1	A.C.M.E. Automated Commuter Merging and Exiting Project members: Tim Ring, EE Adam Nelson, EE Scott Bertling, EE Joe Harrill, EE
2	What is ACME? ACME is an automated highway system. An automated highway system autonomously navigates a vehicle to a user defined destination. ACME combines a vehicle and highway with microcontrollers, receivers, transmitters and magnetic sensors. The purpose of this project is to design an automated highway system on a miniature scale that could lead to further research.
3	History of an AHS 1^st presented by General Motors in 1939 at the World’s Fair. During the end of the 1980s, advances in microprocessors, wireless communications and other electronic sensors prompted a renewed interest in the automated highway, leading to the formation of the Intelligent Transportation Society (ITS) of America in 1988. More recently, several pilot tests of automated highway systems are underway and run by the National Automated Highway System Consortium.
4	AHS Diagrams Vehicles travel in “platoons” guided by onboard sensors. Vehicles communicating on lane changes. Exit beacon transmitting data to vehicles.
5	AHS Current Research Two types of navigation. Beginning of AHS implementations.
6	Why is this Important? Roadways are dangerous and increasingly expensive to maintain. Many societies have been very successful at finding creative alternatives to make their transportation systems safer and more efficient. The structure of the automated highway system is a familiar format for the U.S. culture and easily recognizable to its users. Therefore, a new infrastructure will not be needed and only retrofitting current systems will be needed.
7	A.C.M.E’s Project Objectives The vehicle’s guidance system is controlled by a microcontroller and sensor configurations. This system is guided by signals in the roadway. Exit beacon transmitters relay exit information to vehicle. On-Board Receivers receive this information and communicate this to the microcontroller for decision making.
8	ACME Block Diagram User inputs exit # and car follows LHS magnets. Beacon # is tripped when RF car passes roadway sensor. The exit # and beacon data are compared. RF car follows RHS magnets to exit #.
9	Navigation Tim Ring
10	Navigation Four types of technologies were considered for navigation in the project: imaging systems, radar, line-trackers and magnetics. Magnetic systems are the only type that are transferable to the real world. Sensors are not affected by dirt or mud. Magnetic fields on the roadway operate through all environmental issues. Magnets will not degrade over time.
11	Navigation Table
12	The Magnetometer A magnetometer senses the generated magnetic field.
13	The Magnetometer of Choice There are several types of Magnetometers. Our team selected the digital Hall-Effect Sensors which generates a voltage when the current flow is perpendicular to the applied magnetic field.
14	The Hall Effect Sensor We are using the Uni-polar Hall Effect Sensor. Uni-polar meaning activation by one pole. The output is a logic high with no B-Field and a logic low in the presence of a B-field. The turn on strength needed is 35 G. Switching is done by an internal NPN transistor.
15	Hall Effect Sensor Array Schematic
16	Application The left two sensors track the roadway and the right two sensors track the exits. The left side will operate until tripped by the exit beacon. The table applies to the LHS only. RHS table being 10 = Left and 01 = Right.
17	Hall Effect Sensor Array
18	Hall Sensors In Roadway Sensors in the roadway ,triggered by magnets onboard the vehicle, send a logic signal to the vehicle about the upcoming exit.
19	Magnets Very powerful permanent magnets are needed to activate magnetometers. These magnets are Ceramic, Alnico, Samarium and Neodymium. These compounds are mostly found in combination with Iron, Chrome, Boron and Cobalt.
20	Comparison of Magnets
21	Maximum Air Gap for Sensor Operation. Sufficient strength to activate sensor
22	Microcontroller Adam Nelson
23	Microcontroller The brains of the project, every system is tied into the Microcontroller. Microcontroller criteria: Versatile Sufficient in processing power Easy to use Fairly cheap
24	Microcontroller Project Demands A Microcontroller able to process functions simultaneously A Microcontroller that processes fast enough for precision timing and accuracy for tracking.
25	Microcontroller Capabilities Microcontroller criteria Multiple Sensors Two DC Motors RF Receiver Input Devices LCD Parallel Communication Analog Devices
26	System Block Diagram
27	Microcontroller Comparison
28	OOPic Vs Basic Stamp
29	Evaluation Board Two choices Make a board Allows for choosing each component Cheap Time consuming; learning software and hardware, trial and error, ordering parts, soldering, design,…etc. Buy a board Compromise to board configuration Save time (preassembled and tested) Professional layout
30	Evaluation Board OOBOT40 from Oricom Technologies 18 non-dedicated I/O lines 4 H-bridges Up to 7 A/D lines Up to 8 servo lines 3 High current drivers Will run off 6 to 15 volt source
31	The After Math
32	Microcontroller Systems Distribution 1 Analog to Digital I/O Line for potentiometer 6 I/O Lines for Steer and Drive Motor 4 I/O Lines for the Magnetic Sensors 1 I/O Line for serial LCD display 2 I/O Lines for the push button switches 3 I/O Lines for RF Receiver 5 Lines dedicated for power 5 Lines dedicated for ground
33	Programming Three Main Sub procedures Initial input: Corresponds with the user interface via LCD and input device Tracking: Follows the magnetic track linking the magnetic sensors to the steering motor Exiting: Breaks from the primary track to a special exiting lane track.
34	Programming The initial sub procedure links a serial LCD and two push button switches together creating a user interface. The system starts out initially by displaying a message on the LCD screen asking the user for a destination, and will await for an input from the user. The data will be stored in memory and the vehicle will be set into motion.
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36	Flowchart Diagram Input
37	Programming The tracking sub procedure ties the magnetic sensors to the steering motor. A potentiometer along with the sensors gives the vehicle two reference points. When both sensors read true (Logic 00) and the potentiometer is centered, the vehicle will be inline with the magnetic field. The system will work by sensing the logic state of the magnetic sensors; There are four logic states that are used. A change in logic state will trigger an event or interrupt that will subsequently call a subroutine that will correct the path of the vehicle.
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40	Flowchart Steering
41	Programming The exiting sub procedure is much like the tracking sub procedure except that tracking from one set of sensors will switch to another set. In Addition the steering increases for the exiting sub procedure. The Design of this procedure begins with the data entered in from the initial sub procedure. When the vehicle falls within range to the RF signal the data received from the signal will be cross referenced with destination data. NOR logic will be emulated to select the appropriate course of action
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43	Flowchart Exiting
44	A.C.M.E Communications Scott Bertling
45	A.C.M.E. Communication Systems The Communications systems was divided into two major categories. Exit Beacon Transmitter The A.C.M.E. communication system transmits Exit identification data. Vehicle Receiver subsystem. The vehicle detects the transmission and latches the data for an exit match by the microcontroller.
46	What are the A.C.M.E. Communications systems used for? The communications in this system is used to let the vehicle and driver know when they have arrived at a previously selected exit from the highway system. It communicates this information to the main system MCU so that it may select and follow the exit path.
47	Requirements of the RF subsystem. The RF transmitters and receivers must be: Able to transmit and be received at a distance of 40 meters. Be programmable. Simplex data transfer. Be completely portable. Small in physical size. Low power consumption. Interface with the A.C.M.E. system microcontroller. Low Cost.
48	Vehicle Communication System Block Diagram.
49	Building of the data/RF system. The core of the Communication System was determined based on the following considerations: The System transmits an identification code to identify individual beacons. All of the systems exit beacons transmit their specific I.D. codes on the same RF frequency. This allows for the vehicles in the system to be continuously tuned to all of the Beacons in the system. The Beacon transmitter only operates when a vehicle is detected in the range of the transmitter.
50	The ideal way to start. The best way to meet all of the needs and considerations of the communication systems was to start with a RF development kit. These include at least one transmitter and receiver. Development hardware and software. Programmable components.
51	Choosing the RF components.
52	RF Development Kit Kit includes MP lab IDE development environment. Development board, USB to PC interface. Code development in Assembly. Allows for individual component programming or in-circuit-programming of the module. Transmitter Modules are capable of in-circuit-programming. Receiver Modules do not require programming.
53	The RF development KIT
54	Transmitter and Receiver Modules
55	Beacon Housing Enclose Transmitter and Vehicle Detection switch. Small (2.5” x 2.75” x 5.25”) Manufacturer Unknown
56	Beacon to Vehicle Block Diagram
57	Receiver Decode to Interface The data that is transmitted is be demodulated within the Receiver Module. It is now a PWM data stream at base-band. The PWM data is then decoded to a parallel data configuration with the programmed decoding PIC. The output from the decoding PIC will now need to be conditioned for interface with the OOBOT40 microcontroller.
58	Exit Beacon Data Latch The exit data is decoded and latched for the MCU to detect. This allows the MCU to accept the data when it is ready and not interrupt any drive control sequences. Finally, the latched data drives an LED to indicate it’s condition.
59	Communication Beacon/Vehicle Flowchart
60	Receiver Decode to Interface
61	Exit Beacon Data Latch
62	Exit latch logic Logic for exit is latched to the output of the 74F573 data latch when the latch enable line transitions from high to low. Latch enable is triggered by the data and conditioned to go low while data is still high.
63	Communications Interface CCA Communications interface CCA installed on the vehicle.
64	Motor Control Joe Harrill
65	The Vehicle HPI R/C car-Dash Series Existing Vehicle Power 7.2 Volt battery pack Used to power the drive and steering motors through the two H-bridges Additional power 7.2 Volt battery pack to power Micro-controller through 5 volt voltage regulator Communications board
66	Drive Motor The drive motor for the car is a 7.2 Volt electric motor which draws a maximum of 6 Amps at full throttle moving the car at speeds of 30mph. 3 Amps peak for the operation of this project due to the minimal velocity. This current occurs when moving the car from rest. 1 Amp continuous during constant minimal velocity
67	Basic H-Bridge Design
68	SN754410 16 pin H-Bridge IC Manufactured by Texas Instruments 2 Amp max current 1 Amp continuous current Already integrated with the Oobot40 board and the Oopic
69	NIMH-0050 Manufacturer: New Micros 5 Amp continuous current-ample current for the drive motor 6 Amp peak current Designed to be universally compatible with most micro-controllers-works with the same code used to control the SN754410
70	Drive System Block Diagram
71	Steering The steering mechanism is powered by an electric motor that is hooked up a potentiometer that determines the position of the wheels. This motor runs off the SN754410 H-bridges that are on the OObot40 board, the high current H-bridge powers the drive motor. Switching the polarity on the steering motor effectively steers the car in opposite directions. An A-D from the micro-controller takes readings from the potentiometer so that the wheels return to a straight path after steering in either direction.
72	Steering Potentiometer The only way to achieve the “steer straight” function returning the wheels to the centerline is to read off the potentiometer from the original steering mechanism The potentiometer is at 3 Volts when the wheels are aligned center. The far right and left are 0.8 Volts above and below the 3 Volts An A-D converter is used to allow the micro-controller a reference to return the car to a straight path
73	Steering System Block Diagram
74	Exit 1
75	Exit 2
76	Administrative Content
77	Distribution of Work
78	Milestone Chart
79	Project Expenses Vehicle $50.00 Micro-controller $88.00 RF transmitters and receivers $135.00 Rechargeable Battery packs $45.00 2 Serial Cables @ $14.00 each $28.00 OOpic programming book $24.00 Unipolar Hall Effect sensors Freebie Magnets ($0.28 per 1.87”, 26’ total) $50.00 Switches for exit selection $10.00 LCD $53.00 External H-Bridge $30.00 Miscellaneous Components $157.00 Roadway Construction materials $120.00 Vehicle Chassis materials $40.00 __________ Total Expenses $830.00
80	Questions?
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