Theory of Technical Systems Basis for a Systematic ...

Ecole de Mines Paris, 1-2 February 2016 The Design Society – Special Interest Group Design Theory

Theory of Technical Systems Basis for a Systematic Engineering Design Process Part 2 – Case Examples W. Ernst Eder Professor Emeritus, Royal Military College of Canada Dr. h.c., University of West Bohemia

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CASE EXAMPLES – illustrate only some aspects of the possible design procedures. – sequence of design documents – supporting framework for understanding the recommended design procedures according to the procedural model – full procedure should be learned, such that the designer can select parts for other applications. – post-hoc reconstructions from the author’s records. – subjective, anecdotal, and cannot be verified. – no attempt was made to create a formal research protocol

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Published Case Examples 1976 [223] – a machine vice, 1980 [238] – a welding positioner. 1982 [233] – a riveting fixture, a milling jig, a powder-coating machine, * a P-V-T-experiment, a hand winding machine for tapes, a tea brewing machine, * a wave-powered bilge pump, * an oil drain valve – the powder coating machine, the tea brewing machine and the bilge pump only loosely followed the systematic method. 2008 [152] – the tea machine (1982) revised to current systematic procedures, re-design of a water valve [122] (first demonstration of re-design), an electro-static smoke gas dust precipitator, with sub-problem ‘rapper for dust removal’ [131] (first demonstration of treatment of sub-problems), 2010 [153] – a trapeze demonstration rig [133], re-design of an automotive oil pump [151], a hospital emergency bed, with sub-problem ‘compensation for the support arrangement’, 2012 – leeboard mounting [138], propeller shaft bearing arrangement [139], 2012 – bow thruster covers [140], wind tunnel balance model support [141], 2013 – ship-to-shore gangway [144], 2014 – life-boat davit [148], with sub-problem. Several cases were designed by the author for the Caravan Stage Barge (http://www.caravanstage.org), which operated since 1995 in Canadian and U.S.A. coastal waters, and in the Mediterranean from 2005 to 2014. 2014 were a Linear Friction Test Equipment [149], NEW re-design of a corkscrew for uncorking wine bottles,

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Case Example 1: Life-boat Davits Founded in 1970, the Caravan Stage Company [78] traveled by large trucks in Canada and the U.S.A. from place to place, entered a community with horse-drawn gipsy-style caravan carriages, pitched a large (24 m diameter) decorated tent in a park. Using the caravans in the tent as their scenery, they performed self-scripted plays. Around 1992 they decided to have a steel replica of a wooden River Thames (London, England) sailing barge built, to be designed and fabricated in a small dockyard in Kingston, Ontario, Canada. The Thames sailing barges were intended to carry bulk goods such as coal along British coastal waters (e.g. from Newcastle-on-Tyne to London). The stage barge took four years to complete, 30 m length, 7.2 m beam, 1.3 m draft, single mast, fore-and-aft rigged sails, 316 m2 sail area, about 90 tonne displacement. All materials and OEM/COTS (‘original equipment manufacturers’ parts, ‘commercial off-the-shelf’ parts) were donated to the Caravan Stage Company for that purpose, valued about Cdn$ 2,000,000.00. A newly designed superstructure, mast and rigging were intended as the stage for performances, with the audience on shore. The stage barge was intended to be fully independent, with its own power supply (two propulsion diesel motors, two auxiliary diesel motors for lighting and sound systems), galley and sleeping accommodation, etc. The living quarters for the crew (who are also the actors) were installed in the now covered cargo space of the original Thames barge. The author (W.E. Eder) was initially contacted in 1994 by Paul Kirby, producer of the Caravan Stage Company, via the Head of Mechanical Engineering, The Royal Military College of Canada (RMC) to help by designing various needed items. Among these (in 1996) was an arrangement to suspend a life-boat inboard, and swing it out for lowering into the water. Two life-boats were to be installed, and occupy minimum space on the deck. Page 4 of 26

1 Task Defining (P1) establish a design specification for the required system, a list of requirements; Requirements are listed only under the most relevant TrfP- and/or TS-requirements class as judged by the engineering designer, and cross-referenced if they are repeated in any other relevant requirement class, figure 6-3. Indication of priority – F ... fixed requirement, must be fulfilled; S ... strong wish; W ... wish; N ... not considered. Rq1 OrgRq F Rq2 TrfRq F

Organization requirements (Rq1A – Rq1E) Design and manufacture by RMC, Department of Mechanical Engineering. Requirements of the Transformation (Rq2A – Rq2E) Each life-boat (supplied by the Stage Barge) must be suspended inboard above the walkway outside the cabin, and be able to be swung out above the water for lowering and lifting (hoisting equipment supplied by the Stage Barge). F Occupy minimum deck space, must not interfere with the gangway along the boat railings. S Water ingress into the hull should be reduced as much as possible. Rq3 EfRq Effects requirements of the TS (Rq3A – Rq3C) F Provide positive stops for life-boat position at both ends of travel, ‘inboard’ and ‘outboard’. S Minimum chance of fouling to interfere with life-boat movement. Rq4 MfgRq Manufacturing requirements F All fabrication in house at RMC Mech. Eng. Dept., or on site at Stage Barge. Rq5 DiRq Distribution requirements F Direct mount on Stage Barge. Rq6 LiqRq Liquidation requirements F Non-toxic materials – preferably stainless steel Rq7 HuFRq Human factors requirements (Rq7A – Rq7G) S Modifications will be made on board from tests of functionality (e.g. added handles to assist activation if needed) Rq8 TSFRq Requirements of factors of other TS (in their TrfP) (Rq8A – Rq8G) F Must not interfere with other on-board equipment. Rq9 EnvFRq Environment factors requirements, LC1 - LC7 (Rq9A – Rq9B) Page 5 of 26

Rq10 ISFRq Information system factors requirements, LC1 - LC7 (Rq10A – Rq10F) Rq11 MgtFRq Management factors requirements Rq11A Management planning, LC1 Rq11B Management of design and manufacturing process, LC2 - LC4 F Designing and manufacture supervision by author only. Rq11C Design documentation, LC2 F Original drawings and other documentation to remain at RMC, copies held by Stage Barge. Rq11D Situation, LC2 Rq11E Quality system Rq11F Information requirements Rq11G Economic requirements W Only one delivery, all parts and materials delivered by donation, labor donated by RMA Mech. Eng., no economic aspects. Rq11H Time requirements F Delivery and installation before scheduled barge sailing. Rq11J Tangible resources Rq11K Organization Rq11L Supply chain requirements F Obtain donated items and materials before detail design. Rq11M Other management aspects DesRq Engineering design requirements for TrfP(s) and TS(s) (Rq12 – Rq14) None.

(P2) establish a plan and timeline for design engineering; Detail design to be completed before end April 1996.

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2 Conceptualizing (P3a) (P3.1.1) (P3.1.2)

from the desirable and required output (operand in state Od2), establish a suitable transformation process TrfP(s); if needed, establish the appropriate input (operand in state Od1); decide which operations in the TrfP(s) will be performed by technical systems, TS, alone or in mutual cooperation with other operators; and which TS(s) (or parts of them) need to be designed;

Transformation process see figure 8-1. No alternatives were identified.

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(P3.1.3)

establish a technology, Tg, (structure, with alternatives) for that transformation operation, and therefore the effects (as outputs) needed from the technical system;

Available technology alternatives see figure 8-2. Alternative (A) is used in most large ships where deck space is not at a premium. The most promising with least difficulties appears to be ‘(B) vertical pivot’. The angle of rotation from ‘inboard’ to ‘outboard’ is yet to be established.

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(P3b)

establish what the technical system needs to be able to do (its TS-internal and cross-boundary functions, with alternatives);

The TS-function structure developed for this project is shown in figure 8-3. Most of these TS-functions are solvable by routine means. The numbered functions have available alternatives. Part (A) of this figure shows a block-diagram arrangement, as preferred, part (b) shows a hierarchical tree arrangement, see section ‘stage (P3)’, ‘step (P3.2.3)’ in chapter 6.

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(P4) establish what organs (function-carriers in principle and their structure, with alternatives) can perform these functions; Figure 8-4 shows a morphological matrix. Row 2 shows two alternatives for permitting head rotations – the first is preferable because it presents a larger second-moment-of-area at the base (attachment to the deck), where the bending moment on the column is highest.

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Figure 8-5 shows the selected TS-organ structure, in which functions ‘Fu 5' and ‘Fu 7' remain unsolved. This is a skeleton around which the tangible material can be distributed. The author recognized at this point that a further function needed to be added to the function structure, figure 8-3, to prevent an accumulation of water in the upright standing tube, added as Fu 6.

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Swinging the davits (and life-boat) from one position to the other is admittedly not easy, but can be accomplished. An improvement can be achieved (recognized after original publication [148]) by moving the davits to a longer spacing, see figure 8-6.

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3 Embodying/Laying-Out and Detailing (P5a)

establish what constructional parts and their arrangement are needed, in sketch-outline, in rough layout, with alternatives; (P5b) establish what constructional parts are needed, in dimensional-definitive layout, with alternatives; (P6) establish what constructional parts are needed, in detail and assembly drawings, with alternatives. A sample detail drawing and a sample sub-assembly drawing are shown in figure 8-7. In this case, because these drawings are unlikely to be reused, pencil-on-paper was considered adequate. Figure 8-7

Life Boat Davits – Detail and Sub-assembly Drawings [148] (Part 1 of 2)

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Figure 8-7

Life Boat Davits – Detail and Sub-assembly Drawings [148] (Part 2 of 2)

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8.1.4 Sub-problem – Transmit Electrical Power to Stage Barge TS-internal or cross-boundary function Fu7 (see figures 8-3 and 8-4) could now be “elevated” to act as a transformation process, and could thus be solved by a similar systematic design procedure, see figure 8-8, although the solution is intuitively obvious.

The Caravan Stage Company [78] has only delivered one operational comments since its departure from Kingston – a modification required by a marine inspector that caused a failure in the propeller shaft bearing arrangement [139] and required a new bearing.

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Case Example 2: Wine-bottle Corkscrew This is the third re-design case study in the series, see above. New detail drawings were prepared, as reverse-engineered from an available original, see figure 8-9.

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8.2.1 Task Defining (P1) establish a design specification for the required system, a list of requirements; Selected steps from the procedural model, figure 6-1, were considered, and the following review cycle was applied at the end of each main stage of the recommended re-design process: {Improve, optimize} – – {Verify, check, reflect} Requirements are listed only under the most relevant TrfP and/or TS-property (see figure 6-3) as judged by the engineering designer, and cross-referenced if they are repeated in any other relevant property class. Indication of priority – F ... fixed requirement, must be fulfilled; S ... strong wish; W ... wish; N ... not considered. Rq1 OrgRq N Rq2 TrfRq F

Organization requirements (Rq1A – Rq1E) Before selecting a solution, check on its patent status. Requirements of the Transformation (Rq2A – Rq2E) Penetrate cork sufficiently for pulling out without cork-breakage – complete penetration is undesirable, cork crumbs may break off and contaminate the wine. Rq3 EfRq Effects requirements of the TS F Easy to use, especially for inexperienced users (added after revision of requirements) Rq3A FuRq Function requirements – behavior F Provide access to pulled cork on screw to allow its removal from the screw. Rq3B FuDtRq Functionally determined requirements – conditional on TS(s) operating F Operate using axial force and rotational energy obtained from human hand Rq3C OppRq Operational requirements S Continue to function adequately for approximately x years (assume conditions of home or restaurant service). Rq4 MfgRq Manufacturing requirements F Minimize cost of manufacture using equipment available on site and with outside suppliers. Specify in more detail which costs (life cycle) should be reduced (indirect fixed costs or direct costs variable), etc. Rq5 DiRq Distribution requirements S Packed into distribution box (graphic design to be established) for retail. Rq6 LiqRq Liquidation requirements Page 17 of 26

S All materials recyclable Rq7 HuFRq Human factors requirements (Rq7A – Rq7G) F No sharp edges on assembled unit, except where necessary for operation. S Pleasing shape. Rq8 TSFRq Requirements of factors of other TS (in their TrfP) (Rq8A – Rq8G) F Use standard tools and wrenches only. Rq9 EnvFRq Environment factors requirements, LC1 - LC7 (Rq9A – Rq9B) F None Rq10 ISFRq Information system factors requirements, LC1 - LC7 (Rq10A – Rq10F) S None Rq11 MgtFRq Management factors requirements (Rq11A – Rq11M) S Quality Assurance plan? DesRq Engineering design requirements for TrfP(s) and TS(s) (Rq12 – Rq14) N None.

(P2) Establish a Plan for the Design Work – investigate alternatives No anticipated difficulty of design work, guide students in application of design process. Four weeks (3 hours per week) as target for project, see chapter 10. Precedents were available in the literature (a) for operation of design case studies, (b) for commercially available corkscrews. The review cycle was again applied.

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(P3a)

Establish the Transformation Process and Technology – investigate alternatives

See figures 8-10 and 8-11.

PROCEDURAL NOTE 8.2: For a re-design problem, the TrfP and Tg are not required, but can add to understanding of the design situation.

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8.2.2 Reverse Engineering (P1Rev)

Amend Design Specification for New Requirements:

F S W W

Provide force amplification to ease pulling the cork from the bottle. Provide depth stop for cork penetration. Provide a cutting blade to remove shrink-cap from wine bottle. Provide lifting claw for snap-cap soft-drink bottle closure.

(PRev5)

Establish the Existing TS-Organ Structure by Reverse Engineering

The revised design process starts from the existing drawing, figure 8-9. The existing organ structure is shown in figure 8-11.

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(PRev4)

Establish the Existing TS-Function Structure by Reverse Engineering

By searching for significant contacts in both the assembly drawing or TS-constructional structure, and the TS-organ structure, figures 8-9, 8-10 and 8-11, (a) between surfaces on adjoining constructional parts, (b) on constructional parts with the operand and operator, and (c) with the active and reactive environment, elemental organs together with their elemental functions, and organ groups could be identified. Elemental organs were selected to form a typical organ group, and to formulate the appropriate functions – mainly as an educational demonstration exercise to show that elemental organs combine into useful organ groups: Part Feature Part Feature ElOrg 1 A square shaft B square hole ElOrg 2 A 10 mm ø shoulder B flat center section under face ElOrg 3 B flat center section over face C washer under face ElOrg 4 C washer over face D hex. nut under face ElOrg 5 D internal screw thread M4 A external screw thread M4 ElOrgs 1-5 form an organ group with functions: Fu3 ‘Connect handle to screw’ Fu4 ‘Transmit torque to screw’ Fu5 ‘Transmit pull or push force to screw’ The 8 ø extensions of part B form an organ group with human hand, and cross-boundary functions: ‘Accept hand contact’ ‘Accept torque to rotate screw’ ‘Accept axial force to push or pull screw’ These functions only provide opportunities for alternative solutions at the form-giving level, but not at the organ structure level. The corkscrew extension of part A forms an organ group with the cork, and cross-boundary functions: Fu8 ‘Drive corkscrew into cork’ Fu9 ‘Pull cork from bottle neck’ Page 21 of 26

PROCEDURAL NOTE 8.3: As an engineering designer becomes more experienced, the typical organ structure of figure 8-11 is no longer needed, the organ groups and their TS-functions can be ‘read’ directly from the reverse-engineered TS-constructional structure. TS-functions for these organ groups were formulated. The TS-function structure for the revised corkscrew is shown in figure 8-12.

The review cycle was again applied. Page 22 of 26

(P4) Establish the TS(s)-Organ Structure – investigate alternatives A formal morphological matrix is shown in figure 8-13.

The review cycle was again applied.

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The organ structures shown in figure 8-14 were obtained by combining several different partial solutions from figure 8-13.

The original corkscrew appears as item A. Item B is the corkscrew favored by experts, especially waiters in restaurants. Item C is also found among experts, but is common among less experienced wine-drinkers. Items D and E are almost fool-proof, but because the cork is fully penetrated, some cork fragments can occasionally be broken off and contaminate the wine in the bottle.

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8.2.3 Embodying/Laying-Out and Detailing (P5a)

establish what constructional parts and their arrangement are needed, in sketch-outline, in rough layout, with alternatives; (P5b) establish what constructional parts are needed, in dimensional-definitive layout, with alternatives; (P6) establish what constructional parts are needed, in detail and assembly drawings, with alternatives. The subsequent stages and steps from figure 6-1 appear to be routine design work for design engineering and industrial design. We have chosen not to complete these stages and steps. Nevertheless, the importance of these subsequent steps must be emphasized, as many fault conditions may unintentionally be introduced in the embodiment and detail phases.

8.3 Closure The engineering design process is not intended as a linear procedure. Iterative and recursive working is essential, and steps and stages overlap. Various parts of the TrfP(s) and the TS(s) will be in different states of completeness at any one time, this is one aspect of the design situation, part 1 page 27. In all steps of the engineering design process, the problem-solving cycle of basic operations (part 1 page24-26) needs to be applied.

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Thank you Questions?

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