Design methods for mobility

Current automatic control system uses linear mathematical models to validate automatic flight control for airplanes. Gain scheduling, non linearity and improved feedback through simulation are also introduced. Very computers operate the actuators in order to keep the airplane on the right path, in the current trim and with the proper safety margin. Some engineers are testing fuzzy control logic to control airplanes and UAVs (Unmanned Aerial Vehicles). The result is brilliant, since very simple controllers are able to fulfill the specification with little "knowledge" about the airplane performances. This means that fuzzy controllers are very robust since they are able to operate with much degraded aerodynamics or with reduced thrust. However no one was able to validate the airplane/fuzzy controller with a mathematical proof. So it is not sure that it will works in any condition. By the way the same happens for the airplane/human pilot model. So a mathematical proof is still required also for this later solution. On the other side, very accurate, time based non linear mathematical models are available for flight simulation. These models are used in several fields ranging from development to training. In recent years computers that can run these accurate models in fractions of seconds were marketed at very low prices. The idea introduced in this paper is to run an accurate mathematical model on some of these fast autopilot computer in order to optimize the sequence of commands to be inputted to the FBW system of the airplane in order to keep the path in the safest way possible. For this purpose it is necessary to have enough computing power to calculate this best solution at a rate compatible to a correct control of the airplane. In this paper we will demonstrate that these computing resources are already available and it is predictable that the computing speed of future years will allow running even more sophisticated simulators. The question may be: why use more complicated systems when current control system fulfills satisfactorily the same task in a cheaper and more reliable way? The answers are several. At first it is a matter of robustness, what happens if the yaw damper fails or the actuator of the left ailerons is unable to fulfill its task or the tail is ripped off? In this case standard systems are not able to take the airplane to the ground safely even if it is indeed possible to control the airplane by a coordinate action of the remaining control surfaces. Optimization means that it is possible to reduce the stress on structures in order to improve aircraft life, to find the control sequence that assure the mean fuel consumption or to prefer the shortest time possible to reach the required trim on the right path. In other words it is more flexible. It is also possible to monitor aircraft performance in order to evaluate external or internal disturbances. Air turbulences, wind gusts may be controlled in order to optimize structural integrity or passenger comfort. Internal disturbances, as defective functioning of components or controls, occasional failure of sensors may be diagnosed, in some cases corrected in other simply reported after landing. The reliability improvement is not the latest benefit. As a rule of the thumb more electronics or more components means less reliability with the exception of redundancy and this is the case of this paper.

Keywords: Airplane control , Automatic control

A method to perform the preliminary design of an impeller for an extremely high pressure ratio centrifugal compressor is introduced in this paper. The equations used are fully detailed and a design procedure is introduced. This design procedure required a GA (Genetic Algorithm) optimization to obtain an acceptable optimum result. It is demonstrated that a 8:1 compressor can be designed for a mass flow of 500 kg/h. This GA optimized initial design should be then be validated through CFD (Computational Fluid Dynamics) simulation and then tested on a test bench. However, the initial design phase is critical, since a CAD model of the impeller is needed to start the simulation process. In our case this initial phase couldn't be inspired by existing design, since none were found. Aircraft and Helicopter engines do not have the problem of turbo lag, since fan/propeller inertia eliminates this problem. On the contrary these engines necessitate of performance at altitudes (flight levels) much higher than automotive applications. Small turbochargers with high compressor ratio are not available on the market, so a special design is needed.

Performance of electronic controlled diesel engine is depended on quality of the map(s). In this paper, the implementation of an electronic-control map in common rail diesel engine is made, the character of operational profile in diesel engine and rule of typical profile data obtained from experiment is analyzed, a method of developing these surfaces from very few data point is applied. The particular application of aircraft and elicopter common rail direct injection diesel engines is considered. The steps of this experimental optimization activity is presented in order to test to operational profile demand. This demand is very different from the automotive to the aircraft/helicopter application. The preparation of the test engine(s) and of the test electronics for brake tests is completely different. Also the mapping technique differs substantially being the primary objectives widely different.

Keywords: Aircraft , Common rail , Diesel engine , Electronic control , Fitting surface , Helicopter , Mapping

This paper introduces an original method for the preliminary calculations and the turbomatching of a dual stage high altitude turbocompounding system. This method is conceived to use modified automotive commercial turbochargers along with electric motor/generators. The method used is innovative and uses only the data commonly available from the manufacturer. In the example described herein, full power and throttle control are achieved up to 10, 000m (32, 000ft). The engine is a Common Rail Direct Injection Diesel engine derived from the automotive market. The calculation method and the problems connected are widely discussed. For this application turbocompunding is a good option that partially compensates the unavoidable increase in TOW (Take Off Weight). In drones that have relatively large batteries, the ERS (Energy Recovery System) does not increase the air vehicle mass.

Keywords: Diesel common rail , Energy recovery , Turbocompunding system

A Fiat 1.9jtd diesel engine has been extensively reviewed to output 300HP. This paper introduces a multiple stage turbocharging system that uses commercial turbocharger, taken from the catalogue of a popular manufacturer. The calculation method and the problem connected are widely discussed. Along with the problem that may arise in using these off the shelf unit. The quite heavy result advice the user to adopt ad-designed turbochargers for this task.

Common rail automotive diesels are always turbocharged. This engine works at limited altitude and should output torque at low rotational speeds. Not so for engines that work coupled to propeller and fans. This is the case of aircraft and helicopter engines. In this case it is important to have high output power at high rpm and to keep throttle authority and power as high as possible. Some basic concepts to achieve this result are introduced in this paper. Single turbocharging systems are introduced and an option to improve the altitude performance is discussed. Far from being exhaustive, this paper is an initial step in the long and awkward technology of aircraft common rail diesels. The basic combustion principles and the basic concepts for efficiency are also discussed.

Keywords: Aircraft , DIDs , Rail automotive diesels , Turbocharging systems

Ambient Assisted Living (AAL) is one of the most strategic research fields of research due to the increasing aging of the world population and the developments of assistive technologies, which enable people with specific demands to live longer and better by providing specific care. It has been demonstrated that AAL technologies provide effective support to frail people and their application is increasing in home and medical contexts with positive effects on costs reduction. However, such models have been rarely applied outside the domestic context. This paper describes the application of AAL concepts to manufacturing in order to support frail people to properly handle machine tools and complex systems. It presents an industrial case study focusing on machine tool operators: under these circumstances frailty assumes a broad sense as people have to carry out highly specialized jobs and also mild deficiencies can represent a frailty (i.e. slight reduction in sight, hands that are not perfectly steady, slightly reduced mobility or human force). The case study in particular aims at designing an adaptive user interface based on AAL principles and user-centered approach to support frail operators to work better and more safely.

This paper introduces the implementation of a few algorithms based on fuzzy logic to improve the performance of a "Fly-by-wire" (FBW) "Digital Flight Control System" (DCFS). These algorithms have been tested on a flight simulator type "FNPT II". This simulator was entirely developed at the Laboratory of Aerospace Engineering of the University of Bologna (Forlì site). The algorithms should be simple (reliable) and quick in order to avoid response delay. They should also bring a true advantage in the FBW system. The proposed solutions are on the active filtering of the inputs an adaptive tolerance implementation for the identification of faulty sensors and their deactivation. The field in which this study has demonstrated greater effectiveness is in SW filtering of input signals, where a simple and effective algorithm was implemented. Finally, extremely simple hardware techniques to reduce input noise are also described.

Keywords: Digital flight control system (DCFS) , Flight simulator , Fly-by-wire (FBW) , Noise reduction

A combined employment of an air spring and a magnetorheological damper is proposed for the vibration control. The proposed device is characterized by the possibility to change stiffness and damping, making it fully versatile and functional to overcame the several issues that can be found in vibration control. The integrated solution is based on the parallel of both an air spring and a magnetorheological damper. The solution allows to select the better compromise to enhance the opposite aspects of ride and handling.

Keywords: Air spring , Damper , Handling , Magnetorheological fluid , Ride

Traffic calming devices on urban streets, such as elevated pedestrian crossings, speed bumps and roundabouts, are increasingly used, raising a real problem in relation to the on-board comfort that passengers perceive. To measure vibrational comfort related to traffic calming devices that passengers of the public transport perceive, an acquisition system called ASGCM (Autonomous System for Geo-referenced Comfort Measurements) has been developed, taking as a reference the European regulations on rail transports. ASGCM permits to link each measurement of vibration, ground velocity and acceleration with geographical information resulting from a GPS. In this way a map of a comfort index, statistical surveys and correlation between on-board comfort and traffic calming, can be directly obtained by any Geographic Information System (GIS), able to query a centralized remote database, which was developed ad-hoc. A large number of experimental tests has been performed to define a vibrational comfort index and to collect a large dataset that allows statistically significant comparisons between different infrastructures and their characterization. The proposed technique can also be useful for diagnostics purposes, such as vehicle comparison and road maintenance state monitoring.

Keywords: Geo-referenced comfort measurement , Thematic maps , Vibrational on-board comfort

This paper describes a shape and force tracking approach aimed for the assessment and training of patients' upper extremities functionalities, while performing 2D tasks in a post-stroke rehabilitation program. The 2D tasks are assisted by a Multi-modal Guidance System (MGS), which consists in a combination of visual, haptic and sound interaction. The device enables users to haptically interact with a virtual template, which acts as a virtual tool path taking advantage of its force feedback capabilities while the patient performs a 2D task, as sketching and hatching operations. Furthermore, the patient receives sound information, which provides audio feedback related to the hand velocity. By tracking the shape and the forces required to complete the tasks according to the visual feedback provided on the computer screen, the system can inform about quantitative measurement of a patients progress. The paper concludes by presenting a preliminary test using the device for sketching and hatching operations.

In this research work, we present a Multimodal Guidance System (MGS) whose aim is to provide dynamic assistance to persons with disabilities (PWD) while performing manual activities such as drawing, coloring in and foam-cutting tasks. The MGS provides robotic assistance in the execution of 2D tasks through haptic and sound interactions. Haptic technology provides the virtual path of 2D shapes through the point-based approach, while sound technology provides audio feedback inputs related to the hand's velocity while sketching and filling or cutting operations. By combining this Multimodal System with the haptic assistance, we have created a new approach with possible applications to such diverse fields as physical rehabilitation, scientific investigation of sensorimotor learning and assessment of hand movements in PWD. The MGS has been tested by people with specific disorders affecting coordination, such as Down syndrome and developmental disabilities, under the supervision of their teachers and care assistants inside their learning environment. A Graphic User Interface has been designed for teachers and care assistants in order to provide training during the test sessions. Our results provide conclusive evidence that the effect of using the MGS increases the accuracy in the tasks operations. Implications for RehabilitationThe Multimodal Guidance System (MGS) is an interface that offers haptic and sound feedback while performing manual tasks.Several studies demonstrated that the haptic guidance systems can help people in recovering cognitive function at different levels of complexity and impairment.The applications supported by our device could also have an important role in supporting physical therapist and cognitive psychologist in helping patients to recover motor and visuo-spatial abilities. © 2014 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted.

Keywords: Disabilities , Down syndrome , Haptic feedback , Manual tasks , Multimodal guidance device , People without skills

This paper describes the multidisciplinary optimization of an airship with unconventional configuration. The shape of the airship is based upon two semi-ellipsoids, whose axis ratios can be altered for optimization purpose. The parameters to optimize are volume, ratio between longitudinal and lateral semi-axis, ratio between vertical and lateral semi-axis, percentage of the top surface covered by photovoltaic films, and dimension of the tail. The objective of the optimization is to reduce the mass of the airship by keeping the equilibrium between buoyancy and weight as a constraint, reaching the design speed while maintaining the static longitudinal stability of the vehicle. The mathematical model developed to evaluate airship features includes the computation of the ballonet volume, a weight breakdown, considerations about the energy storage for night operations, the power system, and the stability. Six heuristic optimization strategies have been applied to achieve the best solution; some case studies have been developed, and the final optimal configurations found by algorithms have been analyzed to validate the optimization framework. The approach demonstrates that the heuristic optimization strategies used are good tools for the conceptual design of unconventional airship since this problem requires a multidisciplinary approach and several parameters including aerodynamics, propulsion, mass breakdown, aerostatics, and stability. These parameters are strongly dependent on each other and they must be considered together to obtain an optimum and balanced design.

Hybrid and electric vehicles are taking an increasingly important slice of the market, gaining much interest from major car manufacturers which have decided to invest in this sector, taking as example the pioneers like Toyota. The key factor to hybrid and electric vehicle success is a good overall mileage achieved from the battery back or powertrain. The purpose of this work is to provide a support to design, testing, and development of such vehicles through the implementation of a mathematical model in order to simulate the operation and predict the performance of a generic ground vehicle equipped with either a purely electric or a hybrid-electric type powertrain. The model should enable the user to estimate the impact of various control strategies on mileage range, efficiency, energy consumption, etc. The model should also allow for a significant time to market reduction with all the related benefits in terms of cost etc. A validation is also provided, based on the application of this tool on a so-called micro-car (0.5t GVW class). Thanks to a joint research project with the manufacturer it has been possible to compare model results with real-world data directly obtained during road testing with the help of a data acquisition system. © 2014 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.

Keywords: Electric vehicle , Hybrid electric vehicle , Mathematical modelling , Performance prediction

It is well known that vehicle slip angle is one of the most difficult parameters to measure on a vehicle during testing or racing activities. Moreover, the appropriate sensor is very expensive and it is often difficult to fit to a car, especially on race cars. We propose here a strategy to eliminate the need for this sensor by using a mathematical tool which gives a good estimation of the vehicle slip angle. A single-track car model, coupled with an extended Kalman filter, was used in order to achieve the result. Moreover, a tuning procedure is proposed that takes into consideration both nonlinear and saturation characteristics typical of vehicle lateral dynamics. The effectiveness of the proposed algorithm has been proven by both simulation results and real-world data. © 2014 Taylor & Francis.

Keywords: analytic model , extended Kalman filter , real-word validation , tyre modelling , vehicle dynamics , vehicle slip angle

This paper focuses on the design of the power management strategy as the key factor in improving the performance in terms of the efficiency, the range and the fuel consumption for a small-scale series hybrid electric vehicle. A complex hybrid vehicle system is considered, and a practically realisable and traceable neurofuzzy strategy for improving the vehicle efficiency is introduced. The method results in extending the vehicle's range while deciding when to switch the internal-combustion engine on or off as a function of the state of charge of the battery and the electrical power produced from the generator. Consequently, the speed of the internal-combustion engine (i.e. the current produced) is determined as a function of the driving conditions. Suitable tests were performed in order to verify the effectiveness of the proposed strategy; the verification tests were carried out using a consolidated model which also includes real-world experimental vehicle data. The results show that, by using the proposed power management strategy, a good compromise between the efficiency, the range and the fuel consumption can be obtained in many practically useful driving conditions. © 2014 IMechE.

Keywords: Electric vehicles , hybrid vehicles , intelligent vehicles , vehicle control systems , vehicle electronics

To-day America's Cup catamarans have many innovative features such as hydrodynamic foils and rigid wings instead of soft sails. They are designed not only to float but also to heave and "fly" over the sea surface. These new features require new skills that the crew must acquire. The work presented in the paper deals with this problem and describes a foiling catamaran simulator designed for training purpose. The simulator is designed primarily to interact with the in-training team and to feedback the crewmen with realistic physical reactions in an immersive scenario; secondly the simulator gives the opportunity to compare different race strategies and to select the most promising one. The main features of the simulator are illustrated, some graphical evaluations are displayed and results are discussed.

Keywords: America's Cup , Crew Training , Human Interface , Real-time Simulator , Sailing Simulator

In order to optimize the design of the thermodynamic cycle of a turbine (Brayton cycle) for using modern common rail as an "active" combustion chamber it was intended to write the present paper. About the present case, the "active" combustion chamber produces a large amount of the mechanical energy that drives the fan. The incoming air is compressed by the compressor, then it is refrigerated and inputted in the diesel engine. A high pressure common rail system optimizes the combustion in the diesel combustion chamber and the expansion begins inside the diesel engine. At the exhaust of the combustion chamber a turbine completes the expansion of the hot gases. A nozzle accelerates the exhaust from the turbine to increase the overall thrust. The mechanical energy from the diesel and from the turbine powers the compressor and the fan. The system can be seen as a turbocharged diesel engine with the turbocharger that outputs energy to the turbofan, increasing the output power and or the efficiency. A diesel-turbine compound can be realized in this way. The coupling of the two systems may be obtained in several different ways. The simplest is to put on the same shaft the compressor, the diesel crankshaft and the turbine. In front of the compressor a speed reducer drives the fan. A second example is to connect the turbine and the diesel on to electric generators. Electric engines are connected to the compressor and to the fan. The traditional turbodiesel has the compressor coupled to the turbine, and the diesel engine that moves the fan. In this latter case, however, the turbine does not energize the fan. Many other hybrid and nonhybrid solutions are possible. The problem is to optimize temperatures, pressures and rpm to the different machines that form the compound. The availability of many experimental data for diesel and turbines makes it possible to obtain a design of a "true" feasible optimum Diesel-Brayton cycle. This efficiency figure justifies the huge manufacturing and development costs of these turbocompound engines [1-4].

Keywords: Feasible optimum Diesel-Brayton cycle

In the activity of injection mapping optimization, a good degree of knowledge on how a common rail injection works is strictly necessary. This paper is aimed to summarize the basic knowledge about turbocharged Common Rail Direct-injection Diesel engines (CRDID). It is possible to use automotive CRDIDs on aircrafts and helicopter; however their use is very different for the original car installation. For this reason a complete rethinking of the engine and the way the engine control is performed is strictly necessary. For this reason the engine should be reprogrammed for the new application. To perform this activity it is strictly necessary to know how the original automotive application works. This paper is aimed to this objective, in order to point out the differences with the automotive installation and the new optimization functions. The combustion process of turbocharged CRDID, equipped with high pressure common-rail fuel injection systems, with different boost pressures, injection pressures, and fuel quantities are introduced. The influence of the injection and the swirl mode on the ignition delay and the flame propagation is analyzed. The sac hole nozzles with a variable number of holes and different injector types (electromagnetic/piezoelectric) are also briefly described. An experimental analysis of the combustion process is briefly discussed along with spray penetration, dispersing angle, velocity, the distribution/evaporation of the fuel droplets, ignition delay, ignition location, combustion progression. The applied swirl has not an influence on the spray penetration, but it is extremely important for the ignition and the combustion process. On the contrary the swirl itself is reduced by the injected amount of high pressured fuel. The droplet turbulence increases from the center of the combustion chamber of the spray radial rapidly decreases. The difference in the combustion of CRDIDs, traditional diesel engines and spark ignition engine is also briefly discussed. Finally the difference from automotive and aircraft and helicopter CRDIDs, from the combustion tuning point of view is discussed. Optimum combustion (and mapping) is also introduced as basic concepts.

Keywords: Aircraft , Turbocharged di-diesel-engines

Composite structures such as CFRP offer significant weight reduction over the conventional aluminum alloys for aircraft. Weight reduction improves fuel efficiency of the aircraft by approximately 20% which results in cost savings and simultaneously reduces the operational environmental footprint. However, the new aluminum-lithium alloys offer significant improvements and are viable alternatives to CFRP. Aluminum lithium alloy 2195 with Friction Stir Welding is introduced as a successful alternative to CFRP primary structures. A "thick skin" monocoque design with integral stringers as crack stoppers is discussed. An old Macchi 205 WWII fighter plane has been redesigned both in CFRP and 2195-FSW for comparison. The final designs are comparable in weight, but 2195-FSW is more competitive based on mass production costs, reparability, and environmental impact. Macchi 205 airplane is used due to in-depth experience with the original aircraft geometry and loads. Knowledge gained here can be directly transferred to larger structures, from corporate jets to large transport category airplanes [1].

Keywords: 2195-FSW , Aircraft structures , Aluminum alloys , CFRP , Composite material