Microspine Gripping Mechanism for Asteroid Capture

This paper details the development and early testing of a compliant suspension for a microspine gripper device for asteroid capture or micro-gravity percussive drilling. The microspine gripper architecture is reviewed, and a proposed microspine suspension design is presented and discussed. Prototyping methods are discussed, as well as testing methods and results. A path forward is identified from the results of the testing completed thus far. Key findings include: the microspine concept has been established as a valid architecture and the compliant suspension exhibits the desired stiffness characteristics for good gripping behavior. These developments will aid in developing the capability to grasp irregularly shaped boulders in micro-gravity

Systems and Methods for Gravity-Independent Gripping and Drilling

Systems and methods for gravity independent gripping and drilling are described. The gripping device can also comprise a drill or sampling devices for drilling and/or sampling in microgravity environments, or on vertical or inverted surfaces in environments where gravity is present. A robotic system can be connected with the gripping and drilling devices via an ankle interface adapted to distribute the forces realized from the robotic system

Boulder Capture System Design Options for the Asteroid Robotic Redirect Mission Alternate Approach Trade Study

This paper presents a boulder acquisition and asteroid surface interaction electromechanical concept developed for the Asteroid Robotic Redirect Mission (ARRM) option to capture a free standing boulder on the surface of a 100 m or larger Near Earth Asteroid (NEA). It details the down select process and ranking of potential boulder capture methods, the evolution of a simple yet elegant articulating spaceframe, and ongoing risk reduction and concept refinement efforts. The capture system configuration leverages the spaceframe, heritage manipulators, and a new microspine technology to enable the ARRM boulder capture. While at the NEA it enables attenuation of terminal descent velocity, ascent to escape velocity, boulder collection and restraint. After departure from the NEA it enables, robotic inspection, sample caching, and crew Extra Vehicular Activities (EVA)

Shape memory polymer adhesive gripper for pick-and-place applications

Over the past few years, shape memory polymers (SMPs) have been extensively studied in term of their remarkable reversible dry adhesive properties and related smart adhesive applications. However, these exceptional properties of SMPs have not been exploited for pick-and-place applications, which would otherwise advance the robotic manipulation. This work explores the use of SMPs to design an adhesive gripper which pick and place target solid objects relying on reversible dry adhesion of SMP. Compared with common finger or soft grippers, the SMP adhesive gripper interacts with a single surface of a target object for pick-and-place. Furthermore, it is easy and inexpensive to manufacture and applicable to various surfaces since it involves reversible dry adhesion. In this paper, associated physical mechanisms and temperature analyses are studied and conducted. Also, the study includes manufacturing of a dual SMP and a release tip which substantially enhances the adhesion strength and considerably minimizes the releasing force. Finally, the versatility and utility of the SMP adhesive gripper are demonstrated through pick-and-place experiments

Compliant Gripping Mechanism for Anchoring and Mobility in Microgravity and Extreme Terrain

2nd Place at Denman Undergraduate Research ForumOne major limitation of previous NASA missions in exploring asteroids, comets, and planetary surfaces such as Mars has been the inability to properly navigate these terrains with conventional mobility methods. For example, the Mars Exploration Rover (MER), Opportunity, viewed stratified bedrock in a crater wall of Mars but was unable to access the samples due to its limited mobility. Traditional land rovers cannot maneuver well in extreme space environments with microgravity conditions because of the harsh terrain and very low escape velocities on smaller bodies. Land rovers are also incapable of traversing steep crater walls and cliffs, which limits the rover’s ability to reach sites of greater scientific interest. Current drawbacks of space mobility technology lead to the opportunity to develop new, unique robots that have the ability for vertical climbing and locomotion in microgravity environments. This research focuses on developing a new technology that utilizes an array of small microspine grippers to provide the required forces to latch onto various types of rock formations. These grippers would increase a robot’s ability to effectively travel in a microgravity environment and would allow rovers to climb vertical rock faces efficiently. The research objectives will be to develop, prototype, test and optimize a new concept design for a compliant mechanism microspine gripper to achieve higher load sharing capabilities with the constraints of minimizing the overall area and stresses created within the design itself. Quick design prototypes will be iteratively manufactured and tested to check for feasibility, and a final design will be optimized through the use of linear and non-linear beam bending equations. The higher load sharing capabilities of the design will ensure that the microspines will not fail to grasp rock in critical NASA missions. A unique geometry compliant mechanism design would achieve these goals. This could ultimately lead to climbing robots that would possess a greater capability of harsh terrain and microgravity exploration with increased reliability.No embargoAcademic Major: Mechanical Engineerin

Asteroid Redirect Mission Proximity Operations for Reference Target Asteroid 2008 EV5

NASA's Asteroid Redirect Mission (ARM) is composed of two segments, the Asteroid Redirect Robotic Mission (ARRM), and the Asteroid Redirect Crewed Mission (ARCM). In March of 2015, NASA selected the Robotic Boulder Capture Option1 as the baseline for the ARRM. This option will capture a multi-ton boulder, (typically 2-4 meters in size) from the surface of a large (greater than approx.100 m diameter) Near-Earth Asteroid (NEA) and return it to cis-lunar space for subsequent human exploration during the ARCM. Further human and robotic missions to the asteroidal material would also be facilitated by its return to cis-lunar space. In addition, prior to departing the asteroid, the Asteroid Redirect Vehicle (ARV) will perform a demonstration of the Enhanced Gravity Tractor (EGT) planetary defense technique2. This paper will discuss the proximity operations which have been broken into three phases: Approach and Characterization, Boulder Capture, and Planetary Defense Demonstration. Each of these phases has been analyzed for the ARRM reference target, 2008 EV5, and a detailed baseline operations concept has been developed

바퀴벌레 모사 소형 등반 플랫폼의 설계 및 제작

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부, 2016. 2. 조규진.Small mobile robots are required in rescue missions and military task. Milli-scale robots can pass a narrow gap within a collapsed building and carry out the reconnaissance mission without being detected by enemies. The issue of a small robot is that it might get stuck in obstacles that are bigger than itself. The ability to overcome obstacles is important to small robot. Climbing can make it overcome tens of times larger than itself. In this research, three principles of cockroach climbing are defined and integrated with planar mechanism. Small cockroach can rapidly climb vertical walls with a rough surface. First principle inspired by a cockroach is stable walking with an alternating tripod gait. This gait makes stable locomotion possible thanks to the support of at least three feet. Planar transmission using a single actuator is designed for alternating tripod gait. Second principle is reducing the impact during the attachment process. Cockroach use compliant foot called tarsus structure. This can reduce the amount of normal reaction force during the interaction between spines and surface. Compliant foot are modelled based on Pseudo-rigid-body model (PRBM). Hind leg is designed to reduce the pitch-back moment at the front limb without tail. Third principle is the phase overlap. Phase overlap is an overlapping of the set of feet on the ground. Cockroaches have the phase overlap during climbing at 5body-lengths/sec. Planar quick-return leg is designed to have the phase overlap during alternating tripod gait. In this research, three key principles are extracted and integrated with planar fabrication for a small climbing robot. A new method using laminating film and fabric is developed for fast prototyping as well as for high structural strength. Fabricated robot is 8.5cm long and 6g in weight. This robot can climb on three different kinds of surfaces at around 0.1body-lengths/sec. The research suggest the possibility that a new approach based on biomimetics and planar design can solve the scale issue of small mobile robots thanks to a novel and simple mechanism.Chapter 1 Introduction 1 Chapter 2 The Principles of Cockroach Climbing 4 2.1 Alternating Tripod Gait 4 2.2 Reducing the Impact of Attachment 6 2.3 Phase Overlap 7 Chapter 3 Bio-inspired Design 8 3.1 Transmission using a Single Actuator 8 3.2 Compliant Foot and Hind Leg 9 3.3 Quick-return Leg 14 Chapter 4 Results 21 4.1 Planar Fabrication 21 4.2 Experimental Results 24 Chapter 5 Conclusion 26 Bibliography 28 국문 초록 33Maste

미세돌기 표면용 그리퍼를 위한 미세 핀 배열의 내구성 향상

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부 우주항공공학전공, 2016. 2. 주종남.In this study, durability of micro-pin array fabricated using nanosecond pulsed laser beam machining is improved for wall attachment mechanism of a climbing robot. Fabrication of micro-pin array using nanosecond pulsed laser beam machining was previously studied for simply clinging on the wall. However, due to low durability of pins, tips of pins were broken after multiple uses so the broken pins were not able to get interlocked. This study suggests a new method to increase durability of pin array for continuous use while increasing the maximum interlocking force of pins. Electrochemical etching process was used for durability improvement and interlocking force increment of pin array was gained through controlling line spacing and tip radius. Maximum interlocking force of pin has increased from 176.48 mN/mm2 to 205.32 mN/mm2, and 205.32 mN/mm2 of constant and steady interlocking force could be achieved after multiple uses without damaging tip of micro-pin array.Chapter 1. Introduction 1 1.1. Study Background 1 1.2. Purpose of Research 4 Chapter 2. Methods 6 2.1. Fabrication of micro-pin array 6 2.2. Electrochemical etching 8 2.3. Interlocking force measurement system 10 Chapter 3. Results 16 3.1. Fabrication of micro-pin array 16 3.2. Electrochemical etching and Energy Dispersive Spectro scopy 19 3.3. Interlocking force test 25 Chapter 4. Discussions 27 4.1. Analysis on tip break of micro-pin array 27 4.2. Feasibility of micro-pin array on gripper 29 Chapter 5. Conclusions 33 5.1. Conclusions 33 References 35 국문초록 38Maste

Castable Bulk Metallic Glass Strain Wave Gears: Towards Decreasing the Cost of High-Performance Robotics

The use of bulk metallic glasses (BMGs) as the flexspline in strain wave gears (SWGs), also known as harmonic drives, is presented. SWGs are unique, ultra-precision gearboxes that function through the elastic flexing of a thin-walled cup, called a flexspline. The current research demonstrates that BMGs can be cast at extremely low cost relative to machining and can be implemented into SWGs as an alternative to steel. This approach may significantly reduce the cost of SWGs, enabling lower-cost robotics. The attractive properties of BMGs, such as hardness, elastic limit and yield strength, may also be suitable for extreme environment applications in spacecraft