1 ECE 495 – Integrated System Design I ECE 495 - INTEGRATED SYSTEMS I Engineering Project Planning Timothy Burg

1ECE 495 – Integrated System Design I

ECE 495 - INTEGRATED SYSTEMS I

Engineering Project Planning

Timothy Burg


Career Note – The Five Things Job Recruiters Want From You Now

Recruiters are looking for people with strong records of accomplishment who stand out from others

– Expertise - What special skills do you have?– Success stories - Explain the value you've provided in the past and can

offer in the future.– Recommendations – Colleagues that can explain your concrete

contributions and value to specific projects – Work samples - Examples of what you've done are far more effective

than just talking about what you've done, e.g., websites or pictures.– A consistent message. Your résumé, cover letter, website, LinkedIn

profile and interview remarks should all promote a consistent message– From BMW : Good Grades with practical experience (“grease under

your finger nails”), Coop experience

http://www.forbes.com/2010/06/09/job-recruiters-pointers-leadership-careers-employment.html

What can you do to strengthen your resume?



A few suggestions – (taking the recommended classes is the minimum you can do to get your degree)

– Join a research project (Faculty Research, Creative Inquiry, Robotics Team, ME Battle Bot Team, etc.)

• Success stories, Recommendations, Work Samples– Take extra classes

• Expertise, Success stories (if the course has a large project)– Do well in ECE495, make a good website

• Expertise, Success stories, Recommendations– Do well in your remaining courses

• Show a positive slope in your grades, you are on an increasing trajectory

– Summer Research Project (REU)• Success stories, flexibility

No magic solutions, make a plan to improve your resume.



Get to know a faulty member.

ECE 495 – Integrated System Design I

Note about Personality Profiles HW

Computer Programmer

Electrical Engineer

Lawyer

Artist

Social Worker

47

4 3

3

2

2

1

1

1

1

1

1

Spring 2013


Note about Personality Profiles HW

Extraversion 48 iNtuition 51 Thinking 64 Judging 83Introversion 52 Sensing 49 Feeling 36 Perceiving 17

Your group probably has a similar distribution, work to incorporate everyone’s talents


Design Example: Airbus A350

A six-month delay in the launch of Airbus’s A350XWB jet cost parent company EADS (European Aeronautic Defense and Space Company) NV $273-million in the third quarter of 2011.

Scheduling is a critical part of any design project.


Generic Design Process

All activities in the design process should be planned.

IdentifyNeed Research

Requirements

Concepts

Design

Prototype

Testing

Retire

Maintain

Use by Customer(s)

Distribute and Sell

Manufacture


Engineering Project Management

• If you fail to plan, then you plan to fail.• Industrial Scheduling Tools

– Work Breakdown Schedule (WBS)– GANTT Chart

• Illustration of the WBS through a visual display of project task durations

– Network Diagram• Illustration of the WBS through a visual display of a

task dependencies


Work Breakdown Schedule (WBS)

• Activity = Task + Deliverable– Tasks are actions that accomplish a job– Deliverables are the outcome of the task

• WBS describes– Work to be done– Time frame for completion– Resources needed– Responsible person– Predecessors or dependencies– Checkpoints

For planning, you need to know:What has to be done?Who will do it?When will they finish?

Design a timing circuit


Example: Design a Robotic Arm for an Underwater Vehicle

High-level view of “Work to be done”



More Details of “Work to be done”Define Deliverables

Deliverable



Time frame for completionResources neededPredecessors or dependencies

Constraints limiting when an activity can begin (weather, resources, ..)

Can’t start some activities until others finish

Must complete WBS for the entire project



• Estimating time and resources is a difficult task• Routine tasks are well known and quantified

– Solder 16 wire cable to a connector– Replace fan motor

• New tasks are more difficult to estimate. How long does it take to perform the following tasks?– Design a small user interface with 3 data fields and

4 buttons?– Write a 10 line C++ function?– Purchase a socket wrench



• US Navy developed probability model to estimate the duration of a task:

ta = most optimistic

tm= most realistic

tb=most pessimistic

4

6a m b

e

t t tt

• How long did it take your group to install Simulink and C++ and then perform the first analog loopback?

4 1 4 1.5 41.8

6 6a m b

e

t t t hr hr hrt hr



• The WBS alone is not very “user friendly”

It would be difficult to manage a team working on a complex project based on this table alone.


Gantt Chart

• Graphically represents the Work Breakdown Schedule and the Timeline

• Bars show length of task• Connections show dependencies between tasks.• Software: VISIO, MS Project, OpenGantt



Start of activity

Dependency: can’t start this task until three others finish

Tasks and milestones from WBS

Insight”: any change in 3rd task affects the 4th task

Time (hours, days, years)

Length of activity

Insight: Could delay the start of the 1st task or take longer without affecting the 4th task


Network Diagram

• Graphically represents the Work Breakdown Schedule

• A directed graph representation of activities and dependencies

Task ID

Duration

Task Flow


Network Diagram

• Critical path : – The series of tasks that must be completed on

schedule for a project to finish on schedule. – Minimum time to complete the schedule– Any delay in the critical path will delay the

project.14 days

15 days


Network Diagram

• Example Critical path (d=day)

20d

8d

15d

16d

19d

1.13d

1.2.14d

2.31d

3.13d

3.24d

3.35d

3.46d

1.2.25d

2.16d 15d

Insight: Need to carefully manage the red path because it will directly delay the project



Red boxes and lines indicate the Critical Path to Identify NeedThe surveys and Market Analysis could take longer without extending the projects.



“Slack” or “Float” is the maximum delay in activity before it affects the critical path.


Summary

• Time Management Tools– Work Breakdown Schedule– Gantt Chart– Network Diagram

Project management is another important element of the design process.

These are very similar and most software let you switch between views


Project 6 WBS


Project 6 WBS


Project 6 WBS


Project 6 Gantt Chart


ECE495 Webpage

All equipment manualsProject

detailsIndividual Assignments


Project 1 – Laser Cut Part

• Laser Cutter Process– Download Template– Draw interesting pattern in 4” square– Submit to Ran by Friday– Meet TA in 403 Rhodes to use cutter


Project 1

• Configure hardware• Test analog loopback• Test other loopbacks• Test incremental (Q4 only counts increments from the

point it is switched “on”) quadrature encoder input• Report due on next Friday


HIL in the loop

Li Ri v

Model of a DC Motor

Control Algorithm

Simulink Program

Target Computer

Analog Out

Encoder In

DC Motor

AmplifierQ4

Simulation

HIL Simulation


Real-time Control


Hardware-in-the-Loop (HIL) System

Can’t model all of the subsystems to build a complete simulation

Physical

Computer simulation of a system containing connected subsystem models

Input SignalsA complex physical subsystem that can’t be effectively modeledConvert

A/D, Buffer

ConvertD/A, Buffer

Input Signals

Simulated

HIL Simulation is a hybrid simulation that incorporates real components


Hardware-in-the-Loop (HIL) System Example

To determine which ABS module would be best without actually building a car and testing each different module, simulate the car’s dynamics, test different controllers, and analyze simulated response of the car to real ABS braking signals.

HIL Card

Braking SignalsComputer simulation of a car including vehicle dynamics, tire models, driver models, etc.

Anti-Lock Brake Module

Car State Signals(speed, driver command)

A complex physical system that can’t be effectively modeled

Need hardware and software


Open-loop Control System

Open-loop control:• Input designed to move the system to a desired state based on current

conditions and model of the system.• Example: Fill a water tank to a specified level based on flow-rate and time.

• If some of the water evaporates during filling then the level will be wrong

• If flow rate is not exactly as expected then the level will be wrong.• Inaccurate time will lead to the wrong level

Desired level

Actual level

No correction for errors


Closed-Loop Control System

Closed-loop control:• Input changes as the error, difference between the desired output and the

measured output, changes.• Example – fill a tank to a specified level based on measuring the tank level

and turning flow “on” or “off” to reach the desired level.• Anything that prevents the tank from being filled to the desired level

will be compensated.

Desired level = Actual level

SystemOutput

Feedback

Desired level

+_

Input Error = Desired Level – Measured

Measurement


Real-time (RT) System

Computer-based execution of a program loop:

Instructions or algorithm

System

Speed and predictability of execution times distinguish RT and non-RT systems

Real-time system: the correctness of the system behavior depends not only on the logical results of the computations, but also on the physical instant at which these results are produced.

http://www.ece.cmu.edu/~koopman/des_s99/real_time/

input outputτ, response time


Closed-Loop Control as a RT, HIL Simulation

Amplifier

Motor

If you were using closed-loop control on the position of the motor, you would want the motor to stop at a certain shaft angle.

HIL Card

Motor Position (encoder)

Control Algorithm (like you are learning in ECE409)

Voltage

PhysicalSimulated


Implementing Closed-Loop Control as a RT, HIL Simulation in ECE495

SystemOutput

Feedback

+_

Input

Target PC • xPC OS from

Mathworks• Q4 HIL Board

Simulation

A/D,D/A, Buffer



SystemOutput

Feedback

+_

Input

Target PC • xPC OS from

Mathworks• Q4 HIL Board

Host• MATLAB with

Simulink• C++

• Programming Interface to Target PC• User Interface• Execute High-level Programs

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MATLAB/SIMULINK have a toolbox called xPC Target



Design a Simulink model on the host PC

Program is downloaded to target for real-time execution

Boot CD installs a real-time kernel on target

Build the Simulink model Host and target coordinate for downloading programs

Some parameters can be changed on host. This change is communicated to target.

Host Computer Target ComputerWorkflow



• 4 x 14 bit Analog Inputs• 4 x 12 bit D/A Outputs• 4 Quadrature Encoder Inputs• 16 Programmable Digital IO

Channels• 2 x 32 bit dedicated Counter/ Timers• 2 External Interrupt sources• 32 bit, 33MHz PCI Bus Interface

Quanser Q4 card in the Target PC

Terminal board



Analog Out (D/A)

Channels

Ext Interrupt and Signal Pins (PWM,Watchdog)

Analog In (A/D)

Channels

Encoder

Channels

Digital I/O Ports

From Q4 board

Q4 Terminal Board


Why MATLAB/SIMULINK over C++?

• MATLAB is a huge collection of C/C++ libraries for system prototyping and hardware interfacing.

• No need to reinvent the wheel! Would you rather spend weeks writing device drivers and libraries for the Q4 than test your system in a few hours?

• Prototyping ideas is easy and fast.

• Visualization of data is easy.


Final Note - Response to comment

• EEs believe these are "computer" projects. This could not be much further from the truth; we use high-level tools like Simulink so that it does NOT become a computer project.

• There is a local culture that EEs don't program. In almost every industrial, military, financial, civil, medical, political … endeavor, the automated gathering, processing, and use of data have created significant breakthroughs.

• For example, the conservative field of power generation and distribution has become a "computer" problem in the sense that "A smart grid is an electrical grid that uses information and communications technology to gather and act on information, such as information about the behaviors of suppliers and consumers, in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity. [Wikipedia]“

• My hope is that you appreciate that automation tools (like the image processing functions in MATLAB) can enable you to apply your expertise in power systems, communications, robotics, electronics, electromagnetics, etc. to create new solutions.


Extra Slides


Real-time Closed-loop Control

Typical response times and the applications which need them …

Seconds : Temperature, pressure, and flow control; aircraft control

Milliseconds (control with < 1 kHz): Productions lines, motor control, robot control

Microseconds : High speed test stands, fast digital controllers, control with 5 kHz – 500 kHz


How is a Real-time System formulated?

More generally, to Relate Theory to Application

ContinuousProcess

DigitalSystem

Model ofContinuousProcess

1. Want to measure or control this process

2. Use engineering tools to model the process using continuous or fixed sample time discrete models(For example ECE409, ECE 467)

3. Formulate interaction algorithms based on the models(For example ECE409, ECE 467)

4. Execute algorithms(assume a continuous system can be approximated by a “fast” digital system)

Design

Error if execution timing doesn’t match assumptions in model and algorithms - results are not predictable.


Classification of Real-time Systems

http://www.ece.cmu.edu/~koopman/des_s99/real_time/

Real-time System

Soft Hard

Dynamic Static

System must remain synchronous with the state of the environment.

Degraded operation in a rarely occurring peak load can be tolerated.

Timing parameters for the system are set during compilation.

Timing parameters and the priority for tasks is modified at run-time.


HardReal-timeSystem

SoftReal-timeSystem

Example: Produce a sinusoid output

D/A

D/A

Error in output waveform

Error in execution time

Classification of Real-time Systems


Examples of Real-time Systems

QUARC from QuanserSoft Real-time System using PC with Windows

QUARC from QuanserHard Real-time System using QNX


Which system would you use in ECE 495?

Real-time System

Soft Hard

Dynamic Static

Systems

Non-Real-time System

Speed and predictability are both critical

Response to input has to come at a precise time

System timing parameters are known before execution

In ECE 495, we use a Static, Hard Real-Time System


A final thought …

The Q4 cards being used for data acquisition and control are very useful… and very expensive. Read the manuals for voltage limitations and proper use.


The utility of MATLAB Simulink

MATLAB/Simulink are used to prototype, simulate and visualize performance of systems.

Math model of system

MATLAB Simulink Model

Visualization: Plots, Scopes, etc.


Using C/C++ Code in MATLAB

• MATLAB allows the use of user defined C/C++ executables (MEX files) to augment functionality.

• Computationally expensive tasks can be carried out using C and data can be sent to MATLAB. E.g. Camera interfacing for image processing.

• Specific manipulation of data can be programmed into a user defined function (called the S-function) in Simulink. S-functions are C-code snippets embedded in the Simulink environment.

Documents

1 ECE 495 – Integrated System Design I ECE 495 - INTEGRATED SYSTEMS I Engineering Project Planning Timothy Burg