Design of a walking robot

Carnegie Mellon University's Autonomous Planetary Exploration Program (APEX) is currently building the Daedalus robot; a system capable of performing extended autonomous planetary exploration missions. Extended autonomy is an important capability because the continued exploration of the Moon, Mars and other solid bodies within the solar system will probably be carried out by autonomous robotic systems. There are a number of reasons for this - the most important of which are the high cost of placing a man in space, the high risk associated with human exploration and communication delays that make teleoperation infeasible. The Daedalus robot represents an evolutionary approach to robot mechanism design and software system architecture. Daedalus incorporates key features from a number of predecessor systems. Using previously proven technologies, the Apex project endeavors to encompass all of the capabilities necessary for robust planetary exploration. The Ambler, a six-legged walking machine was developed by CMU for demonstration of technologies required for planetary exploration. In its five years of life, the Ambler project brought major breakthroughs in various areas of robotic technology. Significant progress was made in: mechanism and control, by introducing a novel gait pattern (circulating gait) and use of orthogonal legs; perception, by developing sophisticated algorithms for map building; and planning, by developing and implementing the Task Control Architecture to coordinate tasks and control complex system functions. The APEX project is the successor of the Ambler project

Martian Lava Tube Exploration Using Jumping Legged Robots: A Concept Study

In recent years, robotic exploration has become increasingly important in planetary exploration. One area of particular interest for exploration is Martian lava tubes, which have several distinct features of interest. First, it is theorized that they contain more easily accessible resources such as water ice, needed for in-situ utilization on Mars. Second, lava tubes of significant size can provide radiation and impact shelter for possible future human missions to Mars. Third, lava tubes may offer a protected and preserved view into Mars' geological and possible biological past. However, exploration of these lava tubes poses significant challenges due to their sheer size, geometric complexity, uneven terrain, steep slopes, collapsed sections, significant obstacles, and unstable surfaces. Such challenges may hinder traditional wheeled rover exploration. To overcome these challenges, legged robots and particularly jumping systems have been proposed as potential solutions. Jumping legged robots utilize legs to both walk and jump. This allows them to traverse uneven terrain and steep slopes more easily compared to wheeled or tracked systems. In the context of Martian lava tube exploration, jumping legged robots would be particularly useful due to their ability to jump over big boulders, gaps, and obstacles, as well as to descend and climb steep slopes. This would allow them to explore and map such caves, and possibly collect samples from areas that may otherwise be inaccessible. This paper presents the specifications, design, capabilities, and possible mission profiles for state-of-the-art legged robots tailored to space exploration. Additionally, it presents the design, capabilities, and possible mission profiles of a new jumping legged robot for Martian lava tube exploration that is being developed at the Norwegian University of Science and Technology.Comment: 74rd International Astronautical Congress (IAC

NeBula: TEAM CoSTAR’s robotic autonomy solution that won phase II of DARPA subterranean challenge

This paper presents and discusses algorithms, hardware, and software architecture developed by the TEAM CoSTAR (Collaborative SubTerranean Autonomous Robots), competing in the DARPA Subterranean Challenge. Specifically, it presents the techniques utilized within the Tunnel (2019) and Urban (2020) competitions, where CoSTAR achieved second and first place, respectively. We also discuss CoSTAR’s demonstrations in Martian-analog surface and subsurface (lava tubes) exploration. The paper introduces our autonomy solution, referred to as NeBula (Networked Belief-aware Perceptual Autonomy). NeBula is an uncertainty-aware framework that aims at enabling resilient and modular autonomy solutions by performing reasoning and decision making in the belief space (space of probability distributions over the robot and world states). We discuss various components of the NeBula framework, including (i) geometric and semantic environment mapping, (ii) a multi-modal positioning system, (iii) traversability analysis and local planning, (iv) global motion planning and exploration behavior, (v) risk-aware mission planning, (vi) networking and decentralized reasoning, and (vii) learning-enabled adaptation. We discuss the performance of NeBula on several robot types (e.g., wheeled, legged, flying), in various environments. We discuss the specific results and lessons learned from fielding this solution in the challenging courses of the DARPA Subterranean Challenge competition.Peer ReviewedAgha, A., Otsu, K., Morrell, B., Fan, D. D., Thakker, R., Santamaria-Navarro, A., Kim, S.-K., Bouman, A., Lei, X., Edlund, J., Ginting, M. F., Ebadi, K., Anderson, M., Pailevanian, T., Terry, E., Wolf, M., Tagliabue, A., Vaquero, T. S., Palieri, M., Tepsuporn, S., Chang, Y., Kalantari, A., Chavez, F., Lopez, B., Funabiki, N., Miles, G., Touma, T., Buscicchio, A., Tordesillas, J., Alatur, N., Nash, J., Walsh, W., Jung, S., Lee, H., Kanellakis, C., Mayo, J., Harper, S., Kaufmann, M., Dixit, A., Correa, G. J., Lee, C., Gao, J., Merewether, G., Maldonado-Contreras, J., Salhotra, G., Da Silva, M. S., Ramtoula, B., Fakoorian, S., Hatteland, A., Kim, T., Bartlett, T., Stephens, A., Kim, L., Bergh, C., Heiden, E., Lew, T., Cauligi, A., Heywood, T., Kramer, A., Leopold, H. A., Melikyan, H., Choi, H. C., Daftry, S., Toupet, O., Wee, I., Thakur, A., Feras, M., Beltrame, G., Nikolakopoulos, G., Shim, D., Carlone, L., & Burdick, JPostprint (published version

NeBula: Team CoSTAR's robotic autonomy solution that won phase II of DARPA Subterranean Challenge

This paper presents and discusses algorithms, hardware, and software architecture developed by the TEAM CoSTAR (Collaborative SubTerranean Autonomous Robots), competing in the DARPA Subterranean Challenge. Specifically, it presents the techniques utilized within the Tunnel (2019) and Urban (2020) competitions, where CoSTAR achieved second and first place, respectively. We also discuss CoSTAR¿s demonstrations in Martian-analog surface and subsurface (lava tubes) exploration. The paper introduces our autonomy solution, referred to as NeBula (Networked Belief-aware Perceptual Autonomy). NeBula is an uncertainty-aware framework that aims at enabling resilient and modular autonomy solutions by performing reasoning and decision making in the belief space (space of probability distributions over the robot and world states). We discuss various components of the NeBula framework, including (i) geometric and semantic environment mapping, (ii) a multi-modal positioning system, (iii) traversability analysis and local planning, (iv) global motion planning and exploration behavior, (v) risk-aware mission planning, (vi) networking and decentralized reasoning, and (vii) learning-enabled adaptation. We discuss the performance of NeBula on several robot types (e.g., wheeled, legged, flying), in various environments. We discuss the specific results and lessons learned from fielding this solution in the challenging courses of the DARPA Subterranean Challenge competition.The work is partially supported by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004), and Defense Advanced Research Projects Agency (DARPA)

Technologies Enabling Exploration of Skylights, Lava Tubes and Caves

Robotic exploration of skylights and caves can seek out life, investigate geology and origins, and open the subsurface of other worlds to humankind. However, exploration of these features is a daunting venture. Planetary voids present perilous terrain that requires innovative technologies for access, exploration, and modeling. This research developed technologies for venturing underground and conceived mission architectures for robotic expeditions that explore skylights, lava tubes and caves. The investigation identified effective designs for mobile robot architecture to explore sub-planetary features. Results provide insight into mission architectures, skylight reconnaissance and modeling, robot configuration and operations, and subsurface sensing and modeling. These are developed as key enablers for robotic missions to explore planetary caves. These results are compiled to generate "Spelunker", a prototype mission concept to explore a lunar skylight and cave. The Spelunker mission specifies safe landing on the rim of a skylight, tethered descent of a power and communications hub, and autonomous cave exploration by hybrid driving/hopping robots. A technology roadmap was generated identifying the maturation path for enabling technologies for this and similar missions

Corob-x: a cooperative robot team for the exploration of lunar skylights

The project CoRob-X develops and demonstrates enabling technologies for multi-agent robotic teams to explore planetary surfaces with a focus on hard-to-reach areas where a collaborative scheme is required to efficiently explore complex environments. Exploring lava tubes is such a challenging environment and requires a team of robots able to collaborate in an autonomous way to find their way to the subsurface tube system, descend through a natural entry hole (the so-called skylight), and explore the interior with payload instruments to provide scientific data. The developed robotic exploration system that will tackle the ambitious goal is composed of three rovers with substantially different technical characteristics. The paper presents the overall approach, i.e., the control architecture, the robotic systems, and the software to be used. It also showcases the selected mission phases that will be demonstrated in a field-test campaign. In addition, a terrestrial mining use case is presented that demonstrates how the developed autonomy-enabling software can be transferred to terrestrial applications.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

DESIGN OF A MINIATURISED HEXAPOD ROVER FOR MARTIAN EXPLORATION

Lo scopo di questo lavoro è la progettazione preliminare di un robot esapode miniaturizzato bio-insipired per l'esplorazione dei tubi lavici marziani, ovvero i condotti sotterranei formati dall'attività lavica di vulcani non esplosivi. A tal fine, è stata scelta una suite di sensori per la caratterizzazione di questi ambienti. Con l'obiettivo di mappare le grotte, l'esapode è stato equipaggiato con una telecamera e sono stati individuati anche una serie di sensori per misurare la presenza di perclorato, la dose di radiazioni che passa lo strato basaltico, la temperatura e l'umidità relativa all'interno dei tubi di lavici. In questo lavoro vengono spiegate anche le ragioni della scelta di questo tipo di analisi e gli strumenti individuati. La scelta dei sensori da ospitare nell'esapode ha portato ad avere le dimensioni preliminari del robot, in modo da poterne decidere la configurazione. La configurazione scelta consiste in un corpo centrale rettangolare con le sei zampe disposte simmetricamente lungo il lato più lungo; le zampe sono state progettate basandosi su quelle degli insetti. Essendo un dimensionamento iniziale, è stata utilizzata la configurazione più semplice per verificare i componenti e la possibile realizzazione. Il robot è stato riprodotto con Solidworks e poi importato in Simulink. Il capitolo principale è incentrato sulla simulazione del robot e del suo movimento attraverso l'ambiente MATLAB&Simulink, in modo da verificare la possibilità di utilizzare i servi più piccoli presenti sul mercato, attraverso il rilevamento delle coppie richieste dal rover. Il metodo della cinematica inversa è stato utilizzato per imporre una traiettoria semiellittica alle gambe attraverso script e funzioni dedicate che creano i vettori dei profili di posizione, di velocità e infine i vettori dei profili di accelerazione che sono stati impostati trapezoidali per evitare problemi dovuti a discontinuità. Sono stati testati tre tipi di andature: metacronale, ondulata e tripode, corrispondenti a tre velocità del robot. È stato possibile verificare l'uso dei servi attraverso la modellazione, in quanto sono stati rispettati i limiti imposti da questi ultimi.The purpose of this work is the preliminary design of a miniaturized bio-insipired hexapod robot for the exploration of Martian lava tubes, i.e. the underground conduits formed through the lava activity of non-explosive volcanoes. For this purpose, a suite of sensor was chosen for the characterization of these environments. With the aim of mapping the caves, the hexapod has been equipped with a camera and a series of sensors were also identified to measure the presence of perchlorate, the dose of radiation that passes the basaltic layer, the temperature and the relative humidity inside the lava tubes. In this work, the reasons for choosing this type of analysis are also explained, along with the identified instruments. The choice of sensors to accommodate in the hexapod led to have the preliminary dimensions of the robot, so that a decision could be made on the configuration. The configuration chosen consists of a rectangular central body with the six legs arranged symmetrically along the longest side, the legs were designed based on those of insects. Being an initial design, it was used the simplest configuration to verify the components and the possible realisation of it. The robot was reproduced using Solidworks and then imported in Simulink. The main chapter is focused on the simulation of the robot and its motion through the MATLAB&Simulink environment so that the possibility of using the smallest servos found on the market can be verified, through the sensing of the torques required by the rover. The inverse kinematics method was used to impose a semi-elliptical trajectory on the legs through dedicated scripts and functions that create the vectors of the position profiles, the velocity profiles and, finally, the vectors of the acceleration profiles that have been set trapezoidal to avoid problems due to discontinuities. Three types of gaits were tested: metachronal, ripple and tripod gait, corresponding to three speeds of the robot. It was possible to verify the use of servos through modelling, as the limits imposed by them were respected