Refine Your Search

Topic

Search Results

Viewing 1 to 19 of 19
Technical Paper

Research on the Dynamic Integration Control for Distributed-Traction Electric Vehicle with Four-Wheel-Distributed Steering System

2018-04-03
2018-01-0814
With rapid development of the automobile industry and the growing maturity of the automotive electronic technologies, the distributed-traction electric vehicle with four-wheel-distributed steering/braking/traction systems is regarded as an important development direction. With its unique chassis structure, it is the ideal benchmark platform used to evaluate active safety systems. The distributed-traction electric vehicle with four-wheel-distributed steering system is essentially full drive-by-wire vehicle. With its flexible chassis layout and high control degrees-of-freedom, the full drive-by-wire electric vehicle acted as a kind of redundant system is an ideal platform for the research of integrated control. In this treatise, the longitudinal dynamics of the electric vehicle as well as its lateral and yaw motions are controlled simultaneously.
Technical Paper

Control Synthesis for Distributed Vehicle Platoon Under Different Topological Communication Structures

2019-04-02
2019-01-0494
The wireless inter-vehicle communication provide a manner to achieve multi-vehicle cooperative driving, and the platoon of automotive vehicle can significantly improve traffic efficiency and ensure traffic safety. Previous researches mostly focus on the state of the proceeding vehicle, and transmit information from self to the succeeding vehicle. Nevertheless, this structure possesses high requirements for controller design and shows poor effect in system stability. In this paper, the state of vehicles is not only related to the information of neighbor vehicles, while V2V communication transmit information over a wide range of area. To begin with, the node dynamic model of vehicle is described by linear integrator with inertia delay and the space control strategy is proposed with different topological communication structures as BF, LBF, PBF, etc.
Technical Paper

Impact Theory Based Total Cylinder Sampling System and its Application

2008-06-23
2008-01-1795
A novel non-destroy repeatable-use impact theory based total cylinder sampling system has been established. This system is mainly composed of a knocking body and a sampling valve. The knocking body impacts the sampling valve with certain velocity resulting in huge force to open the sampling valve and most of the in-cylinder gas has been dumped to one sampling bag for after-treatment. The feasibility and sampling response characteristics of this impact theory based total cylinder sampling system were investigated by engine bench testing. Within 0 to 35°CA ATDC (Crank Angle After Top Dead Center) sample timing 50 percent to 80 percent of in-cylinder mass would be sampled, which was a little less compared with the traditional system. The half decay period of pressure drop was 10 to 20 degrees crank angle within 0 to 60°CA ATDC sample timing, which was about 2-3 times of the traditional system.
Technical Paper

Develop Hybrid Transit Buses for Chinese Cities1

2003-03-03
2003-01-0087
This paper summarized the first phase research work to develop hybrid transit buses for China, including driving cycle analysis, performance requirements setting, key components first dimensioning, configuration choosing, saving potential estimate and parametric study. Through these fundamental works, we realize that (1) the Chinese urban bus cycle has some specialties compared with foreign ones, and these specialties cause differences on the design criteria and design results of the hybrid buses; (2) the parallel configuration is better than the series one for the Chinese cycle from both fuel consumption and cost points of view.
Technical Paper

Performance Simulation Research on Bus with Air Suspension

2002-11-18
2002-01-3093
Air spring has a variable stiffness characteristic, its vibration frequency is much lower than that of leaf spring and will not vary with load of vehicle. More and more air springs are applied on automobile suspension. A study on the automobile ride comfort, and the controllability and stability about the bus with air suspension is performed in the paper, which is based on multi-body system dynamics.
Technical Paper

The Algorithmic Research of Multi-operating Mode Energy Management System

2013-04-08
2013-01-0988
The traditional energy management algorithm is mainly based on a single driving cycle, it is obvious that many factors might be often neglected by designer, such as different driving cycles would suit for different control strategies. But they tend to make decisions on the balance of torque distribution and battery power that based on a single driving cycle. Therefore, it is very difficult to achieve the optimal control in each case. In this paper we introduce a new design concept of Multi-operating mode energy management, a mathematical model of the energy management applied to a hybrid vehicle system is presented. Results of simulations using the model with the Multi-operating mode energy management were compared with results of simulations using a model with the single mode energy management, allowing the energy efficiency evaluation of the proposed energy management system.
Journal Article

Analysis of Performance Parameters of Torsional Vibration Damper Under Various Operating Conditions

2013-04-08
2013-01-1488
The performance parameters of torsional vibration damper, including stiffness and damping, have great influence on the torsional vibration of automobile driveline. At present, the research on torsional vibration damper mainly concentrates on the torsional stiffness, but rarely on the torsional damping characteristics. This paper systematically studied the effect of torsional stiffness and damping on torsional vibration of automobile driveline under uniform speed conditions, accelerated and decelerated conditions, idling conditions and resonance conditions. The requirements on stiffness and damping of various operating conditions were summarized. The effect and requirements researched were useful to performance match design of torsional vibration damper.
Journal Article

Objective Evaluation of Interior Sound Quality in Passenger Cars Using Artificial Neural Networks

2013-04-08
2013-01-1704
In this research, the interior noise of a passenger car was measured, and the sound quality metrics including sound pressure level, loudness, sharpness, and roughness were calculated. An artificial neural network was designed to successfully apply on automotive interior noise as well as numerous different fields of technology which aim to overcome difficulties of experimentations and save cost, time and workforce. Sound pressure level, loudness, sharpness, and roughness were estimated by using the artificial neural network designed by using the experiment values. The predicted values and experiment results are compared. The comparison results show that the realized artificial intelligence model is an appropriate model to estimate the sound quality of the automotive interior noise. The reliability value is calculated as 0.9995 by using statistical analysis.
Journal Article

System Design and Parameter Matching for the New Generation of Hybrid Electric City Bus

2008-06-23
2008-01-1573
In this paper, based on the research of the first generation of a hybrid electric city bus, principle researches have been offered on the parameters matching of the power-train and main components for the new generation of hybrid electric city bus. The vehicle system was designed integrated, and then simulation platform was developed and established. The dynamic and economy performance can be predicted based on the above work, results show that the designed hybrid electric city bus can meet the performance demands and validate rationality of the parameters matching.
Technical Paper

Lateral Stability Control Algorithm of Intelligent Electric Vehicle Based on Dynamic Sliding Mode Control

2016-09-14
2016-01-1902
A new lateral stability control method, which is based on vehicle sideslip angle and tire cornering stiffness estimation, is proposed to improve the lateral stability of the four-in-wheel-motor-driven electric vehicle (FIWMD-EV) in this paper. Through the lateral tire force information, vehicle sideslip angle can be estimated by the extended kalman filter (EKF). Using the estimated vehicle sideslip angle, tire cornering stiffness can be also estimated by forgetting factor recursive least squares (FFRLS). Furthermore, combining with the vehicle dynamics model, an adaptive control target model is proposed with the information on vehicle sideslip angle and tire cornering stiffness. The new lateral stability control system uses the direct yaw moment control (DYC) based on dynamic sliding mode is proposed. The performance and effectiveness of the proposed vehicle state estimation and lateral stability control system are verified by CarSim and Simulink cosimulation.
Technical Paper

Research of the Primary Breakup of a Planar Liquid Sheet Produced by an Air-Blast Atomizer

2014-04-01
2014-01-1430
The primary breakup of a planar liquid sheet produced by an air-blast atomizer was studied through numerical simulations, in order to reveal physical mechanisms involved during this process. The reliability of simulations was verified by comparing the macroscopic parameters, e.g. breakup time and spatial growth rate, with experimental data. Shear instability and RT (Rayleigh-Taylor) instability were found to play important roles during the primary breakup. By analyzing the acceleration of a fluid parcel within liquid sheet using Discrete Particle Method, and measuring the wave length of transverse unstable wave, RT instability was found to be partially responsible for transverse instability. The predictions of LISA (Linearized Instability Sheet Atomization) model on breakup time were compared to experiments, and obvious differences were found to exist.
Technical Paper

A Sliding Mode Observer for Vehicle Slip Angle and Tire Force Estimation

2014-04-01
2014-01-0865
In this paper, a sliding mode observer for estimating vehicle slip angle and tire forces is developed. Firstly, the sliding mode observer design approach is presented. A system damping is included in the sliding mode observer to speed the observer convergence and to decrease the observer chattering. Secondly, the sliding mode observer for vehicle states is developed based on a 7 DOF embedded vehicle model with a nonlinear tire model ‘UniTire’. In addition, since the tire lateral stiffness is sensitive to the vertical load, the load transfers are considered in the embedded model with a set of algebraic equations. Finally, a simulation evaluation of the proposed sliding mode observer is conducted on a validated 14 DOF vehicle model. The simulation results show the model outputs closely match the estimations by the proposed sliding mode observer.
Technical Paper

The Development of a Small Restricted Turbocharged Racecar Engine

2016-11-08
2016-32-0061
This paper summarized the development methodology and technical experiences on Formula Student racecar engines acquired by Jilin University from 2011 to 2015. This series of engines are all based on 600cc 4-cylinder motorcycle gasoline engines and were modified to turbocharged engines which met the Formula Student technical regulations, in order to achieve higher power output, wider torque band as well as lower fuel consumption. During the development process, multiple research projects have been conducted surrounding the turbocharging technology. These research projects have covered multiple areas including the matching of the flow rate characteristics of the engine and the turbocharger, the design of intake and exhaust systems, research on the wastegate as well as its actuator, the tuning and control of the boost pressure as well as the design of the lubrication system for the turbocharger, etc.
Technical Paper

Deterioration Characteristic of Catalyzed DPF Applied on Diesel Truck Durable Ageing

2018-09-10
2018-01-1701
In this paper, it was researched the degradation characteristics of catalytic performance of three kinds of DPFs (C1, C2 and C3, with precious metal concentrations being 15, 25 and 35 g/ft3 respectively) after diesel truck aging. It is found out that the crystallinity of three kinds of DPF samples (Used) in full vehicle aging was higher than that of fresh samples (Fresh) and aged samples (Aged) in the laboratory. Compared with Fresh samples, the concentration of Pt atom in precious metal on the surface of Aged and Used samples tends to decrease in most cases. Activities to CO and C3H8 of Aged and Used samples of three kinds of DPFs had all been degraded, and activity degradation showed a substantial correlation with concentration reduction rate of precious metal on the carrier surface. NO2 productivity of Used samples all rose. Crystallinity of DPF samples after full vehicle aging in Inlet, Middle and Outlet areas successively increased.
Technical Paper

Research on Roll Vibration Characteristics of a Truck's Front Suspension

2015-04-14
2015-01-0635
For the roll vibration problem of a Truck, a 4-DOF roll vibration model of its front suspension system was built. According to dynamics theory, the complex modal vibration modes of the model were all obtained. At the same time, the frequency response functions of frame roll angle acceleration, the relative dynamic load of wheel and the suspension dynamic deflection were respectively presented. Then their characteristics were respectively researched. In the process of characteristic analysis, a new system parameter was proposed, which is the space ratio of the space between suspensions of left and right sides and the wheel track of the front axle (space ratio in short). At last, the influence of system parameters on the vibration transmission property was also reserached, which included the natural frequency of the frame, the damping ratio, the stiffness ratio, the mass ratio, the rotational inertia ratio and the space ratio.
Technical Paper

Studies on Steering Feeling Feedback System Based on Nonlinear Vehicle Model

2017-03-28
2017-01-1494
The steer-by-wire system has been widely studied due to many advantages such as good controllability. In the system, the steering column is cancelled and the driver can't feel the feedback torque (also called steering feeling) coming from the ground. Therefore a steering feeling feedback system is needed. In this paper, we propose a simple method to calculate desired feedback torque based on a nonlinear 2DOF vehicle model. The vehicle model contains the nonlinearity of tire. So that the proposed method is also appropriate for big acceleration conditions. Besides that, the properties of steering system such as friction and stiffness are also taken into consideration. As for conventional steering system, driver can only feel part of the feedback torque due to the power assist system. In order to provide steering feeling similar to conventional steering system, a weighting function is proposed to compensate the influence of power assist system.
Technical Paper

A Nonlinear Slip Ratio Observer Based on ISS Method for Electric Vehicles

2018-04-03
2018-01-0557
Knowledge of the tire slip ratio can greatly improve vehicle longitudinal stability and its dynamic performance. Most conventional slip ratio observers were mainly designed based on input of non-driven wheel speed and estimated vehicle speed. However, they are not applicable for electric vehicles (EVs) with four in-wheel motors. Also conventional methods on speed estimation via integration of accelerometer signals can often lead to large offset by long-time integral calculation. Further, model uncertainties, including steady state error and unmodeled dynamics, are considered as additive disturbances, and may affect the stability of the system with estimated state error. This paper proposes a novel slip ratio observer based on input-to-state stability (ISS) method for electric vehicles with four-wheel independent driving motors.
Technical Paper

Control Optimization of a Charge Sustaining Hybrid Powertrain for Motorsports

2018-04-03
2018-01-0416
The automotive industry is aggressively pursuing fuel efficiency improvements through hybridization of production vehicles, and there are an increasing number of racing series adopting similar architectures to maintain relevance with current passenger car trends. Hybrid powertrains offer both performance and fuel economy benefits in a motorsport setting, but they greatly increase control complexity and add additional degrees of freedom to the design optimization process. The increased complexity creates opportunity for performance gains, but simulation based tools are necessary since hybrid powertrain design and control strategies are closely coupled and their optimal interactions are not straightforward to predict. One optimization-related advantage that motorsports applications have over production vehicles is that the power demand of circuit racing has strong repeatability due to the nature of the track and the professional skill-level of the driver.
Journal Article

GPS Modeling for Vehicle Intelligent Driving Simulation

2018-04-03
2018-01-0763
In recent years, intelligent vehicles have become one of the major research topics in vehicle engineering and have created a new opportunity for the automotive industry. Simulation and real experiment are both essential to the development of intelligent vehicle technologies. Vehicle positioning systems, such as global positioning system (GPS), play an important role in intelligent vehicle development. The GPS model plays a major part in the development of intelligent vehicle simulation systems. Primarily focusing on application requirements of intelligent vehicle simulation platforms for GPS sensor modeling, considering the major factors affecting positioning accuracy in vehicle driving environments, this article establishes a new GPS model and algorithm based on the physical and functional characteristics of GPS. As the basis of this model system, a precise ephemeris model is established to obtain the coordinates of GPS satellites at any given time.
X