Summary: | 碩士 === 義守大學 === 電子工程學系 === 107 === Line following is very common in robotics competition. Controlling a robot to move along a smooth line looks like simple enough for a kid to learn the programming. However, it may be quite difficult in some conditions. For example, if the line has sharp corners, the robot usually is easy to missing the line. Even worse, if high-speed line following is required, the momentum, linear and rotational, will be the hardest work to overcome. This work applies part of traditional PID control method to achieve high-speed line following robot with a fine tuned P coefficient and an adaptive D coefficient. However, we found the I-term is useless for irregular line pattern. Therefore, it is not included in this control mechanism. Further, we use a Gyro sensor to control the robot toeing the line quickly because it simply measures the rotation speed of the robot. Since the rotational momentum is proportional to the rotation speed, a proportional anti-momentum is applied to reduce the rotation speed of the robot quickly. Therefore, the method is called PDG control. The robot has been implemented with a low cost Arduino Mega 2560, two DC motors, a light sensor array with 6 lights, and a few Lego parts to assembled. Several experiments has been done with different line patterns. Results show that our robot is reliable and can achieve the speed over 100cm/s easily. Notably, we have verified our robot in several national robot competitions, and won quite a few awards.
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