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Table of Contents
List of Figures .................................................................................................................... iii
List of Tables ..................................................................................................................... iv
List of Definitions2
Introductory Materials ........................................................................................................ 2
Abstract ........................................................................................................................... 2
Acknowledgement .......................................................................................................... 3
Problem Statement .......................................................................................................... 3
General Problem Statement ........................................................................................ 3
General Solution Approach......................................................................................... 3
Operating Environment................................................................................................... 4
Intended Use ................................................................................................................... 5
Intended Users ............................................................................................................ 5
Intended Uses.............................................................................................................. 6
Assumptions and Limitations ......................................................................................... 6
Assumptions................................................................................................................ 6
Limitations .................................................................................................................. 6
Expected End Product and Other Deliverables............................................................... 7
Proposed Approach and Statement of Work....................................................................... 8
Design Objective............................................................................................................. 9
Functional Requirements ................................................................................................ 9
Design constraints ........................................................................................................... 9
Technical Considerations and Approach: ..................................................................... 10
Testing Requirements: .................................................................................................. 11
Security Considerations: ............................................................................................... 11
Intellectual Property Considerations:............................................................................ 11
Commercialization:....................................................................................................... 11
Possible Risks and Risk Management: ......................................................................... 11
Project Proposed Milestones and Evaluation Criteria: ................................................. 12
Project Tracking Considerations:.................................................................................. 12
Statement of work..13
Estimated Resources and Schedules ................................................................................. 18
Personal Effect Budget ............................................................................................... 198
Financial Requirements .............................................................................................. 189
Other Resource Requirements ...................................................................................... 19
Team Project schedule .................................................................................................. 20
Closing Materials .............................................................................................................. 21
Project Team Information ............................................................................................. 22
Summary ....................................................................................................................... 22 iii
List of Figures
Figure 1: View of inside the bus with transmitter and receiver...3
Figure 2: View of the back of the bus with switch..4
Figure 3: Typical HIRTA Bus.........................................................................................5
Figure 4: Block Diagram.....8
Figure 5: Bus Layout ....................................................................................................17
Figure 6: Gantt Chart.....20 iv
List of Tables
Table 1: Financial Budget ................................................................................................. 18
Table 2: Personal Effort Budget ....................................................................................... 19
Table 3: Other Required Resources .................................................................................. 19 2
List of Definitions
Infrared LED: A diode is the simplest sort of semiconductor device. It is a two-terminal
electronic device that permits current flow predominantly in only one direction. LEDs
produce visible light, but an infrared LED produces infrared light that is invisible to the
human eye.
Transmitter: A transmitter is a device which generated the infrared LED.
Receiver:

A receiver is a device that receives the transmitted infrared. It is the detection
system. The transmitter along with the receiver completes the whole circuit.
Phase sensitive detectors: A detector that gives DC output proportional to the phase
shift between a reference signal and the input signal. It is also known as a synchronous
rectifier, synchronous detector,
or synchronous demodulator.
Introductory Materials
This section will provide the general background, technical problem, operating
environment, and intended user(s) and use(s) of the Bus Passenger/Item detection.
Abstract
Several times during the past year, a young passenger was accidentally left behind on a
bus. Currently, the bus driver manually checking the seats is the only prevention for this
problem. To avoid endangering a child, an easy system has been developed that would
alert the driver that something has been left behind. The goal of the system is to alert the
driver before he exits and locks the bus. To accomplish this, sensors will be installed near
the floor in order to check for anything that was left under the seats. To assure that the
driver still manually checks the entire bus for passengers, a button, located in the back of
the bus, will need to be pressed to prevent an alarm from sounding. After the bus is
turned off these two systems will help assure that any child located above the seat will be
seen by the driver and any child located below the seat will be seen by sensors;
preventing children in the future from being locked aboard buses. This system should be
robust, fairly cheap and should be able to install it in any type of bus. 3
Acknowledgement
The Bus Passenger/Item senior design team would like to acknowledge the client, Heart
of Iowa Regional Transportation Agency (HIRTA), for setting the criteria and general
requirements for this project. Also, the team would like to acknowledge the help and
guidance of our faculty advisor Professor Clive Woods.
The May 2005 senior design group would also like to acknowledge the previous work
done on this project during its first phase by the December 2003 team. That team
designed an optical transmitter and receiver which are being considered for use, all or in
part, in phase 2 of the project.
General Problem Statement
Currently the only assurance that children are not locked aboard a bus at the end of the
day is the policy requiring the driver to visually check the bus at the end of the day.
However, with the current system there is no guarantee that the driver will check the seats
and also it is possible that a child who is under a seat will not even be seen. A system is
needed to assure the driver checks the bus at the end of the day and to assure that all
children will be noticed.
General Solution Approach
The system to check for passengers about the bus will be activated when the bus ignition
is switched from on to off. Immediately following this event sensors located on the floor
of the bus will check under all of the seats for any moderately sized object as shown in
figure 1. In addition, when the bus is turned off the driver will have a given amount of
time to walk to the back of the bus and push a button located on back wall of the bus as
shown in figure 2. If either an object is located on the floor of the bus or the button on
the back of the bus is not pushed within the given time an alarm will be activated.
Figure: 1 4
Figure 2
Operating Environment
The system must operate aboard a bus which will travel year round in central Iowa. The
system must be able to function appropriately in an environment that could include
moderate amounts of snow, ice, water, dust, and dirt. All equipme