by Dr. K C Cheung, Mechanical Engineering
Jul 4, 2016
Robocon is an annual robot contest with participating teams from HKU, HKUST, CUHK, Poly U, City U and IVE (Tsing Yi). This year's contest theme is quite special. A robot has to go up a ramp, navigate some bends, and go down a meandering slope without any power source to drive its wheels. The power has to come from another robot by non-contact means. Most teams used ducted fans to blow onto sails. One team, from City U, used remote charging technique to charge up the capacitors which then powered the robot's motors.
HKU entered two teams in the contest. One of the teams got to semi-finals with another one going through till the third-fight. During test runs on our own game field, we did a best-time of 38 seconds.
After the contest, our students performed a review to work out why the robots could not deliver the same performance in the contest. One of the reasons was that that the lighting condition of the contest field was very different from that in our test run site. We used fluorescent lamps but bright spot lights were used in the contest field. Probably this caused saturation in our optical sensors that looked at the white lines on the tracks. Another "self-inflicted" problem is due to our robot trials. As can be seen from the video, the robot with the ducted fan had to pick up the propeller and go up a pole in order to place the propeller onto the hub. On this robot, we fitted two clamps that pressed hard onto the pole in order to ensure a good grip. However, the reaction of the clamping force deformed the chassis of the robot. When we approached the contest day, we found that the chassis was so deformed that the encoders that we used to measure the displacement of the robot on the game field could not maintain reliable contact with the floor.
One final note. The team took the "Best Artistic Design Award". Congratulations!
