Inductive sensor

About: Inductive sensor is a research topic. Over the lifetime, 2282 publications have been published within this topic receiving 21984 citations.

Logic for changing modes of operation of a touch and proximity sensor that can change sensitivity

Abstract: A system and method for changing a mode of operation of a touch and proximity sensor depending upon the strength of a signal from a detectable object relative to the touch and proximity sensor, wherein the system and method changes sensitivity of the touch and proximity sensor by switching between discrete sensitivity modes of operation as the distance of the object in a three dimensional volume of space above the touch and proximity sensor changes, to thereby enable the touch and proximity sensor to accurately detect and the track a presence of one or more objects.

Rotational sensing with inductive sensor and rotating axial target surface

Abstract: A rotational sensing system is adaptable to sensing motor rotation based on eddy current sensing. An axial target surface (20) is incorporated with the motor rotor (15), and includes one or more conductive target segment(s) (21A, 21B, 23A, 23B). An inductive sensor (30) is mounted adjacent the axial target surface (20), and includes one or more inductive sense coil(s) (31 A, 31B, 33A, 33B), such that rotor rotation rotates the target segment(s) (21 A, 21B, 23A, 23B) laterally under the sense coil(s) (31 A, 31B, 33A, 33B). An inductance-to -digital converter (IDC) (50) drives sensor excitation current to project a magnetic sensing field toward the rotating axial target surface (20). Sensor response is characterized by successive sensor phase cycles that cycle between LMIN in which a sense coil is aligned with a target segment, and LMAX in which the sense coil is misaligned. The number of sensor phase cycles in a rotor rotation cycle corresponds to the number of target segments (21A, 21B, 23A, 23B). The IDC (50) converts sensor response measurements from successive sensor phase cycles into rotational data.

Design and implementation of an inductive-based human postures recognition system

Abstract: This paper describes the design andimplementation of an inductive-based human postures recognition system during Muslim prayers or ‘Solat’. Inductive sensors are preferred over contact sensors as they allow remote detection of postures. An array of inductive sensors are placed underneath a prayer mat to sense four different postures namely Woquf, Rokoo, Sojod and Qood. Each inductive proximity sensor comprises of a modified inductive loop, with inner and outer loops and three capacitors. The design of the sensing circuit was simulated using both MATLAB and Multisim. Nine identical sensors, with each sensor placed on a different zone on the prayer mat, are connected in parallel to a ChipKit Max32 development board. The sensors send analog signals that are digitized by the board and sent to a PC as frequency plots. Posture identification was done by analyzing the triggered zones. Experimental results are in agreement with both the analytical and simulation results and can successfully distinguish the different postures remotely.

Inductive proximity sensor

Abstract: Inductive proximity sensor for detecting an object (3) having electrical conductivity comprising a sensor housing, a measuring coil (L1) and reference coil (L2) placed on either side of a plane of symmetry (10) through the sensor housing. Each coil (L) is partly surrounded by a piece of magnetic material (8) which leaves the measuring coil (L1) or reference coil (L2) respectively free at the front which faces the direction of the object (3) to be detected or a reference member (9). An electronic circuit is provided for supplying both coils (L) with an AC signal and for measuring the change in a specific property of the measuring coil (L1) with respect to that of the reference coil (L2) when an object (3) approaches and determining therefrom the distance (d1) or the presence of the object (3). The pieces of magnetic material (8) around the two coils (L) are formed essentially from the same homogeneous material forming a block. Means (4) are provided in the sensor housing for screening magnetic fields produced by both coils (L) in order to suppress thereby mutual crosstalk. The electronic circuit for each coil has a separate synchronous detector with its own oscillator for effecting a frequency-selective measurement such that the effect of changes in the properties of the magnetic material and of the measuring coil on the detection distance is compensated for electronically. Both oscillators of the synchronous detectors have a frequency offset from each other.