Torque Actuator (AB)

Ideal torque actuator that generates torque proportional to the input signal

Since R2026a

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Libraries:
Simscape / Foundation Library / Rotational / Sources

Description

The Torque Actuator (AB) block represents an ideal actuator that generates a specified torque regardless of the load or angular velocity at the connected ports. The actuator has a relative angle between its ports.

Connections B and F are angle-based rotational conserving ports. Specify the torque at physical signal port S. The torque acts from port B on port F. Positive torque drives port F in the positive direction. For positive relative angle, port F has a more positive angle than port B.

The block logs these variables:

• t — torque that port B applies to port F.

• w_rel — relative angular velocity between ports, $${\omega }_{\text{Rel}}={\omega }_{\text{F}}-{\omega }_{\text{B}}$$.

For more information, see Data Logging.

The relative angle between the actuator ports is $${\theta }_{\text{Rel}}={\theta }_{\text{F}}-{\theta }_{\text{B}}$$.

The block has no parameters. You specify the relative angle between the ports as an initial variable target.

Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

Examples

Interpreting Torque in the Angle-Based Rotational Domain

Describes how to interpret torques in a Simscape™ angle-based rotational network. It outlines the key concepts for understanding the signs of logged torques. It examines rotational spring systems driven by torque sources at different ends, as well as a rotational system of inertias, to illustrate the torque behavior.

• Open Live Script

Ports

Input

S — Control signal, N*m

physical signal

Physical signal input port for the control signal that drives the actuator. A positive signal at this port indicates that the torque at port F is greater than at port B.

Conserving

B — Base port

angle-based rotational

Angle-based rotational conserving port that represents the base connection.

F — Follower port

angle-based rotational

Angle-based rotational conserving port that represents the follower connection.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2026a