Learned From Past Years

One of our team goals this year was to make it to the semifinals (at least) at the Ontario District Championship. Here's what we implemented to make it there:

POE to Radio:

Provides redundant power to the radio.

Battery Zip Tie:

We locked our regular battery connector with a reusable zip tie to ensure the battery wouldn't come unplugged on the field.

Compression Fittings:

The compression fittings provide a more secure connection with a historically lower risk of disconnecting. We seem to have bad luck with push fittings, so switching to compression fittings reduces the chances of a pneumatic failure.

Weidmuller Ferrules:

Weidmuller Ferrules help to insulate the wires going into VRM, PCM, PDP, and Rio. They encapsulate the wire stands and prevent stray strands from shorting, and provide a robust connection.

Software and Controls

Sensors:

NavX (gyro and accelerometer), SRX Mag Encoders, Laser Time of Flight (distance) Sensor

Motor Controllers:

Talon SRX and Victor SPX, using CAN

Autonomous:

Bezier splines to plot paths, followed with feedback from encoders and gyroscope

Controls:

Automatic movement to default positions; manual adjustments (within limits) and overrides if needed

Systems Check:

Drives each output independently; tests individual motors, encoders, and pneumatics

Test Suite:

We wrote a built-in test suite to cycle through every motor controller on the robot using one button on the controller. This will instantly tell us which motors are and are not functioning, allowing us to easily diagnose any issues we have with the robot.

Arm-Wrist Synchronization:

• The arm and wrist are synchronized with a cubic regression computed with a set of points, so that the wrist position is a function of the arm position. We set the target points as constants, and the robot computes the curve of best fit.
• There were two constraints on the arm-wrist synchronization: first, the arm and wrist had to remain within 16". Second, it had to get the wrist out of the way fast enough to not have the cube or wrist collide with the elevator. The curve also needed to be adjusted for variations in chain tension, so having the robot dynamically calculate the curve was significant.

Performance

• Can deliver cubes to switch, scale, exchange
• Can retrieve cubes from portal, floor
• Can climb and lift a second robot
• Top 1% in the world (2018)

New Initiatives

SolidWorks Bootcamp:

Mentors gave interested students a crash course in designing, drafting and preparing parts for the CNC mill

Roving Pit Crew:

This year, we created a special subteam for competitions known as the roving pit crew. A couple students (usually a mechanical student and a programming student) would check in on any teams that we saw needed assistance and get them back up and running again