P19432: Murphy's Stage
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Systems Design

Table of Contents

Team Vision for System-Level Design Phase

During the systems design phase of MSD I, team MUSIC set out complete a variety of tasks related to the design of our product in regards to it's functions.

Functional Decomposition

A functional decomposition was generated as a method of determining the subsystems within the design.

A Functional Decomposition tree of our project.

A Functional Decomposition tree of our project.

Concept Development and Morphological Chart

Functional Decomposition led to an understanding of the different aspects that required design focus. Through independent consideration and group brainstorming, we were able to establish a list of concepts for each function. This was complied in a morphological chart. Feasible combinations were then compared to one another in a series of Pugh charts.

Morphological Chart, 1 of 2

Morphological Chart, 1 of 2

Morphological Chart, 2 of 2

Morphological Chart, 2 of 2

To assist with the Pugh charting process, team MUSIC narrowed considerations, based on discussion, to a limited number of concepts from two of the function categories.

In discussion, the team concluded that creating a Pugh chart with just two of the main categories would be more valuable to analyze to start.

For transformation method, the team chose to analyze:

For TV/Exhibit Mounting Solution, the team chose to analyze:

Concept Selection

In order to create concepts, the reasonable ideas from each category of the morphological chart were combined to create system level concepts. These concepts were compared to isolate the best options.

Pugh Analysis

To narrow the amount of concepts generated for a more efficient comparison, concepts were generated from only the 'transition method' and 'TV mounting style' categories. Reasonable concepts were compared against the others using a Pugh chart and the a set of predetermined metrics. This Pugh comparison was performed twice, with a different datum each time. Metrics:

Pugh Concept Selection Comparing Transition Method and TV Mounting Method

Pugh Concept Selection Comparing Transition Method and TV Mounting Method

After discussion, the concepts highlighted in green were selected as the best options to move on and should be considered and compared again with the lift assist system taken into account. The options determined to be the most desirable are listed below.

The rotate 90 with expanding sides was not in the original Pugh comparison. The team concluded this concept was more feasible than originally discussed following discussion from the first Pugh analysis. The team decided this concept should be added for further comparison.

Pugh Analysis with Lift Assist The lift assist options selected for being the most reasonable options to implement include: helical springs/gas springs translating linearly, torsional springs, and counter weights.

Pugh Concept Selection Comparing Lift Assist with Desired Options from Previous Comparisons

Pugh Concept Selection Comparing Lift Assist with Desired Options from Previous Comparisons

Following this comparison, the concepts listed below were determined to be the best options for this design problem.

Feasibility: Prototyping, Analysis, Simulation

Feasibility Analysis for Rotate 90° with anti-vibration TV mounts:

Loading condition feasibility:

Assumed Representation of Stage Section

Assumed Representation of Stage Section

Note: This is an assumption of how the stage will be built based on standard design methods.

Assumptions:

Stage Weight Calculation

Stage Weight Calculation

Assuming the stage weight calculated above, and the lift assist force is applied 10 inches behind the pivot point, the following loading scenario is represented:

Stage Loading Condition

Stage Loading Condition

The following calculations determine the force experienced by both the hinge(s) and lift assist.

Derived Force Calculations

Derived Force Calculations

Conclusion Under this loading condition…

Feasibility Analysis for Rotate 90° with Expanding Side Sections

Feasibility Considerations for Garage Door Designs

Benchmarking

Murphy Bed Lift Assist Systems

Helical Spring Lift Assist

Pros

Cons

Gas Spring Lift Assist

Pros

Cons

Click here to view the source of this information.

Quik Stage and similar concepts

The Quik Stage, and other temporary stage solutions like it, is an alternative space-saving stage concept that is simply a stage to pull out of a closet and set up, rather than fold out of a wall.

Garage Door Transformation Method

The garage door transformation method was inspired by the common house-hold item. A few obvious differences are in the orientation, the structure of the item being raised/lowered, and the presence of a motorized lifting apparatus.

Table Leaf Expansion Method

Designs and Flowcharts

Animations of the concepts the selection process converged to are shown below. Click on the individual pictures to view the animation.

90 Degree Rotation Concept Animation

90 Degree Rotation Concept Animation

Garage Door Concept Animation

Garage Door Concept Animation

Rotate 90 With Leaf Extensions Concept Animation

Rotate 90 With Leaf Extensions Concept Animation

Systems Architecture

Schematic diagrams of the desired concepts were developed in order to solidify understanding of the concept.
System Architecture Schematic for 90 Degree Rotation

System Architecture Schematic for 90 Degree Rotation

System Architecture Schematic for Garage Door Concept

System Architecture Schematic for Garage Door Concept

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Risk Assessment

After coming to a consensus on a design concept, Team MUSIC revisited the Risk Analysis developed during the Preliminary Design Phase. A few items were added, and some risks were determined to be less relevant through research, or changes in concept. Some of the more noteworthy changes Include:

Risk Assessment Picture Updated: 10/15/18

Risk Assessment Picture Updated: 10/15/18

Link to live document: here

Design Review Materials

Systems Design Review Presentation

Plans for next phase

Gantt Chart for Systems Design phase
Gantt Chart Picture Updated: 10/15/18

Gantt Chart Picture Updated: 10/15/18

Links to individual 3 week plan:

Vincent D'Arrigo

Jason Schulz

Kevin Leonard

Eric Szyjka


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