universal mechanism simulation of dynamics of road vehicles in universal mechanism software...

Universal Mechanism

Simulation of dynamics of road vehicles in

Universal Mechanism software

www.umlab.ru um@umlab.ru

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 um@umlab.ru

Thanks for your kind attention