Capacitive Human-detection Systems with Auto-calibration

摘要

Three different capacitive human-detection systems for humancomputer interfacing or for protecting critical infrastructures have been presented. These systems can detect the position of a person as well as its direction of movement. The detector principles are based on the measurement of changes of capacitances between electrodes, which are affected by the location of a human-body. The detector systems can easily be camouflaged in a natural environment and they can be built with simple material, available in the consumer market. For the purpose of rapid evaluation of the features of the various systems, draft models based on several simplification and assumptions have been developed. The three detector systems work with a common interface, which use the three-signal auto-calibration technique, which eliminates the effects of additive and multiplicative errors of the electronic circuitry. Finally, an overall system calibration is applied for standardization of the output of each detector independently of its installation. Experimental results have been presented and a comparison of the features of the various systems has been made.