Embedded Systems in Automobiles By: Craig Delzangle

Roadmap What is an embedded system? The beginning Electronic Control Unit Other modules The future Summary Questions

What is an Embedded System? Computer system designed with a specific purpose to function within a larger system Examples – cars, phones, mp3 players, medical equipment, etc.

The Beginning First electronic fuel injection (EFI) system developed by Bendix Corporation in 1957 Offered by America Motors Corporation Only used in pre-production cars Less horsepower, expensive, suffered in cold temps.

The Beginning contd. D-Jetronic system developed by Bosch Volkswagen Type 3 – 1967 The system sensed manifold pressure, and engine temp. Turned injectors on and off

First Electronic Control Unit First seen in 1975 Chevrolet Cosworth Vega Received information from 10 sensors Pre-programmed to monitor engine and deliver fuel to cylinders Developed to adhere to stringent emission control requirements Still analog

First microprocessor 1976 Aston Martin Lagonda First to use computer management and LED display Cost three times the budget of the car

Digital ECUs Introduced in the mid 80s First seen in Formula One Closed loop control – monitors engine in real time Sensors – oxygen, throttle position, engine speed, voltage, etc. Uses formulas and lookup tables

Basic Calculation Base Pulse Width – function of Load and RPM RPM = 2K Load = 4 BPW = 8 milliseconds A = coolant temp = 100 B = oxygen level = 3 pulse width = (base pulse width) x (factor A) x (factor B) PW = 8 x.8 x 1 =6.4 milliseconds

ECU components 8-32bit 40 MHz microprocessor Analog-digital converter High-level digital outputs Digital-analog converter Signal conditioner Communication chips ▫controller-area-networking, 500 Kbps

Easier Diagnostics Each module communicates errors to a central module Can communicate errors to a diagnostic tool

Instrument Cluster Displays data about the vehicle in its current state Various modules send data to ECU ECU send a packet of info Cluster module looks for specific headers Cluster is updated

Other modules Antilock Brakes Airbags Security systems Keyless entry Media center Cruise control Seat position and temperature Brake assist Stability control Anti-collision Reverse assist Traction control Self-parking

TerraMax Oshkosh Corporation 6x6 autonomous tactical cargo hauler Uses 64 lasers, 3 forward looking camera, 2 GPS systems

Google’s car To be released in the next 5 years Realistically 2020 Issues ▫Lane markers in snow ▫Un-mapped road changes ▫Traffic officers ▫Performance standard ▫Price

Summary EFI was the start Introduction of ECU ECU changed the car The many processors of current cars Self driving vehicles

References hood/trends-innovations/car-computer1.htm “How ECUs Use Closed-Loop Controls to make Fueling Corrections”, Cobb Tuning Inc, Chevrolet Cosworth Vega Overhaul Supplement - general information blogs/significant-bits/ /Motoring-with- microprocessors ded-systems-in-automobile

Questions?