Daniel Guggenheim School of Aerospace Engineering

Brown Bag Lunch

February 10, 12 - 1 p.m., The Guggenheim Building 442
Lunch Provided

featuring

"Force Sensing Through a Rubber Encapsulated Pressure Sensor with a Controlled Air Cavity"

a presentation by

Benjamin Leon

and

"Development of a 3D Printed Cold Gas Thruster for BioSentinel"

a presentation by

Terry Stevenson

Leon's Presentation:

Ground contact and force detection sensors are of critical technical importance in the realization of articulated legged robots capable of navigating unknown or challenging terrains. Requirements for field deployed sensors include ease of manufacture, durability, and consistency over time. Current force and contact sensors are cost prohibitive, unreliable, require training throughout time, or the sensing range is unsuitable for the application. In this talk, the development of a new force sensor meant to address the aforementioned issues on a rotorcraft robotic landing gear platform is presented. This force sensor is based on a custom elastomer dome with a tailored air cavity adhered to a barometric pressure sensor. In this presentation, a finite element model is developed, which predicts the sensor response under operation. This experimentally validated model permits extensive trade studies of the geometries and material properties focused on the development of simple design rules for this sensor. With the simple design rules and finite element model, we design, manufacture, and test these new sensors specifically for a rotorcraft robotic landing gear.

Stevenson's Presentation:

This work presents an overview of the design, fabrication, and testing of a cold gas attitude control thruster for the BioSentinel interplanetary spacecraft. The spacecraft is a 6U cubesat that will spend 18 months in interplanetary space to observe the effects of the solar radiation environment on a living biological payload. The thruster will be used to detumble BioSentinel and provide reaction wheel unloading over the lifetime of the mission. The structure of the thruster is a single piece of 3D printed material, which encompasses the propellant tanks, feed pipes, nozzles, O-ring grooves, and structural mounting points. This provides many advantages over a traditional tank structure, including reduced manufacturing cost, reduced leak risk, and more efficient use of available volume. An engineering unit has been built, tested, and delivered to NASA Ames, and the flight unit will built in the spring of this year.