Using the Reach Envelope

ascenari.gif (1364 bytes) This procedure describes how to use the powerful reach envelope creation tool. This tool takes advantage of the manikin's inverse kinematics (IK) capability to evaluate the manikin's arm reachability in the 3D space. It is particularly useful in facilitating product design and review.
A reach envelope is a surface that represents all the possible positions the manikin can reach using only the arm and forearm. The motion starts at the shoulder.
  • You can create two reach envelopes: one each for the right and left hand.
  • The reach envelope is included in the clash detection algorithm.

In order to offer a suitable workplace planning solution, there is also the generation of reach envelopes of both hands for 3 specific ranges:
1. Ideal (short) reach envelope;
2. 90% reach envelope;
3. Extended reach envelope (with body assistance).

See:
Reach Envelope
Ideal (short) reach envelope for V5 Human
Physiologically maximal (90%) reach envelope for V5 Human
Extended reach envelope (includes spine bending with body assistance)
 

Reach Envelope

  1. Create a new manikin or insert one from the samples directory.

  2. Select the Reach Envelope .   Then you are prompted to select manikin or manikin a segment.

    • Scenario 1  The selected manikin that has already a reach envelope.
      No matter the segment on which the user clicks, the selected segment is the one of the existing reach envelope. Then, the new panel appears with the current settings.
    • Scenario 2 The selected manikin doesn’t have any reach envelope.  If you click on any upper body segment (except the fingers) directly in the 3D viewer or in the "Specification tree", the hand will be selected. If it’s a finger, the selection will be the fingertip. And finally, if it’s a lower body segment, the selection will be the foot.

  3. Select the manikin's left hand or any segment belonging to the hand. The Reach Envelope dialog box appears.

    This allows you to change reach options in term of "Range of Motion"(Current or Specific), "Side" (Both, Right or Left) and "Segment". The panel settings correspond to ones of the existing reach envelope for scenario 1 and to the ones by default (with the corresponding selected segment) for the scenario 2

    By default, the "Range of motion" is set to "Current". This corresponds to the reach envelope generated from the current joints ranges of motion of the selected manikin. You can also create reach envelopes based on "Specific" ranges of motion. There is a choice of 3 different joints ranges of motion settings which are described below. These 3 options are grayed until "Specific" option is selected. When we switch from "Current" to "Specific", the "Range of Motion" and the "Segment" sections will be automatically set to "Ideal" and "Center of Grip" respectively. You can select and generated one, two or even the three "Specific" reach envelopes.
    If you select another segment on one side of the manikin in the 3D viewer or the "Specification tree", the corresponding "Side" will be automatically updated in the panel except if it was previously set to "both". In this case, the selection of the segment won’t have any effect. Finally, the selection of one of the central segments (segments of the trunk and the head) corresponds to "Both" in the panel.
    It’s important to mention here that the 3 "Specific" reach envelopes can’t be generated at the feet. Therefore, a click on any upper and lower body segment (except the fingers) will always correspond to the selection of the "hand".
    The reach envelope is computed only after clicking the "OK" button. The "Cancel" button closes the command and don’t take into account the changes that have been made in the panel.

     

  4. The reach envelope, a surface representing the maximum reach limit, is created around the shoulder joint.




     

    The reach envelope computation will take the IK offset of the selected segment into account. (For more information about offset functionality, see Redefining the Segment Offset for Inverse Kinematics.) This will enable you to create the Reachability of the tip of a tool, for example, if the offset of the hand had previously been relocated to that point on the tool.

    The reach will also be influenced by the arm's angular limitations and preferred angles. For example, it is possible to create a reach envelope representing the comfort zone for a given task.

  5. Change the graphical properties in  the reach envelope's Properties dialog box. Right-click on the reach envelope, and select Properties in the contextual menu.


     

  6. Using the Posture Editor, the IK Mode, or the Standard Pose command, manipulate the manikin's spine. The reach envelope will follow. Select the selection of the segment from the PPR tree.

  7. Delete the reach envelope. To do this, make sure that you are in the Human Builder workbench for that manikin (double click on the manikin's name in the PPR tree). Right-click on the reach envelope and select from the contextual menu as shown below. To return (if needed) to the Human Task Simulation workbench, double-click on the Process name.

 
 

Ideal (short) reach envelope for V5 Human
 

  1. The ideal reach envelope indicates the optimal working area for the selected manikin.  It’s defined as the following; Envelope generated from the motion of the arm (without clavicle) limited to 45 degrees of flexion and abduction (or the center of grip at the shoulder height maximum) as well as 60 degrees of lateral (external) rotation while keeping the forearm in 90 degrees flexed posture.
 

Physiologically maximal (90%) reach envelope for V5 Human
 

  1. The physiologically maximal reach envelope is normally of no practical use, as a human usually doesn’t stretch his joint to full possible extend. The 90% reach envelope corresponds to 90% of the maximum (100%) reach envelope of the arm. It’s defined as the following:

    • Maximum (100%) envelope that has been reduced (shrunk) by an allowance of 10% to take the not-fully stretched joints into account.

    • The lateral rotation is limited to 90 degrees.
 

Extended reach envelope (includes spine bending with body assistance)
 

  1. The extended reach envelope takes the motion of the upper body (spine) into account. Physiologically, it represents the maximal reach range. It’s defined as the following:

    • Maximum (100%) envelope that has been increase by an allowance of 20% to take the motion of the upper body (spine) into account. This 20% will be generated by including a stooping angle of the spine that corresponds to the same horizontal distance than 30% of the arm length (from shoulder to the center of grip). This resulting reach envelope will be then skunk by 10% (of arm length) to take the not-fully stretched arm joints into account.

    • The lateral rotation is limited to 120 degrees.