Engineering Design and Computing Lecture Notes PDF

ENGINEERING DESIGN AND COMPUTING Engineering Design and Material Selection Lecture 1 — Introduction and Sketching Prof. Dr. Kristina Shea Dr. Tino Stankovic Pr...

ENGINEERING DESIGN AND COMPUTING Engineering Design and Material Selection Lecture 1 — Introduction and Sketching Prof. Dr. Kristina Shea Dr. Tino Stankovic Prof. Dr. Kristina Shea 1  ENGINEERING DESIGN AND COMPUTING Welcome to mechanical engineering! Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 2  ENGINEERING DESIGN AND COMPUTING Engineering Design: Basic Process The Need Phase 1: Phase 2: Phase 3: Phase 4: Phase 5: Phase 0: Planning Concept System-Level Detail Design Testing & Production Development Design Refinement Ramp-Up Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 3  ENGINEERING DESIGN AND COMPUTING Topic Overview: Requirements Sketches Sustainable Design Design Process Ideation Technical Drawings 2D / 3D Representations Prototyping Computer-Assisted Design (CAD) Engineering Design Material Properties Additive Manufacturing Manufacturing Material Selection Ashby Diagrams Working in Small Teams Sustainable Materials Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 4  ENGINEERING DESIGN AND COMPUTING Practice-Oriented Course Addressing MAVT Grand Challenges Health Future mobility Sustainable materials breathe Kyburz Ski workshop Low-cost ventilators Electric vehicles Sustainable skis Concept generation exercise Balloon power car project Material selection exercises Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 5  ENGINEERING DESIGN AND COMPUTING Balloon Powered Car Project Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 6  ENGINEERING DESIGN AND COMPUTING Course Schedule Week/ Topic Case Study Quiz Lecturer Dates 1 Introduction and Sketching 2 Introducing Engineering Design Health Prof. Dr. Kristina Shea 3 Technical Drawing: Projections and Cuts 4 CAD: Introduction and Modeling Operations 5 CAD: Features and Parametric Modeling Future Mobility 6 CAD: Freeform Modeling Dr. Tino Stankovic 7 CAD: Assemblies and Standard Mechanical Parts X (45 min) 8 Technical Drawing: Dimensioning Health 9 Sustainability in Engineering Design 10 Materials and their Properties 11 Manufacturing Processes with Focus on Additive Manufacturing Sustainable Materials Prof. Dr. Kristina Shea 12 Material Selection 13 Review and Q+A X (75 min) Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 7  ENGINEERING DESIGN AND COMPUTING Learning Objectives § Creatively and systematically tackle design tasks, generate and evaluate concepts and select appropriate materials. § Accurately create and read technical drawings and 3D CAD models of mechanical parts and assemblies. § Understand the connections between engineering design, manufacturing (additive) and material selection. § Gain knowledge about the MAVT grand challenges in healthcare, mobility and sustainable materials. § Learn through hands-on, practice-oriented exercises connected to daily life. § Learn teamwork and critical thinking. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 8  ENGINEERING DESIGN AND COMPUTING Course Information § Lecture (1h/week) § Exercises (3h/week) Mon Tue Wed Thu § All content available on Moodle 14:00-15:00 15:00-16:00 Lecture Exercises Exercises § 2 mandatory quizzes during 16:00-17:00 exercises 17:00-18:00 Exercises Exercises § Course fee of 14.- per student 18:00-19:00 § For printed course handouts, 3D printing Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 9  ENGINEERING DESIGN AND COMPUTING Exercises + Quizzes § Hand in excerises to get feedback from tutors. § Mandatory quizzes are held in the regular exercise sessions quiz nr. week dates tested content time number of questions weight 1 7 4.-7.11. Weeks 1-6 45 min 30 37.5 % 2 13 16.-19.12. Weeks 1-12 75 min 50 62.5 % § The quizzes are closed book, i.e. you are not allowed to bring any material. § Participation in course: § After participation in the first quiz, the course will be graded and the second quiz has to be taken. § A maximum of one quiz can be missed and taken at another date for a valid reason, i.e. illness with a doctor’s certificate § There will be a sample quiz on Moodle released in Week 6. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 10  ENGINEERING DESIGN AND COMPUTING Exercises + Quizzes § The quizzes are online (on Moodle) § The quizzes are in English. Dictionaries for English-German, English-French and English-Italian are available if needed. § Quizzes test content of lectures and exercises § Max. 1 point per question, no negative points for wrong answers If you can’t attend a quiz... § Inform us about your absence (email to [email protected]) § Provide documentation for your absence: § Illness: doctor’s certificate § Military service: Marschbefehl § Doctor’s certificate can be sent later Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 11  ENGINEERING DESIGN AND COMPUTING EDAC Team for EDMS Exercise Head Lectures and Moodle Leader Martin Schütz Andreas Walker Exercise Leaders: Marc Wirth Rafaela Louis Maxime Escande Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 12 12  ENGINEERING DESIGN AND COMPUTING Course Relation to Bachelor Study § Main connections: § Mechanics I + II § Machine Design § Innovation Project § Engineering Materials and Production § Focus Project § Various Electives and Focus Courses Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 13  ENGINEERING DESIGN AND COMPUTING Learning Objectives – Lecture 1 § Gain knowledge about engineering design and an engineering design process. § Understand the need for a new mechanical ventilator and the basic design. § Learn fundamentals of sketching. § Learn fundamentals of projections and views. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 14  ENGINEERING DESIGN AND COMPUTING https://www.telegraph.co.uk/global-health/climate-and-people/burying-africas-equipment-graveyards-50m-programme-launched/ Case Study on Health Introduction: A Mechanical Ventilator Need - Most current medical devices:... are too expensive for low-resource settings http://www.mikemiesen.com/tag/medical-device-graveyards/... can break in harsh environments... are difficult to maintain & repair... are designed for well-trained users in Images: high-resource settings Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 15  ENGINEERING DESIGN AND COMPUTING Mechanical Ventilators Help patients to breathe. Are commonly used for transport, trauma, post- surgical care, sepsis. Are needed in many Low- and Middle-Income Countries. 0.14 Ventilators / 100’000 people in Low-Income Countries 1) 8 - 36 Ventilators / 100’000 people in Europe 2) 1) Craig et al., National estimates of critical care capacity in 54 African countries, 2020 2) Our World in Data: Medical ventilators per 100,000 people, accessed 14. Jan. 2022 Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 16  ENGINEERING DESIGN AND COMPUTING Principle of a Mechanical Ventilator § Resuscitator bags are: § commonly used for manual resuscitation § are easily accessible and comparatively cheap § Automatic, cyclic compression of the bag by a mechanical ventilation system § Resuscitator bags connect to standard and already accessible parts § Air pathway already approved for medical use Adobe Stock picture Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 17  ENGINEERING DESIGN AND COMPUTING From a Need to a Product Sketch First Prototype First Concept First Functional and Form Prototype First Integrated Prototype Second Integrated Prototype Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 18  ENGINEERING DESIGN AND COMPUTING It takes an interdisciplinary TEAM to… Dr. Marianne Schmid Daners Dr. med. Adrian Marty... implement safe MEDICAL procedures Dr. Thomas Lumpe Christos Vasileiou... DESIGN for intuitive usability Milena Overhoff... develop robust HARDWARE Prof. Kristina Shea Leonie Korn... integrate reliable CONTROLS Dr. med. Vanessa Moll Prof. Melanie Zeilinger Martin Meier Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 19  ENGINEERING DESIGN AND COMPUTING What is needed to be a good engineer? § A. Raw talent: either you have it or not. § B. Hard work during weekends and nights alone. § C. Anyone can learn to be a good engineer. § D. You need to know everything about the latest technologies. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 20  ENGINEERING DESIGN AND COMPUTING Conveying Ideas Graphically A device for use with an AMBU-bag having a flexible squeeze bag with a curved outer surface, comprising: § one holding region shaped to correspond to a portion of the curved outer surface of the squeeze bag; § a mechanical compression squeezer for cyclically squeezing the bag from its outside and releasing the bag for expansion; § a powered actuator; and, § one region shaped to hold the squeeze bag during squeezing. US Patent 2012/0145151 Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 21  ENGINEERING DESIGN AND COMPUTING Different Representations Sketch 3D model Technical drawing Photorealistic rendering Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 22  ENGINEERING DESIGN AND COMPUTING An Introduction to Sketching § Sketching is a simple idea communication tool (“napkin prototyping”) Sketch of a helicopter by § Often used in concept generation phase Leonardo da Vinci § Common tools: pen, pencil, tablet § Can be learned (like sports or music) Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 23  ENGINEERING DESIGN AND COMPUTING Process from Mental Model to a Sketch 1. Define goals 2. Build mental representation 3. Select representation mode 4. Sketch 5. Validate Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 24  ENGINEERING DESIGN AND COMPUTING Define Goals for Sketches § What do I want to show? § Who is the target audience? § What is the goal? § Concept sketch § Function-oriented sketch § Design sketch § Support sketch Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 25  ENGINEERING DESIGN AND COMPUTING Define Goals for Sketches § What do I want to show? § Who is the target audience? § What is the goal? § Concept sketch § Function-oriented sketch § Design sketch § Support sketch Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 26  ENGINEERING DESIGN AND COMPUTING Define Goals for Sketches § What do I want to show? § Who is the target audience? § What is the goal? § Concept sketch § Function-oriented sketch § Design sketch § Support sketch Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 27  ENGINEERING DESIGN AND COMPUTING Define Goals for Sketches § What do I want to show? § Who is the target audience? § What is the goal? § Concept sketch § Function-oriented sketch § Design sketch § Support sketch Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 28  ENGINEERING DESIGN AND COMPUTING Define Goals for Sketches § What do I want to show? § Who is the target audience? § What is the goal? § Concept sketch § Function-oriented sketch § Design sketch § Support sketch Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 29  ENGINEERING DESIGN AND COMPUTING Projections: What do I want to show? Different projections Different viewpoints Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 30  ENGINEERING DESIGN AND COMPUTING Taxonomy of Projections Planar Geometric Projections Parallel Orthogonal Axonometric Oblique Perspective Isometric Cabinet One-point top front side Two-point 1st Angle and 3rd Angle Dimetric Cavalier (Lecture 3) Trimetric Three-point Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 31  ENGINEERING DESIGN AND COMPUTING Perspective Projection projectors y z x view center projection what viewer sees plane Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 33  ENGINEERING DESIGN AND COMPUTING Sketching One and Two-Point Perspective Projections vanishing points horizon line 1-point 2-point Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 34  ENGINEERING DESIGN AND COMPUTING Parallel Projection parallel projectors y z x view direction what viewer sees projection plane Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 35  ENGINEERING DESIGN AND COMPUTING Parallel vs Perspective Projection § Used in technical drawings § Closer to the eyes’ perception § Elements with equal length are equally § Used in “photorealistic” rendering (design, dimensioned architecture) § Dimensions can be measured on drawing § Elements with equal length can have different dimensions Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 36  ENGINEERING DESIGN AND COMPUTING Orthogonal Projection top parallel projectors front side Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 37  ENGINEERING DESIGN AND COMPUTING Axonometric Projections Isometric projection a:b:c=1:1:1 a = b = 30° Dimetric Projection Most commonly: a:b:c=1:1:1/2 a=42° b=7° Trimetric Projection a:b:c=free 30°≤a≤45° b≤30° Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 38  ENGINEERING DESIGN AND COMPUTING Oblique Projections Cavalier Projection a:b:c=1:1:1 a = 45° b = 0° Cabinet Projection a:b:c=1:1:1/2 a = 45° b = 0° Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 39  ENGINEERING DESIGN AND COMPUTING Circular Shapes in Parallel Projections Circles in isometric projection a:b:c=1:1:1 a=b=30° Circles in cabinet projection a:b:c=1:1:1/2 a=45°b=0° Circles in orthogonal projection Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 40  ENGINEERING DESIGN AND COMPUTING Sketching Circles and Ellipses Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 41  ENGINEERING DESIGN AND COMPUTING Sketching Techniques: Two different approaches § Outline and refine (outside to inside) § Reduce to basic structure and complete (inside to outside) Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 42  ENGINEERING DESIGN AND COMPUTING Outline and Refine Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 43  ENGINEERING DESIGN AND COMPUTING Reduce to Basic Structure and Complete – Bike Frame I Source: Meier, M. (2005) Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 44  ENGINEERING DESIGN AND COMPUTING Reduce to Basic Structure and Complete – Bike Frame II Source: Meier, M. (2005) Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 45  ENGINEERING DESIGN AND COMPUTING Sketching Tips Make cuts Preserve to show what is proportions Use outlines necessary Strap Use Focus on Ear cover annotations Use meshing as an aid important aspects and comments Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 46  ENGINEERING DESIGN AND COMPUTING Examples from Student Work - “Mechanized Latrine Emptying” Team: Bregenzer, Feser, Ramazani, Sartor, Yu Team: Dewan, Dorner, Hurst, Hüssy, and Peng Product Development and Engineering Design (PDED), 3rd year or Master, 2023 Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 48  ENGINEERING DESIGN AND COMPUTING Checklist for Validating Sketches Here are some questions that enable you to check the sketch quality: § Is the object/function sketched clearly? § Is the sketch aligned with the goals set? § Is the sketch technically sound and clean? § Are the proportions and scale correct? § Is the perspective clear? § Are annotations needed to understand the sketch? § Are you satisfied with it? (“Review”) Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 49  ENGINEERING DESIGN AND COMPUTING Validate: Scale and proportion H h b B b~B/2.5 h~H/2.5 Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 50  ENGINEERING DESIGN AND COMPUTING What is the most important aspect when sketching for concept generation? § A. I should only use perspective projections. § B. I need to know what I am trying to convey to create the sketch accordingly. § C. I should omit the details that are not needed to understand the concept. § D. Only pencils are allowed for sketching. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 51  ENGINEERING DESIGN AND COMPUTING Engineering Design and Sketching: Wrap-up Engineering design starts from a need and follows a systematic process. Sketches are an important part of the design process and everyone can learn how to sketch. There are many different types of perspectives that objects can be drawn in and the most suitable must be selected. Sketching techniques can help you with your first sketches. Check your sketch quality with the validation questions. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 52  ENGINEERING DESIGN AND COMPUTING Exercise 1: Sketching and Engineering Design Can you sketch these objects? Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 53  ENGINEERING DESIGN AND COMPUTING Stand up for respect! https://www.youtube.com/watch?v=vViDmLltxwE Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 18.09.24 54 54  ENGINEERING DESIGN AND COMPUTING Where does the joking end? What is mobbing and bullying? § In mobbing or bullying, a person is, for example, systematically targeted, sneered at, deliberately ignored, constantly interrupted, slandered, treated unfairly or threatened, over a long period of time. § Mobbing goes too far! What is sexual harassment? § Sexual harassment includes any behavior that is unwelcome by the recipient; this ranges from crude remarks about appearance, sexist jokes to sexual assault. § Sexual harassment is not flirting! ETH Zurich and D-MAVT do not tolerate disrespectful behavior. We interact with each other in a supportive, fair and constructive manner! Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 55  ENGINEERING DESIGN AND COMPUTING Where can I find help? How do I avoid disrespectful behavior? -> First consider whether my behavior can be hurtful towards others (even unintentionally!). What should I do if my behavior is interpreted as disrespectful? -> Apologize! (“I didn't know I would hurt you with that.”) What do I do when I observe disrespectful behavior? -> Stand up, step in and offer support to the person concerned. Contact and advice services § ETH internal advice and conciliation service respect Contact: +41 44 632 20 38 | [email protected] § More advice services: https://respekt.ethz.ch/en/contact-and-advice-services.html § MAVT Code of Conduct: https://mavt.ethz.ch/the-department/code-of-conduct.html Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 56  ENGINEERING DESIGN AND COMPUTING Ellipses and Circles § Consider the orthogonal projection of the shown object when seen from the top. Which of the statements is correct? § A. The circular shape is shown as a circle. § B. The circular shape is shown as an ellipse. Prof. Dr. Kristina Shea Engineering Design + Computing Laboratory 57  Overview of Key Elements in Engineering Design User Process Organization Product Models Methods Prof. Kristina Shea Engineering Design + Computing Laboratory 4  A Product Development Process Phase 1: Phase 2: Phase 4: Phase 5: Concept System-Level Phase 3: Testing & Production Phase 0: Planning Detail Design Development Design Refinement Ramp-Up Prof. Kristina Shea Engineering Design + Computing Laboratory 5  Phase 1: Concept Development Phase 1: Phase 2: Phase 4: Phase 5: Phase 3: Phase 0: Planning Concept System-Level Testing & Production Detail Design Development Design Refinement Ramp-Up Purpose: Tasks include: Define product requirements Identify lead users Generate promising concepts and Identify competitive products select one for further development Collect user needs and testing Define product requirements Develop alternative design concepts Evaluate the design concepts and select one Build and test concept prototypes Prof. Kristina Shea Engineering Design + Computing Laboratory 6  Product Development – An Interdisciplinary Process Engineers rarely work alone in product development Product development teams include: Need for effective communication: ▪ Engineers of different disciplines ▪ Be aware of discipline specific knowledge ▪ Industrial designers and standards: ▪ Market researchers ▪ ‘Do I express myself clearly?’ ▪ Field experts (e.g. Medicine, ▪ ‘Do I explicitly state requirements Biology, Chemistry,...) instead of assuming them as given?’ ▪ Define system interfaces explicitly ▪ Perspectives and priorities can differ immensely ▪ Communication is the key to get on the same page Prof. Kristina Shea Engineering Design + Computing Laboratory 7  Requirement Definition What are the requirements? Why do we need well-defined requirements? To effectively communicate and define goals, Needs the product is supposed to fulfil priorities, and interfaces for the product Explicit descriptions of the desired form and To capture user expectations in a binding functionality of the product contract To ensure the fitness of the product for its Solution-independent intended use Prof. Kristina Shea Engineering Design + Computing Laboratory 8  Which Device Fits Your Requirements? “I need a charging device...” A B C Prof. Kristina Shea Engineering Design + Computing Laboratory 9  Which Device Fits Your Requirements? “I need a charging device...” “...that can deliver at least 50 W...” Prof. Kristina Shea Engineering Design + Computing Laboratory 10  Which Device Fits Your Requirements? “I need a charging device...” “...that can deliver at least 50 W...” “...through an USB-C interface.” Prof. Kristina Shea Engineering Design + Computing Laboratory 11  Challenges of Understanding User Needs ▪ Not all user needs are obvious or explicitly mentioned by users ▪ Interview techniques are used to find what are called “latent” needs, or non- obvious ones. ▪ Standards, norms and regulatory bodies. Goal: Develop a user understanding that will justify your task definition and target scenario as well as future product specifications. Oakland, John S. Tot al quality managem ent and operati onal excellence: text with cases. Routl edge, 2014. Prof. Kristina Shea Engineering Design + Computing Laboratory 12  Types of User Needs Unfulfilled ▪ Easy for the customer to express ▪ Known to be difficult to address ▪ Generally not fulfilled Explicit Latent ▪ Easy for the user to express ▪ Hard for customers to express ▪ Widely known and understood ▪ Not yet widely understood ▪ Likely to be already fulfilled in ▪ Currently unaddressed existing products Prof. Kristina Shea Engineering Design + Computing Laboratory 13  Product Specifications: Motivation Translate needs into precise targets. Agree on what Resolve trade-offs. constitutes success. Develop confidence that the product will gain significant market share. Prof. Kristina Shea Engineering Design + Computing Laboratory 14  Product Specifications: What are they? ▪ Precise, measurable quantities of “what” the product will do. Improved buildability and compactness ▪ They do NOT say “how” to do it!, i.e. no solutions! ▪ Specifications are as specific as possible – quantitative ▪ Continuously refined over the initial stages of product The ventilator must be smaller than l x w x h development. w w l w l h h h l ht tps:/ /upload. wikimedia. org/wikipedia/ com mons/ 3/31/ Servo_I_V entilat or.jpg Prof. Kristina Shea Engineering Design + Computing Laboratory 16  Product Goal Product Specifications: Bicycle Example Identify User Needs Establish product specifications Generate, Select and Test Product Concepts Adapted from:Ulrich, K. T., Eppinger, S. D., & Yang, M. C. (2008). Product design and development (Vol. 4, pp. 1-3). Boston: Finalized Specifications McGraw-Hill higher education. Prof. Kristina Shea Engineering Design + Computing Laboratory 17  Establishing Product Specifications Translating User Needs ▪ It is necessary to translate user needs to a set of precise, measurable specifications ▪ If these specifications are met, the underlying user needs will be satisfied as well ▪ Based also on competitive benchmarking, norms and regulations ▪ Example user need: Reduce vibration felt in the user’s hands; tests available are: Maximum value from known benchmark test “Monster” – units [g] Minimum descent time on test track – units [s] Adapted from:Ulrich, K. T., Eppinger, S. D., & Yang, M. C. (2008). Product design and development (Vol. 4, pp. 1-3). Boston: McGraw-Hill higher education. Prof. Kristina Shea Engineering Design + Computing Laboratory 18  Establishing Product Specifications Ideal and Marginal Values Example: Bicycle suspension system ▪ Ideal value – best value the team could hope for ▪ Marginal value – value that would just make the product commercially viable ▪ Five ways to define: 1. a ≥ X 2. a ≤ X 3. X ≤ a ≤ Y 4. a = X 5. a = {X; Y; Z} Adapted from:Ulrich, K. T., Eppinger, S. D., & Yang, M. C. (2008). Product design and development (Vol. 4, pp. 1-3). Boston: McGraw-Hill higher education. Prof. Kristina Shea Engineering Design + Computing Laboratory 19  Mechanical Ventilator: Product Goals ▪ Low-cost and high quality ▪ Meets regulatory requirements ▪ Multiple ventilation modes ▪ Improved buildabilty and compactness ▪ Robust ▪ Easy to maintain ▪ Easy to learn and use Prof. Kristina Shea Engineering Design + Computing Laboratory 20  Technical Specifications The breathe ventilator is an emergency and transport ventilator that is built to ventilate critically-ill patients (adult and pediatrics) in any emergency situation. It is specifically designed for low- resourced settings and enables fast and reliant patient treatment through its first-of-its-kind bag- based solution and its ease of use, portability and long battery run-times. Improving emergency care in low-resource settings Technical specifications: Patient range : Pediatrics to adults (from 5 kg) Ventilation modes: CMV-VC, CMV-PC, CPAP, SIMV Dimensions: 35 cm x 36 cm x 32 cm Weight: 6.8 kg Redundancy: Removable integrated resuscitator bag Battery: Internal/external charging, exchangeable, run-time up to 10 hours Quick settings: Ideal body weight of 20 kg, 40 kg, 60 kg, 80 kg Gas supply: Room air (compression via bag on the inside) Low flow oxygen up to 15 L/min (from oxygen concentrator / oxygen bottle or wall outlet) The breathe ventilator is an emergency and transport ventilator that is built to ventilate critically-ill patients (adult and pediatrics) in any emergency situation. It is specifically designed for low- resourced settings and enables fast and reliant patient treatment through its first-of-its-kind bag- based solution and its ease of use, portability and long battery run-times. Prof. Kristina Shea Engineering Design + Computing Laboratory 21  Requirements can be very specific, i.e. to follow a curve Pressure Flow Volume Oxford Textbook of Critical Care (2 ed., April 2016) Prof. Kristina Shea Engineering Design + Computing Laboratory 22  https://breathe.ethz.ch Prof. Kristina Shea Engineering Design + Computing Laboratory 23  Challenges of Requirements – Why Prototyping Is Needed Objectives of paddle design: Use of prototyping to determine the paddle-shape ▪ Maximize compression of the bag ▪ Compatibility with different bag sizes Compression of a soft bag ▪ Relation between paddle profile and performance not intuitive ▪ Difficult to simulate and optimize Prof. Kristina Shea Engineering Design + Computing Laboratory 24  In the exercise you will formulate two requirements for the ventilator and develop four further ones on your own: ▪ Maximize the tidal volume, which is the volume of air delivered for each compression of the resuscitator bag. You must have a range of at least 300–450ml. ▪ The device must be compact since the use case is emergency situations and the transport of patients. Prof. Kristina Shea Engineering Design + Computing Laboratory 25  Which of the requirements for the ventilator gear box are well formulated? (multiple answers possible) ▪ A. The axes should be supported by ISO15 ball bearings with an inner diameter of 10mm. ▪ B. The gear box housing must be made of cast aluminum. ▪ C. The gear box should weigh less than 4kg. ▪ D. The gears must be protected against dust. Prof. Kristina Shea Engineering Design + Computing Laboratory 26  Concept Generation and Selection Design task Concept Solutions Concept Generation Requirements and Selection Prof. Kristina Shea Engineering Design + Computing Laboratory 27  Concept Generation and Selection Design task Concept Solutions Concept Generation Requirements and Selection Prof. Kristina Shea Engineering Design + Computing Laboratory 28  Concept Generation and Selection – A Systematic Approach Concept Development Design task Problem Clarification External Search Internal Search Concept Solutions Requirements Systematic Exploration Reflection Concept Selection Prof. Kristina Shea Engineering Design + Computing Laboratory 29  Concept Generation and Selection – Theory vs. Practice Concept Development Design task Problem Clarification External Search Internal Search Concept Solutions Requirements Systematic Exploration Reflection Concept Selection ▪ Design processes do not strictly move in one direction ▪ Jumps between stages can be useful and necessary ▪ Avoid infinite loops and carefully consider revising a design decision. Prof. Kristina Shea Engineering Design + Computing Laboratory 30  Clarify the Problem – Main Function and Functional Decomposition Central Question The formulation of the main function ▪ Should be solution-independent What is the underlying problem I am trying to solve? ▪ Influences the explored space for concept solutions Main Function energy flows airflow Main Function Create airflow energy air material Critical Subfunction signal energy energy airflow airflow Sub-Functions Accept/store energy Accelerate air Guide airflow air Prof. Kristina Shea Engineering Design + Computing Laboratory 31  External Search – Look for Existing Concepts Search Patents ▪ Determine the State-of-Art ▪ Search published literature Benchmark related products ht tps:/ /comm ons.wikimedi a.org/wiki/ File: Am bu_Bag_valve_mask.jpg ▪ Interview lead users ▪ Consult experts ventilation profile ht tps:/ /upload. wikimedia. org/wikipedia/ com mons/ 3/31/ Servo_I_V entilat or.jpg volume-controlled energy energy airflow airflow airflow Accept/store energy Accelerate air Guide airflow Control airflow air Additional subfunction based on external search Prof. Kristina Shea Engineering Design + Computing Laboratory 32  External Search – Results for the Ventilator Accept/store energy Accelerate air Control airflow Prof. Kristina Shea Engineering Design + Computing Laboratory 33  Internal Search – Development of New Concepts ▪ Concept development is a process that can be learned Creativity Methods ▪ Creativity methods ▪ Support the development process Make analogies ▪ Can help to overcome human bias and fixation Wish and wonder Guidelines 1. Suspend judgement Stimuli 2. Generate a lot of ideas Set quantitative goals 3. Welcome ideas that seem infeasible 4. Make plenty of sketches 5. Build sketch models Prof. Kristina Shea Engineering Design + Computing Laboratory 34  Related Stimuli Hand pumping of bag. Tip: Search for videos on different techniques for ventilating a patient manually. Prof. Kristina Shea Engineering Design + Computing Laboratory 35  Unrelated Stimuli Prof. Kristina Shea Engineering Design + Computing Laboratory 36  Creativity Methods – Brainwriting Brainwriting is a team ideation method similar to brainstorming People generate ideas in a group and pass them around for the others to work on. Often used in the 6-3-5 format: 6 people 3 initial ideas (per person) 5 minutes per round working on the ideas Other formats are possible e.g. 4-3-5 P hoto by f auxels Prof. Kristina Shea Engineering Design + Computing Laboratory 37  Internal Search – Results for the Ventilator Accept/store energy Accelerate air Control airflow Prof. Kristina Shea Engineering Design + Computing Laboratory 38  Explore Systematically – Concept Classification Tree Accept/store energy Electrical Mechanical Pneumatic Thermal ? Benefits 1. Elimination of less promising branches 2. Identification of independent approaches to the problem 3. Exposure of fixation on certain branches 4. Refinement of the problem decomposition for a particular branch Prof. Kristina Shea Engineering Design + Computing Laboratory 39  Explore Systematically – Concept Classification Tree Accept/store energy Electrical Mechanical Pneumatic Thermal Benefits 1. Elimination of less promising branches 2. Identification of independent approaches to the problem 3. Exposure of fixation on certain branches 4. Refinement of the problem decomposition for a particular branch Prof. Kristina Shea Engineering Design + Computing Laboratory 40  Concept Classification Tree – Results for the Ventilator Accept/store energy Accelerate air Control airflow Prof. Kristina Shea Engineering Design + Computing Laboratory 41  Explore Systematically – Concept Combination Table ▪ Combine different partial solutions to solution concepts Subfunction 1 Subfunction 2 Subfunction 3 ▪ Think about the physical and geometric interfaces among Concept 1-1 Concept 2-1 Concept 3-1 partial solutions Concept 1-2 Concept 2-2 Concept 3-2 ▪ Refinement of partial solutions might be needed to derive a solution concept Concept 1-3 Concept 3-3 Concept 3-4 Prof. Kristina Shea Engineering Design + Computing Laboratory 42  Concept Combination Table – Concept Combination A Accept/store energy Accelerate air Control volume flow Prof. Kristina Shea Engineering Design + Computing Laboratory 43  Concept Combination Table – Concept Combination B Accept/store energy Accelerate air Control volume flow Prof. Kristina Shea Engineering Design + Computing Laboratory 44  Based on what you have learned so far: How would you approach the concept generation phase? (multiple answers possible) ▪ A. Focus on known functional principles to ensure the developed concept will work. ▪ B. Develop the most promising concepts to a high level of detail. ▪ C. Generate a variety of concepts without immediately judging them. ▪ D. Utilize creativity and classification methods to fill gaps in the explored solution space. Prof. Kristina Shea Engineering Design + Computing Laboratory 45  Concept Selection – Approaches Concept selection takes place explicitly and implicitly ▪ Explicit: Decision processes, discussion ▪ Implicit: Bias in formulation of requirements and task descriptions, favouring of established solutions, dominance of group members Concept selection methods support a conscious selection P hoto by RODNA E Producti ons process based on explicitly developed criteria. Prof. Kristina Shea Engineering Design + Computing Laboratory 46  Concept Selection Method – Pugh Concept Screening Matrix Example: Reuseable insulin syringe for ▪ Simple and quick concept selection method outpatient injections ▪ Definition of selection criteria ▪ Basic evaluation of the generated concept solutions/variants next to each other (Plus + / Same 0 / Minus -) ▪ Ranking of concepts based on evaluation score ▪ The highest ranking concepts are then selected for further development. Prof. Kristina Shea Engineering Design + Computing Laboratory Source: https://www.novonordisk.com/our-products/pens-and-needles/novopen-4.html 47  What are pitfalls of concept selection methods? (multiple answers possible) ▪ A. Prefer solutions that are already implemented in existing products. ▪ B. Using a selection tool to justify a personal or team favorite. ▪ C. Invest time into the consideration of unrealistic concepts. ▪ D. A decision is made too early. Prof. Kristina Shea Engineering Design + Computing Laboratory 48  Concept Testing and Prototyping User Interviews Prototyping ▪ Present the developed concept to users and ▪ Can be used in different stages of the design evaluate their reaction process ▪ Measure user interest to estimate the potential ▪ For concept development: Build a physical market share version of your concept to evaluate the proposed functional principle and user interaction Photo by Sora Shimazaki Photo by Senne Hoekman Prof. Kristina Shea Engineering Design + Computing Laboratory 49  Mechanical Ventilator: Usability Study ▪ 5 anesthesiologists in Zurich ▪ 3 have experience working in low-income countries ▪ Experience in ICU, shock room, OR and ambulance ▪ Findings: ▪ Easy to use for the first time and felt confident using it. ▪ Easy for participants to teach someone how to use it. ▪ A smaller size would be better for transport and emergency use case. ▪ All participants said that their overall experience with it was either good or very good. Prof. Kristina Shea Engineering Design + Computing Laboratory 50  Concept Generation and Selection – Wrap Up Well-defined requirements guide the design process Concept development can be approached systematically Design methods can help in the concept development process (functional decomposition, creativity methods, selection matrices,...) Prototyping helps to validate concepts, carry out usability studies and identify additional requirements An explicit concept selection process can help to overcome bias and fixation Prof. Kristina Shea Engineering Design + Computing Laboratory 51  Exercise 2: Design and Concept Generation Can you and your colleagues come up with a better design for the ventilator? Prof. Kristina Shea Engineering Design + Computing Laboratory 52  Exercise 2: Design and Concept Generation Tips for Teamwork Tips for a Creative Mood ▪ To reduce potential misunderstanding, it is ▪ A creative mood is sometimes seen as an ability good practice to be as explicit as possible to play with ideas and explore them, with no in your communication. What you say immediate practical purpose. might be heard and perceived differently ▪ Accept all ideas irrespectively of their feasibility. than intended. Use a sketch! Defer judgment to not hinder the creative mood. ▪ Give constructive feedback on both ▪ Explore all ideas fully. See where it takes you! positive and negative aspects: Start by pointing out something good about the ▪ Do not interrupt someone explaining their idea. Try to build on others’ ideas constructively. idea of your colleague. ▪ Treat everyone with the same respect. ▪ Be kind to each other. Prof. Kristina Shea Engineering Design + Computing Laboratory 53  Exclusive for Views technical drawing Parallel projections Orthogonal (or orthographic) projection Isometric projection a:b:c=1:1:1  =  = 30° Dimetric Projection Most commonly: a:b:c=1:1:1/2 =42° =7° Trimetric Projection a:b:c=free 30°≤≤45° ≤30° Prof. Kristina Shea Engineering Design + Computing Laboratory 4  3D Model of a Mechanical Ventilator Prof. Kristina Shea Engineering Design + Computing Laboratory 5  Why Do We Need Technical Drawings? Info that needs to becontained ▪ How can we communicate the details of a complex design? ▪ How can we provide manufacturing instructions? ▪ How can we specify requirements for testing and inspection? ▪ How can we enable maintenance and service over time? Prof. Kristina Shea Engineering Design + Computing Laboratory 6  Use drawing technical Use of Technical Drawings in Product Development Communication Manufacturing Testing and Inspection Maintenance and Service Prof. Kristina Shea Engineering Design + Computing Laboratory 7  Technical Drawings Key Components ▪ Technical drawings store all relevant information relative to a part and assembly ▪ They are a set of rules and common practices for a “universal language” that is language independent (ISO Norms) Complete Unambiguous 4 key Components Readable Consistent National norms: SN = Swiss Norm Prof. Kristina Shea Engineering Design + Computing Laboratory 8  Main Shaft Technical Drawings Main Shaft Prof. Kristina Shea Engineering Design + Computing Laboratory 9  Main Types of Views Orthogonal Projections Detail Views Too so Sections withstood without Prof. Kristina Shea Engineering Design + Computing Laboratory 11  Line Types ▪ Continuous wide line: Visible outlines and edges, lines of reference arrows ▪ Continuous narrow line: Contour edges, hatching ▪ Continuous narrow free-hand line (zigzag line in drawings made in CAD): Break line: Termination of partial or interrupted views (if limit is not a centerline) ▪ Dashed narrow line: Hidden outlines and edges ▪ Long-dashed dotted narrow line: Center lines, lines of symmetry ▪ Long-dashed double-dotted narrow line: Outlines of adjacent parts ▪ Long-dashed dotted narrow line, but wide at ends and at direction changes: Indication of section planes Prof. Kristina Shea Engineering Design + Computing Laboratory 12  Technical Drawing: Process 1. Choose the principal view 2. Choose other required views and cuts 3. Draw the views and cuts 4. Add dimensions (Lecture 8) 5. Verify Prof. Kristina Shea Engineering Design + Computing Laboratory 13  First Example: Cover Plate Prof. Kristina Shea Engineering Design + Computing Laboratory 14  Cover Plate: Which View Should Be The Principal View? A B D O C Prof. Kristina Shea Engineering Design + Computing Laboratory 15  First Angle Projection Method Projectile EU US Ingle perfide Top Principal view 3rd Angle Prof. Kristina Shea Engineering Design + Computing Laboratory 16  First Angle Projection Method Principal view Prof. Kristina Shea Engineering Design + Computing Laboratory 17  Arranging Views: First Angle Projection Method Prof. Kristina Shea Engineering Design + Computing Laboratory 18  Third Angle Projection Method Principal view Plane between Prof. Kristina Shea Engineering Design + Computing Laboratory view Object 19  Arranging Views: Third Angle Projection Method Prof. Kristina Shea Engineering Design + Computing Laboratory 20  Selecting Views: Use The Fewest Views Needed minimize number always of views Prof. Kristina Shea Engineering Design + Computing Laboratory 21  Arranging Projections sich B first angle prine projection