Design of Fuzzy Controller

object of misty ascendancyler for dickens armored combat vehicle interacting brass Mohamed sabith KT Second socio-economic class M. tech Dept of Electrical plan NIT Calicut Calicut, India email&160protected com Dr. Abraham T Mathew Professor, Dept of Electrical Engineering NIT Calicut Calicut, India email&160protected ac. in AbstractThe go out of suave direct in armoured combat vehicles and flow among coolers is a basic problem in the execute Industries. Vital industries such as Petro-chemical industries, Paper making industries, Water discussion industries have the join coolers do workes. The level of fluid in the armored combat vehicles and fundamental interaction in the midst of armored combat vehicles must be obligateled.The aim of the suggest is to model the the coupled ii cooler liquid level establishment and to design a fuzzed accountant. For coupled tank systems with non linear and complex characteristics authoritativeal pelvic inflammatory disease is strong to achieve the desired response. Fuzzy logic control is a classic method by which dynamic performance and strong robustness is guaranteed. The project compargons the performance of the deuce tank system with classical pelvic inflammatory disease and fuzzy logic control. Index Termspelvic inflammatory disease, fuzzy logic, steady state entry through dickens separate pumps whose output is throttled using a control valve.Separate disturbance argon make to both the tanks using hand valves. The devil tanks are connected by means of hand valve, so the level of tank 1 allow affect the tank 2 and guilt versa. So this is a bluely non linear system. Flow transmitters and pressure transmitters are there which give indication of flow and level respectively in a scale of 4-20 mA. The commentary from this sensors are taken to a electronic computer which is process by a software in which controller is use which will give necessary control signal to throttle the control valve t o get the necessary level.A joined tanks process is found in the many an(prenominal) industries. Generally, The TITO processes have the problems to control their systems because of the existence of interactions between stimulant drug and output variables. umpteen control methods such as 2DOF PID 1, Auto tuning PID 2, CDM 3 and De match 4 have been applied to coupled tanks processes for solving their problems. This melodic theme presents control of two tank interacting system with the help of classical PID and Fuzzy control. The paper is organized as follows.The next section gives details about Coupled-tank process. partitioning 3 explains about modeling of two tank interacting system. Section 4 explains PID based control. Section 5 explains an implementation of Fuzzy restrainer for coupled tank process. Section 6 shows experiment process and results. Finally, conclusions are given in section 7. COUPLED TANK SYSTEM imitate OF A TWO TANK INTERACTING SYSTEM Consider the coupled tank, two-input two-output process . The target is to control level of two tanks by the inlet piss flow from two pumps P1and P2.The process inputs are flow rate of two pumps u1(t)and u2(t) which is throttled using control valves. The nonlinear plant equations can be obtained by mass balance equation The overall material balance on the cylindrical tank is Rate of mass accumulation in the system = rate of mass entering in the system- rate of mass going the system There for the dynamics of the tank system can be written as The coupled tank apparatus is shown in the practice 1. 1. The apparatus is a model consisting of a pump, two cylindrical tanks made of plexiglas, two control valves, and two level transmitters .The two tanks are installed in a manner as shown in the common fig tree 2. 1The water input to both the tank is provided ??????? 1 ?????? ?????? 1 ?????? = ? ?????? 1 ?????? ? ?????? 1 ? 2 ? ?????? ? ?????? 1 ?????? + ???????????? ???????????? ?????? ?????? ?????? ? ( 2 ? ?????? ? ?????? 2 ?????? ? (2 ? ?????? ? ?????? 1(?????? ) ?????? ??????? 2 ?????? ?????? 2 ?????? = ? ?????? 2 ?????? ? ?????? 2 ? 2 ? ?????? ? ?????? 2 ?????? + ???????????? ???????????? ?????? ?????? ?????? ? ( 2 ? ?????? ? (?????? 1 ?????? ? 2 ? ?????? ? ?????? 2 ?????? ??????Where A is the cross section area of tank 1 and tank 2, a is the cross section area of outlet hole of tank 1and tank 2 and cross section area of jointed pipe between tank 1 and tank 2 , ? 1 is the valve ratio at the outlet of tank 1, ? 2 is the valve ratio at the outlet of tank 2, ? x is the valve ratio between tank 1 and tank 2. k1,k2 are the gain of the pump. The above equations can be converted to transfer die hard form and a transfer matrix of the form is obtained. ?1(?????? ) ?????? 11(?????? ) ?????? 12(?????? ) = ? 2(?????? ) ?????? 21(?????? ) ?????? 22(?????? ) ?????? 1(?????? ) ?????? 2(?????? ) nteraction between processes, the control design needs the decoupling controllers to minimize the cro ss coupling effects Because of the interaction between processes, the control design needs the decoupling controllers to minimize the cross coupling effects The decoupling controllers consist of two disconnectrs d12 and d21 . The purpose of using decouple is to decouple the multivariable system. This can be done by choosing the following transfer function. D21=-G21/G22 D12=-G12/G11 SIMULINK manakin OF COUPLED TANK SYSTEM WITH PID CONTROL AND DECOUPLERS The modeled coupled tank system was simulated using simulink .G11 represent the dynamics of the tank 1 ,similarly G22 represent the dynamics of tank2. G12 represent the effect of level of tank 2 on tank1,and G21 represent the effect of level of tank 1 on tank 2. Due to high interaction between the tanks ,its concentrated to control with ordinary PID. So as to avoid the interaction Decouplers were introduced. The expediency with the decoupler is that separate PID controllers can be designed for individual loops. devil individual P ID controllers were designed for the two loops and tuning of the controllers were also performed. tank car 1 is subjected to a setpoint input of 15cm at clock of 30 heartbeats and it is having an setpoint of 5cm. Similarly Tank 2 is subjected to a setpoint input of 25cm at time of 50 seconds and it is having an sign setpoint of 10. The response of the simulated system is shown in fig down the stairs,both the level of tank 1 and tank 2 follows the setpoint with small apex of the suns way overshoot. Where h1, h2 are the liquid level in two tanks and u1,u2 are the input into the two tank . Where transfer matrix Gij(s)has the value as following G11(s)= ?????? 1 ???????????? +?????? 2 ?????? + ?????? ?????? 2???????????? ?????? 1???????????? +?????? ?????????????????? +2?????? 1?????? 2 1 1 1 ?????? 2 + ?????? +( + + ) ?????? 1?????? 2???????????? ?????? 1?????? 2 ?????? 1???????????? ?????? 2???????????? G22(s)= ?????? 2 ???????????? +?????? 1 ?????? + ?????? ?????? 1???????????? ? ????? 1???????????? +?????? 2?????????????????? +2?????? 1?????? 2 1 1 1 ?????? 2 + ?????? +( + + ) ?????? 1?????? 2???????????? ?????? 1?????? 2 ?????? 1???????????? ?????? 2???????????? ?????? 2 1 ?????? ???????????? ?????? 1???????????? +?????? 2?????????????????? +2?????? 1?????? 2 1 1 1 ?????? 2 + ?????? +( + + ) ?????? 1?????? 2???????????? ?????? 1?????? 2 ?????? 1???????????? ?????? ???????????? G12(S)= G21(S)= ?????? 1 1 ?????? ???????????? ?????? 1???????????? +?????? 2?????????????????? +2?????? 1?????? 2 1 1 1 ?????? 2 + ?????? +( + + ) ?????? 1?????? 2???????????? ?????? 1?????? 2 ?????? 1???????????? ?????? 2???????????? Design of Decouplers The theoretically modeled system was simulated using simulink as shown in fig. down the stairs . G11(s) represents the tank 1 and G22(s) represents the tank 2. The effect of tank 1 on tank 2 is given by G21(s) and the effect of tank 2 on tank 1 is given by G12(s). This coupled tank system is having high interaction and it also exh ibits non linear characterstics.Because of the The input variable wrongful conduct(e) is shown below,for all these inputs louver membership functions are employ. The five membership functions are NB,N,Z,P,PB. Fuzzy controller The traditional control, which includes the classical feedback control , has encountered many difficulties in its applications. The design and outline of traditional control systems are based on their precise mathematical models, which are usually very difficult to achieve owing to the complexity, nonlinearity, time varying and incomplete characteristics of the existing practical systems.One of the most effective shipway to solve the problem is to use the technique of intelligent control system, or hybrid methodology of the traditional and ntelligent control techniques. The output variable is shown below As i have 2 inputs with 5 membership functions,I used 25 rules(IF THEN ). The surface of the rulebase is as shown below The above fig shows how a fuzzy c ontroller is implemented . The Fuzzy controller takes two input and have one output, error and rate of swop of error are given as input to the fuzzy controller . depending on the input the fuzzy controller produces required control action.For all input and output triangular membership functions are used. The input rate of change of error(de) is shown below The two tank system with fuzzy controller is subjected to an input,the first off tank is set to a initial level of 5cm then it is subjected to a step change of 15 cm at 25 seconds,for the second tank it is set to a initial level of 10 cm and final level of 20 cm. With fuzzy controller the outputs obtained is as shown below 1 Suparoek Kangwanrat1, Vittaya Tipsuwannaporn ? Design of PI experienceler Using MRAC techniques for Coupled-Tanks Process? International congregation on Control, Automation and Systems 2010 Oct. 7-30, 2010 in KINTEX, Gyeonggido, Korea 2 V. R. Ravi , T. Thyagarajan ? Application of Adaptive Control Techniq ue to Interacting Non Linear Systems IEEE Transactions On Systems, Man, And CyberneticsPart B Cybernetics, 33( ), 2003, 514521 3 3 Dr. S. AbrahamLincon, P. Selvakumar ? Design of PI Controller using Characteristic Ratio Assignment manner for Coupled Tank SISO Process? International Journal of Computer Applications (0975 8887) Volume 25 No. 9, July 2011 4 Li LIANG ? The application of fuzzy PID controller in coupled-tank liquid-level control system?IEEE Transactions on Industrial Informatics, vol. 6, no. 1, pp. 25-35, 2010 5 Jutarut Chaorai-ngern, Arjin Numsomran, Taweepol Suesut, Thanit Trisuwannawat and Vittaya Tipsuwanporn ?PID Controller Design using Characteristic Ratio Assignment Method for Coupled-Tank Process.? Proceedings of the 2005 International Conference on Computational Intelligence for Modelling, Control and Automation CONCLUSION The output obtained for fuzzy controller doesnot show peak overshoot as in th case of a PID controller ,the problem observed with fuzzy con troller is that small oscillations will be prescent at steady state REFERENCES