A small prototype mobile robot is capable of (1) hopping to move rapidly or avoid obstacles and then (2) moving relatively slowly and precisely on the ground by use of wheels in the manner of previously reported exploratory robots of the "rover" type. This robot is a descendant of a more primitive hopping robot described in "Minimally Actuated Hopping Robot" (NPO-20911), NASA Tech Briefs, Vol. 26, No. 11 (November 2002), page 50. There are many potential applications for robots with hopping and wheeled-locomotion (roving) capabilities in diverse fields of endeavor, including agriculture, search-and-rescue operations, general military operations, removal or safe detonation of land mines, inspection, law enforcement, and scientific exploration on Earth and remote planets.
The combination of hopping and roving enables this robot to move rapidly over very rugged terrain, to overcome obstacles several times its height, and then to position itself precisely next to a desired target. Before a long hop, the robot aims itself in the desired hopping azimuth and at a desired takeoff angle above horizontal. The robot approaches the target through a series of hops and short driving operations utilizing the steering wheels for precise positioning.
Features of this robot include the following:
- An adaptive controlled nonlinear spring mechanism capable of delivering force of specified intensity for hopping;
- Three deployable wheels. Two in front are independently controlled for driving and steering. The third is passive and is located in the rear of the vehicle;
- An autonomous mechanism for self-righting after landing from a hop (described in more detail below);
- A digital camera for acquiring image data;
- Electronic hardware for processing acquired data, computing hopping and roving trajectories, and either wired or wireless communication with a host computer;
- Software for use in sensor-based navigation, trajectory computations, and adjustment of hopping parameters.
The robot has a mass of about 1.5 kg and a minimum volume of about 30 cm3. It can jump about 1 m high and 2 m horizontally. After landing, the robot rights itself by a combination of actuation of side panels and shifting of its center of mass. The side panels also afford protection at landing and, in future versions, will carry photovoltaic panels for charging batteries.
Once in its upright position, the robot can sit still, move by use of its wheels, or prepare for another hop. The hopping distance can be adjusted by choosing an appropriate takeoff angle and controlling the spring loading. In the present version, images from the onboard camera are sent to a remote operator, who controls the operation of the robot; in future versions, the onboard software will enable autonomous navigation by the robot.
This work was done by Edward Barlow, Nevellie Marzwell, Sawyer Fuller, Paolo Fiorini, Andy Tretton, Joel Burdick, and Steve Schell of Caltech for NASA's Jet Propulsion Laboratory.
NPO-21249
This Brief includes a Technical Support Package (TSP).
Hopping Robot With Wheels
(reference NPO21249) is currently available for download from the TSP library.
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Overview
The document outlines a technical support package for a novel hopping robot equipped with wheels, developed under the auspices of NASA and the Jet Propulsion Laboratory (JPL). The robot, which weighs approximately 1.5 kg and has a compact volume of about 30 cubic centimeters, is designed to navigate rugged terrains efficiently. It features an adaptive hopping mechanism that allows it to jump up to 1 meter high and 2 meters long, with future iterations expected to achieve jumps of 5 meters on Earth and 15 meters on Mars, enabling it to overcome obstacles up to 20 times its height.
This robot represents an advancement over previous models, combining the ability to hop for rapid movement and obstacle avoidance with the capability to move slowly and precisely on flat surfaces using deployable wheels. This dual locomotion system enhances its versatility, making it suitable for various applications, including agriculture, search-and-rescue operations, military tasks, land mine removal, inspection, law enforcement, and scientific exploration on Earth and other planets.
Key features of the robot include an adaptive controlled spring mechanism for precise thrust, on-board deployable wheels for ground mobility, an autonomous self-righting mechanism, and integrated electronics for trajectory computation and data acquisition. Additionally, it is equipped with a wireless digital camera for image capture and dedicated algorithms for navigation and trajectory adjustment.
The motivation behind developing this robot stems from the challenges faced in space exploration, where efficient movement across rugged terrain is crucial. Traditional wheeled rovers struggle with larger obstacles, necessitating a lightweight and compact robot capable of overcoming significant terrain challenges while maintaining high precision for scientific tasks.
The document emphasizes the innovative aspects of the robot, highlighting its potential to revolutionize exploration and operational capabilities in various fields. It also notes that the work was conducted under a contract with NASA, and the findings may be made available through technical briefs, showcasing the collaborative effort between government and research institutions in advancing robotic technology. Overall, this hopping robot exemplifies a significant step forward in robotic mobility and functionality, promising to enhance exploration efforts in challenging environments.
