Computer-Controlled Electronic Brake Release System for Drag

Transcription

Computer-Controlled Electronic Brake Release System for Drag
Computer-Controlled Electronic Brake
Release System for Drag Racing Vehicles
May 8, 2006
Team #3
Manuel Trejo Jr.
Robert Payne
Art Trevino
Craig Davis
An electronically controlled brake release system
activated by a green light optical sensor.
Overview
Problem Statement
Design Phase Approach
Literature and Patent Research
Market Analysis
Design Constraints and User Requirements
Engineering Codes and Standards
Design Concepts
Product Specifications
High Level Block Diagram
Major Components
Detailed Design
Implementation and Integration
Major Problems
Comments and Conclusion
Problem Statement
Start time delay and early start are two
critical concerns that can be overcome
by implementing an automatic brake
release system which is activated upon
receiving the green light “go” signal.
Design Phase Approach
Phase 0: Planning and research
Patent research
Standards and regulations research
Requirements and constraints development
Market analysis
Phase I: Detailed design
Optical sensor development
Develop algorithm
Complete circuit schematic using PSpice
Build prototype
Test for functionality and modify design if necessary
Layout using OrCAD
Develop PCB
Populate PCB
Test for functionality and modify if necessary
IR sensor/ RPM counter development
Same process as optical sensor
Design Phase Approach Continued
Develop micro-controller operation
Develop algorithms and source code to:
Count RPM
Calculate speed
Calculate distance traveled
Calculate distance remaining
Communicate with brake system
Communicate with engine cutoff trigger
Display data on LCD’s
Phase II: Prototype development
Install components and connect to micro-controller
Test for functionality
Debug code
Perform final system modifications
Final test
Assemble documentation package
Total project time: 179 days
Literature and Patent Research
No Computer-Controlled Electronic Brake
Release System Exists
Similar Concepts Have Been Developed
Transmission brake release apparatus
Market Analysis
$1.7 billion annually*
Patent protection and competition
Market domination
*Performance Racing Industry Magazine, 2001 Market Demographics
Global Design Constraints
Engineering Standards
ANSI, IEEE, ASME
Environment
Future PCB (printed circuit board) will meet ROHS compliance
Sustainability
Long-term sales: product reliability will reduce the number of units needed
Plan to offset the reduction from new GUI product version upgrade
Ethical
National Hot Rod Association (NHRA) rules, no ethical issues exist currently
Safety and Health Standards
OSHA: no health or safety issues
Society
No effect on society: used by race car drivers only
Political
No political issues from the product
Liability
Manual disabling could cause malfunctions with minimal liability
No infringements on similar ideas or patents
Local Design Constraints
Cost
Definite constraint until sales start offset cost
Scheduling
Efficiency through good management of supplies, transportation
and weather
Manufacturability
Local constraint due to anticipated volume
Engineering Codes and Standards
Complied with local government regulations
Ethical
No ethical issues on local front
Legal
No infringement on similar ideas or patents, covered previously
by other members during a patent research
User Requirements
System shall not alter vehicle performance
Optical sensor shall be able to receive a green
light signal from 10-20 feet away
System shall be compact an unobtrusive
System shall be weather proof
System shall be shock proof
System shall have an override feature
System shall operate from 12VDC source
System shall be easy to operate
Engineering Codes and Standards
IEC Std 61131-2
IEC Programmable ControllersEquipment Requirements and Tests
IEEE Std C82.38-1994
IEEE Guide on Electrostatic Discharge
IEEE Std 1100-1999
IEEE Recommended Practice for Powering
and Grounding Electronic Equipment
IEEE Std 518-1982
Guide for Minimizing External Electrical
Noise Inputs to Controllers
OSHA Std 1910
OSHA Standard for Electrical Equipment
Design Concepts
Concept #1: Gas powered go-cart
Concept #2: Electric motor with wheel
and axle
Concept #3: Ford Mustang
Design Concept #1
This design concept required the product
to be implemented on a go-cart. A 24V
electromagnetic brake would serve as the
primary braking mechanism. The vehicle
would require rear-axle modifications to fit
the electromagnetic brake assembly as
well as the RPM encoder.
Design Concept #2
This design concept is the simplest of the
three. It requires an electric motor with a
small wheel axle to simulate the braking
mechanism. The electronic circuit will
drive the electric motor when the green
light is activated. The only specific
requirement or modification is for the
microcontroller to deliver enough power to
drive the motor.
Design Concept #3
This final design concept best incorporates
the final product as it would be used in
competition. The system will be
implemented on a Ford Mustang with an
automatic transmission brake system.
Pugh Matrix
Product Specifications
12V DC Battery Operated
Maximum 15’ range for optical sensor
Directional up to 15 degrees of field of view
5V Digital Logic I/O Signals
User friendly hardware interface
System Arm/Reset capability
Manual override
Multiple microcontroller I/O ports
RS232 connectivity
BASIC programming language
Quick-disconnect electrical connections
Temperature resistant
High Level Block Diagram
Flow Chart
Major Components
Control Panel
Easy-to-use user interface
Features ON/OFF, ARM/RESET, override switches, status
indicator LEDs, LCD, and speed control
Electric Motor & Encoder
Power antenna motor used to simulate transmission
brake release interface
Crank shaft angle sensor used for I/R encoder assembly
Microcontroller
Manage all incoming and outgoing signals
Receives green light signal, outputs 5V signal to relay
OOPIC-R microcontroller used due to availability, cost, popularity
and interfacing
Initially the MSP-430 was eliminated because of high cost and
complexity
Detailed Design
(Hardware)
Amplifier/Comparator Circuit Cont.
Voltage Output for Sunny Conditions
Voltage Output For Overcast Conditions
800
700
y = 1.2137x + 118
700
716
720
685
690
y = 1.19231x + 300
600
568
600
595
564
560
606
580
598
575
592
606
582
546
528
Ouput Voltage (mV)
Voltage Output (mV)
y = 1.1593x + 115
500
400
370
350
340
380
355
370
352
333
300
243
235
241
231
200
118
496
468
449
458
435
424
400
393
373
300
333
313
319
298
300
284
536
549
610
600
590
580
570
560
519
504
465
y = 1.13846x + 284
398
358
338
200
Green Light Vout (mV)
Yellow Light Vout (mV)
Green Light Vout (mV)
115
100
500
512
491
581
100
Yellow Light Vout (mV)
0
100
195
195
295
298
300
400
482
484
490
495
500
590
0
596
250
264
276
296
320
357
385
Base Voltage (mV)
396
412
426
438
453
468
471
480
500
Base Voltage (mV)
Voltage Output (mV) for Indoor Lighting Conditions
Output Voltages Under Low Light Conditions
700
y = 1.20455x + 496
700
y = 1.16783x + 476
510
476
431
400
524
451
528
453
526
456
545
569
569
579
579
582
588
487
497
496
508
512
486
544
516
465
600
458
466
514
605
528
610
530
631
545
628
545
639
643
562
567
406
300
Green Light Vout
Yellow Light Vout
612
496
447
508
519
456
565
526
490
466
552
501
510
537
523
546
50
0
49
0
47
2
46
4
45
0
43
9
42
7
41
1
40
6
39
9
572
581
595
y = 1.12121x + 447
400
300
200
Green Light Vout
Yellow Light Vout
Linear (Yellow Light Vout)
Linear (Green Light Vout)
100
Base Voltage (mV)
560
655
623
475
100
0
618
582
546
500
y = 1.12587x + 406
200
600
Voltage Output (mV)
500
35
7
Output Voltage (mV)
600
642
600
0
393
404
411
425
433
440
451
461
473
Baseline Volatge (mV)
480
492
500
512
525
510
Detailed Design
(Software)
OOPic R uses object oriented programming
Develop basic programs
BASIC chosen for simplicity of use
Virtual circuit created for solenoid output
Subroutines for time delay, timer and LCD
readout
Integration and Implementation
Hardware
Hardware
Input
Output
Δt
Delay observed at local IHRA event
Tested system delay
Successful results
Tested with 1Hz/5V input square wave signal
4.8 ms delay measured from input to output
Major Problems
Software
Running nested loops resulted in longer running time of code
execution
Displaying multiple sets of information on the display
Delaying the brake for 10 seconds without delaying the code
Using the real time clock string data as integers
Parsing the data from the code
Truncation of numbers
Hardware
LDR’s susceptibility to heat damage
IC adaptor mounts installed in reverse
Design flaw in placement of power switch
Insufficient current to activate the relay
Comments and Conclusion
Improve optical sensor with more complex optical lens array
Increase field of view
Increase sensitivity
Automatic ambient light detection
Use digital image processing for optical sensors
Use multiple microprocessors to handle various tasks simultaneously
Re-design for efficiency and performance
Design for hands-free user interfacing (i.e., voice commands)
Summary
Problem Statement
Design Phase Approach
Literature and Patent Research
Market Analysis
Design Constraints and User Requirements
Engineering Codes and Standards
Design Concepts
Product Specifications
High Level Block Diagram
Major Components
Detailed Design
Implementation and Integration
Major Problems
Comments and Conclusion
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