+----------------+-----+----------+-----------+---+---+-----------------+
| **REPORT       |     |          |           | * |   |                 |
| DOCUMENTATION  |     |          |           | F |   |                 |
| PAGE**         |     |          |           | o |   |                 |
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+----------------+-----+----------+-----------+---+---+-----------------+
| Public         |     |          |           |   |   |                 |
| reporting      |     |          |           |   |   |                 |
| burden for     |     |          |           |   |   |                 |
| this           |     |          |           |   |   |                 |
| collection of  |     |          |           |   |   |                 |
| information is |     |          |           |   |   |                 |
| estimated to   |     |          |           |   |   |                 |
| average 1 hour |     |          |           |   |   |                 |
| per response,  |     |          |           |   |   |                 |
| including the  |     |          |           |   |   |                 |
| time for       |     |          |           |   |   |                 |
| reviewing      |     |          |           |   |   |                 |
| instructions,  |     |          |           |   |   |                 |
| searching      |     |          |           |   |   |                 |
| existing data  |     |          |           |   |   |                 |
| sources,       |     |          |           |   |   |                 |
| gathering and  |     |          |           |   |   |                 |
| maintaining    |     |          |           |   |   |                 |
| the data       |     |          |           |   |   |                 |
| needed, and    |     |          |           |   |   |                 |
| completing and |     |          |           |   |   |                 |
| reviewing the  |     |          |           |   |   |                 |
| collection of  |     |          |           |   |   |                 |
| information.   |     |          |           |   |   |                 |
| Send comments  |     |          |           |   |   |                 |
| regarding this |     |          |           |   |   |                 |
| burden         |     |          |           |   |   |                 |
| estimate or    |     |          |           |   |   |                 |
| any other      |     |          |           |   |   |                 |
| aspect of this |     |          |           |   |   |                 |
| collection of  |     |          |           |   |   |                 |
| information,   |     |          |           |   |   |                 |
| including      |     |          |           |   |   |                 |
| suggestions    |     |          |           |   |   |                 |
| for reducing   |     |          |           |   |   |                 |
| this burden,   |     |          |           |   |   |                 |
| to Washington  |     |          |           |   |   |                 |
| Headquarters   |     |          |           |   |   |                 |
| Services,      |     |          |           |   |   |                 |
| Directorate    |     |          |           |   |   |                 |
| for            |     |          |           |   |   |                 |
| Information    |     |          |           |   |   |                 |
| Operations and |     |          |           |   |   |                 |
| Reports, 1215  |     |          |           |   |   |                 |
| Jefferson      |     |          |           |   |   |                 |
| Davis Highway, |     |          |           |   |   |                 |
| Suite 1204,    |     |          |           |   |   |                 |
| Arlington, VA  |     |          |           |   |   |                 |
| 22202-4302,    |     |          |           |   |   |                 |
| and to the     |     |          |           |   |   |                 |
| Office of      |     |          |           |   |   |                 |
| Management and |     |          |           |   |   |                 |
| Budget,        |     |          |           |   |   |                 |
| Paperwork      |     |          |           |   |   |                 |
| Reduction      |     |          |           |   |   |                 |
| Project        |     |          |           |   |   |                 |
| (0704-0188),   |     |          |           |   |   |                 |
| Washington, DC |     |          |           |   |   |                 |
| 20503.         |     |          |           |   |   |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 1\. AGENCY USE |     | 2\.      |           | 3 |   |                 |
| ONLY (Leave    |     | REPORT   |           | \ |   |                 |
| blank)         |     | DATE     |           | . |   |                 |
|                |     |          |           | R |   |                 |
|                |     | December |           | E |   |                 |
|                |     | 2004     |           | P |   |                 |
|                |     |          |           | O |   |                 |
|                |     |          |           | R |   |                 |
|                |     |          |           | T |   |                 |
|                |     |          |           | T |   |                 |
|                |     |          |           | Y |   |                 |
|                |     |          |           | P |   |                 |
|                |     |          |           | E |   |                 |
|                |     |          |           | A |   |                 |
|                |     |          |           | N |   |                 |
|                |     |          |           | D |   |                 |
|                |     |          |           | D |   |                 |
|                |     |          |           | A |   |                 |
|                |     |          |           | T |   |                 |
|                |     |          |           | E |   |                 |
|                |     |          |           | S |   |                 |
|                |     |          |           | C |   |                 |
|                |     |          |           | O |   |                 |
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|                |     |          |           | E |   |                 |
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|                |     |          |           | A |   |                 |
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|                |     |          |           | 2 |   |                 |
|                |     |          |           | - |   |                 |
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|                |     |          |           | M |   |                 |
|                |     |          |           | a |   |                 |
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+----------------+-----+----------+-----------+---+---+-----------------+
| 4\. TITLE AND  |     |          |           |   | 5 |                 |
| SUBTITLE       |     |          |           |   | \ |                 |
|                |     |          |           |   | . |                 |
| Transit Bus    |     |          |           |   | F |                 |
| Collision      |     |          |           |   | U |                 |
| Warning        |     |          |           |   | N |                 |
| System:        |     |          |           |   | D |                 |
| Integrated     |     |          |           |   | I |                 |
| Transit        |     |          |           |   | N |                 |
| Collision      |     |          |           |   | G |                 |
| Warning        |     |          |           |   | N |                 |
| Systems        |     |          |           |   | U |                 |
| Interface      |     |          |           |   | M |                 |
| Control        |     |          |           |   | B |                 |
| Document       |     |          |           |   | E |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   | S |                 |
|                |     |          |           |   |   |                 |
|                |     |          |           |   | F |                 |
|                |     |          |           |   | e |                 |
|                |     |          |           |   | d |                 |
|                |     |          |           |   | e |                 |
|                |     |          |           |   | r |                 |
|                |     |          |           |   | a |                 |
|                |     |          |           |   | l |                 |
|                |     |          |           |   | I |                 |
|                |     |          |           |   | D |                 |
|                |     |          |           |   | \ |                 |
|                |     |          |           |   | # |                 |
|                |     |          |           |   | 2 |                 |
|                |     |          |           |   | 5 |                 |
|                |     |          |           |   | 0 |                 |
|                |     |          |           |   | 9 |                 |
|                |     |          |           |   | 6 |                 |
|                |     |          |           |   | 9 |                 |
|                |     |          |           |   | 4 |                 |
|                |     |          |           |   | 4 |                 |
|                |     |          |           |   | 9 |                 |
|                |     |          |           |   | 0 |                 |
|                |     |          |           |   | 0 |                 |
|                |     |          |           |   | 0 |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 6\. AUTHOR(S)  |     |          |           |   |   |                 |
|                |     |          |           |   |   |                 |
| University of  |     |          |           |   |   |                 |
| California     |     |          |           |   |   |                 |
| PATH, Carnegie |     |          |           |   |   |                 |
| Mellon         |     |          |           |   |   |                 |
| University     |     |          |           |   |   |                 |
| Robotics       |     |          |           |   |   |                 |
| Institute      |     |          |           |   |   |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 7\. PERFORMING |     |          |           |   | 8 |                 |
| ORGANIZATION   |     |          |           |   | \ |                 |
| NAME(S) AND    |     |          |           |   | . |                 |
| ADDRESS(ES)    |     |          |           |   | P |                 |
|                |     |          |           |   | E |                 |
| University of  |     |          |           |   | R |                 |
| California     |     |          |           |   | F |                 |
| PATH Carnegie  |     |          |           |   | O |                 |
| Mellon         |     |          |           |   | R |                 |
| University     |     |          |           |   | M |                 |
| Robotics       |     |          |           |   | I |                 |
| Institute      |     |          |           |   | N |                 |
|                |     |          |           |   | G |                 |
| 5000 Forbes    |     |          |           |   | O |                 |
| Ave            |     |          |           |   | R |                 |
|                |     |          |           |   | G |                 |
| Pittsburgh, PA |     |          |           |   | A |                 |
| 15213          |     |          |           |   | N |                 |
|                |     |          |           |   | I |                 |
|                |     |          |           |   | Z |                 |
|                |     |          |           |   | A |                 |
|                |     |          |           |   | T |                 |
|                |     |          |           |   | I |                 |
|                |     |          |           |   | O |                 |
|                |     |          |           |   | N |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   | E |                 |
|                |     |          |           |   | P |                 |
|                |     |          |           |   | O |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   | T |                 |
|                |     |          |           |   | N |                 |
|                |     |          |           |   | U |                 |
|                |     |          |           |   | M |                 |
|                |     |          |           |   | B |                 |
|                |     |          |           |   | E |                 |
|                |     |          |           |   | R |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 9\.            |     |          |           |   | 1 |                 |
| SPONSOR        |     |          |           |   | 0 |                 |
| ING/MONITORING |     |          |           |   | \ |                 |
| AGENCY NAME(S) |     |          |           |   | . |                 |
| AND            |     |          |           |   | S |                 |
| ADDRESS(ES)    |     |          |           |   | P |                 |
|                |     |          |           |   | O |                 |
| U.S.           |     |          |           |   | N |                 |
| Department of  |     |          |           |   | S |                 |
| T              |     |          |           |   | O |                 |
| ransportation, |     |          |           |   | R |                 |
| Federal        |     |          |           |   | I |                 |
| Transit        |     |          |           |   | N |                 |
| Administration |     |          |           |   | G |                 |
|                |     |          |           |   | / |                 |
| 400 Seventh    |     |          |           |   | M |                 |
| Street, S. W.  |     |          |           |   | O |                 |
|                |     |          |           |   | N |                 |
| Washington, D. |     |          |           |   | I |                 |
| C. 20590       |     |          |           |   | T |                 |
|                |     |          |           |   | O |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   | I |                 |
|                |     |          |           |   | N |                 |
|                |     |          |           |   | G |                 |
|                |     |          |           |   | \ |                 |
|                |     |          |           |   | A |                 |
|                |     |          |           |   | G |                 |
|                |     |          |           |   | E |                 |
|                |     |          |           |   | N |                 |
|                |     |          |           |   | C |                 |
|                |     |          |           |   | Y |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   | E |                 |
|                |     |          |           |   | P |                 |
|                |     |          |           |   | O |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   | T |                 |
|                |     |          |           |   | N |                 |
|                |     |          |           |   | U |                 |
|                |     |          |           |   | M |                 |
|                |     |          |           |   | B |                 |
|                |     |          |           |   | E |                 |
|                |     |          |           |   | R |                 |
|                |     |          |           |   |   |                 |
|                |     |          |           |   | F |                 |
|                |     |          |           |   | H |                 |
|                |     |          |           |   | W |                 |
|                |     |          |           |   | A |                 |
|                |     |          |           |   | - |                 |
|                |     |          |           |   | J |                 |
|                |     |          |           |   | P |                 |
|                |     |          |           |   | O |                 |
|                |     |          |           |   | - |                 |
|                |     |          |           |   | 0 |                 |
|                |     |          |           |   | 4 |                 |
|                |     |          |           |   | - |                 |
|                |     |          |           |   | 0 |                 |
|                |     |          |           |   | 9 |                 |
|                |     |          |           |   | 7 |                 |
|                |     |          |           |   |   |                 |
|                |     |          |           |   | F |                 |
|                |     |          |           |   | T |                 |
|                |     |          |           |   | A |                 |
|                |     |          |           |   | - |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 11\.           |     |          |           |   |   |                 |
| SUPPLEMENTARY  |     |          |           |   |   |                 |
| NOTES          |     |          |           |   |   |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 12a.           |     |          |           |   | 1 |                 |
| DISTRIBUTIO    |     |          |           |   | 2 |                 |
| N/AVAILABILITY |     |          |           |   | b |                 |
| STATEMENT \--  |     |          |           |   | . |                 |
| Available from |     |          |           |   | D |                 |
| the National   |     |          |           |   | I |                 |
| Technical      |     |          |           |   | S |                 |
| Information    |     |          |           |   | T |                 |
| Service/NTIS,  |     |          |           |   | R |                 |
| Springfield,   |     |          |           |   | I |                 |
| Virginia,      |     |          |           |   | B |                 |
| 22161. Phone   |     |          |           |   | U |                 |
| 703.605.6000,  |     |          |           |   | T |                 |
| Fax            |     |          |           |   | I |                 |
| 703.605.6900,  |     |          |           |   | O |                 |
| Email          |     |          |           |   | N |                 |
| \[orders@ntis. |     |          |           |   | C |                 |
| fedworld.gov\] |     |          |           |   | O |                 |
|                |     |          |           |   | D |                 |
|                |     |          |           |   | E |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 13\. ABSTRACT  |     |          |           |   |   |                 |
| (Maximum 200   |     |          |           |   |   |                 |
| words)         |     |          |           |   |   |                 |
|                |     |          |           |   |   |                 |
| The Integrated |     |          |           |   |   |                 |
| collision      |     |          |           |   |   |                 |
| warning system |     |          |           |   |   |                 |
| (ICWS) is to   |     |          |           |   |   |                 |
| predict        |     |          |           |   |   |                 |
| imminent       |     |          |           |   |   |                 |
| potential      |     |          |           |   |   |                 |
| crashes, or    |     |          |           |   |   |                 |
| collisions     |     |          |           |   |   |                 |
| with objects   |     |          |           |   |   |                 |
| and warn the   |     |          |           |   |   |                 |
| transit        |     |          |           |   |   |                 |
| operator. The  |     |          |           |   |   |                 |
| goal of the    |     |          |           |   |   |                 |
| ICWS program   |     |          |           |   |   |                 |
| is to          |     |          |           |   |   |                 |
| integrate the  |     |          |           |   |   |                 |
| advanced       |     |          |           |   |   |                 |
| frontal and    |     |          |           |   |   |                 |
| side collision |     |          |           |   |   |                 |
| warning        |     |          |           |   |   |                 |
| systems into a |     |          |           |   |   |                 |
| integrated     |     |          |           |   |   |                 |
| collision      |     |          |           |   |   |                 |
| warning system |     |          |           |   |   |                 |
| with a Driver  |     |          |           |   |   |                 |
| Vehicle        |     |          |           |   |   |                 |
| Interface      |     |          |           |   |   |                 |
| (DVI) that can |     |          |           |   |   |                 |
| effectively    |     |          |           |   |   |                 |
| display        |     |          |           |   |   |                 |
| warnings from  |     |          |           |   |   |                 |
| both frontal   |     |          |           |   |   |                 |
| and side       |     |          |           |   |   |                 |
| collision      |     |          |           |   |   |                 |
| warning        |     |          |           |   |   |                 |
| system,        |     |          |           |   |   |                 |
| signaling the  |     |          |           |   |   |                 |
| driver in a    |     |          |           |   |   |                 |
| manner that is |     |          |           |   |   |                 |
| effective in   |     |          |           |   |   |                 |
| avoiding       |     |          |           |   |   |                 |
| potential      |     |          |           |   |   |                 |
| accidents.     |     |          |           |   |   |                 |
| Under this     |     |          |           |   |   |                 |
| program, a     |     |          |           |   |   |                 |
| functional     |     |          |           |   |   |                 |
| transit ICWS   |     |          |           |   |   |                 |
| was developed. |     |          |           |   |   |                 |
| This Interface |     |          |           |   |   |                 |
| Control        |     |          |           |   |   |                 |
| Document (ICD) |     |          |           |   |   |                 |
| was to define  |     |          |           |   |   |                 |
| the            |     |          |           |   |   |                 |
| architecture   |     |          |           |   |   |                 |
| of the         |     |          |           |   |   |                 |
| Integrated     |     |          |           |   |   |                 |
| Collision      |     |          |           |   |   |                 |
| Warning System |     |          |           |   |   |                 |
| (ICWS) and the |     |          |           |   |   |                 |
| physical,      |     |          |           |   |   |                 |
| electrical and |     |          |           |   |   |                 |
| electronic     |     |          |           |   |   |                 |
| interface      |     |          |           |   |   |                 |
| among          |     |          |           |   |   |                 |
| different      |     |          |           |   |   |                 |
| components.    |     |          |           |   |   |                 |
| This is the    |     |          |           |   |   |                 |
| final document |     |          |           |   |   |                 |
| for the        |     |          |           |   |   |                 |
| installation   |     |          |           |   |   |                 |
| of the         |     |          |           |   |   |                 |
| Integrated     |     |          |           |   |   |                 |
| Collision      |     |          |           |   |   |                 |
| Warning System |     |          |           |   |   |                 |
| on a transit   |     |          |           |   |   |                 |
| bus.           |     |          |           |   |   |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
| 14\. SUBJECT   |     |          |           |   |   | 15\. NUMBER OF  |
| TERMS          |     |          |           |   |   | PAGES           |
|                |     |          |           |   |   |                 |
| ICWS,          |     |          |           |   |   |                 |
| Collision      |     |          |           |   |   |                 |
| Warning,       |     |          |           |   |   |                 |
| Transit bus    |     |          |           |   |   |                 |
| safety         |     |          |           |   |   |                 |
+----------------+-----+----------+-----------+---+---+-----------------+
|                |     |          |           |   |   | 16\. PRICE CODE |
+----------------+-----+----------+-----------+---+---+-----------------+
| 17\. SECURITY  | 1   |          | 19\.      |   |   | 20\. LIMITATION |
| C              | 8\. |          | SECURITY  |   |   | OF ABSTRACT     |
| LASSIFICATION\ | SE  |          | CLASSI    |   |   |                 |
| OF REPORT      | CUR |          | FICATION\ |   |   |                 |
|                | ITY |          | OF        |   |   |                 |
| Unclassified   | CLA |          | ABSTRACT  |   |   |                 |
|                | SSI |          |           |   |   |                 |
|                | FIC |          | Unc       |   |   |                 |
|                | ATI |          | lassified |   |   |                 |
|                | ON\ |          |           |   |   |                 |
|                | OF  |          |           |   |   |                 |
|                | T   |          |           |   |   |                 |
|                | HIS |          |           |   |   |                 |
|                | P   |          |           |   |   |                 |
|                | AGE |          |           |   |   |                 |
|                |     |          |           |   |   |                 |
|                | Unc |          |           |   |   |                 |
|                | las |          |           |   |   |                 |
|                | sif |          |           |   |   |                 |
|                | ied |          |           |   |   |                 |
+----------------+-----+----------+-----------+---+---+-----------------+

NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. 239-18298-102

Transit Bus Collision Warning Systems:

**Integrated Collision Warning System**

**Interface Control Document**

December 2004

*Prepared by:*

+-----------------------------------+-----------------------------------+
| *Carnegie Mellon University*      | *University of California at      |
|                                   | Berkeley*                         |
| *Robotics Institute*              |                                   |
|                                   | *PATH Program*                    |
| *5000 Forbes Ave*                 |                                   |
|                                   | *1357 South 46^th^ Street*        |
| *Pittsburgh, PA 15213*            |                                   |
|                                   | *Richmond, CA 94804*              |
+-----------------------------------+-----------------------------------+

Prepared for:

*U.S. Department of Transportation*

*Federal Transit Administration*

*Washington, DC 20590*

Report Number:

FHWA-JPO-04-097

**Disclaimer Notice**

Integrated Collision Warning System

**Interface Control Document**

[1. Introduction 4](#__RefHeading___Toc80087222)

[2. System Architecture 5](#system-architecture)

[3. Mechanical 7](#mechanical)

[3.1. Computer enclosure layouts 7](#computer-enclosure-layouts)

[3.1.1. Electronics power conditioning and power supplies
7](#electronics-power-conditioning-and-power-supplies)

[3.1.2. Sensor power conditioning and power supplies
8](#sensor-power-conditioning-and-power-supplies)

[3.1.3. Power up and shutdown circuitry
8](#power-up-and-shutdown-circuitry)

[3.2. Sensor mounting 9](#sensor-mounting)

[3.2.1. FCWS object sensors 9](#fcws-object-sensors)

[3.2.2. FCWS cameras 11](#fcws-cameras)

[3.2.3. FCWS Host-bus sensors 11](#fcws-host-bus-sensors)

[3.2.4. SCWS Sensor Layout 12](#scws-sensor-layout)

[3.2.5. SCWS object sensors 12](#scws-object-sensors)

[3.2.6. SCWS cameras 13](#scws-cameras)

[3.2.7. SCWS Host-bus sensors 14](#scws-host-bus-sensors)

[3.3. Driver Vehicle Interface 14](#driver-vehicle-interface)

[3.4. Sensors Field of View 15](#sensors-field-of-view)

[3.5. Cable routing 16](#cable-routing)

[4. Power 17](#__RefHeading___Toc80087242)

[4.1. Power Allocation by Subsystems 17](#__RefHeading___Toc80087243)

[4.1.1. Electronics Enclosure 17](#__RefHeading___Toc80087244)

[4.1.2. Sensors 17](#__RefHeading___Toc80087246)

[4.1.3. DVI 18](#__RefHeading___Toc80087247)

[4.2. Power Conditioning 18](#__RefHeading___Toc80087248)

[4.3. Grounding Scheme 18](#__RefHeading___Toc80087249)

[4.4. Maximum Power 19](#__RefHeading___Toc80087250)

[5. FCWS Engineering Computer 20](#__RefHeading___Toc80087251)

[5.1. FCWS Digital signals 21](#__RefHeading___Toc80087252)

[5.1.1. Digital Inputs from subject vehicle sensors
21](#__RefHeading___Toc80087253)

[5.1.2. FCWS digital output 21](#__RefHeading___Toc80087254)

[5.2. FCWS Analog Signals 21](#__RefHeading___Toc80087255)

[5.3. FCWS Sensor interface, parameters and format
22](#__RefHeading___Toc80087258)

[6. SCWS Engineering Computers 22](#__RefHeading___Toc80087259)

[6.1. SCWS Sensor interface, parameters and format
24](#__RefHeading___Toc80087261)

[6.2. SCWS Bus coordinate reference frame and translation
24](#__RefHeading___Toc80087263)

[6.3. SCWS Host Bus Interfaces 25](#__RefHeading___Toc80087265)

[6.3.1. DINEX^TM^ Data (PAT Bus only) 25](#__RefHeading___Toc80087266)

[6.3.2. J1939 / J1708 Data 26](#__RefHeading___Toc80087267)

[6.3.3. SCWS IMU 26](#__RefHeading___Toc80087268)

[7. Video Recorder 27](#__RefHeading___Toc80087269)

[7.1. FCWS Video Recorder Hardware 27](#__RefHeading___Toc80087270)

[7.1.1. Cameras of FCWS 27](#__RefHeading___Toc80087271)

[7.1.2. Synchronization 27](#__RefHeading___Toc80087272)

[7.2. SCWS Video Recorder Hardware 28](#__RefHeading___Toc80087273)

[7.2.1. Cameras of SCWS 28](#__RefHeading___Toc80087274)

[7.2.2. Synchronization 28](#__RefHeading___Toc80087275)

[8. Human-machine interface, parameters and format
29](#__RefHeading___Toc80087276)

[8.1. Warning Levels 29](#__RefHeading___Toc80087277)

[8.2. Hardware Architecture 29](#__RefHeading___Toc80087278)

[8.3. Driver Interface Control Box 30](#__RefHeading___Toc80087279)

[8.4. Driver Vehicle Interface 31](#__RefHeading___Toc80087280)

[8.5. Forward Component 31](#__RefHeading___Toc80087281)

[8.6. Side component 32](#__RefHeading___Toc80087282)

[8.7. Timing 33](#__RefHeading___Toc80087289)

[8.8. Displaying current sensitivity setting
33](#__RefHeading___Toc80087290)

[8.9. Future modifications to this specification
34](#__RefHeading___Toc80087292)

[9. FCWS / SCWS Interface 35](#__RefHeading___Toc80087293)

[9.1. FCWS / SCWS Computer Hardware Interface
35](#__RefHeading___Toc80087294)

[9.2. FCWS / SCWS Computer interface Data Format / Protocol
35](#__RefHeading___Toc80087295)

[9.2.1. Header (Bidirectional) 35](#__RefHeading___Toc80087296)

[9.2.2. Timestamp 35](#__RefHeading___Toc80087297)

[9.2.3. Warning messages (Bidirectional)
35](#__RefHeading___Toc80087298)

[9.2.4. Objects (Bidirectional) 36](#__RefHeading___Toc80087299)

[9.2.5. Curb information (CMU to PATH) 37](#__RefHeading___Toc80087300)

[9.2.6. Sound variables 37](#__RefHeading___Toc80087301)

[9.2.7. Host-bus information: Status 38](#__RefHeading___Toc80087302)

[9.2.8. Checksum 39](#__RefHeading___Toc80087303)

[9.3. FCWS-SCWS Synchronization 40](#__RefHeading___Toc80087304)

Acknowledgements

This report presents the results of a research effort undertaken by the
Carnegie Mellon University Robotics Institute and the University of
California at Berkeley PATH Program under funding provided by the
Federal Transit Administration under Federal ID \# 250969449000. The
direction of Brian Cronin is gratefully acknowledged.

Special thanks are also due to the state transportation agencies for
providing additional funding and contractual assistance. Specifically,
the California Department of Transportation (CalTrans) and the
Pennsylvania Department of Transportation (PennDOT) were instrumental in
the progress of this work.

Also this work would not have been possible without the cooperation of
the local transit agencies. Specifically, the Port Authority of
Allegheny County (PAT) and the San Mateo County Transit District
(Samtrans).

#   {#section .unnumbered}

# Introduction

This document was created for the integrated collision warning system
developed under the joint research program sponsored by a partnership of
California and Pennsylvania teams under the Department of Transportation
Federal Transit Administration Intelligent Vehicle Initiative program.
The purpose of this Interface Control Document (ICD) was to define the
architecture of the Integrated Collision Warning System (ICWS) and the
physical, electrical and electronic interface among different
components.

This is the final document for the installation of the Integrated
Collision Warning System on a transit bus.

# System Architecture

shows the architecture of the Integrated Collision Warning System
(ICWS). The Frontal Collision Warning System (FCWS) and the Side
Collision Warning System (SCWS) are integrated at the higher level. Each
system has its own power adapters, host-bus sensors, obstacle sensors,
video cameras, video combiners, video recorders and engineering
computers. The three engineering computers, which are executing the
warning algorithms, are integrated together through a FCWS-SCWS talk
link. Messages are exchanged through this link. The integrated DVI will
display the warnings from both the FCWS and the SCWS. The two systems
are synchronized offline through the use of time tagged data.

This document describes the interface between the FCWS and the SCWS, and
the interface between the collision warning systems and the host bus.

![](media/image1.wmf)

Figure 1 - System Architecture

For convenience, the following abbreviations are used in the description
of FCWS-related items.

  ----------------- -----------------------------------------------------
  F-                Frontal-looking or frontal

  D-                Driver-side-looking or driver-side

  P-                Passenger-side-looking or passenger-side

  I-                Interior-looking

  LIDAR             Laser scanning radar

  RADAR             Micro-wave radar

  CAM               Camera
  ----------------- -----------------------------------------------------

For example, [F-CAM]{.underline} represents "frontal-looking camera",
and [D-RADAR]{.underline} means "driver-side micro-wave radar".

# Mechanical

## Computer enclosure layouts

![](media/image2.jpeg){width="3.125in"
height="2.3472222222222223in"}Figure 2 shows the layout of the FCWS
computer enclosure of the integrated system on SamTrans bus 601. There
are two PC104 computers (one is the FCWS engineering computer, the other
is the FCWS video recorder), electronics circuits including power
adapters, bus power bars, cable connectors and other circuit boards.

![](media/image3.wmf)

Figure 2 -- Frontal portion of the computer enclosure on the bus (top
view)

Figure 3 shows the layout of the SCWS computer enclosure.

![](media/image4.wmf)![](media/image5.png){width="3.627083333333333in"
height="2.5277777777777777in"}

Figure 3 -- Side portion of the computer enclosure on the bus (top view)

### Electronics power conditioning and power supplies

The master power supplies come from the bus batteries. They are
connected to the 12V/ 24V bus bars by two relays. Power supplies (the
12V/24V bus bars) are located in the computer enclosure. Bypass
capacitors are put on the bus bars to reduce the crosstalk among various
electronics powers.

### Sensor power conditioning and power supplies

All sensor power supplies, except for the driver control input power
supply, which is in the driver box, are from the 12V bus bars, or
provided by power adapters (transformers and converters) inside the
computer enclosure. Bypass capacitors are put at the output of the power
adapters to reduce the power noise.

### Power up and shutdown circuitry

#### FCWS Power up and shutdown circuitry

Two relays control the master power supplies: one is the master relay;
the other is a time-delay relay. After ignition is on/off, the master
relay turns the switch on/off. The switch will trigger the time-delay
relay counter. Once the counter reaches a preset value, the time-delay
relay will turn on/off the 12V and 24V bus bars. The purpose of the
time-delay is to avoid noise-triggered false on/off of power supplies,
and give some additional time to the computers to save files before
exiting the program after the ignition is off. The master relay on/off
signal is sent to the engineering computers to indicate the ignition
operation.

#### SCWS Power up and shutdown Circuitry

Power up time delays and shutdown circuitry is located inside the
computer enclosure.

Power up on the PAT Bus is determined by using a signal that the
DINEX^TM^ outputs to control power to the electronics. This DINEX^TM^
signal is output when the ignition is turned on and the batteries are
being charged. The power down signal is controlled by a time delay relay
which is activated when the ignition is turn off.

Power up / down on the SamTrans Bus is determined by using the ignition
on / off switch through time delay relays.

## Sensor mounting

### FCWS object sensors

Figure 4 shows the layout of FCWS object sensors and video cameras as
well as the SCWS Curb Detector on the front face of SamTrans bus 601.
The positions of each sensor/camera are measured in a FCWS reference
frame. The frame is originated on the ground under the center point of
the frontal bumper with positive directions of x-, y- and z- axes
pointing to driver-side, upward, forward respectively.

![](media/image6.wmf)

Figure 4 Layout of FCWS sensors, cameras, HMI and SCWS curb detector

The numbers that are given in the following tables are the sensor
positions of the FCWS on the SamTrans bus 601 and PAT bus 1560.

  ---------------------- --------------------------------------- ------- --------------
  **Sensor/Parameter**                                                   **Host
                                                                         bus/Value**

  **Description**        **Parameter**                           **Bus   
                                                                 601**   

  F-LIDAR                X (lateral, mm)                         768     

                         Y(vertical to ground, mm)               445     

                         Z(longitudinal to frontal face of the   -25     
                         bumper, mm)                                     

                         Angle ()                                0       

  D-LIDAR                X (lateral, mm)                         1150    

                         Y(vertical to ground, mm)               435     

                         Z(longitudinal to frontal face of the   -38     
                         bumper, mm)                                     

                         Angle ( to the left)                    20      

  P-LIDAR                X (lateral, mm)                         -1180   

                         Y(vertical to ground, mm)               445     

                         Z(longitudinal to frontal face of the   -76     
                         bumper, mm)                                     

                         Angle ( to the right)                   20      

  D-RADAR                X (lateral, mm)                         965     

                         Y(vertical to ground, mm)               445     

                         Z(longitudinal to frontal face of the   -51     
                         bumper, mm)                                     

                         Angle ()                                0       

  P-RADAR                X (lateral, mm)                         -965    

                         Y(vertical to ground, mm)               440     

                         Z(longitudinal to frontal face of the   -51     
                         bumper, mm)                                     

                         Angle ()                                0       

  **Description**        **Parameter**                           **PAT   
                                                                 bus**   

  F- LIDAR               X (lateral, mm)                         820     

                         Y(vertical to ground, mm)               483     

                         Z(longitudinal to frontal face of the   -16     
                         bumper, mm)                                     

                         Angle ()                                0       

  D-RADAR                X (lateral, mm)                         975     

                         Y(vertical to ground, mm)               483     

                         Z(longitudinal to frontal face of the   -48     
                         bumper, mm)                                     

                         Angle ()                                0       

  P-RADAR                X (lateral, mm)                         -950    

                         Y(vertical to ground, mm)               483     

                         Z(longitudinal to frontal face of the   -48     
                         bumper, mm)                                     

                         Angle ()                                0       
  ---------------------- --------------------------------------- ------- --------------

Table 1 - Location and orientation of obstacle detection sensors

![](media/image7.png){width="3.8333333333333335in" height="2.875in"}

The right side of the front bumper below shows the current location of
the FCWS radar and SCWS curb sensors.

### FCWS cameras

+-----------------+-----------------+-----------------+-----------------+
| **Camera**      | **X(m)**        | **Y(m)**        | **Z(m)**        |
|                 |                 |                 |                 |
| **(Bus 601)**   |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| P-CAM           | -0.60           | 2.59            | 0.27            |
+-----------------+-----------------+-----------------+-----------------+
| F-CAM           | 0.93            | 2.69            | -0.13           |
+-----------------+-----------------+-----------------+-----------------+
| D-CAM           | 0.95            | 2.69            | -0.26           |
+-----------------+-----------------+-----------------+-----------------+

Table 2 Camera locations on BUS 601

### 3.2.3 FCWS Host-bus sensors {#fcws-host-bus-sensors .unnumbered}

As to the integrated system on SamTrans bus 601, serial converters for
Lidars are mounted in a waterproof enclosure on the rear surface of the
front bumper. Serial converters for radars are inside the computer
enclosure. Vehicle speed is measured by listening to the vehicle's SAE
J1939 (J1708 on PAT bus) data bus and also by tapping off of an analog
speed signal directly from the transmission. This speed signal from the
transmission is filtered and conditioned by an electronic circuit. The
rate gyro is mounted in a waterproof enclosure on the underside of the
bus floor near the rear axle. Brake pressure is measured using a
pressure transducer mounted on a spare port of the air brake system
under the floor of the driving area. A proximity sensor is mounted near
a universal joint on the drive shaft. This transducer is used to
determine if the bus is moving at speeds lower than 2-3 miles per hour.
Turn signal activation and backing light status is recorded by tapping
off the existing turn signal circuit and backing lights. Windshield
wiper activation is determined with a proximity sensor mounted on the
windshield wiper mechanism. The GPS antenna is mounted on the rear of
roof near the exhaust for the HVAC, the GPS computer is mounted in a
waterproof enclosure near the HVAC evaporator unit in the rear of the
bus. The GPS and CDPD modem antenna are mounted on the rear of roof near
the exhaust for the HVAC, the GPS and CDPD modem computers are mounted
in a waterproof enclosure near the HVAC evaporator unit in the rear of
the bus.

### SCWS Sensor Layout

Figure 5 and Figure 6 show the layout of SCWS object sensors and video
cameras on the right and left sides of the bus. Descriptions of each are
included in the sections below.

Figure 5 - Right Side Collision Warning System Sensor Layout

Figure 6 - Right Side Collision Warning System Sensor Layout

### SCWS object sensors

The SCWS object sensors consist of a SICK laser scanner mounted on the
left and right sides of the transit bus and a curb detector mounted in
the right side of the front bumper. The SICK laser scanners sit
approximately 24 inches above the ground.

The Curb Detector is mounted in the front bumper as shown. Integrating
the Frontal and Side CWS sensors in the front bumper required a layout
that ensured the FCWS Lidars and SCWS Curb Detector would not interfere
with each other mechanically as well as not occlude each other.

![](media/image8.png){width="3.0in" height="4.0in"}

Figure 7 The underside of the front bumper is shown with the laser (blue
arrow).and camera (red arrow) of the curb detector visible

### SCWS cameras

Four video cameras are installed on the transit bus in positions shown
in Figure 5 and Figure 6. The camera mount is shown in the photo below.

![](media/image9.png){width="5.334027777777778in" height="4.0in"}

Figure 8 - Left Side Camera on SamTrans Bus 601

### SCWS Host-bus sensors

The SCWS will tie into the existing electronic infrastructure of the bus
through the J1939 / J1708 interface and the DINEX^TM^ interface when
available. In addition a yaw rate accelerometer is mounted within the
electronics area. The SCWS also duplicates the interfaces to two of the
sensors used for the FCWS. These are the odometry and creep sensors.

## Driver Vehicle Interface

> The main components of the DVI are two LED assemblies -- one on the
> left-hand A-pillar and the other on the center pillar. Both assemblies
> are constructed identically, with 7 LED segments filling the top and 2
> LED segments filling the bottom (see Figure 9)
>
> All LEDs in the displays have the capability to be either amber or red
> (2-color on demand). The forward LEDs are 3 x 2 cm and the rear LEDs
> are 3 x 3 cm with a diamond mask. The total assembly dimension is 4 x
> 22 cm. The positioning of the side LEDs below the forward ones was
> done to match the spatial representation of the driver with respect to
> the threat. In this pattern, the driver "sits" between the bottom
> forward LED and the top side LED diamond. The LED's have a maximum
> luminance intensity of 90/60 mcd and a viewing angle of 100 degrees.
> The display should be covered with a diffusion lens that has a privacy
> coating to reduce passenger observation.

![](media/image10.png)

Figure 9 DVI

## Sensors Field of View

The farthest detectable range for the FCWS in the same lane is 100m
(330ft). The closest detectable range in the same lane is no greater
than 3m (10ft). The maximum detectable side-looking angle from the front
bus corners is 30 degrees on SamTrans bus 601 and 20 degrees on PAT bus.
The detectable lateral position for the forward sensors is over 6m
(20ft). The side looking sensors will closely track objects that are
within 3m of the bus however, objects will be detected as far as 50
meters away. (This whole section is confusing. We should clearly
distinguish between the actual field of view of the sensors and the
areas of interest. We should also state how we come up with the areas of
interest. In the SCWS it is just a good guess and subject to
modification.

![](media/image11.wmf)

![](media/image12.wmf)

Figure 10 Integrated system spatial coverage on SamTrans 601 and PAT bus

## 3.5 Cable routing {#cable-routing .unnumbered}

Cables are run from the computer enclosures to various locations on the
vehicle. Each cable passes through a water tight fitting through the
wall of the enclosures. Each cable is jacketed with plastic split loom
of the appropriate size to protect the cable. Most cables run along the
frame rail, either to the front or rear of the bus. The cable is secured
to the frame/bus via plastic cable ties. Each cable is then either
routed to another enclosure or terminated with a connector.