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ENGR 107: Engineering Fundamentals


Systems Engineering group: preliminary schedule and ... 'real world' example; SUV anti-lock braking system (ABS). Sport Utility ... Anti-lock ... – PowerPoint PPT presentation

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Title: ENGR 107: Engineering Fundamentals

ENGR 107 Engineering Fundamentals
  • Lecture 4
  • The Engineering Design Process
  • The Engineering Method and Problem Solving
  • C. Schaefer
  • September 16, 2002

  • Read Chapter 2 of the textbook.
  • Group Cost ROMs, Bills of Material, and list of
    required tools are due today to the Systems
    Engineering Group.
  • Systems Engineering group preliminary schedule
    and budget due on Wednesday.
  • Groups review hull and keel construction.

The Engineering Method
  • A process within a process.
  • Systems engineering process.
  • Engineering method.
  • The engineering method is the formal approach an
    engineer takes to solve a particular problem.
  • The engineering method is a thought process or
    approach similar to, though not identical to, the
    scientific method.

The Engineering Method1
  • Information gathering.
  • Experimentation.
  • Synthesis.
  • Evaluation and testing.
  • Presentation of solution.
  • Identification of problem.
  • Analysis.
  • Transformation.
  • Alternative solutions.
  • Modeling.

1Engineering An Introduction to a Creative
Profession, G.C. Beakley, D.L. Evans, J.B. Keats
The Engineering Method2
  • Recognize and Understand the Problem.
  • Accumulate Data and Verify Accuracy.
  • Select the Appropriate Theory or Principle.
  • Make Necessary Assumptions.
  • Solve the Problem.
  • Verify and Check Results.

2Engineering Fundamentals and Problem
Solving, A.R. Eide, R.D. Jenison, L.H. Mashaw,
L.L. Northrup
The Engineering Method3
  • Identify and define the problem.
  • Research the problem
  • Accumulate data.
  • Relevant theory.
  • Previous solutions and approaches.
  • Solve the problem
  • Develop alternatives.
  • Modeling/simulation.
  • Experimentation
  • Synthesis
  • Testing and verification.
  • Presentation.

The engineering method is a continuous
feedback loop.
3 My general method of solving engineering
problems. The Schaefer Method.
The Problem With These Approaches?
  • They are predominantly analytical with no
    explicit creative process.
  • Problem solving consists of two elements
  • Creative
  • Analytic
  • Much emphasis in academia and industry on
    analytical methods almost at the exclusion of
    creative processes.

Analytic and Creative Problem Solving1
  • Identify the problem.
  • Define the working criteria or goals.
  • Research and gather data.
  • Brainstorm for creative ideas.
  • Analyze.
  • Develop models and test.
  • Make the decision.
  • Communicate and specify.
  • Implement and commercialize.
  • Prepare post-implementation review and assessment.

1Oakes, et al
Contrast with Scientific Method
  • Define the problem.
  • Gather the facts.
  • Develop a hypothesis.
  • Perform a test.
  • Evaluate the results.
  • Notice that science is not overly concerned with
    implementation, only knowledge gathering.

Lets Look at an Example
  • Simplified real world example SUV anti-lock
    braking system (ABS).

Sport Utility Vehicle (SUV) Anti-Lock Braking
System (ABS)
Identification of Problem
  • What is required?
  • What must be done and why?
  • Scope of problem define problem boundaries.
  • Example Anti-lock Braking System
  • Is it possible to successfully retrofit an ABS
    developed for compact cars to heavier, sports
    utility vehicles?

Research the Problem
  • Can we decompose the problem into easily managed
  • This step defines, for example
  • Literature review for similar problems and
    solutions to those problems.
  • Relevant analytical and modeling techniques.
  • Testing requirements.
  • Design constraints.
  • Resource requirements and allocation.
  • Project schedule.

Research ABS Example
  • Literature search Internet search on ABS.
  • Constraints (example)
  • Retain compact car ABS system architecture.
  • SUV ABS costs cannot exceed 110 of current
    compact car ABS system cost.
  • Time to market 3 months.
  • Performance criteria
  • SUV Total Time to Stop ? 15 increase over
    compact car.
  • SUV Wheel Lock Skid Time ? 10 increase over
    compact car.
  • Approach
  • Develop MATLAB model of ABS system.
  • Parametric analysis using model.
  • Modify system constants.

Solve the Problem
  • Develop alternatives. For example
  • Hardware and software design alternatives.
  • List of independent variables to vary in modeling
    or simulation.
  • Modeling
  • Conceptual models.
  • Physical models and engineering mockups.
  • Graphical models.
  • Mathematical models.
  • Computer models.

Solve the Problem
  • Experimentation
  • Computer simulation.
  • Testing, for example
  • Ground tests.
  • Flight testing.
  • Synthesis
  • Subproblem solutions are merged.
  • E.g., manufacturing and engineering resolving
    issues associated with manufacturability.

Solve Problem ABS Example
  • ABS hardware and system architecture fixed with
    exception of interface to SUV.
  • Control software can be modified.
  • Matlab simulation.
  • Skid pad testing to verify simulation results.
  • Presentation of results to Product Development

ABS Braking Simulation Model
Simulation Results
Vehicle Weight 1600lbs Hydraulic Lag 0.01 sec
Simulation Results
Vehicle Weight 2900 lbs Hydraulic Lag 0.01 sec
Simulation Results
Simulation Results
Vehicle Weight 2900 lbs Hydraulic Lag 0.007
Testing - ABS
Wt 2900 lbs
Is this relationship linear or nonlinear?
Wt 2900 lbs
  • Performance Criteria Satisfied.
  • Total Time to Stop
  • Required ? 15 increase over compact car.
  • Actual 12.8 increase.
  • Wheel Skid Lock Time
  • Required ? 10 increase over compact car.
  • Actual 0 increase over compact car.
  • Time to market 1.5 months for S/W revisions.
  • Cost Less than a 2 increase.
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