The task

We build a cooperating robot that can fulfill the task of the system engineering project 2020-2021 together with the robot of our partner team.

The mode of operation

The robot starts at a defined point on Building 2. From there, it scans the microcode on the pipes. Once it has found the right pipe, it picks it up with the gripper arm. The robot moves with the pipe to the support. Here, the two robots connect the pipes and place them on the support. Now the robot supports itself on the pipe and pulls itself up. With the gripper arm, the robot moves to the middle of the pipes, where it connects with the partner robot. Together, the robots lower themselves onto the steel support walls and drive to the meeting point.

The concept

The robot is in its starting position.

The robot tilts the gripper arm and moves to the position to scan the first pipe. 
If the scanned pipe is not the correct one, the robot moves under the second pipe. This pipe is also scanned. Once the robot detects the correct pipe, the pipe search is done. If the first two pipes are not the correct ones, the third pipe must therefore be the correct one and the search process can also be ended.

Once the robot has found the right pipe, the gripping process begins. The gripper arm now changes the angle and moves upwards. As soon as it reaches the correct position, the gripper arm opens. The gripper moves to the pipe and closes.
The movement of the rollers causes the gripper arm to pull the tube out.

The gripper arm changes the angle so that it is straight again and moves up. The tube is brought into the correct position and the robot moves to the coupling point.

The robot then moves the pipe to the center, where the pipe is coupled with that of the partner team. Together, the robots lower the connected pipe onto the support.

The robot pulls itself up and moves over the pipe to the center. In the middle, the robot connects with the other.

The gripper arm is opened and the robots lower themselves onto the rail.
Together they travel on the rails to the target.

The subfunctions

Movement on the surface: 2 driven wheels and balls

The movement on the surface is done with two wheels, which are connected by an axle. These are controlled by a motor so that the robot can only move in one direction. The rest of the movements have to be done by the arm. Two balls are used to stabilize the robot so that it does not tip over. A reflex light barrier is installed on the underside of the robot. This measures the brightness of the ground, whereby markings on the ground are recognized. The robot knows where it is on the playing field based on these markings. 

Gripping tubes and movement on the tube: gripper arm with 4 rollers

Gripping and movement on the pipe is performed with the same gripper arm. 
The gripper arm consists of 4 rollers, one of which is driven and can be opened or closed. A camera is mounted on the arm, which is used to read the microcode. In addition, a reflex light barrier is attached to the arm, which detects markings on the pipe and thus recognizes the position. The entire gripper arm can be extended and tilted to scan, grip and position the pipes. 

Pipe connection: Pivot with magnet

The connection between the two pipes is made by means of pins and magnets. Pins are already attached to the pipes. Inside the spigots are magnets, which are also fixed with adhesive. If the tubes are now joined together, they are centered by the round shape and held together by the magnets.

Robot coupling: magnets

The robots must couple in order to pass the rails together.  Three magnets are attached to the side of both robots using adhesive. The magnets are arranged as a triangle. The two robots are held together by the magnetic attraction.  A microswitch detects the successful coupling of the robots.

Movement on rail: stored roller

The robot must move down on a rail to reach its final position. Two rollers are mounted on the underside of the robot. The robot rests on these rollers on the rail and rolls downward to the target due to the inclination.