The 3-PPPS parallel robot with U-shape Base, a 6-DOF parallel robot with simple kinematics

International audienceOne of the main problems associated with the use of 6 DOF parallel robots remains the solving of their kinematic models. This is rarely possible to analytically solve their models thereby justifying the application of numerical methods. These methods are difficult to implement in an industrial controller and can cause solution bifurcations close to singularities resulting in following an unplanned trajectory. Recently, a 3-PPPS robot with U-shaped base was introduced where an analytical kinematic model can be derived. Previously, quaternion parameters were used to represent the orientation of the mobile platform. To allow for simpler model handling, this article introduces the use of Euler angles which have a physical meaning for the users. Compact writing of the direct and inverse kinematic model is thus obtained. Using algebraic and cylindrical decomposition for the workspace, this provides a simpler representation of the largest domain without singularity around the " home " configuration

Kinematics and workspace analysis of a 3ppps parallel robot with u-shaped base

This paper presents the kinematic analysis of the 3-PPPS parallel robot with an equilateral mobile platform and a U-shape base. The proposed design and appropriate selection of parameters allow to formulate simpler direct and inverse kinematics for the manipulator under study. The parallel singularities associated with the manipulator depend only on the orientation of the end-effector, and thus depend only on the orientation of the end effector. The quaternion parameters are used to represent the aspects, i.e. the singularity free regions of the workspace. A cylindrical algebraic decomposition is used to characterize the workspace and joint space with a low number of cells. The dis-criminant variety is obtained to describe the boundaries of each cell. With these simplifications, the 3-PPPS parallel robot with proposed design can be claimed as the simplest 6 DOF robot, which further makes it useful for the industrial applications

Workspace, Joint space and Singularities of a family of Delta-Like Robot

International audienceThis paper presents the workspace, the joint space and the singularities of a family of delta-like parallel robots by using algebraic tools. The different functions of SIROPA library are introduced, which is used to induce an estimation about the complexity in representing the singularities in the workspace and the joint space. A Groebner based elimination is used to compute the singularities of the manipulator and a Cylindrical Algebraic Decomposition algorithm is used to study the workspace and the joint space. From these algebraic objects, we propose some certified three-dimensional plotting describing the shape of workspace and of the joint space which will help the engineers or researchers to decide the most suited configuration of the manipulator they should use for a given task. Also, the different parameters associated with the complexity of the serial and parallel singularities are tabulated, which further enhance the selection of the different configuration of the manipulator by comparing the complexity of the singularity equations

Proceedings of the European Conference on Agricultural Engineering AgEng2021

This proceedings book results from the AgEng2021 Agricultural Engineering Conference under auspices of the European Society of Agricultural Engineers, held in an online format based on the University of Évora, Portugal, from 4 to 8 July 2021. This book contains the full papers of a selection of abstracts that were the base for the oral presentations and posters presented at the conference. Presentations were distributed in eleven thematic areas: Artificial Intelligence, data processing and management; Automation, robotics and sensor technology; Circular Economy; Education and Rural development; Energy and bioenergy; Integrated and sustainable Farming systems; New application technologies and mechanisation; Post-harvest technologies; Smart farming / Precision agriculture; Soil, land and water engineering; Sustainable production in Farm buildings

CONTRIBUTIONS ON ADVANCED AUTOMATION FOR SELECTIVE PROTECTION TREATMENTS ON SPECIALTY CROPS

Food security and food safety are the main global objectives of today\u2019s agriculture. Within this framework, the recent growing sensibility of both policy makers and consumers for food safety themes appear to be a hopeful sign for the introduction of new strategies and technological systems in the next future\u2019s agriculture. A particularly challenging issue for current crops management is the control of plant\u2019s diseases while avoiding environmental pollution. Precision pest management techniques \u2013an emerging subset of precision agriculture suite- aim at facing this challenge by means of: i) sensing technologies for the early detection and localization of diseased areas in the canopy, and ii) variable rate technologies for the selective application of crop protection treatments on target areas. In this dissertation, two innovative methodologies for hyperspectral crop\u2019s disease detection are presented. The measurements were acquired by means of a hyperspectral camera mounted onto a robotic manipulator which allowed to compose the subsequent hyperspectral scans (1 spatial dimension x 1 spectral dimension) into an hypercube (2D spatial x 1D spectral) of the imaged plant. The first disease detection method is based on the combinatorial selection of the most significant wavelengths from the hypercube data by applying linear discriminant analysis, and the classification power of the optimal selected combination is then evaluated by applying a principal component analysis. The second method is based on a new spatial filter approach, acting along the different channels of the hypercube. The two methods of detection are applied by discussing two case studies of diseases, both on cucumber plants. A first set of experiments was conducted on plants artificially inoculated with powdery mildew. A second and more extensive set of experiments was conducted on plants infected by the cucumber green mottle mosaic virus (CGMMV), which is nowadays considered one of the most dangerous diseases for the Cucurbitaceae family. The application of the two methodologies was successful in identifying the major symptoms of the diseases considered, and specifically the spatial filtering approach enable to detect the subtle morphological modifications in the plant tissue at rather early stage of CGMMV infection. Due to the high cost and complexity of the technologies adopted in the disease detection and of precision spraying equipment, the second part of the thesis applies the classical methods of mechanization cost-analysis to investigate what are the economic thresholds, which may enable the introduction of new precision pest management technologies. To this aim, the analysis is focused on vineyard and apple orchard that represent a favourable case for introducing these kind of innovations, due to the high protection treatments costs typical for these specialty crops. Starting from the results obtained in research on precision spraying in speciality crops, the technical-economic analysis considers on three different technological levels of precision spraying equipment, associated with increasing levels of reduction of the distributed amount of pesticide. This reduction is assumed to be linked to the improved accuracy in targeting the application without affecting the biological efficiency of the treatment, and hence generating a net cost benefit for the farmer. To gain insights into evaluating this benefit is of primary interest, since the profitability of precision spraying technologies will be a major driver for their adoption in speciality crops. Therefore, this study aims at: a) assessing the total costs associated to spraying equipment at the different technological levels considered; b) evaluating weather more advanced equipment can be profitable compared to current conventional sprayers. Furthermore, this analysis was extended to a high-precision, robotic spraying platform, here considered as a perspective scenario for precision spraying technologies. For this specific case, the study aimed at assessing the maximum allowed cost for such a robotic platform, which could generate positive net benefits for the farmer thanks to the envisaged pesticide reduction

Adaptive Control

Adaptive control has been a remarkable field for industrial and academic research since 1950s. Since more and more adaptive algorithms are applied in various control applications, it is becoming very important for practical implementation. As it can be confirmed from the increasing number of conferences and journals on adaptive control topics, it is certain that the adaptive control is a significant guidance for technology development.The authors the chapters in this book are professionals in their areas and their recent research results are presented in this book which will also provide new ideas for improved performance of various control application problems

Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering

Beamed-Energy Propulsion (BEP) Study

The scope of this study was to (1) review and analyze the state-of-art in beamed-energy propulsion (BEP) by identifying potential game-changing applications, (2) formulate a roadmap of technology development, and (3) identify key near-term technology demonstrations to rapidly advance elements of BEP technology to Technology Readiness Level (TRL) 6. The two major areas of interest were launching payloads and space propulsion. More generally, the study was requested and structured to address basic mission feasibility. The attraction of beamed-energy propulsion (BEP) is the potential for high specific impulse while removing the power-generation mass. The rapid advancements in high-energy beamed-power systems and optics over the past 20 years warranted a fresh look at the technology. For launching payloads, the study concluded that using BEP to propel vehicles into space is technically feasible if a commitment to develop new technologies and large investments can be made over long periods of time. From a commercial competitive standpoint, if an advantage of beamed energy for Earth-to-orbit (ETO) is to be found, it will rest with smaller, frequently launched payloads. For space propulsion, the study concluded that using beamed energy to propel vehicles from low Earth orbit to geosynchronous Earth orbit (LEO-GEO) and into deep space is definitely feasible and showed distinct advantages and greater potential over current propulsion technologies. However, this conclusion also assumes that upfront infrastructure investments and commitments to critical technologies will be made over long periods of time. The chief issue, similar to that for payloads, is high infrastructure costs

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen