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Badger Gate

INTEREGR 160Team Amit

Professor John MurphyS.A. Amit NimunkarClient Mark Novak

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About AgrAbility

Mark Novak, a BSE professor at UW-Madison is an outreach specialist for AgrAbility

AgrAbility is a federally funded program with the goal of aiding disabled farmers so they can continue production.

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Problem Statement Our goal is to design a prototype of

an automated livestock gate. The gate must be remotely operated to allow a disabled farmer to stay in the vehicle while the gate opens and closes. It must securely latch in order to serve the primary purpose of keeping all livestock inside the pen. It must also be safe, inexpensive, and reliable

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Brainstorming Two-way Winch

System Powered by a

motorized spool to wind cables attached to the gate.

Electronic Actuator An electronic arm

extends and retracts to push and pull the gate.

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Brainstorming Motorized Wheel

A remote operated wheel drives the gate open.

Motor and Chain A motor rotates a

gear which opens a gate by spinning a chain.

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Evaluation Criteria

Safety Cost Efficiency Reliability Ease of use Installation Maintenance

Opens Manually

Space/size

Power Required

Locks securely

Remote compatible

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Evaluation

Motor and Chain requires a new mounting and difficult installation.

The motorized wheel would be too unreliable.

A decision matrix and a group vote was used to pick a final design.

The winch system was chosen as the final design.

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Final Design

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Model Construction

The basic model was a plywood base, with square, 2x2 fence posts, wire fencing, and a ¾ inch diameter PVC pipe, 2’ by 1’ gate. Eye hooks constituted the hinges, and a plastic wheel can mounted to the end of the gate.

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Pulley System We had several

different ideas for use as the pulley system.

Tensioners were needed to pick up slack in excess cable as the motor rotated.

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Pulley System Solution Utilizes a spring loaded

tube to keep pressure on the cable and take up the slack produced when the gate is opened.

Uses 2 tubes of different diameters that can slide over one another with a spring on the inside.

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Motor and Pulleys

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16-Foot Gate Scaled Calculations Amount of power required to open the gate

is approximately 20 watts. Voltage varies depending on the motor

rating Only 11 watts should have been needed Motor efficiency was calculated into the formula

as error. Wire: Steel cable, rated 480-500 lbs Pulley arms: Wood or steel Other materials can be found on our parts

list.

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Servo-Operated Latch

Powered by servo motor

When power is applied, latch opens

1.25 V DC Operated via

joystick: pushing up opens latch

Closed

Open

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Latch Construction Constructed of

Grade 304 Stainless Steel

Servo contained in waterproof housing

Impervious to water Able to withstand

large forces Will not rust or

freeze

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Latch

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Strengths and Weaknesses

+ The system can be universally mounted on preexisting gates.

+ The gate is able to swing both into and out of the pen.

+ Opens gate quickly.+ Can be opened

manually if system should fail.

- Requires more installation.

- Length of pulley arms and cables take up more space.

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Cost Report Estimated Price List for 1/8 Scale Prototype Gate

Sail winch servo motor $53.95

50 lb. test fishing line $(4.00)

Two-Channel remote with reciever and servo

$39.99

PVC $8.25

Miscellaneous (clamps, bungees, springs, pulleys)

$12.00

Total $118.19

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Cost Report Estimated Price List for Full Scale Gate

½ H.P. Motor $60.00

25ft. 3/32” Nylon coated steel cable $21.15

Two-Channel remote with reciever and servo

$39.99

Steel Bar $60.00

Miscellaneous (clamps, bungees, springs, pulleys)

$60.00

Total $241.14

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Video Demo

Gate Video Demo

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Questions

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Calculations Summary Torque data: Torque= Force*Distance= abs(F)*abs(d)*sin(θ) “Theta”= the angle between the moment arm and the

direction of the force. T=F*d*cos(α) “Alpha”=the complementary angle to the gate Torque conversion: 1.27 Newton meter≈ 180 ounce

inches The motor will exert 183 ounce inches of torque on

the prototype gate. Derived formula used for initial torque:

T=0.10667(tension) Newton meters Wire should be able to withstand above 20

Newtons/4.5 lbs of instantaneous tension

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Calculations Summary Gate speed data: Angular velocity= ω= 2π/1.4 radians per second: Motor

speed Diameter of spool= 1.5 inch Tangential Velocity of spool= (1.5)(π/1.4) inches per second D= v*t= (.75)(2π/1.4)(time) D/(π(1.5))= # of turns of spool D= ((7.5)^2+(6)^2)^(1/2) Minimum Time= D/V≈2 to 2.50 seconds for the gate to open Closing the gate should take approximately the same time The calculations for the gate speed are accurate within less

than a second. The scaled up gate will have to move somewhat slower.

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Calculations Summary Gate Power: Kinetic Rotational Energy formula: K= (1/2)Iω^2 Derived formula for rotational inertia of gate (model and

scaled up): I= (1/3)mL^2 L= length of moment arm and m= mass of gate K= (1/6)mV^2 V= L*ω= velocity of gate≈ 4π/2.25 inches per second Mass of scaled down gate≈ 1.00 Kg K= (1/6)(1.00kg)(((π/2)/2.00)^2)((2ft)(1/3.25))= 0.0389

joules of kinetic energy for the prototype gate Power= Work/Time Work= Δ Kinetic Energy= K(f)- K(i)= 0.0389 joules- 0 Theoretical Power after assumption of 50% error: 0.039

Watts as a maximum. Rating of servo motor (from catalogue): 0.0384 to 0.048