This process of continual improvement and innovation yielded some terrific contraptions. We will be entering two robots in the walking competition, a six legged and four legged model. We will be entering a fantastic table clearing robot with mechanical arms that literally launch the cans off the table instead of just pushing them. At least three speed robots will compete, each using specific gear ratios to obtain the perfect balance of torque and top speed. Two weight-pulling robots will compete, one of them using two full cans of soda as ballast. A slope climbing robot has consistently climbed 60˚ without incident. And two delivery robots will compete.
The delivery mission is probably the most difficult challenge at the Track Meet. A robot has to navigate a course with walls and black and blue tape lines, either dropping its cargo on target #2 (longer, but easier), or launching it through target #1 (shorter, but more difficult). Being successful at this challenge depends on both solid physical engineering and clever programming.
I just love the perseverance and creativity that LEGO robotics brings out in kids. Their dogged determination plus a tip from an underclassman paid off.
Later that day, I shot video of another delivery robot built and programmed by an 8th grader at Woolwich Central School. She used a combination of reflective light sensing, distance sensing with the ultrasonic sensor, and motor sensing to record the number of rotations completed. A different approach to solve the same problem.
Debugging this program was a bear. The motor rotation sensor didn't seem to be working, and we couldn't figure out why. Then it hit me. We were asking the robot to stop after 8 rotations at the end of the program, but by they time it got to that part of the program, the motor had already turned tens of times. We needed to insert a block to reset the motor rotations to zero before entering the last part of the program. It worked!
Another 8th grade team from Woolwich designed this amazing four-legged walking robot.