Vehicle path planning for complete field coverage using genetic algorithms

In farming operations, one of the fundamental issues facing farmer is the cost of running the farm. If the equipment the farmer is using can be made more efficient, the cost of farming will be reduced. One way of making agricultural equipment more efficient is to develop automated or autonomous functions for the equipment. One of the fundamental tasks for autonomous equipment is to plan the path for the equipment to travel. This paper reports the research on the feasibility of creating an automated method of path planning for autonomous agricultural equipment. Genetic algorithms were chosen to plan the paths with a primary goal of creating an optimal path guiding the equipment to completely cover a field while avoiding all known obstacles. Two example fields were designed for evaluating the feasibility of this concept on simple problems. While simulation results verified the feasibility of this conceptual path planning method, they also indicated that further development would be required before the algorithm could actually be implemented on agricultural equipment for real-world field applications. Keywords: Automonous equipment, genetic algorithms, off-road vehicle, path planning

Vehicle path planning for complete field coverage using genetic algorithms

In farming operations, one of the fundamental issues facing farmer is the cost of running the farm. If the equipment the farmer is using can be made more efficient, the cost of farming will be reduced. One way of making agricultural equipment more efficient is to develop automated or autonomous functions for the equipment. One of the fundamental tasks for autonomous equipment is to plan the path for the equipment to travel. This paper reports the research on the feasibility of creating an automated method of path planning for autonomous agricultural equipment. Genetic algorithms were chosen to plan the paths with a primary goal of creating an optimal path guiding the equipment to completely cover a field while avoiding all known obstacles. Two example fields were designed for evaluating the feasibility of this concept on simple problems. While simulation results verified the feasibility of this conceptual path planning method, they also indicated that further development would be required before the algorithm could actually be implemented on agricultural equipment for real-world field applications. Keywords: Automonous equipment, genetic algorithms, off-road vehicle, path planning

Ensuring Success of Complex Liner Deployment Over Complete Field Development Campaign

This paper describes the innovative engineering workflow which has been used to ensure the safe deployment of deep production liners on long step-out wells of a deep offshore development field. It highlights the importance of accurate Torque & Drag modelling during planning and operations and provides details on how the use of downhole data assisted in understanding downhole conditions on the first wells, which allowed to optimize the running and setting procedure for the next wells of the field. For this methodology, a unique Torque & Drag stiff-string model was used to simulate the evolution of side-forces, tension, stretch, torque and twist along the string at every stage of the deployment and setting of the liner. Simulations were performed both during planning phase and operations. Once the well completed, downhole memory data from a logging tool was compared with simulations, which allowed to calibrate the model, better understand downhole conditions, and provide recommendations for the next runs. Using this methodology, the operator succeeded in deploying the liner to total depth, setting the hanger and packer successfully on all the wells of the field. These operations were performed with only 40 minutes of non-productive time throughout the campaign. The paper shows how correlating downhole data with Torque & Drag simulations highlighted areas of improvement and allowed to optimize the running and setting procedure of the liner. It also led the operator to gain confidence in the feasibility of such critical operations even on the more challenging wells. Detailed engineering and collaboration were key to this success. Such methodology can be applied on every well where weight transfer is a potential issue. As the industry is heading towards digitalization and automation, this case study is a prime example which demonstrates the added value of combining advanced physics-based simulations with time based downhole data.

Complete Field Guide to Dragonflies of Australia

Dragonflies and damselflies are conspicuous insects: many are large and brightly coloured. They are also valuable indicators of environmental wellbeing. A detailed knowledge of the dragonfly fauna is therefore an important basis for decisions about environmental protection and management. This comprehensive guide to the Australian dragonfly fauna covers eight families of dragonflies and 10 families of damselflies, comprising the 113 genera and 333 species found in Australia. It has been updated with newly identified species and revised family names to reflect new world consensus systematics. Stunning full-colour images and distribution maps are accompanied by identification keys for adults as well as larvae, which are often used as bait for freshwater fish. This second edition of The Complete Field Guide to Dragonflies of Australia also includes illustrations by Albert Orr, one of the most renowned dragonfly illustrators. The extraordinary diversity of dragonflies will interest entomologists and amateur naturalists alike.

The Future of Mapping – 3D Maps, the Comparison of two of the Most Used Methods in Photogrammetric Field

In the last 15 years, mapping technology has become a necessity in smart cities planning. And 2D are starting to be augmented by 3D maps. 3D Maps are already used in the cartographic field, to create a three-dimensional view of the terrain and buildings. In this paper we address the concept of 3D Maps and we compare two methods to generate such maps. In this study two 3D maps were built, one using photogrammetric 3D stereo-restitution and one using automatic extrusion from a LiDAR point cloud and a set of 2D vector polygons. Upon comparison of these maps, we have concluded that the accuracy of the two maps is very similar and it depends very much on the input data and we have observed that creating a precise 3D map in photogrammetric environment takes much longer than the one built using the LiDAR point cloud. As 3D maps become the future of mapping, there is a continuous need for more accurate and complete field data to be collected and processed. Once more detailed field data becomes available, a clear conclusion on which of the methods provide us with a more accurate 3D map could be drawn. The evolution of 3D mapping is rapidly growing together with the applications developed to use it, especially in surveying and material monitoring. The key to future development of smart cities in based on better designs and infrastructures, and 3D mapping technology is a vital instrument to assist such a development.

Applications of proportional calculus and a non-Newtonian logistic growth model

On the set of positive real numbers, multiplication, represented by ⊕, is considered as an operation associated with the notion of sum, and the operation a ⨀ b = aln(b) represents the meaning of the traditional multiplication. The triple (R+, ⊕,⨀) forms an ordered and complete field in which derivative and integration operators are defined analogously to the Differential and Integral Calculus. In this article, we present the proportional arithmetic and we construct the theory of ordinary proportional differential equations. A proportional version of Gronwall inequality, Gompertz’s function, the q-Periodic functions, proportional heat, and wave equations as well as a proportional version of Fourier’s series are presented. Furthermore, a non-Newtonian logistic growth model is proposed.

Double-soft behavior of massless closed strings interacting with any number of closed string tachyons

We calculate the simultaneous double-soft limit of two massless closed strings scattering with any number of closed string tachyons to the subleading order at the tree level. The limit factorizes the scattering amplitude into a double-soft factor multiplying the pure tachyon subamplitude, suggesting a universal double-soft theorem for the massless closed string. We confirm an existing result for the double-soft graviton in an on-shell equivalent, but different form, while also establishing the double-soft factorization behavior of the string dilaton and of the Kalb-Ramond state, as well as the mixed graviton-dilaton case. We also show that the simultaneous and consecutive double-soft theorems are consistent with each other. We furthermore provide a complete field theory diagrammatic view on our result, which enables us in particular to establish a four-point interaction vertex for two tachyons and two massless closed string states, as well as the missing in field theory of three-point interaction of two massless closed string state and one tachyon.