Transcript Industrial Review Board Presentation

Passenger/Item Detection System
for Vehicles
Dec03-05 members
•
•
•
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Jason Adams
Ryan Anderson
Jason Bogh
Brett Sternberg
Acknowledgements
• Clive Woods – Advisor
• Heart of Iowa Regional Transportation Agency
(HIRTA) – Client
Presentation Outline
• Introductory Materials
• Assumptions & Limitations
• Accomplishments
• Technical Approach
• System Design
• Implementation & Testing
• Resources & Schedules
• Closing
Problem Statement
• Need to prevent passengers from remaining on the bus
after the driver leaves the bus.
• Need for automatic detection system
- Rectifies problem of driver not checking the bus
General Solution-Approach Statement
• Develop initial design
• Present design to client for approval
• Order parts
• Assemble prototype circuits
• Test prototype circuits
• Combine circuits into complete detection system
• Test detection system
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 ten 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
• Technical specifications for parts
• Installation directions
• End product design report
– Cost analysis report
Present Accomplishments
• Defined problem
• Determined possible technologies
• Researched possible technologies
• Eliminated non-feasible technologies
• Designed initial circuit designs
• Presented design to HIRTA
• Ordered Parts
• Produced prototype circuits
• Lab tested prototype circuits
Technical Approach
• Light sensitive resistors
• Photodiode (detector)
• Pyrometers
• Weight systems
• Ultra-sonic signature
• Piezoelectric sensors
• Pressure sensitive resistors
• Magnetic counters
• Optical counters
• Infrared LED (emitter)
Alarm System Approaches
• Analog alarm system
• Digital display system
Technical Approach Results
Hybrid system
• Seats - pressure sensitive resistors
• Floor - infrared emitters / photodiode detectors
Research Activities
• Phase detection
- Remove overlapped signals of unwanted emitters
- Synchronous detection methods allow detectors to accept
only wanted signals
• Seat weight distribution
- Distribute weight located anywhere on a seat to the force
sensor
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 12volt 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.
System Design
Part I: Pressure Sensors
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.
Bus Schematic – Pressure Sensors
Force Sensitive Resistor Sensors
Wiring
Buzzer Alarm System
Pressure Sensing Circuit
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Force-to-voltage circuit
Rf sets sensitivity of circuit
Signaling voltage pre-determined according to Rf
Output will signal parallelizing circuit to trigger
alarm
Pressure Sensor Implementation
• Initial force-to-voltage circuit design
– Removed negative voltage from op-amp
– Altered input voltage to incorporate bus battery voltage
• Short range of linear output voltage
– Set alarm trigger voltage within the linear range
• Size of sensing surface area small
– Install a surface to distribute weight from anywhere on
the seat to the sensing area
Pressure Sensor Testing
• Testing output voltage of force-to-voltage circuit (lab)
– Variable pressure sensor sensitivities (1 lb, 25 lb, 100 lb)
– Variable input voltages
– Variable Rf resistance
•
• Largest S occurred with 100 lb sensor and Rs = 100 kΩ
– Voltage difference = 3 V
System Design
Part II: Optics
Optics
Purpose:
•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
Optics
General Layout:
Seat
Seat
Seat
Driver
Seat
Light
Light
Seat
Wheel
Chair
Light
Seat
Seat
Seat
Seat
Seat
Seat
Seat
Optics
General Layout:
Exhibit A
Exhibit B
Exhibit A demonstrates a much more efficient configuration
among the emitter and detectors!
Optics
Why Infrared light?
• To prevent interference from ambient light
• Optical receiver designed to only recognize infrared light
(tinted photodiode)
• 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
Optics
Drawbacks:
• Tampering with may cause issues
Solution:
-Enclose in box-type structure
-Sheet of plexy-glass over aperture
Emitter or
Detector
Optics
Transmitter
BUS
BATTERY
12 V
VOLTAGE
REGULATOR
5V
OSCILLATOR
SINE WAVE
30 KHz
INFRARED EMITTER
50-50 SPACED
D-FLIP FLOP
SQUARE WAVE
SWITCH
TRANSISTOR (BJT)
INFARED
LIGHT
Optics
Receiver
INFRARED DETECTOR
AMPLIFIER
AMPLIFIER
AMPLIFIER
DIODE
TRANSISTOR
(BJT)
TRANSISTOR
(BJT)
TRANSISTOR
(BJT)
PHASE DETECTION
CIRCUIT
ALARM
Optics
Phase Detection (in phase)
Optics
Phase Detection (90˚ out of phase)
Alarm
• Both the pressure sensors and optics will be able to trigger
the alarm
• Alarm in consideration has the following features:
-90 dB buzzer
• Some other sound levels
-Conversation
---------------> 60 dB
-Rock Concert
---------------> 110 dB
Cost Analysis
Personal Effort
Personnel Name
Adams, Jason
Anderson, Ryan
Bogh, Jason
Sternberg, Brett
Total Hours
165
140
140
160
Personal Effort (Total of 605 Hours)
Ryan Anderson
140 Hours
23%
Brett Sternberg\
160 Hours
26%
Adams, Jason
Anderson, Ryan
Bogh, Jason
Sternberg, Brett
Jason Bogh
140 Hours
23%
Jason Adams
165 Hours
28%
Item
1- 75dB Piezo Electric Buzzer
3- Infared LED pk/3
7- 5 kohm resistor pk/5
7- 0.1uF Capacitor pk/5
7- LM339 Comparator
14- LM741CN Operational Amplifier
14- 1 kohm resistor pk/5
7- Photodiodes
8- Circuit Chip & Wiring
10- Flexiforce Pressure Sensor
Total
Other
Resources’
Cost
Cost
$2.99
$3.00
$6.23
$6.93
$6.93
$12.46
$12.46
$21.00
$40.00
$100.00
$212.00
Other Resources' Cost
$100.00
10- Flexiforce Pressure Sensor
$40.00
8- Circuit Chip & Wiring
$21.00
7- Photodiodes
14- 1 kohm resistor pk/5
$12.46
14- LM741CN Operational Amplifier
$12.46
7- LM339 Comparator
$6.93
7- 0.1uF Capacitor pk/5
$6.93
7- 5 kohm resistor pk/5
$6.23
3- Infared LED pk/3
$3.00
1- 75dB Piezo Electric Buzzer
$2.99
$0.00
$20.00
$40.00
$60.00
$80.00
$100.00
$120.00
Final Projected Costs
Final Project Cost ($6262.00)
$7,000.00
$6,262.00
$6,000.00
Cost
$5,000.00
$4,000.00
$3,000.00
$2,000.00
$1,000.00
$212.00
$0.00
Parts
Labor
Item
Item
Parts and Materials
1- 75dB Piezo Electric Buzzer
3- Infared LED pk/3
7- 5 kohm resistor pk/5
7- 0.1uF Capacitor pk/5
7- LM339 Comparator
14- LM741CN Operational Amplifier
14- 1 kohm resistor pk/5
7- Photodiodes
8- Circuit Chip & Wiring
10- Flexiforce Pressure Sensor
Subtotal
Labor at $10.00 per hour:
a. Adams, Jason
b. Anderson, Ryan
c. Bogh, Jason
d. Sternberg, Brett
Subtotal
Total
W/O Labor
With Labor
$2.99
$3.00
$6.23
$6.93
$6.93
$12.46
$12.46
$21.00
$40.00
$100.00
$212.00
$2.99
$3.00
$6.23
$6.93
$6.93
$12.46
$12.46
$21.00
$40.00
$100.00
$212.00
$0.00
$212.00
$1,650.00
$1,400.00
$1,400.00
$1,600.00
$6,050.00
$6,262.00
Project
Project Definition
Project Definition (Revised)
Project Definition Completion
Project Definition Completion (Revised)
End User(s) End use(s)
End User(s) End use(s) (Revised)
Constraint Identification
Constraint Identification (Revised)
Technology Considerations
Technology Considerations (Revised)
Identification of Technologies
Identification of Technologies (Revised)
Identification of Criteria
Identification of Criteria (Revised)
Technology Research
Technology Research (Revised)
Technology Selection
Technology Selection (Revised)
End-Product Design
End-Product Design (Revised)
Identification of Requirements
Identification of Requirements (Revised)
Design Process
Design Process (Revised)
Document Design
Document Design (Revised)
Prototype Implementation
Prototype Implementation (Revised)
Identification of Limitations
Identification of Limitations (Revised)
Implementation of Prototype
Implementation of Prototype (Revised)
End-Product Testing
End-Product Testing (Revised)
Test Planning
Test Planning (Revised)
Actual Testing
Actual Testing (Revised)
Results Evaluation
Results Evaluation (Revised)
End-Product Documentation
End-Product Documentation (Revised)
End-user Documentation
End-user Documentation (Revised)
Maintenance Documentation
Maintenance Documentation (Revised)
End-Product Demonstration
End-Product Demonstration (Revised)
Demonstration Planning
Demonstration Planning (Revised)
Faculty Advisor Demonstration
Faculty Advisor Demonstration (Revised)
Industrial Review Panel Demonstration
Industrial Review Panel Demonstration (Revised)
Project Reporting
Project Reporting (Revised)
Project Plan
Project Plan (Revised)
Project Poster
Project Poster (Revised)
Design Report
Design Report (Revised)
Final Report
Final Report (Revised)
Weekly Email Reporting
%
Start
01-Feb-2003
01-Feb-2003
01-Feb-2003
01-Feb-2003
03-Feb-2003
03-Feb-2003
04-Feb-2003
04-Feb-2003
06-Feb-2003
06-Feb-2003
06-Feb-2003
06-Feb-2003
10-Feb-2003
10-Feb-2003
12-Feb-2003
12-Feb-2003
06-Mar-2003
06-Apr-2003
10-Mar-2003
10-Apr-2003
10-Mar-2003
10-Apr-2003
20-Mar-2003
11-Apr-2003
13-Apr-2003
13-Apr-2003
24-Aug-2003
24-Aug-2003
24-Aug-2003
24-Aug-2003
29-Aug-2003
29-Aug-2003
19-Sep-2003
19-Sep-2003
19-Sep-2003
19-Sep-2003
02-Oct-2003
02-Oct-2003
16-Oct-2003
16-Oct-2003
21-Oct-2003
21-Oct-2003
21-Oct-2003
21-Oct-2003
31-Oct-2003
31-Oct-2003
11-Nov-2003
11-Nov-2003
11-Nov-2003
11-Nov-2003
14-Dec-2003
14-Dec-2003
16-Dec-2003
16-Dec-2003
01-Feb-2003
01-Feb-2003
01-Feb-2003
01-Feb-2003
01-Mar-2003
01-Mar-2003
01-Apr-2003
01-Apr-2003
11-Nov-2003
11-Nov-2003
01-Feb-2003
Finish
08-Feb-2003
08-Feb-2003
03-Feb-2003
03-Feb-2003
04-Feb-2003
04-Feb-2003
08-Feb-2003
08-Feb-2003
08-Mar-2003
08-Apr-2003
10-Feb-2003
10-Feb-2003
12-Feb-2003
12-Feb-2003
06-Mar-2003
06-Apr-2003
08-Mar-2003
08-Apr-2003
20-Apr-2003
15-Apr-2003
15-Mar-2003
11-Apr-2003
12-Apr-2003
12-Apr-2003
20-Apr-2003
15-Apr-2003
18-Sep-2003
18-Sep-2003
28-Aug-2003
28-Aug-2003
18-Sep-2003
18-Sep-2003
20-Oct-2003
20-Oct-2003
01-Oct-2003
01-Oct-2003
15-Oct-2003
15-Oct-2003
20-Oct-2003
20-Oct-2003
10-Nov-2003
10-Nov-2003
30-Oct-2003
30-Oct-2003
10-Nov-2003
10-Nov-2003
20-Dec-2003
20-Dec-2003
12-Dec-2003
12-Dec-2003
15-Dec-2003
15-Dec-2003
17-Dec-2003
17-Dec-2003
20-Dec-2003
20-Dec-2003
10-Feb-2003
10-Feb-2003
14-Mar-2003
14-Mar-2003
06-May-2003
15-Apr-2003
20-Dec-2003
20-Dec-2003
20-Dec-2003
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Project Evaluation
Milestone
Percent Completed
Project Definition
100
Technologies Considered
100
Ordering of Prototype Parts
100
Construction of Prototype
100
Testing of Prototype
75
Final System Construction
0
Final System Testing
0
Remove Bugs from Final System
0
Project Total
75
Commercialization
• The cost to produce the product is very difficult to determine
- Each system depends on size of bus or vehicle
- Each system must be installed during construction of
the vehicle
• Potential market for this product is large
- Every large capacity transportation company (bus, airline)
Recommendations for Additional Work
• Detect items in specific locations
• Timer/Delay
• Alarm fully on or off
• Reset/override
• Digital display
Lessons Learned
• Practical and applicable solution
• Time constraints and inability to catch up
• Circuit design
• Research techniques
• Application of engineering skills to real world problems
• Set more strict deadlines
• Documentation
Risk and Risk Management
• Time consumption of learning the technologies used
– Consulting advisor more often than not
• Complete redesign of optoelectronics
– Learn the technology
• Delay in ordering parts
– Ordered parts as soon as possible
• Unavailability of times for the team to meet
– Two smaller teams
• Reliability of the breadboards used in circuitry
– Troubleshoot, troubleshoot
• Receiving wrong parts
– Use replacement parts
– Redesign circuitry
•Small size of the pressure sensing area
– Find a surface to distribute weight to the sensor
Closing Summary
• Passenger detection system
• Hybrid design using two technologies
– Floor space : Optoelectronics
– Seats : Pressure sensors
• Automated
• Eliminates the factors of human error
Questions?