Relative speed sensor

Speed of flange b relative to flange a.

  • signal
  • rotational
  • Modelica Standard Library
  • 3 ports
BlockRelative speed sensorKindrelSpeedSensorLibraryRotational

Description

Measures the angular velocity of flange b relative to flange a, without transmitting torque. Use it to monitor slip across a clutch or twist rate across a spring.

Example

Rotational drivetrain A torque step drives a motor inertia through a 2:1 gear and a shaft spring into a damped load, with every rotational sensor.

Torque 1 N·mMotor 0.01 kg·m²Gear 2:1Shaft powerShaft torqueShaft 1000 N·m/radLoad 0.04 kg·m²Friction 0.1FrameMotor accelerationShaft twist rateLoad speed
In Gradara, select a Relative speed sensor block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:Torque sensorFixed (rotational)Torsion springTorsion damperInertia (ideal)Ideal gearTorque stepSpeed sensor (ideal)Acceleration sensorPower sensor (rotational)

Ports

Outputs 1

  • Δωw_relsignal · rad/s

    Relative angular velocity, in rad/s.

Conserving terminals 2

  • aflange_arotational

    Reference flange. No torque is exchanged.

  • bflange_brotational

    Measured flange. No torque is exchanged.

Equations

Modelica
w_rel = d(flange_b.phi − flange_a.phi)/dt
flange_a.tau = flange_b.tau = 0

Implementation

Modelica Standard Library 4.1.0Modelica.Mechanics.Rotational.Sensors.RelSpeedSensor
MSL documentation

See also

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