Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ1
Simulation Software: Simulation Software:
Performances and Performances and
ExamplesExamples
Dr. Mario Acevedo
Multibody Systems and Mechatronics Laboratory
Engineering School,
UNIVERSIDAD PANAMERICANA
(Mexico City)
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ2
AgendaAgenda
Objective and scope
Simulation software: overview
Kinematics simulation
Dynamics simulation
Simulation using web technology
Final remarks
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ3
Objective and ScopeObjective and Scope
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ4
About this PresentationAbout this Presentation
Objectives:
Introduce the topic of simulation software for robotic
multibody systems
Explain the problems that can be solved
Show an idea of the implementation
Motivate collaboration in the study of problems, prototypes:
oThe development of a common language to describe systems
(XML)
oUse of WEB technologies for publications and collaboration
Scope
All theory and examples will be treated in 2D.
3D systems are treated in similar way
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ5
Simulation Software: Simulation Software:
OverviewOverview
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ6
Simulation of MBSSimulation of MBS
Many computer codes have been
developed but they differ in:
Model description
Choice of basic principles of mechanics
Topological structure
Numeric vs. Symbolic
Formulations
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ7
MBS Simulation OptionsMBS Simulation Options
Modeling
Cartesian coordinates
Relative coordinates
Fully Cartesian coordinates
Graph theory
Spatial algebra
Principles of Mechanics
Virtual Power
Newton-Euler
Hamilton’s Principle
Lagrange’s Equations
Gibbs-Apell Equations
Formulations
Spatial Algebra
Velocity Transformations
Recursive Methods
Baumgarte Stabilization
Penalty Methods
Augmented Lagrangian
Numerical Integration
ODE Methods
Implicit Integrators
Explicit Integrators
Single step vs Multistep
DAE Methods
Backward Difference
Implicit Runge-Kutta
Intelligent Simulator
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ8
Software for Multibody Systems Software for Multibody Systems
Simulation 1Simulation 1
ADAMS by Mechanical Dynamics Inc., United States
alaska , by Technical University of Chemnitz, Germany
AUTOLEV , by OnLine Dynamics Inc., United States
AutoSim by Mechanical Simulation Corp., United States
COMPAMM by CEIT, Spain
DADS by CADSI, United States
Dynawiz by Concurrent Dynamics International
DynaFlex by University of Waterloo, Canada
Hyperview and Motionview by Altair Engineering, United States
MECANO by Samtech, Belgium
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ9
Software for Multibody Systems Software for Multibody Systems
Simulation 1Simulation 1
MBDyn by Politecnico di Milano, Italy
MBSoft by Universite Catholique de Louvain, Belgium
NEWEUL by University of Stuttgart, Germany
RecurDyn by Function Bay Inc., Korea
Robotran by Universite Catholique de Louvain, Belgium
SAM by Artas Engineering Software, The Netherlands
SD/FAST by PTC, United States
SIMPACK by INTEC GmbH, Germany
Universal Mechanism by Bryansk State Technical University,
Russia
Working Model by Knowledge Revolution, United States
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ10
Actual State of MBS SimulatorsActual State of MBS Simulators
Model
Description
User Interface
SOLVER
Post-processor
1
Model
Description
User Interface
SOLVER
Post-processor
2
Model
Description
User Interface
SOLVER
Post-processor
n
…
…
…
…
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ11
Desired Goal of MBSDesired Goal of MBS
Model Description ( Neutral Data Format )
User Interface
SOLVER
Signal Analysis
1
User Interface
SOLVER
Animation
2
User Interface
SOLVER
Strength Analysis
n
…
…
Standardized Result Description
Visualization
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ12
Kinematics SimulationKinematics Simulation
Modeling:
Coordinates, Constraints and Joints library
Analysis:
Positions, Velocities and Accelerations
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ13
Coordinates for ModelingCoordinates for Modeling
Relative coordinates
Minimum set of coordinates
Cartesian coordinates
Also known as Reference Point
coordinates
Fully Cartesian coordinates
Also known as Natural Coordinates
Mixed coordinates
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ14
Constraints EquationsConstraints Equations
If the selected set of coordinates is
dependent, a set of constraint equations can
be found
Constraint equations relate the dependent
coordinates and define the movement geometry
NoC = NoDC – NoDOF
NoC: Number of Constraints
NoDC: Number of Dependent Coordinates
NoDOF: Number of Degrees of Freedom
Constraint equations generally are not linear
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ15
Relative CoordinatesRelative Coordinates
Open kinematic chain
Model
Close loop
Constraints
No constraint
equations since it is
an open kinematic
chain
1
2
X
Y
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ16
Relative CoordinatesRelative Coordinates
Close kinematic chain
Model
Constraints
NoDC = 3
NoDOF = 1
NoC = 3 - 1 = 2
Non linear
Transcendental
functions
1
X
Y
2
O D
0sinsinsin
0coscoscos
321321211
321321211
LLL
ODLLL
3
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ17
Cartesian CoordinatesCartesian Coordinates
Open kinematic chain
Model
Constraints
NoDC = 6
NoDOF = 2
NoC = 6 - 2 = 4
Non linear
1
2
X
Y
y
(x
y
(x
y
0sin
2
sin
0cos
2
cos
0sin
2
0cos
2
22
2
11
22
2
11
11
1
11
1
y
L
L
x
L
L
y
L
x
L
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ18
Cartesian CoordinatesCartesian Coordinates
Close kinematic chain
Model
Constraints
NoDC = 9
NoDOF = 1
NoC = 9 - 1 = 8
Non linear
2
O D
1
X
Y
(x
y
(x
y
(x
y
0sinsinsin
0coscoscos
0sin
2
0cos
2
0sin
2
sin
0cos
2
cos
0sin
2
0cos
2
332211
332211
33
3
33
3
22
2
11
22
2
11
11
1
11
1
LLL
LODLL
y
L
x
L
OD
y
L
L
x
L
L
y
L
x
L
3
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ19
Fully Cartesian CoordinatesFully Cartesian Coordinates
Open kinematic chain
Model
Constraints
NoDC = 4
NoDOF = 2
NoC = 4 - 2 = 2
Non linear
1
X
Y
y
(x
y
(x
y
2
(x
y
0
0
2
2
2
12
2
12
2
1
2
1
2
1
Lyyxx
Lyyxx
OO
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ20
Fully Cartesian CoordinatesFully Cartesian Coordinates
Close kinematic chain
Model
Constraints
NoDC = 4
NoDOF = 1
NoC = 4 - 1 = 3
Non linear
2
O D
1
X
Y
(x
y
(x
y
3
0
0
0
2
3
2
2
2
2
2
2
2
12
2
12
2
1
2
1
2
1
Lyyxx
Lyyxx
Lyyxx
DD
OO
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ21
Constraints OriginConstraints Origin
Constraint equations generally are obtained
from:
Close loop equations
Relative coordinates
The rigid body condition of the elements
Fully Cartesian coordinates
Joints definition
Cartesian and Fully Cartesian coordinates
Joints definition can be part of a joints library
Treat the multibody system as a LEGO
Use computational tools in multibody systems
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ22
Kinematics of MBSKinematics of MBS
Set of dependent coordinates: q
Positions analysis.
Set of constraint equations:
Solution using iterative procedures (Newton
Raphson)
Velocity analysis:
Acceleration analysis:
t,qΦ
tt ΦqqΦ
q ,
( 3 )
( 2 )
( 1 )
cqΦΦqqΦ
qq
tt,
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ23
Joints DefinitionJoints Definition
Limited to systems in plane (2D)
Cartesian coordinates
Lower-pairs: revolute and prismatic
Show the general modeling for the joint
Identify the corresponding elements in
and
Higher-pairs: gears, cams, etc.
Require some information on the shape of the connected
bodies
Require to know the shape or curvature of a slot in one of
the bodies
t
t ΦqqΦ
q
,
cqΦΦqqΦ
qq
tt,
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ24
Modeling of the Revolute JointModeling of the Revolute Joint
X
Y
i j
r
ir
j
P
P
i
s
P
j
s
jPy
j
jPx
j
iPy
i
iPx
i
jPy
j
jPx
j
iPy
i
iPx
i
r
ssss
ssss
sincos10sincos10
cossin01cossin01
2,
q
Φ
Py
j
Px
j
jj
jj
j
j
Py
i
Px
i
ii
ii
i
ir
s
s
y
x
s
s
y
x
cossin
sincos
cossin
sincos
2,
Φ
2
2
2
2
2
2
2,
cossin00cossin00
sincos00sincos00
j
j
j
i
i
i
jPy
j
jPx
j
iPy
i
iPx
i
jPy
j
jPx
j
iPy
i
iPx
i
r
y
x
y
x
ssss
ssss
qΦ
q
P
j
jjP
i
ii
r
sArsArΦ
2,
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ25
Modeling of the Prismatic Joint 1Modeling of the Prismatic Joint 1
X
Y
i j
r
i
r
j
P
i
Q
i
P
j
is
d
in
0
0
2,
c
ji
T
it dn
Φ
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ26
Modeling of the Prismatic Joint 2Modeling of the Prismatic Joint 2
c
ssyssyssss
ssxssxssss
ji
iPy
i
iPx
i
ijPy
j
jPx
j
jiQy
i
iQx
i
iPy
i
iPx
i
iPy
i
iPx
i
ijPy
j
jPx
j
jiQy
i
iQx
i
iPy
i
iPx
i
t
cossincossinsincossincos
sincossincoscossincossin
2,
Φ
100100
2,
Q
i
P
ij
P
j
Q
i
P
ij
P
jQ
i
P
i
Q
i
P
i
Q
i
P
ii
P
j
Q
i
P
ii
P
jQ
i
P
i
Q
i
P
ir
yyyy
xxxx
xxyy
yyyy
xxxx
xxyy
qΦ
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ27
Kinematics SimulationKinematics Simulation
Computer Implementation
Examples
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ28
Dynamics SimulationDynamics Simulation
Constraint Dynamics
Lagrange multipliers
Velocity transformations
Numerical integration
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ29
Lagrange MultipliersLagrange Multipliers
The general form of equations of motion
using Lagrange multipliers is
This equation represents m equations in n unknowns, it is
necessary to give n more equations, a possibility are
acceleration equations
Equations to solve
QλΦqM
q
T
c
Q
λ
q
0Φ
ΦM
q
q
T
( 4 )
( 5 )
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ30
Velocity TransformationsVelocity Transformations
Based on the fact that it is possible to express
equations (5) in terms of a different set coordinates by
a linear transformation (velocity transformation)
Open loop systems
Close loop systems
Lagrange multipliers
Second velocity transformation
pRq pRpRq
pRMQRpMRR
TT
pRMQRμΦpMRR
T
p
T
T
zSMRRzSRMQRSzMRSRS
TTTTT
( 7 )( 6 )
( 8 )
( 9 )
( 10 )
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ31
Numerical vs SymbolicalNumerical vs Symbolical
Model description
Data input
Formalism
Numerical equations
Simulation
Local output
Global result
N
e
x
t
t
im
e
s
t
e
p
M
o
d
e
l
v
a
ri
a
t
io
n
P
a
r
a
m
e
t
e
r
v
a
r
ia
t
io
n
Model description
Data input
Formalism
Symbolical equations
Simulation
Local output
Global result
N
e
x
t
t
im
e
s
t
e
p
M
o
d
e
l
v
a
r
ia
t
io
n
P
a
r
a
m
e
t
e
r
v
a
r
ia
t
io
n
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ32
Dynamics SimulationDynamics Simulation
Lagrange Multipliers
Computer Implementation
Examples
Inverse dynamics
Direct dynamics
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ33
Dynamics SimulationDynamics Simulation
Velocity transformations
Computer Implementation
Examples
Inverse dynamics
Direct dynamics
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ34
Simulation using WEBSimulation using WEB
WEB Server
Active Pages
Java/JavaScript
Nobember 4th to 7th, 20031st International Course on Robotics, UNIVERSIDAD NACIONAL DE INGENIERÍA, Lima PERÚ35
References 1References 1
Cuadrado, J. et.al. “Modeling and Solution Methods for
Efficient Real-Time Simulation of Multibody Dynamics”,
Multibody Systems Dynamics, Vol. 1, No. 3, 1997.
García de Jalón, J. and Bayo E., Kinematic and Dynamic
Simulation of Multibody Systems, The Real-Time
Challenge, Springer-Verlag, 1993.
Schiehlen, S., “Multibody Systems Dynamics: Roots and
Perspectives”, Multibody Systems Dynamics, Vol. 1, No.
2, 1997.
Shabana, A., Computational Dynamics, Wiley, 1994.