The Study On Control Flexible Robot Hand System Based On Hydraulic Drive

Hands are essential organs of human. Losing of hand caused by various reasons will do harm to people both in physical and psychological seriously. However, as two treatments of losing hand, limb replantation and installation of artificial limbs developed in their respective fields separately as if two parallel lines, but both failed to meet the requirements of patients in function and appearance. To be able to clone the missing structure and function of the hand has always been the dream of human. The idea of implantable prosthetic hand make this dream possible to be achieved. This idea aims to provide a kind of implantable artificial hand that is multi-function, zero error rate and no complications, and make it a part of human body through surgery.Robot hand in real life play an increasingly important role.Practical application of today's robot hand with a simple majority of the end implement to clamp workpiece.they are design for special assignment or special workpiece clamped.With the development of the manufacturing sector, the production process requires not only automatic, but requires a flexible robot hand. In some aspects of this trend was more and more obvious, such as automatic assembly lines in a number of others have been replaced by manual assembly,The main reason is the lack of the necessary flexibility in automation, can not be well adapted to rapidly changing market requirements.Human hand can do almost all the work of the production process, while the robot hand is far to do this. Therefore improve the performance of manipulator control in order to increase its flexibility is necessary. Study on Control Flexible Robot Hand System, The ability to comply the environment called flexibility. To resolve this contradiction, robot experts made a great deal of research, known as the soft control. This article is design Control Flexible Robot Hand System Based on Hydraulic Drive.With the micro-electronics technology and advanced control algorithms by the introduction of hydraulic servo system.This create a new development area for miniature, smart, flexible manipulator control system.Flexible robot advantage than the rigid robot manipulator,Lightweight structure and a long lead over the size of robot is very flexible, making the control of flexible manipulator and modeling become a challenging issue. Main reasons: first, flexible with a high hand and low placement of the oscillation damping, control the process prone to elastic deformation and vibration; Second: soft hand is infinite-dimensional distributed parameter systems, because of computers, sensors and systems of non-precision noise, similar to commonly used low-end system can easily lead to "overflow control" and "measurement overflow." Under certain conditions, the overflow will lead to system instability. Third soft hands, drives and sensors are usually non-bit configuration, the system under the influence of the flexible input / output causal relationship was non-minimum phase characteristics. Fourth: soft hand is a highly complex highly nonlinear, highly coupled nonlinear time-varying systems. In addition to its nonlinear coupling includes joint angle and its derivative, but also including the flexible generalized coordinates and joint angle of the coupling. In order to solve these difficulties, we need to set up a reasonable system of control and selection of appropriate control algorithms designed to meet the control requirements of the controller.In this paper, control of flexible manipulator in this article do the following work: 1. This chapter from the flexible manipulator mechanical structure, the analysis of the characteristics of a single bending joints, the establishment of a three-joint finger dynamic model and kinematics model of the location of the fingers being analyzed, and reverse the movement of all joints point of view is optimized, an analysis of the dynamic model of a finger. The use of recursive methods to derive the key points of the velocity and acceleration. The final plan based on the 3-4-5 polynomial finger exercise on the planning machinery.2. By analyzing the joint position electro-hydraulic proportional control system for the various components of the composition and working principle, the establishment of a voltage signal input from the hydraulic cylinder displacement of the closed-loop mathematical model of the output of the hydraulic system to the implementation of the mathematical model, and Matlab / Simulink closed-loop system for the transfer function analysis. Mainly on the system stability and response characteristics of the study can be seen from the simulation curve, the system stability, and response curve without fluctuations in the transition process, however long, there are static error, the need for further improvement, namely the need to increase links correction3. In the ratio of electro-hydraulic system, respectively, the application of fuzzy PID control algorithm and simulation analysis algorithm. We can see through the simulation analysis, PID control algorithm and fuzzy control algorithm can be achieved certain results. PID algorithm is simple and generic, fuzzy look-up table method needs some experience, if the choice of reasonable parameters, it is more effective than PID control algorithm, and that they do not have the best control effect.4. In the fuzzy control algorithm based on genetic algorithm to optimize, and then based on genetic algorithm optimized fuzzy PID controller for the electro-hydraulic proportional system simulation, simulation results show that the stability and accuracy of control than the conventional PID control and fuzzy control have good control effect.5. The force control of the fingers, respectively, the application of impedance control algorithm and adaptive algorithm of the simulation of a wide range of conditions studied and under the same conditions in their analysis of performance comparison. Study shows that the traditional method of adjusting the impedance of the whole time adaptive impedance algorithm more quickly, but its control performance is not as good as the accuracy of self-adaptive algorithm; adaptive control algorithm in a relatively harsh conditions (environmental stiffness up with other changes in the location at the same time ) has managed to maintain a very precise force control, and it can be tracked to a specific force. Therefore it is more suitable for accurate dynamic model of manipulator, environmental conditions, such as more complex case of force control algorithms, with higher application value.