Universal Mechanism Simulation of dynamics of road vehicles in Universal Mechanism software www.umlab.ru [email protected] Universal Mechanism
Universal Mechanism
Simulation of dynamics of road vehicles in
Universal Mechanism software
www.umlab.ru [email protected]
Universal Mechanism
Universal Mechanism
Contents
Background
Road vehicle as a mechanical system
Creating models
Simulation of vehicle dynamics
Verification
Universal Mechanism
Background
Kinematics of cars
Road vehicle components
Universal Mechanism
Engine
Universal Mechanism
Off-road vehicle
Universal Mechanism
Transmission components
Differential
Cardan shaft
Universal Mechanism
Grader
Grader GS 18-05 byBryansk factory of road machines.
Velocity: 40 km/hPavement: asphalt in satisfactory condition
Author: Vlad Govorov, BSTU, Bryansk, Russia
Universal Mechanism
VAZ 2109
Dynamic test: vertical load
Universal Mechanism
UM Caterpillar
Simulation results
Universal Mechanism
UM Caterpillar
Simulation results
Universal Mechanism
Truck/trailer
SAE lane change, V=88 km/h
Universal Mechanism
B-double
Low-speed 90º turn, V=10 km/h, R=11.25 m
Universal Mechanism
Pulse steer
Pulse steer, V=100 km/h
Universal Mechanism
Step steer
Step steer, V=100 km/h
Universal Mechanism
Three-wheeled light vehicle (1)
Double lane change, V=14 km/h
Universal Mechanism
Three-wheeled light vehicle (2)
Double lane change, V=14 km/h
Universal Mechanism
Student work
Single-cylinder engine
Universal Mechanism
Student work: cart
Police turn
Universal Mechanism
Student work: police turn
Police turn
Universal Mechanism
Student work: drifting
Drifting
Universal Mechanism
Contents
Background
Road vehicle as a mechanical system
Creating models
Simulation of vehicle dynamics
Verification
Universal Mechanism
Simulation workflow
Real mechanical system or its prototype
Preparing input data and conception of a model
Describing kinematical model
Describingdynamical model
Automatic generation of equations of motion
Analyzing model’s dynamical performances
tqqQqqkqqM ,,,
Universal Mechanism
Technical objects as multibody systems
Bodies+
Joints+
Force elements
Universal Mechanism
Rigid bodies
Rigid body:• Image
• Inertial parameters
Universal Mechanism
Joints
Joints
Translational Rotational
2 - 6 d.o.f. joints Quaternion
Rod
Universal Mechanism
Force elements
For Hendrickson Pacific Ltd.
Damper
Air spring
Bushing
Bushing
Universal Mechanism
Force elements
0
10000
20000
30000
40000
50000
60000
0.15 0.17 0.19 0.21 0.23 0.25 0.27 0.29
Length, m
Fo
rce,
NAirspring
Damper
-12000
-10000
-8000
-6000
-4000
-2000
0
2000
4000
-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8
Relative damper velocity, m/s
Fo
rce
, N
Universal Mechanism
Heavy vehicle suspension
Cobblestone pavement, V=100 km/h.
Universal Mechanism
UM FEM: Flexible bodies
For Hendrickson Pacific Ltd. Finite-element model of the leaf spring
Universal Mechanism
UM FEM: principle of operation
Simulation of hybrid system(system of rigid and flexible bodies)
Import of dynamic and static modes from FEM software(ANSYS, MSC.NASTRAN)
FEM-model
from
ANSYS,MSC.NASTRAN
+ =Rigid body model
from
UniversalMechanism
Hybrid model
in
UniversalMechanism
Universal Mechanism
Durability analysis
Workflow
AN
SY
S /
MS
C.N
AS
TR
AN
Un
iver
sal M
ech
anis
m
UM rigid body model
UM hybrid (rigid+flexible)
model
Running series of numerical
simulations
Modal coordinates time history
UM Durability post processing
Results - Stresses - Damage Sum - Life prediction
Finite-element mesh of flexible bodies
Mode shapes according to the
Craig and Bamptone approach
Universal Mechanism
Kompass 3D –> Universal Mechanism interface
Universal Mechanism
SolidWorks –> Universal Mechanism interface
Universal Mechanism
Autodesk Inventor –> Universal Mechanism interface
Universal Mechanism
Matlab/Simulink interface
ψ
F M
m, I
Example 1. Stabilization of the inverted pendulum
Mechanical part
(Universal Mechanism)
Control part (Matlab/Simulink)
ψ
F
Universal Mechanism
Matlab/Simulink interface
Free motion Controlled motion
Example 1. Stabilization of the inverted pendulum
Universal Mechanism
Matlab/Simulink interface: ABS simulation
ABS model in Matlab/Simulink
Universal Mechanism
Braking coefficient / Slip diagram
Kienhöfer, F.W., Cebon, D. Improving ABS on Heavy Vehicles Using Slip Control
Universal Mechanism
Simulation results: vehicle speed
Vehicle speed
with ABS without ABS
Universal Mechanism
Simulation results: with ABS
Universal Mechanism
Simulation results: without ABS
Angular velocity Longitudinal slip
Universal Mechanism
Simulation in Matlab
Universal Mechanism
Contents
Background
Road vehicle as a mechanical system
Creating models
Simulation of vehicle dynamics
Verification
Universal Mechanism
Creating models (UM Input)
Screen shot of UM Input program
Tree of elements
IdentifiersInspector
Universal Mechanism
Equations of motion
Deriving equations in symbolic form using a built-in computer algebra
system (C, Pascal codes)
Numeric-iterational generation
very fast!
…………………………………………………………. _Frc_Vctr[1] := _._ap[3]*_.ix+_._ap[3]*_.mass*_._c2* _._c3*_.length*_.length+_._ap[3]*_.mass*_._c3*_.length*_.length-_._ap[3]*_.mass*_.length*_.length* _._s2*_._s3+ _._ap[3]*_.mass*_.length*_.length-0.1634* _._ap[3]*_.mass*_._c2*_._c3*_.length-0.1634*_._ap[3]*_.mass*_._c3*_.length+0.1634* _._ap[3]*_.mass*_.length*_._s2*_._s3-0.3268* _._ap[3]*_.mass*_.length+0.02669956*_._ap[3]*_.mass +2*_._ap[2]*_.ix+_._ap[2]*_.mass*_._c2* _._c3* _.length*_.length+2*_._ap[2]*_.mass*_._c3*_.length* _.length +2*_._ap[2]*_.mass*_._c2*_.length *_.length-_._ap[2]*_.mass*_.length*_.length*_._s2*_._s3………………………………………………………….
Elements of equations are computed on each step of numeric integration
Automatic generation of equations of motion
Generation of equation in symbolic form and the following compiling them as DLL is one of the reason why UM is faster that many other software
also implemented in UM (sometimes very useful)
Universal Mechanism
Contents
Background
Road vehicle as a mechanical system
Creating models
Simulation of vehicle dynamics
Verification
Universal Mechanism
Analysis of Models (Simulation Module)
Screenshot: Simulation ModuleAny number of animation and plot window
Universal Mechanism
Simulation
Simulation: on-line visual representation of results• 3D animation of motion
• 3D animation of vectors (forces, velocities, accelerations)• 3D animation of trajectories
• plots (coordinates, velocities, accelerations, applied and reaction forces etc.)
Expander: direct dynamic problem
Universal Mechanism
Simulation tools
Processing of VariablesEvery computed variable from graphical window or from list of variables can be processed with
•Table processor• Window of statistics
Universal Mechanism
Simulation tools
Original Filtered
Universal Mechanism
Steering wheels
Cobblestone pavement, V=100 km/h.
Universal Mechanism
UM Automotive: tire models, library of suspensions
Tire models
Pacejka Magic Formula
Pacejka Magic Formula
FIALA tiremodel
FIALA tiremodel
Tabular and experimental tire
models
Tabular and experimental tire
models
Road excitations
Pointwise input(for measured data)
Pointwise input(for measured data)
Analytical expressions
Analytical expressions
Synthesis of the road profile based on its
spectral power density
Synthesis of the road profile based on its
spectral power density
Superposed pointwise/analytical/generated by spectral power density road profile
Superposed pointwise/analytical/generated by spectral power density road profile
Library of spectral power density of typical road surfaces
Library of spectral power density of typical road surfaces
Universal Mechanism
UM Automotive: maneuvers
Maneuvers with closed-loop steer control
Trajectory+
Driver model(MacAdam’s model, Second order preview model)
Trajectory+
Driver model(MacAdam’s model, Second order preview model)
Universal Mechanism
Eigenmodes
0,40 Hz
1,10 Hz
0,82 Hz
1,39 Hz
Universal Mechanism
Contents
Background
Road vehicle as a mechanical system
Creating models
Simulation of vehicle dynamics
Verification
Universal Mechanism
Heavy Vehicles
National road transport commission of Australia
Model 1: B-double
Model 2: Truck-trailer
• ADAMS CAR• UMTRI’s Yaw/Roll• AUTOSIM
• Universal Mechanism
SAE Lane change, 88 km/h
Universal Mechanism
Simulation results: pulse steer
ADAMS
Yaw/Roll
AUTOSIM
UM
Universal Mechanism
Simulation results: pulse steer
ADAMS
Yaw/Roll
AUTOSIM
UM
Universal Mechanism
Simulation of dynamics of road vehicles in
Universal Mechanism software
www.umlab.ru [email protected]
Thanks for your kind attention