OTTER ENRICHMENTAditya Yadavalli, Vamsi Varra, and Michael Mathison

Client: St. Louis Zoo

Section 2 | Group 21

Outline

1. Need/ Project Scope

2. Design Requirements

3. Design Alternatives

4. Analysis of Alternatives

5. Chosen Design Specifics

6. Update

Introduction | Alternatives | Analysis | Chosen Design

Need and Project Scope• Oscar the Otter at the St. Louis Zoo resides in an exhibit

that lacks many characteristics that are typical of a natural habitat

• Needs: Fully functional enrichment device enhancing Oscar’s mental and physical health

Introduction | Alternatives | Analysis | Chosen Design

Specific Design Requirements• Cost Maximum: $50• Cannot be used to escape exhibit

• River Otters jump up to 6 feet

• Buoyant• Electronic components must be waterproof

• Indestructible• Bite Strength: 223.4N

• Wieldable• River Otter paw dimensions: 9.05 cm X 7.62 cm

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

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

Introduction | Alternatives | Analysis | Chosen Design

Design Alternatives – Pugh Analysis

Introduction | Alternatives | Analysis | Chosen Design

Weight Otter BallPuzzle

BoxMoving

MazeTether

BallWhack-

a-moleWotter Wheel

Cost 3 2 -2 -2 1 -2 0

Durability 2 2 2 2 -2 0 2

Physical Enrichment 1 -1 0 -1 0 2 2

Cognitive Enrichment 2 -2 2 2 -2 1 -2

Sensor Integration 2 0 2 -2 1 1 2

Novelty 1 -2 2 1 -2 1 2

Production Feasibility 2 1 -1 0 2 -2 -1

Net Score 5 6 -1 -1 -3 6

Rank 5 T2 T8 T8 12 T2

Design Alternatives – Pugh Analysis

Introduction | Alternatives | Analysis | Chosen Design

WeightStacking

BoxesShell-

CrackerMechanical

Fish BasketballDiving Hoop

Puzzle Ball

Cost 3 2 -2 -2 2 2 2

Durability 2 0 2 1 1 -2 2Physical Enrichment 1 0 1 2 2 1 0Cognitive Enrichment 2 -2 -1 2 -2 0 2Sensor Integration 2 -1 1 2 -2 -2 0

Novelty 1 -2 -1 2 -2 -2 2Production Feasibility 2 2 -2 -1 2 1 0

Net Score 4 -6 6 2 -1 16

Rank 11 13 T2 7 T8 1

Design Alternatives- Puzzle Box• Tactile 4’x4’x4’ box - thermoplastic ABS (Durability)• 4 Recesses of a variety of shapes with corresponding

blocks• Otter places blocks in appropriate recess • Incentivized by food reward as appropriated by caretaker• Sensors: Force (Recess) and Accelerometer (In blocks)

• Cognitive enrichment quantification - Accelerometer• Physical enrichment quantification- Force and Accelerometer

• Eliminated• Difficult to 3D print such large objects• Physical enrichment is minimal• Prohibitive cost

Introduction | Alternatives | Analysis | Chosen Design

Design Alternatives- Wotter Wheel• Wheel made of wooden planks connected by a central

axle- coated with high resistant vinyl to prevent slipping• Otter runs around wheel to obtain food reward• Sensors: Accelerometer (In central axle)

• Physical enrichment quantification- Accelerometer

• Eliminated• Finishing of planks and application of vinyl • Slightly outside budget• No cognitive enrichment• Unnatural movement

Introduction | Alternatives | Analysis | Chosen Design

Design Alternatives- Mechanical Fish• Remote controlled mechanical fish with an anterior and

posterior motor• Controlled by zookeeper to emulate a hunting scenario for

otter• Sensors: GPS and Accelerometer (In fish)

• Cognitive enrichment quantification- GPS• Physical enrichment quantification- Accelerometer

• Eliminated• Prohibitively expensive • Not too durable and not reusable if caught by otter• Difficult to manufacture a convincing mechanical fish

Introduction | Alternatives | Analysis | Chosen Design

Chosen Design- Puzzle Ball• A 15 cm diameter, 2 lbs hollow ball constructed of ABS

thermoplastic polymer with two shells• Otter must unscrew two differing size shells to open the

ball and get rewarded by food inside the ball• Sensors: Accelerometer and gyroscope (located on inner

shell) • Cognitive enrichment progress monitored by

• Improvements in the speed at which the otter solves the puzzle (accelerometer)

• Decrease in orientation variations (gyroscope)

• Physical enrichment progress monitored by• Speed variations reflecting dexterity improvements (accelerometer)

Introduction | Alternatives | Analysis | Chosen Design

Chosen Design- Puzzle Ball• Durability- ABS polymer

• Rigid matrix interspersed with the synthetic rubber polybutadiene

• 2 Shells• 1st shell: 0.4 cm thick, 2 interlocked hemispheres

• One hemisphere has a groove running along the perimeter that widens at one specific position on the perimeter

• Second hemisphere has a normal perimeter with a protrusion that fits into the groove.

• Protrusion is only released from groove at the widened area

• 2nd shell: 0.6 cm thick, houses sensor, 2 interlocking hemispheres• Located inside the 1st shell• Same locking mechanism as first shell

Introduction | Alternatives | Analysis | Chosen Design

Chosen Design- Puzzle Ball• Sensor Setup: Adafruit Inertial Measurement Unit, Arduino

microcontroller, WiFi Chip (total thickness 4mm)• Adafruit IMU consists of two sensors: gyrometer and accelerometer

(3 DOF each)

Introduction | Alternatives | Analysis | Chosen Design

Adafruit IMUArduino

ProcessorWiFi Chip

Gyrometer

Accelerometer

Server

I2C Bus I2C Bus

Chosen Design- Puzzle BallNovelty

• Potential as a predictive/diagnostic tool • reduced strength due to illness or reduce cognitive function due to

neurodegenerative ailment

• Cognitive challenge is accurately difficult• Promotes enrichment in addition to an active involvement in otter

health by the caretakers

Introduction | Alternatives | Analysis | Chosen Design

Future Plans

Date Objective

Nov 3rd Complete Sensor Construction

Nov 19th Finish and turn in peer reviewsNov 20th Complete 3D printing and construction of PrototypeNov 20th- 29th Test prototype at St. Louis Zoo

Nov 29th

Finish rough draft of final report and send to Dr. Klaesner for review

Dec 1st Turn in finished version of final report

Dec 3rd

Final oral report and presentation of prototype done by Michael

Dec 20th Conversion of prototype into a lasting, working model

References"Adafruit 9-DOF IMU Breakout - L3GD20 + LSM303." Adafruit Industries. Adafruit, 29 Nov 2013. Web. 26 Oct. 2014.

"Animal Tracks - River Otter (Lutra Canadensis)." Bear Tracker. N.p., n.d. Web. 24 Oct. 2014.

AZA Small Carnivore TAG 2009. Otter (Lutrinae) Care Manual. Association of Zoos and Aquariums, Silver Spring, MD.

Carss, David N. “Foraging Behavior and Feeding Ecology of the Otter Lutra Lutra: A Selective Review.” Hystrix. Scotland, UK: Institute of Terrestrial Ecology. (179-194). 1995 .

Seymour, Raymond B. "Origin and Early Development of Rubber-Toughened Plastics." Rubber-Toughened Plastics (1987): 3-13.

"Square Force-Sensitive Resistor (FSR) - Interlink 406." Adafruit Industries. N.p., n.d. Web. 23 Oct. 2014.

"Stainless Steel 3D Printing Material Information - Shapeways." Shapeways.com. N.p., n.d. Web. 23 Oct. 2014.