Kjeld Jensen

Towards an Open Software Platform for Field Robots in Precision Agriculture

Robotics in precision agriculture has the potential to improve competitiveness and increase sustainability compared to current crop production methods and has become an increasingly active area of research. Tractor guidance systems for supervised navigation and implement control have reached the market, and prototypes of field robots performing precision agriculture tasks without human intervention also exist. But research in advanced cognitive perception and behaviour that is required to enable a more efficient, reliable and safe autonomy becomes increasingly demanding due to the growing software complexity. A lack of collaboration between research groups contributes to the problem. Scientific publications describe methods and results from the work, but little field robot software is released and documented for others to use. We hypothesize that a common open software platform tailored to field robots in precision agriculture will significantly decrease development time and resources required to perform experiments due to efficient reuse of existing work across projects and robot platforms. In this work we present the FroboMind software platform and evaluate the performance when applied to precision agriculture tasks.

Hortibot: Feasibility study of a plant nursing robot performing weeding operations - part IV

Based on the development of a robotic tool carrier (Hortibot) equipped with weeding tools, a feasibility study was carried out to evaluate the viability of this innovative technology. The feasibility was demonstrated through a targeted evaluation adapted to the obtainable knowledge on the system performance in horticulture. A usage scenario was designed to set the implementation of the robotic system in a row crop of seeded bulb onions considering operational and functional constraints in organic crop, production. This usage scenario together with the technical specifications of the implemented system provided the basis for the feasibility analysis, including a comparison with a conventional weeding system. Preliminary results show that the automation of the weeding tasks within a row crop has the potential of significantly reducing the costs and still fulfill the operational requirements set forth. The potential benefits in terms of operational capabilities and economic viability have been quantified. Profitability gains ranging from 20 to 50% are achievable through targeted applications. In general, the analyses demonstrate the operational and economic feasibility of using small automated vehicles and targeted tools in specialized production settings.

Hortibot: An Accessory Kit Transforming a Slope Mower into a Robotic Tool Carrier for High-Tech Plant Nursing - Part I

Danish organic outdoor gardeners today use 50-300 hours per hectare for manual weeding. Through automatic controlling of an existing commercial machine this often heavy and cost-consuming weeding will be eliminated. At the same time, a fully-automatic registration of field activities will contribute to the efficient implementation of EU directive 178/2002 concerning traceability in the primary production and thereby enhance the food-safety in the production chain. A radio controlled slope mower, Spider ILD, is equipped with a new robotic accessory kit. This transforms it into a tool carrier (HortiBot) for high-tech plant nursing for e.g. organic grown vegetables. The HortiBot is capable of passing over several parcels with visible rows autonomously based on a with a new commercial row detection system from Eco-Dan a/s with minimum use of Global Positioning Systems (GPS). Further unskilled workers will be able to operate the basic functions of the HortiBot within one hour of training and by using a pictogram as an operational guide. Traceability in the Hortibot will be available online and in real time since all operational data will automatically be sent to an internet based database. This paper presents the solutions chosen for the HortiBot with regard to hardware mechanicalelectrical interfaces and software. Two accompanying papers at this meeting, part II and III, covers the following project related subjects: II - Application of Quality Function Deployment (QFD) Method for Horticultural Robotic Tool Carrier Design Planning; III - HortiBot: Comparison of potential present and future phytotechnologies for weed control.

The corrosion and dissolution valence of a chromated ZnFe alloy studied by CMT and EC measurements

Abstract A number of chromated Zn-Fe (0.3% Fe) samples were corrosion tested in a 3% NaCl solution of pH 5.000 by means of simultaneous corrosion measurements by titration and electrochemical measurements. In one experiment lasting 95 h the corrosion rate was constant, although the dissolution valence fell from nearly two to one, while the corrosion potential increased by some 120 mV. A reaction scheme consistent with these observations is proposed.

Towards Rule-Based Dynamic Safety Monitoring for Mobile Robots

Safety is a key challenge in robotics, in particular for mobile robots operating in an open and unpredictable environment. To address the safety challenge, various software-based approaches have been proposed, but none of them provide a clearly specified and isolated safety layer. In this paper, we propose that safety-critical concerns regarding the robot software be explicitly declared separately from the main program, in terms of externally observable properties of the software. Concretely, we use a Domain-Specific Language (DSL) to declaratively specify a set of safety-related rules that the software must obey, as well as corresponding corrective actions that trigger when rules are violated. Our prototype DSL is integrated with ROS, is shown to be capable of specifying safety-related constraints, and is experimentally demonstrated to enforce safety behaviour in existing robot software. We believe our approach could be extended to other fields to similarly simplify safety certification.

Dicotyledon Weed Quantification Algorithm for Selective Herbicide Application in Maize Crops

The stricter legislation within the European Union for the regulation of herbicides that are prone to leaching causes a greater economic burden on the agricultural industry through taxation. Owing to the increased economic burden, research in reducing herbicide usage has been prompted. High-resolution images from digital cameras support the studying of plant characteristics. These images can also be utilized to analyze shape and texture characteristics for weed identification. Instead of detecting weed patches, weed density can be estimated at a sub-patch level, through which even the identification of a single plant is possible. The aim of this study is to adapt the monocot and dicot coverage ratio vision (MoDiCoVi) algorithm to estimate dicotyledon leaf cover, perform grid spraying in real time, and present initial results in terms of potential herbicide savings in maize. The authors designed and executed an automated, large-scale field trial supported by the Armadillo autonomous tool carrier robot. The field trial consisted of 299 maize plots. Half of the plots (parcels) were planned with additional seeded weeds; the other half were planned with naturally occurring weeds. The in-situ evaluation showed that, compared to conventional broadcast spraying, the proposed method can reduce herbicide usage by 65% without measurable loss in biological effect.

Terrain Mapping and Obstacle Detection Using Gaussian Processes

In this paper we consider a probabilistic method for extracting terrain maps from a scene and use the information to detect potential navigation obstacles within it. The method uses Gaussian process regression (GPR) to predict an estimate function and its relative uncertainty. To test the new methods, we have arranged two setups: an artificial flat surface with an object in front of the sensors and an outdoor unstructured terrain. Two sensor types have been used to determine the point cloud fed to the system: a 3D laser scanner and a stereo camera pair. The results from both sensor systems show that the estimated maps follow the terrain shape, while protrusions are identified and may be isolated as potential obstacles. Representing the data with a covariance function allows a dramatic reduction of the amount of data to process, while maintaining the statistical properties of the measured and interpolated features.

A Survey of Open-Source UAV Flight Controllers and Flight Simulators

Abstract The current disruptive innovation in civilian drone (UAV) applications has led to an increased need for research and development in UAV technology. The key challenges currently being addressed are related to UAV platform properties such as functionality, reliability, fault tolerance, and endurance, which are all tightly linked to the UAV flight controller hardware and software. The lack of standardization of flight controller architectures and the use of proprietary closed-source flight controllers on many UAV platforms, however, complicates this work: solutions developed for one flight controller may be difficult to port to another without substantial extra development and testing. Using open-source flight controllers mitigates some of these challenges and enables other researchers to validate and build upon existing research. This paper presents a survey of the publicly available open-source drone platform elements that can be used for research and development. The survey covers open-source hardware, software, and simulation drone platforms and compares their main features.

FeederAnt - An autonomous mobile unit feeding outdoor pigs

Small robots and the concept of decentralized animal husbandry make it possible to renew the principles of organic agriculture. The farm animals will be able to use the same type of housing and are placed integrated with the fields. This is expected to achieve a better utilization of nutrients and a better survival rate for useful insects and micro organisms. The small fields are flexible and could fit to the variation in soil structure topography. This type of precision agriculture has the possibility of increasing biodiversity.