Game: Aerial Assist
Our robot: Vanguard
Aerial Assist is the 2014 FIRST Robotics Competition game. Alliances of three teams each compete by passing, shooting, and scoring with 20” diameter exercise balls. Points can be scored by cooperating within an alliance to use multiple robots to score, placing the ball in low or high goals, or by shooting the ball over a 6′ truss that spans the middle of the field.
Vanguard, our 2014 Aerial Assist rookie robot, was crafted to perform as a heavy, reliable robot capable of easily inbounding, defending, and scoring in low goals. Due to the robot’s dual 14lb. weights on either side, Vanguard excelled at blocking offensive robot strategies. While on the opponent’s inbound side of the field, the net frame could easily block inbounds from human players. As our rookie robot, Vanguard was designed with simplicity, with the focus on a robust, reliable structure.
Vanguard’s drivetrain sported a six wheel “West Coast Drive”, with front and rear wheels on a center wheel drop. The drivetrain was powered by 2 standard AndyMark KoP gearboxes, with 3 CIM Motors each. Each motor was controlled by Jaguar motor controllers.
Vanguard’s controls system used Wi-Fi broadcasting communications along with a NI cRIO. All motors on the robot were controlled by Jaguar speed controllers. Our pneumatic arms were controlled by a Vex Pro Spike relay and solenoid.
The roller arm is composed of a 1/2″ hex aluminum stock supported by two aluminum box beams. Green 30A durometer wheels ride on the hex stock which is constrained by hex bearings and hex split shaft collars. The drive side has a 16 tooth #25 chain hex-bore sprocket that is driven by a ~50 inch chain loop that connects to another 16 tooth sprocket on the output of the gearbox. The gearbox is an Andymark single stage planetary with a 13.5:1 gear ratio and is powered by a mini-cim controlled by a jaguar motor controller. The entire assembly can pivot forward (out 20″ max) and backward (into the robot) to grab and then retain the exercise balls. This pivoting is controlled by two 8″ throw, 7/8″ bore SMC pneumatic cylinders, with rubber dampers to absorb the shock load. The cylinders have flow speed valves on the input and output ports, allowing us to tune the release and return speed so we don’t lose the ball in transit.The two aluminum box beams have two high-quality bronze flanged bearings that ride on steel shoulder screws for robust and smooth actuation.
Vanguard came loaded with two 14lb. steel blocks attached to the frame of the robot. These weights successfully allowed for maximum pushing force, especially helpful in defensive pursuits on the field. Due to our weights, Vanguard weighed in at nearly 118 pounds.
On the field, Vanguard was controlled using two operational joysticks. One joystick was used to actuate the pneumatic roller intake system, while the other was used to control the drivetrain.