The Minions' Page - Mini Sculpture

Requirements

Autonomous sculpture controlled by one NXT
At least one motor and sensor
Human interface that changes an aspect of the design
Simulation of key features on Working Model 2D
RobotC code used for automation

Design Concepts

After a brainstorming session with the entire team, we came up with a variety of ideas, and decided to move forward with two. The designs were drawn up, and we chose to create a Pugh chart of the four best designs. Based on the chart, we decided to prototype two of the designs (highlighted below in green).

Motorized Gate: moving track stopper to allow balls in and out

Marble Race Track: moving track pieces to change the path of the balls

Marble Sorter: sorts balls into dark and light

Cup Mover: the cup moves to catch balls on different tracks, ending on one track

Motorized Gate Sketch

marble runs down a slope, presses down on a touch sensor
touch sensor activates a gate on another ramp
gate opens, allowing a different marble to run down slope

Marble Sorter Sketch

marble runs down a track
rolls past a light sensor
- light sensor measures "value" of marble (light/dark)
sets off motor that spins basket platform to sort the marble

Analysis & Results

Our final idea ended up being a combination of the two better ideas that we prototyped. We spent time building and coding the structure, and tested it multiple times to ensure it worked consistently. We also designed our human interface to have the cup values switch if the button was being held down but this changed in our later final sculpture.

Physics concepts

d = the distance the ball travels after coming off the ramp

h = the height of the downhill ramp portion

y = the height of the flat ramp portion to the ground

g = 9.8 m/s (force of gravity)

horizontal velocity (v_x) = √ (10/7 ⋅ h ⋅ g)

time (t) = √ (2y/g)

The distance (d) is based on the horizontal velocity of the ball and the time: d = v_x ⋅ t

Result: d = √ (20/7 ⋅ h ⋅ y)

40c9e6864aa044d3a6481b84a64c1901.MOV

Programming Flowchart

We also simulated our sculpture in Working Model 2D. We did have to slightly modify some features of the sculpture, such as the rotating platform, to allow the sculpture to be simulated. However, our simulation still is accurate to the proportions and functions of our real sculpture.

Motorized Gate Blue.avi