Ideation Process - School of Engineering



[pic]

Ideation Processurl_IPS/Ideation_Process.htm

Project Initiationurl_IPS/IPS/1_Project.htm

Project name:

Anti-tip system for manual wheelchairs

Project timeline:

September 2007 - April 2008

Project team:

Nick Burjek

Andrew Dawson

Austin Dirks

Katie Gallup

Frank Lamons

Innovation Situation Questionnaireurl_IPS/IPS/2_Isq.htm

Brief description of the situationurl_IPS/IPS/21_Brief_descr.htm

Design a more mobile anti-tip system for manual wheelchairs.

Detailed description of the situationurl_IPS/IPS/22_Sys_App.htm

We have to design a new anti-tip system for wheel chairs. The current system does not give the user a large enough range of motion. Our system must prevent the user from tipping backwards while enabling the user to launch off curbs and reach the "wheelie" position.

Supersystem - System - Subsystemsurl_IPS/IPS/221_Sup_Sub.htm

System name url_IPS/IPS/2211_System_name.htm

The following systemic levels can be considered:

* Wheelchair

* Anti-tip system

* Contact area of the anti-tip system

The primary useful function is to prevent tipping of the wheelchair user.

System structure url_IPS/IPS/2212_System_structure.htm

The anti-tip assembly consists of the following elements:

* Connection to the wheelchair

* Extension towards the ground

* Bend in the bar away from the center of the chair

* Extension towards the back of the chair

* Wheel contact with the ground

Supersystems and environment url_IPS/IPS/2213_System_environment.htm

Other parts of the wheelchair:

* Back wheels

* Axle

* Seat

* Front wheels

* Frame

* Brakes

Other systems nearby

* Ground

* Curbs

* Ramps

Conditions around the system:

* Indoor conditions

* Sidewalks

* Roads

Systems with similar problems url_IPS/IPS/2214_Other_systems.htm

Similar problems exist in other areas where safety systems are needed but not employed at all times. Systems like airbags sense when they are needed and are deployed as neccessary. Rollover bars in cars are positioned as only to be used when the car has reached a "point of no return" and is rolling. Training wheels on a bicycle are also used to allow free motion but to prevent lateral falling. Complicated systems like the Segway Scooter use gyroscopes to prevent backwards tipping. However, this system is too complex for a manual wheelchair design and we are not aware of any simpler system to prevent backwards tipping.

Input - Process - Outputurl_IPS/IPS/222_In_Out.htm

Functioning of the system url_IPS/IPS/2221_Functioning.htm

The primary function of the anti-tip system is to prevent tipping of the wheelchair beyond the range desired by the user.

The problems associated with this design could be solved by increasing the range of motion allowed by the system to include normal use but prevent falling.

System inputs url_IPS/IPS/2222_Input.htm

Mechanical force from the ground

Wheelchair angle

System outputs url_IPS/IPS/2223_Output.htm

Mechanical force against the ground

Cause - Problem - Effecturl_IPS/IPS/223_Cause_Eff.htm

Problem to be resolved url_IPS/IPS/2231_Problem.htm

Increase mobility of the design to allow turning in the wheelie position and eliminate hindrances when launching off curbs.

Mechanism causing the problem url_IPS/IPS/2232_Mechanism_causing_the_problem.htm

The current design is rigid and is unable to engage and disengage as needed.

Undesirable consequences if the problem is not resolved url_IPS/IPS/2233_Undesirable_consequences.htm

The current system results in an unmoving ground contact point that prevents desired motion. Users cannot turn with the small radius achieved in the wheelie position. The tip bar also may cause the user to fall forward by catching on obstacles like curbs. The biggest consequence is that inconvenience drives people to remove the entire system. Without the tip bars the user has no protection against backwards tipping.

Other problems to be solved url_IPS/IPS/2244_Other_problems.htm

Make the system so it is only deployed when uncontrolled tipping occurs.

Past - Present - Futureurl_IPS/IPS/224_Past_Future.htm

History of the problem url_IPS/IPS/2241_History.htm

Current wheelchair technology allows for greater customization of the wheelchair, and makes a tip bar customized to the individual's center of gravity practical. Additionally, as wheelchairs evolve to enable greater mobility, users do not want to be restrained by outdated anti-tip systems.

Pre-process time url_IPS/IPS/2242_Pre_proc.htm

Normal controlled use of the wheelchair.

Post-process time url_IPS/IPS/2243_Post_proc.htm

Time after the user is stopped by the system.

Resources, constraints and limitationsurl_IPS/IPS/23_Resources.htm

Available resources url_IPS/IPS/231_Available_resources.htm

Substance resources:

* Material of the anti-tip system

* Surrounding frame of the wheelchair

* The ground

Field resources

* Force of the ground

* User decided actions

* User weight

Space Resources

* Space within frame of the wheelchair

Time Resources

* Time of normal operation

* Time between tip initiation and crossing of center of gravity threshold

* Time when user is held by tip system

Informational Resources

* Potential for angle sensing

Functional Resources

* Ability of the system to allow sustained reclining position

Allowable changes to the system url_IPS/IPS/232_Allowable_changes.htm

* Drastic changes are allowed

* The system must prevent tipping

* Can add a "smart" electronic component

* System may require customization to user

Constraints and limitations url_IPS/IPS/233_Constraints.htm

* Must not add too much extra weight

* Must allow collapsing of chair for storage

* Reliability

* At least 5 years life span

* Must not require user input

* Must stay within or close to total footprint of the chair

* Must not inhibit desired motion

Criteria for selecting solution concepts url_IPS/IPS/234_Criteria.htm

* System must allow wheelies and curb launching

* System must prevent tipping

Problem Formulation and Brainstormingurl_IPS/IPS/3_Functional_Modeling.htm

Anti-Tip System

[pic]dgr__url_IPS/Diagram.htm

12/5/2007 11:41:48 AM.

Find an alternative way to obtain Tipping backwards that offers the following: provides or enhances Wheelie position for maneuvering does not cause Falling backwards does not require User controls wheelchair.dirtype_1

Resolve the contradiction: The useful Tipping backwards should provides Wheelie position for maneuvering and avoids Falling backwards.dirtype_4

Find a way to eliminate, reduce, or prevent Falling backwards in order to avoid User injury and Wheelchair damage under the conditions of Tipping backwards.dirtype_2

Find an alternative way to obtain Anti-tip system engaged that offers the following: provides or enhances Static position eliminates, reduces, or prevents Falling backwards does not influence Wheelie position for maneuvering and Going off of curbs.dirtype_1

Resolve the contradiction: The useful Anti-tip system engaged should provides Static position counteracts Falling backwards and avoid hindering Wheelie position for maneuvering and Going off of curbs.dirtype_4

3.  Comment on the value of creating a concept map to describe your particular problem.  Comment on the value of the IWB to assist in problem formulation.  Comment on the use of both, rather than just one approach - do they complement each other?

The concept map is able to organize and neatly display the different components, requirements, and goals of the wheel chair anti-tip system. The concept map is a clear, visual representation of the problem. The innovation workbench is useful in defining the design’s requirements in an organized and systematic manner. Furthermore, the problem definition diagram is helpful in that it promotes innovation by revealing a number of different ways of looking at the same problem. In designing our solution, innovation workbench is useful is expanding our creativity to help identify solutions that may have not been otherwise considered.

Both the concept map and innovation workbench are helpful as they complement one another. The concept map allows the designers to see the different components and any inter-relativity between components. Different branches can be added when innovations are generated from the innovation workbench. The innovation workbench is also useful in defining the requirements and system’s process, and it goes even further to systematize and generate multiple perspectives on the same problem. Both exercises will serve as a useful foundation for the design synthesis of the anti-tip system.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download