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A.F.T. AUTONOMOUS FOLLOWER TRANSPORT

John Risch
June 2, 2006

A.F.T
Autonomous Follower Transport Senior Project Report
John Risch jdrisch@hotmail.com Project Advisor: Dr. Alan Felzer Abstract - The objective of this project is to take an
existing remote controlled battery powered transport vehicle and design an autonomous controller to enable the vehicle to follow a navigation beaconon its own.

2. Description
System Block Diagram

1. Introduction
During the process of defining the senior project a simple drawing was created in Solidworks to generalize the packaging and general idea of the project. The car would need a control system, and it seemed natural to place the control box in the front of the vehicle where sensors would need to be placed to seek the navigationbeacon ahead. The navigation beacon would need a source and so a remote navigation module would need to be designed with its own power supply.
Car will autonomously follow Beacon and maintain distance

Control Box

Transport Car

Figure 2.1
Photo Sensor Array
TITLE:

General Statement
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Navigation Beacon
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SIZE DWG. NO.

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TOP
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SCALE: 1:7 WEIGHT:

SHEET 1 OF 1Figure 1.1 Once a clear objective was decided, a plan of action needed to be outlined and organized. By breaking down the objective into a system block diagram, the project could be divided into simple individual objects which could be designed as separate operational modules which in cascade would become the entire control system.

Figure 2.1 shows the top level system block diagram. Theblue box encloses the portion of the system which is to be the senior project, and the grey box contains the components of a remote control operated electric transport car I designed 3 years ago to carry a 25 lb. payload. The upper light green box shows the module of the system that generate the navigation beacon and is located on the person to be followed. The yellow region represents the controlbox that will be added to the front of the transport car. The control box is planned to package the entire control system within a fairly compact rectangular volume as not to take up cargo room or add weight to the vehicle. Each green block represents a module with a specific job to do within the whole control system. The Navigation beacon will be responsible for containing a self powered remotemodule that generates a Infrared or IR pulse signal and can be carried comfortably on a person. The Photo-Sensor array block will contain

the sensors required to read the IR signal from the Navigation beacon and determine an intensity for throttle control and a direction for steering control. The Signal Processing block will contain an FPGA with the appropriate Analog-to-Digital Conversioninterface, Verilog HDL programming to process the signals received by the Photo-Sensor array, and Digital-toAnalog interfacing to control the car’s steering and throttle systems. The car used in this project was designed as a cargo transport specifically to carry a large tackle box used to carry my personal lab equipment for engineering labs. The box I chose to contain my gear was so large and awkwardto carry; it inspired me to design this car to carry the heavy box to class for me. This car has been refined to be extremely efficient and contains Ni-MH power cells with enough extra battery capacity to run the control system and still carry a full-payload all day long on hilly campus terrain. Being able to design a control system without having to design an efficient car chassis and drive trainwas a helpful advantage that allowed me to be more focused on designed the control system. An additional portion of the project involves interfacing an FM transmitter to control the car. This portion is entirely unnecessary in the scope of controlling the cars PWM controlled steering servo and electronic speed control, but is very use specific for my implementation. The car’s job is to carry my...