Model development and energy management control for hybrid electric race vehicles

A Hybrid Electric Vehicle longitudinal dynamics model for the control of energy management is developed. The model is implemented using Simulink and consists of a transitional vehicle speed input parameterized by, for example, the New European Driving Cycle. It is a backward looking model in that engine and motor on/off states are determined by the controller, dependent on wheel torque requirements and output targets. The objective of the simulation is to calculate tractive effort and resistance forces to determine longitudinal net vehicle force at the road. This article addresses model development and initial investigations of its dynamic behaviour in order to establish appropriate energy management strategies for the Hybrid Electric system. In particular, All Wheel Drive, Front Wheel Drive and Rear Wheel Drive drivetrain architectures are evaluated to determine minimum fuel usage and battery state of charge. The use of a logic controller allows a reduction of simulation time and ensures accurate results for charge depletion and harvesting. Simulated fuel consumption is within 1% of actual usage

Validation of a hybrid electric vehicle dynamics model for energy management and vehicle stability control

A Simulink Hybrid Electric Vehicle dynamics model for the control of energy management and vehicle stability is developed. The model encompasses a transitional vehicle speed input parameterized by the New European Driving Cycle. Internal combustion engine torque, motor torque and varying corner radii are set to the same time constraints as the drive cycle. Lateral acceleration, yaw rate and tyre data are validated against measured car data, resulting in a simulation model that can be utilised (with modifications) as a tool to determine stability control and power deployment for front-wheel, rear-wheel or all-wheel drive hybrid vehicles. The model yields similar outputs to a driven vehicle’s normal measured responses

Feedback control-based inverse kinematics solvers for a nuclear decommissioning robot

The article develops two novel feedback control-based Inverse Kinematics (IK) solvers. They are evaluated for a dual-manipulator mobile robotic system with application to nuclear decommissioning. The first algorithm has similarities to other feedback control based solvers, and borrows ideas from the Cyclic Coordinate Decent and the Jacobian Transpose methods. This yields a particularly straightforward algorithm with tunable Proportional-Integral-Derivative (PID) gains to determine performance. The second approach utilises a discrete-time state space modelling framework to solve the IK problem. Although the second solver is more complex to implement, preliminary simulation results for the case study example, show that it can converge quicker, and has improved immunity to the kinematic singularities that can occur in Jacobian based methods

Consumption of Whole Cottonseed by White-Tailed Deer and Nontarget Species

Supplementing diets of white-tailed deer (Odocoileus virginianus) with pelleted rations is an increasingly common practice aimed at increasing deer antler size on rangelands in Texas. Feed loss to consumption by various nontarget species (e.g., raccoons [Procyon lotor] and feral pigs [Sus scrofa]) raises both ecological and economic concerns. Whole cottonseed is a feedstuff that may afford a more targeted supplemental feeding effort. Accordingly, we determined: (1) consumption rates of whole cottonseed by feral pigs and raccoons in captivity; and (2) species visitation at feed sites and preference for whole cottonseed relative to whole corn under field conditions. For experiments 1 and 2, we trapped subadult feral pigs and raccoons (n = 16 for each) and randomly assigned them to 4 feed treatments. We weighed and took blood to assess gossypol levels from both pigs and raccoons every 2 weeks for 2 months. Pigs were adept at sorting cottonseed from their feed ration in the laboratory trial. Raccoons consumed cottonseed only under severe dietary stress (i.e., diets reduced to 60% of maintenance requirements). To supplement laboratory findings we used motion-triggered video camera systems to monitor species visitation and feeding behaviors in the field. Video surveillance (125 hours of recorded events) of feeders supported our observations from laboratory trials that cottonseed was unpalatable to feral pigs and raccoons, whereas white-tailed deer consumed cottonseed readily. Given our results, we believe that whole cottonseed merits further consideration as a supplement for free-ranging deer

Study of modulation properties of tungsten based coded-aperture

The application of coded-aperture techniques for radiation imaging systems can be seen in various application fields, but the use of coded-apertures in mixed-field radiation detection in nuclear decommissioning remains largely unexplored. It is a key to understand the gamma-ray modulation properties of a tungsten based coded aperture, in order to explore the suitability of coded-apertures for mixed-field radiation detection systems. In this paper, an investigation into the gamma-ray modulation properties of a tungsten coded aperture is presented. The aperture was designed using the mathematical principles of Modified Uniformly Redundant Arrays (MURA). Due to the complexity of the design and the small size of individual cells, the aperture was built using additive manufacturing methods. The gamma-ray field was produced by 137Cs radioactive isotope at Lancaster University, UK. An organic plastic scintillator sample, which is capable of pulse shape discrimination, has been used to detect the gamma-ray field modulated by the tungsten aperture. The scintillator was energy calibrated using 137Cs and 22Na sources, before the first measurements of the modulated gamma-ray field were taken. The pulse shape discrimination performance of the scintillator was subsequently examined, using the mixed-field provided by 252Cf. In this study, each of 169 coded aperture cells were investigated by collimating the modulated gamma-ray field of 137Cs through a 25.4 mm thick lead supporting plate. The supporting plate has a single opening in the centre of the same dimensions as the single aperture cell 2.5 mm x 2.5 mm. The number of pulses detected for every aperture location were recorded in an array. The array was then used to create a two-dimensional image of the source, which was encoded through the coded aperture pattern. Finally, the image was decoded using deconvolution techniques to reveal the actual source location. Results obtained in the study indicate sufficient gamma-ray modulation properties of the aperture, despite the relatively small footprint and thickness of the coded apertur

Development of a grow-cell test facility for research into sustainable controlled-environment agriculture

The grow-cell belongs to a relatively new category of plant factory in the horticultural industry, for which the motivation is the maximization of production and the minimization of energy consumption. This article takes a systems design approach to identify the engineering requirements of a new grow-cell facility, with the prototype based on a 12 m X 2.4 m X 2.5 m shipping container. Research contributions are made in respect to: (i) the design of a novel conveyor-irrigation system for mechanical movement of plants; (ii) tuning of the artificial light source for plant growth; and (iii) investigations into the environmental conditions inside the grow-cell, including the temperature and humidity. In particular, the conveyor-irrigation and lighting systems are optimised in this article to make the proposed grow-cell more effective and sustainable. With regard to micro-climate, data are collected from a distributed sensor array to provide improved understanding of the heterogeneous conditions arising within the grow-cell, with a view to future optimisation. Preliminary growth trials demonstrate that Begonia semperflorens can be harvested to the satisfaction of a commercial grower. In future research, the prototype unit thus developed can be used to investigate production rates, plant quality and whole system operating costs

Models for heating system optimisation

Heating, Ventilation and Air Conditioning (HVAC) systems generally have high energy requirements, hence there is considerable interest in the development of modelling techniques, optimisation tools and micro-climate control algorithms for buildings. Pertinent to this research area is the Lancaster University Main Campus, for which a central energy centre supplies the hot water used to heat around 50% of the buildings. The Building Management System provides an abundance of energy data for the entire campus, which is further enhanced by the availability of data from the Hazelrigg weather station. This project concerns the development simple, flexible models suitable for improving control system robustness and overall system optimisation. Lancaster's energy centre provides multiple methods of heat production, such as gas boilers and a biomass generator. The models are being used to explore options for hierarchical control, with a focus on optimising the use of the boilers and generator. To achieve this, non-minimal state space model predictive control methods are being adapted for this application. A novelty of the research is the incorporation of weather forecasting and human occupancy data into the control calculations. The research considers the Charles Carter Building as a case study example. This building has a central atrium, surrounded by lecture theatres, offices, meeting rooms and break-out spaces

A response to “Likelihood ratio as weight of evidence: a closer look” by Lund and Iyer

Recently, Lund and Iyer (L&I) raised an argument regarding the use of likelihood ratios in court. In our view, their argument is based on a lack of understanding of the paradigm. L&I argue that the decision maker should not accept the expert’s likelihood ratio without further consideration. This is agreed by all parties. In normal practice, there is often considerable and proper exploration in court of the basis for any probabilistic statement. We conclude that L&I argue against a practice that does not exist and which no one advocates. Further we conclude that the most informative summary of evidential weight is the likelihood ratio. We state that this is the summary that should be presented to a court in every scientific assessment of evidential weight with supporting information about how it was constructed and on what it was based

The Next Generation Virgo Cluster Survey. IX. Estimating the Efficiency of Galaxy Formation on the Lowest-Mass Scales

The Next Generation Virgo Cluster Survey has recently determined the luminosity function of galaxies in the core of the Virgo cluster down to unprecedented magnitude and surface brightness limits. Comparing simulations of cluster formation to the derived central stellar mass function, we attempt to estimate the stellar-to-halo-mass ratio (SHMR) for dwarf galaxies, as it would have been before they fell into the cluster. This approach ignores several details and complications, e.g., the contribution of ongoing star formation to the present-day stellar mass of cluster members, and the effects of adiabatic contraction and/or violent feedback on the subhalo and cluster potentials. The final results are startlingly simple, however; we find that the trends in the SHMR determined previously for bright galaxies appear to extend down in a scale-invariant way to the faintest objects detected in the survey. These results extend measurements of the formation efficiency of field galaxies by two decades in halo mass, or five decades in stellar mass, down to some of the least massive dwarf galaxies known, with stellar masses of $\sim 10^5 M_\odot$.Comment: 18 pages, 12 figures; published in ApJ July 1st 201