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

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

Journal of Field Robotics ◽

10.1002/rob.21449 ◽

2013 ◽

Vol 30 (3) ◽

pp. 349-370 ◽

Cited By ~ 3

Author(s):

Yasuhiro Fukuoka ◽

Katsuyuki Hoshi ◽

Ryosuke Kurosawa

Keyword(s):

Unmanned Ground Vehicle ◽

Ground Vehicle ◽

Uneven Terrain

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Mobile Robot Decision-Making Based on Offline Simulation for Navigation over Uneven Terrain

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2018.p0671 ◽

2018 ◽

Vol 30 (4) ◽

pp. 671-682

Author(s):

Yuichi Kobayashi ◽

Masato Kondo ◽

Yuji Hiramatsu ◽

Hokuto Fujii ◽

Tsuyoshi Kamiya ◽

...

Keyword(s):

Mobile Robot ◽

Path Selection ◽

Outdoor Environment ◽

Selection Strategy ◽

Unmanned Ground Vehicle ◽

Ground Vehicle ◽

Uneven Terrain ◽

Simulated Environment ◽

Terrain Features ◽

Selection Of

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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Design of a UGV Powered by Solar Energy for Precision Agriculture

Robotics ◽

10.3390/robotics9010013 ◽

2020 ◽

Vol 9 (1) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Giuseppe Quaglia ◽

Carmen Visconte ◽

Leonardo Sabatino Scimmi ◽

Matteo Melchiorre ◽

Paride Cavallone ◽

...

Keyword(s):

Precision Agriculture ◽

Degrees Of Freedom ◽

Automated System ◽

Unmanned Ground Vehicle ◽

Solar Panels ◽

Ground Vehicle ◽

Vision Sensors ◽

Landing Platform ◽

Physical Prototype ◽

Aerial Vehicle

In this paper, a novel UGV (unmanned ground vehicle) for precision agriculture, named “Agri.q,” is presented. The Agri.q has a multiple degrees of freedom positioning mechanism and it is equipped with a robotic arm and vision sensors, which allow to challenge irregular terrains and to perform precision field operations with perception. In particular, the integration of a 7 DOFs (degrees of freedom) manipulator and a mobile frame results in a reconfigurable workspace, which opens to samples collection and inspection in non-structured environments. Moreover, Agri.q mounts an orientable landing platform for drones which is made of solar panels, enabling multi-robot strategies and solar power storage, with a view to sustainable energy. In fact, the device will assume a central role in a more complex automated system for agriculture, that includes the use of UAV (unmanned aerial vehicle) and UGV for coordinated field monitoring and servicing. The electronics of the device is also discussed, since Agri.q should be ready to send-receive data to move autonomously or to be remotely controlled by means of dedicated processing units and transmitter-receiver modules. This paper collects all these elements and shows the advances of the previous works, describing the design process of the mechatronic system and showing the realization phase, whose outcome is the physical prototype.

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