Search

A new nonlinear PID control method is proposed to meet the needs of a vertical robot running under a high speed condition, whose joint transfer function changed with the joints position. Firstly, the experimental system has been set up. Then the joints transfer functions can be established. Moreover, the relationship between the PID parameters and joints angle position θ has been set up by the least square method. So the nonlinear PID controller can be obtained. In the end, several testing experiments have been caught out. The result shows that the nonlinear PID controllers have fast respond, which can meet the satisfaction of the robot under a high speed condition.

A new weld seam detection based on the genetic algorithm has been presented. Firstly, the experimental platform has been setup, and the welding images can be captured by the CCD camera in real time. On this basis, the process region, which is in front of the weld pool, has been determined. Then the median filter has been applied to reduce the disturbance of the noise producing during the welding period. Moreover, the GA has been deeply researched and applied to the weld seam detection. In the end, some experiments have been caught out, and the results show that compared with the traditional Ostu process method, the weld seam images, which are processed by the genetic algorithm, are more clearer and have less noise, which can meet the satisfy of auto welding system.