Negotiating Uneven Terrain with a Compliant Designed Unmanned Ground Vehicle Equipped with Locomotive Master-Slave Operation

This paper presents an action decision framework for an autonomous mobile robot or an unmanned ground vehicle (UGV) to navigate an unknown environment. It is difficult for a UGV without global map information to decide which path to travel when it comes to a fork. However, locally observed terrain features can enable the UGV if it can utilize its past experience. The proposed path selection method utilizes correlations between features of the local terrain obtained by its laser range finder and the values of paths obtained through offline simulation using global path planning. During navigation, the UGV estimates the values of each path at a fork based on the correlation between the terrain feature and the value. It was confirmed that the proposed method allows the selection of paths that are more effective compared with a simple path selection strategy with which the UGV selects the closer path to the goal. The proposed method was evaluated in both a simulated environment and a real outdoor environment.

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Negotiating Uneven Terrain by a Simple Teleoperated Tracked Vehicle with Internally Movable Center of Gravity

Applied Sciences ◽

10.3390/app12010525 ◽

2022 ◽

Vol 12 (1) ◽

pp. 525

Author(s):

Yasuhiro Fukuoka ◽

Kazuyuki Oshino ◽

Ahmad Najmuddin Ibrahim

Keyword(s):

Mechanical Design ◽

Center Of Gravity ◽

The Body ◽

Unmanned Ground Vehicle ◽

Tracked Vehicle ◽

Ground Vehicle ◽

High Position ◽

Uneven Terrain ◽

Dc Motors ◽

Mass Position

We propose a mechanical design for a simple teleoperated unmanned ground vehicle (UGV) to negotiate uneven terrain. UGVs are typically classified into legged, legged-wheeled, wheeled, and tanked forms. Legged vehicles can significantly shift their center of gravity (COG) by positioning their multi-articulated legs at appropriate trajectories, stepping over a high obstacle. To realize a COG movable mechanism with a small number of joints, a number of UGVs have been developed that can shift their COG by moving a mass at a high position above the body. However, these tend to pose a risk of overturning, and the mass must be moved quite far to climb a high step. To address these issues, we design a novel COG shift mechanism, in which the COG can be shifted forward and backward inside the body by moving most of its internal devices. Since this movable mass includes DC motors for driving both tracks, we can extend the range of the COG movement. We demonstrate that a conventional tracked vehicle prototype can traverse a step and a gap between two steps, as well as climb stairs and a steep slope, with a human operating the vehicle movement and the movable mass position.

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Obstacle Detection for Unmanned Ground Vehicle on Uneven Terrain

The Transactions of The Korean Institute of Electrical Engineers ◽

10.5370/kiee.2016.65.2.342 ◽

2016 ◽

Vol 65 (2) ◽

pp. 342-348 ◽

Cited By ~ 1

Author(s):

Tok Son Choe ◽

Sang Hyun Joo ◽

Yong Woon Park ◽

Jin Bae Park

Keyword(s):

Obstacle Detection ◽

Unmanned Ground Vehicle ◽

Ground Vehicle ◽

Uneven Terrain

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Design of a Mechanism with Embedded Suspension to Reconfigure the Agri_q Locomotion Layout

Robotics ◽

10.3390/robotics10010015 ◽

2021 ◽

Vol 10 (1) ◽

pp. 15

Author(s):

Carmen Visconte ◽

Paride Cavallone ◽

Luca Carbonari ◽

Andrea Botta ◽

Giuseppe Quaglia

Keyword(s):

Precision Agriculture ◽

Ground Contact ◽

Unmanned Ground Vehicle ◽

Kinematic Synthesis ◽

Ground Vehicle ◽

Uneven Terrain ◽

Contact Points ◽

Curved Trajectories ◽

Wide Contact ◽

Driving Torque

The Agri_q is an electric unmanned ground vehicle specifically designed for precision agriculture applications. Since it is expected to traverse on unstructured terrain, especially uneven terrain, or to climb obstacles or slopes, an eight-wheeled locomotion layout, with each pair of wheels supported by a bogie, has been chosen. The wide contact surface between the vehicle and the ground ensures a convenient weight distribution; furthermore, the bogie acts like a filter with respect to ground irregularities, reducing the transmissibility of the oscillations. Nevertheless, this locomotion layout entails a substantial lateral slithering along curved trajectories, which results in an increase of the needed driving torque. Therefore, reducing the number of ground contact points to compare the torque adsorption in different configurations, namely four, six, or eight wheels, could be of interest. This paper presents a reconfiguration mechanism able to modify the Agri_q locomotion layout by lifting one of the two wheels carried by the bogie and to activate, at the same time, a suspension device. The kinematic synthesis of the mechanism and the dynamic characteristics of the Agri_q suspended front module are presented.

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