simscape.multibody.JointActuationDictionary Class

Namespace: simscape.multibody

Dictionary that store joint primitive actuations

Since R2024a

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Description

Use an object of the simscape.multibody.JointActuationDictionary class to store joint actuations to apply to a compiled multibody model. The object functions like a dictionary in that you can store joint primitives and their corresponding actuations as key-value pairs. The keys are the paths of the joint primitives. To construct actuation forces and torques, use these classes:

Class Attributes

Sealed
true
ConstructOnLoad
true
RestrictsSubclassing
true

For information on class attributes, see Class Attributes.

Creation

Description

dict = simscape.multibody.JointActuationDictionary creates a default joint actuation dictionary.

You can use dict(keys) = Values to pair an actuation force or torque with the path of corresponding joint primitive as the key-value pair. If you assign multiple values to the same key, the last value you assign overwrites the previous values of the key.

Examples

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  1. Create a joint actuation dictionary.

    dict = simscape.multibody.JointActuationDictionary

    dict = 

  JointActuationDictionary with no actuations.

  2. Construct actuations for the desired joint primitives. Create a force of 5 N for a prismatic joint primitive, a torque of 10 N*m for the revolute joint primitive, and a torque of [3 4 5] N*m for a spherical joint primitive.

    force = simscape.multibody.PrismaticPrimitiveActuationForce(...
                     simscape.Value(5,"N"));
torque_r = simscape.multibody.RevolutePrimitiveActuationTorque(...
                     simscape.Value(10,"N*m"));
torque_s = simscape.multibody.SphericalPrimitiveActuationTorque(...
                     simscape.Value([3 4 5],"N*m"));

  3. Use the dict dictionary to store the force and torque for the joint primitives as key-value pairs. The keys are the paths of the joint primitives.

    dict("Pg/Pz") = force;
dict("Ri/Rz") = torque_r;
dict("Ro/S") = torque_s

    dict = 
  JointActuationDictionary with actuations:

  RevolutePrimitiveActuationTorque:

  Primitive Path  Value  Unit
  ______________  _____  ____

  "Ri/Rz"         10     N*m 

  PrismaticPrimitiveActuationForce:

  Primitive Path  Value  Unit
  ______________  _____  ____

  "Pg/Pz"         5      N   

  SphericalPrimitiveActuationTorque:

  Primitive Path  Value    Unit
  ______________  _______  ____

  "Ro/S"          [3 4 5]  N*m

    You can change the force and torque. For example, to replace the actuation torque for the Ri joint primitive with a new torque, enter:

    torque_r_new = simscape.multibody.RevolutePrimitiveActuationTorque(...
                     simscape.Value(-5,"N*m"));
dict("Ri/Rz") = torque_r_new

    dict = 
  JointActuationDictionary with actuations:

  RevolutePrimitiveActuationTorque:

  Primitive Path  Value  Unit
  ______________  _____  ____

  "Ri/Rz"         -5     N*m 

  PrismaticPrimitiveActuationForce:

  Primitive Path  Value  Unit
  ______________  _____  ____

  "Pg/Pz"         5      N   

  SphericalPrimitiveActuationTorque:

  Primitive Path  Value    Unit
  ______________  _______  ____

  "Ro/S"          [3 4 5]  N*m

Version History

Introduced in R2024a

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See Also

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