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Modeling

Modeling

This chapter discusses general modeling principles including model manipulation, display and access.

Sections

Starting LifeMOD™
LifeMOD Control Panel

Main Modeling Panel
LifeMOD Display Toolbox
Body Move Toolbox
Automated Tutorial Control Panel

LifeMOD™ Command Structure
LifeMOD™ Model Building and Simulation Process

Starting LifeMOD™

After the product installation process, the icon pictured in Figure 1 will appear on the desktop. This icon starts LifeMOD.

Figure 1: Select the LifeMOD desktop icon to start LifeMOD.

When LifeMOD first appears on the screen the program will open the modeling window and a splash screen as depicted in Figure 2. The splash screen is a portal to explore modeling and training functions embedded in the program. It also allows the user to begin creating a new model or to load a previously created model. The user may skip this splash screen by unchecking the box "Show this dialog at startup." The splash screen may be recalled at any time by selecting the LifeMOD button in the lower left corner of the modeling window.

Figure 2: Selecting "New Model" or "Close" brings up the baseline LifeMOD modeling environment

LifeMOD Control Panels

LifeMOD provides a very intuitive graphical user interface. Very detailed human models are created via control panels. These control panels enable the user complete functionality to generate, display, analyze, animate and plot data.

Access to the control panels may be achieved by selecting "New Model", "Open Existing Model" or "Close" is selected on the splash screen the three main LifeMOD panels will be displayed. Figure 3 displays the main modeling panel, the display toolbox and the automated tutorial control panel.

Figure 3: The three main LifeMOD panels.

Main Modeling Panel

Figure 4: LifeMOD main modeling panel displaying the commands (main-menu) and actions (sub-menu) and toolbox access.

Figure 4 displays the LifeMOD main modeling panel. From it, the base human model can be designed with segments, joints, soft tissues, contact points, motion agents, etc. Under each selection is a sub-menu which contains the actions for each main command. The toolboxes on the far right include the LifeMOD Display Toolbox, the Table Editor, the Automated Tutorial Panel, and access to this manual and to the online user's forums. This panel also contains a context sensitive help button which accesses the on-line manual section current for the selection in the main-menu and the sub-menu.

LifeMOD Display Toolbox

Figure 5: LifeMOD Display Toolbox

Figure 5 displays the LifeMOD Display Toolbox used to manipulate the appearance of the model. The top line of the LifeMOD Display Toolbox specifies the active body (when multiple bodies are present in the model), and manipulates the basic view functions:

f - fit in view
z - zoom view
w - zoom in window
r - rotate
t - translate
c - center view
S - toggle between solid and wireframe representation
v - turn icons on/off

The middle section of the panel includes an entity manipulation section. This section offers controls for internal/external representation display functions. Models may be represented as a combination of external and internal representation. When an internal representation is used other than "none" the external representation will change to semi-transparent. The user may affect the level of external and internal transparencies using the sliders at the bottom of the panel. The entities that can be manipulated are listed below.

Body

Body CM tracker
Vision Cones
Foot detailed graphics

Tissues

Muscles
Ligaments/Tendons
Attachments
Tissue Icons

Joints

Graphics
Axis-Major
Axis-Minor

Motion Agents

Segment CG Set
Davis Set
Plugin Set
Golf Set
Motion Matrix Set
Tracker Set

Misc. Items

Markers
Constraints
Forces

The bottom of the panel offers control of the ADAMS icons and components. These include markers, constraints, forces, parts, and geometry.

LifeMOD Move Toolbox

Figure 6 displays the LifeMOD Move Toolbox, which can be accessed from the Display Panel when any of the options under the Move Tools pull-down menu are selected. This toolbox is used to move the entire body. Rotations are performed around the screen center which can be set with the button in the center of the rotation panel.

Figure 6: LifeMOD Move Toolbox used to move the entire body.

Automated Tutorial Control Panel

Figure 7: The automated tutorial control panel.

Figure 7 displays the Automated tutorial control panel. This panel automatically steps through any of the available tutorials in LifeMOD. The tutorials themselves are designed self-training tools. The best way to use the tutorials is by following the manual (select the question mark for the specific tutorial document) while moving through the tutorial. The panel displays the current chapter and step of the tutorial and controls to single step through or fast forward to a specific step.

LifeMOD Command Structure

The command structure available in the LifeMOD panel is grouped into Top-level and Sub-level commands.

Top-Level	Sub-Level	Description
Segments	Create Base Segment Set Create Individual Segment Edit Segment Update Segment Contents Import Delete	Create segments for base model Create a single segment from existing geometry or bones Edit mass properties and dimensions of a segment Update contents of a segment Import geometry file for non-standard segment Delete single body or bodies
Joints	Create Base Joint Set Create Individual Joint Training Edit Properties Delete	Create the base body model joints Create a custom joint between any two segments Switch between recording and active joints Edit joint properties and parameters Delete single or set of joints
Soft Tissues	Create Base Tissue Set Create Individual Tissue Create Tissue Wrapping Training Edit Properties Delete	Create base muscle-tendon sets on the body model Create a custom muscle or tendon Create wrapping around solid objects Switch between recording and closed-loop active muscles Edit properties of the tissue, change/reassign attachments Delete tissue(s)
Posture	Configure Base Model Configure Single Joint	Pose model with stored library posture or adjust joints Adjust individual joints
Contacts	Create Base Contact Set Create Individual Contact Create Grip Forces Read GRX Data Create Ground Reaction Forces Delete	Create multiple segment/environment contacts Create the contact force between the body segments and the environment or between segments (i.e., force-based contact joints) Create grasping-simulation contact forces without constructing actual grasping structures in the hands Read in GRF data from an SLF file Generate GRF contacts from GRF data Delete contact elements
Motion	Import Motion Capture Data Create Base Motion Agent Set Augment Motion Agent Set Create Individual Motion Agent Create Tracker Agent Edit Base Set Delete	Import digitized motion data Create motion agent sets on the segments of the model to drive the motion of the model Create motion agents in large groups at a time Create a single motion agent on a segment of the model Create a stabilizing tracker agent Exchange motion data for existing agents Delete motion agents
_Analyze	Dynamics Statics Body Velocity Initial Conditions	Run dynamics analysis Run statics analysis Add body segment initial conditions before the simulation
_Results	Animation Data Display Data Calculation	Manage animations Manage model data plotting Calculates Head and Neck Injury Criteria (HIC/NIC)
__Plugins	NeckSIM LumbarSIM MotionMatrix	New LifeMOD module for creating a detailed cervical spine New LifeMOD module for creating a detailed lumbar spine New LifeMOD module for using skin-based sensors to drive the model
__Parameters	Geometry Joints Tissues Contacts Motion Agents	Edit the size of the foot ellipsoids Edit various joint factors Edit various tissue properties Edit contact properties Edit motion agent weighting schemes
__Xchange	Import SLF Model File Import Mechanical Envirionment Import Test Data Export SLF File Export ADAMS/Solver File	Import file containing data on units, anthopometrics, joints, posture, MOCAP Import external modeling objects (cars, tennis rackets, chairs, etc) Reads in data in the form of spline curves Export an SLF file to be accessed by other programs Writes an ADAMS data set file for the whole model

LifeMOD™ Model Building and Simulation Process

The basic steps in generating are listed below and illustrated in the tutorial examples detailed in this manual.

Figure 8: Flowchart of the Modeling Paradigm