Background and Development
Multi-sensor integration is a system-controlled process based on integrating information from different sensors when a multi-sensor system completes a task. It emphasizes the conversion of different data and the overall flow structure for the system. Multi-sensor fusion is a specific stage in the process of multi-sensor integration, in which sensor information is merged into unified comprehensive information. The specific methods and procedures of data conversion and merger are emphasized.
Multi-sensor integration and fusion technology is actually a comprehensive technology of multi-source information. In multi-sensor integration and fusion, the most consistent estimate of a measured object and its nature are obtained through analysis and comprehension for data information from various sensors.
Multi-sensor fusion research started as early as 1973, when research institutions in the United States, funded by the Department of Defense, started to study sonar signal understanding systems. From then on, multi-sensor fusion technology developed rapidly. Apart from being used in the C3I (Command/Control/Communication Intelligence) system, many kinds of sensors are now widely used to gather information in industrial control, robotics, air traffic control, marine surveillance and management Multi-sensor fusion research has become an issue of concern in the military, production and high-technology development areas.
In 1988, the U.S. Department of Defense listed the C3I multi-sensor fusion technology as one of 20 key technologies of research and development in the 1990s. The C3I expert group led by the U.S. Secretary of Defense set up a specialized data fusion group and organized a number of thematic plans to study multi-sensor fusion technology, and since 1992 some 100 million U.S. dollars annually have been invested in multi-sensor fusion technology. Related journals are also published and specialized conferences are held internationally, so that there is a well researched environment for multi-sensor fusion technology. In October 1994, the first international conference on multi-sensor fusion and integration for intelligent systems, launched by IEEE, was held in Las Vegas (Dasarathy B.V., 1997). It signals that research and application of multi-sensor integration and information fusion have come into prominence.
Multi-sensor fusion theory is divided into numerical approach research of similar information fusion, and symbol approach research of information integration of different types. Numerical approach research of similar information fusion, especially distribution of all kinds of optimal, sub-optimal or part dispersed algorithms, is more dominant, while symbol approach research of information integration of different types is more difficult in theoretical research mainly oriented to exploratory research. There are many application systems with the feature of multi-sensor information integration, such as the early warning integrated navigation system, using INS, or Inertial Navigation System and the Global Positioning System (GPS) to improve accuracy by multi-sensor data fusion.