Browse Topic: Drive-by-wire

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Combined Longitudinal and Lateral Control for Automated Lane Guidance of Full Drive-by-Wire Vehicles2015-01-03214/14/2015
This paper presents a simultaneous longitudinal and lateral motion control strategy for a full drive-by-wire autonomous vehicle. A nonlinear model predictive control (NMPC) problem is formulated in which the nonlinear prediction model utilizes a spatial transformation to derive the dynamics of the vehicle about the reference trajectory, which facilitates the acquisition of the tracking errors at varying speeds. A reference speed profile generator is adopted by taking account of the road geometry information, such that the lateral stability is guaranteed and the lane guidance performance is improved. Finally, the nonlinear multi-variable optimization problem is simplified by considering only three motion control efforts, which are strictly confined within a convex set and are readily distributed to the four tires of a full drive-by-wire vehicle. Simulation results demonstrate the capability of the proposed controller to follow the reference trajectory while adjusting the vehicle speed automatically.
Song, Pan, Zong, Changfu, Tomizuka, Masayoshi
Objective Driveability Development of Motorcycles with AVL-DRIVE2014-32-002011/11/2014
Originally developed for the automotive market, a fully automatic real-time measurement tool AVL-DRIVE is commercially available for analyzing and scoring vehicle drive quality, also known as “Driveability”. This system from AVL uses its own transducers, calibrated to the sensitivity and response of the human body to measure the forces felt by the driver, such as acceleration, shock, surging, vibration, noise, etc. Simultaneously, the vehicle operating conditions are measured, (throttle grip angle, engine speed, gear, vehicle speed, temperature, etc.). Because the software is pre-programmed with the scores from a multitude of different vehicles in each vehicle class via neural networks and fuzzy logic formula, a quality score with reference to similar competitor vehicles is instantly given. This tool is already successfully implemented in the market for years to investigate such driveability parameters for passenger cars. Due to the fact that electronic systems more and more find their way into the 2-wheeler applications, motorcycle manufacturers are facing a lot of challenges and these are increasing from year to year. Increasing power, with the goal to reduce fuel consumption is just one of the targets OEMs have to deal with. Beside that engines with different calibration versions to fit into various motorcycle classes are brought into the market and need to be objectively judged to fulfil the demands of the different motorcycle applications. At the moment the main point of interests are: drive by wire traction control, ABS different driving modes (throttle/ignition maps) electronic suspension automatic and semiautomatic transmissions Some of these development areas are new for motorcycle manufacturers, but they have to deal with it to stay competitive. On top of these points all of them have to come together to the attribute: “FUN TO DRIVE”. This paper describes the process of adding the capability to assess these tasks in the AVL driveability measurement tool and gives examples how the tool supports the increasing effort in such calibration tasks for motorcycles. The objective driveability tool AVL-DRIVE is providing a lot of experiences on the tasks listed above, based on mature and proven automotive background. Beside the shown examples using this real time driveability assessment tool for more efficient new technology development, the paper summarizes the benefits for motorcycle manufacturers all around the world.
Falk, Patrick, Hubmann, Christian
Digital DC CDI for Small Engines: Low Cost Solution and Challenges with 8 Bit Microcontroller2014-01-286010/13/2014
Emerging markets like India is very cost sensitive for small engines like motorcycle. Capacitive discharge Ignition (CDI) with carburetor is popular low cost solution with good engine performance. CDI system accumulates charge inside the ignition capacitor, until a point at which a signal allows to release discharge of the stored charge to the spark plug through high tension coil. This paper will focus on single spark digital two teeth DC CDI solution and below design challenges with two sparks. 1 Higher power dissipation in step up fly back converter 2 Need higher CPU speed, flash size and restrictions on engine map profile for advance angles This paper will elaborate above problems and their solutions with test results for optimizing solution cost and achieve performance. Solutions include, exploring 8 bit microcontroller peripherals usage and smart software to boost MCU performance for engine dynamic conditions and to achieve lower losses in flyback converter.
Ugale, Ramdas
Smart Electro-Mechanical Actuation for Drive-by-Wire Applications2004-21-004510/18/2004
This paper will describe the technical capabilities and vehicle design freedom made possible by drive-by-wire powertrain and chassis control systems, using SKF's Smart Electro-Mechanical Actuating Unit (SEMAU) technology. It will describe the advantages to the vehicle users and vehicle manufacturers of integrating electronic controls into the previously mechanically, hydraulically, and pneumatically actuated function and also show how mechatronic solutions can contribute to these advantages. The paper will refer to the FILO, NOVANTA, and GM Hy-wire concept vehicles, which utilize “by-wire” technology, in order to illustrate these advantages.
Brown, Steven, Holweg, Edward
Low Cost Fault Tolerant and Redundant Multiplex Wiring System for Automotive Applications2004-01-15723/8/2004
A low cost fault tolerant and redundant multiplex wiring system specifically designed for automotive applications is described in this paper. Although there are many multiplex wiring systems are being used to simplify the car wiring harness, but very few are low cost, fault tolerant and redundant at the same time. Most of the system address mainly the protocol and software issues and neglected the reliability of the multiplex wiring system. This paper addresses the fault tolerant and redundancy of the system and use hardware based integrated circuit to convert from parallel to serial at the transmitter side and serial to parallel at the receiver side.
Shih, Kelvin
Analysis of a F1 Car Hydraulic Circuit Dynamic Behavior2001-01-11623/5/2001
This paper deals with the study of the dynamic behavior of a F1 car gear selection hydraulic circuit, when involved in different shift transients. In the first part of the paper the actual circuit is described, and the main hypotheses adopted for the numerical modeling of the hydraulic power unit, of the control valves, of hydraulic pipes and of the actuators involved in the gear shift cycles are introduced. Particular attention is devoted to the actuators actual sequences, as applied by the Electronic Control Unit (ECU) to the servo-valves deputed to actuators control. The strategy to define each gear shift cycle in terms of actuators working position in time domain is chosen, using the frequency map of each servo-valve. A numerical vs. experimental comparison of the behavior of the actuators involved in the gear selection (during about 50 ms for an up shifting and 100 ms for a down shifting) is performed, with the target to define the validity limits of the numerical model results. Finally, the paper reports the analysis of those hydraulic variables not controlled by the on board diagnostic, with the aim to analyze the behavior of the power unit and of the pipes when submitted to the sudden hydraulic power request correspondent to a gear shift.
Borghi, M., Milani, M., Piraccini, M., Flandoli, M.
Influencing Dynamic Handling Response with Manipulation of Advanced All Wheel Drive Systems2000-01-346012/4/2000
Trucks and sport utility class vehicles are established as choice of daily transportation in the US. A new breed of vehicles, commonly referred as “crossover vehicles”, based on passenger car derived platforms, are rapidly filling in the ranks between trucks and automobiles. Most of these vehicles are equipped with relatively sophisticated all wheel drive systems. This sophistication is necessary to fulfill the target mission of these vehicles, to provide an automatic and effortless all wheel drive capability while retaining refined on road comfort. Building on some of the existing systems and sensors, and integrating with other vehicle systems such as ABS, traction control and stability control systems, it is possible to enhance handling response by creating a moment along yaw axis. Pitch and roll movements can also be indirectly influenced. Further possibilities and enhancements will be feasible when drive by wire systems and active suspensions will become available. While most of these enhancements do not improve ultimate cornering and braking limits, they help average driver to recover or avoid critical maneuvers, improving safety and satisfaction of the users. This paper discusses several drivetrain-based approaches and concepts enhancing the on road capabilities of subject class vehicles.
Okcuoglu, Murat
The Driving Need for Human Factors in the Car of the Future2000-01-30758/21/2000
The car of the future will be very different from that which we know today - no longer just a mechanical transportation device, but a mobile communications and entertainment platform providing many new functions and services to the occupants. The use of cellular telephones whilst driving is already a source of major concern and further legislation regarding phone usage will undoubtedly be forthcoming. The future will also add display based navigation, internet access, e-commerce and other location dependent services which will increase the drivers cognitive load. We will also see driver assistance systems such as adaptive cruise control, collision avoidance warnings and vision enhancement systems which will change the driving task and could potentially reduce cognitive load almost to the level of autopilot monitoring. As the nature of the in-vehicle activity therefore evolves from being a perceptual-motor driving task to that of a communications and vigilance task (set against a background of infotainment services) then we can not only anticipate emergent behaviors but will also see a new need for the management of multimodal information presentation to the driver according to his driving circumstances and indeed, personal preferences. Consequently driving could be as different from what we know today, as today is from the time of leather helmets and driving goggles. The aim of this presentation is to provide an overview of the major human factors and safety issues which these new systems are raising and which will be fundamental to their effective and safe use as well as to their commercial viability and success.
Wheatley, David J.
Passive Learning; Putting Simplicity Back Into Driving9519588/1/1995
The future of automotive transportation is very promising with many exciting systems and features designed to enhance customer comfort, convenience and safety. That technology will be meaningless if it is not designed to be readily accepted and easily understood by the customer. A passive system that quietly and unobtrusively “learns” driver tendencies and preferences and uses that knowledge to adjust various vehicle systems will minimize customer apprehension about new technology and increase it's acceptance and usage. Future transportation technology must be designed to adapt to each customer's expectations and abilities or we are apt to receive messages like ..... Disc Error On Driver One!
Doble, Michael E.
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