Transcript The Surveyor - University of Colorado Boulder

The Surveyor
By:
Randy Direen, David Cox, Ali Abali,
Leonardo Carrasco, Lisa Prince
Preliminary Design Review
January 25, 2005
Objectives & Purpose
The objective of our project is to build a mobile
robot capable of mapping out its surroundings
using ultrasonic vision and displaying this map
on a computer display. The purpose of such a
machine would be the first step in developing
a robot that could intelligently “learn” its
environment and use what it has learned to
make decisions for navigation.
Base Objectives
 Mobile unit using 2 motors driving 2 wheels
 Map out immediate surroundings using
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ultrasonics
Display the map on laptop / computer
Based on the map make intelligent decision for
navigation
Communicate w/ remote computer using RS232 serial communication (possibly RF control)
2 modes of control - autonomous and manual
control for moving in places of interest
Components: Outline of Approach
 Processor:
microcontroller,
microprocessor,
 Sensor and Scanner:
receivers, transmitter,
oscillator, dual A/D,
FPGA
 Motors: stepper
motors
 Power: battery
Processor: Outline of Approach
Sensors & Scanner Unit
Trans
parent
Latch
Microcontroller
LCD
Flash
ROM
FPGA
(Decode
Logic)
SRAM
Flash
ROM
Microprocessor
Motors
Decoder
SRAM
Processor: Implementation
• Microcontroller:
 Motorola 68HC11 microcontroller
• provides an internal serial interface.
• Real time interrupt circuit.
• Variable baud rates.
 Transparent Latch
• Latches the address of the lower 8 multiplexed address / data
bits.
 Flash ROM
• contains the start up code for the microcontroller.
 SRAM
• contains the firmware required by peripheral devices
controlled by the controller, and the program software.
Processor: Implementation
• Microprocessor:
 Motorola 68000 microprocessor
• 32 bit registers for fast computations.
• 24 bit address bus with capability of addressing up to 16 Mbytes
of memory.
 Flash ROM
• contains the start up code for the microprocessor.
 SRAM
• contains the program software and data points for mapping.
• FPGA:
 Spartan 3
• Provide the memory mapping decode logic for the
microcontroller.
• LCD:
 Alphanumeric LCD controller
• Displays the distance received from the sensor unit.
Processor: Secondary Approach
Serial
Interface
Ultrasonic Mapping Unit
Microprocessor
Flash
ROM
FPGA
(Decode
Logic)
Motors
SRAM
Sensors & Scanners: Outline of
Approach
Amp
Amp
Filter
Amp
Filter
Switch
Oscillator
A/D
FPGA
(Decode
Logic)
RS232
Sensor & Scanner: Outline of Approach
 Recievers: two of them on either side of the transmitter.
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For modularity they will be on their own separate
boards—making testing easy. Before the signal is fed
into the A/D it will be amplified and filtered.
Transmitter: also its own module for ease of testing. It
will have a preamp before the transducer and a switch
before that for modulating a pulse.
Oscillator: around 200KHz source for the modulated
pulse, this will be fed into the transmitter.
Dual A/D: this device will sample both incoming signals
simultaneously.
FPGA: to do signal processing on the two incoming
signals (such as an autocorrelation).
Sensor & Scanner: Implementation
 Reciever parts and Implementation
 Narrow band ultrasonic transducers such as the E188/215.
 Low noise operational amplifiers.
 Butterworth low pass filters.
These receivers will be on separate boards which will
eventually clip onto the scanner. Initially we will use wire
wrapped boards for testing, however, we intend to put
these on printed circuit boards in the future because of
anticipated noise issues.
Sensor & Scanner: Implementation
 Transmitter parts and Implementation
 Narrow band ultrasonic transducers such as the E188/215.
 Low noise operational amplifiers.
 MOSFET or other device for switching.
Transmitter will also be on its own board for testing and
eventually placed on a printed circuit board for reducing
noise.
Sensor & Scanner: Implementation
 Dual A/D
 This will be for sampling the signals from the two
receivers simultaneously.
 FPGA
 Spartan 3
This could also be the TI DSP if we can find the support.
Motors: Outline of Approach
Motors: Implementation
 Stepper Motors
 2 stepper motors used for motion of the Surveyor
 2 controllers that will receive data from the
microcontroller to manipulate the rotation of the
motors. This in turn will control the direction of
motion.
The motors will be implemented on a 3 wheel base. The
2 motors control direction of motion and the 3rd wheel
provides stability and rotational freedom for the robot.
Power: Implementation
 Power Source
 24 Volt Lithium battery.
 Power converters to step down voltage to 3.3 V and 5
V levels.
 24 V supply required to drive the stepper motors.
 Lithium battery allows for recharge ability.
 A cooling fan for preventing overheating of the
internal components.
Division of Responsibility
 Processor, Firmware, and Software
Ali & Lisa
 Sensors and Scanner
Randy & Leo
 Motor and Power
David, Leo, & Lisa
Schedule of Tasks
Outside Resources To Be Utilized
 Aaron Prince
 Maintenance & Project Manager, Koppers Industries,
Denver CO
• Aaron is advising us on the Mechanical design of the
Surveyor and the implementation of motors.
Risks
 Parts availability may cause delays
 Orders can take up to 4 weeks for delivery
 Unforeseen failures
 Burned parts, unavailable parts, non-practical design
Questions?