Fundamentals of Vehicle
Design
Dr. Shirish P Patil &
Dr. Kamarul Tawi
Course Objectives
• Understand vehicle manufacturing organization
• Understand vehicle development process
• Understand vehicle systems and attributes (properties)
• Learn to set performance specifications for a new
vehicle
• Understand system/component contribution towards
vehicle performance
• Learn to set specifications for system/component design
• Learn to design components to meet specifications
Course Outline
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12.
Overview of vehicle design process
Vehicle performance specifications
Vehicle acceleration & powertrain design specification
Vehicle deceleration & brake design specification
Vehicle ride & chassis design specification
Vehicle roll-over & chassis design specification
Vehicle handling & chassis design specification
Vehicle durability & chassis design specification
Vehicle crash safety & body design specification
Design of the suspension system
Design of the steering system
Design of the body/door system
Course Schedule
• Every Tuesday: classroom instruction (2 hours)
• Every Thursday: group project discussion (3 hours)
• Study time: approximately 4 hours/week
Evaluation Criteria
• Final written project report including
weekly log of activities (40%)
• Final project presentation (15%)
• Mid-term project presentation (5%)
• Team participation & contribution (40%)
Team Participation & Contribution Evaluation
No.
Performance
Criteria
Level 1
Level 2
Level 3
Level 4
Level 5
1.
Contributions
Does not
provide ideas
when
participating in
the group
discussion.
Rarely provides
ideas when
participating in the
group discussion.
Sometimes provides
ideas when
participating in the
group discussion. A
satisfactory group
member who does
what is required.
Usually provides
useful ideas when
participating in the
group discussion.
A strong group
member who tries
hard.
Routinely provides
useful ideas when
participating in the
group discussion. A
leader who
contributes a lot of
effort.
2.
Effort in Problemsolving
Does not try to
solve problems
or help others
solve problems.
Lets others do
the work.
Rarely tries to
solve problems or
help others solve
problems.
Does not suggest or
refine solutions, but
is wiling to try out
solutions suggested
by others.
Refines solutions
suggested by
others
Actively looks for
and suggests
solutions to
problems.
3.
Attitude
Always publicly
critical of the
project or the
work of other
members of the
group. Has
negative attitude
about the
task(s).
Is often publicly
critical of the
project or the work
of other members
of the group. Is
often negative
about the task(s).
Is occasionally
publicly critical of the
project or the work
of other members of
the group. Usually
has a positive
attitude about the
task(s).
Is rarely publicly
critical of the
project or the work
of others. Often
has a positive
attitude about the
task(s).
Is never publicly
critical of the project
or the work of
others. Always has a
positive attitude
about the task(s)
4.
Participation and
Working with
Others
Does not
participate,
listen to, shares
with, and
supports the
efforts of others.
Is not a good
team player.
Rarely participate,
listens to, shares
with, and supports
the efforts of
others. Often is not
a good team
player.
Often participate,
listens to, shares
with, and supports
the efforts of others,
but sometimes is not
a good team
member.
Usually participate,
listens to, shares,
with, and supports
the efforts of
others. Does not
cause ”ripples” in
the group.
Almost always
participate, listens
to, shares with, and
supports the efforts
of others. Tries to
keep people working
well together.
Project Description
• Each team (5 students) will choose a
passenger vehicle to be engineered
• Team will decide the performance
specifications for the vehicle
• Team will design the specifications for the
powertrain/brake/suspension/body system
so that vehicle specifications are satisfied
Requirements for the Report
• List of specifications for cost, weight, acceleration,
braking, ride, handling, roll-over, crash safety and
durability. Method of setting each specification
• Design of powertrain system properties to meet
acceleration specification
• Design of brake system properties to meet braking
specification
• Design of suspension & steering system properties to
meet ride, handling, roll-over and durability specification
• Design of body system properties to meet crash-safety
specification
• Design of door system properties to meet door closing
effort specification
Vehicle Classification
Vehicle
Type
Body Style
Power Train
Suspension
Passenger Car
2D/3D/4D/5D UniBody
Engine: 1.0-3.0L
Trans: 5spd/Auto
Driveline: FWD
Front: McPherson
Rear: Multi-link
MPV
4D/5D UniBody
Engine: > 2.0L
Trans: Auto
Driveline: FWD
Front: McPherson
Rear: Multi-link
SUV
5D Unibody or Body on
Frame
Engine: 1.8-5.0 L
Trans: Auto
Driveline:
FWD/RWD/AWD
Front: McPherson/SLA
Rear: Multi-link/Solid Axle
Luxury Car
4D Unibody or Body on
Frame
Engine: >2.5 L
Trans: Auto
Driveline: FWD/RWD
Front: SLA
Rear: Multi-link
Sports Car
2D/3D Unibody
Engine: >3.5 L
Trans: 5Spd
Driveline: RWD
Front: McPherson
Rear: Multi-link
Pickup Truck
2D/4D Body on Frame
Engine: >2.5 L
Trans: Auto
Driveline: RWD/AWD
Front: SLA
Rear: Solid Axle
Commercial
Truck
2D Body on Frame
Engine: >5 L
Trans: Auto
Front: SLA
Rear: Solid Axle
How to prepare vehicle
specifications?
• Understand what your customer desires
• Understand what your competition offers
• Understand government regulation
Team Exercise
• Pick a vehicle you plan to design
• Write vehicle specifications by studying 2
or more competition vehicles (study dealer
specs., do internet search, etc.)
Cost Specification
• What is the intended selling price of the
car?
• How many units do you plan to sell?
• Will you make any profit?
Weight Specification
• What is intended gross vehicle weight
(GVW)?
• How many passengers?
• What is the luggage capacity?
• Weight distribution?
Geometry Specification
•
•
•
•
Wheelbase?
Tread?
Ground clearance?
Tire size?
Acceleration Specification
• 0 to 100 km/h in how many seconds?
• Engine torque/power?
• Transmission speed? Auto or Manual?
Braking Specification
• Deceleration level required?
• Stopping distance from 100 km/h?
• Dry surface/Wet surface?
Ride Specification
• Desired ride frequency?
• Desired passenger acceleration on an
average road surface?
Roll-over Safety Specification
• What is the max lateral acceleration the
vehicle will sustain?
Handling Specification
• Minimum turning radius?
• Understeer or oversteer?
• Steer gradient?
Durability Specification
• What is the desired life of a suspension
component?
Crash Safety Specification
• What is the average deceleration
experienced during frontal crash?
Organization of an Automaker
Suppliers
Vehicle
Engineering
Manufacturing
&
Assembly
Leadership
Finance
Sales
&
Marketing
After
Sales
Service
Dealer
Network
Concept to Customer Process
Customer
Requirements
Vehicle
Program
Regulations
Vehicle
Engineering
Manufacturing
&
Assembly
Sales
Service
Organizational Responsibility
Organization
Responsibility
Examples
Central
Leadership
Run the company profitably
Provide leadership for the future
Provide initiatives to build
Eco-friendly cars
Finance
Raise & provide funds to run
operations
Provide loans to
customers for purchasing
vehicles
Vehicle
Engineering
Engineer the vehicle to meet
customer specifications and
regulatory requirements
Design & test parts and
vehicles to meet specs.
Manufacturing &
Assembly
Manufacture parts & assemble
vehicles
Manufacture stamped
body panels & engine
castings
Sales & Marketing Gather customer specifications
Set customer wants
After Sales
Service
Provide after sales customer
service
Ensure availability of
replacement parts
Dealer Network
Sell & service cars
Suppliers
Manufacture parts & assemble
Design/test/manufacture
Vehicle Development Organization
Vehicle
Development
Organization
Product
Engineering
Body Engineering
Chassis Engineering
Powertrain Engineering
Climate Control Engineering
Electrical Engineering
Vehicle
Engineering
Package Engineering
Weight Engineering
Safety Engineering
Vehicle Dynamics
Vehicle Durability
Vehicle NVH
Vehicle Thermal&Aero
Prototype Planning/Test
Styling
Exterior Styling
Interior Styling
Product Engineering
Organization
Responsibility
Body Engineering
Develop exterior sheet metal and interior trim to meet
engineering and cost specifications
Chassis Engineering
Develop suspension/steering/brake/frame system
components to meet engineering and cost specifications
Powertrain Engineering Develop engine/transmission/driveline/fuel/exhaust system
components to meet engineering and cost specifications
Climate Control
Engineering
Develop HVAC system components to meet engineering
and cost specifications
Electrical & Electronic
Engineering
Develop electrical/electronics/entertainment system
components to meet engineering and cost specifications
Vehicle Engineering
Organization
Responsibility
Package Engineering
Ensure all systems and components fit in the vehicle
Weight Engineering
Ensure all systems and components meet weight spec.
Safety Engineering
Ensure that the vehicle meet the regulatory safety spec.
Vehicle Dynamics
Ensure that the vehicle meet the regulatory/customer ride
& handling spec.
Durability Engineering
Ensure that the vehicle meet the customer durability spec
Vehicle NVH
Ensure that the vehicle meet the customer Noise,
Vibration & Harshness spec.
Prototype Planning/Test Plan & manage prototype builds and testing
Styling
Organization
Responsibility
Exterior Styling
Develop exterior sheet metal Class I (Styled)
clay surface
Interior Styling
Develop interior trim Class I (Styled) clay
surface
Vehicle Development Process
Vehicle,
System &
Component
Spec
Concept
Evaluation
To
Meet Spec
Program
Approval
Prototype
Design &
Testing
Production
Design &
Testing
Fix Problems
Before
Production
Vehicle Development Process
Process
Outcome
Activities
Examples
Prepare Spec.
Final vehicle,
system &
component spec.
• Hold customer clinics
• Benchmark vehicles
• Study regulations
• 0 to 100 kmph in 9 sec
• Investment cost < $ 500M
• no structural failure < 150,000 km
Concept
Evaluation
Data required to
make decisions
• Design feasibility studies
• Cost feasibility studies
• Is acceleration spec. possible?
• Is investment target possible?
Program
Approval
GO or NO GO
decision
• Program meeting
Prototype Design
& Testing
Data required for
80% confidence
in the design
• Part design
• Manufacturing & Assembly
• Testing
• CAD surface or solid with drawings
• soft tooled part & pilot plant assembly
• CAE/Lab/Proving Ground testing
Production
Design & Testing
Data required for
99% confidence
in the design
• Part design
• Manufacturing & Assembly
• Testing
• CAD surface or solid with drawings
• hard tooled part & plant assembly
• CAE/Lab/Proving Ground testing
Fix Problems
before Launch
100% confidence
• Final fixes by launch team
Vehicle Systems & Attributes
Vehicle
Systems
• Body
• Chassis
• Powertrain
• Climate Control
• Electrical
Attributes
• Cost
• Weight
• Package
• Safety
• Dynamics
• Durability
• NVH
•Styling
Function of Vehicle Systems
Vehicle System
Function
Body
• Provide durable attachment for other major systems
• Provide safe and pleasant seating environment for all passengers
• Protect passengers from crashes
Chassis
• Provide capability to steer the vehicle
• Provide capability to brake the vehicle safely
• Provide isolation between road and passengers
Powertrain
• Provide capability to accelerate the vehicle by transferring torque to wheels
• Provide capability to control vehicle speed
• Meet regulatory exhaust requirement
Climate Control
• Maintain comfortable temperature distribution for passengers
• Provide windshield defrost capability
Electrical & Electronics
• Provide power supply where needed
• Provide desirable entertainment system
• Provide functional censors and controls
Vehicle Attributes
Vehicle Attributes
Description
Cost
Lowest production, assembly and distribution cost compared to
competitive vehicles
Weight
Lowest curb weight compared to competitive vehicles in its weight class
Package
Best use of the space to provide comfort and amenities to passengers
Safety
5* crash rating from the Federal Motor Vehicle Safety Standard (FMVSS)
Dynamics
Best ride & handling performance compared to competitive vehicles
Durability
Highest reliability and high mileage durability compared to competitive
vehicles
NVH
Lowest noise, vibration and harshness compared to competitive
vehicles