3,122 research outputs found
Simulation of Electric Vehicles Combining Structural and Functional Approaches
In this paper the construction of a model that represents the behavior of an Electric Vehicle is described. Both the mechanical and the electric traction systems are represented using Multi-Bond Graph structural approach suited to model large scale physical systems. Then the model of the controllers, represented with a functional approach, is included giving rise to an integrated model which exploits the advantages of both approaches. Simulation and experimental results are aimed to illustrate the electromechanical interaction and to validate the proposal.Fil: Silva, Luis Ignacio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de IngenierĂa. Grupo de Electronica Aplicada; ArgentinaFil: MagallĂĄn, Guillermo AndrĂ©s. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de IngenierĂa. Grupo de Electronica Aplicada; ArgentinaFil: de la Barrera, Pablo Martin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de IngenierĂa. Grupo de Electronica Aplicada; ArgentinaFil: de Angelo, Cristian Hernan. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de IngenierĂa. Grupo de Electronica Aplicada; ArgentinaFil: Garcia, Guillermo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de IngenierĂa. Grupo de Electronica Aplicada; Argentin
DESIGN OF A SEMI-ACTIVE STEERING SYSTEM FOR A PASSENGER CAR
This thesis presents research into an improved active steering system technology for a
passenger car road vehicle, based on the concept of steer-by-wire (SBW) but possessing
additional safety features and advanced control algorithms to enable active steering
intervention. An innovative active steering system has been developed as 'Semi-Active
Steering' (SAS) in which the rigid steering shaft is replaced with a low stiffness resilient
shaft (LSRS). This allows active steer to be performed by producing more or less steer angle
to the front steered road wheels relative to the steering wheel input angle. The system could
switch to either being 'active' or 'conventional' depending on the running conditions of the
vehicle; e.g. during normal driving conditions, the steering system behaves similarly to a
power-assisted steering system, but under extreme conditions the control system may
intervene in the vehicle driving control. The driver control input at the steering wheel is
transmitted to the steered wheels via a controlled steering motor and in the event of motor
failure, the LSRS provides a basic steering function. During operation of the SAS, a reaction
motor applies counter torque to the steering wheel which simulates the steering 'feel'
experienced in a conventional steering system and also applies equal and opposite counter
torque to eliminate disturbance force from being felt at the steering wheel during active
control operation.
The thesis starts with the development of a mathematical model for a cornering road
vehicle fitted with hydraulic power-assisted steering, in order to understand the relationships
between steering characteristics such as steering feel, steering wheel torque and power boost
characteristic. The mathematical model is then used to predict the behaviour of a vehicle
fitted with the LSRS to represent the SAS system in the event of system failure. The
theoretical minimum range of stiffness values of the flexible shaft to maintain safe driving
was predicted.
Experiments on a real vehicle fitted with an LSRS steering shaft simulator have been
conducted in order to validate the mathematical model. It was found that a vehicle fitted with
a suitable range of steering shaft stiffness was stable and safe to be driven. The mathematical
model was also used to predict vehicle characteristics under different driving conditions
which were impossible to conduct safely as experiments.
Novel control algorithms for the SAS system were developed to include two main criteria,
viz. power-assistance and active steer. An ideal power boost characteristic curve for a
hydraulic power-assisted steering was selected and modified and a control strategy similar to
Steer-by-Wire (SBW) was implemented on the SAS system.
A full-vehicle computer model of a selected passenger car was generated using
ADAMS/car software in order to demonstrate the implementation of the proposed SAS
system. The power-assistance characteristics were optimized and parameters were determined
by using an iteration technique inside the ADAMS/car software. An example of an open-loop
control system was selected to demonstrate how the vehicle could display either under-steer
or over-steer depending on the vehicle motion.
The simulation results showed that a vehicle fitted with the SAS system could have a
much better performance in terms of safety and vehicle control as compared to a conventional
vehicle. The characteristics of the SAS system met all the requirements of a robust steering
system. It is concluded that the SAS has advantages which could lead to its being safely fitted
to passenger cars in the future.
Keywords: steer-by-wire, active steering, innovative, power-assisted steering, steering
control, flexible shaft, steering intervention, system failure, safety features
Performance and Safety Enhancement Strategies in Vehicle Dynamics and Ground Contact
Recent trends in vehicle engineering are testament to the great efforts that scientists and industries have made to seek solutions to enhance both the performance and safety of vehicular systems. This Special Issue aims to contribute to the study of modern vehicle dynamics, attracting recent experimental and in-simulation advances that are the basis for current technological growth and future mobility. The area involves research, studies, and projects derived from vehicle dynamics that aim to enhance vehicle performance in terms of handling, comfort, and adherence, and to examine safety optimization in the emerging contexts of smart, connected, and autonomous driving.This Special Issue focuses on new findings in the following topics:(1) Experimental and modelling activities that aim to investigate interaction phenomena from the macroscale, analyzing vehicle data, to the microscale, accounting for local contact mechanics; (2) Control strategies focused on vehicle performance enhancement, in terms of handling/grip, comfort and safety for passengers, motorsports, and future mobility scenarios; (3) Innovative technologies to improve the safety and performance of the vehicle and its subsystems; (4) Identification of vehicle and tire/wheel model parameters and status with innovative methodologies and algorithms; (5) Implementation of real-time software, logics, and models in onboard architectures and driving simulators; (6) Studies and analyses oriented toward the correlation among the factors affecting vehicle performance and safety; (7) Application use cases in road and off-road vehicles, e-bikes, motorcycles, buses, trucks, etc
RSL ROVER: Robotic Systems Laboratory Rugged Offroad Vehicle for Experimental Research
The goal of this project was to build an autonomous vehicle testbed for the Robotics Systems Laboratory. This testbed will be used by undergraduate, graduate, and faculty researchers to test different control methods, sensor combinations, vehicle control laws, and eventually autonomous navigation. This paper documents our accomplishments to achieve this goal; we built a hierarchical control system, robust actuator mounts, and an effective safety system. The result is a capable 6-wheeled offroad vehicle that can be electronically controlled by remote or directly by wire. A feed-forward control law was incorporated for speed control, yielding predictable performance given a desired speed. Actuators were tuned for fast, reliable response and wiring was kept organized. The team believes the vehicle will be a useful asset to the Robotic Systems Lab for future research. To improve upon our testbed, global positioning and a compass should be integrated along with other sensors that came with the vehicle such as a Lidar unit. With these additional components, the vehicle should be able to run autonomously
Feasible, Robust and Reliable Automation and Control for Autonomous Systems
The Special Issue book focuses on highlighting current research and developments in the automation and control field for autonomous systems as well as showcasing state-of-the-art control strategy approaches for autonomous platforms. The book is co-edited by distinguished international control system experts currently based in Sweden, the United States of America, and the United Kingdom, with contributions from reputable researchers from China, Austria, France, the United States of America, Poland, and Hungary, among many others. The editors believe the ten articles published within this Special Issue will be highly appealing to control-systems-related researchers in applications typified in the fields of ground, aerial, maritime vehicles, and robotics as well as industrial audiences
Volume 1 â Symposium
We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the worldâs most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is âFluid Power â Future Technologyâ, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresdenâs old town.:Group A: Materials
Group B: System design & integration
Group C: Novel system solutions
Group D: Additive manufacturing
Group E: Components
Group F: Intelligent control
Group G: Fluids
Group H | K: Pumps
Group I | L: Mobile applications
Group J: Fundamental
Vehicle dynamics virtual sensing and advanced motion control for highly skilled autonomous vehicles
This dissertation is aimed at elucidating the path towards the development of a future generation of highly-skilled autonomous vehicles (HSAV). In brief, it is envisaged that future HSAVs will be able to exhibit advanced driving skills to maintain the vehicle within stable limits in spite of the driving conditions (limits of handling) or environmental adversities (e.g. low manoeuvrability surfaces). Current research lines on intelligent systems indicate that such advanced driving behaviour may be realised by means of expert systems capable of monitoring the current vehicle states, learning the road friction conditions, and adapting their behaviour depending on the identified situation. Such adaptation skills are often exhibited by professional motorsport drivers, who fine-tune their driving behaviour depending on the road geometry or tyre-friction characteristics. On this basis, expert systems incorporating advanced driving functions inspired by the techniques seen on highly-skilled drivers (e.g. high body slip control) are proposed to extend the operating region of autonomous vehicles and achieve high-level automation (e.g. manoeuvrability enhancement on low-adherence surfaces). Specifically, two major research topics are covered in detail in this dissertation to conceive these expert systems: vehicle dynamics virtual sensing and advanced motion control. With regards to the former, a comprehensive research is undertaken to propose virtual sensors able to estimate the vehicle planar motion states and learn the road friction characteristics from readily available measurements. In what concerns motion control, systems to mimic advanced driving skills and achieve robust path-following ability are pursued. An optimal coordinated action of different chassis subsystems (e.g. steering and individual torque control) is sought by the adoption of a centralised multi-actuated system framework. The virtual sensors developed in this work are validated experimentally with the Vehicle-Based Objective Tyre Testing (VBOTT) research testbed of JAGUAR LAND ROVER and the advanced motion control functions with the Multi-Actuated Ground Vehicle âDevBotâ of ARRIVAL and ROBORACE.Diese Dissertation soll den Weg zur Entwicklung einer zukĂŒnftigen Generation hochqualifizierter autonomer Fahrzeuge (HSAV) aufzeigen. Kurz gesagt, es ist beabsichtigt, dass zukĂŒnftige HSAVs fortgeschrittene FahrfĂ€higkeiten aufweisen können, um das Fahrzeug trotz der Fahrbedingungen (Grenzen des Fahrverhaltens) oder Umgebungsbedingungen (z. B. OberflĂ€chen mit geringer ManövrierfĂ€higkeit) in stabilen Grenzen zu halten. Aktuelle Forschungslinien zu intelligenten Systemen weisen darauf hin, dass ein solches fortschrittliches Fahrverhalten mit Hilfe von Expertensystemen realisiert werden kann, die in der Lage sind, die aktuellen FahrzeugzustĂ€nde zu ĂŒberwachen, die StraĂenreibungsbedingungen kennenzulernen und ihr Verhalten in AbhĂ€ngigkeit von der ermittelten Situation anzupassen. Solche AnpassungsfĂ€higkeiten werden hĂ€ufig von professionellen Motorsportfahrern gezeigt, die ihr Fahrverhalten in AbhĂ€ngigkeit von der StraĂengeometrie oder den Reifenreibungsmerkmalen abstimmen. Auf dieser Grundlage werden Expertensysteme mit fortschrittlichen Fahrfunktionen vorgeschlagen, die auf den Techniken hochqualifizierter Fahrer basieren (z. B. hohe Schlupfregelung), um den Betriebsbereich autonomer Fahrzeuge zu erweitern und eine Automatisierung auf hohem Niveau zu erreichen (z. B. Verbesserung der ManövrierfĂ€higkeit auf niedrigem Niveau) -haftende OberflĂ€chen). Um diese Expertensysteme zu konzipieren, werden zwei groĂe Forschungsthemen in dieser Dissertation ausfĂŒhrlich behandelt: Fahrdynamik-virtuelle Wahrnehmung und fortschrittliche Bewegungssteuerung. In Bezug auf erstere wird eine umfassende Forschung durchgefĂŒhrt, um virtuelle Sensoren vorzuschlagen, die in der Lage sind, die BewegungszustĂ€nde der Fahrzeugebenen abzuschĂ€tzen und die StraĂenreibungseigenschaften aus leicht verfĂŒgbaren Messungen kennenzulernen. In Bezug auf die Bewegungssteuerung werden Systeme zur Nachahmung fortgeschrittener FahrfĂ€higkeiten und zum Erzielen einer robusten WegfolgefĂ€higkeit angestrebt. Eine optimale koordinierte Wirkung verschiedener Fahrgestellsubsysteme (z. B. Lenkung und individuelle Drehmomentsteuerung) wird durch die Annahme eines zentralisierten, mehrfach betĂ€tigten Systemrahmens angestrebt. Die in dieser Arbeit entwickelten virtuellen Sensoren wurden experimentell mit dem Vehicle-Based Objective Tyre Testing (VBOTT) - PrĂŒfstand von JAGUAR LAND ROVER und den fortschrittlichen Bewegungssteuerungsfunktionen mit dem mehrfach betĂ€tigten Bodenfahrzeug âDevBotâ von ARRIVAL und ROBORACE validiert
Compendium in Vehicle Motion Engineering
This compendium is written for the course âMMF062 Vehicle Motion Engineeringâ at Chalmers University of Technology. The compendium covers more than included in that course; both in terms of subsystem designs and in terms of some teasers for more advanced studies of vehicle dynamics. Therefore, it is also useful for the more advanced courses, such as âTME102 Vehicle Modelling and Controlâ.The overall objective of the compendium is to educate engineers that understand and can contribute to development of good motion and energy functionality of vehicles. The compendium focuses on road vehicles, primarily passenger cars and commercial vehicles. Smaller road vehicles, such as bicycles and single-person cars, are only very briefly addressed. It can be mentioned that there exist a lot of ground-vehicle types not covered at all, such as: off-road/construction vehicles, tracked vehicles, horse wagons, hovercrafts, and railway vehicles.Functions are needed for requirement setting, design and verification. The overall order within the compendium is that models/methods/tools needed to understand each function are placed before the functions. Chapters 3-5 describes (complete vehicle) âfunctionsâ, organised after vehicle motion directions:\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 3:\ua0Longitudinal\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 4:\ua0Lateral\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 5:\ua0Vertical\ua0dynamicsChapter 1 introduces automotive industry and the overall way of working there and defines required pre-knowledge from âproduct-genericâ engineering, e.g. modelling of dynamic systems.Chapter 2 also describes the subsystems relevant for vehicle dynamics:âą Wheels and Tyre\ua0âą Suspension\ua0âą Propulsion\ua0âą Braking System\ua0âą Steering System\ua0âą Environment Sensing SystemThe compendium is released in a new version each year, around October, which is the version your read now. A "latest draft" is more frequently updated and often includes some more, sometimes unfinished, material: https://chalmersuniversity.box.com/s/6igaen1ugcjzuhjziuon08axxiy817f
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