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Otter PuzzleBallKunal Patel (ESE) & Michael Mathison (BME)

ESE 499St. Louis Zoo

Need and Project Scope

Oscar’s habitat lacks many of his natural needs due to it being an artificial environment.

Need: Fully function device to enrich Oscar’s mental and physical health

Specific Design Requirements

Cost Maximum: $150

Cannot be used to escape Otters can jump 6 feet

Buoyant Electronic parts must be waterproofed

Indestructible Bite strength of 223.4N

Design Requirements Cont.

Wieldable Otter paw dimensions: 9.05cm x 7.62cm

Should not cause or encourage over-activity, stress, obesity, or illnesses

Contains sensors to gather data to quantify otter’s health and enrichment levels General behavioral data

BME Analytical Efforts

Destruction by otter

Buoyancy

Reusability

Durability - Otter Destruction

Durability - Otter Destruction

Valuable items inside of the ball - Arduino and food

River Otter jaw - 3 pairs of incisors instead of 4 like most otters Ball must be larger than jaw (10-12cm)

Gnawing issues Bite strength of 223.4N Plastic (1.75mm ABS) ultimate strength of 40MPa Needed surface area of 5.6x10-4 cm2

Radius concluded to be 8cm

Durability - Buoyancy

The ball is mainly hollow due to two compartments - sensor and food

Sensor setup is 473g

Total volume of plastic used is 804 cm3 with weight of 2128g

Final weight of 2601g

Based on volume, 2145g of water displaced

Buoyancy Solution

Paddles added with hollow spheres

Chosen Design

Two interlocking hemispheres - food containment and Arduino container

Locking Mechanism

Sensor Network

Food Hemisphere & Container

Sensor Hemisphere

Locking Mechanism

Parts and Manufacturing

1.75mm ABS plastic

7 parts connected using adhesive, except sensor lid

Sensor Network

Overhang Issue

Outer and Inner Track

Rail Plate

Rails

Bodies

Sphere Lids

Sensor Network

Three parts Sensors, Microcontroller, Wi-Fi Shield

Battery Supply 8 AA Lithium ion rechargeable batteries

Microcontroller Selection

Why the Arduino Uno?

Microcontroller Properties

Arduino Uno

Software C++ Mainly from open source libraries

$29.95

Sensor Selection

Adafruit Inertial Measuring Unit (IMU) Accelerometer & Magnetometer (LSM303) Gyrometer (L3GD20H)

$19.95

Wi-Fi Shield

Purchased separately form the Arduino ($29.95)

Enables transmission of signal to remote computer on network every 10 minutes

Main source of power consumption

Battery Selection

Rechargeable AA batteries because of 1A and 9-12V requirement of Arduino with Wi-Fi shield

Final Electronics Build

Software and Demonstration

Arduino and sensors collect data every second

Transmits data for 10 minutes

Transmits data to host computer

Host computer translates raw data into relevant measurements

Conclusion

Enrichment issue has been solved

Possibility of behavioral studies

Expand sensor threshold to include accelerometer data Potentially give data on solve speeds

What was learned? More CAD experience, otter facts, working with a customer,

working in a group

Different strategy - Delegating work often increased efficiency, but sometimes led to miscommunication problems

Questions?