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A joint connection between two links with kinematic and dynamic properties. Notice that a joint will always be between two links. The number of joints is equal to the number of links minus one.


  • Name: The name used when referring to this element from other places.

Mandatory children

  • origin: Transformation frame respect to the declared child's frame of reference
    • Var: smtk_transform
    • Type: constant
    • Default value: 0 0 0 0 0 0 1
    • Value labels: x y z qx qy qz qw
  • parent: The name of the parent link.
    • Var: smtk_link
    • Type: constant
  • child: The name of the child link.
    • Var: smtk_link
    • Type: constant
  • axis: Indicates the axis of the joint. Multiple space-separated values can be given.
    • Var: smtk_axis_array
    • Type: constant
    • Default value: fixed
    • Possible options: x, y, z, rx, ry, rz, fixed
  • initial_position: Default position for the joint. Multiple space-separated values can be given if more than one axis is used for the joint.
    • Var: smtk_vector
    • Type: input
    • default: 0
  • limits: Specifies a variety of limits for the joint.

Optional children

  • dynamics: Specifies a variety of dynamical properties of the joint

  • joint_sensor: This sensor can be used to detect properties of the current state of the joint.

  • joint_motor: The joint motor can be used to set the joint in motion.

  • override_iterations: It overrides the default constraint solver iteration value.

    • Var: smtk_int
    • Type: constant
    • default: 50