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Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 November 1990 https://ntrs.nasa.gov/search.jsp?R=19930022252 2020-03-17T19:26:49+00:00Z

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Page 1: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Masaki Togai Togai InfraLogic, Inc

Fuzzy Logic Workshop 14 November 1990

https://ntrs.nasa.gov/search.jsp?R=19930022252 2020-03-17T19:26:49+00:00Z

Page 2: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

THE JAPAN TIMES SATURDAY, SEPTEMBER 1,lW 13

CARTOONS

Page 3: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

b

a l

I Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

Fuzzy Logic -

Is Well Suited For Handling

Non-Linear, Time-Varying, and/or Ill-Defined Problems I?

vinw i A

L

Page 4: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Canon

Daldan Fujl Electrlc

Hltachl

ldec lzuml k: lshlda Instruments

Leon Auto Machinery Nlppon Steel Maruman Mycom Melden-sha

Mlnolta Mltsublshl Chemlcal Mltsublshl Electrlc

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHlP

Japanese Companies Employing Fuzzy

SLR camera focuslng Stepper control Clean room temp &

humldlty control Gas coollng plant Chemlcal mlxer Waste burnlng plant Sendal Subway control Elevator control GaAs crystal growth Autornatlc measurlng Food processing Iron mlll control Golf club selection Robotlc controllers Dredglng control Machine control Camera focuslng Cement klln control Elevator control Plasma Etchlng

Mltsublshl Heavy Matsushlta (Panasonlc) Nlssan Motor Company

Nuclear Power Corp Omron

Rlcoh *

Sanyo Selko Subaru Toshlba

Yamalchl Securltles Yokogawa Electrlc

Alr-condltlonlng systems Temperature controllers Automatic transmlsslon ABS braklng system Nuclear power plant control Factory controllers Robotlc controllers Camera stablllzers Camera focuslng Volce Recognltlon Camera Iris control Deslgn expert system Autornatlc transmlsslon Elevator control Product deslgn expert system Stock tradlng Dlgltal measurement systems

P - Productlon D - Development

Page 5: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

SUITABL .E APPLICATION AREA OF FUZZY THEORY

TOGA1 INFRALOGIC, INC.

Problems of .conventional approach

~ p p l l c a t i o n s

I

\

Classi f icat ion problem

*Action to be taken is not clear

*Cannot discribe all solutions for possible patterns

f speedlhardware l im i t a t i ons .

\ Auto- i r is tauto- focus

Hand-written character recognition

Automatic transmission

.

Man-Machine Interface Problem

*Difficult to express control objecitides numerially

*Evaluate the control result by human feeling

L

Sendai subway

Suspension control

Crane control

Automatic transmission

SUITABLE PROBLEMS Time-varying dynamicslnon-linear problem

*Plant dynamics varys in time

*Plant i s non-linear + overshoot o s c i l l a t i o ~

Temperture control of AIC, plant, etc.

Position control of a hard-disk head

Auto-cruise

Page 6: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

CHARACTERISTICS OF FUZZY CONTROL

TOP VIEW

VARIABLES ____) I

OBJ 2

OBJ N

TOGAI INFRALOGIC, INC. KYOTO- 1

Page 7: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

CHARACTERISTICS OF FUZZY CONTROL

BRODUCTIOI R'JLES (IF-THEN)

- SIMPLE KNOWLEDGE REPWSENTATION - MIXED PREMISE EVALUATION - EXCEPTION HANDLING

QUALITATIVE EXPRESSIONS

b-bIMPROVEMENT ON . QU..ITY & ROBUSTNESS

TOGA1 INFRALOGIC,' INC. KYOTO- 1

Page 8: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

FUZZY CLOSED-LOOP CONTROLLER

FUZZY b b SV CONTROLLER PROCESS

- MV PV

%

TOGA1 INFRALOGIC ,' INC . ' KYOTO-3

Page 9: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its
Page 10: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Mitsubishi Heavy Air Conditioner

April 1988 First, Design

Simulation by Summer

Production October 1989

Page 11: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Mitsubishi Heavy Air Conditioner8

Room Heating a,nd Cooling Times Reduced by 5X

Temperature Stability Increased by 2X

0 Overall Power Savings of 24 /O

Reduced the Required Number of Sensors

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

8

L - -- A

Page 12: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

FUZZY INVERTER AIR CONDITIONER SYSTEM .

TEMP. ERROR FUZZY TEMP. CHANGE INFERENCE

1

/

FUZZY' RULES 50 RULES (HEATINQ&AIC) -

'MAX-PRODUCT INFERENCING I M~~~~~~~ I WN SPEED)

DEFUZZIFICATION: 1 I CENTROID METHOD

Page 13: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTlFlCfAC INTELLIGENCE ON A CHIP

Mitsubishi Heavy Air Conditioner

Page 14: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

R

k

Mitsubishi Air Conditioner

3 0 *c

a*--.--- --- --- ---------*----

10

*---------

"

10 20. 30 ' 40 . --. .

13 ray 53

Page 15: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

N I

8 g s s

r

- - - - - - - - - J ~ ~ ~ ~ ~ I I I I I I I L ~ ~ I ~ ~ ~ I ~ ~ I ~ ~ ~ ~ ~ ~ ~ ~ ~ I ~ ~ ~ ~ ~ ~ ~ ~ , ~ ~ ~ , ~ ( ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ J ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ , ~ , ~ , ~ ~ , ~ ~ , J

0 t 10 20 30 40 50 60 70 80 90 100 .

3 m 3)

- --

Page 16: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai I nfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

Stanford June '89

FUZZY2 (#Z!Eh j,& Z 3-1 UZZYl (ZZ*&Pfi) .

PID ($i!%)

0-

i

. .

Page 17: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its
Page 18: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

PREDICTIVE FUZZY CONTROL

, I f

Fuzzy CONTRO? CONTROL RULES PURPOSE 1

OBJECTIVE CONTROL ACTUAL DIFFERENCES COMMAND STATE

b FUZZY &PROCESS * b

STATE 6 INFERENCE

OBJECTIVES PREDICTION

4

4 -

SENDAI SUBWAY CONTROLLER

TOGA1 INFRALOGIC, INC . KYOTO-5

Page 19: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System

Xd Safety

- v(t)-- , q Running Time . TASC - N ~ T : TASC c o n t r o l corrrna , ~ o n t S o 1 to be selected

N ( t ) ' * Comfort -, Npc: CSC c o n t r o l corrrna

t o be se.lected

- x ( t ) . .-. ?Energy

Xt Stop Gap

+ Saving + - --j

V t

Structure of Fuzzy TO algorithm

T r a c e a b i l i t y -- - . +

+

Choice o f the T o t a l Cont ro l Notch

+PN

+ BN

Page 20: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System ,

First Proposed to the Government 1978

Granted Permission to Operate After: 8 3,000 Empty Subway Runs

300,000 Simulations

Began Operation in 1986

Hitachi Granted Contracts for Tokyo Subway 1991

Page 21: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System

Performance Improvements

Improvement in Stop Gap by 3X

Reduction in Power Settings by 2X

Overall Reduction in Power by 10%

Page 22: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

r\///I Togai InfraLogic, Inc. I I ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System

( : Performance index Limited Speed

Target Speed

Automatic Train

Position

CSC Position TASC Position Marker Marker

-.Outline of automatic train operation . .

Page 23: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System ,

W ATC Wayside System ATS System (Automatic (Automatic Train Control) T r a i n supervision)

I I 1 rain detection I I Supervisory

and Signaling Command

. . Typical configuration of AT0

Page 24: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai Inf'r-oLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System

T a b l e 1 Sjmbols t : time (sec) x ( t ) : locat ion o f t r a i n (m) v ( t ) : v e l o c i t y o f t r a i n (km/h) N ( t ) : c o n t r o l command notch X ( t ) : t a r g e t pos i t i on of next s ta t ion (m) V t : ta rge t speed (km/h) T t : predicted running time (sec) ul

h)

Xd : forward locat ion where the maximum speed l i m i t i s lower ( m ) t s : time t o reach Xd p o i n t (sec) Xk : ending locat ion o f coast'ng (m) X,(V) : beginning po in t o f TASC zone (m)

I

tZ = (Xz(v ) -x ( t ) ) / v ( t ) : time t o TASC zone (sec) Z tc : elapsed t i m e from last notch change (sec)

Nc : degree of l a s t changed notch

Np : con.tro7 command notch t o be selected 'Jp(Np) : pred ic ted speed when Np notch i s selected (km/h) v e : v e l o c i t y allowance range (km/h) X p ( N p ) : pred i c ted stop p o s i t i o n i f Np notch i s selected (m) Xe : allowance of stop gap (m)

Page 25: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

The Sendai Subway System

Page 26: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Fig. 1 Outline of automatic train operation by PID control Fig. 2 Outline of automatic train operation by fuzzy control

Theory of Fuzz:ness 8 Fuzzy Cont of The theory of fuzziness was first proposcd in 1965 by professor LA . Zade'~ of the University of California at Berkeley. The theory of f i zziness deals with i~ set with ambiguous boundary instead of a1 ordinary set. In the conventional Boolean set com~rising "0" and "*," t.,e b~undary of an individual set can be cf:a*ly 'is inguished, but the fuzzy set i s characterized by the '1 t that t'ie boundary between the inside and outside of th. set i s not obvious. The fuzzy control is based on the fuzzy set t' eory which was developed for c'etermining the quantitl of subjective

' fuzziness of human being and for mL.'ng ob: -tive evdue- tion of the * 12-iness possible, a ~ d thereby eD'n.:nating fuzzy portions as m ch'as poss:ble. In the conventio ial automatic ' opcrdtion s)s*en,

train operation i s performed ' y a c>n.rol based or I 3 Control (Pro?onional Integra. d and Differential Contro') so that target speed pattern ,.r termined for each operat- ing section can be follow . I I this conventional au-o- matic train operation, accur re operation can be achieved in a manner of following the predetermined speed pattern. However, in actual practice. there are many kinds of

changes of running condi ions such as gradient etc. of

track and the braking force of rolling stock. Therefore, to follow the target speed, i t i s necessary to send ntrrl commands frequently for acceleration and brake app1i.d- tion. As a result, smooth operation is apt to become dif- ficult, and riding comfort i s likely to be degraded. More. over, an accuracy of train stopping at predetermined loca- tions of stations cannot be determined through the logic of the control system. Accordingly dispersion should be checked by computer simulation or tests using real cars. This kind of problem occurs because 'he train o~eration characteristics as a controlle 1 system are not well adapted to i t s coitrol system. The characteristics of running train vary complicatedly and non-linearly in response to changes in the evternal situation. In the conventional control method, complicated controlled systems, wen dealt with approximating then to Sim~lt linear models, and only the follow-up to predete mined s,~eed pattern was taken into account in the evaluatior related to control. That is, the conventional control was unable to properly respond t~ changes in the situation. : , th? other h~nd, in the fuzzy control, the results of ~enain runnii- ~perztions being considewd are predicted ii advance as the same as act~al decisions made by a

Fig. 3 Comparison of the results between furry control and PID control (stop accuracy and number -f times control command changes)

Page 27: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

The Sendai Subway System

Stop-Gap and Power Settings

Page 28: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

MI.# --

I Nissan Close To Introducing Fuzzy Logic Transmission Controller by ANDREA SAXER

S mn-in the next year or so-Niuan will start sell- ing cars programmed

with a new, extra smart tram- mission control, popular ly known u hzzy logic Specula-

8 tion is that inference-based wn- trol logic will debut on N i n ' ~ 300 W. the company's premier perfonnana car, and perhaps on its lnfiniti Q45 luxury sedan.

Indust ry Analyst Roger Sleciak, San Jose, CA. reported Subam and Mazda ue acriously pursuing the m e mar t control technique. He predicted r two- to three-year time frame lor thh to happen, at most.

Like N i Subm wil l apply Lay logic to trans&ion wn- trol. M d a is testing i t for appli- cation in collision midance sys- tem. I n Mazda's case, Steciak expected r long lead time. as much u ten years. since legal approvals for its syltem will re- quire extensive testing.

Hiroshi Takahashi, research R O I I O F ~ M R C E I engineer at Nirran's Central En- WHAT A DIFFERENCE: More shifting, less cantoct. Honda studed shin schedulirig and found mat gears were s h h d less h e * gineering Lnboratories. Yokosu- transmission was controlled by buy logic rather than a Wadi-

La. Japan, mid Honda m d lsuzu program. The ampartson chart comes horn a psper (*go50191 are working on f u q logi: br CONCEPTUALLY SPEAKING: The Nissan Arc-)( concept car has a senled by Honda Research and Developmen1 Enplneen Sakai. automolive electronic controls control schema that could lnmrporale h r q bgic. according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its Hiroshi Takahashl, a research englneer at Nissan's Central Engineer- tomotlve Eng~neer~ng Soclel~es In Turin. Ilaty. In May Call S h q

Plcnsc. scc Fuz:y L q c , p. I2 Ing Laboralortes. Yokosuka. Japan of Automotive Eng~neers. Warrendale. PA. 4 12 775 4 8 : 1.1:. a C - 7 .

H n i l ~ c Committep QKs Toyota Jig ;n hfin"~ W C Fllndinn V P r . . - . c c m - +

Page 29: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its
Page 30: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

I

KNOLEDGE BASE (IF* -THEN* 0)

1. ',- ..

SENSOR -LC INPUT REASONING OUTPUT

BLOCK BLOCK AT

BLOCK . . 1

4 J

Page 31: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Automatic Transmission . I

I

' 0 50 100 150 Velocity ( h / h )

I Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

UI w

view1 'I

- - - - -

Page 32: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

Togai InfraLogic, Inc. ARTIFICIAL INTELLIGENCE ON A CHIP

Automatic Tr.ansmission

180 Time

Page 33: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

I

~ I C , . ~ I ) A I . , J ~ I I . I . ~ , , 17H9 A I : T O M O T I v E ~ L E c T R ~ ~ ~ ~ N E u ' s ' 7 . -...- - . . . . . - - , , . - - - ..- I .... .. .

a

Nissan Patents 'Fuzzy ~og ic ' ABS, Gearbox By ANGELA G. KlSG

T ROY, Mich. - Nissan Motor Co. Ltd. has received U.S. patents on an anti-lock brake system

FUZZY LOGIC CONTROLLED ABS and a transmission that incorporate "fuzzy logic" computer programming,

Designcd to automate human rea: sonins, fuzzy logic programming offers various possible solutions, using grad- ed or qualified statements, to a prob- i cm rather than the precise yesor-no solution of strict logic widely used in lhc electronics industry, according to Lofti A. Zadeh, who first developed the concept of fuzzy reasoning in the mid- 1 96CS.

Mr. Zadeh i s currently a Professor of Computer Science in the Electrical Engineering and Computer Science de- par:ment at tne University of Califor- ma at Berkeley.

A h'issan spokesmah said engineers are still developing the brake and transmissions systems, and no intre duction dates have been set. Nissan has developed a fuzzy logic program and is now looking to see if it can be applied to its patented transmission W1- and brake systenl designs* he AhTHROPOMORPHlC: Nissan's fuzzy logic prognrn is dcripned to apply plained. F u y logic p.ogramming, ac- cordng to the company, would en- human reasoning characteristics to the co .trol module of its patented ABS hance brake and transmission system design. performance with improved control flexibility. cision on whether to shift gears. bile engine control, said Mr. Zadeh.

h'issan is developing an automatic U'here conventional ABS incorporate Japan in articular has sholvn a tansmission in u9hich fuzzy logic com- sensors that detect vehicle and wheel great deal o /' interest in fuzzy logic. puter programming is used to electron- speed, the Nissan system's (patent Research is being c tducted in Japan icaliy sMt gears in a manner similar number 4,842.342) control unit mea- in the application crf this system in to a drive: who weighs ddferenl fac- sures these variables in addition to de- such areas as \*rh:<e control at the tors to rnznually shift gears. rivatives of wheel speed with respect Tokyo Institute of Technology's Sugeno

to time and derivatives of vehicle Laboratoq, and robot control at Hosei WITH A CONVENTION.4L automatic speed with respect to time. As in the University's -Hirota Laborator?.. Zansmissioc, elec3onic sensors detect transmission, certain signals in the In March,;3apanVs Ministry o! Inter- veh.~cie speed and throttle opening, and brake system are assigned weighted national Tfa'de and Industry e s u b

are su t ed based on the prede- values that determine the frequency of lished the Laboratory for Internationhl termined value of these factors. Ac- ABS brake actuation. Fuzzy Engineering Research (LIFE;. cording to Kissan, this type of system In a paper entitled "AiaWng Comput- a group that consists of 46. member is incapable of always providing satis- e n Think Like People," hit. Zadeh ex- Japanese firms, including Nusan. factov control performance to a driv- plained that fuzzy logic allows comput- A fuzzy system developed by Hi&- er because it provides a t most only e n to handle such imprecise human chi, also a member of the new LIFE about three ckf!erent shift patterns. concepts as "small," "big," "young" organization, is alread used to controi

la But the Nissan fuzzy control trans- and "old" by describing them in rang- subwar trains in San i, Japan. mission, (paten1 number 4,841,815), is es of numbers instead of exact terms. Fuji Heavy Industries Ltd., the m):- more flexible and provides a dnver er of Subaru cars. is developing i:.. with more control performance be- DEVELOP~XENT OF FUZZY logic in advanced form of electronic continu cause it is operated by sensors that the early 1950s by Ebrahim Mamdani, .ously variable transmission, called :hc. assign values to numerous variables, a control engineer at Queen Mary Col- ECL'T-11, that also uses f ~ ! : contro:c including vehicle speed, throttle open- lege in London, an2 Seto ksilian, Alr. The ECVT-I1 is not in production no:: ing, acceieration and the rate of Mamdani's student at that time, has and is not evpected to appear in a: change of the throttle opening. Each led to growing interest in the use of automobile before model Y e r 1991. 5 c -

~ a l u e is given a weight, and the this theory in such applications as in- cording to a spokesman at Subam weigh& are calculated to make the de- dustnal process control and autome America, C h e q W. N.J .3

,._ __ . .__. - - . __ _ . . . -.-. ...- --. . .*.-- 61

a

Page 34: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

FUZZY LOGIC-BASED COMMAND SYSTEM FOR ABS

SUPPLEMENTARY COMMAND HYDRAULIC PRESSURE

WHEEL VEHICLE VELOCITY

REGULATOR

TOGA1 INFRALOGIC, INC . KYOTO- 6

Page 35: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

FUZZY FEED-FORWARD CONTROLLER

,FUZZY .CONTROLLER7 ,PROCESSr b SV CONTROLLER EV MV PV -

A

Page 36: Masaki Togai Togai InfraLogic, Inc Fuzzy Logic Workshop 14 ... · according to Hasegawa. Sakagucht and lwaki al the lnletnal~wlal Federaton of Au as well. Engine control, with its

FUZZY 4

INFERENCE

- P I D CONTROLLER PROCESS b

EV MV PV

TOGA1 INFRALOGIC; INC. . KYOTO-3