Step 5.3: The Motion-Dimension FB

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Step 5.3: The Motion-Dimension FB

Motion-Dimension FB

About the Motion-Dimension FB

A Motion-Dimension FB identifies a Part whose motion we want to control. Often, we say it is a Motion-Part.

We control the position, velocity, and acceleration of a Motion-Part with two parameters:

Base-Value (a parameter in the Motion-Dimension dialog )

This is the position of the Motion-Part when there is not a wire at the input-connector to the Motion-Dimension FB, or when the motion-value at the input-connector is zero.

Motion-values (motion-values at the input to the Motion-Dimension FB)

The motion-values control the position, velocity, and acceleration of the Motion-Part relative to a different Part.

Motion-Dimension = Base-Value + Motion-Value

There are two types of Motion-Part:

•Rocker : Part + Pin-Joint + Motion-Dimension FB

•Slider : Part + Slide-Joint + Motion-Dimension FB
tog_minusAdd Motion-Dimension FB

 

Command-Manager:  Add Motion-Dimension FB

Command-Manager:
Add Motion-Dimension FB

GST-Icon-FB-MotionDimension

1.Expand the Kinematic FB toolbar - it is to the right of the graphics-area.

2.Click Add Motion-Dimension FB

OR

1.Click Main menu > Function-Blocks

2.Click Motion-Dimension

The Command-Manager has three selection-boxes. You must select these element-types:

Red-14-1b A Slide-Joint ( or Pin-Joint )

Red-14-2 A solved Point ( or Line )

Red-14-3 An unsolved Point ( or Line )

if Red-14-1b is a Slide-Joint, then Red-14-2Red-14-3 are Points

if Red-14-1b is a Pin-Joint, then Red-14-2Red-14-3 are Lines

 

Red-14-2 is a Line or Point in a Part that is kinematically-defined

Red-14-3 is a Line or a Point in Part that is free
tog_minusA Rocker

Prepare the model with these elements.

ROCKER

The kinematic state of each element below (Red-14-1bRed-14-2Red-14-3) is before you add a Motion-Dimension FB.

Element #

Element Type

Rules

1r

Pin-Joint

•The Pin-Joint Is between two(2) Points

•Each Point is the start-Point or end-Point of a Line (or CAD-Line)

•Each Point is a child to a different Part

•One Part IS kinematically-defined, the other Part is NOT kinematically-defined

2r

Line

•Is a Line that radiates from the Pin-Joint (see Element #1)

•AND this Line is in the Part that IS kinematically-defined

3r

Line

•Is a Line that radiates from the Pin-Joint (see Element #1)

•AND this Line is in the Part that is NOT kinematically-defined
Preparation for a Rocker

Preparation for a Rocker

Preparation (typical):

•Pin-JointRed-14-3

•The Points at Pin-JointRed-14-3 are at the ends of LinesRed-14-4Red-14-5.

•LinesRed-14-4Red-14-5 are in two different PartsRed-14-1bRed-14-2 , and they that radiate from the Pin-Joint

•PartRed-14-1b is a Part that is kinematically-defined (Green Part-Outline).

•PartRed-14-2 is a Part that is free (Blue Part-Outline)

STEP 1: Start the Command

Add Motion-Dimension FB

1.Click Kinematics FB toolbar > Motion-Dimension FB

or

1.MD16: Click Add menu > Add Motion-Dimension FB

1.MD17: Click Function-Blocks menu > Motion-Dimension

The Command-Manager indicates that there are three elements to select:

STEP 2: Select the three elements in the graphics-area

Element #1: PIN-JOINT

1.Click a Pin-JointRed-14-3Red-14-5

The Pin-Joint must be a joint between two(2) Parts, and:

•One Part is kinematically-defined Red-14-1b

•The other Part is free Red-14-2

Elements #2 and Element #3: Lines Red-14-4Red-14-5

Each of the Points at the Pin-Joint (Element #1) must be a child to Lines (Element #2 and #3).

2.Click LineRed-14-4 in the Part that is kinematically-definedRed-14-1b

3.Click LineRed-14-5 in the Part that is freeRed-14-2

STEP 3: Complete the Command

1.Click OK-tiny-11-15 in the Command-Manager to complete Add Motion-Dimension FB (Rocker).

 

GST-5-3-AddMotionDimRock-1

GST-5-3-AddMotionDimRock-2
Rocker: kinematically-defined Part

Rocker: kinematically-defined Part

Result : a Rocker

The free Part is now kinematically-defined.

A Motion-Dimension FBRed-14-1b and Motion-DimensionRed-14-2 control the angle between the two Lines

GST-Icon-FB-MotionDimension-Rocker--inGA

The Motion-Dimension FBRed-14-2 icon in the graphics-area for a Rocker.

 

Note:

There are two different mouse-actions to move the FBRed-14-1b or to move the DimensionRed-14-2

To move the FB Red-14-1b :

DRAG the Function-Block  

To move the Dimension Red-14-2 :

CTRL+DRAG the Function-Block

GST-5-3-KT-Rocker

Kinematics-Tree for a Rocker

When we add a Motion-Dimension FB to a Pin-Joint, the Motion-Part is a Rocker in the Kinematics-Tree.

The kinematic elements are:

Part + Pin-Joint + Motion-Dimension = Rocker

 
tog_minusA Slider

Prepare the model with these elements.

SLIDER

The kinematic state of each element below (Red-14-1bRed-14-2Red-14-3) is before you add the Motion-Dimension FB.

Element #

Element type

Rules

#1

Slide-Joint

•Is between two(2) Lines*

•Each Line* is a child to a different Part

•One Part IS kinematically-defined, the other Part is NOT kinematically-defined

* Line and/or Cad-Line

#2

Point

•the start-Point or the end-Point of one of the Lines in the Slide-Joint (see Element #1),

•AND the Point (and Line) is a child to the Part that is kinematically-defined

#3

Point

•the start-Point or the end-Point of one of the Lines in the Slide-Joint (Element #1)

•AND the Point (and Line) is a child to the Part that is free

* Line or CAD-Line
A Sliding-Part

A Sliding-Part

Preparation example:

1.Two PartsRed-14-1bRed-14-2  

One Part is kinematically-defined . It is the Base-PartRed-14-1b

The other a is free Part Red-14-2

2.A Slide-JointRed-14-3 joins the two Parts

Note : PointsRed-14-4Red-14-5 are start-Points of the Lines that you select to add the Slide-JointRed-14-3

GST-5-3-CM-AddMotionDimension-Slider1

STEP 1: Start the Command

Add Motion-Dimension FB

1.Click Kinematics FB toolbar > Motion-Dimension FB

or

1.MD16: Click Add menu > Add Motion-Dimension FB

1.MD17: Click Function-Blocks menu > Motion-Dimension

The Command-Manager indicates that there are three elements to select.

STEP 2: Select three elements in the graphics-area

Element #1: Slide-JOINT

1.Click a Slide-JointRed-14-3

The Slide-Joint must be a joint between two(2) Parts and:

•One Part is kinematically-defined Red-14-1b

•The other Part is free Red-14-2

Elements #2 and Element #3: POINTS Red-14-4Red-14-5

Each Point must be a child to a Line that is also a child to the Slide-Joint. (Element #1)

2.Click the PointRed-14-4 in the Part that is kinematically-definedRed-14-1b

3.Click the PointRed-14-5 in the Part that is freeRed-14-2

STEP 3: Complete the Command

1.Click OK-tiny-11-15 in the Command-Manager to complete Add Motion-Dimension FB (Slider).

Result : a Slider

The free Part is now kinematically-defined.

A Motion-Dimension FBRed-14-1b and Motion-DimensionRed-14-2 control the distance between the two Points.

GST-Icon-FB-MotionDimension-Slider-inGA

The Motion-Dimension FB iconRed-14-1b in the graphics-area for a SLIDER.

Note: There are two different mouse-actions to move the FB Red-14-1b or to move the DimensionRed-14-2.

To move the FB Red-14-1b :

DRAG the Function-Block :  

To move the DimensionRed-14-2 :

CTRL+DRAG the Function-Block

GST-5-3-CM-AddMotionDimension-Slider3
A Slider

A Slider

GST-5-3-KT-Slider

Kinematics-Tree

When we add a Motion-Dimension FB to a Slide-Joint, we identify it as a Slider in the Kinematics-Tree.

The kinematic elements are:

Part + Slide-Joint + Motion-Dimension = Slider

 
tog_minusMotion Dimension dialog box

GST-5-3-MotionDimensionFB

After you add the Motion-Dimension FB, you can open the Motion-Dimension dialog.

To edit the Motion-Dimension FB:

1.Double-click the Motion-Dimension FB in the graphics-area

The Motion-Dimension dialog is open.

2.Edit the:

oBase-Value

or

oBase-Value + Motion Value

The Base-Value is the position of the Motion-Part (Rocker or Slider) when the a wire is not connected to the input-connector of the Motion-Dimension FB, or the motion-value at the input-connector is zero.

 

Directions separator:

•Edit the positive/negative directions of the Base-Value

•Edit the positive/negative directions of the Motion-Values.
tog_minusUse a Graph FB to display the motion-values at the output-connector of a Motion-Dimension FB

1.Add two Linear-Motion FBsRed-14-1Red-14-4 to the graphics-area.

2.Add a Graph FBRed-14-3 to the graphics-area

3.Connect a wire from the Linear-Motion FB(1)Red-14-4 to the X-axis input of the Graph FB

4.Edit the Base-Part and add a Line

5.Add a Part.

6.Add a Pin-Joint to join the start-Point of the Part to the start-Point of the Line in the Base-Part.

7.Add a Motion-Dimension FBRed-14-2 to identify the Part as a Rocker.

8.Connect the other Linear-Motion FB(2)Red-14-1 to the Motion-Dimension FB, and from the Motion-Dimension FB to the Y1 input of the Graph FB.

9.Double-click Linear-Motion FB(2) ; edit the Start-Value to 30Red-14-5

10.Double-click Motion-Dimension FB ; edit the Base-Value to 110Red-14-6

11.Double-click Graph FB to show the plot.

GST-5-305

In the image, the Master-Machine-Angle (MMA) is 120º.

Thus, the output from the Linear-Motion FBRed-14-1 and input to the Motion-Dimension FB is 120º + 30º = 150º.

The Base-ValueRed-14-6 of the Motion-Dimension is 110º.Red-14-6

The angle of the Rocker is Base-Value + Motion-Value = 110º + 150º = 260º.

The output from the Motion-Dimension FB is the input to the Graph FB.

When you open the Graph FB, the vertical cursorRed-14-7 is at the MMA.

If you set the cursor Red-14-7 to 120º, the Y-axis value is 260º.Red-14-8

The graph is a plot of the output of the Motion-Dimension FB (Y-axis) against the MMA (X-axis)