Embedded systems controls
1 / 17

Embedded Systems & Controls - PowerPoint PPT Presentation

  • Uploaded on

Embedded Systems & Controls. Carving Out a Niche as a Mac SE Grad. Kevin Dagenais November 15 2007. Your Presenter. McMaster SE 2003 McMaster MASc 2005 Supervised by M.V.M Theses: Alternate Fuel Injection Control ZENON Environmental/GE Water and Process Hy-Drive Technologies Ltd.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Embedded Systems & Controls' - elise

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Embedded systems controls

Embedded Systems & Controls

Carving Out a Niche as a Mac SE Grad

Kevin Dagenais November 15 2007

Your presenter
Your Presenter

  • McMaster SE 2003

  • McMaster MASc 2005

    • Supervised by M.V.M

    • Theses: Alternate Fuel Injection Control

  • ZENON Environmental/GE Water and Process

  • Hy-Drive Technologies Ltd.

    • Embedded Systems Designer

    • Software Team Leader

State machines and medical supplies
State Machines and Medical Supplies

  • We have a history

    • Intro to Professional Eng 2004-2005

    • I’m sorry if I tricked you into this!

  • 3 Years later… Your Feedback… Please!

Relevant projects
Relevant Projects

  • Design of a Configurable Alternate Fuel Injection Controller

  • Embedded Controls Development for A Hydrogen Generating System

  • Design of gas flow regulation control system. (Just Underway)

  • Telematics Integration, customized reporting.

A green alternative
A Green Alternative

  • Natural Gas and Propane both burn cleaner than Petroleum.

  • These fuels are usually more economical.

  • Because they are Gaseous, injection pulses are longer.

  • A viable solution for localized fleet operators (Taxi companies, Driving Schools).

Injection control
Injection Control

  • Fuel Injector Control

  • Platform: PIC 18F452

  • Hard Real Time Constraints

Injection control system overview
Injection ControlSystem Overview

Main loop
Main Loop

  • Evaluation of Safety and Diagnostic Conditions.

  • Analogue Conversions

  • State variable updates


  • Determine Cause of Interrupt

  • Disable Interrupts and clear flags

  • Handle event

    • Change on Injection Signals (Ext I/O)

    • Pulse Elongation complete (Timer Period Match)

    • Unhandled Exception (Timer Overflow)

A software box that makes hydrogen
A Software Box(That makes Hydrogen)

  • 2 Channel Safety with Monitoring

  • PID Pressure control

  • PWM Heater control

  • Telematics Integration

  • Co-operative Multitasking

  • OTAC

  • Periodic and Failure based reporting

  • Deployed Study performance

  • GPS Integtration

What is out of your control that affects timing
What is out of your control that Affects Timing?

  • Characteristics of the related physical process

  • Hard Real Time Constraints

  • Frequency of Oscillation, Instruction Set, Pipeline Length

  • Available On Chip Peripherals

    • Interrupt handler speed, available interrupts, max # of vectors

    • Timer speed, size, scaling, number, interaction

  • Sensing response time,

    • TAQ, TAC, Sensing Mechanism

  • External communication interfaces

    • Including on-board peripherals

  • Total processor workload

  • The Rest is up to you!!.... (Is there anything left??)

The stuff that s left
The Stuff that’s Left

  • System/State Design

  • Use of Interrupts

  • Extent of branching and conditionals in key processes

  • Extent of context switching

  • Use of Assembly code

  • Task prioritization and scheduling

  • On-Chip peripheral configuration settings

  • Speed vs. Size

  • Task Offloading

Verifying time properties
Verifying Time Properties

  • Design for Inspection, Inspect to Verify!

  • Limit the scope of inspection using interrupts and appropriate priority assignment.

  • Let the compiler documentation do the talking…

  • Lose the printf’s, and all other debugging constructs.

  • Scope it!

When your fastest isn t fast enough salvation through hardware
When Your Fastest Isn’t Fast EnoughSalvation Through Hardware

  • Turn Analogues Inputs to Digitals

  • Move Services off Chip to Dedicated Devices (Flexibility is about choice)

  • Look for opportunities to trade size for speed.

I never thought
I Never Thought…

Anyone would read my thesis.

My Thesis includes complete code (PIC 18F452-C) including:

  • Full Documentation

  • Examples of A/D conversion

  • Interrupt Handling

  • Serial Communication

  • Hard Real time control

    It is available in the departmental office, and in the library.

Closing thoughts
Closing Thoughts

  • Write the PPE Early, but not in Summer.

  • Make good friends with your Hardware Guy/Gal.

  • The Man Month isn’t mythical when you work on Salary.

  • IntelliSense will only get you so far, and Nowhere in embedded.