Author Topic: Hardware Presentation 1/23  (Read 601 times)

Shreya C

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Hardware Presentation 1/23
« on: January 23, 2018, 10:24:18 PM »
Chassis:
  • Need to design a jig for perfect wheel alignment
  • List of actuators:
    • 4 swerve units
  • List of sensors:
    • One encoder on PG27 of one swerve unit

Intake:
  • Frame pivots up & down
  • Intake should only be down when intaking a cube; otherwise, should be in the upright position for protection
  • Spring-loaded mechanism brings the arms in
  • In "released" position, arms will extend straight out at 90°
  • Wheels on arms to bring cubes in — will need to experiment w/ the sizes + speeds for the wheels
  • Overall process of intaking a cube:
    • Intake goes down
    • Wheels on arms squeeze the cube in
    • Arm drops down to pick up the cube
    • Intake raises to upright position
  • List of actuators:
    • Bosch seat motor w/ pulse generator controls pivoting of the intake frame
    • 2 motors for wheels on intake arms; fixed rotation at 1000rpm
  • List of sensors:
    • Limit switches for upright & downright pivot position; for downright position, the intake will also hit the chassis frame
    • Limit switches to detect the corners of a cube (at corners of intake frame, where intake arms meet the chassis frame and intake frame)

Arm:
  • Supported by two towers mounted to the back of the robot
  • Arm bends down and retrieves cube from the intake, with the intake in its upright position
  • Arm has extending unit controlled by a 17 inch lead screw (that extends a total of 12 inches) and motor, as well as 18 inch door sliders for even more extension
  • List of actuators:
    • Mini CIM controlling bending of the arm
    • PG27 controlling turning of the lead screw
  • List of sensors:
    • Encoder on PG27 to measure how far the arm has extended
    • Limit switches on each end of the arm's extension
    • Encoder on mini CIM driving controlling of the bending of the arm - use the angle from the vertical to calculate the height of the arm at any given time — we're probably going to do this w/ a lever attached to the arm w/ a potentiometer
    • Limit switch on each end of the arm's pivoting motion
    • Considering setting fixed encoder values for specific heights (refer to this post)

Gripper/Claw:
  • Sliding unit that adjusts to the appropriate width to grip the cube
  • L-shaped pieces with padding that grip the cube
  • Pivots up and down
  • Must be able to handle both heights of the cube (11 in/13 in)
  • Claw must be kept level when accessing the cube
  • When carrying cube, claw must be at 90°
  • List of actuators:
    • Snowblower motor to control sliding mechanism to open & close claw
    • Motor to control pivoting
  • List of sensors:
    • Limit switches for pivoting motion of claw
    • Pressure sensor on L-shaped pieces? would look really cool for the judges. Can also measure the motor current & determine pressure using that.
    • Limit switches on each end of sliding motion
    • Accelerometer/encoder for keeping claw level
Climber:
  • Winch like last year's
  • Nylon strap that goes through back of tower + down the arm
  • Hook on end of nylon strap that attaches to extending mechanism of arm—positioned at right height so that when this mechanism releases, the hook can latch onto the rung
  • Arm drops, intake lowers—robot starts lifting off the ground
  • Strong wrench for ratchet
  • List of actuators:
    • Mini CIM w/ gearbox (64:1 reduction)
  • May not need any sensors!