Unmanned Ground Vehicles for Smart Farms

Forecasts of world population increases in the coming decades demand new production processes that are more efficient, safer, and less destructive to the environment. Industries are working to fulfill this mission by developing the smart factory concept. The agriculture world should follow industry leadership and develop approaches to implement the smart farm concept. One of the most vital elements that must be configured to meet the requirements of the new smart farms is the unmanned ground vehicles (UGV). Thus, this chapter focuses on the characteristics that the UGVs must have to function efficiently in this type of future farm. Two main approaches are discussed: automating conventional vehicles and developing specifically designed mobile platforms. The latter includes both wheeled and wheel-legged robots and an analysis of their adaptability to terrain and crops

Slide-Down Prevention for Wheeled Mobile Robots on Slopes

Wheeled mobile robots on inclined terrain can slide down due to loss of traction and gravity. This type of instability, which is different from tip-over, can provoke uncontrolled motion or get the vehicle stuck. This paper proposes slide-down prevention by real-time computation of a straightforward stability margin for a given ground-wheel friction coefficient. This margin is applied to the case study of Lazaro, a hybrid skid-steer mobile robot with caster-leg mechanism that allows tests with four or five wheel contact points. Experimental results for both ADAMS simulations and the actual vehicle demonstrate the effectiveness of the proposed approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Networked Control System for the Guidance of a Four-Wheel Steering Agricultural Robotic Platform

A current trend in the agricultural area is the development of mobile robots and autonomous vehicles for precision agriculture (PA). One of the major challenges in the design of these robots is the development of the electronic architecture for the control of the devices. In a joint project among research institutions and a private company in Brazil a multifunctional robotic platform for information acquisition in PA is being designed. This platform has as main characteristics four-wheel propulsion and independent steering, adjustable width, span of 1,80 m in height, diesel engine, hydraulic system, and a CAN-based networked control system (NCS). This paper presents a NCS solution for the platform guidance by the four-wheel hydraulic steering distributed control. The control strategy, centered on the robot manipulators control theory, is based on the difference between the desired and actual position and considering the angular speed of the wheels. The results demonstrate that the NCS was simple and efficient, providing suitable steering performance for the platform guidance. Even though the simplicity of the NCS solution developed, it also overcame some verified control challenges in the robot guidance system design such as the hydraulic system delay, nonlinearities in the steering actuators, and inertia in the steering system due the friction of different terrains

Maneuvers automation for agricultural vehicle in headland

International audienceThis paper addresses the problem of path generation and motion control for the autonomous maneuvers of agricultural vehicle in headland. A reverse turn planner is firstly presented, based on primitives connected together to easily generate the reference motion. Next, the steering and speed control algorithms are considered. To perform accurate path following, the sliding conditions are taken into account with a kinematic model extended with sliding parameters. In addition, predictive actions are developed to anticipate for vehicle steering and speed variations. The capabilities of the proposed algorithms are finally investigated through full-scale experiments. Fish-tail maneuvers are autonomously performed with an experimental mobile robot, and promising results are reported during reverse turn maneuvers with a vehicle-trailer system

Motion Control of a heterogeneous fleet of mobile robots: Formation control for achieving agriculture task

International audienceLa nécessité de réduire l'impact environnemental des activités agricoles, tout en préservant le niveau de production pour satisfaire la demande croissante des populations nécessite une étude de nouveaux outils de production. Les robots mobiles peuvent constituer une solution prometteuse, puisque les dispositifs autonomes peuvent permettre une augmentation des niveaux de production, tout en préservant l'environnement grâce à leur grande précision. Dans cet article, l'utilisation de plusieurs robots mobiles autonomes pour effectuer l'opération sur le terrain est étudiée. En particulier, les techniques prédictives sont également proposées pour tenir compte des retards induits par des actionneurs à basse altitude. Les capacités de l'approche proposée sont étudiées au moyen d'expériences de la pleine échelle. / The necessity of decreasing the environmental impact of agricultural activities, while preserving the level of production to satisfy growing population demands requires investigation of new production tools. Mobile robots may constitute a promising solution, since autonomous devices may allow increasing production levels, while preserving the environment thanks to their high accuracy. In this paper, the use of several autonomous mobile robots to perform field operation is investigated. In particular, predictive techniques are also proposed to account for delays induced by low-level actuators. Capabilities of the proposed approach are investigated through full scale experiments

Actuators and sensors for application in agricultural robots: A review

In recent years, with the rapid development of science and technology, agricultural robots have gradually begun to replace humans, to complete various agricultural operations, changing traditional agricultural production methods. Not only is the labor input reduced, but also the production efficiency can be improved, which invariably contributes to the development of smart agriculture. This paper reviews the core technologies used for agricultural robots in non-structural environments. In addition, we review the technological progress of drive systems, control strategies, end-effectors, robotic arms, environmental perception, and other related systems. This research shows that in a non-structured agricultural environment, using cameras and light detection and ranging (LiDAR), as well as ultrasonic and satellite navigation equipment, and by integrating sensing, transmission, control, and operation, different types of actuators can be innovatively designed and developed to drive the advance of agricultural robots, to meet the delicate and complex requirements of agricultural products as operational objects, such that better productivity and standardization of agriculture can be achieved. In summary, agricultural production is developing toward a data-driven, standardized, and unmanned approach, with smart agriculture supported by actuator-driven-based agricultural robots. This paper concludes with a summary of the main existing technologies and challenges in the development of actuators for applications in agricultural robots, and the outlook regarding the primary development directions of agricultural robots in the near future

Development of an inexpensive guidance system for agricultural purposes

Robotics is a rapidly growing technology and robots have pervaded into most of the industries. Robotics and automation are designed to remove the human factor from the labor intensive and monotonous work and thereby decrease the associated costs. The application of robotics to agriculture is fairly recent. Robotic applications in agriculture vary from autonomous row-guidance tractors to fruit picking robots. Similarly, soil testing and soil sampling is one area in agriculture where automation of tasks and the employment of an autonomous robot would be of great use to consultants and farmers employing site specific farming techniques. Soil testing is an important part of farming used to determine the average nutrient status in a field and to obtain a measure of nutrient availability in the field. Fertilizers and other nutrients are applied to the fields based on different soil tests. Site specific farming is greatly dependent on soil testing and can result in increased yield, reduced cost and reduced water pollution. Soil testing requires a lot of soil samples and soil sampling is a time consuming, laborious process and expensive process. Most of the consultants employing site specific techniques use ATVs to get around large fields when sampling. The development of an autonomous guidance system for an ATV to perform soil sampling would be greatly beneficial to them. Labor costs would be significantly reduced and the operators would be subjected to fewer environmental elements. The use of ATVs ensures that no extra capital is needed to buy a vehicle. The use of a small vehicle like an ATV also causes less soil compaction. A WAAS enabled Differential GPS with accuracies to within 9.84 feet was used as the position sensor. Pocket PCs are more portable than a laptop computer and are more suitable for farm conditions. Shape files were used to provide the sampling points as input to the guidance program. A guidance program was made to operate on a PDA and provide guidance instructions. A microprocessor was programmed to read the guidance instructions and actuate the different components like throttle and steering. Tests were conducted to test the accuracy and consistency of the system. The offsets of each stop point from the test point were documented and analyzed. The results indicated that the system was as accurate as the GPS used for guidance. They also indicated that a guidance system can be realized with the use of very few components and an accuracy needed for soil sampling can be achieved. Avoidance routines for obstacles within the field were indicated as future developments