A Cost-Effective Ultrasonic Sensor-Based Driver-Assistance System for Congested Traffic Conditions

摘要

In urban areas, congested traffic results in a large number of accidents at low speeds. This paper describes an accurate and fast driver-assistance system (DAS) that detects obstacles and warns the driver in advance of possible collisions in such a congested traffic environment. A laboratory prototype of the system is built and tested by simulating different weather conditions in the laboratory. The proposed DAS is also suitable as a parking-assistance system. Ultrasonic sensors are used to detect obstacles in this paper because they have several advantages over other types of sensors in short-range object detection. Multiple sensors are needed to get a full-field view because of the limited lateral detectable range of ultrasonic sensors. Furthermore, crosstalk is a common problem when multiple ultrasonic sensors are used. A simple microcontroller-based method to reduce crosstalk between sensors is described, which is achieved by firing each transducer by a pseudorandom number of pulses so that the echo of each transducer can uniquely be identified. Existing DASs need more time to reliably detect the objects, making them unsuitable for DASs, where time is a critical factor. A method to reduce the obstacle detection time of the system is also proposed. The cost of this high-performance system is expected to be very reasonable. All the practical implementation details are included. Extensive experimentation has been carried out, and the results confirm the speed and reliability of the presented system.