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Copyright ITI GmbH 2008 Page 1 SIMULATION SOFTWARE ENGINEERING www.SimulationX.com Analyzing Gear Shifting and its Interaction with Vehicle Dynamics in
Copyright ITI GmbH 2008 Page 1
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Analyzing Gear Shiftingand its Interaction with Vehicle
Dynamicsin
Copyright ITI GmbH 2008 Page 2
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Overview
1. Introduction2. Vehicle Model in SimulationX
OverviewFront AxisSteering Kinematics and ControlRear AxisGearboxRear Axle TransmissionEngine, Clutch, and Vehicle ControlEfficient Sub-Structuring
3. Results
Copyright ITI GmbH 2008 Page 3
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Introduction
Objective:
Analyzing of gear shifting in MTs or AMTs and its interaction with vehicle dynamics
Requirements:
Specialized modeling and simulation approaches Multi-domain simulation (MBS, Control Systems, …)
Results:
Satisfactory and holistic solutionsImprovement in vehicle dynamics as well as comfortable gear shifting processes
Copyright ITI GmbH 2008 Page 4
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Combination of various subsystems within one model:Multi-Body systems (local and global coordinates)1D Mechanics (only local coordinates)Control / actuation systemsHydraulic, pneumatic, electric, thermal effects can be considered
Example: Vehicle model including:Independent, detailed wheel suspensions, springs and shock absorbers,Shiftable gearbox (automated manual transmission (AMT)),Engine, clutch, rear differential,Engine model (based on engine map), andControl systems for engine, gear shifting, clutch, and steering
Copyright ITI GmbH 2008 Page 5
SIMULATION
SOFTWARE
ENGINEERING
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Vehicle Model
Front WheelsIndependent, detailed wheel suspensionSpace Arms suspension kinematicsConnection of the steering mechanism
3D View Diagram View
suspension kinematics Tire-ground contact
shock absorberand spring
steering kinematics
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SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Steering kinematics and control (driver)linkage mechanism of the steering system
3D View Diagram View
steering kinematics
suspension kinematicssteering control
Copyright ITI GmbH 2008 Page 7
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Rear AxleIndependent, detailed wheel suspensionDouble wishbone linkage
3D View Diagram View
shock absorber
suspension kinematics
tire ground contact
Copyright ITI GmbH 2008 Page 8
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Shiftable 6 Speed Automated Manual Transmission3D View
Diagram View
output shaft
synchronizers
input shaft
animation bodies
Copyright ITI GmbH 2008 Page 9
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Rear Axle Transmission and Differential3D View
Diagram View
gearbox output shaft
gearbox input shaft
MBS structures
drive shaft (cardan shaft)rear axle transmissionanddifferential
elastic side shafts
Copyright ITI GmbH 2008 Page 10
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Engine, Clutch and Vehicle Control
gearshift controlVehicle
control (accelerator pedal, desired gear, clutch, etc.)
Diagram View
Engine model
clutch with torsional damper
Copyright ITI GmbH 2008 Page 11
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Vehicle Model
Efficient sub-modeling (Example: Gearbox)Diagram View
Summarize sub-structures into compounds, e.g. as assemblies corres-ponding to real components such as the gearboxBetter handling / overview of the complete modelEfficient parameterization
Copyright ITI GmbH 2008 Page 12
SIMULATION
SOFTWARE
ENGINEERING
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current_gear - gearboxC ontrol1
0
1
2
3
4
5-
0 20 40 60 80 100
s
om - gearbox_in
-1000
0
1000
2000
3000
4000
5000rpm
0 20 40 60 80 100
s
om - gearbox_out
-100
0
100
200
300
400
500
600rad/s
0 20 40 60 80 100
s
Results
current gear
gearbox input
and
output shaft speeds
Copyright ITI GmbH 2008 Page 13
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Ti - side_shaft2
-1000
0
1000
2000Nm
0 10 20 30 40 50 60
s
F i - springDamperRL
-7000
-6000
-5000
-4000
-3000N
0 10 20 30 40 50 60
s
F i - springDamperFL
-10000
-9000
-8000
-7000
-6000
-5000N
0 10 20 30 40 50 60
s
Results
side shaft torque
internal force of the spring and shock absorber (rear left)
internal force of the spring and shock absorber (front left)
Copyright ITI GmbH 2008 Page 14
SIMULATION
SOFTWARE
ENGINEERING
www.SimulationX.com
Summary
Efficient modeling in several phyiscal domainsMulti-domain model of a vehicle and transmission incl. MBS, 1D driveline model and control structuresEfficient sub-modeling by creating compounds of assemblies as in the real vehicle (e.g. gearbox)Generation of holistic results using several methods
All-in-one: The Driving Force inSystem Simulation
