Intelligent Based Terrain Preview Controller for a 3-axle Vehicle

Presented at 13th International Symposium on Advanced Vehicle Control, AVEC'16; Munich 13-16/09/2016The paper presents a six-wheel half longitudinal model and the design of a dual level control architecture. The first (top) level is designed using a Sugeno fuzzy inference feedforward architecture with and without preview. The second level of controllers are locally managing each wheel for each axle. As the vehicle is moving forward the front wheels and suspension units will have less time to respond when compared to the middle and rear units, hence a preview sensor is used to compensate. The paper shows that the local active suspensions together with the Sugeno Fuzzy, (locally optimised using subtractive clustering), Feedforward control strategy is more effective and this architecture has resulted in reducing the sprung mass vertical acceleration and pitch accelerations

Kinetic energy storage using a dual braking system for unmanned parallel hybrid electric vehicle

In this paper a novel regenerative dual braking strategy is proposed for utility/goods delivery unmanned vehicles in public roads, which improves the regenerative energy capturing ability and consequently improves the fuel use of parallel hybrid power train configurations for land unmanned vehicles where the priority is not comfort but extending the range. Furthermore, the analysis takes into account the power handling ability of the electric motor and the power converters. In previous research a plethora of regenerative braking strategies is shown, for this paper the key contribution is that the vehicle electric regeneration is related to a fixed braking distance in relation to the energy storage capabilities specifically for unmanned utility type land vehicles where passenger comfort is not a concern but pedestrian safety is of critical importance. Furthermore, the vehicle’s power converter capabilities facilitate the process of extending the braking time via introducing a variable deceleration profile. The proposed approach has therefore resulted in a regenerative algorithm which improves the vehicle’s energy storage capability without considering comfort since this analysis is applicable to unmanned vehicles. The algorithm considers the distance as the key parameter, which is associated to safety, therefore it allows the braking time period to be extended thus favouring the electric motor generation process while sustaining safety. This method allows the vehicle to brake for longer periods rather than short bursts hence resulting in a more effective regeneration with reduced use of the dual (i.e. caliper/stepper motor brake system). The regeneration method and analysis is addressed in the following paper sections. The simulation results show that the proposed regenerative braking strategy has improved significantly the energy recapturing ability of the hybrid power train configuration. The paper is also supported with experimental data that verify the theoretical development and the simulation results. The two strategies developed and implemented are Constant Braking Torque (CBT) and Constant Braking Power (CBP). Both methods were limited to a fixed safety-based distance. Overall the results demonstrate that the CBT method results in better energy-based savings

Investigation of Morphology and Proton Conductivity in Proton Exchange Membranes under Variable Operating Conditions by Atomic Force Microscopy

Nafion represents the most commonly employed and well characterized proton exchange membrane (PEM) used in fuel cells, however structural models which explain its physical properties are oversimplified and incomplete. In this work we use a combination of tapping mode and conductive probe (cp) AFM to investigate the nanoscale morphology and proton conductivity of Nafion. By conducting imaging at a wide range of relative humidity, we were able to characterize Nafion from extensively dehydrated to liquid equilibrated states. Rather than an even swelling of hydrophilic clusters, we see an uneven dehydration of the surface at low hydration and a rearrangement to form a network of cylindrical inverted micelles at high water content. A statistical analysis of these features allowed us to match them with previous x-ray scattering data and develop a model of Nafion which is valid at large length scales and consistent over a wide range of water contents.Comparison of this model system to new membrane materials has allowed us to better understand the structure-property relationship in these systems. We next investigated Hyflon, a short side chain analog of Nafion and found that in contrast to Nafion it is able to swell reversibly through a dilation and contraction of hydrophilic clusters with minimal rearrangement and retain more hydrophilic character at the surface at dehydrated conditions. Investigation of new multi-acid sidechain membranes was also conducted and showed that while these membranes have excellent water retention and proton conductivity, they swell and form a continuous hydrophilic phase at the surface which may be problematic during fuel cell operation. In addition to these characterization efforts, a number of advances to the cp-AFM technique were demonstrated which allowed for the investigation of new operating conditions and the extraction of new information on electrical and mechanical properties of the membrane

Generalized dilaton-Maxwell cosmic string and wall solutions

The class of static solutions found by Gibbons and Wells for dilaton-electrodynamics in flat spacetime, which describe nontopological strings and walls that trap magnetic flux, is extended to a class of dynamical solutions supporting arbitrarily large, nondissipative traveling waves, using techniques previously applied to global and local topological defects. These solutions can then be used in conjunction with S-duality to obtain more general solitonic solutions for various axidilaton-Maxwell theories. As an example, a set of dynamical solutions is found for axion, dilaton, and Maxwell fields in low energy heterotic string theory using the SL(2,R) invariance of the equations of motion.Comment: 11 pages; to appear in Phys.Lett.

Multi-mode electric actuator dynamic modelling for missile fin control

Linear first/second order fin direct current (DC) actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX) performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviou

A review of dual-spin projectile stability

This paper gives a succinct review of dual-spinprojectile stability and some technologies relating to them. It describes how the traditional stability factors from linear projectile theory are modified to better describe a controlled dual-spin projectile. Finally, it reviews works which have investigated how different aspects of a controlled dual-spin design can affect flight stability, primarily airframe structure and canard properties. A conclusion is given, highlighting important guidelines from the enclosed discussion

Health and social care in aging population: an integrated care institution for the elderly in Greece

PURPOSE: To describe the nature of the services actually offered to the elderly in Greece by an institution of integrated care, as opposed to those that should be offered according to the relevant law, and to investigate the factors influencing the supply of those services. BACKGROUND: By the year 2020 about 20 million people will be aged 80 and over in the European Union. People of third age consist 16.9% of the total Greek population. Population aging has major implications on health services, employment and society as a whole. “Open Care Centres for the Elderly” (KAPI) is a rapidly developing and expanding institution providing integrated care for the elderly. METHODS: A questionnaire to be completed by the staff was sent to all 370 KAPI. Response rate reached 66%. For the analysis of the data multiple logistic regression analysis was performed using SPSS 10.0. RESULTS: Both medical and social care is provided by the KAPI to the elderly with different magnitude all over the country. Factors such as number of members, medical, paramedical and non-medical staff and fund availability in the KAPI mainly influence the supply of services. CONCLUSIONS: Integrated care services are offered by the KAPI. However, more steps need to be taken towards the direction of other European countries' integrated care schemes, in order to improve both quality and quantity of the services provided

Prediction of climate change impacts on cotton yields in greece under eight climatic models using the aquacrop crop simulation model.

The impact of climate change on cotton yields in seven main arable crop sites in Greece (Agrinio, Alexandroupolis, Arta, Karditsa, Mikra, Pyrgos, Yliki) was investigated. The FAO AquaCrop (v.4) water driven model was used as a crop development simulation tool under eight climatic models (HadRM3, C4I, REMO MPI, ETHZ, CNRM, DMI-HIRHAM, KNMI, SMHI) based on IPPC’s A1B Climate Change scenario. The mean values of the models ensemble for temperature and precipitation were +1,8˚C until 2050 and +4 ˚C until the end of the century. The respective values for precipitation were -11% and -24%. The research was applied over three periods, 1961-1990, 2021-2050 and 2071-2099. AquaCrop validation for yield, biomass and canopy cover in respect to field data obtained from experiments carried out in Karditsa (Central Greece) from 2005 to 2007 was satisfactory on the account of Root Mean Square Error (0.17 to 0.49) and Index of Agreement (0.93 to 0.94). AquaCrop model was run using the Growing Degree Day mode in order to account better for the temperature variations. However, it gave erratic results for some specific climatic models (SMHI, KNMI, CNRM) in some years within the period 1961-1990. The predicted yields were highest in locations of western Greece (Agrinio, Arta, Pyrgos), whereas north-eastern Greece (Alexandroupolis) appeared to be less favoured by climate change. A tendency towards increasing yields by the end of the century was detected for the majority of the models. The efficiency of the eight models for yield predictions in the seven sites was assessed by means of a discriminant function analysis. On the account of their function coefficients over the seven sites, it was found that the models DMI and C4I explained consistently a great proportion of variation among the three time periods whereas the models ETHZ, SMHI and KNMI were more efficient in the periods 1961-1990, 2021-2050 and 2071-2099 respectively