Author's personal copy Variable field-of-view machine vision based row guidance of an agricultural robot

a b s t r a c t A novel variable field-of-view machine vision method was developed allowing an agricultural robot to navigate between rows in cornfields. The machine vision hardware consisted of a camera with pitch and yaw motion control. Guidance lines were detected using an image-processing algorithm, employing morphological features in a far, near and lateral field of view, and the robot was guided along these lines using fuzzy logic control. The method was tested while the vehicle successfully traveled through a distance of 30 m towards the end of a crop row in three replications. To evaluate the guidance performance, RTK-GPS data were collected, showing a maximum guidance error of 15.8 mm and stable navigational behavior

Development of Autonomous Robots for Agricultural Applications

Abstract. Two autonomous robots were developed as platforms for crop/soil scouting and future robotic field operations. The robots have differing technological philosophies. AgBo is a flexible industrial style robot with a sophisticated steering, sensing and communication arrangement. It has independent four-wheel steering, four steering modes (including crabbing and spinning) and inclination control. A SICK laser range finder, combined with an electronic compass, was used for crop guidance. The main communication among sensors, actuators and controllers was implemented using a Controller Area Network (CAN). AgTracker, in contrast, was built with ruggedness, simplicity and low cost in mind. It features simple skid steering and an arrangement of eight low-cost infrared sensors, two ultrasonic sensors and an electronic compass were used for crop guidance. All of these functions, including Remote Control were implemented using a single microcontroller and no communication network was applied. AgTracker’s simplicity and ruggedness make it a strong candidate for a generic platform for scientists to develop autonomous crop scouts and field operation machines. This could refocus the research emphasis from the robots themselves to the

Effect of biodiesel on engine performances and emissions

As a renewable, sustainable and alternative fuel for compression ignition engines, biodiesel instead of diesel has been increasingly fueled to study its effects on engine performances and emissions in the recent 10 years. But these studies have been rarely reviewed to favor understanding and popularization for biodiesel so far. In this work, reports about biodiesel engine performances and emissions, published by highly rated journals in scientific indexes, were cited preferentially since 2000 year. From these reports, the effect of biodiesel on engine power, economy, durability and emissions including regulated and non-regulated emissions, and the corresponding effect factors are surveyed and analyzed in detail. The use of biodiesel leads to the substantial reduction in PM, HC and CO emissions accompanying with the imperceptible power loss, the increase in fuel consumption and the increase in NOx emission on conventional diesel engines with no or fewer modification. And it favors to reduce carbon deposit and wear of the key engine parts. Therefore, the blends of biodiesel with small content in place of petroleum diesel can help in controlling air pollution and easing the pressure on scarce resources without significantly sacrificing engine power and economy. However, many further researches about optimization and modification on engine, low temperature performances of engine, new instrumentation and methodology for measurements, etc., should be performed when petroleum diesel is substituted completely by biodiesel.Biodiesel Diesel engine Performance Emission

Design and analysis of a wheel-legged hybrid locomotion mechanism

A wheel-legged hybrid robot was put forward. First, the mechanical design of this chassis was introduced. Second, based on the kinematic analysis, comparison between the robot with the active transition system and that with the passive transition system was made. Third, the process of overcoming three kinds of obstacles was simulated. Finally, the conclusion can be made that this hybrid locomotion mechanism with the active transition system has good performance on rough terrains

Simulation software and virtual environments for acceleration of agricultural robotics: features highlights and performance comparison

Research efforts for development of agricultural robots that can effectively perform tedious field tasks have grown significantly in the past decade. Agricultural robots are complex systems that require interdisciplinary collaborations between different research groups for effective task delivery in unstructured crops and plants environments. With the exception of milking robots, the extensive research works that have been carried out in the past two decades for adaptation of robotics in agriculture have not yielded a commercial product to date. To accelerate this pace, simulation approach and evaluation methods in virtual environments can provide an affordable and reliable framework for experimenting with different sensing and acting mechanisms in order to verify the performance functionality of the robot in dynamic scenarios. This paper reviews several professional simulators and custom-built virtual environments that have been used for agricultural robotic applications. The key features and performance efficiency of three selected simulators were also compared. A simulation case study was demonstrated to highlight some of the powerful functionalities of the Virtual Robot Experimentation Platform. Details of the objects and scenes were presented as the proof-of-concept for using a completely simulated robotic platform and sensing systems in a virtual citrus orchard. It was shown that the simulated workspace can provide a configurable and modular prototype robotic system that is capable of adapting to several field conditions and tasks through easy testing and debugging of control algorithms with zero damage risk to the real robot and to the actual equipment. This review suggests that an open-source software platform for agricultural robotics will significantly accelerate effective collaborations between different research groups for sharing existing workspaces, algorithms, and reusing the materials

Research and development in agricultural robotics: A perspective of digital farming

Digital farming is the practice of modern technologies such as sensors, robotics, and data analysis for shifting from tedious operations to continuously automated processes. This paper reviews some of the latest achievements in agricultural robotics, specifically those that are used for autonomous weed control, field scouting, and harvesting. Object identification, task planning algorithms, digitalization and optimization of sensors are highlighted as some of the facing challenges in the context of digital farming. The concepts of multi-robots, human-robot collaboration, and environment reconstruction from aerial images and ground-based sensors for the creation of virtual farms were highlighted as some of the gateways of digital farming. It was shown that one of the trends and research focuses in agricultural field robotics is towards building a swarm of small scale robots and drones that collaborate together to optimize farming inputs and reveal denied or concealed information. For the case of robotic harvesting, an autonomous framework with several simple axis manipulators can be faster and more efficient than the currently adapted professional expensive manipulators. While robots are becoming the inseparable parts of the modern farms, our conclusion is that it is not realistic to expect an entirely automated farming system in the future