Robust detection of strain with temperature correction
US7362096B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2005 |
| Grant date | Apr 22, 2008 |
| Priority date | — |
| Expiry date | Apr 18, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L1/127
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus (10) is set forth for measuring a return signal of a magnetostrictive sensor (20) that detects a force, torque, or pressure. The return signal includes noise, a DC resistance (44), an AC resistance and an inductance and the inductance is shifted ninety degrees from the AC resistance. The apparatus (10) includes a sensor filter (22) to remove the noise from the return signal. A sensor filter (22) shifts the return signal and more specifically, the inductance by an additional angle and the sum of the additional angle and the ninety degrees phase shift is defined as the final detection angle. To detect the inductance at the final detection angle, a wave filter (16) and a reference filter (28) shifts a reference signal by the final detection angle to trigger a first demodulator (26) to detect the inductance at the final detection angle. The inductance detected by the first demodulator (26) varies due to temperature. To remove the temperature from the measured inductance, the apparatus includes a DC detection circuit (42) to detect the DC resistance which is proportional to the temperature across the sensor (20). The DC resistance and the measure inductance are inserted int…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.