Robot¶
The robot platform is based on a heavily customized ROX with differential drive. Even though it looks very different, most information about operation, safety and maintenance are still applicable. This page will focus on the differences and additions.
Kinematics¶
The robot has a differential drive kinematics, which means it can move forward/backward and turn on the spot with the rotary center between the traction wheels.
In idle mode and when powered off, the robot closes its brakes. The brake release button can be used to open the brakes and push the robot manually. Since the brakes need power, at least the battery must be switched on for this. Note that manual brake release during operation is considered a safety incident which must be confirmed afterwards by briefly turning the key switch (when the LEDs blink blue).
Sensors¶
The robot features a safety laser scanner to detect obstacles by measuring distances. If an obstacle gets too close to the robot while driving automatically, it will slow down and eventually stop and wait until the obstacle is removed. Teleoperation is still possible however. If the obstacle gets close enough to penetrate the scanner’s safety field, the safety controller will inhibit any movement in a safe way (yellow LEDs). The only way to move the robot from here is the brake release button.
Tipp
- Any macroscopic object can be recognized as an obstacle, for example loose wires, grass or uneven floor.
- Laser scanners have been known to be sensitive to direct sunlight or abrupt changes in lighting. Check the scanner display for error messages.
Achtung
The robot does not have a way to detect holes or cracks in the floor. It is the operator’s responsibility to ensure a safe environment. Dropping more than a few centimeters can damage the robot.
XY Table¶
The XY table consists of two linear axes mounted perpendicularly to allow for precise fine positioning.
When the robot arrives at a destination point, the table will first move to two reference points, read their absolute positions and then calculate the required fine position and move the tool there.
Tool axis¶
The tool axis contains the prism and the tool, mounted on top of one another.
The tool axis is attached to the robot with a quick-release fastener. To switch the tool, unplug all cables, open the lever and pull the axis up and sideways away from the robot. Then attach the axis with the new tool, close the lever and plug all necessary cables back in.
Before using the tool, make sure to enter the correct tool and prism offsets in the user interface.
Inclination¶
The inclination sensor enables the robot to calculate the tool position even on uneven surfaces. The sensor must be mounted in the correct orientation, i.e. „X“ axis forward and „Y“ axis to the left. Refer to the diagram printed or engraved on the sensor.