Embedded Systems in Automobiles By Craig Delzangle Roadmap

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, mp 3 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 80 s • 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 = 2 K 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 1 =6. 4 milliseconds

ECU components • • • 8 -32 bit 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

Terra. Max • Oshkosh Corporation • 6 x 6 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 changed the car The many processors of current cars Self driving vehicles

References • http: //auto. howstuffworks. com/under-thehood/trends-innovations/car-computer 1. htm • “How ECUs Use Closed-Loop Controls to make Fueling Corrections”, Cobb Tuning Inc, 2008 • 1975 Chevrolet Cosworth Vega Overhaul Supplement - general information • http: //www. howstuffworks. com/fuel-injection. htm • http: //www. embedded. com/electronicsblogs/significant-bits/4024611/Motoring-withmicroprocessors • http: //www. slideshare. net/abhisheksutrave/embed ded-systems-in-automobile

Questions?