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Autonomous Robot Cleanup

Description

This robot collects ball, places them on top of cubes and sorts the cubes into their respective corners

Problem

My dads warehouse needed to be organized, but only being one person, it was a time and energy consuming process. This is where I offered to create an autonomous robot to remove this hassle

Plan/Solution

Materials Used

Vex Elements

Vex Starter Kit

Vex Field

VexCode IQ

  • Vex Field
  • Vex Elements
    • Cube
    • Balls
  • Vex Starter Kit
    • Bars to construct
    • Pins to connect bars
    • Motors to allow for movement
    • Axles to extend a motor's rotating power
    • Gears/sprockets to change gear ratios (for speed or torque)
    • Sensors to detect real-world objects
    • Brain to control all the electronic components
  • VexCode IQ to code the logic for the robot

How It Works

  1. First Path
    • The robot uses its drivetrain's four primary wheels along with the center omni wheel to move diagonally towards the first ball spot.
    • It then moves forward while intaking the two balls.
    • The track then switches, and when the front bumper detects the wall in front of the robot, it stops its forward movement.
    • With 2 balls in the ball track, the robot moves backwards and begins to approach the second ball spot.
    • It then moves forward while intaking the last two balls.
    • With the full ball rack, the robot then approaches the first cube with its back.
    • As the back bumper detects the presence of the cube, it releases the ball rack onto the top of the cube.
      • The color sensor detects the color of the cube.
    • The robot then makes the decision of which corner to bring the cube, based on the color.
    • The robot rotates to have the front face the cube, so that the intake can grasp onto the cube and drag it to its respective corner.
  2. Second Path
    • This process is repeated from path 1, but mirrored for the other side of the field

Building Process

Drivetrain

  • 5 omni wheels, four in a normal tank configuration, with the 5th perpendicular to the rest, in the middle of the drive train
    • This allow the robot to move side to side without turning

Intake

  • A tank tread with scoopers attached transitions the balls from the floor horizontally, to the vertical cage, to the horizontal ball rack.
  • The scoopers additionally have pins attached to the opposite end, so when reversing the intake motor, the pins can lift and furthermore drag cubes around.

Track Switch*

  • Once ball track one is full, the track switch, switches the balls flow into track two

Ball Release*

  • Once the ball rack is full, the ball release allows the balls to freely fall onto the top of the cube

Brain & Sensors

Brain

  • This allows code to control the motors and take inputs/output to the various sensors

Sensors

Touch LED

  • Once pressed, the program begins. The colors displayed on the sensor have their own meaning:
    • Yellow: Running intro
    • Blue: Running blue condition
    • Red: Running red condition

Front Bumper

  • Once this bumper is pressed down, the front of the robot must be pressed up against a wall
  • This is used in the code to stop moving forward, after intaking a pair of balls

Back Bumper

  • Once this bumper is pressed down, the back of the robot must be pressed up against a cube
  • This is used in the code to stop the backwards movement of the robot, in order to ensure that the ball release works smoothly

Color Sensor

  • This sensor determines the color of a cube when in its vicinity, in order to control the decision-making process of the robot (which corner to put a cube where)

Mechanisms

Differential Gearbox

  • A differential gearbox allows one motor to control two different output shafts
  • When the ball Release mechanism reaches its (left or right) stopper, the shaft connected to Arm A stops turning, (it creates resistance that prevents its shaft from turning). When Arm A reaches its stopper, the differential responds by redirecting the power to the path of least resistance—Arm B—allowing it to move instead. Similarly, when Arm B hits its (LEFT OR RIGHT) stopper, its shaft stops, and the differential shifts the power back to Arm A.
  • This mechanism is commonly used in cars to support each wheel moving at different speeds (gif of differential in car)

Code

Keypad.ino

Results

I was able to create a prototype of a autonomous robot, that could mimic the tasks a robot needed to organize a warehouse could do.

Challenges/Lessons Learned

I only had 5 motors so i had to control 2 mechanisms with one motor

  • I learned how to use the differential in order to control 2 different output shafts using one motor