CHAPTER 18 WESTERN WASHINGTON UNIVERSITYnsf-pad.bme.uconn.edu/1995/chapter_18.pdf · the completed AUGIE out of the work cell. ... AUGie Flow Chart ... Western Washington University

CHAPTER 18WESTERN WASHINGTON UNIVERSITY

Department of Engineering TechnologyBellingham, Washington 98225

Principal Investigators:

Kathleen L. Kitto (306) 650-3380 [email protected]

263

264 NSF 1995 Engineering Senior Design Projects to Aid the Disabled

Robotic Manufacture and Design of AUGIECommunication Devices

Designers: Marco Youngberg (head), Sue Bravard (lead), Whitney Koeberle (lead)Client Coordinators: Gale Noble Sanderson

Children’s Neuromuscular ProgramSupervising Professor: Kathleen L. KittoManufixturing Engineering Technology

Western Washington UniversityBellingham, WA 98225

INTRODUCTIONWorking with therapists from St. Joseph’s HospitalsNeuromuscular Program, Western Washington Uni-versity’s Industrial Robotics class developed a port-able device (AUGIE) to give non-verbal children theability to communicate. St. Joseph’s NeuromuscularProgram staff asked the department to design andproduce a portable device that could play multiplevoice messages allowing non-verbal children tocommunicate. Messages or phrases would be re-corded by a parent or therapist such as: “My name isTeresa, “Hello”, “Good-bye”, “Thank you”, “I amhungry”, or “Call for help.” Other messages includephone numbers, bus stops, personal identificationnumbers, or special instructions.

MICROPHONE -

SUMMARY OF IMPACTOne of the essential aspects of the proposed device isthat the messages be easily changed to fit specialsituations. Replaceable icon sheets cover the messagebuttons with easily understandable symbols. The ro-botics team is given the project and tasked to developa product from its initial design to a final workingproduct. AUGIE (for Augmentative CommunicationDevice) is designed by student team members. Spe-cifically built for use by children, the design had to beeasy to use and to understand.

/ COVER PLATE

ICON SHEET

TOP HALF

SPEAKER BOTTOM HALFOF CASE

COMPZ :gk

Figure 18.1. Robotic Manufacture and Design ofAUGIE Communication Devices.

Chapter 18: Western Washington University 265

TECHNICAL DESCRIPTIONThe manufacturability of the product was consideredfrom the inception of the project. The device must besmall, portable and easily accessible, similar in sizeand shape to portable stereos currently available. Theelectronics necessary for operation and its battery re-quirements dictated the minimum size of the device.A prefabricated project box is selected that included a4 AA battery compartment and enough room forelectronic components. So that the children couldcarry the box, a clip is designed and attached to theback of the box to allow it to be attached to a pocket,belt, or shoulder strap. The device is water-resistant.

The exact configuration of the buttons and their corre-sponding message are primary concerns. The finaldesign included 10 large square buttons with pictureicons for each button. A sleeve containing 10 replace-able icons slips between the ten activation switchesand a cover plate. An icon on each button providesimmediate association for the message contained onthe button. A cover plate is added to guide the fingerinto the button as well as separating the buttons fromeach other. The cover plate also allowed a replaceablesleeve of icons to be slipped between the cover plateand the buttons. When new messages are pro-grammed onto the buttons, a revised icon sheet is in-serted.

A total of 40 seconds of recorded messages is ob-tained by using two digital voice chips. To aid inprogra mming the chip address lines and to simplifyoperation, each button is allocated 4 seconds of voiceplayback. This allowed ample time to record tele-phone numbers and other phrases onto each button.Longer messages are produced by using the individ-ual buttons in sequence. To record messages, atherapist or parent pushes a recessed record buttonand the destination button for the message. The re-cessed button is designed to reduce the chance of achild recording over a prerecorded message duringoperation. An internal microphone located near thespeaker samples the message to be recorded.

The electronics package is designed to be roboticallyinserted into the box as one unit. The keyboard con-taining the buttons, decoding chips, speaker and mi-crophone is located on one 3 l/2 ” x 6” double-sidedcircuit board. The main components, including thespeech and Programmable Array Logic (PAL) inte-grated circuit chips are located on a smaller boardthat is mounted to the larger board with l/2” stand-

offs and linked via a 20-pin connector. This packageslips into the box and interfaces with the battery ter-minal to supply power. The key to the electronics de-sign is the ISD 1000A Voice Record & Playback IC.Each speech chip contains 20 seconds of speech timethat can be addressed in 2-second segments. ForAUGIE, these are divided into 4 second long mes-sages. Messages l-5 are contained on Ul, and mes-sages 6-10 are contained on U2. Decoding messageselection and message addressing is done using aPALCE 16V8-25 IC to enable the speech chips andamplifier. The PAL has a operating supply current ofabout 50 mA, and because of this it is held in thenormally off state to increase battery life. The push ofany message button activates the circuitry. The PALwill then outputs the address of the starting positionof that message to the speech chips and activatesaudio amplifier. Circuit timing is provided byCD4538B Dual Precision Monostable (One Shots)multivibrators. These are used to hold the ICs in anoperational state when a message button is pushed.All the one shots are designed to be non-retriggerableso messages do not overlap if two or more buttons arepushed within 4 seconds. The audio amplifier is de-signed for an output gain of 3 and delivers approxi-mately 250 mW to a 16 ohm, 1” Mylar speaker.

Once the electronic design had been tested on thebreadboard, production components were orderedand circuit board layout began. Using P-CADPCCaps and PCCards software, schematic drawingsare transferred into double-sided trace layout patternsand drawings each side plotted for both circuitboards. These drawings are photographed and thenegatives are used to transfer the trace layout ontocopper-clad printed circuit board blanks using aphotochemical process. The boards are etched by sev-eral team members using department etching equip-ment. Because of the inability to produce through-hole plating on campus, vias between the top andbottom boards are soldered by hand using bus wire.Soldering of the components is also done in a manual“push line” with two stations for the keyboard andfour stations for the main board. The reason for thelarge number of stations on the main board is diffi-culty in component recognition and hand soldering ofthe surface mount devices (SMD’s). Since most of theteam members are unfamiliar with electronics pro-duction techniques, the addition of extra stationseliminated the chance of n-&loading of similar com-ponents at any one station.

266 NSF 1995 Engineering Senior Design Projects to Aid 1

For automated assembly, ultrasonically welding thebox and cover plate provided a simple and tamper re-sistant method of joining the plastic components. Thisprocess welded the cover plate to the front of the boxas well as the final joining of the two halves of the boxafter the insertion of the electronics package.

The assembly operation is divided into 4 main com-ponents: the cover plate, the front of the box, the backof the box, and an electronics package. The tops andbottoms are introduced into the workcell by ramps.The electronics package is carried by the conveyorbelt. Cover plates are loaded into a pneumaticallyactuated dispenser. The various cell functions are ac-tivated through the Input/Output (I/O) ports of theASEA controller. A center station is designed andconstructed to hold the AUGIE components through-out the various stages of assembly. This center stationis capable of moving to the ultrasonic welder andwould return to the center area upon completion ofthe welding process. The remainder of the table pro-vided an area for a NC Dyna mill that is located in thenortheast comer of steel table within the Adept workenvelope. After the final product is assembled andwelded the entire product is picked up and depositedinto the packaging area.

An ultrasonic welder is selected to bond the coverplates to the boxes and bond the boxes together. Thisprocess is better suited to automation than chemicalbonding methods. The ultrasonic welder used is a

Disabled

Branson model 901 AES with a capacity of 1000 watts.The horn used is a wedge type with a face width of 3”x 0.125” thick. The welding cycle is initiated by anoutput from the ASEA robot controller. The coverplate dispenser is located in the center of the workarea, adjacent to the center station neutral position.The ASEA robot is tasked with inserting the electron-ics assembly into the box before the second weldingoperation sealed the two box halves and then movingthe completed AUGIE out of the work cell. The bev-eled edge of the box posed the same problem as withthe Adept end effector. Having to also pick up thesmaller electronics assembly with the same end ef-fector added another problem. The result is to use asliding jaw rather than the pinch jaw of the Adept endeffector. Using a small pressure regulator allowed thejaw pressure to be finely adjusted to suit both tasks.A small grove equal in width to the thickness of thecircuit board is machined into the jaws. This allowedthe electronic assembly to be held by the edge of theboard without becoming misaligned or slipping in thejaws. In addition, a microswitch is placed in the groveto provide a signal to the controller that the electron-ics had been correctly grasped. If this signal is not re-ceived when the jaws reached their limit of travel, thecontroller directed the robot to retreat slightly whilecycling the conveyor again. The robot then repeats theelectronics grasp sequence.

Total cost of parts and circuit boards for each deviceis approximately $825.


AUGie Flow Chart

I Adept p&es top inmilling fixture

Dynamill cycle mills top

1coverplate inserted into

center station

1Adept moves top to

center station

I

iAdept places bottom in

center station

1Center station moves toU/S welder postion #l

Center station moves toU/S welder position #2 I

Figure 18.2. AUGIE Assembly Sequence.


LevelPart No. Part Name Quantity

0

111

22

3

3

444

5

55

5555555555555555

4000 AUGie Communication Deviie

2053 Batteries 4-AA2055 Icon Sheet2057 Mylar Film

2051 Battery Clips 290K-ND2047 Electronics Box MDC

#HPdAA 3.6rx5.75x1.w

2045 CoverplateBlack 118” ABS

3049 ClipsBlack 118” A8s

1043 Photo Deveioper 1 gal.1041 Photo Etch Art 1%~.1007 Film

1001 PAL IC PALCE 16 V8H-10SCH

1003 One shot IC hdCUS38BDW1005 ISD 102AG Analog Speech

Chips/Surface Mount1009 P997cMlD (P9949iPBol l-ND)1011 Switches P801OSIND1013 Transistor HMMT593CT-ND1015 Transistor FMMT3004CTNO1017 Speaker PIN25RFOM41019 Resistor 290-825K1021 Capacitor 581-4.7TlO1023 Resistor 290-909K1025 Resistor 569-628A-1 OK1027 Capacitor 140~CC502BilMK1029 Resistor 290-332K1031 stand-off 56 1 -A05001033 Quad 2 AND 51 l-4081 BM1035 Resistor 263-221037 Capacitor 551-l 05F351039 Capscitor 58 l -33TlO

1 Make

411

BUYMakeBUY

4 BUY1 BUY

1 Make

1 Make

BUYBUYBUY

1 BUY

1 BUY2 BUY

1 BUY11 BUY

1 BUY1 BUY1 BUY3 BUY7 BUY2 BUY1 BUY6 BUY3 BUY4 BUY1 BUY2 BUY1 BUY1 BUY

Make/Buy

Figure 18.3. AUGIE Parts List.


Figure 18.4. AUGIE Final Assembly


Composite Lap Trays -Design and ManufactureDesigner: GeoffCase

Client Coordinators: Gale Noble SandersonChildren’s Neuromuscular Program@ Kaylene and Danelle

Supervising Profksors: Kathleen L. KittoManufkcturing Engineering Technology


INTRODUCTIONMost wheelchair manufacturers do not offer any typeof work surfaces (lap trays) or similar accessories de-signed to be attached to a specific wheelchair. Foranything more than a basic flat table, trays are eitherhomemade or custom one-offs designed and built bymedical supply retailers. Commercially available laptrays are constructed of wood, acrylic, polystyrene,polycarbonate or fiberglass. These simple flat traysattach to the wheelchair with a series of Velcro strapsand D-rings. Mounting locations and hardware sup-plies are provided by medical supply retailers.

The material of choice for most of these type of laptrays is either plywood with Formica tops or l/4”acrylic plastic, primarily because these materials canbe cut and drilled using the basic woodworking

power tools; drill press, table saw, and router. Al-though the custom and homemade devices serve theirpurpose, most do not have the finish or durabilitythat would be found in a product designed andmanufactured for that specific purpose. The custom-made acrylic tops usually fail when a crack initiatesfrom holes drilled for mounting hardware when aheavy load is placed near the edge of the workingsurface. The purpose of this project is to examine analternative design that takes advantage of modern“high tech” manufacturing techniques and materialsto produce a quality lap tray product suited for awide range of installations and applications includingthe location and attachment of: communication de-vices or computer keyboards and arm restraints orother devices designed to position the hand and fore-arm.

Figure 18.5. Composite Lap Tray.


SUMMARY OF IMPACTThis project is designed to examine alternatives tocurrent lap tray products to improve quality, durabil-ity, and functionality at a comparable cost. Workingwith the staff of the Children’s Neuromuscular Pro-gram at St. Joseph Hospital, the prototypes are de-signed for use by two different patients to test thevarious design aspects. The basic design criteria are:must be easily installed, secured and removed whennot in use, must be easily adaptable to allow manu-facture to fit a variety of commercially availablewheel chairs and patients, restraints must be robustenough to withstand approximately 40 lbs. force, armrestraints must be easy to adjust and release, and en-sure that no damage or bruising will occur to joints,tissues, etc. during extension/contraction episodes.

TECHNICAL DESCRIPTIONThe two prototype lap trays are constructed of epoxyfiberglass/honeycomb core composite. The core ma-terial can be ordered in various thicknesses and pan-els constructed by laying the fiberglass “prepreg”over the core. In this case, the material for the laptrays is a cut from a pre-made 12’ x 4’ x 0.65” panel,designed to be used as interior flooring in commercialaircraft. The panel is unable to pass QA standards foruse in aircraft and is donated to this project. The topsurfaces of the lap trays are finished with Formicalaminate to provide a smooth surface for patient com-fort. The core of the material is sealed along the outeredges. The outer edges are sealed using an extruded

vinyl “glued” in place with epoxy resin after the corematerial had been cut back from the edge of the skinsapproximately l/4”. Cutouts are also sealed with ep-oxy resin using a similar technique. The slot cutoutsthrough the lap tray are made slightly larger than fi-nal size using a hand router. The core and back skinof the composite are removed an additional l/2-incharound the slots. The slot is taped over and the cavityfilled from the back. After the resin cured, the slotsare again milled in the resin plug to the desired finalsize. If the location for these slots had been deter-mined before the Formica is applied, the large area ofthe resin plug could have been hidden under the toplaminate. The top laminate is attached early in theprocess to improve the appearance of the lap tray be-cause the prototypes are trial-fitted several timesduring the construction in response to changes madeby therapists. The special work surfaces are designedto hold specific communication devices such as com-puter keyboards. The ability to use threaded potableinserts (100 pounds pullout) give these composite laptrays and special work surfaces an advantage overpolycarbonate or acrylic polymer lap trays and hold-ers. The composite lap tray cannot compete directlywith current commercial fiberglass, polymer or press-board lap trays solely on a unit cost basis. However,when considering weight, durability and appearance,the composite lap tray proves to be a better product.For this project, the cost of the 0.65” panel is deter-mined to be $6.25 /sq. ft. which is comparable to thatof polymers currently being used. Total cost for eachtray is $260.

Figure 18.6. Constructing Lap Tray.


Intellifector - Intelligent End EffectorDesigner: Dan Davidson

Client Coordinators: Dorothy BanelleWestern Washington University DSS

Supervising Prqfksor: Kathleen L. KittoManykturing Engineering Technology


INTRODUCTIONAlthough robots are usually used in manufacturingor assembly operations, robots can be used in resis-tance type physical therapy sessions. The robot pro-vides the push or pull back to the person for whomphysical therapy is an essential ingredient in their re-covery. Unfortunately, this type of physical therapyis tedious and requires the use of highly trained spe-cialists. Robots can be used to free up the trainedtherapist for some of the session time if the robot hassome sort of tactile (touch or force sensing) capability.

SUMMARY OF IMPACTTraditional tactile end effecters for robots are usuallyvery expensive and have more resolution than is nec-essary for physical therapy applications. The goal ofthis project is to build a simple-cost effective end ef-fector for a commercial (Adept Technology) SCARArobot that is capable of providing the tactile sensingnecessary for physical therapy applications.

Figure 18.7. Intelligent End Effector Grasping a Potato Chip.

TECHNICAL DESCRITPTIONIn order to achieve simple and predictable controlwith electronic input, an electric motor is chosen formovement of the fingers. Pneumatic control couldalso be used for the rotation of the finger assemblysince it rotates 90” between stops. Translation move-ment of the fingers is desirable so that the finger angledoes not change when the fingers open to differentwidths. A lead screw is chosen because it reducedmechanical complexity for the system. The handmust very wide to accommodate the range of motionnecessary (almost 6.5 inches). There are no bearingsurfaces for the lead screw. The majority of the partsare milled using Computer Numerically Controlled(CNC) machining techniques. The channel, in whichthe fingers slide, is manually machined from squaretubing

Analysis of the hand was completed with finite ele-ment analysis of the fingers. This is done to find re-action forces, amount of component deflections andthe material stresses. The stress at the base of the fin-gers is about 9,000 psi, with a load of 10 lbs. at thefingertips. This is a strain of about 900 microstrains.With a deflection of about 10 thousandths of an inchunder a 10 lb. load, substantial overshoot is possibleafter the desired “grip” is achieved. However, eachfinger deflects at the lead screw bends, resulting inadditional deflection. A cushion is be added to thefingertips to reduce the overshoot effect.

The electronics for hand control are straightforward.The electronics control is divided into four sections:power supply, ADEPT communication, and straingauge amplification and signal comparison. Figure18.8 shows the strain gauge amplification circuit.


The power supply converts the 120 VAC to about 40VAC. The input is then rectified and filtered. Thecenter tap is tied to ground to provide +20 and -20VDC. Three voltage regulators provide +12, -12 and+3 VDC. The +5 VDC to drive the logic is providedby the Adept robot. The ground is referenced toADEPT ground. The Adept’s binary output is runthrough data latches which simplify the hand’s con-trols considerably because the data does not have tobe read and stored by the hand. The data is run into adigital to analog converter that generates a referencevoltage used as a comparison point for the straingauge output. Pull up resistors are used at the inputof the converter as the Adept’s output states are“low” and “off.” The least significant bit of theAdept’s output switches a relay which closes or opensthe hand. The strain gauge signal is amplified by useof a Wheatstone bridge and an instrument on ampli-fier package. Since 120-ohm resistors of the toleranceneeded are not common, dummy gauges are used tocomplete the bridge. Since the dummy gauges are in-side of the hand’s control box, temperature compen-sation is not provided. The comparator circuit simplytakes the reference voltage supplied by the ADEPT(through the D / A converter) and compares the out-put of the strain gauge. If the output of the straingauge exceeds this reference voltage, the motor sup-ply voltage is cut off by a transistor.

A cost effective, intelligent end effector for physicaltherapy sessions was built for the Adept TechnologySCARA robot at Western Washington University.The total cost for the end effector and electronic con-trols is $522. Intelligent end effecters could easily beused to free up time for and reduce repetition and te-dium for highly trained specialists in physical ther-apy.

Strain Gauge Amplification +12vDc

I 28

’ -#

r\, zeroindicator

2 6 27 +

-12vDc15

12 strain

107

r-

wwoutput11

2g 3 2 1 9 8 6

Figure 18.8. Strain Gauge Amplification Circuit.


Portable Muscle Strength Measurement SystemDesigners: Mike Beirne, Geoff Case

Client Coordinators: Tom GradyClient: Bobbi Grady

Supervising Professor: Kathleen L. KittoManlrfacturing Engineering Technology


INTRODUCTIONThe purpose of this project is to develop a portabledevice for use by doctors, patients and physicaltherapists for accurate muscle strength evaluations togauge neurological response, strength and communi-cation ability. The device is designed to use commer-cially available data recording equipment and inter-face with personal computers to provide tracking ofany changes in the condition of the patient. Ideally,the patient obtains an easily quantifiable measure-ment at home with the device. Currently, many MSpatients receive verbal, qualitative assessments oftheir strength, such as “you seem a little weaker onthe left side than the last time we did a therapy ses-sion or assessment”.

As part of a microprocessor and instrumentationclass, the team members developed a device to meas-ure muscular strength using strain gages to measureloading and deflection of a cantilever beam. The sys-tem is designed to be easily portable for use outsideof a doctor’s office and provide a means of recordingthe data for comparison and analysis over a period oftime.

SUMMARY OF IMPACTThe prototype device works very well for a clientwith MS. Although a device with somewhat less ca-pacity and more resolution would be ideal for the cli-ent, the client easily obtains a measurement of theirstrength with the pull device. The total cost of thedevice with measurement instruments is approxi-mately $1500.

TECHNICAL DESCRIPTIONThe device is designed to operate in conjunction witha Texas Instruments’ Calculator-Based Laboratory(CBLB) system. The heart of CBL system is a datacollector designed to link with the TI series of scien-tific calculators such as the TI-82 and TI-85. The data

collector records temperature, voltage and light levelswith the standard probes included in the system.Optional probes available include a pH probe and aforce sensor. Using the optional force sensor, the CBLsystem is a means of providing a method of recordingand calibrating the output from the strain gauges intoa format that is easily usable by client, therapists andmedical personnel.

The basic device for measuring strength is a simplecantilevered beam supported on one end to a baseplate. The base plate is designed to be mounted sothe beam extends either vertically or horizontally fora variety of strength measurement directions. Thefirst step in determining beam length and material isto use Finite Element Analysis (FEA) software tomodel defection and strain to ensure these values didnot exceed the limits that could be used with standardstrain gauges. Figure 18.9 shows the result usingANSYS 5.0a software of a 10 lb. load applied the endof an 8”, l/8” wall square stock aluminum bar.

After determining the size of the beam from the FEAanalysis, the appropriately sized bar stock is weldedto the base plate and the strain gauges are mounted tothe beam. The gauges are mounted approximately 1”from the base, at the point the FEA indicated thehighest strain. The original intention is to modify theCBL force sensor for use with the cantilever beam.The CBL sensor is unusable because the sensor has alimit of only 20 N (4.49 lbs.). This is too small a limitfor a projected force range of 10 - 100 lbs. Fortunately,the amplifier and the strain gauges are provided in akit produced by Vernier Software (the manufacturerof the TI force sensor). The kit provided included theappropriate strain gauges and all the electronic com-ponents for a regulated 3.96 VDC power supply andinstrumentation amplifier. Using FAE S6 straingauges in a Wheatstone bridge, the amplifier uses 3op-amps for two stages of amplification.


The strain gauge amplifier and cantilever beam pro-vide a voltage output proportional to the amount offorce exerted on the beam. The calibration of voltageoutput to force and the recording of the value are alsocomplete. One of the primary portability problems issolved by developing the software program for the

TI-85 calculator (which serves as the controller formeasurement and recording). Users should be care-ful to use the TI 82 or TI 85 calculators that aremarked with the CBL logo. Earlier models of calcu-lators will require software modifications.

Figure 18.9. FEA Analysis of MeasurementBeam.


AVCD - Audio Visual Communication DeviceDesigner: Mike Luuinger

Client Coordinators: Todd MortonChildren‘s Neuromuscular Program

Supervising Prqfkssor: Kathleen L. KittoMan$izcturing Engineering Technology


INTRODUCTIONThe Audio Visual Communication Device (AVCD) isa device that speaks and displays ten different mes-sages. This device aids the communication of non-verbal individuals. The device is designed for simpleplay operations with the push of a single easy toreach button. The messages are all created by the userand set to his or her own personal needs, and with thekeyboard connected, they can all be re-recorded andedited easily in a menu driven environment. TheAVCD contains a total of 40 seconds of recordablespeech, dividable into 10 messages at 6, 4, 2, and 1second time lengths, as determined by the user. Thedisplay is capable of printing 80 standard ASCII char-acters for each message. Figure 18.10 shows the pro-totype of the device.

Figure 18.10. Prototype Audio Visual Com-munication Device.

SUMMARY OF IMPACTDesign requirements includes: battery operation,hand-held (portable), easy to operate, programmable,user friendly, display capabilities and speaking capa-bilities. Surface mount components solve the size andpower consumption problems. The user interfacecontains ten message buttons, and without the key-board connected, the push plays a message and dis-

plays that corresponding message (then, powerdown, to save energy). The main PC board is roughly3 5/B “x 6 3/B” and sits under the user interface (mes-sage button board). The user interface button board is3 5/B” x 5 l/2”. The keyboard has its own separateenclosure with a connector cable (in a XY matrix) tointerface it with the main PC board. The keyboard en-closure is 5 l/2” X 2 l/2” X 1”.

TECHNICAL DESCRIPTIONWith the keyboard connected, the device is in theEDIT / OPTIONS mode, the user selects to:

1. Record a message - the user is prompted tochoose which message he/she would like to rec-ord (push a message button, any other will can-cel) - the message number chosen and its prede-termined time length (set in the Options field) aredisplayed. The user is then prompted to pushthat same message key, and if he/she wishes tocancel, to push any other key.

2. Edit a message - The user is prompted to choosewhich message he/she would like to edit, (or ifcoming out of record mode to type new message)and push enter when done. 3. Display messageonly - prompts for which message and sets thatmessage time length to zero. 4. Play messageonly - prompts for which message and then clearsthat area.

Figures 18.11 and 18.12 show the schematics of theAVCD boards. The cost of producing an AVCD isapproximately $1200, although production boardsdecrease the cost to $625. Although the AVCD ismore powerful than AUGIE, the costs outweigh thebenefits. Users find that AUGIE is easier to use, butless flexible. Most users find the display LCD is notneeded.

IChapter 18: Western Washington University 277

Figure 18.11. AVCD Board 1 Schematic.

Figure 18.12. AVCD Board 2 Schematic.


Foot Operated Computer MouseDesigners: Nate Dale

Client Coordinators: Steve DillmanWestern Washington University CAD and ClM Labs

Supervising Prqfessor: Kathleen L. KittoManufkturing Engineering Technology


INTRODUCTIONComputer pointing devices (computer mice) are diffi-cult to operate for individuals with limited hand orarm motor functions. An alternative to using a handto operate the mouse or using a mouth stick to oper-ate keyboard arrow keys is to use a foot to operate acomputer mouse. In a foot-operated computermouse, the arch or ball of the foot is used to move theball of the computer mouse and toes are used to pressthe left and right picking switches. The heel can beused as a third pick key or to lock the other pick keysin place. In this project, a Microsoft ball mouse (usedon laptop computers) is modified into a foot operatedmouse. The ball mouse components are used under athermoformed foot mouse base to produce a func-tional computer-pointing device. The mouse is sim-ply disassembled. The ball shell is simply place in thefoot base and operated with the arch or ball of thefoot. The finger switches are disassembled andmoved to place in the foot mouse base that is directlyunder the operators’ toes. The “big” toe is used forthe left mouse button and any of the other toes can beused for the right mouse button. Additionally, theheel can be used for any button that the clientchooses. In this case, the heel pick button simulatesthe third pick button on the mouse. Figure 18.13shows a photo of the foot operated computer mouse.

SUMMARY OF IMPACTThe foot operated computer mouse produced in thisproject is used in the Engineering Technology De-partment’s Computer Aided Drafting (CAD) lab andComputer Integrated Manufacturing lab as an alter-native pointing device for students with limited hand

or arrn mobility. The device is easy to operate and in-stall. Since the device is really a standard Microsoftball mouse device, driver settings for the computerprograms do not have to be modified. The devicesimply plugs into the standard 9-pin serial port on thecomputer in place of the hand-operated mouse. Thefoot-operated mouse is robust. Smaller “foot print”devices are obtained by simply thermoforming a newpiece of polyethylene sheet in the Plastics EngineeringTechnology lab. The device is easy to understand anduse. The total cost of the device is approximately$150.

TECHNICAL DESCRIPTIONA standard Microsoft ball mouse is disassembled intoits basic components: ball pointing case/shell andthree pick switches. The ball case is left intact. It ispositioned under the arch or ball of the foot. The cli-ent simply rotates the ball of the mouse with his orher foot. The left and right pick switches are movedto under the toe position of the foot mouse base. Theheel is used as a lock or to simulate the third pickbutton on the mouse. The mouse base case is simplya sheet of thermoformed polyethylene in the shape ofa foot. Different clients are accommodated very eas-ily by thermoforming a new base. A polyethylenebottom plate/sheet covers the base and electroniccomponents.

The device is robust and works very well. Users cansimply plug in the new pointing device in the place ofa standard hand operated mouse. Simple polyethyl-ene toe plates cover the heel and toe pick switches. Asimple thermoforming operation produces the plasticcomponents.


Figure 18.13. Foot Operated Computer Mouse.


Pneumatic Umbrella for Wheel ChairsDesigners: Bart Griffith and Howard Ditsworth

Client Coordinators: Bob WiedmeyerWestern Washington University - Ryan Simons

Supervising Prqfkssor: Kathleen L. KittoManufbcturing Engineering Technology


INTRODUCTIONClients who operate wheel chairs to routinely com-mute across campus are often caught in rain or snowstorms as they move from class-to-class. Wheel chairoperators need a convenient way of deploying anumbrella to cover themselves from the weather con-ditions. Self-reliant operators do not always have anassistant with them during their time on campus. Aportable, pneumatic powered umbrella for wheelchairs solves this problem. The client simply movesswitches to deploy the umbrella. The additionalweight of the components is offset by the convenienceand protection offered by the device. Figure 18.14shows the electrical schematic for the assembly. Fig-ure 18.15 shows the mechanical schematic.

SUMMARY OF IMPACTThe client operates the prototype device when com-muting on campus. The total cost of the system isapproximately $320.

TECHNICAL DESCRIPTIONA 32” double acting cylinder is used to push the um-brella up and down. The 12” double acting cylindertilts the umbrella back when collapsing the umbrellaand then forward to cover the operators’ head. Thesolenoids maintain a position on the cylinder once theoperator has made the adjustment. The ideal sole-noid to fit the application is a series 800 MAC 3-waysolenoid with a dead center. The swivel is a plastictoilet float rocker arm. The umbrella cylinder slidesup through the swivel and is tightened with the plas-tic screw provided. The two cylinders are joined witha 3/4” turnbuckle. Cutting the turnbuckle in half en-ables the two cylinders to be joined as well as swivelin relation to the extension of the lower cylinder.

1” x 1” x l/8” aluminum channel serves as a guide forthe 12” cylinder, preventing any lateral movement ofthe lower end of the umbrella. The aluminum flatstock is used to construct the brackets for holding thecylinders, switches, and solenoids in place on thewheel chair. Brackets hold the parts in place on thewheel chair.

The umbrella assembly is tied into one of the two 12Vbatteries of the wheel chair. The wire from the batterycontains a 7-amp fuse to protect the system. Thecompressor, pressure regulator, flow control valves,and solenoids are attached to the chair using plastictie downs. The opening and closing of the umbrella isrelatively slow, but can be easily changed during in-stallation by adjusting the flow control valves.

Materials/Apparatus: assistance of Ryan Simons andhis battery operated wheel chair, 12” pneumatic dou-ble acting cylinder with a 3/8” ID, 32” pneumaticdouble acting cylinder with a 3/4” ID, 12 V air com-pressor (150 psi), (2) Festo .3-10 bar flow controlvalve, SMC NAW2000 pressure regulator, 3 way me-chanical acrylic, flow control valve with a dead cen-ter, 2 way solenoid flow control valve (MAC 71 lC-12-PI-55 lBA), 12” of 3/8” ID rubber hose, 80” of 11/4” IDrubber hose, “Tote” umbrella, (2) hose clamps, Teflontape, (10) hose fittings, (1) 3/4” turnbuckle, (1) toiletfloat rocker arm, (2) one way electric switch, 7’ of 1l/4” x 1 l/2” aluminum flat stock, 14” of 1” x 1” x 1l/B” aluminum channel, (2) 1 l/2” x 1” bolts with flatand lock washers, and nuts, (7) 3 3/16” x 3 l/4”screws with flat and lock washers, and nuts, and (2)l/8” x 1 ” screw with lock nut.


ELECTRICAL SCHEMATIC

Swi tch S w i t c hf o r f o r

Compressor Solenoid

I I

Figure 18.14. Electrical Schematic for Pneumatic Pow-ered Umbrella.

hessure Regulator

Figure 18.15. Mechanical Schematic for Pneumatic Um-brella.


Incredible Reading Machine Assembly: IRMA I andIRMA II

Designers: Bill Connelly, Steve Carter, B yan Phillips and Brian TrainiClient Coordinators: Kathleen L. Kitto

Whatcom County Library SystemSupervising Prqfksor: Kathleen L. KittoManzg%cturing Engineering Technology


INTRODUCTIONAll students need encouragement or incentives insummer reading programs. Differently-abled stu-dents are no different from other students in this re-spect. The Whatcom County Library program spon-sors a summer reading program for all county librar-ies each summer. This successful program relies oninnovative incentives to keep all students interestedin reading all summer long. IRMA, the IncredibleReading Machine Assembly, was designed and pro-duced by students in the machine design class atWestern Washington University as a device to rewarddifferently-abled students (and all students/adults)for reading a book. In fact, the class constructed twoIRMA devices, IRMA I and IRMA II. They wereplaced in the Femdale and Lynden Libraries in the1995 summer reading program.

Figure 18.16 shows the IRMA I device. Students in-sert a ball bearing in the shoulder of the device to ac-tivate the series of rewards. Each student receives aball bearing to activate the device after reading abook. Once the device is activated, a series of lights,toys and paths delight the operator in a variety ofways. The ball finally falls into a stainless steel sinkand rolls and rolls and rolls its way to a holding con-tainer.

SUMMARY OF IMPACTThe two IRMA devices were enthusiastically receivedat the two country libraries. In fact, other librarieswould have like the devices. The total cost of eachdevice is approximately $750. Although the deviceswere originally designed for differently-abled chil-dren, the libraries found them to be useful incentivesfor all readers - including adults. In fact, the adultsare fascinated by the design and construction as wellas the reward system.

Figure 18.16. IRMA I.

TECHNICAL DESCRIPTIONSteel angle iron welded together is used for the IRMAframes. Rivets are used to hold the metal travel pathsto the iron frame. Acrylic panels encase the IRMA as-sembly. Monitor cases are used as heads for the as-semblies. Flashing strobe lights are used for theIRMA ears. Holiday light provide the flashing IRMA


faces. Clear vinyl tubing provides the path for theball bearing to enter the IRMA device. A funnelguides the ball during its early travel path. Switcheson the metal travel rails start toys to spin, flash orlight up during the ball descent. The ball drops into a

stainless steel bowl at the base of IRMA. The ballstays in the bowl for several minutes before it finallydrops into a holder at the base. Figure 18.17 showsIRMA II being loaded for delivery.

Figure 18.17. Delivery Run for IRMA II.


Pneumatic Interior Automatic Door OpenerDesigners: Gavin Campbell and Leslie Wright

Client Coordinators: Bob WiedmeyerWestern Washington University

Supervising Professor: Kathleen L. KittoMantrfacturing Engineering Technology


INTRODUCTIONThis project uses a pneumatic system (Figure 18.18) toautomatically open and close an inside door operatedby differently-abled clients. The objective of the proj-ect is to change the original door mechanism by hav-ing a pneumatic cylinder system that opens andcloses the door automatically without obstructing theupper section of the door entrance. It is operated by a1 and l/16-inch cylinder with a 8 inch stroke. Unlikea 2-inch cylinder design, this pneumatic cylinder isnot as bulky and does not require as much space. The1 and l/16-inch cylinder is used because its forceoutput best matched the calculated force required toopen the door.

SUMMARY OF IMPACTThe pneumatic automatic interior door opener is aneconomic alternative to commercially available sys-tems. Clients can not easily afford commercial unitscosting $3000 - $5000 per door. Although a pneu-matic system is somewhat more prone to noise an-noyance problems, it is much less expensive. The en-tire set-up for the first interior door is approximately$580. Each additional door could be added to thesystem for as little as $300. The system is easy tomaintain in that all components are obtained from lo-cal stores. Replacement relays are available for RadioShack stores. The noise of the system can be reducedif the air compressor is locked in an attic or preferablyin a room in the garage. The room storing the aircompressor could easily be soundproofed too. Thecompressor only turns on to fill the storage tank.

Figure 18.18. Pneumatic Interior Door Opener.


TECHNICAL DESCRIPTIONRequirements: use as much of the existing hardwareas possible to reduce cost, linkage to be on the insideof the door, door should sweep 93” for easy passagepast door handle, door sweep should be slow andcontrolled, system should be activated by a remotecontrol unit.

The design used for the cylinder has the end of therod connected to a swivel bracket on the inside face ofthe door, eliminating the problem caused by the 2inch cylinder of blocking the upper section of thedoor frame. This also has the advantage of eliminat-ing the swivel arm from the system. The design is notnoticed when the door is opened and closed. Theperson using the door uses a remote to open the door.As the door opens, the rod of the cylinder pushes thedoor open, leaving the cylinder and rod to swivelalongside the door. Once the person has enteredthrough the door passage, the remote is used to closethe door. The pneumatic cylinder then begins to re-tract all the way until the door closes. A safety devicelike a small power pack gives a person an opportu-nity to either open the door to escape or prevent thedoor from unlocking.

Materials List: 316-DXJ? Bimba cylinder with 6”stroke, OCFQP44 Bimba valve, l/4” clear plastic tube,l/4” tube tee, l/4” NE’T male to 3/16 tube fitting, so-

lenoid door striker: fail safe (open when power is off),l/4” NPT female tee, O-125 psi l/4” NPT male pres-sure gauge, solenoid air valves, 8 set delay relay, 110VAC 3 pole relay, 110 V to 24 V AC transformer, 24VAC to 24 VDC rectifier, Black & Decker Air com-pressor, Midwest Products air tank - 2 cubic feet ca-pacity with safety valve, l/8 x 3” 1020 mild steel bandstock, 3/8 UNC x 11/2” grade 5 bolts, 3/8 UNC nuts,and l/4” x 1” lag bolts. System Parameters: Compres-sor: llOV, 25 psi output, Cylinder: Bore=2”, Rod=0.62”Stroke=6”, Force to close the door (extending): Force =78 lbs., Force to open the door (retracting): Force = 48lbs.

Modifications: squared the door hinge and frame,moved moldings to free door movement, and re-moved a spring and filed the striker assembly to en-hance the latch release action. Recommendations: abackup power supply should be installed with 12-hour operation capability as a safety measure. Thissystem allows a person to easily exit the building incase of a power failure. A loo-psi compressor andtank increases the cycles of the door without runningthe pump. A higher pressure in the tank allows for abackup power system that only supplies power to thesolenoids. A button on the wall on the inside allows aperson to open the door in case they do not have theremote. A thermoformed plastic cover for the cylin-der assembly is more visually appealing.

DOOrSolenoid24VAC

120 to24VACtransformer

Figure 18.19.Door Opener.

Pneumatic Schematic Diagram for Interior


New Sip and Puff SwitchDesigners: May Ann Hanson and Ron Mechlinski

Client Coordinators: Gale Nobel SandersonChildren’s Neuromuscular Program

Supervising Professors: Kathleen L,. KittoMantcJacturing Engineering Technology


INTRODUCTIONStudents in the robotics and automation class pro-duced switches used in therapy sessions that are con-trolled by a sip or a puff, rather than a mechanicalpush. These switches are needed for individuals whodo not have the motor skills to reliably use a manualor mechanical switch. The circuit uses a pressuretransducer for control. Students in the class startedwith a concept and produced 12 of the switchingboxes. A photo of one of the therapy sessions is givenin Figure 18.20.

SUMMARY OF IMPACTThe switches that have been produced are routinelyin use at the Children’s Neuromuscular Program inBellingham, Washington. The switches are also usedextensively in the Whatcom County school system.Each switch costs about $120 to produce. The maincost of each circuit is the pressure transducer. Pro-duction quantities of the pressure transducers couldreduce the cost to approximately $80 per switch.

TECHNICAL DESCRIPTIONThe current draw for the circuit is approximately 3.6milliamps and is 96% efficient. It is powered by a 9-volt battery that provides power for the switchingwhen needed. Differential voltage is obtained fromthe 9-volt source through the use of a switched ca-pacitor voltage inverter. Low power consumption isobtained by using low power components. The maininformation circuit is a SenSymS SX-15 pressuretransducer. A differential signal is fed into a differ-ential amplifier. The usable gain is approximately300. The signal is then fed to comparators. Resistorsare used to adjust the sip and puff outputs. Transis-tors provide open collector outputs. The power sup-ply circuit provides three functions. The power sup-

Figure 18.20. Therapy Sessions at the Chil-dren’s Neuromuscular Program.

ply circuit also turns the circuit on and off. The deviceis housed in a polyethylene box with milled slots toaccommodate the 9-volt batter changes, the sip andpuff tube, and the sip and puff adjustments. Finally,the lid for the box is ultrasonically welded into place.A photo of the switches in production is given in Fig-ure 18.21.

Figure 18.21. Switches in Production in the Robotics Lab.

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CHAPTER 18 WESTERN WASHINGTON UNIVERSITYnsf-pad.bme.uconn.edu/1995/chapter_18.pdf · the completed AUGIE out of the work cell. ... AUGie Flow Chart ... Western Washington University