Badger Gate

1
Badger Gate

• INTEREGR 160
• Team Amit
• Professor John Murphy
• S.A. Amit Nimunkar
• Client Mark Novak

2
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

4
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.

5
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
9
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.
10
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

19
Cost Report

• Estimated Price List for Full Scale Gate

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Video Demo
Gate Video Demo
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Questions
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Calculations Summary

• Torque data
• Torque ForceDistance abs(F)abs(d)sin(?)
• Theta the angle between the moment arm and the
  direction of the force.
• TFdcos(a)
• Alphathe 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
  T0.10667(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 ? 2p/1.4 radians per second
  Motor speed
• Diameter of spool 1.5 inch
• Tangential Velocity of spool (1.5)(p/1.4) inches
  per second
• D vt (.75)(2p/1.4)(time)
• D/(p(1.5)) of turns of spool
• D ((7.5)2(6)2)(1/2)
• Minimum Time D/V2 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)I?2
• Derived formula for rotational inertia of gate
  (model and scaled up) I (1/3)mL2
• L length of moment arm and m mass of gate
• K (1/6)mV2
• V L? velocity of gate 4p/2.25 inches per
  second
• Mass of scaled down gate 1.00 Kg
• K (1/6)(1.00kg)(((p/2)/2.00)2)((2ft)(1/3.25))
  0.0389 joules of kinetic energy for the prototype
  gate
• Power Work/Time
• Work ? 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