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Automotive Design

with Respect to

Ergonomics

Ehsan Naseri 81178607Soudeh Yektaee 81195404

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Content What is Design? Design Process Design process For Automotive Design process For automotive

with respect to Human Factors

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Introduction to Design A goal- directed problem solving activity (Archer 1965).

Design is a interplay between what we want to achieve and how we want to satisfy them (Suh 1990).

Design is a process of converting information that characterize the needs and requirements for a product into knowledge about the product (Mistree 1992).

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Definition of Design

Design is

– An art, not a science • Problem solving, Decision making, Applying science

– Creativity & imagination vs Heuristic search– Directing, leading & organizing

• Dealing with people & team-building • Negotiating to achieve a satisfactory solution &

optimizing • Foresight towards production, assembly, testing and

other processes• Considering the "bottom line" of costs and profit, • Satisfying needs & satisfying the customer

– Ethical and professional conduct

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Various Design

New Design: New tasks and problems are solved by new solution principles.

Revised Design: The embodiment design is customized/adapted to fit new requirements. The employed solution principles are known and field-proven .

Variant Design: Size and/or structure of parts and assemblies are varied within the limits of the already planned system.

Repeat Design: A new start of the production run with an unchanged design.

Robust design: A systematic engineering based methodology (which is part of quality engineering process) that developes and manufactures high reliability products at low cost with reduced delivery cycle.

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Over the Wall EngineeringProduct concept Product specs. Design specs. Manufacturing specs.

Customers Marketing Designengineering

Manufacturing engineering

Production

Roles of system engineerNeed identification & customer linkage, Management (spec, process, risk, information), System design, Integration, R&D, leading & coordinating

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Integrate Product Design

DesignDesign

R&DR&D

FinanceFinance

MarketingMarketing

CustomersCustomers

ManufacManufac--turingturing

SuppliersSuppliers

DesignDesign

R&DR&D

FinanceFinance

MarketingMarketing

CustomersCustomers

ManufacManufac--turingturing

SuppliersSuppliers

Integrate People– Build concurrent engineering teams– Negotiation in engineering design

Integrating Processes– Process Modeling– Process Reengineering

Integrating Information– Database Management Systems– Information and data mining

Building a Concurrent Engineering Design Process

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Design Process

System, subsystem and component design Sequential & iterative process Starts and Ends with the customer Comparison and contrast to scientific method

– Need Concepts Feasibility Produce Sell– Time and cost as key factors

Process of converting information that characterizes the needs and requirements for a product into knowledge about the product and its implied processes.

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Engineering Models of Design

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Design process 1

Recognition of a customer’s need– Market research identifies customers and needs– R&D creates ideas that are relevant to an organization’s capabilities– Needs arise from dissatisfaction– Technology push (examples : computers, audio)

Definition of a problem or Task– Design specification– Selecting product ideas– Compiling the requirement list– Acquire & apply technical knowledge– Identify resources– Prioritize design goals & continue to refine

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Designs vs Needs

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Design process 2

Product definition– Function– Preliminary requirements list– Solution requirements – Cost target and budget

SOURCES

CONSUMER COMPANY

SITUATION ANALYSIS

PROCEDURE FOR SEARCH

DEFINE THE PRODUCT

QUALITATIVE DESCRIPTION

DESIGN

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Design process 3

Conceptual design– This phase looks at the function requirement of the Product.The

function are listed & complex functions are broken into simpler sub-functions.

– Determines the Principle of Solution.– It is preceded by a Decision

Procedure– Abstract to identify essential problems– Establish function structures– Search for working principles to fulfill the sub-functions– Combine working principles into working structures– Select suitable combinations– Evaluate against technical & cost criteria

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Design process 4

Design embodiment– It starts from the concept and develops the definitive layout for the

project– Evaluate against Technical & Economic criteria– Preliminary layout– Optimize and complete form designs– Check for errors and disturbing factors– Prepare preliminary part list and production documents

Embodiment design is characterized by repeated deliberation and verification.

This requires approach that is progressive as well as iterative. The checklist

– Function, Working Principle, Layout, Safety, Ergonomics, Production, Assembly, Transport, Recycling, Maintenance, Costs, Quality control

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Design process 5

Prepare production documents :– Elaborate detailed drawings and parts list– Complete production,assembly,transport and operating

instructions– Check all documents

Design review– Review and redesign focuses on achieving the performance,

producibility, reliability and cost (As compared to what) objectives.

– Competitive benchmarking– Reverse Engineering of competitor’s products– Early bird gets the profit

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Example design process: Jack

My car was not in very bad condition, but the original jack was so slender, that I didn't dare creep under the car when it was lifted by this jack. There was no space for me, anyway! The floor of the car was badly rusted, because the car had been effected by some sewer gas in the garage. I had to cut large sections out of the floor and cover them with new steel plate.

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Information

Space below of car

Jack point & car size

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Available Means

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List of Demands

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Definition of Problem We must design a jack, which is able to lift a car, which has a

weight of 1300 kg, a width of 1800 mm an a wheel base of 2700 mm. The jack must be safe enough, that repair and service operations below the lifted car are possible.

We must design a system, which makes repair and service operations possible below a car.

Functions

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Decomposing into subsystemOnes muscle power has to be transformed to lifting force with the sub function 1. Sub function 2 is used to transmit the combination of lift and lifting force directly or in transformed form into the connection points of the car. Sub function 3 makes the connection with the car. Sub function 4 keeps the system steady on the ground. Sub functions 5 and 6 secure the lift and they make operations below the car safe.

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Alternative subsystems

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Possible combinations

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Decision Table

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Embodiment design

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Detail design

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Review of Design

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Results

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AutomotiveDesign

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Aspects of Designing Car

Occupant Packaging Computer-Aided Ergonomics Design Of car Visual Aspects in vehicle Design Automotive Seat Design for sitting comfort Physical Aspect of Car Design Design of symbols for automobile Control and

Displays Informational aspect of vehicle Design

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Occupant Packaging

Workspace Anthropometry :– Conventional Static Measurements anthropologist(are taken on the human body in rigid , standarized position)

– Functional Task Oriented Measurements Engineer Designer(are taken with the human body at work , in motion or in

workspace attitude and typically are expressed as 3 dimensions.)

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Occupant Packaging

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Occupant Packaging

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Occupant Packaging

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Occupant Packaging

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Occupant Packaging

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Driver workspace design and

evaluation models Task Oriented Percentile

Models

- Use anthropometric data to Define a user population startified across stature , weight and…

- Conduct test for specific task(reach, eye location) to develop statistical models defining spatial requirements

Manikin Oriented Models

- Uses anthropometric data to define 95 percent male and 5 percent female

- uses manikins or selected large (95%) male and small (5%) female to define spatial requirements

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- Assume that sample populations defined user requirements

- assumes user needs are expressed by a central tendency with exclusion at both ends , for example 95 percent accommodation

with 2.5 percent excluded at each end.

- Assume that Specified large males and small female comprehend all user requirements

- Assume that 2-D (or 3-D) manikins can predict or model human requirements

- Assume that a given percentile person is definable from the some of parts

Driver workspace design and

evaluation models

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- many level of accommodation are described , but only for the task studied

- Results in well defined statistical model that defines accommodation levels for specific task

- Many task are measured and evaluated , but only for a defined small and large user

- Result in questionably defined geometric manikin models that predict accommodation for only two extreme percentile people

Driver workspace design and

evaluation models

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Computer Aided Ergonomic Design of automobile

engineers will simulate driver behavior and measure key criteria such as reach, visibility, comfort, posture, biomechanics, strength and anthropometrics. This analysis will enable the team to make driver-oriented decisions about cockpit design, while respecting the overall aerodynamics of the racecar body.

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Simulation with computer

To optimize cockpit ergonomics, engineers will first create a digital model of each driver using a combination of laser scanning and manual anthropometrical techniques. The resulting virtual models will be used to analyze and improve specific accommodation issues such as driver comfort and security, and accessibility and serviceability of components inside the cockpit during pit stops—without the need to involve the actual drivers.

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The SAMMIE System

The SAMMIE system is a computer based Human Modeling tool. Its capabilities make it an invaluable tool to designers and design teams working on products that are used by people. The system offers the following advantages:

3D analysis of fit, reach, vision and posture.

reduced timescale. early input of ergonomics expertise. rapid interactive design. improved communication. cost effective ergonomics

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Automotive Seat Design For Sitting Comfort

kind of motor vehicles:

1. Family and personal business sedan

2. Minivan and off-road vehicle

3. Sport cars

Three different occupants in the vehicle:

1)Driver

2) Front seat passenger

3) Rear set passengers

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Automotive Seat Design For Sitting Comfort

Criteria for a driver s seat : 1: the set should position the driver

with unobstructed vision and within reach of all vehicle control

2: the seat must accommodate the driver s size and shape

3: the seat should be comfortable for extended period

4: the seat should provide a safe zone for the driver in a crash

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Why should respect Ergonomics In Design?

SafetySafety in a race car is the art of protecting the human occupant, at whatever cost to the car. Designing the car to be damaged minimally while hindering driver safety is definitely the

wrong approach.So how do we protect the driver? Well first we need to consider the basic physiological weak

points of the human body.

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Safety The diagram above shows that pretty much any part

of the body exposed to the chassis of the race car is at risk. Injuries occur because the body sustains impacts beyond the G (gravities) level that it can sustain.

The brain is particularly succeptible to injury, because it is really just a soft tissue mass stored inside a very solid bone container, the skull. The key to avoiding injury in the brain is to avoid instantaneous decelleration of the skull. That is, when the skull strikes something hard, it decellerates instantaneously. The brain inside unfortunately keeps on moving, causing head trauma.

Neck and spinal injuries also present a serious threat to life and career. These "Connector" type elements in our body are flexible and stretchable, to a point, and can sustain tremendous G loads before breaking. However, depending on angle of impact, they can break rather easily.

Other bone injuries (breakages) are not as life-threatening or career ending, but still are to be prevented. The bones in our arms, legs and spine are designed to be stressed in tension and compression along their length. In the case of impacts they are often stressed in shear or bending, and therefore snap relatively easily

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Safety In Crash First, the driver needs to be supported, so movement under

normal driving is very limited. This means a seat with lateral head support, a head rest, and good lower and upper body lateral support. Most racing seats provide these three elements

Secondly, the car's chassis needs to hold the seat and driver in place, in all situations, driving and crashing. This is of course accomplished with a chassis mount for the seat, and a 5 or 6 point harness.

Thirdly, measures must be taken to prevent intrusion into or the crushing of the driver's limbs and extremities. On formula cars, the problem of suspension wishbones breaking and piercing the driver's legs is solved by anti-intrusion panels that prevent pieces of the car from intruding into the driver's cockpit. As well, the cockpit "Safety cell" needs to be very strong. The "Safety cell" is the last piece of material between danger and the driver, and so should be well constructed, and not prone to collapsing onto the driver.

Finally, the car needs to absorb the energy via structures that are crushable. As stated previously, the human body does not like to be decellerated from 80 or 100 km/h to 0 instantly. Therefore, we need to find a way that "quickly" decellerates the body. The only possibilities on a race car are the structures which surround the driver's safety cell. Designing these structures to collapse in an impact ensures that G levels are reduced because the car is literally decellerating over a small distance, instead of ZERO distance

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Safety/Ergonomics Design Tips

Use energy absorbing materials in the collapsable crash structure - In lower cost racing cars, most of the car is usually built from mild steel. Using that same mild steel in areas such as wishbones means that impacts will bend the material long before it breaks the material, meaning energy absorption takes place over a longer period.

For light weight, use a stressed skin over a lightweight core material - crushable zones such as the nose cone on a formula car can be made from balsa, honeycomb or high density styrofoam covered with a stressed skin of composites.

Triangulate the driver "safety cell" to prevent collapse - The safety cell can be designed in such a way that a catastrophic impact which collapses the safety cell, will make the safety cell expand away from the driver, instead of collapsing it onto the driver. In the case of a frontal impact, this would mean the sides of the cockpit would expand outward, upward and downward, instead of inward.

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Use a clear windscreen or bodywork to increase vision - using lexan or other non-shattering clear material can help increase visibility without compromising the function of the bodywork. In some cases, the driver can be lowered for better CG (center of gravity), and the normally opaque bodywork replaced with clear lexan, to aid in re-establishing the vision field.

Keep the fuel cell and battery away from the driver and danger. Keeping dangerous items away from the driver is sometimes very difficult. In order to reduce the weight balance change over a race, designers will frequently put the fuel cell at the CG, so that no matter how empty or full it is, it does not cause a front/rear or side-to-side weight bias. However, most drivers don't like to sit next to fuel. Use secured, sealed firewalls between the fuel cell and driver compartment, and further, use the safety cell to protect the fuel cell from outside intrusions.

Don't scrimp on safety. Use only top quality certified suppliers of safety equipment. The cost is perhaps high, but consider how much you value your life. Fuel cells (Sanctioning body certified), seat belts (5 or 6 point sanctioning body certified only!), and driver safety wear (Nomex, 2 or more layers minimum! -- anything less is like wearing nothing).

Safety/Ergonomics Design Tips

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Design Of Symbols For Automobile Control and Displays

1) Digital meters Discreet digital meters maximize forward visibility and help create a sense of uncluttered spaciousness.

2) Triangle-motif steering wheel The triangle-motif steering wheel helps harmonize exterior and interior design, for a feeling of unity throughout.

3) Centrally positioned audio panel A 2DIN opening for audio components is centrally positioned at the top of the instrument panel for easy access and visibility.

4) Textured dashboard and console The dashboard centre, floor console, and front pillars are trimmed with a new textured material with a refined look and feel.

5) Sporty two-tone fascia The sporty two-tone fascia adds a touch of pizzazz to the Liana's interior.

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Displays

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Displays

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Displays

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Displays

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Reading assignment

Aesthetics and Engineering Design– http://design.stanford.edu/PD/kbase/Aesthetics_and_Engineering_Design.pdf

Introduction of design – http://deed.ryerson.ca/DesignScience/1.html

design basics in IT– http://www-3.ibm.com/ibm/easy/eou_ext.nsf/Publish/6

user engineering in IT– http://www-3.ibm.com/ibm/easy/eou_ext.nsf/Publish/1996

Automotive Ergonomics Brayan Peacock & Waldemar Karowski Sitting posture E. Granjin

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