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This paper considers the design and application of the electrohydraulic power unit for direct current installations. It discusses the advantages provided by the packaged power unit and advocates its selection for certain vehicular applications.

Within recent years, the use of electric remote controlled proportional valves in the mobile market has increased dramatically. Manufacturers have realised that the use of electro-hydraulics opens up new design opportunities such as remote valve installations, precise fingertip control, electronic management of hydraulic machines, in fact an exciting new world. Engineers have new options and possibilities to meet the customers demands for higher productivity, less power consumption and an ergonomically improved working environment. Fig. 1 shows a representative selection of valves, joy stick controllers and electrical accessories for mobile equipment such as the backhoe described in this paper. The electrical activation system is indicative of the direction development is taking. More and more electronics for control, regulation, monitoring and automating hydraulic systems are being used.

This paper describes four general types of servo-valves and lists some of the advantages and problems of their use in controlling construction machinery. It describes in detail two applications to construction machinery showing the associated electronic sensing and amplifying circuitry with the specific components in the amplifiers listed. This automatic control circuitry is comparatively simple and yet solves a difficult control problem in each case.

Recently, emerging technological developments in powertrain were mostly accompanied with electronics for efficient and precise control of various powertrain systems like engine, transmission, hydraulics, etc. Agricultural tractors are of no exception to this context. Most of the higher horsepower tractors above 50 HP are equipped with modern transmission systems such as Power-shuttle, Power-shift etc. having their wet clutch transmission and diesel engine controlled by an Electronic Control Unit. This is possible only with an engine that receives and provides electronic signals. Whereas a tractor with mechanical (non-electronic) engine is of predominant use in the Indian farm lands due to their low cost and immediate availability compared to that of an engine equipped with high-end electronics. Hence, there is a demand for low cost drivetrain with improved controls and without engine electronics.

The mobile hydraulic market is increasing its use of electronics for hydraulic control systems. In order to be more cost competitive, these systems are beginning to use proportional electro-hydraulic valves as opposed to the more traditional and costly servo valves. Proportional valves may be operated in open loop fashion or in a closed loop fashion which includes feedback transducers. In either case, it is important for the system designer and ultimately the end user to understand the different types of performance that may result by utilizing various coil drive strategies with proportional control valves.

Regular vehicle has the advantage of Engine resistance even when it is not fired, hence chances of vehicle roll back on gradients will be minimized. This is not the case for Electric vehicles, which uses an electric motor that does not have any resistance offered to wheels that prevent vehicle roll back on gradient. This leads to increased load on the conventional hydraulic brakes due to absence of engine inertia. Hence, there is a need for a low cost and reliable automatic braking system which can help in holding the vehicle and assists the driver during launch in case he need to stop at a gradient. An Electromagnetic brake (EM brake) system can be used as a solution for the above-mentioned requirement. EM brake can provide hill hold and hill assist effect in addition to automatic parking brake application when the vehicle is turned-off. This system will assist anyone who need to halt the vehicle at a gradient and then relaunch it without much struggle.

Market expectations for the next generation of gasoline engines are: improved performance for better driveability, lower toxic emissions to meet future legislation, and reduced fuel consumption to help meet future legislation linked to Green House Gas emissions (including CO2) and to counter the recent increase in fuel price. In addition, any new technical solution must be cost effective and applicable to a large volume of engines. In order to improve fuel efficiency, the combustion process needs to be optimized. A key technology to achieve this is fully variable valve actuation for both naturally aspirated and turbocharged engines (variable displacement, reduced pumping losses, Miller-Atkinson cycles). To futher improve, accurate control of ignition and the air/fuel ratio will also be required and are necessary for CAI-HCCI combustion. VALEO Engine Management Systems has, since 1998, been working on an infinitely variable valve actuation system based on a linear spring-mass actuator.

The paper presents the approach followed by Politecnico di Torino Vehicle Dynamics Research team to design an electro-mechanical Active Roll Control (ARC) system. The first part of the paper describes the targets of the system, which has to improve both comfort and handling. Different solutions for the implementation of the electro-mechanical actuation were evaluated. A prototype of the electro-mechanical Active Roll Control was built and experimentally tested in the Vehicle Dynamics Laboratory of the Department of Mechanics of Politecnico di Torino, by adopting a Hardware-In-the-Loop (HIL) test bench. The experimental results show the benefits of the system, both in a stand alone configuration and integrated with an Electronic Stability Control (ESC) system.

Electro-Mechanical Brake (EMB) is the brake system that is actuated by electrical energy and has a similar design with the Electric Parking Brake (EPB). It uses motor power and gears to provide the necessary torque and a screw & nut mechanism is used to convert the rotational movement into a translational one. The main difference of EMB compared with EPB is that the functional requirements of components are much higher to provide the necessary performance for service braking such as response time. Such highly responsive and independent brake actuators at each wheel lead to enhanced controllability which should result in not only better basic braking performance, but also improvements in various active braking functions such as integrated chassis control, driver assistance systems, or cooperative regenerative braking.

Electronic hydraulic control system adopted in the conventional vehicle continuously variable transmissions needs to consume energy incessantly for its oil pump driven by engine working continuously. As a result we can reduce the fuel consumption of the engine by removing the pump and replacing the control system with electro-mechanical one. The paper introduces two types of electro-mechanical controlled CVT (EM-CVT). One of them use gear train which is driven by a motor, and the other applies a planetary gear control device which uses spring to provide clamping force and electromagnetism clutches to control the planetary gears. The former is mainly applied to small torque CVT, for its clamping force brought from spring is limited. The latter can offer larger clamping force, and can be applied to prevalent CVT nowadays.

One of the key elements of response by many companies to the competitive environment is significant investments in new products. This increased competitive environment has been most influenced by international competition. Striving for “world class” products has to evolve if U.S. companies are to survive in the 1990s and beyond. While many large U.S. companies excel in basic research, with few exceptions they have had less than positive results in turning that advantage into a competitive edge as they introduce new products in the world marketplace. We cannot continue to believe that being first with a new technology is enough to enable us to thwart competition. Speed to market is extremely critical, as is the challenge of producing world class quality. Add to this the desire to recover our return on investment quickly.

This paper proposes an extension to curved surfaces of a design method of piezoelectric ice protection systems established for planar surfaces. The method is based on a finite element analysis which enables the fast computation of the resonant modes of interest to de-ice surfaces as leading edges. The performance of the modes of interest is assessed according to their deicing capacity estimated from the electro-mechanical coupling between the electric charge of the piezoelectric actuators and the strain energy in the structure. The method is illustrated on a NACA 0024 airfoil. Several experimental tests are conducted in an icing wind tunnel to verify the numerical predictions of the ice shedding and the operation of the system.

Hydraulic power requirements of military aircraft have increased significantly over the years. This has brought to the surface such issues as how best to manage the higher power requirements, which in many cases exist for only a small part of the duty cycle duration, and also how to minimize the system losses (heat rejection), which in turn can result in reduced cooling requirements. This paper summarizes some of the available data on the power requirements of military aircraft, discusses the inefficiencies of higher pressure systems being considered for high horsepower requirements, and describes the available approaches for better management of the high pressure/horsepower requirements, with respect to improving the operating efficiency of such systems.

The dual solenoid control valve was Initially designed as a low cost interface element between digital electronics and an automotive vacuum-spring motor such as the one found on Exhaust Gas Recirculation (EGR) valves. By using two coaxially located normally closed solenoids continuous air bleed is not required from the vacuum source. The direct acting solenoids have a large 0.5 SCFM flow capacity and a quick six millisecond opening and two millisecond closing time. The unit is well suited for pulse width modulation control. Ambient tests were conducted from -40°F to +250°F without any significant change in the performance characteristics of the unit. Possible applications for this electro-vacuum interface are in EGR valve control, Automatic Temperature Control (ATC), and as a remote throttle actuator on diesel engines.

This paper describes the design methodology and algorithm development towards the design of an automatic external gear-shifting and clutch-actuation system for a sequential gearbox with the aim of providing the drivers with easier and an efficient means of shifting gears. Automatically actuated manual transmission system bridges the gap between automatic and manual transmissions which provides the advantages of both type of transmissions. This would ideally leads to faster shifting time and provide significant benefits in the form of electronic-aids like launch control and traction control. Removal of mechanical clutching would reduce fatigue and lead to ergonomic benefit. Based on the benchmarking performed on an easily available ready-to-install aftermarket alternative, options will be considered for the actuating mechanism and the most feasible will be used to develop a shifting system.

With the increasing attention towards electric vehicles (EV), power electronics technology has become more prominent on vehicular systems. EV requires compact energy conversion and control technology to improve system efficiency and optimize the sizing of power components. Therefore, it is important to reduce thermal losses, while supplying an adequate amount of power to different EV devices. Silicon carbide (SiC)-based power semiconductors provide performance improvements such as lower power losses, higher junction temperature and higher switching frequency compared to the conventional silicon (Si)-based switching devices. High-frequency switching is preferred for power converters to minimize the necessity of passive filters; however, high-frequency switching causes additional thermal stress on semiconductor switches due to the increase in switching losses. The degradation of switching devices in power converters are primarily related to the junction temperature.

Lithium-ion (Li-ion) batteries are becoming widely used high-energy sources and a replacement of the Nickel Metal Hydride batteries in electric vehicles (EV), hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV). Because of their light weight and high energy density, Li-ion cells can significantly reduce the weight and volume of the battery packs for EVs, HEVs and PHEVs. Some materials in the Li-ion cells have low thermal stabilities and they may become thermally unstable when their working temperature becomes higher than the upper limit of allowed operating temperature range. Thus, the cell working temperature has a significant impact on the life of Li-ion batteries. A proper control of the cell working temperature is crucial to the safety of the battery system and improving the battery life. This paper outlines an approach for the thermal analysis of Li-ion battery cells and modules.

In the recent years, Hybrid and Electric Vehicles (EVs) have gained attention globally due to conventional non-renewable fuels becoming expensive and increasing pollution levels in the environment. Li-ion battery EV’s are most popular because of their better power density, spe. energy density and thermal stability. With the advent of battery EV’s, concerns regarding thermal safety of vehicle and its occupants has grown among the prospective customers. Temperature plays an important role in the performance of the Li-ion battery which includes cell capacity, charge output, vehicle range, mechanical life of the battery etc. For Li-ion cells, optimum operating range should be between 15-35 °C [1], and all cells must also be maintained within a ±5 °C variation band. Computational Fluid Dynamics (CFD) simulation can be used to get better insight of cell temperature inside battery. But CFD simulation process is complex, time consuming involving multi-physics and exhaustive computations.

A prototype fluidic fuel injection system for Spark-ignition(SI) engines has been established and tested. The fluidic injector unit combines a non-moving part wall reattachment type fluidic device powered by a solenoid pulser interface and an air-fuel mixing nozzle for good fuel atomization. It is demonstrated that the fluidic injector unit is capable of operating in a pulse modulated control mode and that the fluidic injector stage performs on-off switching in 1-1.5 msec.. The use of a fast response fluidic device coupled to a low power electric-fluidic interface potentially offers considerable cost and performance benefits for SI engine fuel injection systems.

The electromagnetic compatibility has been evaluated in vehicle components and systems, both individually and in the vehicle as a whole, already assembled with its numerous electrical and electronic equipment. The reason for this growing concern is the ever-increasing use of on-board electronics in cars. With the increasing speed of the processor in the modules and the demand for increasingly complex interfaces, it is necessary to develop more sophisticated control units, so the modules become ever more susceptible to electromagnetic fields. Therefore, the internal hardware of the control unit is designed to provide higher robustness of these components to comply in regards to EMC. The objective of this paper is to support the basic concepts that should be considered in building a printed circuit board (PCB) module for automotive application, and the correct component design distribution and ground strategy to avoid EMC issues.