EE Detailed Design Review

spectacularscarecrowAI and Robotics

Nov 17, 2013 (3 years and 4 months ago)

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EE Detailed Design Review

Kyle Backer

Mike Thomas

Matt DeCapua

Design Review Goals



Review Customer Needs & Specifications




Calculate Power Requirements




Describe In Detail the Power Distribution Throughout the
Robot




Determine External Sensors & Placement on Robot



Update Risks & Concerns



Proposed Bill of Materials

Customer Needs

Customer Need
#

Importance

Description

Comments/Status

CN1

1

Walk

Servo Control Algorithm


CN2

1

Turn


Servo Control Algorithm

CN3

1

Object Avoidance

Sense object In all directions


CN4

2

Get up
-
Forwad fall


Sensor reading and control algorithm

CN5

2

Get up
-
backward fall


Sensor reading and control algorithm

CN6

3

Resist fall


IMU Reading

CN7

2

Voice Activated

Speech Recognition Module


CN8

2

Non
-
Tethered


Battery Powered

CN9

1

Height

Must be at least 2 ft tall, preferably larger

CN10

1

Additional Weight

Accommodate 25% of total body weight

CN11

1

Humanoid Proportions/Limbs

Must look and move like a human

CN12

2

Head Functions

Head needs to potentially move and/or support sensors

CN13

3

Off Shelf Part Sources

Need readily available parts

CN14

1

Adequate Computational Power


Dedicated Robotic Computer

Customer Specifications

Spec. #

Importance

Source

Function


Specification (metric)

Unit of
Measure

Marginal Value

Ideal Value

Comments/Status

S1

3

CN9

F1
-
F4,F7

20"
-
36" tall

inch

28

36



S2

1

CN10

F1
-
F7

Carry 25% of own weight

lbs

5

>5lbs

Weight about 14lbs

S3

2

CN11

F5,F6

DOF per arm

x

4

5

Ignore wrist movement

S4

3

CN11

F1, F2, F3

DOF per leg

x

4

6

6 DOF likely

S5

2

CN11

F4, F1

DOF Torso

x

1

2



S6

3

CN12

F13

Head turn up/down
-
45 degress to 90 degrees

degrees







S7

3

CN12

F13

Head turn 90 degrees left/right

degrees

90

90



S8

2

CN11

F1

torso bends 90 degrees down

degrees

90

>90



S9

2

CN11

F4

Torso turns 45%

degrees

45

90



S10

2

CN11

F1
-
F7

Human proportionality

x

x

x



S11

1

CN13

F1
-
F3, F5

Servos from the market

x







S12

1

CN14

F12

Servo driver from the market w/ extra ports

x







S13

1

CN14

F12

Micro controller/small computer w/ OS

x





Roboard 110

S14

1

CN14

F12

Software Libraries

x







S15

1

CN1

F1
-
F3

Walking

x



Natural



S16

1

CN2

F1
-
F3

Turning

x

Halting

Natural



S17

2

CN4

All

Recovery from forward fall

x







S18

2

CN5

All

Recovery from backwards fall

x





Roll onto front possibly

S19

2

CN6

F9

Resistance to fall

x







S20

1

CN3

F8

Avoid object within 25"

inches

24”

>24”



S21

1

CN3

F8

Turn accordingly to avoid obstacle

x







S22

2

CN4/CN5

F9

sensors to detect fall

x







S23

1

CN6

F9

sensors to detect forces and resist fall

x







S24

1

CN3

F8

detect object in back

x







S25

1

CN3

F8

detect object in front

x







S26

1

CN3

F8

detect object in right/left

x







S27

1

CN11

F1

45 degrees forward bend at waist level

degrees

45

45



S28

2

CN7

F11

16 word voice commands

x

16

>16



Power Calculation

Part Name

Function

Required

Voltage

Quiescent

Current

Active

Current

Power


/ Per

Number

Total

Power

EasyVR
Speech


Module

voice
commands

5V

1mA

180mA

.9W

1

0.9

RoBoard RB
-
110

main

computer/proce
ssor

6
-
24V

400ma

2W

1

2

LV
-
MaxSonar
-
EZ0

ultrasonic
rangefinder

2.5
-
5.5

2mA

.01W

2

0.02

GP2Y0A02YK
0

IR rangefinder

4.5
-
5.5

33mA

0.165

4

0.66

IMU Combo
Board

Internal
Gyro/Accelerom
eter

3.3V

45uA

6.75mA

0.022

1

0.022

RoBoard

RS
-
1270

Servo

7.4

5mA

1.5~5A

11.1~
37W

22

~66

70W

General Power Diagram

7
.
4
V
5000
mAh
Li
-
Poly Batteries
Benchtop
Power Suppy
Automatic
Source
Selection
To
Sensors
M
Servo
Power
Switch
22
x
Servo’s
RoBoard
Computer
System
Fuse
2
-
4
S Li
-
Poly
Low Voltage Alarm
Power Distribution Circuit

Battery Selection


In total Servos Can pull >40A



Robot needs to last 1
-
2 hours



2x 7.4V 5000mAh Li
-
Poly Proposed



Waiting for test results from Team 1

Selected Servos


RoBoard RS
-
1270 digital
servo

motor (x22)


Torque @7.4V: 35.0 kg
-
cm/486.0 oz
-
in


Voltage: 6 to 7.4V


Weight: 70g


Suggested voltage: 7.4V


Current draw max: 5A


Total average current: 6.6A


Expected walking current: 18A

Selected Connectors

Battery and Wall Power >40A

Servo Power max 5A

Proposed PCB

Sensor Placement


4 infrared sensors sensors for short
range detection(Front, back, left, right)


2 ultrasonic sensors for long
range(Front
-
left,front
-
right)


1 accelerometer/gyro
board(Internal:chest)


1 voice recognition
module(Internal:chest)

Wiring Diagram

Updated Risks

ID

Risk Item

Effect

Cause

Likelih
ood

Severi
ty

Import
ance

Action to Minimize Risk

Owner

Describe the risk briefly

What is the effect on any or all of
the project deliverables if the
cause actually happens?

What are the possible
cause(s) of this risk?

L*S

What action(s) will you take (and by when) to
prevent, reduce the impact of, or transfer the risk
of this occurring?

Who is responsible
for following
through on
mitigation?

1

Overheating

System damage, reduced
performance

Continuous servo and battery
use, limited ventilation

2

2

R

Construct an open body, allowing ventilation,
include cooling fans and heat sinks

EE

3

Over budget

Not finishing

Spending too much, expensive
servos

2

3

P

Sparkfun free day, conservative spending, find least
expensive components

All

5

Insufficient battery voltage

Lower servo torque, limited
effectiveness of processor/sensors

not fully charged/Balanced

1

2

P


Use Balancing charger and Low voltage alarm during
operation

EE

6

Insufficient battery capacity

Short operation time

Battery too small, large current
draw

1

1

R

Choose batteries carefully, choose low power
components

EE

7

Insufficient sensor range

Unable to avoid obstacles properly

Sensor range too short

1

1

A

use combination of infrared and ultrasonic

EE

14

Large Current Draw through
Wires/Connectors

Wires/Connectors

Burn/Melt

Excess of current

2

3

P

Cautious selection of wiring gauges

And Molex Connectors

EE

15

Signal corruption

Incorrect Servo Position

Noise affecting PWM signals

2

3

P

Adequate grounding and shielding

EE

16

Power Distribution PCB

Overheats or Shorts

Loss of Power, Servo Damage

Too small traces

2

3

P

Make traces as wide as possible

EE

17

All Servos Lock Up

Max current draw, Damage to
power componets

Awkward movement,
programming errors, sensor
errors

2

3

P

Use a 60A fuse

EE

P12202 Humanoid Platform

Bill of Materials

Part Name

Manufacturer

Manufacturer Part #

Distributor

Distributor Part #

Web Location

Quantity Needed

Unit Price

Total Price

Status

Comments

Electrical

5000mAh 7.4V

Li
-
Poly Battery

Spec Point

Concepts

N/A

Spec Point

Concepts

N/A

http://www.specpoint

batteries.com/index.php?productID=59

2

$28.95

$57.90

In

stock

Batteries

2S~4S Li
-
Poly

Low Voltage Alarm

N/A

N/A

All Battery

N/A

http://www.all
-
battery

.com/VoltCheckerandLowVoltBuzzerfor1
-
7SLipo_Li
-
ion_NiMH_LiFe
-
52025.aspx

2

$4.99

$9.98

In

stock

Battery

Protection

Traxxas Male

Connector

N/A

N/A

All Battery

80027

http://www.all
-
battery

.com/traxxastrxmaleconnector
-
chargertruckside.aspx

2

$3.99

$7.98

In

stock

Female

Connector

for Battery

Molex PCB Power

Connector (Mini
-
fit Sr)

Molex

428192232

Digi
-
Key

WM4431
-
ND

http://search.digikey

.com/us/en/products/0428192232/WM4431
-
ND/2421502

3

$2.99

$8.97

In

stock

PCB connecter

for external supply

and batteries

Molex Vertical Power

Connector (mini
-
fit sr)

Molex

42816
-
0212

Digi
-
Key

WM1927
-
ND

http://search.digikey

.com/us/en/products/42816
-
0212/WM1927
-
ND/283471

3

$1.48

$4.44

In

stock

mates with

PCB recepticle

Mini
-
Fit Sr Male

Crimp Connection

Molex

428170131

Digi
-
Key

WM3194CT
-
ND

http://search.digikey

.com/us/en/products/0428170131/WM3194CT
-
ND/2405670

6

$0.84

$5.04

In

stock

crimpable

connector

contacts

Mini
-
Fit Sr Female

Crimp Connection

Molex

42815
-
0032
-
C

Digi
-
Key

WM1949
-
ND

http://search.digikey

.com/us/en/products/42815
-
0032
-
C/WM1949
-
ND/513214

6

$1.05

$6.30

In

stock

crimpable

connector

contacts

Mini
-
Fit Jr PCB

Header

Molex

39
-
28
-
8020

Digi
-
Key

WM23800
-
ND

http://search.digikey

.com/us/en/products/39
-
28
-
8020/WM23800
-
ND/930296

24

$0.96

$23.04

In

stock

PCB connecter

for servos

Mini
-
Fit Jr Male

Connector

Molex

39
-
01
-
2020

Digi
-
Key

WM3700
-
ND

http://search.digikey

.com/us/en/products/39
-
01
-
2020/WM3700
-
ND/61315

24

$0.63

$15.12

In

stock

mates with

pcb connector

Mini
-
Fit Jr Female

Crimp Connection

Molex

39
-
00
-
0207

Digi
-
Key

WM3116CT
-
ND

http://search.digikey

.com/us/en/products/39
-
00
-
0207/WM3116CT
-
ND/1643463

48

$0.36

$17.28

In

stock

mini
-
fit contacts

Molex KK

PCB Header

Molex

22
-
23
-
2021

Digi
-
Key

WM4200
-
ND

http://search.digikey

.com/us/en/products/22
-
23
-
2021/WM4200
-
ND/26667

1

$0.44

$0.44

In

stock

roboard power

connector

Molex KK

Female Connector

Molex

22
-
02
-
2025

Digi
-
Key

WM3200
-
ND

http://search.digikey

.com/us/en/products/22
-
02
-
2025/WM3200
-
ND/26543

1

$0.62

$0.62

In

stock

mates with

KK pcb header

Roboard RB
-
100

Roboard

RB
-
100

Trossen

Robotics

KIT
-
C
-
900
-

Roboard
-
Kit
-
110

http://www.trossen

robotics.com/p/roboard
-
rb
-
110
-
starter
-
kit.aspx

1

$309.99

$309.99

In

stock

central

Processing

Infrared Proximity Sensor Short
Range

Sharp

GP2D120XJ00F

Sparkfun

SEN
-
08959

http://www.sparkfun.com/products/8959

4

$13.95

$55.80

In

stock

Obstacle

Avoidance

Ultrasonic Range Finder

Maxbotix

Maxbotix LV
-
EZ0

Sparkfun

SEN
-
08502

http://www.sparkfun.com/products/8502

1

$27.95

$27.95

In

stock

Ordered 1 with free Sparkfun
money

6 Degrees of Freedom IMU
ITG3200/ADXL345

IMU

N/A

Sparkfun

SEN
-
10121

http://www.sparkfun.com/products/10121

1

$0.00

$0.00

In

stock

Combo Board, Ordered with
free Sparkfun money

EasyVR Shield
-

Voice Recognition
Shield

VR

N/A

Robot Shop

RB
-
Tig
-
01

http://www.robotshop.com/vrbot
-
voice
-
recognition
-
module
-
for
-
robonova
-
and
-
other
-
robots.html?utm_source=google&utm_medium=base&utm_campaign=
jos

1

$50.00

$50.00

In

stock

Speech Recognition

Module

Totals



$600.85