A report describes a rover-type robotic wheeled vehicle recently built for use as a testbed for development of software for future rover-type vehicles. This vehicle is a derivative of the Field Integrated Design and Operations (FIDO) rover, which is a prototype Mars- exploration rover that also serves as a terrestrial testbed.
The present vehicle was designed to be nearly functionally identical to the FIDO rover but to be built at much lower cost and to incorporate several improvements to increase utility for development work. Accordingly, considerable effort was made to use commercial off-the-shelf parts and other parts that could be fabricated easily and at low cost. Important features of this vehicle include six-wheel drive and six-wheel steering; onboard computer and power, control, and data-communication electronics having flexibility needed for development of software; significantly increased maximum speed (60 cm/s versus 6 cm/s for the FIDO rover); a rocker-bogey suspension with external differential link, functionally equivalent to that of the FIDO rover; and a hand-held remote controller that can be used to control vehicle motion manually without using the computer (or while waiting for the onboard computer to boot up).
This work was done by Herman Herman and Reid Simmons of Carnegie Mellon University and Richard D. Petras of Caltech for NASA's Jet Propulsion Laboratory.
NPO-45645
This Brief includes a Technical Support Package (TSP).
FIDO-Class Development Rover
(reference NPO-45645) is currently available for download from the TSP library.
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Overview
The document provides a comprehensive overview of the Sparky Rover, a high-performance, low-cost rover developed through a collaboration between NASA's Jet Propulsion Laboratory (JPL) and Carnegie Mellon University (CMU). Designed as a test bed for rover technology, Sparky is functionally comparable to JPL's FIDO-class rovers, offering capabilities in natural terrain mobility and sensing modalities at a fraction of the cost.
Sparky features a robust mechanical design with six independently driven wheels, allowing for advanced maneuverability, including 4 or 6 wheel steering, which enables the rover to turn in place and perform crabbing movements. It is equipped with a powerful wheel torque that allows it to scale slopes of up to 30 degrees and overcome obstacles up to one wheel diameter high, although performance is limited by wheel traction. The rover can achieve a maximum speed of 60 cm/s, significantly faster than the FIDO's 6 cm/s.
The rover's suspension system employs a rocker/bogey design with an external differential, providing a range of motion similar to that of FIDO or the Mars Science Laboratory (MSL). It has a ground clearance of approximately 10 inches, which is about 1.25 times the diameter of its 8-inch wheels. The design includes multiple mounting points for cameras, sensors, and other equipment, enhancing its versatility for various missions.
Sparky's avionics are powered by a Core Duo 2.0 GHz mini-ITX CPU with 2GB of RAM and a 4GB solid-state flash drive running a Linux 2.6 kernel. The control panel features multiple connectivity options, including USB and Firewire, and displays real-time battery voltage and current consumption. The rover's power subsystem is designed for extended operational time, allowing for hot-swapping of the primary battery pack.
The document also highlights the rover's pose estimation capabilities, which utilize inputs from wheel speed, steering angle, a 6-DOF MEMS-based IMU, and WAAS GPS, although GPS is primarily for ground truth in experimental settings. The overall design emphasizes weatherproofing and ease of maintenance, making Sparky a valuable platform for developing and testing rover technology algorithms and software.
In summary, the Sparky Rover represents a significant advancement in low-cost rover technology, providing a versatile platform for research and development in robotic exploration.
