DETECTION OF CHANGE OF POSITION OF OBJECT AND GEAR FOR ITS REALIZATION Russian patent published in 1998 - IPC

FIELD: radio engineering, fire and burglar alarms. SUBSTANCE: method includes probing of space limited by separation of media by acoustic signal and reception of reflected signal. According to method signal presenting linear superposition of acoustic waves is received, its amplitude and phase characteristics are measured and used to define matrix of parameters corresponding to position of nodes and antinodes of standing acoustic wave. This matrix is memorized and change of position of object is judged by change of at least one parameter of matrix. Gear for realization of method has former of radiation signal, radiator of acoustic signal, meter, storage, mismatch calculator, unit making decisions. Output of former of radiation signal is coupled to input of radiator of acoustic signal. Receiver of acoustic channel is multichannel one and it can receive two acoustic signals as minimum. Meter measures amplitude and phase characteristics. Gear is supplemented with calculator of matrix of state of acoustic field and calculator of reference matrix of state of acoustic field. Output of meter is coupled to input storage through calculator of reference matrix of state of acoustic field and to second input of mismatch calculator through calculator of matrix of state of acoustic field. EFFECT: increased functional reliability and stability. 10 cl, 11 dwg