fundamental of vehicle design
TRANSCRIPT
Fundamentals of Vehicle Design
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 Outline1. Overview of vehicle design process2. Vehicle performance specifications3. Vehicle acceleration & powertrain design specification4. Vehicle deceleration & brake design specification5. Vehicle ride & chassis design specification6. Vehicle roll-over & chassis design specification7. Vehicle handling & chassis design specification8. Vehicle durability & chassis design specification9. Vehicle crash safety & body design specification10.Design of the suspension system11.Design of the steering system12.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%)
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 Problem-solving
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.
Team Participation & Contribution Evaluation
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 ClassificationVehicle Type Body Style Power Train SuspensionPassenger Car 2D/3D/4D/5D UniBody Engine: 1.0-3.0L
Trans: 5spd/AutoDriveline: FWD
Front: McPhersonRear: Multi-link
MPV 4D/5D UniBody Engine: > 2.0LTrans: AutoDriveline: FWD
Front: McPhersonRear: Multi-link
SUV 5D Unibody or Body on Frame Engine: 1.8-5.0 LTrans: AutoDriveline: FWD/RWD/AWD
Front: McPherson/SLARear: Multi-link/Solid Axle
Luxury Car 4D Unibody or Body on Frame Engine: >2.5 LTrans: AutoDriveline: FWD/RWD
Front: SLARear: Multi-link
Sports Car 2D/3D Unibody Engine: >3.5 LTrans: 5SpdDriveline: RWD
Front: McPhersonRear: Multi-link
Pickup Truck 2D/4D Body on Frame Engine: >2.5 LTrans: AutoDriveline: RWD/AWD
Front: SLARear: Solid Axle
Commercial Truck
2D Body on Frame Engine: >5 LTrans: AutoDriveline: RWD
Front: SLARear: 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
LeadershipVehicleEngineering
Sales&
Marketing
Manufacturing&
Assembly
FinanceAfterSalesService
DealerNetwork
Suppliers
Concept to Customer ProcessCustomer
Requirements
Regulations
VehicleProgram
VehicleEngineering
Manufacturing&
Assembly
Sales
Service
Organizational ResponsibilityOrganization Responsibility ExamplesCentral Leadership Run the company profitably
Provide leadership for the futureProvide initiatives to buildEco-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 systems
Design/test/manufacture parts
Vehicle Development Organization
Vehicle Developmen
tOrganization
ProductEnginee
ring
VehicleEngineeri
ngStyling
Body EngineeringChassis Engineering
Powertrain EngineeringClimate Control
EngineeringElectrical Engineering
Package EngineeringWeight EngineeringSafety EngineeringVehicle DynamicsVehicle Durability
Vehicle NVHVehicle Thermal&Aero
Prototype Planning/Test
Exterior StylingInterior Styling
Product Engineering
Organization ResponsibilityBody 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 ResponsibilityPackage 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
ProductionDesign & Testing
PrototypeDesign &Testing
ProgramApproval
ConceptEvaluation
ToMeet Spec
Fix Problems
BeforeProduction
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 Attributes
• Body• Chassis
• Powertrain• Climate Control
• Electrical
• Cost• Weight • Package• Safety
• Dynamics• Durability
• NVH•Styling
Function of Vehicle Systems
Vehicle System FunctionBody • 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