METHOD AND APPARATUS FOR CAPACITIVE DETECTION OF OBJECTS Russian patent published in 2013 - IPC G01R27/26 

FIELD: physics.

SUBSTANCE: apparatus for capacitive detection of objects has a capacitive sensor, having a sensitive capacitor formed between first and second capacitive elements, a voltage source, first and second switches, a storage capacitor, a switch control unit, a unit for controlling voltage across storage capacitors, a controller which facilitates measurement based on the rate of change of voltage across a storage capacitor and determining the position of the object. The sensor is a matrix containing multiple capacitive elements. The method for capacitive detection of objects involves performing steps for charging the sensitive capacitor by connecting to the voltage source with the storage capacitor disconnected from the voltage source; transferring charge from the sensitive capacitor to the storage capacitor; periodically repeating the processes of charging and transferring the accumulated charge; controlling voltage across the storage capacitor; determining at least one parameter which depends on the rate of change of voltage across the storage capacitor; determining the position of the object; determining the difference between the first measurement, which corresponds to the first capacitance value of the sensitive capacitor, and the second measurement, which corresponds to the second capacitance value of the sensitive capacitor. The sensitive capacitor is placed such that the distance between its surface and the floor surface is less than or equal to 50 mm.

EFFECT: high measurement accuracy.

14 cl, 18 dwg