Current-mode singleton fuzzy controller

CURRENT-MODE SINGLETON FUZZY CONTROLLER I. Ba u one, S. Sánchez Solano, J. L. Hue as Ins i u o de Mic oelec ónica de Se illa - Cen o Nacional de Mic oelec ónica A da. Reina Me cedes s/n, (Edi . CICA) E-41012, Se illa, Spain 3 d. In e na ional Con e ence on Fuzzy Logic, Neu al Ne s and So Compu ing (IIZUKA’94), pp. 647-648, Iizuka - Japan, Augus 1-7, 1994. This ma e ial is p esen ed o ensu e imely dissemina ion o schola ly and echnical wo k. Copy igh and all igh s he ein a e e ained by au ho s o by o he copy igh holde s. All pe sons copying his in o ma ion a e expec ed o adhe e o he e ms and cons ain s in oked by each au ho ’s copy igh . In mos cases, hese wo ks may no be epos ed wi hou he explici pe - mission o he copy igh holde . Abs ac .-- This pape desc ibes he ealiza ion o a uzzy con olle which implemen s he simpli ied in e ence mechanism. CMOS analog ci cui s whe e signals a e ep esen ed as cu en s a e employed. Howe e , he whole sys em is ex e nally communi- ca ed h ough ol ages, hus enabling simple in e - ace wi h con en ional con ol ci cui y. I. INTRODUCTION The e icien ealiza ion o mic oelec onic sys ems o uzzy logic-based con ol applica ions equi es a ca e ul choice o bo h he in e ence mechanisms and he ci cui s uc u es which implemen each con olle block. Among he a ious in e ence me hods, he sin- gle on o simpli ied me hod is he mos adequa e o ha dwa e implemen a ion, as well as o e ing enough eedom in he choice o an eceden s and consequen s o ensu e e icien con ol. Conce ning ci cui design me hodologies, cu en -mode echniques a e espe- cially sui ed o di ec implemen a ion o he basic uzzy ope a o s. Wo king in cu en -mode, dynamic ange p oblems can be handled wi h enough lexibili y and a high-speed ope a ion can be a ained. Ano he impo an ea u e wo h conside ing is he con olle ’s compa ibili y wi h exis ing de ices. The elec ical a iable (ei he ol age o cu en ) ha senso s (ac ua- o s) p o ide (accep ) imposes a limi a ion o he design echnique o be chosen. In his sense he p o- posed con olle wo ks wi h ol ages a inpu and ou - pu o main ain compa ibili y wi h con en ional ol age con ol ci cui s. Finally, con olle p og am- mabili y is essen ial since i limi s he con olle adap - abili y o sol e di e en con ol p oblems wi hou demanding complex adjus men p ocedu es. II. CONTROLLER ARCHITECTURE The simpli ied in e ence mechanism can be consid- e ed as a pa icula case o hose which a e p oposed in [1]. Howe e , i s implemen a ion cos is much less as can be deduced om Fig. 1. The only building blocks a e membe ship unc ion gene a ing ci cui s o desc ibe he an eceden s o he di e en ules, Min o Max ope a o s o implemen he connec i es be ween hese an eceden s, and a ule ponde ing block (consis - ing o a cu en mi o and a di ide ci cui ) o ul ill he exp ession: In wha ollows he ealiza ion o each block in Fig. 1 is p esen ed. A. Membe ship Func ion Ci cui (MFC) The MFC blocks o Fig. 1 gene a e he membe ship unc ions o he di e en an eceden s. The o m and loca ion o hese unc ions a e de e mined by a se ies o pa ame e s, which allow choosing iangula o ap- ezoidal unc ions wi h di e en slopes. A ol age o cu en con e o p o ides he cu en Ixi p opo ional o he inpu ol age. The g oup o med by he ansis- o s M1, M2 and he block cN ac s as an absolu e alue ope a o . The block cP pe o ms he bounded di e - ence wi h Isa and ixes he slope alue o membe ship unc ion. The ou pu cu en o he MFC ep esen s he complemen a y alue o he membe ship le el o he signal Vin. Ci cui s based on his echnique a e mo e p ecise han o he app oxima ions epo ed in li e a u e, since hey do no depend on a combina ion o wo o h ee unc ions [2-3]. They a e also mo e e icien ega ding a ea, powe consump ion, and ope a ion speed. In addi- ion, p og ammabili y is easily included [4]. B. Mul i-inpu MAX Ci cui The mul i-inpu MAX ci cui which is shown in Fig. 1 pe o ms a double unc ion. On one hand, h ough I e i ixes he maximum membe ship deg ee. On he o he , i implemen s a connec i e MIN be ween he ules an eceden s, using he De Mo gan’s law: Min(Ii) = Max (Ii)= I e - Max(Ii) The ci cui is a modi ica ion o he p oposal in [5] and uses only 3n+1 ansis o s, ye achie ing he same p ecision wi h less a ea and powe consump ion. As shown in Fig. 1, i consis s o a combina ion o Wilson cu en mi o s which sha e a diode-connec ed ansis- o . The Ti ansis o s no only ac as ol age ollowe s bu also conduc he cu en om a low impedance o a high impedance node, a oiding cha ge e o s wi hou addi ional cascode o egula ed s ages [6]. C. Di ide F om a MOS analog ci cui poin o iew, di ision has always been a cos ly ope a ion in e ms o ime and a ea. Consequen ly, many o he epo ed uzzy con- olle s impose he condi ion ha he denomina o in exp ession (1) assumes he alue 1, o ecu o he use o global no maliza ion loops [5, 7] which limi he yo Σihici Σihi ---------------=(1) Cu en -Mode Single on Fuzzy Con olle I. Ba u one, S. Sánchez-Solano, J. L. Hue as Dep . de Elec ónica y Elec omagne ismo, Facul ad de Física, Uni e sidad de Se illa, SPAIN in e ence speed o he con olle and implemen an app oxima ion o exp ession (1). The s a egy ollowed he e is he use o a simple con inuous- ime di ide ci cui which accep s cu en s as inpu s and gi es a ol age as ou pu . Fo his, we ol- low a a iable ans esis ance echnique. This means he use o an elemen which allows a ela ion Vo=In⋅R, wi h a esis ance alue R being con olled by a cu en Id, so ha Vo=In⋅Va/Id. The s uc u e o his ci cui is shown in Fig. 1. The ou ansis o s which o m he a iable ans esis ance elemen ope a e in he ohmic egion. This allows a la ge dynamic ange han ha eached wi h squa e- law s uc u es, and equi es less powe and a ea con- sump ion ( hei geome ies can be minimal). I also pe mi s a high equency ope a ion, since his s uc u e is sel -compensa ed o in insic pa asi ic capaci ances [9]. Finally, i is also mo e obus o ansis o mis- ma ching. III. RESULTS AND CONCLUSIONS The ope a ion speed o he MFC and MIN/MAX blocks is es ic ed by he ime in es ed in pe o ming he bounded di e ence because his in ol es changing ansis o s om being OFF o conduc . Gene ally, hese imes a e less han 300 ns. Rega ding he di ide block, i s dynamics is go e ned by a dominan pole whose magni ude is p opo ional o he bandwid h o he ampli ie and he alue o Id (which co esponds o Σhi). Fo ypical alues, he esponse ime o his block is also some hund ed nanoseconds. Thus, he p oposed con olle can each he ange o MFLIPS. The use o a simpli ied in e ence me hod and he adequa e choice o he ci cui s which implemen he di e en ope a o s eases he ha dwa e ealiza ion o uzzy logic-based con ol sys ems. The main cha ac- e is ics o he p oposed a chi ec u e a e educed a ea cos s, high ope a ion capaci y, simple in e ace wi h con en ional con ol ci cui y, and he possibili y o include digi al p og amming echniques. REFERENCES [1] Chuen Chien Lee, “Fuzzy Logic in Con ol Sys ems: Fuzzy Logic Con olle ” Pa s I and II, IEEE T ansac ions on Sys ems, Man and Cybe ne ics, Vol. 20 N. 2 (1990) pp. 404-432. [2] T. Yamakawa, T. Miki and F. Ueno, “The Design and Fab ica ion o he Cu en Mode Fuzzy Logic Semi- Cus om IC in he S anda d CMOS IC Technology”, P oc. IEEE In . Symp. Mul iple-Valued Logic, May 1985, pp. 76-82 [3] T. Ke ne , C. Hei e and K. Schumache , "Analog CMOS Realiza ion o Fuzzy Logic Membe ship Func ions", IEEE T ans., July 1993, SC- 28, ( 7), pp. 857-861. [4] J. L. Hue as, S. Sánchez-Solano, A. Ba iga and I. Ba u one, “Se ial A chi ec u e Fo Fuzzy Con olle s: Ha dwa e Implemen a ion Using Analog/ Digi al VLSI Techniques”, 2nd. In . Con . on Fuzzy Logic and Neu al Ne wo ks, Iizuka, 1992, pp. 535-538. [5] M. Sasaki, N. Ishikawa, F. Ueno and T. Inoue, “Cu en Mode Analog Fuzzy Ha dwa e wi h Vol age Inpu In e ace and No maliza ion Locked Loop”. IEICE T ans. Fundamen als, Vol. E75-A (6), June 1992, pp. 650-654. [6] I. Ba u one, J. L. Hue as, A. Ba iga and S. Sánchez- Solano, "Cu en -Mode Mul iple-Inpu Maximum Ci - cui ", Elec onics Le e s, Vol. 30 (9), Ap il 1994, pp. 678- 680. [7] T. Yamakawa, “A Fuzzy In e ence Engine in Nonlinea Analog Mode and i s Applica ion o a Fuzzy Logic Con ol”, IEEE T ans. on Neu al Ne wo ks, Vol. 4, No. 3, pp. 496-522, May 1993. [8] M. Ismail, “Fou -T ansis o Con inuous-Time MOS T ansconduc o ”, Elec onics Le e s, Vol. 23, pp. 1099- 1100, Sep . 1987. (2) Ix1 Vbn cP 1 : mx1 Vbp cN Fig. 1.- Schema ic o he p oposed con olle . cN 1o c1h1 h1 o he ules consequen Vx1 V-I I-V MFC Ix2 Vbn cP 1 : mx1 Vbp cN Vx2 V-I MFC I e MAX DIVIDER :1 :c1