SPLATSmall robotic Platforms for Limited Access

Terrain

Project Sponsor: Eglin Air Force Base Munitions Directorate Air Force Research Laboratory

Contact: Mr. Jeffrey Wagener

Team # 5:Jeffrey Dalisay

Michael GenoveseIvan Lopez

Ryan Whitney

2

Statement of Need/Problem Definition

• In order to collect accurate and sufficient intelligence, there is a need for small platforms that can maneuver on both horizontal and vertical surfaces. Design subsystems that would allow a small robotic platform to:

– Transition between horizontal and vertical planes

– Translate vertically a minimum of 5ft

– Remain on the vertical plane for 30 minutes

– Be confined by a box no bigger than 6”x6”x6”

3

Objectives

• Design and fabricate vertical wall crawler concepts for a small robotic platform

• Optimize subsystems for performance, size, and weight, by addressing material selection

Michigan State crawler

Clarifying Technologies

Michigan State flipping robot

4

• Motion

– Wheels

– Legs

• Adhesion

– Not all surfaces are magnetic

– Adhesive substance or fluid will get dirty

– Wall damage could cause surface failure

• Control

– Radio

– Digital

Design Idea Generation/Necessary Components

• Electromagnetic Robot

• Cart with adhesive tracks

• Cart that secretes adhesive fluid

• Drilling Robot

• Cart with blower/turbine

• Suction Robot

• Suction Car

Ideas Necessary Components

5

Concept 1: Cart w/ Blower

Thrust from the blower will force the cart against the wall, and the wheel in front will help the transition between the floor and wall.

6

Concept 2: Robot w/ Suction

Transition from ground to wall will use three axes of rotation (one for each suction cup and one in the middle).

7

Concept 3: Suction Car

8

Cost Size Ease of Assembly Ease of Operation Power Consumption/Speed Mobility Total0.175 0.225 0.125 0.1 0.15 0.225

7 8 6 7 4 71.225 1.8 0.75 0.7 0.6 1.575

5 7 5 5 6 80.875 1.575 0.625 0.5 0.9 1.8

3 5 4 7 4 70.525 1.125 0.5 0.7 0.6 1.575

6.65

6.275

5.025

Idea

Blower

Suction Robot

Suction Car

Design Matrix

• Weighting factors were determined based on the needs specified by the customer

• Scores were determined by a general consensus of all group members

• Blower seemed to be the “best” overall design based on the total ranking.

6.65

9

Necessary Componentsfor Blower Design

Movement• Motors (2)

• Wheels

• Tracks

Blower Concept• Impeller/Propeller

• Stronger motor

• Duct

Radio Control (RC)• Radio

• Receiver

10

Radio Control

4/6 Channel Transmitter

• 1 channel for each motor (3)

• Extra channels for possibility of added components

Receiver

• 1 port for each channel

• Connects transmitter to motor

Speed Controls

• 1 for brushless motor

11

Fan

• Wattage PowerFan w/ 400f Brushed Motor

• Park 400 Brushless Motor

– 4200 RPM/Volt

– Total Weight = 3.78oz

– $54.99

• Specs

– At 10V 9A, Thrust = 9.5oz, RPM = 20700

– Total weight = 4.13oz

– Outer diameter = 3.1in

– $43.74

12

Radio

• Hitec Laser 6

– 6 channel 75MHz FM transmitter

– Elevon mixing

• Control all motion with the right joystick alone

• Left joystick for the fan

– $134.99

– Also included:

• Supreme 8 channel receiver

• 2 HS-325 servos

13

Body: Fiberglass

Fiber

• Mat

– Resin distributes by itself

– Unorganized fibers

– ~$2.50/yard (1yd by 38”)

• Cloth

– Patterned (squares)

– Must work resin in more thoroughly

– Isotropic Properties

– ~$5/yard

Resin

• Polyester

– Cheap

– Relatively strong

– ~$10/Quart

• Epoxy

– Higher Strength

– Bonds to metal

– ~$20/Quart

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Body Construction

Initial Creation• Foam was used to create body

molds

• Cloth then laid down and Epoxy brushed on

• Different angles used for fan

Improved Method• Cutting strips is easier to shape

around the fan duct

• Cloth was dipped in hardener, and set onto platform

• Platform then cut to size

• (See Picture)

15

Fan Testing

Motor Characteristics

- Power(Voltage,Current)

-Thrust(Power)

16

Initial Results

Thrust vs. Power

0

24

68

1012

14

0 20 40 60 80 100 120 140

Power (W)

Th

rust

(o

z)

400f Brushed Motor

Park 400 SeriesBrushless Motor

Thrust vs. Power of both the Brushed and Brushless 400 motors

Points from Fan/Motor Manual

17

Drivetrain

• Attaching the axles

– Plastic braces for support, and then glued to body

– Wheels put on, and axle tips burned

• Motors

– Brushless were first used

• Needed to handle 12V

• Too heavy(1.6oz each), too much speed

– Servos then purchased

• Made continuous

• Lightweight (.6oz each)

18

Drivetrain cont…

• Different designs:

– Bodies made with different wheels, and motor setups

• Front wheel/rear wheel drive

• Some had idler wheels

• Varying wheel sizes to change ground clearance

19

Optimizing Traction

• Maximize friction without overloading the motors

• Numerous treads were tested

– Electrical, Double sided, and waterproof tape

– Rubber bands

– Spray Adhesive

20

Final Mockup

• Front wheels to help vertical transition

• 2 continuous servos for motion

• Final design has shorter track widths with body stiffener

21

Final Design

22

Improvements

• Quicker servos for a faster platform

• Metal gears to reduce slippage and stripping

• On board Power source

• More efficient impeller

• Better driving wheel coupling

23

Acknowledgments

• Mr. Jeffrey Wagener and Dr. Joel House: Contact/Sponsor at Eglin Air Force Base

• Jeff Radkins: Owner of Hobbytown USA

• Kyle: Global Hobby

• Jon Cloos: Purchase Orders

• Dr. Luongo

• SAE Club for fiberglass help