Year: 2016
Type: dissertation
Abstract: ABSTRACT Autonomous navigation is a requirement of any planetary exploration rover moving in an environment too far from Earth for efficient communication between the rover and ground control. An important feature of this autonomy is the ability of the rover to successfully negotiate obstacles that may lie in its chosen path. To accommodate this need, planetary rovers are furnished with many actively actuated or passive degrees of freedom to influence the rover configuration, and in turn, the wheel-terrain contact forces that propel the rover forth. Analysis of these methods however, depends on the use of parameters which can only be ascertained with detailed knowledge of the geometry, and constitutive properties of the terrain. This can produce considerable difficulty for the analysis of systems operating in unknown or unfamiliar environments. In this thesis, a performance indicator know as the "effective kinetic energy of impact", is explored for use in planetary rover operations. The effective kinetic energy is an indicator of how system configuration at the onset of an impact, will affect the resulting contact and impact forces. This indicator requires no knowledge of constitutive properties of the system. The indicator is discussed and developed for use with a model of an existing planetary rover prototype. Simulations with the rover model are used to compare the effective kinetic energy indicator with a more traditional, continuous force model method of evaluating contact force, and to demonstrate the similar trend between the two where contact configuration is concerned. These simulations are validated experimentally with the physical model of the rover engaging in a series of impacts with an obstacle, where the configuration is systematically varied. The experimental results are discussed, and a direction for future work and experimental validation are considered.
Source: eScholarship@McGill (McGill)
DOI: 10.82308/1711
Author: Mac Mahon, Sadhbh
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2953337740