Speed Measurement

Compute speed from rotor angular position

  • Library:
  • Motor Control Blockset / Sensor Decoders

Description

The Speed Measurement block calculates the angular speed from the angular position of the rotor by calculating the change in the angular position with respect to time.

Ports

Input

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Angular position of the rotor specified in either radians, degrees, or per-unit.

Data Types: single | double | fixed point

Output

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Angular speed that the block computes based on the angular position input.

Data Types: single | double | fixed point

Parameters

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Unit of the angular position θ.

The speed calculation method used in the block. The selected method determines the range of the rotor speed that the block can measure.

These parameters change values according to the Speed calculation criteria parameter:

Parameter nameMaximum application speedSpeed ResolutionTime interval for speed calculation

Delays for speed calculation (number of samples)

299

2828

Maximum measurable speed (RPM)

1000

10344.827610713.2857

Measurable speed resolution (RPM)

4.6566e-07

4.9892e-064.9892e-06

The fixed time interval (in seconds) between every two consecutive instances of block execution.

These parameters change values according to the Block sample time (S) parameter value:

  • Delays for speed calculation (number of samples)

  • Maximum measurable speed (RPM)

  • Measurable speed resolution (RPM)

The maximum rotor speed (in rotations per minute) that the block can measure.

These parameters change values according to the Maximum application speed (RPM) parameter value:

  • Delays for speed calculation (number of samples)

  • Maximum measurable speed (RPM)

  • Measurable speed resolution (RPM)

Dependencies

To enable this parameter, set Speed calculation criteria to Maximum application speed.

The minimum value of the θ input that the block can detect.

These parameters change values according to the Speed Resolution (RPM) parameter value:

  • Delays for speed calculation (number of samples)

  • Maximum measurable speed (RPM)

  • Measurable speed resolution (RPM)

The number of samples of the angular position input that the block measures to compute the average position value.

These parameters change values according to the Delays for speed calculation (number of samples) parameter value:

  • Maximum measurable speed (RPM)

  • Measurable speed resolution (RPM)

Dependencies

To enable this parameter, set Speed calculation criteria to Time interval for speed calculation.

Unit of the angular speed output.

The data type of the angular speed output .

Note

The Speed Measurement block may occasionally display the warning message 'Wrap on overflow detected.'

Introduced in R2020a