Transcript Preliminary Design Review

BoneCrusher Automation
Floor Art Super Transcriber (F.A.S.T)
Niket Sheth
Chris Karman
Erik Scherbenske
Peter van der Hoop
 Build a robot to reproduce shapes, text or follow user
input paths.
 Robot will use markers to create drawings on the floor.
 Scalable drawings depending on floor size.
 Tethered Control using:
 Joystick
 Keyboard
 Pre-Encoded Instructions
 Touchpad
 Wireless control should eventually replace tethered
line
 Milestone 1
 Moving robot that can be controlled with directional
inputs via USB input
 Milestone 2
 Robot can reproduce shapes and text given a user input.
 Expo++
 Robot is wireless, can use multiple marker colors, has
collision and boundary detection sensors, and can
follow touch pad input drawings.
Marker
Input
CPU
(MSP430)
Sensors
Motor Drivers
(L297, L298A)
 Robot moves with two Sure Step stepper motors that
take inputs from DRV8412 motor drivers
 The DRV8412 is a high performance integrated dual
full bridge motor driver
 Takes 4 out-of-phase inputs to drive the motors
 We have switched from the DRV8412 to the L298N and
L297
 L297 generates 4 outputs from a single clock input to
drive the motors (connected to L298N)
 Operating Supply Voltage up to 50V
 3A max current output
 Operating frequency up to 500kHz
 Integrated self-protection circuits (under voltage, over
temperature, overload, short circuit)
 No external schottky diodes required
 Takes four off-phase step functions as input
 Much simpler two phase bipolar stepper motor driver
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
than the DRV8412
Takes only one step input
46V, 4A max
Over temperature protection
High noise immunity
MSP430
 NEMA-17
 1.8 degrees per full step
 Half-Step Capability
 Holding current up to 1.7 A
 Input
 4 out-of-phase step functions
 1.6 ohms
 Use a stepper motor to rotate markers into place
(PWM).
 MSP430 provides the path to draw
 Multiple color control through the motor PWM.
 Controls rotation of marker wheel
 Spring controlled pressure on markers
 Color change capabilities
 Uses the same motor drivers and stepper motors as the
wheels
Rotate Pen
Down/Up
Motor
 MSP430f1232
 3 PWMs
 Multiple digital I/O
 UART Control
 DAC
 8 MHz
5V Rail
Reset Button
Collision Detection
Collision Detection
Collision Detection
Collision Detection
Motor Reset
Motor 3 Enable
Motor 2 Enable
Motor 1 Enable
Motor 3 PWM
Motor 2 PWM
Motor 1 PWM
Motor 3 Direction
Motor 2 Direction
Motor 1 Direction
PC Connection
PC Connection
 Motor Control
 3 PWMs (Square Waves) – 3 Motors
 Speed – Period of waves
 Distance – Duration of signal
 Marker Control
 Controlled by Marker Wheel attached with Stepper
Motor
 Signal will enable the wheel to rotate until marker in
DOWN position.
 Opto-isolators
 Separate the MSP430 from L298N and L297 in case of
mishaps.
 May need to add transistors for current boosts.
 MSP430 might not be able to apply enough current to
the opto-isolators
 Control of the Direction and Speed will be determined
by code on MSP430
User
Keyboard Input
Joystick Input
Path Generated
Input Basic
Directions
PWM for Each
Wheel
Generated
Trackpad Input
Stop From
Collision
Sensors
Marker Position
Selected
 Collision Detection
 Bumpers that detect collision and send data to CPU
 Infrared that detect objects in path before collision
 Boundary Detection
 Detect predefined physical boundary
 Infrared (black line surrounding “canvas”)
 Using MAX3100, MAX3120 infrared drivers.
 Software boundary
 Max distance allowed for travel from initial starting point
 Turn OFF or correct motion when the sensors detects a
problem.
 3 to 5.5V operating voltage.
 1 CM to 1 M detection range.
 High accuracy (built-in narrow band pass filter).
 Compatible with MAX3100 (IR to UART Data Link).
 Schmitt Trigger input/output operation.
 Power Control Board
 Provide 50V for the stepper motor, 7V for the logic
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circuitry (motor driver), and 2V for the MSP430 CPU
chip.
Isolation circuit using opto-isolators MAX232IN for
providing current to motor.
Power monitoring and reporting controlled by MSP430.
Conservation of power by shutting down components
not being used by controlling the signal to the enable
pin in the motor driver.
Rechargeable battery.
Task
Peter
Erik
Niket
Chris
Mechanical
Chassis/Mounts
X
Electrical
Input Controls
X
Motor Controls
X
X
X
CPU/Power
Management
X
X
Marker/Sensors
X
X
X
X
X
Software
CPU
UI Software
X
X
X
X
Integration
X
X
Manufacturing
X
X
Testing
X
X
X
X
Documentation
X
X
X
X
Item
Quantity Price ($) Purchased?
Mechanical
Chassis/Mounts Material
1X1m
75
Castor Wheels
2
4
yes
Differential Wheels
2
10
Stepper Motors (Sure step)
3
40
yes
Other Mechanical Parts (Screws, Springs, Servos)
50
Electrical
LEDs
10
10
Battery/Circuitry/Controller
150
partially
Battery Charger
1
25
Infrared Sensors (LED, Photo Diodes, MAX3100, MAX3120)
8
180
Bump Sensors
10
5
Microcontrollers (MSP430F1232IPW)/USB interface
50
partially
Motor Drivers (TB6560AHQ, DRV8412, L297, L298, L6210)
50
yes
PCB Printing
130
Other Electronic Parts (Wires, Connectors,etc)
80
partially
Miscellaneous
Markers
5
Presentation/Documentation(Printing, Poster, Binding)
65
Total
929
 Signal/Power Noise
 Opto-Isolators, separate regulators purchased
 Motor Accuracy
 Loose Contacts between wheel and ground – Slowly build up the
speed to avoid loose contact.
 Inaccurate stepping by motor – High current keeps steps accurate
 Power management surges and spikes
 Opto-Isolators
 Lose communication with robot
 Range - Software controlled Power OFF
 Loose wiring – Effective Build Up
 Uncertainty in learning curve
 Uncertainty in parts availability and delivery
 Unfamiliar technology