A hybrid green energy-based framework with a multi-objective optimization approach for optimal frost prevention in horticulture

In this paper, first we propose a novel hybrid renewable energy-based solution for frost prevention in horticulture applications involving active heaters. Then, we develop a multi-objective robust optimization-based formulation to optimize the distribution of a given number of active heaters in a given large-scale orchard. The objectives are to optimally heat the orchard by the proposed frost prevention system and to minimize the total length of the energy distribution pipe network (which is directly related to the installation cost and the cost of energy losses during energy transfer). Next, the resulting optimization problem is approximated using a discretization scheme. A case study is provided to give an idea of the potential savings using the proposed optimization method compared to the result from a heuristic-based design, which showed a 24.13% reduction in the total pipe length and a 54.29% increase in frost prevention

Automated guided vehicle mission reliability modelling using a combined fault tree and Petri net approach

This is an open access article published by Springer and distributed under the terms of the Creative Commons Attribution Licence, https://creativecommons.org/licenses/by/4.0/Automated guided vehicles (AGVs) are be- ing extensively used for intelligent transportation and distribution of materials in warehouses and autoproduction lines due to their attributes of high efficiency and low costs. Such vehicles travel along a predefined route to deliver desired tasks without the supervision of an operator. Much effort in this area has focused primarily on route optimisation and traffic management of these AGVs. However, the health management of these vehicles and their optimal mission configuration have received little attention. To assure their added value, taking a typical AGV transport system as an example, the capability to evaluate reliability issues in AGVs are investigated in this paper. Following a Failure Modes Effects and Criticality Analysis (FMECA), the reliability of the AGV system is analysed via Fault Tree Analysis (FTA) and the vehicles mission reliability is evaluated using the Petri net (PN) method. By performing the analysis the acceptability of failure of the mission can be analysed, and hence the service capability and potential profit of the AGV system can be reviewed and the mission altered where performance is unacceptable. The PN method could easily be extended to have the capability to deal with eet AGV mission reliability assessment