Haptic steering support for driving near the vehicle’s handling limits; skid-pad case

Current vehicle dynamic control systems from simple yaw control to high-end active steering support systems are designed to primarily actuate on the vehicle itself, rather than stimulate the driver to adapt his/her inputs for better vehicle control. The driver though dictates the vehicle’s motion, and centralizing him/her in the control loop is hypothesized to promote safety and driving pleasure. Exploring the above statement, the goal of this study is to develop and evaluate a haptic steering support when driving near the vehicle’s handling limits (Haptic Support Near the Limits; HSNL). The support aims to promote the driver’s perception of the vehicle’s behaviour and handling capacity (the vehicle’s internal model) by providing haptic (torque) cues on the steering wheel. The HSNL has been evaluated in (a) driving simulator tests and (b) tests with a vehicle (Opel Astra G/B) equipped with a variable steering feedback torque system. Drivers attempted to achieve maximum velocity while trying to retain control in a circular skid-pad. In the simulator (a) 25 subjects drove a vehicle model parameterised as the Astra on a dry skid-pad while in (b) 17 subjects drove the real Astra on a wet skid-pad. Both the driving simulator and the real vehicle tests led to the conclusion that the HSNL assisted subjects to drive closer to the designated path while achieving effectively the same speed. With the HSNL the drivers operated the tires in smaller slip angles and hence avoided saturation of the front wheels’ lateral forces and excessive understeer. Finally, the HSNL reduced their mental and physical demand.     

Application of slim A-pillar to improve driver’s field of vision

The importance of vehicle safety cannot be exaggerated in today’s mobile societies. Many manufacturers, associates related to vehicles and universities make an effort to improve vehicle safety by developing new technologies, applying high strength steel to the body structure etc. However, the majority of these efforts are focused on decreasing injury. It is absolutely important to minimize injury, but a more important aspect is coping with vehicle accidents. That is, As undeniably important as it is to minimize potential injuries, it is critical that experts focus on developing ways to keep drivers out of situations likely to lead to crashes in the first place. The purpose of this paper is to determine what the most critical factor is when coping with an unfamiliar driving situation. The answer is to provide a wide-open field of vision, especially for the driver. The driver’s field of vision is obstructed by the vehicle’s A-pillar. To solve this, the A-pillar obstruction angle, which is the angle between the driver’s eyes and the A-pillar should be decreased. This paper purposes three-methods for decreasing this angle structurally and applying a slim A-pillar which is as the best solution to decrease the A-pillar obstruction angle and ensure the drivers field of vision at the same time     

Experimental approach to developing human driver models considering driver’s human factors

A new approach to develop human driver models (HDMs) is proposed in accordance with the drivers’ generic human factors, i.e., gender, age, and experience, to develop more realistic vehicle simulations. The HDMs consist of three independent and stepwise models with functioning driver’s information processing stages based on the human factors: constructing drivers’ preview distance (PVD) models as a ‘cognition process’, implementing a finite preview optimal control algorithm as a ‘decision process’, and differentiating an ‘operation process’ according to neuromuscular efficiency. Eight different groups of 65 drivers with a 2 × 2 × 2 within-subject design participated in both the PVD estimates and neuromuscular efficiency tests to develop a set of statistically different HDMs. Regarding the preview distance models, an analysis of covariance (ANCOVA) procedure was adopted with two covariates (i.e., vehicle velocity and road curvature), while analyses of variance (ANOVAs) were performed on the neuromuscular efficiency parameters. The ANCOVA procedure produced eight significantly different cognition processes, whereas the ANOVAs revealed gender differences for the drivers’ neuromuscular systems. Moreover, an integrated vehicle simulation was configured with the HDMs using Carsim and Simulink software to observe the differential effects of both the cognition and operation processes on a double-lane-change (DLC) maneuver. During the simulations, gender differences in real-world DLC tests were also identified, especially between the male-oldexpert and the female-young-novice HDMs. The results presented in this study suggest that differentiating HDMs according to human factors is an essential process when utilizing vehicle simulations in the early stage of developing an intelligent vehicle system.     

China’s commercial vehicle market to witness a new round of development phase

China’s auto industry started in the commercial vehicle field and it kept giving impetus to the auto market until 2004. Statistics from the CAAM show that during the 1998 to 2004 period, the average annual growth rate of the field was 14.38 percent, high…     

Computational model for analyzing the kinematics and compliance characteristics of a commercial vehicle’s front suspension system

This paper develops a computational model that can analyze the kinematics and compliance characteristics of the front suspension of a commercial vehicle. This computational model is called the flexible multi-body dynamic model because it is developed by interfacing the finite element model of the multi-leaf spring with the dynamic model of the front suspension. In this paper, the bump mode and roll mode tests are performed with a suspension parameter measuring device (SPMD). An excitation load for creating the bump mode and roll mode motion is applied on the left and right tires slowly in in-phase and out-of-phase modes. In the test, wheel rate, toe angle change, caster angle change, and camber angle change, which together represent the wheel alignment, are measured along with the longitudinal and lateral wheel center loci which together represent the wheel center trajectory change. The reliability of the developed computational model is verified by comparing the simulation results with the SPMD test results. The developed flexible multi-body computational model will provide useful information on kinematics and compliance characteristics in the earliest stages of the commercial vehicle design process.     

From Offline to Adaptive Online Energy Management Strategy of Hybrid Vehicle Using Pontryagin’s Minimum Principle

This paper details the development of an energy management strategy (EMS) for real-time control of a multi hybrid plug-in electric bus. The energy management problem has been formulated as an optimal control problem in order to minimize the fuel consumption of the bus drivetrain for a typical day of operation. Considering the physical characteristics of the studied hybrid electric bus and its well-known daily tour, the Pontryagin’s minimum principle (PMP) is firstly used as the mean to obtain offline optimal EMS. Afterward, in order to adapt the proposed strategy for real-time implementation, the proposed control parameters are adapted online using feedback from the battery state of energy (SOE) which allows us to accurately control the battery SOE in the presence of wide range of uncertainties. The work proposed in this paper is conducted on a dedicated high-fidelity dynamical model of the hybrid bus, that was developed on MATLAB/TruckMaker software. The performance evaluation of the proposed strategy is carried out using a normalized driving cycles to represent different driving scenarios. Obtained results show that among the investigated methods, it is reasonable to conclude that the proposed adaptive online strategy based on PMP is the most suitable to design the targeted EMS.     

An analysis of driver’s steering behaviour during auditory or haptic warnings for the designing of lane departure warning system

We found that the steering vibration was effective for warning of lane-departure situations, especially when drivers did not know the meaning of warnings. It seems that many drivers have their own Mental Model for response to a haptic stimulus transmitted through the steering wheel. This mental model causes drivers to think that the vehicle is deviating from the lane when steering vibration was used as the warning signal. We can conclude that the mental model for the warnings should make interpreting vehicle conditions easy, especially when the haptic warning is transmitted through the steering wheel.     

International Forum on the Development of China’s Auto Industry 2005 to be held in Tianjin in September

The Forum, jointly sponsored by CATARC, SAE China and Tianjin Economic and Development Area (TEDA), will be held from 24 to 25 Sept. After years of rapid development, the automotive industry has become more and more mature. To meet the demand of automakers and guided by relevant government departments, CATARC and SAE China have jointly organized a Forum, to offer an arena for the relevant organizations, businesses and participants home and abroad. The Forum is aimed at promoting t…