Improving grasp capabilities of KNTU hand using position & force sensors

Abstract

This paper presents the recent developments in the newly proposed KNTU robotic hand for improving its grasp capabilities as a dexterous robotic hand. This hand has three fingers (two 2-link fingers and a continuous one) that has the ability to grasp objects with different shapes. Each rigid finger is made up of two rigid links which are driven by cables connected to the motor. Also, both rigid fingers are installed on a rotary base which can configure them with respect to the continuous one that has a fixed base. The continuous finger is controlled by three cables, each of them is connected to a separate motor. So the robotic hand has eight motors. This paper will describe the grasp planning for various objects by this robotic hand. First, an initial grasp configuration is planned according to the robotic hand structure with a good assortment of geometric shapes of objects. Four potentiometers on the links of rigid fingers are used for position control, also three encoders for continuous finger. Next, seven FSRs are used to measure the interactive force at the contact point in order to recognize the contact between the object and fingers. The microcontroller receives all the data to make a position control for all fingers. Finally, the proposed feedback control system is implemented and obtained result sare discussed.