Defining Relative Targets

You can create targets that are relative to the current state of the device.

Unlike absolute targets, relative targets are applied relative to the existing state of the device. This is helpful when modeling an indexing table or a rotor which runs indefinitely without any travel limits.

For example, in a scenario where a robot is welding a series of Cartesian targets that are at a fixed relative offset from each other, you can create a single robot motion activity for the first target and run a loop containing a single robot motion that has a relative target to cover the remaining points.

Similarly, a rotor having only one revolute joint and four positions 90 degrees apart would require a separate task for each position. The ability to use relative targets allows you to create a single target that moves 90 degrees relative to its current state.

Before you begin: You have created a robot task with robot motion activities.
  1. Select Teach
  2. Select a robot or a task.
  3. In the Teach panel, select a robot motion activity.
  4. Select Teach Options

    The Teach Options dialog box is displayed.

  5. Under Target Reference, select Relative.
  6. Jog the robot to the first relative position.
  7. From the context toolbar, select Insert a Cartesian Target

    For a robot or device motion, the relative offset between the currently selected motion activity and the current state of the robot/device after jogging appears in the Relative Values dialog box. These values can be directly edited in the dialog box.

    Note: If the currently selected instruction is not a robot or device motion, the Relative Values dialog box will display all zero values. These values must be entered manually.

  8. Select to create the new motion activity with relative target.

    The new motion activity appears in the Activities list for the task.

    In many applications that benefit from the use of relative targets, you may want to run a loop containing the single robot motion activity having a relative target for a specific number of iterations, as shown below.