Transcript Critical Design Review

GROUP 1
Kamal Ahmad
Francesco Buzzetta
Joshua Dixon
David Snyder
A Workforce Central Florida Funded Project
A Mike Felix Mentored Project
1
The Problem:

Transporting heavy objects over long
distances

Limiting factors
 Physical stress
 Probability of human injury
 Labor costs
2
The Goal:

The goal is to reduce the amount of stress on
the human body
 college students with books and/or electronics
 Major corporations utilizing human
labor
 A passenger traveling in the airport
carrying luggage.
3
The Solution:
To prevent the aforementioned problem, the
use of an autonomous traveling assistant will
be ideal in order to safely transport the user’s
payload in a stress-free manner. This will be
accomplished through the use of the AMP-V.
AMP-V stands for “Autonomous Mobile
Payload Vehicle.”
4
Goals and Objectives of AMP-V:
Follow the user autonomously
 Mobility on various types of terrain
 Avoid obstacles in its path
 Ascend and descend stairs
 Self-sustaining capability
 Transport a payload

5
Specifications of the AMP-V
Specification
Standards
Dimension
25 in. x 25 in. x 22 in.
Range
24 in. from user
Object Detection
18 in.
AMP-V Speed
3 mph
Operational Time
1 hr
AMP-V Weight
≤ 25 lb
Payload Weight
≤ 25 lb
Photovoltaic Solar Panel
40 W
6
Block Diagram
7
Mobility Hardware
8
Chassis

AMP-V Chassis will consist of a
Plexiglas structure and PVC piping
 Visibility of circuitry, structure, motors, etc.

Four main sections
 Payload Bay
 Hardware Bay
 Photovoltaic Mounting
 Tracks and Sprockets
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Chassis
5
3
3
3
3
1
2
4
4
1.
2.
3.
4.
5.
Payload Bay
Hardware Bay
PV Mounting
Tracks/Sprockets
PV Cell
Motor Controls

The motor controls will consist of an
H-Bridge configuration
 Use of BJTs connected to
microcontroller
 Microcontroller programs
motor controls for mobility
of the AMP-V

Motors set in Parallel
 In order to account for equal voltages on
respective sides and retain stability
11
Motor Controls Schematic

Schematic of 3 A H-Bridge
 Note that this is for one side (i.e. left side motors),
so two of these will be required for the AMP-V
12
Motor Controls Actions
F
R
ENOT
Action
0
0
0
Coast
0
0
1
X
0
1
0
Backward
0
1
1
X
1
0
0
Forward
1
0
1
X
1
1
0
Brake
1
1
1
X
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Tracks & Sprockets

Tracks
 3 inches wide, about 116 inches
○ Rubber
○ Provide high ground clearance
○ All-terrain

Sprockets
 Will be used to define a trapezoid-like shape
out of the tracks
○ Motors
○ Hub
14
Accelerometer
Model :
ADXL335
Features:
3-Axis +- 3g
Low power:
350uA
Single-supply
operations:
1.8V to 3.6V
Bandwidths:
0.5Hz to 1600Hz
15
Proximity System
16
Ultrasonic Sensors

SRF05 Ultrasonic Ranger
 5 V, 4 mA
 Total of 4 sensors, one in each cardinal direction
○ Radial area for pinging
 Trigger and Echo pin
 Returns a positive TTL level signal
○ width proportional to distance of the object
17
Object Detection

Sensors can detect up to 5 meters
 beam width of ±55° perpendicular to the surface

Only interested in objects ≥ 6 in. and ≤ 24 in.
 Threshold of 24 in.
○ AMP-V will maintain a 24 in. distance from the user
 Threshold of 18 in.
○ AMP-V will initiate collision avoidance
18
Collision Avoidance

Maneuvers conducted by the AMP-V to avoid
collisions
 The AMP-V’s control systems will decide
necessary movement
○ Decision making
 Execute movements by sending the appropriate
signals to the motor controls
19
Tracking System
20
Tracking System

Infrared technology
 IR transmitter (Beacon)
 Two IR receivers mounted at front left and front
right of the AMP-V
○ Determines orientation of AMP-V in relation to the
beacon
21
Beacon (IR Transmitter)

5V energy source required
 Four 1.5 V Batteries

IR oscillator circuit
 555 Timer: ICM7555
IR LED: TSAL6200
 Circuit allows for IR LED to toggle on and off
at 38 kHz frequency

 IR receivers will detect the 38 kHz IR wave
‘blinking’ and output it to MCU
22
IR Transmitter Schematic
23
IR Receiver

IR Receiver Module
 Vishay TSOP34838
 38 kHz Infrared Measuring Sensor
 Two IR receivers mounted at front left and
front right of the AMP-V

Analog output
 Read from detection angle of the Receiver
24
IR Receiver Schematic
25
Viewing Angle
IR receivers have a half-angle view of ±45°
 Extended visibility

 64.72° from front
 Turning receivers
19.72° in order to
achieve such viewing
angles
26
Microcontroller
27
Microcontroller

MSP-EXP430FR5739
 24MHz
 2.0V - 3.6V
560uA
○ Low power consumption
 32 I/O
○ 14 10-Bit ADC I/O

Devices:
 Ultrasonic sensors – 8 GPIO - I/O
 Infrared receivers – 2 ADC - I
 H-bridges – 6 GPIO - O
 Accelerometer – 3 ADC - I
28
Software
 Sensors
 Object Detection algorithms
 Accelerometer
 Orientation
 Motor
Control
 Collision Avoidance algorithms
 Infrared
Receiving
 PWM
29
Handshake &
Configuration
Turn On AMP-V
Read Analog Outputs
(Infrared)
Signal motors
for movement
Distance
Comparison
== 24in.
Timer (30 secs)
Signal motors
for movement
User ≥ 24 in. or ≤ 24 in.
Orientation
(accelerometer)
Orientation
(accelerometer)
Adjust Direction
(tracks & motors)
Object Detection
(ultrasonic)
No
Object Detected
within 18 in.?
Yes
Collision Avoidance
(mcu, tracks & motors)
30
Self-sustainability
31
Photovoltaic Cells
Solar Panel
Voc
Isc
Dimensions
Weight
Cost
Monocrystalline
21.6 V
3.26 A
24.95 in. x 24.95 in. x 1.25 in.
8.8 lb
$139.99
Polycrystalline
21.6 V
3.2 A
73 in. x 53 in. x 5 in.
13.2 lb
$159.95
Amorphous
20.7 V
3.06 A
33.5 in. x 17.3 in. x 0.098 in.
5.51 lb
$294.75
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Monocrystalline Solar Panel
Photovoltaic Cell Type:
Monocrystalline
Output Power:
50 W
Maximum/Peak Voltage (Vmp):
17.1 V
Open Circuit Voltage (Voc):
21.6 V
Maximum/Peak current (Imp):
2.92 A
Short circuit Current (Isc):
3.26 A
33
Monocrystalline Solar Panel
34
Power Distribution
35
Power Distribution Diagram
36
Batteries
The AMP-V shall use two 12 V batteries
 The batteries shall provide sufficient energy to

 4 Motors
 4 Ultrasonic sensors
 2 Infrared receivers
 Microcontroller
 Accelerometer

The batteries shall be rechargeable and
sustain operation of the vehicle for at least
one hour
37
Battery Requirements
Voltage
Current
Power
Min
Max
Photovoltaic Cells
10V
18V
Battery(2) - 3800mAh
12V
14.5V
Motor (4)
6V
12V
1.5A
9W
18W
IR Receiver (2)
2.5V
5.5V
3mA
0.02W
0.03W
5.0V
4mA
0.02W
0.02W
Ultrasonic Sensor(4)
Pmin
2.78A
Pmax
50W
45.6W
MCU
1.8V
3.6V
560uA
1.01uW
2.02mW
Accelerometer
1.8V
3.6V
350uA
0.64mW
1.33mW
36.04 W
72.05 W
TOTAL
(including all items)
38
Battery Specifications
Function
Nickel Metal
hydride (NiMH)
Nickel Cadmium Lithium
Rechargeable
(NiCad)
Ion (Li-ion) Alkaline (R-A)
Voltage
1.25
1.25
1.75
1.5
Charge
Capacity
3800 mAh
700 mAh
400 mAh
3000 mAh
Safety
Needs
No
No
No
Yes
Recharge
Cycles
100’s
100’s
>500
10’s
Charge Rate 1.8 – 3.8 A
~2A
400 mA
N/A
Continuous Good
Use
Performance
Good
Good
Poor
Weight
Light
Medium
Light
Heavy
Cost
Low
Medium
High
High
39
Battery Specifications






Nickel-metal hydride (NiMH)
12VDC 3800 mAh (each)
Discharge rate: 3.8 A – 4.2 A
Charge rate: 1.8 A – 3.8 A
1.3 lb
3.3 in. x 1.3 in. x 2.6 in.
40
Voltage & Charge Regulator

3 Voltage Regulators
 12VDC – Motor Controls
 5VDC – IR Receiver and Ultrasonic Sensors
 3VDC – MCU and Accelerometer

1 Charge Controller
 50W Solar Panel to 24VDC Battery
41
12VDC Voltage Regulator
Powering Motor Controls
PT6656
 Integrated Switching Regulator
 Input Voltage = 9 – 28 Volts
 Output Voltage = 12 Volts
 Output Current = 5 Amps
 Simple Implementation (2 capacitors)

42
12VDC Voltage Regulator
Powering Motor Controls
43
5VDC Voltage Regulator
Powering IR Receivers and Ultrasonic Sensors
PT6653
 Integrated Switching Regulator
 Input Voltage = 9 – 28 V
 Output Voltage = 5 V
 Output Current = 5 A
 Simple Implementation (2 capacitors)

44
5VDC Voltage Regulator
Powering IR Receiver and Ultrasonic Sensors
45
3VDC Voltage Regulator
Powering MCU and Accelerometer
PT6651
 Integrated Switching Regulator
 Input Voltage = 9 – 28 V
 Output Voltage = 3.3V
 Output Current = 5A
 Simple Implementation (2 capacitors)
 Additional 35.4 kΩ Resistor on Voltage
Adjustment pin to reduce Vo to 3V

46
3VDC Voltage Regulator
Powering MCU and Accelerometer
47
Charge Controller
48
Administrative
Information
49
Budget & Financing
Part Type
Ultrasonic Sensor
Photovoltaic Cells
Battery
Motors
Tracks
Track Sprockets
Charge Controller
Connectors
Power Converters
Passive Hub Extenders
Cost
$121.56
$149.99
$91.76
$87.80
$233.70
$79.60
$25.00
$50.00
$20.00
$59.80
Part Type
Hub – (motor to sprocket)
Track Fasteners
Motor Mounts
Plexiglas
Overhead
PCB
Infrared Receivers
Infrared Diodes
Accelerometer
Cost
$16.00
$3.95
$29.90
$174.88
$200.00
$200.00
$37.99
$5.00
$32.94
TOTAL : $1,619.87
Final Workforce Central Florida Budgeting $1,927.98
$308.11 under budget
50
Milestone
November 21st – Research Phase
 December 5th – End Preliminary Design
 February 10th – End Prototype Assembly
 February 29th – End Prototype Bugs Phase
 March 31st – End Testing Phase
 April 9th – Final Paper and Presentation

51
Work Distribution
52
Work Completed
53
Work To Be Completed


Ordering Parts
PCB Fabrication and Mounting
 Voltage Regulators
 IR Receivers and Transmitter
 Motor Controls

Assembly
 Chassis
 Tracks
 IR Receiver and Transmitter


MCU Programming, Device Interfacing
Testing
Current Issues

Detecting stairs
55
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