Nightwatch

Our second robot we named after a famous painting "The Night Watch". Painted by the Dutch painter Rembrandt van Rijn. The robot "Nightwatch" was build in the 2014 season for the FIRST Robotics Competition game "Aerial Assist". Nightwatch has competed at the North Carolina Regional in Raleigh and at the FIRST Championship 2014 in St. Louis. With Nightwatch we won the Engineering Inspiration Award at the North Carolina Regional and the Imagery Award in the Newton Division at the FIRST Championship 2014.

For our strategy this season we choose to make Nightwatch very flexible in moving around on the field. Further we want to be able to grab the ball from the ground and pass it to another robot. This because the most points can be earned by assists. Next to that we want to be able to shoot over the truss and into the high goal.

By using 20x20 mm aluminium profile, we ensure the robot can be (dis-) assembled fast. This aluminium creates alight and very strong frame.

The shooting mechanism was designed to be innovative but also to be compact. We started of with a concept where 2 triggers were pulling a chain backwards to wind the shooter. It's a spring powered bar which is connected to the shooter. So, we could throw the ball instead of punching it. The ball would have absorbed the energy of punching. The concept works, but was very slow. There for we changed the concept and used a spindle to wind the springs. A motor is winding up a spindel. A block-on its turn, is connected to the spindel which acts like a hammer from a revolver. This trigger will pull the springs to the back like a pinball machine. The piston on the back pulls the trigger upwards and the energy of the springs will be released allowing to shoot the ball. Unfortunately, by using a CIM motor to wind the spindle, the motor started to become very hot and to use to much amps. To reduce this we made the wiring shorter and placed a CIM cooler on the motor.

The half-moon shaped part allows the robot to scoop up the play ball. When the ball is almost in, the wheels on top turn inwards to make sure the ball can’t get out. The whole mechanism can tilt 90 degrees upwards so we can use it to catch from the ground and from the air.

The electronics are the brains of the robot. This box contains all necessary elements to drive a robot. The electro box contains the following things: Relays, motor Controllers, 20 AMP breaker board, I/O-board and cooling fans. From our experience of last year, we wanted to build an easy removable electro box. So we came up with the electro drawer.

With the help of mecanum wheels Nightwatch is very mobile. Which allows us to drive in all horizontal directions without turning the robot. The main purpose of the wheels is to make positioning as easy as possible for the driver. We choose big wheels over small wheels, because the large size wheels are faster due its perimeter. It is a little bit harder to program, but if things get complicated, bring in the Dutch!