Search results for "Vehicle dynamics"
showing 10 items of 41 documents
Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers
2023
This brief addresses the robust lateral control problem for self-driving racecars. It proposes a discrete-time estimation and control solution consisting of a delayed unknown input-state observer (UIO) and a robust tracking controller. Based on a nominal vehicle model, describing its motion with respect to a generic desired trajectory and requiring no information about the surrounding environment, the observer reconstructs the total force disturbance signal, resulting from imperfect knowledge of the time-varying tire-road interface characteristics, presence of other vehicles nearby, wind gusts, and other model uncertainty. Then, the controller actively compensates the estimated force and as…
MODELING TORQUE TRANSMISSIBILITY FOR AUTOMOTIVE DRY CLUTCH ENGAGEMENT
2008
The dry clutch is a fundamental component in many automotive drivelines. For instance, the clutch torque transmissibility characteristic severely influences gearshift performance in automated manual transmissions. In this paper a novel model of the torque transmissibility of dry clutches is proposed. The dependence of the transmissibility characteristic on wear, slip speed and friction pads geometry and the influence of the diaphragm spring, the flat spring and the torsional damper springs is taken into account and pointed out. The sensitivity of a clutch engagement control scheme with respect to the clutch characteristic uncertainties is analyzed.
Dynamic Demand and Mean-Field Games
2017
Within the realm of smart buildings and smart cities,\ud dynamic response management is playing an ever-increasing\ud role thus attracting the attention of scientists from different\ud disciplines. Dynamic demand response management involves a\ud set of operations aiming at decentralizing the control of loads\ud in large and complex power networks. Each single appliance\ud is fully responsive and readjusts its energy demand to the\ud overall network load. A main issue is related to mains frequency\ud oscillations resulting from an unbalance between supply and\ud demand. In a nutshell, this paper contributes to the topic by\ud equipping each signal consumer with strategic insight. In particu…
A ride comfort tyre model for off-highway vehicles
2014
Tyre modelling is a major challenge when using time domain multibody simulation models to evaluate ride comfort on off-highway commercial vehicles. Further, parameters for these big tyres are difficult to obtain and thus, commercial car tyre models are difficult to apply. In this research work, a simple vertical tyre model for off-highway ride comfort evaluation is suggested. A displaced volume approach has been developed and combined with the slip theory to yield a tyre model that can be characterised by only three parameters. Full scale measurements on a dump truck have been carried out. Force responses from measurements are compared to the simulation results. Acceleration responses and t…
Further results on mathematical models of vehicle localized impact
2010
Accepted version of an article published by IEEE. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works Published version:http://dx.doi.org/10.1109/ISSCAA.2010.5634041 In this paper, we propose a method of modeling for vehicle crash systems based on viscous and elastic properties of the materials. This paper covers an influence of different arrangement of spring and damper on the models? respons…
Innovative Vehicle-Trailer Connection for Yaw Stability Improvement
2014
As well known, dangerous conditions may occur for the lateral stability of the road vehicles on increasing the running velocity. While it is easy to make up for this drawback in the case of a vehicle alone, by a proper weight distribution, the unstable trend may worsen unfavourably for the vehicle-trailer configuration, imposing a very hard correction task to the driver, who has to cope with the development of two types of instability, exponentially divergent or swaying with increasing amplitude. The critical velocity depends on the geometrical and inertial characteristics of the car-trailer system, on the cornering stiffness of the tires and on the weight distribution among the axles. The …
Reproduction of kinematics of cars involved in crash events using nonlinear autoregressive models
2012
Vehicle crashworthiness can be assessed by the variety of methods - the most common and direct one is a vehicle crash test. Visual inspection and obtained measurements, such as car acceleration, are used to examine impact severity of an occupant and overall car safety. However, those experiments are complex, time-consuming, and expensive. We propose a method to reproduce car kinematics during a collision using a feedforward neural network to estimate the system by use of nonlinear autoregressive (NAR) models. Specifically, feasibility of applying neural networks with an NAR model to the analysis of experimental data is explored by application to measurements of a vehicle crash test. This mo…
Common and Domain-specific Metamodel Elements for Problem Description in Simulation Problems
2014
It is well known that the multi-agent system paradigm is well suited for modelling and developing simulations of complex systems belonging to several application domains. Simulation study aims at developing simulation models useful for representing, studying and analyzing entities and their behavior in a system according to specific purposes. With our work we are trying to understand what are the right elements to be considered and included in the description of a simulation problem. In order to root our resulting metamodel in the state of the art of multi-agent simulations we started from the study of twelve papers dealing with four different application domains: Crowd Dynamics, Traffic an…
Non-fragile sliding mode control for flexible air-breathing hypersonic vehicles
2012
The non-fragile sliding mode tracking control design problem for a flexible air-breathing hypersonic vehicles (FAHVs) is investigated in this paper. A linearized model is constructed with respect to a trim point for the nonlinear, dynamically coupled simulation model of the FAHVs with external disturbance, then a reference model is designed and a tracking error model is proposed. An integral sliding surface is designed, and then the non-fragile H ∞ controller design problem for the sliding mode dynamics is discussed. sufficient condition is derived for the existence of such a controller in the presence of unmatched disturbance. A SMC law is derived to guarantee the reachability of the speci…
Col : A Data Collection Protocol for Vanet
2012
International audience; In this paper, we present a protocol to collect data within a vehicular ad hoc network (VANET). In spite of the intrinsic dynamic of such network, our protocol simultaneously offers three relevant properties: (1) It allows any vehicle to collect data beyond its direct neighborhood (i.e., vehicles within direct communication range) using vehicle-to-vehicle communications only (i.e., the infrastructure is not required); (2) It tolerates possible network partitions; (3) It works on demand and stops when the data collection is achieved. To the best of our knowledge, this is the first collect protocol having these three characteristics. All that is chiefly obtained thanks…