Geometrical and physical simulation of Rovers using Webots software

Paper number

IAC-05-A5.2.08

Author

Mr. Nicolas Uebelhart, EiVd - Ecole d'ingénieurs du canton de Vaud, Switzerland

Year

2005

Abstract

In recent years, the planet Mars has fascinated researchers due to the fact that it may contain information about the origin of life. Following this assumption, several space missions to Mars have been organized and performed successively. The first missions sent probes to obtain data on physical characteristics of the planet. Then, Landers reached on planet Mars with in the aim of taking pictures and making analyses of the ground. Then several robots, Sojourner in 1996, Opportunity and Spirit more recently, were sent to Mars. The purpose of these robotized missions were, initially, to show the possibilities of current mobile robotics and secondly, to analyze and explore the surface of the red planet, in order to obtain data about the origins of the planet as well as of its conditions through history. 

These robotic "geologists" must be designed in such a way as to be able to move on very rugged ground and to pass over obstacles. Aptitudes for overcoming obstacles of these types of rovers can be quantified to some extent by tests carried out on Earth and from simulations carried out in a virtual environment having similar physical characteristics to Martian environment. 

Currently some powerful simulation software systems allow for the carrying out and testing of virtual models which behave very similarly to real, physical structures. Among others, one can quote the simulator of autonomous mobile robots “Webots” created by Cyberbotics Ltd (www.cyberbotics.com). 

Different structures for robots dedicated to planetary exploration, were modelled, then simulated, on Webots software. These rovers, such as the “concept E” of the RCL and its derivatives, were compared with the system rocker-bogie developed by JPL, which realized the Rover Sojourner and which currently controls the Rovers Opportunity and Spirit. The virtual world in which these robots are simulated takes into account the physical and environmental characteristics of planet Mars. That makes it possible to evaluate and compare their behaviour for overcoming obstacles on a simulated Martian ground. Obstacle models are simple (step, cylinder, sphere, slope), which makes it possible to establish standards, and makes it easier to evaluate and compare different rover frames.

Abstract document

IAC-05-A5.2.08.pdf

Manuscript document

IAC-05-A5.2.08.pdf (🔒 authorized access only).

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