tailieunhanh - MEMS Mechanical Sensors - Stephen Beeby Part 7

Tham khảo tài liệu 'mems mechanical sensors - stephen beeby part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 110 Mechanical Transduction Techniques Original position of actuator Direction of applied magnetic field --------------------- Figure An example of an in-plane magnetic actuator. After 14 . sensor and the instrument may not be apparent. Many of today s commercial devices have some form of electronic processing within the main sensor housing perhaps simple electronic filtering or more sophisticated digital signal processing. The terms intelligent and smart sensor have been used almost interchangeably over the past 20 years or so to refer to sensors having additional functionality provided by the integration of microprocessors microcontrollers or application specific integrated circuits ASICs with the sensing element itself. The interested reader is encouraged to read the texts by Brignell and White 15 Gardner et al. 16 and Frank 17 for a deeper insight into the field of smart sensor technologies. For consistency in this text we will adopt the term smart sensor to refer to a microsensor with integrated microelectronic circuitry. Smart sensors offer a number of advantages for sensor system designers. The integration of sensor and electronics allows it to be treated as a module or black-box where the internal complexities of the sensor are kept remote from the host system. Smart sensors may also have additional integrated sensors to monitor say localized temperature changes. This is sometimes referred to as the sensor-within-a-sensor approach and is an important feature of smart sensor technology. An example of a smart sensor system is depicted in Figure . Many physical realizations of smart sensors may contain some or all of these elements. Each of the main subsystems will now be described in more detail. The sensing element is the primary source of information into the system. Examples of typical sensing techniques have already been outlined in this chapter. The smart sensor may also have the ability to stimulate the sensing element to provide a self-test .