Resolver

Sine–cosine resolver: the sine and cosine of the electrical angle p·φ, and their negatives.

  • signal
  • rotational
  • Modelica Standard Library
  • 5 ports
  • 1 parameter
BlockResolverKindresolverLibraryMachines

Description

A sine–cosine resolver on a shaft: it outputs the sine and cosine of the electrical angle p·φ, and their negatives, as ideal unit-amplitude signals. It exerts no torque on the shaft.

Example

Resolver and Hall sensor A shaft turning at 10 rad/s read by a resolver, a Hall sensor, and an angle sensor.

Shaft 10 rad/sResolverHall sensorShaft angle
In Gradara, select a Resolver block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:Angle sensorConstant speedElectrical angle sensor

Ports

Outputs 4

  • sinsignal

    sin θ.

  • cossignal

    cos θ.

  • −sinnsinsignal

    −sin θ.

  • −cosncossignal

    −cos θ.

Conserving terminals 1

  • shaftflangerotational

    Shaft to measure, rotational. Draws no torque.

Parameters

  • Pole pairsp1

    ≥ 1

    Number of pole pairs, an integer ≥ 1. Use 1 for a single-speed resolver.

Equations

Modelica
θ = p · flange.φ
sin = sin θ, cos = cos θ
nsin = −sin θ, ncos = −cos θ

Implementation

Modelica Standard Library 4.1.0Modelica.Electrical.Machines.Sensors.SinCosResolver
MSL documentation

Assumptions and limitations

  • No carrier excitation or demodulation: the outputs are the ideal envelopes.
  • θ is measured from the shaft’s angle at zero; there is no mounting-offset parameter.

Tips

  • Recover the angle from sin and cos with a two-argument arctangent.

See also

Select a block in Gradara and press F1 to open its page offline.