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The purpose of this paper is to develop and experimentally validate a practical and effective technique for the automatic regulation of a hydraulic semiactive vibration absorber (SAVA) for automobiles. The work relies on a consistent hydraulic model of the actuator dynamics that includes the effects of fluid compressibility and a nonlinear viscous loss characteristic. A bistate control algorithm is developed using a Lyapunov approach that seeks to dissipate the energy of the system. The performance of the proposed semiactive damper design on a quarter car model of an automobile suspension is established experimentally on a vibrating test stand. The work provides evidence that the inexpensive hardware design makes it possible to improve the ride and handling performance.

This paper presents a preliminary study of a sampling period decision for robust control of a distributed control system based on an in-vehicle network with three types of data (real-time synchronous data, real-time asynchronous data, and nonreal-time asynchronous data). The architecture of automotive systems is currently changing from a number of standalone electronic control units (ECUs) to a functionally integrated distributed system which is linked by a network. The control performance of the integrated networked control system can be changed by the characteristics of time delays among the application ECUs. A basic parameter for a scheduling method of the networked control systems, a maximum allowable delay bound is used, which guarantees stability of the networked control system, and it is derived from the characteristics of the given plant using presented theorems.

The performance of an integrated Vehicle Stability Control (VSC) system depends on not only control logic itself, but also the performance of state estimator and control threshold. In conventional VSCs, a control threshold is designed by vehicle characteristics and is centered on average drivers. A VSC algorithm with variable control threshold has been investigated in this study. The control threshold can be determined by phase plane analysis of side slip angle and angular velocity. Vehicle side slip angle estimator has been evaluated using test data. Estimated side slip angle has been used in the determination of the control threshold. The performance of the proposed VSC algorithm has been investigated by human-in-the-loop simulation using a vehicle simulator. The simulation results show that the control threshold has to be determined with respect to the driver steering characteristics.

We report a method to automatically generate test cases for automotive embedded software from a UML-based model using XML metadata interchange (XMI). First, the software model created using UML is converted to metadata in XMI format. Then, based on this metadata (which does not depend on a specific language), software test cases for structural testing or requirement-based testing may be generated using an appropriate parser. The model does not need to be implemented using the Object Constraint Language (OCL), and software test cases may be generated using an appropriately defined parser for a given language (which may be C/C++). Because software test cases can be converted to hardware test cases via a stimulus-mapping table, which contains the information on the digital and analog signals, and the communications interface, hardware test cases may also be generated automatically.

This paper presents a closed-loop evaluation of the Vehicle Stability Control (VSC) systems using a vehicle simulator. Human driver-VSC interactions have been investigated under realistic operating conditions in the laboratory. Braking control inputs for vehicle stability enhancement have been directly derived from the sliding control law based on vehicle planar motion equations with differential braking. A driving simulator which consists of a three-dimensional vehicle dynamic model, interface between human driver and vehicle simulator, three-dimensional animation program and a visual display has been validated using actual vehicle driving test data. Real-time human-in-the loop simulation results in realistic driving situations have shown that the proposed controller reduces driving effort and enhances vehicle stability.

Drivers’ physical and physiological states change with prolonged driving. Driving for extended periods of time can lead to an increased risk of low back pain and other musculoskeletal disorders, caused by the discomfort of the seats. Static and dynamic are the two main categories must be considered within the seating development. The posture and orientation of the occupant are the important factors on static comfort. Driving posture measurement is essential for the evaluation of a driver workspace and improved seat comfort design. This study evaluated the comfortable driving posture through physiological and ergonomics measurements of an automotive premium driver seat. The physiological evaluation includes electroencephalographic (EEG) for brain waves, Biopac’s AcqKnowledge program, and subjective measurements on 32 healthy individuals. JACK simulation was used for the ergonomics evaluation, i.e., the magnitude of the spinal loads about lumbar vertebrae was estimated.

Under the present effort to decrease of air pollution, Electric Vehicles (EVs) are appeared and developed. EVs are running by using electrical energy resource by supporting of battery packs. The effect of air-conditioning has proven to be a serious problem to the point of battery depleting. Thus in the present study, effects of air conditioning (i.e., cooling and heating) on driving range were studied for various driving modes including UDDS, HWFET, and NEDC. The result shows that EV energy efficiency is opposing the usual trend of internal combustion engine vehicle's fuel consumption in highway driving mode than urban driving mode. In highway mode, EV energy efficiency and driving range also decease than urban driving mode. This status was influenced on motor characteristic which torque decrease in high speed rotating conditions and highway driving mode consist of constant speed velocity so it couldn't use the regenerative braking system effectively.

FlexRay is a deterministic and fault-tolerant in-vehicle network(IVN) protocol. It is expected to become a practical standard for automotive communication systems. According to the FlexRay protocol specifications, there are about 60 configurable parameters which should be determined in the design phases. The parameters increase the complexities of FlexRay-based control system development. In this study, we are suggesting a formal design process for FlexRay-based control systems, which is focused on network parameter optimization. We introduce design phases from functional system models to implementations. These phases present formal ways for task allocation, node assignment, network configuration, and implementations. In the network configuration phase, two FlexRay core parameters are selected to optimize network design. Optimal methods of the core parameters provide concise guide lines for optimal communication cycle length and optimal static slot length.

In the extremely cost-sensitive and competitive automotive industry, manufacturers and suppliers are constantly searching for means to reduce both time-to-market and development costs. As a kind of solution to satisfy these requirements, Rapid-control prototyping (RCP) has established itself as viable technology, albeit not everywhere yet. One big gap in the development process, however, is the transfer form RCP to a target implementation with all its limitations. This paper presents a new RCP platform, which aims to provide a consistent environment both at the RCP step and at the target code implementation step. To achieve this goal, the proposed prototyping system is designed very similar to the real production ECU as much as possible, and it supports all the features, which are needed in the RCP.

Human drivers navigate by continuously predicting the intent of road users and interacting with them. For safe autonomous driving, research about predicting future trajectory of vehicles and motion planning based on these predictions has drawn attention in recent years. Most of these studies, however, did not take into account driver’s intentions or any interdependence with other vehicles. In order to drive safely in real complex driving situations, it is essential to plan a path based on other driver’s intentions and simultaneously to estimate the intentions of other road user with different characteristics as human drivers do. We aim to tackle the above challenges on highway merge scenario where the intention of other road users should be understood. In this study, we propose an intention aware motion planning method using finite state machine and model predictive control without any vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communications.

Electromechanical relays that are coupled with fuses have been used for controlling electrical loads in vehicles. In the past decade, semiconductor power switches have been developed for overcoming the physical limits of relays and fuses. Semiconductor power switches can not only replace relays and fuses but can also improve a system's reliability and efficiency. In this study, we introduce the Smart Automotive Switch (SAS), which is a smart high side power switch of Fairchild Korea semiconductor. Functional capabilities, such as power switching, protection and self-diagnosis of SASs are presented in case studies involving, for example, headlights, glow plugs, and fuel pump control systems. Through these experimental studies, the suitability of SASs is validated for designing improved automotive electronic control systems.

This paper presents the Matlab/Simulink-based Software-in-the-Loop Simulation (SILS) tool which is the co-simulator for temporal and functional simulations of control systems. The temporal behavior of a control system is mainly dependent on the implemented software and hardware such as the real-time operating system, target CPU and communication protocol. In this research, the SILS components with temporal attributes are specified as tasks, task executions, real-time schedulers, and real-time networks. Methods for realizing these components in graphical block representations are investigated with Matlab/Simulink, which is the most commonly used tool for designing and simulating control algorithms in control engineering. These components are modeled in graphical blocks of Matlab/Simulink.

Using quarter car model, an analytic method for performance estimation of a vehicle suspension system is presented and as the variables of performance estimation, frequency response, RMS response and performance index are considered. From frequency response function, compromise of response performance to the whole frequency range is verified and from RMS response and performance index, sensitivity of ride and handling characteristics are examined. Using full car model, sweet area (stable ride area) are determined and performance sensitivity is estimated according to the change of feedback gains. In order to estimate the output sensitivity, response curve is displayed using 3-dimensional and contour plot. Design data are suggested for optimal design parameter estimation, which maximize the performance of the given suspension system.

In this study, a Steer-by-Wire (SBW) controller was developed using the Hardware-In-the-Loop-Simulation (HILS) system. The mechanism of the HILS system consists of a hydraulic actuator for a lateral force on the front tires in a real vehicle. There are two motors in the SBW system controlled by one Electronic Control Unit (ECU). One motor in the steering wheel is to improve the driver's steering feel and the other motor in the steering linkage is to improve the vehicle maneuverability. The SBW controller's availability was verified through a number of simulations on the HILS system. The SBW fail-safe logic was tested through various simulations of the hazard environment on the HILS system. Consequently, the control logic of the SBW system was developed easily and safely in a laboratory.

An efficient development environments such as Software-in-the-Loop Simulation (SILS) and Rapid Control Prototyping (RCP) have been widely used to reduce the development time and cost of real-time ECUs. However, conventional SILS does not consider temporal behaviors caused by computation time, task scheduling, network-induced delays, and so on. As a result, the control performance of ECU is likely to be degraded after implementation. To overcome this problem, SILS/RCP which considers the temporal behaviors was suggested in the previous research. In this study, we validated the proposed SILS/RCP environments which are used to design an Electronic Stability Control (ESC) system which is one of the hard real-time control systems. The proposed SILS/RCP environments make it possible to realize ECUs in the early design phase by considering temporal behaviors.