Automotive Applications of Display Systems and Human-Machine Interfaces using a Dash-Mounted Touch Screen Computer

April 29, 2010

Assim AddousSam CooganSantiago HässigMartin Perry

Dash-Mounted Automotive HMI

EcoCAT Overview

• Automotive Human-Machine Interface (AHMI) to display vehicle information to driver

• Modern vehicles contain wealth of disparate data

• OEMs and car enthusiasts seek a consolidating interface

• Must be below $1,200 to be competitively priced as vehicle upgrade package

Design Objectives

Vehicle Panel

Engine Panel

2-Mode Panel

Electric Panel

GPS Panel

Video Demonstration

Packaging

Hardware Overview

CAN Controller reads in signals from HUB

HMI Computer parses USB data

Hardware SelectionCustom Built CAN Hub•6 DB-9 ports•Vehicle cockpit•Cargo area

NI USB CAN Controller•1 DB-9 Port•Highspeed CAN•500 kBaudLenovo Desktop

•Windows XP Home•x86 Architecture•LabVIEW compatible•6 USB ports

Xenarc 705TS•7.5” display•4-wire, USB touch interface•High viewing angle•Antiglare•800x480 resolution

CAN-bus Topology

Software Development

• LabVIEW Designed– Uses Virtual Instruments (VI) library for CAN

messages– Frame to channel conversion library– Easy to add new signals

• Compiled to standalone executable

• Executable run as OS shell

Acceptance Testing

• Packaged within dash of vehicle

• Demoed in vehicle using previously-obtained data

• Signals replayed by vehicle controller– Data from vehicle run in December– Transparent to AHMI– Displayed data values compared to known

values to ensure accurate display

• Power on– Power applied when ignition moves to accessory– Computer BIOS adjusted to boot when power is applied– Executable runs on OS startup

• Power off– Soft power off switch on display– Handled by driver before car shutdown– Not ideal, but simple and intuitive

• Power integrity– Will not experience power or voltage spikes

Power Handling

Computer Power

• Computer board uses 19V

• Voltage detection on computer prevents lower voltage

• Uses DC-AC inverter and original AC-DC adapter to power PC

Prototype Cost

Prototype Labor

We assume an engineer making $40 per hour, with a 3x multiplier to cover benefits, overhead, etc., resulting in $120 per hour.

Costs for 10,000 Units

Future Work

• Power off initiated by vehicle power off– Requires custom power circuitry

• Embedded operating system– More lightweight for minimal hardware– Quicker boot and shutdown– Cheaper licensing and manufacturing for large scale

implementation

• Map database• Direct DC power to computer

Temperature Control

• Vehicle interior can reach temperatures of up to 120°F

• Have not observed any negative effects

• If implement large scale, hardware would likely not cause issue

• As a prototype, difficult to mitigate

Technical SpecificationsComponent/Topic Specification ActualTouch screenScreen Size 7” – 8” 7.5”Touch control interface USB USB

Display interface VGA VGAPower 12V 12V (native)HMI ComputerMaximum Size 20cm x 12cm x

16.5cmMet

Power 12V 12V (through inverter)Operating system Windows XP

EmbeddedWindows XP Home

USB Interface At least 3 USB 2.0 ports

4 USB 2.0 ports

Technical SpecificationsComponent/Topic Specification ActualCAN ControllerComputer interface USB USBCAN Technology 2-wire, high-speed CAN High-speed or low-speed

CAN Interface DB-9 DB-9Software InterfaceSoftware platform LabVIEW 8.6 LabVIEW 8.6CAN InterfaceWiring No smaller than 20 AWG,

stranded wire 16 AWG, stranded wire

Connector DB-9 DB-9Wiring configuration One pair of twisted-pair

wiring for CAN high and low signaling, one wire for ground

One pair of twisted-pair wiring for CAN high and low signaling, one wire for ground