The novel application of optimization and charge blended energy management control for component downsizing within a plug-in hybrid electric vehicle

The adoption of Plug-in Hybrid Electric Vehicles (PHEVs) is widely seen as an interim solution for the decarbonization of the transport sector. Within a PHEV, determining the required energy storage capacity of the battery remains one of the primary concerns for vehicle manufacturers and system integrators. This fact is particularly pertinent since the battery constitutes the largest contributor to vehicle mass. Furthermore, the financial cost associated with the procurement, design and integration of battery systems is often cited as one of the main barriers to vehicle commercialization. The ability to integrate the optimization of the energy management control system with the sizing of key PHEV powertrain components presents a significant area of research. Contained within this paper is an optimization study in which a charge blended strategy is used to facilitate the downsizing of the electrical machine, the internal combustion engine and the high voltage battery. An improved Equivalent Consumption Method has been used to manage the optimal power split within the powertrain as the PHEV traverses a range of different drivecycles. For a target CO2 value and drivecycle, results show that this approach can yield significant downsizing opportunities, with cost reductions on the order of 2%–9% being realizable

Investigation of ventricular cerebrospinal fluid flow phase differences between the foramina of Monro and the aqueduct of Sylvius

In this paper, phase contrast magnetic resonance flow measurements of the foramina of Monro and the aqueduct of Sylvius of seven healthy volunteers are presented. Peak volume flow rates are of the order of 150 mm3/s for the aqueduct of Sylvius and for the foramina of Monro. The temporal shift between these volume flows is analyzed with a high-resolution cross-correlation scheme which reveals high subject-specific phase differences. Repeated measurements show the invariability of the phase differences over time for each volunteer. The phase differences as a fraction of one period range from -0.0537 to 0.0820. A mathematical model of the pressure dynamics is presented. The model features one lumped compartment per ventricle. The driving force of the cerebrospinal fluid is modeled through pulsating choroid plexus. The model includes variations of the distribution of the choroid plexus between the ventricles. The proposed model is able to reproduce the measured phase differences with a very small (5%) variation of the distribution of the choroid plexus between the ventricles and, therefore, supports the theory that the choroid plexus drives the cerebrospinal fluid motio

Evolutionary Optimization of Feedback Controllers for Thermoacoustic Instabilities

International audienceWe present the system identifcation and the online optimization of feedback controllers applied to combustion systems using evolutionary algorithms. The algorithm is applied to gas turbine combustors that are susceptible to thermoacoustic instabilities resulting in imperfect combustion and decreased lifetime. In order to mitigate these pressure oscillations, feedback controllers sense the pressure and command secondary fuel injectors. The controllers are optimized online with an extension of the CMA evolution strategy capable of handling noise associated with the uncertainties in the pressure measurements. The presented method is independent of the specifc noise distribution and prevents premature convergence of the evolution strategy. The proposed algorithm needs only two additional function evaluations per generation and is therefore particularly suitable for online optimization. The algorithm is experimentally verifed on a gas turbine combustor test rig. The results show that the algorithm can improve the performance of controllers online and is able to cope with a variety of time dependent operating conditions

Deltoid, triceps, or both responses improve the success rate of the interscalene catheter surgical block compared with the biceps response

Background The influence of the muscular response elicited by neurostimulation on the success rate of interscalene block using a catheter (ISC) is unknown. In this investigation, we compared the success rate of ISC placement as indicated by biceps or deltoid, triceps, or both twitches. Methods Three hundred (ASA I-II) patients presenting for elective arthroscopic rotator cuff repair were prospectively randomized to assessment by biceps (Group B) or deltoid, triceps, or both twitches (Group DT). All ISCs were placed with the aid of neurostimulation. The tip of the stimulating needle was placed after disappearance of either biceps or deltoid, triceps, or both twitches at 0.3 mA. The catheter was advanced 2-3 cm past the tip of the needle and the block was performed using 40 ml ropivacaine 0.5%. Successful block was defined as sensory block of the supraclavicular nerve and sensory and motor block involving the axillary, radial, median, and musculocutaneous nerves within 30 min. Results Success rate was 98.6% in Group DT compared with 92.5% in Group B (95% confidence interval 0.01-0.11; P<0.02). Supplemental analgesics during handling of the posterior part of the shoulder capsule were needed in two patients in Group DT and seven patients in Group B. Three patients in Group B had an incomplete radial nerve distribution anaesthesia necessitating general anaesthesia. One patient in Group B had an incomplete posterior block extension of the supraclavicular nerve. No acute or late complications were observed. Conclusions Eliciting deltoid, triceps, or both twitches was associated with a higher success rate compared with eliciting biceps twitches during continuous interscalene bloc

Variable-structure control with complementarity-inputs for a lean-burn IC engine of a series hybrid vehicle

This paper presents a robust controller for an internal combustion (IC) engine, as the first stage of a project to develop a hybrid light urban vehicle, running on ethanol in lean burn. In particular, this work focuses on the design of a sliding mode control for an IC engine of a series hybrid power train. The controller must allow for optimal speed regulation and high fuel efficiency. To attain the latter, a complementary operation mode is proposed for the system inputs. Simulation results are presented and discussed showing the viability and advantages of the control strategy employed.Postprint (author's final draft

Optimal energy management for a flywheel-assisted battery electric vehicle

Battery electric vehicles are crucial to the reduction in the dependence on fossil fuels and for moving towards a zero-emission transport system. Although battery electric vehicle technology has been rapidly improving, the limited driving range and the high cost are significant impediments to the popularity of electric vehicles. The battery is the main element which affects the range and the cost of the vehicle. The batteries can provide either high power or high energy but not both. Hybridisation of the energy source is one of the methods to improve the energy efficiency of the vehicle, which involves combining a high-energy battery with a high-power source. High-speed flywheels have attractive properties and low-cost potential which makes them excellent secondary energy storage devices to be used in hybrid and electric vehicles. They are utilised to load the battery to a level so as to protect it from peak loads and to enhance its capacity and life. The flywheel is coupled to the drive line with a continuously variable transmission. This paper presents the optimal energy management strategy for a mechanically connected flywheel-assisted battery electric vehicle powertrain. The optimisation problem is complex because of factors such as the small storage capacity of the flywheel, the kinematic constraints and the slipping of clutches. Dynamic programming is used to calculate the optimal control strategy for torque distribution during operation in real-world driving cycles. The results show significant potential for reduction in the energy consumption in extra-urban and highway cycles, while reducing the peak battery loads during all cycles. The results give a benchmark of the energy-saving potential for such a powertrain and insights into how a real suboptimal controller can be designed

Contaminanti nello zooplancton

Not availableContaminanti nello zooplancton nell\u27ambito del progetto di ricerca "Indagini su DDT e sostanze pericolose nell\u27ecosistema del Lago Maggiore"

The history of Lake Maggiore industrial pollution traced through lake sediment and long term monitoring of the biota

In Lake Maggiore large watershed (ca. 6,600 sq. km), industrial activities along the XX century led to the discharge into the lake or its tributaries of several pollutants, such as DDT, PCBs and mercury. Other pollutants, such as PAHs and flame retardants (such as PBDEs) are still reaching the lake. Analyses of some of these pollutants in lake biota were performed continuously since 1998 and form a unique time series. We used in parallel lake sediment cores to infer the history of lake contamination, and analyses of biological samples to describe the distribution of these pollutants in the lake food web and its year-to-year variability. Furthermore, analysis of the sediment of the main rivers flowing towards Lake Maggiore was used to get information on present sources of pollution. Results also show that legacy pollutants, which are no more used nor produced, still reach the lake from polluted soils located around the industrial sites, in particular during heavy rainfall. In particular, we paid special attention to Hg and to DDT and its metabolites, because of the presence of a large pollution source close to the River Toce, one of the main inlets of Lake Maggiore. Although DDT production ended in 1996, p,p\u27-DDT is still found in river sediment and in molluscs collected in Lake Maggiore, deriving probably from polluted soils. On the contrary, p,p\u27-DDE prevails in fish tissues, zooplankton and molluscs. Finally, high values of the concentration of some pollutants in the sediment of Lake Maggiore outlet (River Ticino) show that the lake does not act as a perfect sink for these compounds. Considering present day pollution, PAHs derive from diffuse sources and are found in the sediment of all tributaries, while PBDEs where found only in the sediment of two inlets, revealing the presence of active point sources

Combined design and control optimization of hybrid vehicles

Hybrid vehicles play an important role in reducing energy consumption and pollutant emissions of ground transportation. The increased mechatronic system complexity, however, results in a heavy challenge for efficient component sizing and power coordination among multiple power sources. This chapter presents a convex programming framework for the combined design and control optimization of hybrid vehicles. An instructive and straightforward case study of design and energy control optimization for a fuel cell/supercapacitor hybrid bus is delineated to demonstrate the effectiveness and the computational advantage of the convex programming methodology. Convex modeling of key components in the fuel cell/supercapactior hybrid powertrain is introduced, while a pseudo code in CVX is also provided to elucidate how to practically implement the convex optimization. The generalization, applicability, and validity of the convex optimization framework are also discussed for various powertrain configurations (i.e., series, parallel, and series-parallel), different energy storage systems (e.g., battery, supercapacitor, and dual buffer), and advanced vehicular design and controller synthesis accounting for the battery thermal and aging conditions. The proposed methodology is an efficient tool that is valuable for researchers and engineers in the area of hybrid vehicles to address realistic optimal control problems

Foam formation in lakes: a long term analysis conducted on Lake Maggiore (northern Italy)

The causes and origin of foams in lakes have been rarely object of studies, although this phenomenon may cause problems to touristic or fisheries activities and imply a possible risk to human health. The formation of foams in the aquatic environment is due to the accumulation of surfaceactive compounds (surfactants) at the air-water interface joined with the mechanic action of a forcing (such as wind or waves) able to inject gas bubbles in the upper water layer. Surfactants can be either of natural or synthetic origin. Fulvic or humic acids, lipidic, proteic or colloidal substances are examples of natural surfactants that can promote foam formation, while man-made foams are generally due to the release of phosphates from agriculture and/or to the presence of organic and inorganic detergents. A comprehensive analysis of three foam episodes in Lake Maggiore (2007, 2008 and 2010) has been undertaken to identify their origin, causes and to unravel most likely factors triggering foam formation. At this scope, a long term (2000-2013) analysis of phytoplankton biovolumes and meteorological and hydrological anomalies has been performed together with the chemical characterization of foams. Foam resulted of endogenous origin, related to phytoplankton biomass degradation. The long term analysis highlighted atypical warm temperatures and residual lake stratification in winter in two of the years of foam events, coupled with exceptional Bacillariophyceae blooms in spring. Tabellaria flocculosa mostly contributed in terms of biomass in 2007 and 2008, but not in 2010, and overall total algal biomass seemed a better predictor of the risk of foam formation. Foam events occurred from July to December, driven by atypically high windy conditions, and congruently with the time needed to degrade biomass into surfactant compounds. A co-occurrence of different factors resulted essential to generate foams, and climate changes likely contributed to enhance their occurrence in Lake Maggiore