VEX IQ Challenge (VEX_IQ_Challenge_Highrise_Game.pdfVEX_IQ_Challenge_Highrise_Game.pdf) Overview
The VEX IQ Challenge consists of the VEX IQ Challenge Highrise robot game and the optional STEM Research Project. The VEX IQ Challenge provides an opportunity for students, with the guidance of an adult mentor, to explore and solve exciting science, technology, engineering, and mathematics (STEM) challenges.
Students develop valuable knowledge, skills, and experience and a tremendous sense of accomplishment in building a robot and developing a STEM research project to compete in the VEX IQ Challenge.
VEX IQ CHALLENGE HIGHRISE
Two robots work collaboratively, as an alliance, to score points in Teamwork Challenge matches of 60 seconds in length. Teams can also participate in two additional challenges; The Robot Skills Challenge, where one robot takes the field to score as many points as possible under driver control; and The Programming Skills Challenge, where one robot scores as many points as possible autonomously, without any driver inputs.
The object of the game is to attain the highest possible score by moving Scoring Cubes into the Scoring Zone and by building Highrises of Cubes of the same color on the Highrise Bases.
There are a total of thirty-six (36) Cubes, twelve (12) of each color, available as Scoring Objects in the game. There is one (1) Scoring Zone and three (3) Highrise Bases on the field. Each Robot (smaller than 13x19x15 inches to start) begins a match on one of two Starting Positions.
Each Cube Scored in the Scoring Zone is worth a point value equal to the Highrise Height of the same color as the Cube. That is, if a team builds a Highrise of 3 red Scoring Cubes on the Highrise Base, a red cube in the Scoring Zone is worth 3 points.
Rather than lifting and stacking the blocks, we decided to simply pull the blocks into the scoring zone. To keep this simple, we decided not to use pneumatics or motors (which would require additional programming). Instead, we decided to use a simple friction based system with a little assistance from Gravity. The Lego cannon parts with rubber tips act as a one-way valve allowing the blocks to pass through them in one direction. Once the robot reverses direction, the rubber tips create a certain level of friction against the blocks (holding them in place inside the robot). The weight is used to help apply a little force to the rubber tips.
One key feature of the robot is the line following. Since the blocks are centered on a straight line, we knew the robot would need to use a light sensor to align the robot to the blocks and an ultrasonic sensor to detect when the blocks were near. It was important that the sensors not interfere with the collection of the blocks themselves. Therefore it was necessary for the sensors be able to move out of the way when the blocks are encountered by the robot. This was done by placing the sensors on an axle that allowed the sensors to safely move above the blocks when pushed over them. A roller bar on the sensor assembly acted as a bearing that facilitated the sliding of the sensor assembly up-and-over the blocks as the robot gathered 4 blocks at a time.
LDD Files for the different parts of the robot: Chassis, Sensor Assembly, Block Gripper
It may help to build this model as separate components which are attached later.
The robot used for this competition used an older NXT brick with a non-functioning display. A menu program was developed that utilized sound files to alert the user to which menu item was selected.
Though technically it was possible to have only one program on the Lego NXT brick, we wanted to be able to run at least two separate programs in different events during the competition day. Therefore it was useful to have a Program Menu that allowed the user to select which program to run. The lack of a working NXT display meant that audio feedback from the NXT brick would be important to be able to use it effectively.
