Visual Trajectory Tracking With Improved Chain Code

Trajectory tracking for robot is a classical application in the controlled filed used by vision-guided robot, and is of great theoretical and practical significance. Trajectory always refers to straight line or space curve, so the key problem for trajectory tracking is image processing and providing information of the curve tracked to the motion control system. In this paper, the following researches are done on trajectory tracking technology for armor plant.1. Build location-based visual servo controlling system. There are two subsystems in the controlling system: the visual inspection subsystem based on the triangulation principle and movement controlling subsystem composed by rectangular coordinates robot and movement controlling card. Moreover, calibrate for CCD sensor of the measurement system and rectangular coordinates robots are completed.2. The image processing algorithm used in the vision tracking system is designed. Self-adaption threshold value algorithm is proposed according to the differences of light to the image gathered on site. And the centerline of the curve is obtained by the method of searching line-by-line and column by column.3. The principle of chain code is used on curve tracking, According to the principle that vectors of improved chain code can't arise a break between two adjacent feature points on the curve; the next feature point on the tracking edge can be found. In order to get the disperse dot series of the curve's centerline. Though the automatic adjustment. The time of tracking curve is shortened and the interrupt part of the curve's characteristic dot is connected.4. The object-oriented programming techniques are used in this paper. The function of image processing, getting the center line and tracking with improved chain code is achieved by C++ under VC6.0 environment. It provides 3D coordinate value of the tracking curve to motion control system.Through the curve tracking experiments research, the tracking system can fully meet the target and well solute kinds of interference problems.