TAP CHi KHOA HQC & C N G N G H $ CAC TRU'6NG D^I HQC K V THUAT * S6 86-2012 ( APPLYING NEURAL NETWORK TO CONTROL 4DOF TELE - OPERATION MANIPULATOR U'NG DUNG MANG TIMN KINH NHAN TAG TRONG DIEU KHIEN TAY MAY BAC TV' DO HOAT D O N G TU' XA Tu Diep Cong Thanh Ho Chi Minh City University i>f Technology Received May 16 ,2011 ABSTRACT Almost all interactive problems between humans and the unsafe environment such as dangerous, toxic, infectious or sterile in the world can be solved by robot technology In particular, one of feasible and stability solution is Tele-Operation Manipulator Technology By using Ihe master manipulator to record the movements and behaviour of Ihe driver in a safe environment, then transmits these parameters over a LAN to the slave manipulator which is controlled in the toxic, hazardous or sterile environments and strictly comply with people's behaviour is proposed in this paper Keywords: Tela-operation, Control, LAN TOM TAT Hau het cdc v§n dS tuvng t^c giifa ngutri va cdc moi tn/ong nguy hiem, dgc hai, lay nhiem ho$c v6 trung diu di/pc g/d/ guyM bSng ky thu$t robot Trong dd, mgt nhung giai phap mang tinh kha thi, on dinh va tri/c quan nhit la ky thu$t Tele-Manipulator BSng each su" dung tay may tuxmg tir de ghi nhan cac chuyen dong va hanh vi cua ngutri diSu khiSn moi tnjong an toan, sau truyen cac thong so ndy qua mang LAN cho tay may chinh thuc hi$n dung theo hanh vi cua nguui didu khidn moi truing ddc h^i va nguy hiSm ho$c vd trung la huung nghien cuu dd xuit tmng bai bao TLT khoa: Hoat dong tu- xa, Dieu khien, Mang LAN L INTRODUCTION Tele-Operation Manipulator (TM) system is a remote control manipulator consists of two arms: the master and slave Slave manipulator is controlled to perform the same motion as master manipulator To implement this control, master manipulator is controlled by human The desired motion of the master manipulator is recognized by sensors and these values is transmitted via LAN lo the slave manipulator controller In 1898, Nikola Tesia made boat control model using radio in New York first to now, the TM has a history of development over a century [1] TM system as the first true master - slave is made a pure mechanical structure is benevolent R Goertz late in 1940 at the National Laboratory Argone [2] In 1954, R Goertz system development operations with the first electro-mechanical servo controller With the development of more modem techniques, the TM system appear in many areas more efficient service lo people such as explosives detection arm of national defense and arm on the spacecraft, hand-picking machine of nuclear fuel in nuclear power indushy and especially the type of ann surgery in remote health One of the outstanding research of robots for medical applications is manipulator system tor remote microsurgery institute KAIST, Korea [3] and surgical manipulator system accuracy in medicine at the University of Washington, USA [4] TM control to execute as well as the ability to monitor and respond in real time, a number of studies related to model algorithms and system control are presented, such as adaptive control using a slide control algorithm is presented by Plato [5], techniques to reduce transmission time over the network in conttol TM suggested by Lee [6], Sano technical proposal in the time delay compensation control T ^ P CHi KHOA HQC & CONG NGHE CAC T R U N G BAI HQC KY THUAT * S 86 - 2012 TM [7], with Towhidkhah modeling and predictive control [8], and robust control with random time delay proposed by Prokopiou [9], etc In this study, a tow cost TM system is presented A newly proposed neural network controller is applied to control four degrees of freedom (4D0F) manipulator via LAN Results obtained will be presented through experiment receives the responese of 4DOF TM To control slave manipulator, PC server will compute the control signals and send these signals to low cost circuit using PIC 18F4450 through PC client via LAN Control software is coded based on C#, and the phoptograph of experinental system is shown in figure II EXPERIMENTAL SETUP The overview of system and schematic diagram of system are presented in figure I and figure respectively Fig Photograph of apparatus CA - 1^, ^s., Fig I Overview of the proposed TM system the experimental HI CONTROL SYSTEM The overall of control system is shown in figure To improve control performance, neural network controller is proposed The structure of the newly proposed control algorithm using neural network is shown in figure The input layer has three neurons There are six neurons in hidden layer All layers are connected in only the forward direction Wellknown steepest descent learning method is applied for online adaptive control The input to each neuron is given as the weighted sum of outputs fi-om the previous layer The output of each neuron is generated by linear function in the input layer In hidden and output layers, the sigmoid function is used And the structure of neural network is shown in figure Fig Schematic diagram of system The system includes master manipulator is controlled by human and enforce slave manipulator motion the same with the master manipulator motion Parameters of motion of the master manipulator are recognized by the encoders (USDigital S5 Optical 1024R/P) and sent to PC server (computer 2.4 Ghz Pentum IV) through PCI 1874 circuit PC server transmits these informations to the PC client via LAN (computer Pentum IV 2.4 Ghz) as well as /.—(-^) = (1) To construct learning rule, the following symbols are defined: / ' : Input to the jth neuron in the input layer o' :Output from the jth neuron in the input layer /" : Input to the kth neuron in the hidden layer of :Output of the kth neuron in the hidden layer /^: Input to the output layer TAP CHi KHOA HQC & C N G NGHJ: CAC T R U I N G D^l HQC K t THU^T * S 86 - 2012 " : Output from the output layer The operation of each neuron is described as: cOji, : Weight from the jlh neuron in the input ";='•; (2) layer to the kth neuron in the hidden layer Q)"": Weight fi-om the kih neuron in Ihe hidden layer to the output layer "/'=./.„ ,0i'] / i ' = K o j / o" = A,, ,{i"l (3) /'•'=X'""V