柔性机械手定位系统的研究

【作者】 刘云超；

【导师】 李小京；

【作者基本信息】 天津工业大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 在机械手执行任务的过程中,控制机械手定位到目标位置是一个非常关键的问题,要想对机械手进行有效的控制,首先要对它进行精确的定位。本文采用了距离和图像复合测量的方法对机械手分别进行空间和平面姿态定位。为使超声波测距适应在强干扰工业环境中测量机械手空间位置,采用了互相关原理检测回波信号延迟时间来测量距离的方法。该方法具有很强的抗噪声干扰的性能。为减少计算量并提高离散化的互相关函数分辨率和精度,采用了三点确定抛物线顶点的方法,计算出互相关函数最大值的精确位置,从而确定出回波的时间,使得单次测量空间距离的精度可达士0.12%。提出并验证了在减小采集密度的情况下在离散化的最大值附近,采用三点确定抛物线顶点的方法计算互相关函数最大值是一种具有实时性高、抗干扰性能好的复合测量方法。在机械手平面定位系统中,图像处理是核心部分,本文针对实际的目标图像,通过对其进行图像预处理,再经边缘检测和应用稳健的直线拟合算法求得定位点的坐标和相对偏转角度,获得图像定位的信息。经验证符合设计要求,达到了实际应用的精度。更多还原

【Abstract】 As the robot is implementing tasks, it is essential to control the orientation to object position. Prise orientation is the premise of controlling the robot effectively. The compound measurement of distance and image is adopted for space orientation and plane orientation separately.The paper introduces a method of applying cross-correlation principle to detect the delay time of echo signal. This method has excellent performance in rejecting noise interference. To increase resolution and accuracy of discrete cross-correlation function the method of finding peak point of the parabola by three discrete sample data is used, it can calculate accurate position of maximum of cross-correlation function, thus the return time of echo signal is obtained. And the precision of distance value is up to±0.12%. We present and validate that the maximum of cross-correlation function is confirmed by calculating the peak of parabola through the coordinates of three points. Image processing is the hard-core in the visual orientation system of the robot. In this paper, the practical object image is inputted and dealt with. Through checking the edge of image and applying the least square method, we obtain the coordinates of the anchor point and the relative deflexion angle. It is proved that the result of this design accords with the practical request.更多还原