P14006 Bath Tub Lift Phase III Review. Amos Baptiste Jeremy Czeczulin Andrew Hughes Richard Prilenski

Transcription

1 P14006 Bath Tub Lift Phase III Review Amos Baptiste Jeremy Czeczulin Andrew Hughes Richard Prilenski

2 Introductions Name Amos Baptiste Jeremy Czeczulin Andrew Hughes Richard Prilenski Major/Role Industrial & Systems Engineer/Team Leader Mechanical Engineer Mechanical Engineer Mechanical Engineer

3 Agenda Phase II Overview Problem Definition Customer & Engineering Requirements Action Items Benchmarking Concept Selection Design Schematics Electrical & Mechanical Architecture Von Mises Stress Analysis, Displacement, and Factor of Safety Ergonomics Bill of Materials Project Plan (Week 9-12) Team Assessment

4 Problem Statement Bathtub lift a device that provides assistance to an individual with physical disabilities, including limited balance, coordination, or mobility Can reduce the difficulties of raising and/or lowering an individual into the tub by utilizing a powered seat and a simple control module As population grows the number of aged individuals will greatly increase making demand for assist devices increase Project motivation Theresa Loce Improve the current design Current device does not meet her needs Powered lift that is sturdy, comfortable, easy to use/clean, makes minimal noise, and takes into account physical limitations of user Ultimate goal user maintains autonomy and privacy

5 Deliverables Effectively assist the user for bathing purposes Device is easy to access from starting position Minimized operating time Provide a comfortable and supportive seating area Accessible to 10 th -70 th percentile for both genders, regardless of age Reasonably lightweight and portable, able to be transported

6 Current and Desired State Unstable Current Out of production Damaged Difficult access Obstructions prevent full use Desired Easy use Easy access Portable Lightweight

7 Stakeholder(s) Primary Customer: Theresa Loce Contact: Secondary Customer (s): Wheel chair users/handicap public & Elizabeth DeBartalo, Hospitals (RGH), Nursing Homes, suppliers/vendors, & individuals recovering from knee surgeries. Contact: Faculty Guide: Art North Contact: Sponsor (financial support): RIT & Theresa Loce

8 Benchmarking Company Bathmaster Sonaris Bellavita Orca Portable Water Power P14006 Type Battery Battery Battery Hydraulic Battery Number of Lifts 8 to 10 N/A 12 Infinite 12-Oct Time to charge 3 hours N/A 6 hours 0 hours <= 4 hours Weight Capacity 308 lbs 300 lbs 400 lbs 200 lbs >=150 Weight of device lbs 20.5 lbs 35 lbs 19 lbs lbs Arm rest No No No Yes Yes Portable Yes Yes Yes Yes Yes Recline angle 40 degrees 50 degrees 0 degrees 0 degrees degrees Rotate angle 0 degrees 0 degrees 0 degrees 360 degrees >=180 degrees Lifting Height 3"-18" 2.3"-18.8" 17" 2"-21" TBD Back rest dimensions 24" x 14" 25.1" H x12.5"-14.1"w 26" x 27" 15" x 15" >= TBD 18 Seat dimensions 20" x 15"; 27" with flaps 22.4"L x 12.7"W;27.5" with flaps 14.75"W x 19"D N/A 25 TBD x x 15

9 Action Items from Wk 6-9 ID Action Items Owner Status Notes 1 Create drawing from 3D models of bathroom and devices having multiple designs Andrew H. Completed 2 Use ANSYS or other finite element analysis program to test 3D models Andrew H. Completed Was completed in Inventor instead of ANSYS 3 Create ergonomics drawings based on engineering/customer requirements Amos B. Completed Met with Dr. Marshall for review 4 Create a budget and propose it to Art based on bill of materials Amos B. Completed 5 Refine functional decomposition Team Completed Highlighted the function to focus on 6 Plan or conduct a design of experiment for the bath tub lift Amos B. In progress Consider purchasing actuator 7 Create a Bill of Materials Richard P. Completed Rough draft and may be changed overtime 8 Conduct stress analysis on CAD drawings Richard P. Completed 9 Calculate the power necessary to power Jeremy C. Completed Met with Dr. West for review and EE's 10 Update and narrow down concept drawings of project (hand-drawn) Jeremy C. Completed 11 Specify the requirements of parts of the device (battery voltage, steel rating, etc.) Jeremy C. Completed Met with Dr. Boedo 12 Relearn the basics of Creo Parametric; if needed, learn Autodesk Inventor Jeremy C. In progress May not be needed with the usage of Inventor 13 Make any necessary changes to existing documents or pages Team In progress Need to update documents on Edge

10 Electrical vs Hydraulic Design Pro s Easier use (automated) More use scenarios Con s More complicated design Technical limitations Pro s Simpler design Potentially lighter Con s Dependent on water source Limit to power ability Requires more work from user In the end, the battery design fulfills requirements in a more efficient manner

11 Updated Customer Requirements

12 Updated Engineering Requirements

13 Updated Engineering Matrix

14 System Functional Decomposition

15 Initial Single Pillar Design

16 Single Pillar Design

17 Scissor Lift Design

18 Full Battery Design for Both Cases Sub function Solutions Raise Device Water Power Battery Power Inflation Power Remote Control Magnetic Repulsion Chair Crane 2 Transfer Device Getting items for support (trapeze handle) Use of crutches Automation to lift user to the device Personal assistant to help user to device Incorporate user's assist device 3 Assist Legs Personal Assistant to help legs be secured Water power Battery power (platform slides out) Remote control Reclining Platform 4 Rotate/Slide Device Manually Water power Battery power Personal assistant Spring loaded Remote Control 5 Lower Device Water Power Battery Power Inflation Under chair Remote Control Magnetic Repulsion Chair Crane 6 Turn on Water to fill tub Manually turn knob Personal Assistant Remote Control Relocate knobs

19 Concept Selection Scissor Design Pillar Design Criteria 1 Raise Device Transfer Device S S 3 Assist Legs S S 4 Rotate/Slide Device S S 5 Lower Device Turn on Water to Fill Tub S S 7 Affordable Fits Time Constraints Safety Light Weight Portable Durability

20 Pro s & Con s of the Lift Designs Pillar Lift Pro s Lightweight Simpler design Con s Some features may be manually operated Weaker mechanically More prone to tipping Lift motor/mechanisms weaker Limited mobility and range of motion Pro s Scissor Lift Stronger mechanics Able to lift more More automation possible More Stable Con s Larger -> heavier More costly Greater risk of electrical injury Ultimately, the scissor lift is able to better satisfy project needs

21 Pillar Lift CAD Design

22 Scissor Lift CAD Design *

23 Bathroom

24 Electrical Architecture 220V 60 A AC/DC Converter Battery 12/24 V Acutator Moving Parts Controller

25 Mechanical Architecture

26 Power Calculations

27 Extending Arm Calculations Stress ksi Deflection in

28 Scissor Lift Calculations Stress 3.92 ksi Deflection in

29 Pillar Lift Calculations Stress 1.49 ksi Deflection in

30 Stress Analysis for Scissor Lift Figure (1) Von Mises Stress Note: ksi value was limited to 6 ksi to show stress colors in support area. Max stress value marked was 4.8 ksi.

31 Scissor Lift Displacement Figure (2) - Displacement Note: Figure 2 shows the maximum displacement in inches of the support frame. Max value marked was in.

32 Scissor Lift Modified Disp. Figure (3) Displacement Limit Figure 3 shows a limit on displacement to farther show the dispersion of displacement on the scissor frame. Max value was in.

33 Stress Analysis for Extending Arm Figure (4) Von Mises Stress Analysis It is noted that the stress range in the vertical pillar area ranges from ksi. The acceptable stress value for stainless steel is ksi.

34 Extending Arm Displacement Figure (5) Displacement As suspected, the largest displacement values are shown at the edge of the horizontal pillar. The value was measured to be in.

35 Extending Arm F.O.S. Figure (6) Factor of Safety In the medical field, most companies try to aim for a F.O.S. range of 2-4. From that assumption, we will follow that guideline when it comes to the stress analysis of our frame for the bathtub lift. The noted F.O.S. range on the vertical pillar was from 3-7.

36 Ergonomics Important factors to consider: Intended users can fit the device Lumbar support Arm rest height and length Leg clearance ** All measurements are based on ANSUR Database

37 Bill of Materials Chair (Seating Material) Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive? 1 Fiberglass No 2 Gel coated Fiber Glass No 3 Acryllic No 4 5 Chair (Frame) Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive? 1 Carbon fiber No 2 Aluminum No Base (excluding steel fixture for extendable pillar and sunction cups) Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive? 1 Fiberglass No 2 Carbon Fiber No Carbon Alloy Steel (Annealed) No 4 Polyurethane Alloy Extendable Pillar (Raises/Lowers Chair) Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive? 1 A36 Steel Yes Carbon Alloy Steel (Annealed) No 3 Stainless Steel No 4 5 Arm Rest Extendable Arm Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive? 1 Gel Coated Fiber Glass No Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive? 1 A36 Steel Yes Carbon Alloy Steel (Annealed) No 3 Stainless Steel No 4 5

38 Bill of Materials Material Cost Stainless Steel (Beam) $ Stainless Steel (Outside Channel) $ Battery with Charger $ Stainless Steel (for legs/lift) $ Suction Cups (4x) $ Aluminum Pipe $ Gel Coated Fiber Glass Gel Coat $ Fiber Glass $ Mold $ Control Module & Electrical Wiring $ Actuator $ Total $ 1, Total with 30% increase $ 1,998.10

39 Power Sources Electrical Actuator vs. Servo Motor Upon review, the electric actuator would be a perfect fit in assisting with the raising and lowering of the chair frame. Several companies were contacted for more advanced specs of the actuators and the main issue was that they are not waterproof. Therefore 2 scenarios rise up, the first is to do further research on alternative methods and the second is to design a waterproof housing for the actuator (that would take up a significant amount of time).

40 Risk Assessment 1 Risk Item Cause Effect Likelihood Severity Importance Actions to Minimize Owner No adding arm rails. Combination of material, water and Implement a safety User injury due to Minor to severe injury to the human skin not device and use high Team falling/slipping off device customer/user having enough friction materials friction causing user to slip. 2 Electrocution Exposed electrical components User may be electrocuted by direct contact with device or through water Design electrical components to be isolated/sealed from rest of device Team 3 Electric power supply inconsistent Charge from battery may not be User may experience longer sufficient to operate operation times or may device when running become trapped in tub low Apply a warning system/visual indicator that the battery is low. Team 4 Device weight capacity Device not able to lift well over the minimum requirement Device fails under heavy loading, trapping and possibly injuring user Through testing device must lift >150 lbs Team 5 Not being able to fulfill requirements of broad user base (height/weight differences) Not conducting an User may be too big or too ergonomics study on small for device. User may get the stature of the injured due to lack of space or users percentile and not being able to reach certain their reach items. Customer dissatisfaction Conducting ergonomic experiments on the target percentile range Amos Measurement errors Have multiple team members measure

41 5 requirements of broad user Risk Assessment base (height/weight differences) the stature of the users percentile and their reach injured due to lack of space or not being able to reach certain items. Customer dissatisfaction experiments on the target percentile range Amos 6 Fixture dimensions Measurement errors of the bath tub and the device. Not considering thickness of materials in specs. Device not able to fit in the tub. Customer not being able to use the device Have multiple team members measure the dimension of the tub and for every step of the process, re-measure to verify meeting constraints Team 7 Safety of user s legs When fixture is lowering it does not allow enough room for legs Minor to sever injury to the customer/users legs Apply a foot rest at the base of the device so the user can place their feet before operating Team 8 Transfer from starting position to the device Unsafe transition from starting position to the device Possible falling injury Option1: Having the device being able to slide out the tub for the user to access. Option 2: Ensure Team that the device can rotate out of the tub and is stable for users that can stand to use as a support.

42 Risk Assessment tub and is stable for users that can stand to use as a support. 9 Not being able to meet deadlines/milestones Not having a well developed project plan and keeping it updated Product delay which may lost customers trust Have daily or weekly updates on assignments and if help is needed Team 10 Going over budget Not keeping track of budget or knowing what the budget is Having to ask for more or falling short on supplies to develop the product Schedule to audit budget every 2 weeks. Team 11 All team members not being able to meet Miscommunication or lack of communication between team members Team members missing meetings or not being active in their roles Communicate with team verbal and text/ when and where will meetings will take place. Amos 12 User hand getting injured in the process of using the seat Exposed folding mechanism and/or seat lowering to quickly Hand chopped off Ensure through the proof of concept the device will not lower quickly or collapse. In addition, make a safe folding mechanism. Team

43 Test Plan Team plans on purchasing a small actuator and rechargeable power source Actuator ~ $20-30 Battery ~ $10 Create a scaled test rig to test design feasibility Conduct worst-case scenario simulations

44 Team s Vision

45 Project Plan for WK ID Action Items Owner Incorporate Ergonomics drawings with CAD 1 designs Amos, Jeremy, & Andrew 2 Refine CAD designs Andrew Design of control module Develop a battery charging system Contact and meet with Theresa Establish proof of concept in all critical areas Develop a test plan for the device Refine Bill of Materials Arrange meetings with faculty to review Detailed Design for all critical areas Purchase actuator Andrew & Jeremy Jeremy & Richard Team Team Richard Richard & Amos Team Team

46 Project Plan for WK 10-12

47 Questions?