51 control umrzj drive voltage ge_n§r_a1_'o_r

US006246197B1

(12) United States Patent Kurishige et al.

(10) Patent N0.: (45) Date of Patent:

US 6,246,197 B1 *JIIII. 12, 2001

(54) ELECTRIC POWER STEERING (56) References Cited CONTROLLER U.S. PATENT DOCUMENTS

(75) Inventors: Masahiko Kurishige; Noriyuki Inoue; 4,943,758 * 7/1990 Tsurumiya ......................... .. 318/504 Takayuki Kifuku; Munenori 5,553,684 * 9/1996 Wada et a1. .... .. 318/432 Yamamoto; Shunichi Wada, all of 5,623,409 * 4/1997 Miller . . . . . . . . . . . . . . . . . .. 180/443

Tokyo (JP) 5,652,487 * 7/1997 Nishino et a1. .... .. 318/434 5,703,456 * 12/1997 COX . . . . . . . . . . . . . . . . . . . . .. 318/138

(73) AssigneeZ Mitsubishi Denki Kabushiki Kaisha, 5,780,980 * 7/1998 Naito . . . . . . . . . . . . . . . . . . .. 318/139

Tokyo (JP) 5,786,679 * 7/1998 Nishino et a1. .... .. 318/439 6,131,059 * 10/2000 Kaji et a1. ............................ .. 701/41

(*) Notice: This patent issued on a continued pros- FOREIGN PATENT DOCUMENTS

ecution application ?led under 37 CFR 718 174 6/1996 (EP) 1.53(d), and is subject to the tWenty year ' patent term provisions of 35 U.S.C. 8475404 7/1996 (JP) '

l54(a)(2). * cited by examiner

- - - - Primary Examiner—David S. Martin Sub]ect to any disclaimer, the term of this _ _ _ patent is extended or adjusted under 35 S14) Agkor‘geg’ Agg?ticor F W m—sughrue’ Mlon’ Zmn’ U.S.C. 154(0) by 0 days. “P6 eas>

(57) ABSTRACT 21 A l. N .: 09 044 349

( ) pp 0 / ’ To estimate the rotation speed of the motor for assisting a (22) Filed: Mar. 19, 1998 steering torque regardless of the running state of a vehicle

_ _ _ _ _ With accuracy, an application voltage estimation value

(30) Forelgn Apphcatlon Pnonty Data obtained by subtracting a correction voltage obtained based Sep. 5, 1997 (JP) ................................................. .. 9-240611 On a detection Current Value detected by Current detection

7 means from the inter-terminal voltage measurement value of (51) Int. Cl. ...................................................... .. H02P 7/00 the motor is Output and the rotation Speed of the motor is (52) [15- Cl- ~~~~~~~~~~~~~~~~~~~~~~~~~~ -- 318/432; 318/434; 701/41; estimated based on this application voltage estimation value

180/443 and the detection current value. (58) Field of Search ................................... .. 318/432, 434;

180/443—446, 400; 701/41, 43 13 Claims, 24 Drawing Sheets

9 r/ VOLTAGE DETECTION 5 ‘sns ISHS MEANS _ _ _ _ ‘L’ _

V8-85‘! r———1———-— '1 \-'\ l OLTAGE VOLTAGE '

TLORRECTING IUEJATSURING k‘5_ " 5b” UNlT ‘ a L _ _ _ _ _ _Vl—_$DS_ _ _ _ n: 1? Isns A

i “<51 CONTROL umrzj DRIVE VOLTAGE GE_N§R_A1_'O_R‘;? ), l- _ _ _ _ — T '- _ _ T _ _ w _ _

VET | ‘ - SPEED I | ROTATION | CURRENT

SPEED - ll"coNTRo'- ‘ | i : DETECTION OUTPUT ESTIMATION I U" ‘T | I I MEANS TORQUE SPEED I 14’ l I ‘ Ia~ DRIVE

l 7 T5,, } a ID 1c I I 2a 2b 2c I Vt TORQUE 8

\ iii ,./ |:—- // / {{';"'“ _'"_“l // STEERING 1 TORQUE I + CURRENT DRIVE + I MOTOR STEERlNG TORQUE CONTROL CONTROL COIL SHAFT NIT

KDEIZJ'ECTSION } UNIT UNIT TC‘RCU/S: : x H ; U M AN I I '

1 “'9 Vt_ind Vdrv I L X132“; _3lb_l STEERING 1- — - — - - — - J '- — — — — — — — — - — — — ——-‘ MOTOR \\ REACTION

TORQUE lref 3a ‘ TORQUE

U.S. Patent Jun. 12, 2001 Sheet 2 0f 24 US 6,246,197 B1

FIG.2

( START ) V

READING Vt_sns AND Isns

I OBTAINING Vcomp FROM Isns WITH REFERENCE TO TABLE @5102

CALCULATING Va_est=Vt_sns—Vcomp @5103

AND STORING IN MEMORY

T\— 5101

READING Rac AND Kec ‘@5104 F

CALCULATING west=(Va_est-—Isns x Rac)/Kec AND STORING IN MEMORY N 5105

CALCULATING Ive! FROM west AND STORING IN MEMORY W\.,SIO6

1

READING Tsns /\~SIO7 I

CALCULATING Itrq FROM Tsns AND STORING IN MEMORY “5108

I ALCULATING Inef=lvei+ltrq 5109 NO STORING IN MEMORY A’

I

( RETURN >

C A


FIGA

@ READING VLsns AND Isns /\/ SZOI

OBTAINING Vcornp FROM Isns WITH REFERENCE TO TABLE “5202

I CALCULATING Va_est=Vt_sns—VcOmp AND STORING IN MEMORY “k520i;

I READING Rac AND Kec ’\, 5204

I CALCULATING west = (Va_est —— Isns x Rac)/ Kec AND STORING IN MEMORY ’\/ 5205

I CALCULATING IveJ. FROM west AND STORING IN MEMORY /\S206

' I

CALCULATING dwest BY DIFFERENTI ATING west AND STORING IN MEMORY/\ISZO7

CALCULATING Iacc FROM dwest AND STORING IN MEMORY "\JSZOB

READING Tsns @5209

CALCULATING Itrq FROM Tsns AND STORING MEMORY @5210

I

CALCULATING Iref : lve1+ Iacc+ltrq AND STORING MEMORY a’ $211

I

I RETURN I


FIG. 5

CORRECTION VOLTAGE? VcomIV) UPPER "

LIMIT Vmax GRADIENT Kcomp OF

PROPORTIONAL PORTION

COIL CURRENT MEASUREMENT VALUE Isns(A)

FIG. 6

@ READING Vmax AND Kc0mp,\’S3O1

I READING Isns 5302

T CALCULATING Vcomp = Isnsx Kcomp @5303

5306

I 530 STORING

* YES Vcomp=Vmax-sign(Vc0mp) STORING Vcomp IN MEMORY IN MEMORY

@


FIG.7

CORRECTION VOLTAGE Vcomp( V)

UPPER — — — —

LIMIT Vmax

GRADIENT K2comp OF SECOND PROPORTIONAL PORTION

GRADIENT KIcom OF FIRST PROPORTIONAL P RTION

UPPER LIMIT CURRENT Imax


FIG. 9

CORRECTION VOLTAGE Vcomp(V)

UPPER LIMIT Vmax

COIL CURRENT MEASUREMENT VALUE lsns (A)

FIG. 10

( START )

READING Vmax I

“5501 READING Isns m 5502

YES f/ssoa ‘ f/ 5505 STORING STORING Vcomp : Vmax Vcomp : —Vmax IN MEMORY IN MEMORY

( END )

U.S. Patent Jun. 12, 2001

FIGII

CORRECTION VOLTAGE Vcomp (V)

Sheet 9 0f 24 US 6,246,197 B1

UPPER LIMlT/_\'/ Vmax

FIG. 12

@ READING Vmax

I "\Js 601

READING VtLsnS AND Vt2_sns

Nseos STORING STORING Vcomp= Vmax Vcomp= —Vmax IN MEMORY 1N MEMORY

END

U.S. Patent Jun. 12,2001 Sheet 11 0124

FIG. 14

( START )

US 6,246,197 B1

READING V2com FROM ROM p’\/S~70'l

READING Vt_ind AND lsns ‘ m5702

OBTAINING Vcomp FROM lsns WITH REFERENCE TO TABLE -’\,5703

\

CALCULATING Va _est= Vt._ind -— Vcomp — V2comp ,

AND STORING 1N MEMORY 5704

(E


FIG. 16

@ READING V2comp FROM ROM M5801

I READING Vt_snS, Vt_ind AND Isns /\/ S802

OBTAINING Vcomp FROM Isns WITH REFERENCE TO TABLE /—\_/ S803

I

CALCULATING Va_estI=Vt_sns—VcOmp AND STORING IN MEMORY ’\ 5801,

I CALCULATING Va_est2 = Vt_ind -— Vcomp — V2comp AND STORING MEMORY /\ $805

I PASSING Isns THROUGH LOW PASS FILTER AND OBTAINING Isns_LPF /\ 5806

OBTAINING Kw FROM Isns_LPF WITH REFERENCE TO TABLE - ’\ 5807

CALCULATING Va_eSt= Kw-Va..est1+(1— Kw) ' Va_est2 ANO STORING IN MEMORY \5808

END


FIG.18 @

READING Vt_sns AND lsns 590‘

OBTAINING Vcom AND VCOmp_d FROM 1535 WITH N 3902

REFERENCEw TO TABLE CALCULATING Va_est= VLsns-V comp AND STORING IT IN MEMORY ’\ 5903

I

CALCULATING Va_esI_d :VI-sns-Vcomp_d 5904 AND STORING IT IN MEMORY P/

I

READING Rac AND Kecrv 5905

CALCULATING west = (Va_est — Isns x Rad/KecN

AND STORING {IT IN MEMORY

CALCULATING wesLd =(Va_est_d -Isns x Rac)/Kec/\’ 5907 AND STORING I'T IN MgMORv CALCULATING lvel FROM west AND STORING IT IN MEMORY “5908

CALCULATING dwesi BY DIFFERENTIATING S909 wesLd AND STORING IT IN MEMORY E’

T CALCULATING IacC FROM dw st AND STORING IT IN MEMORI? N 5910

I

READING Tsns NSQII

I CALCULATING I'trq FROM Tsns M5912 AND STORING IT IN MEMORY

CALCULATING lref=lvel+lacc+ltrq~5913 AND STORING IT IN MEMORY

( RETURN )


F1620

@ READING V2 comp FROM ROM M51001

1 READING Vt__ind AND lref N 51002

. 1 OBTAINING Vcomp FROM [ref 51003 WITH REFERENCE TO TABLE N

CALCULATING Va_est=Vt._ind-Vcomp—V2compN51004 AND STQRING IT IN MEMORY

END

U.S. Patent

FIG.2I

Jun. 12, 2001

( START ) I

Sheet 18 0f 24 US 6,246,197 B1

INCREME BY ONE

NTING tdest

I

READING Vt__sns, Vdest Isns AND tfin

WSITOZ

I

OBTAINING Vcomp FROM Isns WITH REFERENCE TO TABLE A’ S1103

Vt_sns>Vdest I

NO

51104

51107 //

RESETTING TIMER (tdest=0)

tdest < tfin

S1105 51108

No OBTAINING CORRECTION COEFFI CIENT KdestFROM tdest WITH REFERENCE TO TABLE

Vcomp: VcompX Kdest

‘d \

S1109

STORING Vcomp 51106 IN MEMORY /\/

END


FIG. 22

( START )

INCREMENTING tdest BY ONE

READING vt_srjs ldes‘w $1202 lsns AND Um

OBTAINING Vcomp FROM lsns WITH REFERENCE TO TABLE x5903

S1204 - 51207

/ NO RESETTING TIMER

(tdest=0)

S1205

S1208

/ NO OBTAINTNG CORRECTION COEFFI

CIENT Kdest FROM tdest WITH REFERENCE TO TABLE

tdest < t fin

Vcomp= Vcomp X Kdest

\ ‘ S1209

STORING Vcomp M51206 IN MEMORY

51 control umrzj drive voltage ge_n§r_a1_'o_r

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