with a circular disc inside the dispenser box containing a plurality of RFID integrated circuits (ICs) around the disc's periphery. An antenna is coupled to the crank on the outside of the box, which allows a user to turn the disc and dispense items. An RFID interrogator, coupled to a processor, determines the orientation of the crank based on the RFID ICs, providing information about the rotation angle of the internal disc which can then be used to assess level of material remaining in the dispenser. This sensor can be useful for items that are too small to tag individually (e.g., pharmaceutical pills), but there are various potential applications for the sensor system including use in limit switches, position sensors, and orientation sensors. The configuration of the RFID ICs and antenna can be tailored for specific applications. For example, the system could be used in a rack-and-pinion gear system to measure the rotational or angular displacement that arises from a linear force. Furthermore, the system could be incorporated into a rotary controller to refine the rotation angle of a rotating system, like a steering systemor rotor, for example. NASA's RFID-Based Rotary Position Sensor is at a TRL 6 (system/subsystem model or prototype demonstration in a relevant environment) when used in its original application as part of a hand-crank dispenser system. For additional applications that have not been explored by NASA, the invention is at a TRL 4 (component and/or breadboard validation in a laboratory environment).