Method and apparatus for measuring phase
US4630033A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1983 |
| Grant date | Dec 16, 1986 |
| Priority date | — |
| Expiry date | Mar 25, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/645
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An angle transducer includes input rotor and reference rotor assemblies that are mounted for rotation upon a common shaft and that cooperate with respective moveable input stator and fixed reference stator assemblies to produce signals whose phase difference represents an input angle. Diametrically opposed sensors in each stator assembly achieve enhanced eccentricity error reduction by producing separate signals whose phases are averaged after the phase of each is individually measured. A phase measurement technique does not rely upon the mechanical accuracy of the angular placement of the poles for the rotor assemblies. A phase measurement between two signals is performed by beginning on an arbitrary zero crossing of the signal from the reference stator and forming, for each rotor, the sum of the times for the zero crossings for one complete revolution. To avoid the effects of crosstalk the rotors may have different numbers of poles. The sums, the different numbers of poles, the time for one revolution, and, for each rotor, the number of poles from the pole corresponding to the first term in the associated sum to an absolute reference pole, are the variables in a phase formula pro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.