SolidWorks Motion and Finite Element Analysis (FEA) Simulation
Creating Motion in SolidWorks-Motion Drivers
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Transcript of Creating Motion in SolidWorks-Motion Drivers
Jim Boland P.E., CSWP
Creating Animation with SolidWorks
Motion Drivers
What Is Going To Be Covered?
• Basic principles of animations.
• Choosing the right type of Motion Study.
Animation, Basic Motion, or Motion Analysis
• Motion Drivers Physics
−Gravity
−Contact
−Springs
−Friction
−Damping
Motors
−Constant Speed
−Distance
−Oscillating
−Interpolated (2010) / Data Points (2011)
−Segment
−Expression
Keypoint
Animation Wizard
Mates
−Angle
−Distance
−Path
You’ve go to be very careful if you don’t know where you are going because you might not get there. -Yogi Berra
Presentation Goals
• Explore the different types of motion drivers available.
• Explore the different methods to create animations.
• Reduce frustration when creating animations
The tools and principles used are not rocket science.
The UI is similar to other video programs.
• Tools and Methodology
You can learn what the tools do from the Help menu, but not methodology.
Key is to know how to use the tools and what to do if it doesn’t work.
Methodology and multiple approaches.
Right Way vs. Wrong Way.
We made too many wrong mistakes. -Yogi Berra
Presentation Goals
Questions from the SolidWorks Forum
•Why aren’t in-context parts solved in Basic Motion?
•Why do parts overlap when using Contact?
•Why doesn’t contact stop motion driven by a motor?
•Why doesn’t my animation solve when I add a second or third motor?
•How do I animate a robot?
Learning Resources
• Tutorials
• SolidWorks User Forum
• Training classes
• Step-by-Step books
Audience Makeup
• SolidWorks Version
2011
2010
2009 or earlier
• Animation Experience
Beginner
Intermediate
Advanced
Important
We are creating
Animations
NOT
Analysis
What is an Animation?
• We are creating movies
Series of still images played back in rapid sequence
Adjustable frame rates
We are in control, not the viewer
No CG animations
• What frame rate should you use?
Frame Rate Standards:Movies – 24 fps
TV – 30 fps
• What happens if the frame rate is too slow or too fast?
Frame Rate too slow – jerky motion
Frame Rate too fast – jerky motion
(OK, 29.97 for the purists)
3 x 3
The 3 things you need to know
About
The 3 things you need to know
The 3 X 3 Choices
• 3 - Motion Study Types
Animations
Basic Motion
Motion Analysis
• 3 - Motion Types
Kinematic
Dynamic
Free
• 3 - Things You Animate
Components
Properties
Viewpoint
Free Motion and Kinematic Motion
Dynamic Motion
The Basic Rules of Motion Studies
• Mates are solved.
• Parts are rigid.
• Frame rates are adjustable in two places.
• Frame rate means something different in Basic Motion / SolidWorks Motion as compared to Animation studies.
Animations Motion Studies
Animation Motion Studies
How is the motion calculated?
Frame rate drives the solution
Components move directly from one position to the next
At time zero, take a picture
Move the drivers ahead one frame
Rebuild−Solve the mates
−Solve in-context features
Take another picture
Repeat
Basic Motion / SolidWorks Motion
• Used when:
• Physics need to be solved
Physical Properties
• Mass
• Gravity
• Forces
• Contact
• Momentum
• Friction
• Damping
Drivers:
• Gravity
• Motors
• Springs
• Contact
• Forces
• Dampers
• Friction
Basic Motion / SolidWorks Motion Studies
• How are Basic Motion/SolidWorks Motion studies solved?
You have to solve the physics of the model.
Numerical methods using small time steps.
Solvers.
Solver optimization.
• What does the frame rate do?
As far as the solution is concerned – NOTHING
Frame rate determines the intervals when the data is captured for display.
• Important: In-context features are not solved in either the Basic Motion or SolidWorks Motion study types.
Types of Motion Drivers
• Key Points
• Mates
• Motors
• Gravity
• Springs
• Contact
• Force
• Damper
Features
X = Available Function
L = Limit Functionality
Keypoint Animations
• Basic Workflow
Position the Timebar
Position the driving components
Position the viewpoint
Adjust Properties
Record the Keypoint (automatic or manual)
Repeat
Remove the Nut and Bolt
01
Exploded View
• Exploded Views provide a simple method to create a lot of motion.
Create exploded views in SolidWorks
Import into Motion Study using the Animation Wizard
02
Interpolation Methods
Snap
Ease In
Linear
Ease Out
Ease In/Ease Out
02
Mates
• Global vs. Local Mates
• Driving Mates
• Distance Mate
• Angle Mate
• Path Mate
• Driven Mates
• Use Standard Mates with Basic Motion
• Avoid Width mate
• Screw mate for rotation with translation
• Mate Organization
• Mate Order
• Mate Names
• Use Folders
• Sub-assemblies
Mates – The Good, The Bad and the Ugly
• The Good
• Easy to use
• The Bad
• Some mates don’t work (or work well) in animations (Width mate)
• Some mates don’t solve all options (Path mate)
• Some mates better for SolidWorks Motion, others better for Basic Motion
• The Ugly
• Mates sometimes flip unexpectedly and inconsistently
• Problems with sub-assemblies
Mates
• Distance Mate
• Avoid changes in direction and alignment
• Can be done but sometimes solve incorrectly
• Replace global mate with a local mate specifically for the animation
• Angle Mate
• The 100/360 Rule
• Path Mate
• Free
• Distance
• Percent
01
Path Mates
03
The 100/360 Rule
• When using degrees: 0 and 360 are 360 degrees apart
0 and 360 are not the same.
You cannot use angles >360 degrees
• When using percent: 0 and 100% are 100 percent apart
0% and 100% are not the same
You cannot input values greater than 100%
• Difference between keypoints and mates
at these values
04
When an Animation does not solve
If at first you don’t succeed -
Try, try againGive up, why be hard headedTry a different method
When you come to a fork in the road, take it……
- Yogi Berra
Motors
• Motor Types
• Rotary
• Linear
• Motion
• On/Off
• Constant Speed
• Distance
• Interpolated/Data Point
• Segment
• Expression
• Oscillating
• Servo Motor
Motor Facts
• Important: motor force is infinite
• Motors can be used as mates. (Reduces redundancies)
• Motors can have problems across mates
• Must define three things:
What is the motor acting on
What direction is the motor acting
What is the motor moving relative to
• When motors don’t work, the most likely cause is a conflict between motors
Robot
• There are seven motion drivers required
• 6 rotary
• 1 linear
Motors
• Distance Motor
• Angle or Distance
• How far
• Start
• Duration
• Graph
(no instantaneous change)
Motors
• Constant Speed Motors
• “ON” time
• Speed
• Smooth transitions
Motors
05
Interpolated Motor (2010)
Linear
Akima
Cubic
Function Builder
• Used to define the motion by:
Segments
Data Points
Expressions
• Different data interpolation methods
• Provides plots:
Distance
Velocity
Acceleration
Jerk
Data Points (2011)
• Input
• Type in the box
• Text file
• Values
Displacement
Velocity
Acceleration
• Interpolation
Linear
Akima
Cubic
Segments (2011)
• Another way to define curve
• Piecewise continuous
• More interpolation types
• Interpolation defined by segment
Expression
• Predefined functions
Mathematical Functions
Variables and Constants
Motion Study results
• Functions can be saved and reused (*.sldfnc)
Motors
Expression Motion
•Only variable in Animations & Basic Motion is Time
•Can use most VB functions
•There are three forms of time (2010)
• Linear - TIME
• Radians - TIMER
• Degrees - TIMED
•SolidWorks Motion can use other variables
Allowable Functions
ABS ACOS AINT ASIN
ATAN ATAN2 COS COSH
DIM EXP LOG LOG10
MAX MIN MOD SIGN
SIN SINH SQRT STEP
TAN TANH DTOR PI
RTOD TIME IF
Important: In 2010, distance units are Meters, in 2011 distance units are the document units.
05a
The Problem
13
5m
m
20
0m
m
85m
m
35
mm
50m
m
24
mm
The Problem
Desired Video
Camera Lens Equation
• View Angle α = 2 * atan (d/2f)
• For lenses longer than 50mm α = d/f
07
Gravity
• Used in Basic Motion and SolidWorks Motion
• Magnitude error in Basic Motion 2009 and earlier
• Gravity does NOT have to be realistic in an animation, only in analysis
Contact
• Basic Motion and SolidWorks Motion only
• Contact Groups• Friction• Contact Resolution• Contact Accuracy• Differences between Basic
Motion and SolidWorks Motion
Spring
• Used in Basic Motion and SolidWorks Motion
• Spring only shows during calculation
• Spring Constant
• F=kxe
• Linear only in Basic Motion
• Powers of up to ± 4 in SolidWorks Motion
• Error in Basic Motion by one order of magnitude
• Spring damping
• Global in Basic Motion
• Adjustable in SolidWorks Motion
Problem
• What type of Motion Study?
• Animation
• Basic Motion
• Motion Analysis
• Basic Motion
• Spring
• Gravity
Other Solutions
• Oscillating Motor
• Easy to set up
• No damping
• Expression Motor
• Can make the motion anything you like
• Distance = Decay function x Amplitude x Sin (Time)
Combined Curves
Contact and Spring
• Spring for animation vs. spring for visual animation
• Contact properties• Contact Resolution• Contact Accuracy
• Best Method ?????• Animation• Basic Motion • SolidWorks Motion
Friction
• Used in Basic Motion and SolidWorks Motion
• In Basic Motion, friction is determined by material.
• In SolidWorks Motion, friction can be applied at:
• Joints
• Contact
Damping
• Only available in SolidWorks Motion
• Different from spring damping
Force
• Only available in SolidWorks Motion
• Options are similar to those used for motors
• Constant
• Interpolated
• Expression
The Laws of Animations
• Remember: You are creating an animation, not doing an analysis.
• The Law of Simplicity
• The best solution is most often the simplest solution
• KISS principle
• The Law of Diminishing Returns
At some point, more and more effort is required for smaller and smaller improvements
Questions
The End