ABSTRACT
Section 4.1 discusses sensors and sensing strategies. It explains that sensors use a wide spectrum of transducer and signal transformation approaches with corresponding variations in technical complexity. These range from relatively simple temperature measurements to the detection of specific bacteria species using sophisticated optical systems. The healthcare, wellness, and environmental domains use a variety of sensing approaches, including microelectromechanical systems (MEMS), as well as optical, mechanical, electrochemical, semiconductor, and biosensing systems.
Section 4.2 describes the various types of sensors in detail. It notes that vehicle autonomy and driver assistance systems rely on a balanced mix of technologies: radar (radio detection and ranging), LiDAR (light detection and ranging), cameras, and ultrasonic sensors. These technologies often have overlapping capabilities, but each has its own strengths and limitations. Section 4.3 discusses sensors used in missions, such as navigation sensors, and reviews the applications of sensors for missions.
Section 4.4 talks about autonomous vehicle technologies, specifically, localization and mapping. Vehicle self-localization is an important and challenging issue in driving assistance and autonomous driving research. This section investigates two methods used for vehicle self-localization: active sensor-based and passive sensor-based methods. Active sensor-based localization was first proposed for robot localization and introduced into autonomous driving more recently. The simultaneous localization and mapping (SLAM) technique is an active sensor-based localization method. A passive sensor-based localization technology is the Global Navigation Satellite System (GNSS).
Section 4.5 describes sensor fusion, sensor platforms, and the Global Positioning System (GPS). It notes that the sensor fusion techniques increase the reliability of measurement results by combining measurement results from multiple different sensors. Sensor platforms are a subset of smart sensors, and as smart sensors, they feature a microcontroller, a wired/wireless interface, and memory. Finally, the section defines a GPS as a system of satellites, computers, and receivers that is able to determine the latitude and longitude of a receiver on Earth by calculating the time difference for signals from different satellites to reach the receiver.
