Diagnóstico

The Jack human figure is built upon the basic modeling elements you have learned in previous sections. However, Jack‘s human models are much more complex than anything you‘ve dealt with up to this point. Jack‘s human model consists of 71 segments, 69 joints (many of which are multi-axis and multiple degree of freedom joint complexes), and 135 degrees of freedom! On top of that, behaviors and constraints are at work in human figures, controlling realistic human responses automatically. Although this chapter is only an introduction to Jack‘s human figure, it is probably the most important in this course.

Jack and Jill Figures

Human Figure Types

The latest Jack and Jill figures are constructed of meshes that deform as the figure moves, much like our own skin. There are two variants of the figure; Base male and female figures clothed in form-fitting outfits that are well suited for detailed accommodation studies, and Clothed figures, that feature typical work attire

including shoes, pants, and shirts.

When an accurate fit or clearance study is the objective, it is recommended that the Base figures are used. The anatomical landmarks used to scale the figure sit on the surface of the Base

figure, so it accurately reflects the desired anthropometric

dimensions. The clothing on the clothed figures has been modeled to reflect a representative offset from the base figures skin surface.

The figures can be scaled to represent the breadth of populations included in the scaling options, and can also be modified to reflect different body shapes.

The clothed figures have been set as the default figures and can be accessed by clicking on the Create default male/female icons along the toolbar:

The base figures can be found in the Human Library: Human->

Create -> Human from Library

v6.0 Figures

With the Jack v6.0 release, figures with deformable surface mesh construction were introduced. These figures were the first

generation of this technology and remain available to support legacy studies. However, it is not recommended that these figures be used for new studies, as the visual look and anthropometric scaling fidelity of the latest figures surpass these early ones.

Segmented Figures

The segmented figures represent the original Jack figure type.

These humans are built of non-deforming geometry to represent each segment. The segmented figures can be used for Advanced Scaling, where the user has additional control over individual segment dimensions.

For any figure type, if you wish to change the skin, hair or clothing colors on your figures, this can be done by right clicking on the human in the Jack scene, selecting Properties and going to the Materials tab. Chose the material you would like to change from

the list (ie. Pants), and click on Properties to bring up the color palette.

Human Hands Disembodied Hands

(Command: Object -> Create -> Figure from Library) At times it may be expedient to only work with individual disembodied hands as compared to posturing the entire body.

Therefore, disembodied hands have been introduced that can be loaded from the Figure Library.

These hands are have the same anthropometry detail as are found on the new figure, and the new hand shape dialogs can be used to posture them.

Note that the anthropometry of these disembodied hands currently cannot be changed

Human Scaling (Anthropometry)

One of Jack‘s most powerful features is the ability to accurately scale human figures. This allows you to evaluate designs for a variety of people sizes without requiring prototypes and test subjects.

5^th, 50^th, and 95^th Percentile Statures

Anthropometry in Jack is particularly useful because of Jack‘s ability to quickly modify body dimensions ―on the fly‖. That is, you can build an environment, create the human figure and define the environmental constraints (such as ―keep your foot on the brake pedal‖), and then modify the human figure‘s measurements. You don‘t have to re-do your analysis for each different scale! This makes performing studies with wide coverage of population percentiles very straightforward.

The Anthropometric Databases found in Jack are:

a) ANSUR (Army Natick Survey User Requirements) 1988 anthropometric database.

b) NHANES: anthropometric data from the National Health and Nutrition Examination Survey (1990)

c) CDN_LF_97: anthropometric data from the Canadian Land Forces (1997)

d) NA_Auto: anthropometric data representing the North American automotive working population.

e) CHINESE: anthropometric data representing Chinese adults aged 18-60 (males) and 18-55 (females). Based on the following report [GB 10000-88], 1989.

f) Asian Indian Anthropometric Database: Indian Anthropometric Dimensions For Ergonomic Design Practice, Ahmedabad, National Institute of Design - 1997

g) German Anthropometric Database: DIN 33402: German Industry Standard, March 2008

h) Japanese:

a. International Standard: ISO7250-1 (2008). Basic human body measurements for technological design, Part 1:

Body measurement definitions and landmarks.

b. Technical Report: ISO/TR 7250-2 (2010). Basic human body measurements for technological design, Part 2:

Statistical summaries of body measurements from individual ISO populations.

i) Korean

a. International Standard: ISO7250-1 (2008). Basic human body measurements for technological design, Part 1:

Body measurement definitions and landmarks.

b. Technical Report: ISO/TR 7250-2 (2010). Basic human body measurements for technological design, Part 2:

Statistical summaries of body measurements from individual ISO populations.

j) Child Figures: Child Data: Snyder et al., Physical Characteristics of Children. Consumer Product and Safety Commission, 1975 (UM-HSRI-BI-75-5).

Figure Scaling

The latest anthropometric scaling gives you control over not only the stature and weight, but also the shape of the figure. Specifically you will notice a Waist to Hip Ratio (WHR) slider on the scaling dialog. This slider allows you to modify the body weight distribution of your figure.

The scaling dialog can be seen below:

To measure Waist to Hip Ratio, it is generally suggested that you measure waist circumference at the smallest part of the waist, and hip circumference at the largest part of the hips, over the buttocks.

These values are then divided to produce a Waist to Hip Ratio.

However, in cases where individuals have large midsections or bellies, the waist circumference should be measured around the largest part of the belly.

Sample Calculation:

Waist Circumference: 33 inches Hip Circumference: 47 inches Notes about scaling:

 The Waist to Hip Ratio slider is only available for the latest figures. All legacy figures will continue to scale using the previous scaling methods. This is to ensure that workflows which rely on older figures (and scaling) are not disrupted.

 If you are using a machine with low memory, try checking the Conserve memory during anthropometric scaling check box in System Defaults->UI dialog. This will reduce the memory foot print of scaling operations.

 33/47 = 0.70

WHR Slider

Create

(Command: HumanCreate)

Create Male and Female Icons

Basic

(Command: HumanCreateCustom)

This brings up the Build Human dialog, which allows the user to create custom humans. From the default Build Human panel the user can create male or female figures of a specified height and weight as well as child sized figures corresponding to a specified age. You can also select which anthropometric database you would like to use to scale your figure.

Human Scaling Icon

The basic HUMAN SCALING PANEL lets you create manikins based on custom or percentile values for height and weight. Statistical algorithms are used to size the other human dimensions and create the human manikin.

Basic Human Scaling Dialog for segmented (left) and smooth skin (right) figures

Advanced

(Command: HumanCreateCustomAdvanced Scaling)

The Advanced Scaling Panel allows for additional control over the segmented human dimensions by letting the user specify a number of anthropometric measurements for the human.

When using the segmented figures, Jack also allows you to model humans of any dimension, not just ―5^th and 95^th‖ models. The advanced HUMAN SCALING PANEL lets you create manikins using specific anthropometric dimensions.

Jack’s Anthropometric Dimensions

Stature Foot Breadth

Abdominal Depth Foot Breadth

Ankle Height Hip Breadth

Acromion Height Interpupil Distance

Arm Length Shoulder Elbow Length

Biacromial Breadth Sitting Acromial Height Bideltoid Breadth Sitting Eye Height Buttock Knee Length Seated Height Elbow Rest Height Sitting Knee Height Elbow-Fingertip Length Thigh Clearance

Foot Length Thumbtip Reach

Hand Breadth Head Height

Hand Length Head Length

Head Breadth

Advanced Scaling Dialog (For use with segmented figures only)

Beyond creating and scaling manikins, the panel serves the function of measuring manikins. When a human figure is selected all of the measures for that human will be displayed on the panel.

Note: To scale for multiple dimensions with a predefined stature and weight, start with simple scaling and scale for stature and weight first. Then use the advanced scaling dialogue to specify other dimensions.

Human Copy

(Command: Human  Copy or RMB on Figure  Copy)

Often it is desirable to quickly copy postural, anthropometric or task specific parameters from one human figure to another. For

example, you may want to test different sized individuals reaching to the same location. The Human Copy functionality addresses these needs.

The Copy Dialog

The Source and Target fields allow you to select the participating humans in the scene.

If the Copy posture checkbox is selected, a number of associated options will become available. Either the Joint Angle-based or Goal-based approaches can be used.

 Joint Angle based

 With this approach, joint posture values are copied from the Source to the Target human.

 The Target human will be constrained to keep the anchor site at the current location and orientation.

However, if the Copy location checkbox is checked, the Target figure will be moved by the anchor site to the same site on the Source Figure.

 Goal based

 With this approach, specific attention is paid to the location of the hands, feet and gaze. This mode is useful for Source and Target figures that have

different anthropometric dimensions. The functionality copies the Joint Angles from the Source to the Target figures, and then attempts to move the hand and feet

locations to match those of the Source figure. It also attempts to have the Target figure gaze in the same general area as the Source figure.

 Note that this option always assumes that the location of the Source and Target figures is the same.

Copy anthropometric properties

 This option will copy the anthropometric dimensions from the Source to the Target figure

 Note that this option is not available if the Source and Target Figures are of different genders.

Copy Loads and Weights

 If Loads and Weights are defined on the Source human, then this option will become available, and will allow you to copy these definitions to the Target figure.

Caution should be exercised when Copying between different generation human figures. It is generally not recommended to use the Anthropometric Human Copy feature between figure versions.

However, if you do try to copy anthropometry between figure versions, the following copy rules will be applied:

Copy Source Copy Target

Anthropometric dimensions to be copied between figures v70-base/clothed v70-base/clothed all

v6x-default/segmented v70-base/clothed link lengths

v6x-default/segmented

v6x-default/segmented all

v70-base/clothed v6x-default not supported

v70-base/clothed v6x-segmented link lengths

Properties

(Command: HumanProperties)

In Jack, human figures are like other types of figures, except they have pre-defined sites, segments, joints, and constraints. There are also special ways of manipulating them and describing their motion (see Human Control dialog). Properties in this dialogue that are common to all figures will be further discussed in the next chapter.

Figure Properties Dialog

Skeleton

(Command: Human PropertiesDisplay Tab)

Figures with joints have an underlying linkage structure that can be displayed. Specifically, the joint locations and the segment structure between these joints are displayed.

Human Skeletal View

Note: Making the human figure transparent or wireframe will allow you to view the skeleton more clearly.

Human Behaviors

(Command: HumanBehaviors)

This dialog can be used to define specific behaviors for your human figure. For example, balance control can be set using this dialog, along with hand, foot and gaze control. Note, that the majority of commonly used behaviors can also be accessed and set using the Human Control Panel (described below).

Human Behaviors

Human Control

(Command: HumanHuman Control)

The Human Control Panel was completely updated for v8.0. To support rapid and easy figure posturing, various dialogs used to control the figure were consolidated into one common user interface. This includes the old Human Control Panel, human behaviors, adjust joint, all hand posturing dialogs, posture libraries, force-based posture prediction as well as the loads and weights dialog.

The Human Control Panel can be launched from the main toolbar, by clicking on . It is also available if you right-click on the human in your scene and choose Control from the context menu.

Human Control Panel

In the Human Control Panel, you will find 2 new posturing features:

Auto-Grasp

This feature offers the easiest way to automatically generate a realistic reach and grasp posture for the human! From the Human Control Panel, click on Jill‘s left or right hand and select Grasp Segment or Grasp Figure. From there, click on an object in the scene where you want your human to grasp. You will see the human automatically reach to the object and wrap his/her hands around the point you specified. Collision detection is used to define the grasp posture. You can also click on ―Adjust Grasp‖ to fine tune the resulting posture.

Braced Posturing

Braced posturing provides for rapid figure posturing in common braced task conditions, along with the ability to predict the associated forces.

Recent research reveals that in addition to posture changes, force exertion

direction is changed when bracing conditions are a factor, and can include substantial off-axis components that impact biomechanical loading. The braced posture prediction is based on these research findings and

computes feet location, body posture and forces.

From the Human Control Panel, load and position one or both of the hand and thigh surfaces, then chose a point in the scene for the figure to

reach/grasp with the free hand(s). The bracing surfaces will be considered during posture prediction. Furthermore, Jack will look to see what hand loads (if any) are on the figure and will apply the appropriate bracing forces, as well as update the task hand force according to the research observations. Braced posturing allows you to predict more realistic postures in scenarios where bracing is possible. In addition, braced posturing impacts your ergonomic analyses, providing a more realistic representation of the forces acting on the human.

Tabs on the Human Control Panel

Each tab on the control panel contains a collection of useful options for posturing and controlling the human figure. In addition to these, you can click on the image of Jill, to access a menu of posturing options for each body part. For example, you can lock/release body parts from this menu as well as access the manipulate and grasp commands for the hands.

Reach & Grasp

Prediction method – Allows you to specify if you‘re posturing the figure for a standing or a seated application.

Lock – allows you to choose which body parts to lock. When locked, this body area will not change as other postural adjustments are made.

A shortcut to lock each body area is available on the Jill image, by holding down the Crtl. key and clicking on a body part.

When Allow Yaw is clicked for the Hand Lock option, this will hold the location of the hand, while allowing ulnar/radial deviation.

Bracing – using the hand and/ or thigh brace glyphs, you can

specify if there are surfaces in your scene that Jack/Jill can lean on.

These will be considered when predicting the overall figure posture AND will update both the task hand forces as well as apply bracing forces. The functionality is based on research conducted at the University of Michigan (www.humosim.org).

When you click on Add Hand Brace / Add Thigh Brace, a glyph will load into the scene. Move the glyph to a location where the human can rest their hand/thighs. For example, if working at a table, the human may be able to rest their thighs against the edge of the table, and their hand along the surface of the table. Once the glyphs are positioned, you can manually manipulate the exertion hand(s) or choose to grasp an object, and the posture prediction will use these bracing surfaces to predict a realistic posture.

If Allow force updates from bracing is checked, braced and task hand forces will be updated and applied to the figure. If unchecked, there will be no change to any loads & weights on the human.

If Display initial hand force(s) is checked, a magenta colored force arrow will appear in the scene to visualize the magnitude and direction that was originally entered prior to a bracing scenario solve.

Foot Placement Zone – when loaded, a red zone (plane) will appear in your scene. The zone will be used as a barrier for

Jack/Jill‘s feet during posture prediction. You can scale the zone to represent boundaries for where your human can place their feet.

Vision Targets – This allows you to select where you want your human to look when postured. You can choose a site on an object (Follow Site) and as that object is moved, the human‘s gaze will follow.

Grasp – From the Jill image, you can right click on a hand to access the Grasp Figure and Grasp Segment commands. These allow you to pick anywhere in your scene and the human will automatically reach to this location and grasp the figure/segment (using collision detection).

 If Precision Grasp is checked, the hand will close around the selected object using this grasp type.

 Adjust allows you to make real time adjustments to the reach and grasp posture.

Loads & Weights

This dialog includes the same functionality as past releases but is now easier to access from the Human Control Panel.

Force Distribution Strategy – allows you to correctly set the

standing posture/strategy of your figure, so that loads are properly estimated and transferred to the Human Performance Tools (TAT) Add Weight/Add Load can be used to assign a force to the human.

You will notice a shortcut for adding a load to the palmcenter sites.

If you click on Add Load or Add Weight, in the editor dialog, a drop down list is available, including the commonly used palmcenter sites.

Show Forces can be used to turn on the display of joint forces.

Click on Add Joint, and select a joint on the human. This will display the forces in the scene and add the joint name to your list.

Adjust Joint

From this tab you can manually adjust individual joint angles on the human. Access to the various body regions can be found in the Body Part drop down list or by clicking on a body part on the image of Jill.

Note: Access to the adjust joint feature will grey out for a body region if other behaviors are set that prohibit a change in joint angle. For example, if the hands are locked, you cannot adjust the

Note: Access to the adjust joint feature will grey out for a body region if other behaviors are set that prohibit a change in joint angle. For example, if the hands are locked, you cannot adjust the

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