Intelligent Systems Laboratory

The Lynxmotion Carpet Rover / Lynx 5 Combo Kits are two-wheeled robots with an arm. There is a minor problem from the servos in the kit not being continuous rotation servos. A plastic stop inside each servo has to be cut off and the polarity of the left servo has to be reversed by unsoldering the wires to the motor, flipping them, and then resoldering the wires back to the motor. There were also problems with the gripper being unbalanced and the kit not having enough standoffs to mount both the IRPD and the line following modules. Code was written to test movement with the servos, obstacle avoidance with the IR sensor, line following with the line following module, and picking up an object
with the robotic arm. The servos and the IRPD module were the easiest to test. The line following module seems to be pre-calibrated and relies strongly on having a white surface with a black line. Tests show that the line following module is calibrated to be much too sensitive to the white level that anything even slightly off-white is registered as black. The spacing of the sensors on the line following module is very good for this particular robot, and the middle sensor allows the robot to detect a “T” in the line with great ease.

The arm seemed to be the most complicated Carpet Rover part to program. All the servos for the arm are controlled by a servo controller through a serial input and clock line. Although it is relatively easy to create and send the correct serial
packets to the arm servos, care must still be taken so as not to move the arm in such a way as to damage either the arm or the robot. The next phase is to program the Carpet Rovers to play a simple form of basketball.

(click on thumnail for larger view)