Animation of a Reuleaux tetrahedron, showing also the tetrahedron from which it is formed.
From Wikipedia, the free encyclopedia
The Reuleaux tetrahedron is the intersection of four balls of radius s centered at the vertices of a regular tetrahedron with side length s.[1] The spherical surface of the ball centered on each vertex passes through the other three vertices, which also form vertices of the Reuleaux tetrahedron. Thus the center of each ball is on the surfaces of the other three balls. The Reuleaux tetrahedron has the same face structure as a regular tetrahedron, but with curved faces: four vertices, and four curved faces, connected by six circular-arc edges.
This shape is defined and named by analogy to the Reuleaux triangle, a two-dimensional curve of constant width; both shapes are named after Franz Reuleaux, a 19th-century German engineer who did pioneering work on ways that machines translate one type of motion into another.
One can find repeated claims in the mathematical literature that the Reuleaux tetrahedron is analogously a surface of constant width, but it is not true: the two midpoints of opposite edge arcs are separated by a larger distance,
VEX Robotics Competition Over Under is played on a 12’ x 12’ square field configured as seen above. Two (2) Alliances – one (1) “red” and one (1) “blue” – composed of two (2) Teams each, compete in matches consisting of a fifteen (15) second Autonomous Period, followed by a one minute and forty-five second (1:45) Driver Controlled Period.
The object of the game is to attain a higher score than the opposing Alliance by Scoring Triballs in Goals, and by Elevating at the end of the Match.
There are sixty (60) Triballs on a VRC Over Under Field.
There are two netted Goals on opposite sides of the field. A 2” PVC Barrier divides the field into a Red Offensive Zone and a Blue Offensive Zone.
Each Triball scored in a Goal is worth five (5) points, and each Triball which makes it into an Offensive Zone is worth two (2) points.
The VRC Over Under Field also includes two sets of Alliance-specific pipes on either side of the Barrier. These are called Elevation Bars, and are used at the end of the Match for Elevating Robots.
At the end of the Match, each Robot’s height off the ground will be measured to determine their Elevation Tier. Elevation Points will then be awarded based on each Robot’s Tier relative to all other Robots. For example, getting to Tier E could be worth as many as twenty (20) points OR as few as five (5). Elevation Tiers begin at the floor, and they end above the Elevation Bar!
The Alliance that scores more points in the Autonomous period is awarded with eight (8) bonus points, added to the final score at the end of the match. Each Alliance also has the opportunity to earn an Autonomous Win Point by completing three assigned tasks. This Bonus can be earned by both Alliances, regardless of who wins the Autonomous Bonus
Future Dates for Manual Updates
August 1, 2023
Version 2.0 - Update may include gameplay or rule changes inspired by early-season events.
October 3rd, 2023
Version 2.1 - Manual Clarification Only
December 5th, 2023
Version 2.2 - Manual Clarification Only
January 30, 2024
Version 3.0 - Update may include gameplay or rule changes inspired by mid-season events
April 2nd, 2024
Version 4.0 - Update may include gameplay or rule clarifications pertaining specifically to the VEX Robotics World Championship.