Search Results

Accurate information of the absolute speed of a vehicle, when available, can be vital in simplifying the control laws of an anti-lock braking system (ABS) and auto-traction system (ATS). A current meter for measuring the speed of a vehicle is to multiply the measured wheel rotation rate to the wheel radius. The approach often includes abrupt unpredictable errors due to slip and skid of wheels and a biased error due to the steady state slip. These errors are sources of difficulty in the implementation of an ABS that is based on the absolute speed of the vehicle. This paper describes an accurate rule-based Kalman filtering technique for estimating the absolute speed of a vehicle. The enhanced accuracy is achieved by employing an additional accelerometer to complement the wheel speed-based speedometer. The accelerometer measures the acceleration of the vehicle in its forward direction and may be corrupted as well by high frequency noise.

Voltage and current surges are a major concern when it comes to ensuring the functional integrity of electrical and electronic components and modules in an automobile system. This paper presents a computer simulation study for analyzing the effect of high voltage spikes and current load dump on a new Integrated Driver/Receiver (IDR) IC, currently being developed for a J1850 Data Communication Bus in an automobile. It describes the modeling and simulation of the protection structure proposed for the device. The simulation study yields a prediction of current and voltage capability of the protection circuit based on thermal breakdown and transient responses of the circuit. Two levels of modeling, namely, the behavioral level model and the component level model, are used to generate the simulation results. Experimental data will be acquired and used to validate the simulation model when the actual device becomes available.

This paper describes a fuzzy logic (FL) approach to the design, implementation, and tuning of an expert knowledge-based TCS for a four-wheel drive vehicle. Military and commercial mutual interests in TCS technology are highlighted as the underlying motivation for this government, industry, academia cooperative program. Coordinated parallel efforts to model the TCS equipped vehicle and to perform basic on-vehicle TCS experiments provided additional information to augment the knowledge obtained from a study of commercial TCSs and the tire traction literature. The general traction control problem is discussed along with the hardware considerations for a TCS. The design and integration of the resulting FL-based TCS are described along with a representative sample of the test results documenting the system's performance.

The Intelligent Ground Vehicle Competition (IGVC) is a multidisciplinary exercise in product realization for college engineering students. They design, build, and compete with autonomous vehicles in events ranging from lane following, obstacle avoidance, platooning, to Global Positioning System (GPS) navigation. Technologies involved include electronic controls, computer-based vision systems, object detection, rangefinding, and global positioning. The real world applications are in intelligent transportation systems, the military, and manufacturing automation. Students have been creative and have learned a great deal. Industry recruiters have been highly supportive.

The Wavelet Transform (WT) has been developed two decades ago, and has since then been put to use in an increasingly wide array of applications. The WT provides a time-scale analysis of a signal. Compared to the widely-popular Fourier Transform (FT), originally developed two hundred years ago, the WT provides the time-evolution of the signal at different scales. The Discrete Wavelet Transform (DWT) is a computationally efficient implementation of the WT, in which the time-scale analysis is performed on a dyadic scale. The DWT is very suitable for knock detection systems, since it can provide the history of the knock signal at discrete scales within a crank angle window. It allows for the extraction of a multitude of features from the time-scale plane. Moreover, the DWT is suitable for real-time knock detection implementations on engine control units.

Embedded systems continue to become more complex. As a result, more companies are utilizing model-based design (MBD) development methods and tools. The use of MBD methods and tools is helpful in increasing time to market and having instant feedback on the system design. One area that continues to mature is the testing and verification of the MBD systems. This paper introduces a hybrid approach to functional tests. The test system is composed of simulation software and real-time hardware. It is not always necessary to test a system in a real-time environment, but it is recommended if the goal is to deploy the system to a situation that requires real-time response. Vehicle drive cycles and powertrain control are utilized in this research as the example test case for this paper. In order to test the algorithms on a real-time system, it is necessary to understand the target controller's computing limitations and adjust the algorithms to meet these limitations.

A 24 degree-of-freedom full vehicle-driving simulator is proposed in this paper. The simulator provides a full immersive graphical virtual scenery and force/motion feedback cues for the driver. The simulator has been developed to provide an open architecture in a local network environment. Using Matlab/Simulink one can interface with the vehicle model through this environment, designing and testing vehicle sub models while evaluating the ride performance of the vehicle. The development and implementation of a rollover detection and warning system is discussed, to illustrate the application of the driving simulator.