Passenger/Item Detection System for Vehicles

Dec03-05 members• Jason Adams

• Ryan Anderson

• Jason Bogh

• Brett Sternberg

Acknowledgements• Clive Woods – Advisor

• Heart of Iowa Regional Transportation Agency (HIRTA) - Client

Presentation Outline

• Problem Statement

• Objectives &

Constraints

• Accomplishments

• Technical Approach

• System Design

• Implementation &

Testing

• Costs

• Projected Dates

Problem Statement

• Prevent passengers from being locked on the bus.

• Need for automatic detection system

Detection System Process• Function automatically

• Accurately detect passenger

• Alert bus driver of passenger

Generalized Project Criteria• Versatile with other bus models

• Robust

• Self-diagnostic

• Fail safe

• Moderate in cost

Passenger Detection System

The passenger detection system is divided into two parts:

• Floor

o Optoelectronics

• Seats

o Pressure Sensors

Operating Environment• Transient bus

• Vibrations

- Bus’s engine

- Roadways traveled

• Environmental elements

- Dust

- Dirt

- Moisture

• Normal temperatures

• Withstand pressure given off by passengers

Intended Users/Uses

Users• male or female adult• commercial driver’s license• no discrimination on the basis of sex, ethnic background, physical

size, or disability• able to operate the commercial vehicle according to the laws of the

state.

Uses• automatically detect remaining passengers and possible items • alarm driver of the situation before he or she has fully exited the bus.

Assumptions• Will be used on a transient bus

• Occupancy ranges from one to seventy-five passengers

• System off while bus is running

• System starts when bus shuts off

• Automatic

• Versatile

• Pressure sensors cover all seats

• LED’s attenuation is eight to ten feet

• Photodiode sensitive to LED only

Limitations• Cost not to exceed two hundred fifty dollars

• Power for the system comes from bus’s battery

• Structure of the bus

• Response time

• Self-operational

• Operating environment

• Spectrum of LED

End Product and Other Deliverables

• Passenger detection system– Seat pressure system– Floor optical system

• Installation directions

• Technical specifications for parts

• End product design report– Cost analysis report

Objectives/ Constraints

Design Objectives Self-automated – Develop a solution that starts up and shuts off

without the interaction of the bus driver.

Energy efficient – Develop a solution that ideally requires no other power source besides the bus battery.

Thorough visibility – Develop a solution that can thoroughly check every part of the bus for passenger(s) or item(s).

Speedy detection – Develop a solution that alerts the driver of passenger(s) or item(s) before he/she is off the bus.

Fail-safe – Develop a solution that will always gets the drivers attention as to alert of onboard passenger(s) or item(s).

Functional Objectives• Passenger warning system – System will warn the bus driver of still

onboard passenger(s) when the bus is shut off.

• Item warning system – System will warn the bus driver of still onboard item(s), at least as large as a small purse, when the bus is shut off.

• Automatic power-on and power-off – System will start automatically upon bus turning off and then shutdown when the bus is started.

Design Constraints Physical properties – System should not be restrictive, distracting, or

discomforting to the driver and passengers.

Size – System should not interfere with normal bus operations. Fail-safe – System should never neglect to alert if a passenger is

present when the bus is shut off.

Power consumption – Power from the system must come from a 12-volt battery.

Response time – System will need to respond within 3-7 seconds of the bus being shut off.

Design Constraints Cont’d• Robust – System may be exposed to the elements and anything tracked

on by passengers such as: rain, snow, mud, dust, and dirt.

• Flexible – Design implementation must be supported for several bus designs.

• Cost effective – If system cost is over $100, some type of funding must be provided.

Present Accomplishments

• Technical Research Completed (95%)

• Determined Technologies Used

• Presented to HIRTA

• In Process of Ordering Parts

Technical Approach• Light Sensitive Resistors

• Pyrometers

• Ultra-sonic signature

• Pressure sensors

• Optical counters

• Magnetic counters

• Infrared LED (emitter)

• Photodiode (detector)

• Weight Systems

• Piezoelectric sensors

• Analog alarm system

• Digital display system

Technical Approach Results

Hybrid system

• Seats - force sensitive resistors

• Floor - infrared emitters / photodiode detectors

System DesignPart I: Pressure Sensors

Purpose: •To detect a left behind passenger and/or item located on the seats.

Basic Operation:•If pressure is detected on the sensor then an analog signal is output triggering the alarm.

Pressure Sensors

Pressure Sensors

Force Sensitive Resistor Sensors

Wiring

Buzzer Alarm System

Benefits: • Low maintenance• Hidden (Will not alter the aesthetics of the bus)• Easy installation

Pressure Sensors

Drawbacks: • More expensive than optics• More difficult to replace

Pressure Sensors

System DesignPart II: Optics

OpticsPurpose: •To detect a left behind passenger and/or item located on the floor.•To detect a left behind passengers in a wheelchair

Basic Operation:•Emitted light that is blocked will cause the alarm to be triggered

OpticsGeneral Layout:

Seat WheelDriver

Seat

Seat

Seat

Seat

Seat

Seat

Seat

Seat

Seat

SeatChair

Seat

Emitter

Detector

Ligh

t

Ligh

t

Ligh

t

Optics

• Why Infrared light?

-So the detection system is not mislead by ambient light

-Optical system designed to only recognize infrared light

-To maintain a failsafe detection system

Optics

Benefits: • Low Cost • Small (Will not alter the aesthetics of the bus)• Very low maintenance • System does not impose any health risk

OpticsDrawbacks:• Tampering with may cause issues

Solution: Enclose in box-type structure

-When bus is running does not need to detect. Implement electronic shutter.

Emitter or Detector

Optics

Drawbacks (cont.):• Power consumption

-May drain battery if left on too long

Solution: Implement a timer or delay

-Only need to detect for about a minute or two.

Alarm

• Both the pressure sensors and optics will be able to trigger the alarm

• Alarm in consideration has the following features:-75 dB buzzer-Tone rated at 300 to 500 Hz

• Some other sound levels-Rustle of leaves ---------------> 10 dB-Conversation ---------------> 60 dB-Rock Concert ---------------> 110 dB-Jet Engine ---------------> 130 dB

• Will implement a kill switch viewable to the bus driver

Implementation/Testing

Implementation / Testing

• Assemble prototype

• Test in laboratory setting

• Test on supplied HIRTA bus

Cost Analysis

BUS

TYPE

1

BUS

TYPE

2

BUS

TYPE

3

BUS

TYPE

4

Projected Dates

8/1/2003: Parts Ordered and Received

9/25/2003: Prototype Implemented

10/20/2003: Finish Prototype Testing

10/30/2003: Implement in Bus Environment

12/15/2003: Finished Product

Questions?