Wenzhen Yang

A Parametric Modelling Method for Dexterous Finger Reachable Workspaces

The well-known algorithms, such as the graphic method, analytical method or numerical method, have some defects when modelling the dexterous finger workspace, which is a significant kinematical feature of dexterous hands and valuable for grasp planning, motion control and mechanical design. A novel modelling method with convenient and parametric performances is introduced to generate the dexterous-finger reachable workspace. This method constructs the geometric topology of the dexterous-finger reachable workspace, and uses a joint feature recognition algorithm to extract the kinematical parameters of the dexterous finger. Compared with graphic, analytical and numerical methods, this parametric modelling method can automatically and conveniently construct a more vivid workspaces forms and contours of the dexterous finger. The main contribution of this paper is that a workspace-modelling tool with high interactive efficiency is developed for designers to precisely visualize the dexterous-finger reachable workspace, which is valuable for analysing the flexibility of the dexterous finger.

Control System Design of the YWZ Multi-Fingered Dexterous Hand

The manipulation abilities of a multi-fingered dexterous hand, such as motion in real-time, flexibility, grasp stability etc., are largely dependent on its control system.This paper developed a control system for theYWZ dexterous hand, which had five fingers and twenty degrees of freedom (DOFs). All of the finger joints of the YWZ dexterous handwere active joints driven by twenty micro-stepper motors respectively. The main contribution of this paper was that we were able to use stepper motor control to actuate the handʹs fingers, thus, increasing the hands feasibility. Based the actuators of the YWZ dexterous hand, we firstly developed an integrated circuit board (ICB), which was the communication hardware between the personal computer (PC) and the YWZ dexterous hand. The ICB included a centre controller, twenty driver chips, a USB port and other electrical parts. Then, a communication procedure between the PC and the ICB was developed to send the control commands to actuate the YWZ dexterous hand. Experiment results showed that under this control system, the motion of the YWZ dexterous hand was real-time; both the motion accuracy and the motion stability of the YWZ dexterous hand were reliable. Compared with other types of actuators related to dexterous hands, such as pneumatic servo cylinder, DC servo motor, shape memory alloy etc., experiment results verified that the stepper motors as actuatorsfor the dexterous handswere effective, economical, controllable and stable.