gait generation system of legged mobile robot

US006301524B1

United States Patent (12) (10) Patent N0.: US 6,301,524 B1 Takenaka (45) Date of Patent: Oct. 9, 2001

(54) GAIT GENERATION SYSTEM OF LEGGED 5-318339 12/1993 (JP) . MOBILE ROBOT 5-324115 12/1993 (JP).

(75) Inventor: Toru Takenaka, Saitama (JP) OTHER PUBLICATIONS Stitt, et al., Distal learning applied to biped robots, May

(73) Assignee: Honda Giken Kogyo Kabushiki 1994, pp, 137_142_* Kaisha, TOkYO (JP) Communication—Search Report of Jan. 27, 2000.

English translation of Abstract of JP 5—285868. ( * ) Notice? Subject to any disclaimer, the term of this English translation of Abstract of JP 5—62363.

Pawnt is extended or adjusted under 35 English translation of Abstract of JP 5—305585. U-S~C~ 154(k)) by 0 days- English translation of Abstract of JP 5—318339.

English translation of Abstract of JP 5—324115.

(21) Appl. No.. 09/095,438 * Cited by examiner

(22) Flled: Jun' 10’ 1998 Primary Examiner—Paul P. Gordon (30) Foreign Application Priority Data Assistant Examiner—Zoila Cabrera

(74) Attorney, Agent, or Firm—Lyon & Lyon LLP Jul. 25, 1996 (JP) ................................................. .. 8-214261

7 (57) ABSTRACT (51) Int. Cl. .................................................... .. G06F 19/00

(52) US. Cl. ..................................... .. 700/245; 318/568.12 In a gait generation system for a legged mobile robot, in (58) Field of Search ................................... .. 700/245, 250; particular a legged mobile robot having a body and 4

31856812 plurality of legs links each connected to the body through a joint, it is con?gured such that gaits comprising motion

(56) References Cited parameters and ?oor reaction force parameters are varied freely on a real-time basis during Walking. In order to effect

U'S' PATENT DOCUMENTS this, various standard gaits have been prepared on an off-line

5,325,031 * 6/1994 Tilden ........................... .. 318/568.11 Computer and an approXimated Value Such as a Weighted 5,357,433 * 10/1994 Takenaka et a1, _______ __ 701/23 average thereof is calculated in response to a demand for 5,402,050 * 3/1995 OZaWa .......................... .. 318/56812 gait, and gaits are generated. Moreover, the gaits are cor 5,428,563 Takenaka ........................... .. reeted using an inverted pendulum model such that positions 574327417 7/1995 Takenaka ct a1~ - 318/568-12 and the velocities are continuous at the boundary of the 5’594’644 1/1997 Hasegawa et a1‘ """" " 701/93 gaits. With the arrangement, it becomes possible to generate 5’642’467 * 6/1997 Stover et a1‘ 700/250 gaits having the ?oor reaction force freely on a real-time 5,807,011 * 9/1998 Hong et a1. .......................... .. 403/62 . . . .

5,808,433 * 9/1998 Tagami et a1. ................ .. 318/568.12 basls to effect, a Smde or “1mg angle as deslred' It 91,50 578427533 4 12/1998 Takeuchi _ _ _ _ _ _ _ _ _ _ _ __ 180/81 becomes possible to make the displacements and velocities

5,872,893 * 2/1999 Takenaka et a1. ................. .. 700/245 of Various Portions of the robot Continuous at the boundary of the gaits. In addition, it becomes possible to control the

FOREIGN PATENT DOCUMENTS

5-62363 9/1993 (JP). 5-285868 11/1993 (JP). 5-305585 11/1993 (JP).

SETS‘ OF STANDARD RE BY GAITS (PREPA D GENERATOR

legged mobile robot based on the gaits thus generated on a real-time basis.

31 Claims, 38 Drawing Sheets

MIXED GAIT INSTANTANEUUS VALUE

OFFLINE COMPUTER) ,,,,, ,_

JD. NUMBERS OF

I STANDARD GAITS BODY TiMEsERrEs To BE MJXED AND DATA (X, y) g0) WEIGHTS — _

MOTION nORIZONTAL BODY I BODY POSITION TRAIECTORIES PARAMEI‘ERS GENERATOR 1, b a b '’ (FOOT LIFI'ING X ‘y ' X '

POSITION, FOOT a Y"v 5 1" LANDING '

POSITION SINGLE'LEG FEET SUPPORTING RJEN DESIRED PHASE PERIOD, FosmoN/O ION‘

E ETC) FEET IATXON INVERSE I; MANDw TRAJECI‘ORY I'I‘RAJECI‘ORIES I DOUBLE'LEG ANGLES, FOR L’MT GAIT GENERATOR 4' cuMPLIANCE *KWEMAUCS '

Rf, yf, zf. 5 X“ CALCULATOR _> mm H yfl H Lf coNrRoLLER a, 1), etc.

BODY

BODY HEIGHT I HEIGHT I . ._ DETERNHNATOR :fA'Ecu‘l' I

ZMPPARAME‘I'ERS 1M? {(1) R .>

GENERATO ZMP 'I‘RAJECTORY

TIME!

GAIT SWITCHING TIIVEE

U.S. Patent 0a. 9, 2001 Sheet 1 0f38 US 6,301,524 B1

[_~'~__"_~""__~~___~_“—1 I INCLINATION SENSOR I I I I b

I I I |

SIGNAL

I CONTROL

UNIT

Z

I I I I I I I I I

I I I I

I I I I I I I I

L 6-AXIS FORCE AND TORQUE SENSOR SIGNAL

U.S. Patent Oct. 9, 2001 Sheet 2 0f38 US 6,301,524 B1

FIG.2

2S6 IST 8 0 7 0\ — JOYSTICK ~62

CALCULATOR ' _ A/D _ KINCLINATION N60

82 SENSOR

2ND , 6-AXIS FORCE ~4 4 _ = AND TORQUE

CALCULATOR / 76 SENSOR 7 2 7f ROTARY

COUNTER _ ENCODER

[534 MOTOR ‘ ROM {86

74 D/A SERVO-‘AMPLIFIER

RAM "

U.S. Patent 0a. 9, 2001 Sheet 4 0f 38

FIG. 4

START s10

/ STORE STANDARD GAITS PREPARED BY OFFLINE COMPUTER IN MEMORY

AND VELOCITIES IN STANDARD GAITS CALCULATE AND STORE FINAL BODY POSITIONS

S12 /

/S14

WAIT FOR TIMER INTERRUPT (AT EVERY CONTROL CYCLE) /

yes

AT GAIT SWITCHING

CONDUCT

rS22

US 6,301,524 B1

S18

S24 / READ DEMANDED VALUES FOR DIRECTLY DETERMINED PARAMETERS IN NEW CURRENT GAIT

CONDUCT PROCEDURES FOR GAIT MIXING (SELECT STANDARD GAITS TO BE MIXED AND DETERMINE WEIGHTS, AND GENERATE MIXED GAIT PARAMETERS)

/

f SUBSTITUTE MIXED GAIT PARAMETERS (TABULATED DATA) FOR DESIRED GAIT PARAMETERS (TABULATED DATA)

S26

S28

PROCEDURES FOR CALCULATING N STANTANEOUS VALUES OF DESIRED GAIT

S30 /

t=t+At / S32

END


FIG. 5 STANDARD GAIT NO. 0

INITIAL FREE FINAL FREE LEG POSITION LEG POSITION AND (LEFT) AND ORIENTATION HY ORIENTATION

A

' > X (TO)

SUPPORTING LEG POSITION AND ORIENTATION

FIG. 6

UPWARD FEET TRAJECTORY

(T0) FREE LEG FOOT SUPPORTING

LEG FOOT


FIG. 7

SUPPORTING LEG HEEL POSITION t4 Xzrnp

1 2 CO I I t3

0v 1 , INITIAL FREE ‘ _ TIME

LEG TOE p-- 1? POSITION

A d0

O ‘ TIME

4-D“ ’ DOUBLE-LEG SUPPORTlNG SINGLE~LEG 4 PHASE SUPPORTING

+ PHASE FREE LEG HEEL FREE LEG HEEL LANDING LIFTING SUPPORTING SUPPORTING LEG LEG HEEL HEEL LANDING FREE LEG TOE LIFI‘ING

LIFI'ING SUPPORTING LEG TOE LANDING

FIG. 8

STANDARD GAIT NO.1

INITIAL FREE LEG b0 FINAL FREE LEG POSITION POSITION AND ----> Y (LEFT) AND ORIENTATION ORIENTATION E9,“



FIG.9

SUPPORTING LEG HEEL

POSITION t 4 XZIYID “ C1

t1 t2v t3 . —_

0 TIME INITIAL FREE :_

LEG TOE POSITION P

W II

0 TIME}

SINGLE-LEG DOUBLE‘LEG SUPPORTING PHASE SUPPORTING PHASE

STANDARD GAIT NO. 2

INITIAL FREE LEG b2 (LEFT) ‘ FINAL FREE LEG POSITION I-.---———-u>

POSITION AND ORIENTATION Y AND ORIENTATION I

\

<I=u0 \ TO V = X( )



SUPPORTING LEG HEEL t4

Xzmp POSITION C2

H t2 ‘ t3 0 V

INITIAL FREE I I TIME LEG TOE p

POSITION Yzmp I d2

0 1 TIME

'- I

DOUBLE-LEG SIN GLE-LEG SUPPORTING SUPPORTING PHASE PHASE

FIG. 12 DEMAND GAIT (3RD GAIT)

INITIAL FREE b 3 LEG POSITION y (LEFT) FINAL FREE LEG AND 2 03 I POSITION AND ORIENTATION 1% ORIENTATION

__ = x (To)



FIG. 13

SUPPORTING X LEG HEEL t 4 mm 0 POSITION 05

t1 t2 I I3! INITIAL FREE 0 TIME LEG TOE “(1 POSITION p

Yzmp M d?)

O f TIME

DOUBLE~LEG SUPPORTING PHASE SINGLE-LEG » I t SUPPORTING

PHASE FREE LEG TOE FREE LEG LIFTING SUPPORTING HEEL LIFTING LEG TOE LANDING

SUPPORTING LEG HEEL FREE LEG LANDING HEEL

LANDING SUPPORTING LEG HEEL LIPTING

U.S. Patent 0a. 9, 2001 Sheet 10 0f 38 US 6,301,524 B1

FIG. 14

{ ENTRY ) S100

J SELECT AS BASE GAIT ONE STANDARD GAIT WHOSE DIRECTLY- DETERMINED PARAMETERS ARE CLOSE TO DEMANDED VALUES

S102 J

SELECT STANDARD GAITS SEPARATELY ONLY ONE OF WHOSE DIRECTLY- DETERMINED PARAMETERS IS DIFFERENT FROM BASE GAIT

S104

SUBSTITUTE DEMANDED VALUES FOR MIXED GAIT DIRECTLY-DETERMINED PARAMETERS

CALCULATE MIXED GAIT DEPENDENT PARAMETERS USING EQUATION FOR J PARAMETER CALCULATION

S106

RETURN


FIG. 15

m w m D 2. m u _ _ mm L _ _ _ A n _ >

_ _ w m _ m IITIIILWILLIIIJMI. _ _ _ _ 0

_ _ _ _

_ L. ._r J_, a _ _ D N_ u

_ _ W m r» _ d|||._ llllklisivwllapll! 1. 1 _ a, _

M m _ _ T _ m T _ _ _ _

m m “m, u u _ m S b b .ilmwil?iliimiml _< _ _ 2 < L L n mm“

m m

INITIAL FREE LEG FOOT ORIENTATION a

INITIAL FREE LEG FOOT TO-AND-FRO POSITION b


FIG. 16

PARAMETER

77*; Y" STANDARD GAIT CANDIDATE 2 STANDARD GAIT STANDARD GAIT DEMANDED '

BASE GAIT VALUE CANDIDATE 1 CANDIDA TE 3

FIG. 17

( ENTRY I

( S200

CALCULATE ZMP AT TIME t BASED ON MIXED GAIT PARAMETERS

S202

CALCULATE FEET POSITION AND ORIENTATION AT TIME t BASED ON MIXED GAIT PARAMETERS

( S204

CALCULATE BODY HEIGHT AT TIME t BASED ON FEET POSITION/ORIENTATION AT TIME t, AND HORIZONTAL BODY POSITION AT TIME t- A t

S206

CALCULATE MIXED GAIT HORIZONTAL BODY POSITION AT TIME t BASED ON BODY POSITIONS AT TIME t vOF SELECTED STANDARD GAITS (INCLUDING BASE GAIT) USING EQUATION FOR GAIT MIXING

( RETURN )

U.S. Patent Oct. 9, 2001 Sheet 13 0f 38 US 6,301,524 B1

FIG. 18

START

CONDUCT PROCEDURES FOR CALCULATING MANIPULATED VARIABLE OF DOUBLE-LEG W 3300 COMPLIANCE CONTROL

CALCULATE DESIRED JOINT ANGLES S302 BASED ON FEET POSITION/ORIENTAT ION m AND BODY POSITION AND ORIENTATION

DETECT INCLINATION OF ROBOT, AND CORRECT DESIRED POSTURE / S304 (DESIRED JOINT ANGLES) TO ADJUST FOR INCLINATION

CONTROL JOINTS TO TRACE rV3306 DESIRED JOINT ANGLES

RETURN

U.S. Patent Sheet 14 0f38 Oct. 9, 2001

FIG. 19

SUBROUTINE FOR CALCULATING DOUBLE-LEG COMPLIANCE MAN IPULATED VARIABLE

READ OUTPUT OF 6-AXIS FORCE J /S 400 AND TORQUE SENSORS

CALCULATE ACTUAL ZMP POSITION S402 (ACTUAL FLOOR REACTION FORCE J CENTRAL POINT) BASED ON OUTPUT OF 6—AXIS FORCE AND TORQUE SENSORS

COMPARE IT WITH DESIRED ZMP POSITION, AND CALCULATE DIRECTION OF DEVIATION AND AMOUNT OF DEVIATION X

FEET MANIPULATED VARIABLE = AMOUNT OF DEVIATION X * COMPLIANCE GAIN Kf * FORCE F

DEVIATE DESIRED FEET POSITION AND1/S4O8 ORIENTATION IN RESPONSE TO FEET MANIPULATED VARIABLE

( RETURN )

US 6,301,524 B1

S404

S406


FIG. 20

START S8500 STORE BASE GAITS AND GAIT PARAMETER SEN SITIVITIES PREPARED BY OFFLINE COMPUTER IN MEMORY

CALCULATE AND STORE FINAL BODY POSITIONS/x5502 AND VELOCITIES IN STANDARD GAITS

t = 0 S504 S5508

S5506 WAIT FOR TIMER INTERRUPT (AT EVERY CONTROL CYCLE)

00 S510 14 g yes t = 0 /s512 585

AT GAIT READ DEMANDED VALUES SWITCHING FOR DIRECTLY _ DETERMINED

PARAMETERS IN NEW CUR RENT GAIT

CONDUCT PROCEDURES FOR /S516 GAIT MIXING

SUBSTITUTE MIXED GAIT PA- /$518 RAMETERS (TABULATED DATA) FOR DESIRED GAIT PARAMETERS (TABULATED DATA)

CONDUCT PROCEDURES FOR CALCULATING / S520 LNSTANTANEOUS VALUES OP DESIRED GAIT

t=t+At /S522

END


FIG. 21

( ENTRY )

SELECT BASE GAIT WHOSE DIRECTLY DETERMINED PARAMETERS ARE CLOSE TO N600 DEMANDED VALUES

SUBSTITUTE DEMANDED VALUES FOR MIXED“ GAIT DIRECTLY-DETERMINED PARAMETERS $602

CALCULATE MIXED GAIT DEPENDENT PARAMETERS USING EQUATION FOR ‘@5604 PARAMETER CALCULATION

RETURN


FIG. 22

I ENTRY )

CALCULATE ZMP AT TIME t BASED ON MIXED GAIT PARAMETERS "v 3700

CALCULATE FEET POSITIONS AND ORIENTATIONS AT TIME t BASED‘w 5702 ON MIXED GAIT PARAMETERS

CALCULATE BODY HEIGHT AT TIME t BASED ON FEET POSITION/ORIENTATION ’\/S704 AT TIME t AND HORIZONTAL BODY POSITION AT TIME t-At USING BODY HEIGHT DETERMINATION METHOD

CALCULATE MIXED GAIT BODY HORIZONTAL POSITION AT TIME t BASEDA/ 3706 ON BODY POSITIONS AT TIME t OF SELECTED STANDARD GAITS USING EQS.2

@TE


FIG. 23'

START S800

é STORE STANDARD GAITS AND GAIT PARAMETER SENSI TIVITIES PREPARED BY OFFLINE COMPUTER IN MEMORY

CALCULATE AND STORE FINAL BODY POSI- “S802 TIONS AND VELOCITIES IN STANDARD GAITS

S806 WAIT FOR TIMER INTERRUPT g (AT EVERY CONTROL CYCLE)

AT GAIT g SWITCHING READ DEMANDED VALUES FOR

DIRECTLY-DETERMINED PARAME TERS IN NEW CURRENT GAIT

CONDUCT PROCEDURES FOR GAIT MIXING (SELECT STANDARD S816 GAITS TO BE MIXED, DETERMINE L/ WEIGHT AND GENERATE MIXED GAIT PARAMETERS) S818

SUBSTITUTE MIXED GAIT PARAMETERS (TABULATED DATA) FOR DESIRED GAIT PARAIVIETERS (TABULATED DATA)

CONDUCT PROCEDURES FOR CALCULATING A INSTANTANEOUS VALUES OF DESIRED GAIT S820

t=t+At H8822


FIG. 24

( ENTRY )

SELECT ONE STANDARD GAIT WHOSE},\/S9OO DIRECTLY~DETERMINED PARAMETERS ARE ' CLOSE TO DEMANDED VALUES AS BASE GAIT

SELECT STANDARD GAIT SEPARATELY ONLY

ONE OF WHOSE DIRECTLY-DETERMINEDf\/S902 PARAMETERS (HAVING NO PARAMETER SENSITIVITY) IS DIFFERENT FROM BASE GAIT

SUBSTITUTE DEMANDED VALUES FOR MIXED S904 GAIT DIRECTLY-DETERMINED PARAMETERS

CALCULATE MIXED GAIT DEPENDENT S906 PARAMETERS USING EQUATION FOR"'\/ PARAMETER CALCULATION

( RETURN I

gait generation system of legged mobile robot

Documents