This research paper presents design of a gripper finger mechanism and a new curvature measurement method of fingertip trajectory. Firstly, the conditions of a grasp provided by gripper, which was designed from a spherical mechanism, was explained. Therefore, trajectory length of coupler point was modeled as objective function which is maximized. Ball-Burmester theory was used to form constraints which can provide a spherical curve with curvature close to zero. A plausible dimension range of mechanism, transmission angle, instantaneous invariants were arranged as constraint function. A meta-heuristic algorithm previously developed by one of authors was used to search the best instantaneous invariants based on the type of mechanism. The optimal solution was prototyped, and three-fingered gripper assembled. Secondly, an endoscopic camera peculiarly was used to measure curvature of the trajectory traced by coupler point of an optimal four-link spherical mechanism which was supposed to compose a finger of a robotic gripper. The coupler of the mechanism was expected to trace approximately a great circle arc to provide a grasp. Therefore, the technique to measure curvature was based on image processing and geodetic curvature theory. A calibrated endoscopic camera was used for acquisition of video record above the prototype which was centered in the center of the camera screen. The curvature of coupler point of optimal spherical mechanism design and prototype were compared. According to performed regression analysis, results of the measurement were %97 reliable for the useful part of the trajectory.

该研究论文提出了一种夹爪手指机构的设计和一种指尖轨迹的曲率测量新方法。首先，说明由球形机构设计的抓爪提供的抓握状态。因此，耦合点的轨迹长度被建模为最大化的目标函数。Ball-Burmester理论用于形成约束，可以提供曲率接近零的球面曲线。合理的机构尺寸范围，传动角度，瞬时不变量被安排为约束函数。由一位作者先前开发的元启发式算法用于根据机制类型搜索最佳瞬时不变式。最佳解决方案被原型化，并安装了三指式抓爪。其次，特别地，使用内窥镜照相机来测量由最佳四连杆球形机构的耦合点所描绘的轨迹的曲率，该最优四连杆球形机构被认为是机器人抓手的手指。预期该机构的耦合器会追踪大约一个大的圆弧，以提供抓地力。因此，曲率测量技术是基于图像处理和大地曲率理论的。使用校准的内窥镜摄像机获取原型上方的视频记录，该原型位于摄像机屏幕的中心。比较了最佳球形机构设计和原型的耦合点曲率。根据进行的回归分析，对于轨迹的有用部分，测量结果可靠度为％97。