Research On Grasp Control Of The Prosthetic Hand Based On Tactile Sensor

Anthropomorphic prosthetic hand is an important tool for the amputees to regain theability of hand. It is of great significance to study it. Funded by the National Key BasicResearch and Development Program (973Project)“Design Manufacturing andPerformance Evaluation of the Sensory-integrated Operational DexterousProsthesis”(NO.2011CB013306), this dissertation designs the prosthetic hand controlsystem and studies the impedance control of single finger and the stable grasping ofmulti-finger based on the HIT V anthropomorphic prosthetic hand with the purpose tohave a better humanoid capability.The humanoid mechanical structure of prosthetic hand provides the basic humanoidathletic ability. But how to make it complete the humanoid movements, the key problemis the design of the control system. This paper designed a modular, integrated controlsystem based on FPGA. It consists of ten modules. The master control module is the corechip to generate the control algorithm and communicate with other modules. The fingercontrol module can independently complete its control task and it is integrated withposition sensors, torque sensors, tactile sensors and so on. The EMG module andelectrical stimulation module provide a two-way communication channel withamputees. The control system is integrated in the prosthetic hand through the smallpackage chips and hard and soft circuit board.In the grasping of human hand, the position and grasp force of finger can be freelycontrolled. In order to make the prosthetic hand have the ability of position control andforce control, the impedance control of single finger has been studied. Impedance controlexperiments based on tactile sensor and torque sensor were conducted to compare theireffect on the single finger control. At the same time, an adaptive force-tracking controlalgorithm based on impedance control has been proposed. And the force-trackingexperiments have proved its good proformance.When object slips caused of outside disturb and object gravity changing, humanhand can change the posture and force to let the object remain stable. In order to achievethe stable grasping, the Frictional Vibration during the process of slip has been studied,and a slippage detection based on the energy spectrum of the tip force has been proposed.Then design a stable grasping control strategy and conduct the comparative experimentwith direct control without stable grasping control strategy to prove its effectiveness.