Visual and Tactile-Based Terrain Analysis Using a Cylindrical Mobile Robot

Abstract

Ground autonomous mobile robots have important applications, such as reconnaissance, patrol, planetary exploration, and military applications. In order to accomplish tasks on rough terrain, control and planning methods must consider the physical characteristics of the vehicle and of its environment. Failure to understand these characteristics could lead to vehicle endangement and consequent mission failure. This paper describes recent and current work at the Politecnico of Bari in collaboration with the University of Lecce in the area of deformable terrain mobility and sensing. A cylindrical mobile robot is presented and its rolling motion on terrain is studied from a theoretical and experimental prospect. A comprehensive model is developed taking into account the interaction of the vehicle with the terrain and the related dynamic ill effects, such as rolling resistance and slip, and it is experimentally validated. An unconventional application of the vehicle serving as a tactile sensor is discussed and experimental results are presented showing the effectiveness of the cylindrical mobile robot in estimating the properties of homogeneous, deformable terrain, which in turn can be used to assess the vehicle traversability.

Torque-based Terrain Classification for Mobile Robot

“…The torque developed by the wheel is estimated by measuring the electrical current drawn by the wheel drive motor [16,17]. It is known that in DC brushed motors, the electrical current, I, is roughly proportional to the delivered mechanical torque Tr [18].…”

Terrain assessment for precision agriculture using vehicle dynamic modelling

“…The coefficient of motion resistance can serve as the first contact feature to discriminate a certain terrain. It can be indirectly estimated through the measurement of the electrical current I that is known to be roughly proportional to the mechanical torque T r in a DC brushed motor (Reina, Foglia, Milella & Gentile, 2006;Reina, Ojeda, Milella & Borenstein, 2006) T r = τ k t I (10) k t being the motor torque constant and τ the gearhead ratio (refer to Table 1 for more details). Therefore, the coefficient of motion resistance f r can be eventually expressed as a function of I and…”

Co-Simulation and Control of a Single-Wheel Pendulum Mobile Robot

“…Currently, mobile robots address still a great interest for new and enhanced solutions regarding different topics: locomotion, perception, control system, and navigation [1][2][3]. To reduce the size and the required space for operating mobile robots, different solutions for single-wheel robots have been proposed, i.e., single spherical wheel mobile robots or ballbots [4][5][6], spherical robots [7][8][9], and single-wheel or unicycle robots [10][11][12][13][14][15][16][17]. Single-wheel robots have compact sizes, and they are more flexible than other wheeled robots because they can achieve zero rotation radius since there is only one point of contact with the surface.…”