A Review of Autonomous Navigation Systems in Agricultural Environments

Mobile robots operating in agricultural environments have been a significant subject for researchers. The rapid advancement in communication, sensors and computing technologies has provided important progress in the field of agricultural autonomous robot guidance systems. Automated agricultural robots save labour costs, prevent people from performing risky operations, and provide the farmer with up-to-date and precise information to assist management decisions. The research on mobile robot navigation systems in agricultural environments consists of designing suitable systems for sensing, mapping, localisation, path planning, and obstacle avoidance. The navigation algorithm must use sensory information to determine a suitable trajectory, make a decision, and move correctly within its environment without collision. In this paper, an overview of navigation systems for autonomous agricultural vehicles is presented and discussed. The key elements are navigational sensors, computational techniques, and navigation control strategies. The selection, coordination, and combination of the optimal sensors to provide the basic information for mobile robot navigation are critical processes. Powerful algorithms are used for feature extraction, data processing and fusion. For autonomous navigation, steering controllers provide an appropriate steering action to automatically drive vehicles. Navigation of mobile robots in outdoor environments such as agricultural applications is still an open problem. The design of efficient and robust sensing and control systems for agricultural mobile robots is required to overcome the difficulties due to the weather conditions, dynamic environments, unexpected obstacles, terrain nature variations and vegetation.