Coordinated Control of Multi-Fingered Robot Hand Handling an Object in Contact with Environment

为了未来机器人操作手的更广泛应用，开发能够像人类手一样灵活操作的多指机器人手是必不可少的。本研究的目的是(1)建立一种多指机械手的协作控制算法，以同时控制该机械手抓取的与环境接触的物体的相对运动和接触力，以及(2)验证该控制算法的有效性。1.控制算法的建立：将目前一位研究者提出的用于单机器人机械手的动态混合控制方法进行了扩展，建立了一种动态协调混合控制算法。该算法控制物体的位置轨迹、手对物体施加的内力以及ob…之间的接触力。更多的物体和环境同时进行，这样它们就会跟踪所需的位置和力轨迹。三指手的制作：制作了一只有三个手指的手，每个手指都是一个三个自由度的串联连杆机构。手指的总长度是26厘米。设计并制作了安装在每个指尖的小型三维力传感器。手控系统的开发：利用一台32位的个人计算机，开发了手控器和控制软件。实现了4ms的采样时间。控制算法的实验验证：成功地进行了用研制的手的两个手指抓取物体并将其压在平面约束曲面上的初步实验。我们相信，通过上述结果，本研究项目的目的--开发和验证多指机械手操作与环境接触的物体的协同控制算法--已经达到了目的。使用三个手指的实验被留作未来的研究课题。较少

For wider applications of robot manipulators in the future, development of multifingered robotic hands that can perform dexterous manipulation like human hands, is essential. The objective of this research is (1) to establish a cooperative control algorithm of a multifingered robot hand for controlling simultaneously the relative motion and the contact force of an object that is grasped by this robot hand and is in contact with the environment, and (2) to verify the validity of this control algorithm. The results obtained by this research are summarized as follows :1. Establishment of Control Algorithm : Extending the dynamic hybrid control approach proposed by one of the present investigators for single robot manipulator, a control algorithm has been established which will be called the dynamic cooperative hybrid control algorithm. This algorithm controls the positional trajectory of the object, the internal force applied by the hand to the object, and the contact force between the ob … More ject and the environment simultaneously so that they will trace the desired position and force trajectories.2. Fabrication of a Three-fingered Hand : A hand with three fingers, each of which is a serial link mechanism with three degrees of freedom has been fabricated. The total length of the finger is 26 cm. A small scale three-axis force sensor to be attached to the tip of each finger has also been designed and fabricated.3. Development of Hand Control System : Using a 32 bit personal computer, a hand controller has been developed along with control software. A sampling time of 4 ms has been achieved.4. Experimental Verification of the Control Algorithm : Preliminary experiments of grasping an object by two fingers of the developed hand and pressing it against a plain constraint surface have been successfully performed. We believe that the objective of this research project, development and verification of an algorithm for cooperative control of multifingered robot hands in manipulating objects in contact with the environment, has been reached by the above results. Experiment using three fingers has been left as a future research topic. Less