United States Patent
`
`[191
`
`[11]
`
`4,407,132
`
`Kawakatsu et al.
`
`[45]
`Oct. 4, 1983
`
`[54]
`
`CONTROL APPARATUS AND METHOD
`FOR ENGINE/ELECTRIC HYBRID
`VEHICLE
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`[75]
`
`[73]
`
`Inventors: Shiro Kawakatsu, Suita; Shoji Honda,
`Toyonaka, both of Japan
`
`Assignee: Daihatsu Motor Co., Ltd., Ikeda,
`Japan
`
`[21]
`
`Appl. No.: 330,433
`
`[22]
`
`Filed:
`
`Dec. 14, 1981
`
`Related U.S. Application Data
`
`[63]
`
`Continuation of Ser. No. 123,057, Feb. 25, 1980, Pat.
`No. 4,305,254.
`
`[51]
`[52]
`
`[53]
`
`Int. Cl.3 ............................................ .. F02B 73/00
`U.S. Cl. ...................................... .. 60/716; 60/718;
`180/65 B
`Field of Search ............... .. 60/698, 706, 709, 711,
`60/716, 718; 180/65.2, 65.1; 290/17, 45
`
`3/1970 Yardney ........................... .. 180/65.2
`3,503,464
`
`3,923,115 12/1975 Helling . . . . . .
`. . . . .. 180/65.2
`4,042,056
`8/1977 Horwinski ................... .. 180/65.2 X
`
`Primary Examiner—Allen M. Ostrager
`Assistant Examiner—Stephen F. Husar
`Attorney, Agent, or Firm—Darby & Darby
`
`[57]
`
`ABSTRACT
`
`A hybrid vehicle comprises an internal combustion
`engine and a motor/generator, which are controlled by
`a microcomputer. The internal combustion engine is
`rendered capable of a running operation in a region of a
`better
`fuel consumption characteristic. Outside the
`above described region,
`the motor is cooperatively
`driven with the internal combustion engine to provide a
`driving torque or only the motor is energized by a bat-
`tery to provide a driving torque. On the other hand,
`when the hybrid vehicle is driven with a torque smaller
`than a predetermined lower limit value of the torque of
`the internal combustion engine, the redundant torque is
`used to drive the generator, so that a regenerative
`power is absorbed by the battery.
`
`1 Claim, 22 Drawing Figures
`
`27
`
`SPEED '
`JENSDR
`
`TR/INS -
`MISSION
`
`
`
`ONE-WA)“
`
`CLUTCH
`
`
`
`,_L_
`1
`I
`- - - -15‘HUNT|-
`1.- _.J
`
`II
`ll
`19
`—_.I—_._I
`63-.4" ourPuT .
`' no/er
`'
`1.-- ,.,__J
`V
`
`s5-_J;;,;‘6,, 5,“
`L _ _ _ _ ___J
`g
`.j-.
`,:~.
`.~. :
`
`Page 1 of 27
`
`FORD 1488
`
`Page 1 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 1 of 15
`
`4,407,132
`
`
`
`FULL THROTTLE
`
`TORQUEIkg-rn]
`
`,B
`
`
`
`:APPROXlMATE EOUA TION
`- ---MEASUREMENT
`
`Page 2 of 27
`
`FORD 1433
`
`Page 2 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 2 of 15
`
`4,407,132
`
`FIG. 2
`
`DEFRESSED AMOUN
`OF ACCELERATING
`PEDAL 10073
`
`omssssb AMOUNT
`or ACCEIERA nm;
`PEDAL 50%
`
`(0IL PR£ssuR£) BRAKING PEDAL
`
`BRA KING PEDAL
`
`(OIL P§ESSURE)
`
`Page 3 of 27
`
`A
`
`FORD 1433
`
`Page 3 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 3 of 15
`
`4,407,132
`
`235men
`
`zomzmw
`
`.:s__-.,.=s
`
`$33
`
`«M3519
`
`.2393.»
`
`20?V-.<3m8<
`
`
`
`1IIIIII...
`
`
`_rm»....N..m..3A9
`0G@II
`
`
`
`
`
`ul|l__.53.»__SmSoT13 _IIl.LL.rII1IIL
`
`Page 4 of 27
`
`FORD 1488
`
`Page 4 of 27
`
`FORD 1488
`
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 4 of 15
`
`4,407,132
`
`
`
`S209kwiajfik
`
`5
`
`.3
`
`3
`
`mmsofloum¢E.3>
`
`M65.3..
`
`. .u:w\a..3.5%5_R3MMRQUEECM
`
`Page 5 of 27
`
`FORD 1488
`
`Page 5 of 27
`
`FORD 1488
`
`
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 5 of 15
`
`4,407,132
`
`FIG.
`
`6
`
`THROTTLE
`OPENING DEGREE 700%
`
`
`
` AV
`
` "‘\\\\"C3))?
` HIIY
`
`
`
`Page 6 of 27
`
`FORD 1488
`
`Page 6 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 6 of 15
`
`4,407,132
`
`Page 7 of 27
`
`%
`
`FORD 1433
`
`Page 7 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1933
`
`Sheet7 of 15
`
`4,407,132 %
`
`FIG.
`
`10
`
`START
`
`READ DATA
`
`I0!
`
`(Vn, n. TR, BF)
`
`N 7n
`
`-
`
`‘
`
`
`Page 3 of 27
`
`FORD 1433 T
`
`Page 8 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 8 of 15
`
`4,407,132
`
`FIG.
`
`/13
`
`.111
`
`N0
`
`TES
`
`112
`
`YES
`
`0
`
`
`
`
`
`0
`"L
`
`/75
`
`/16
`
`7é(N)'=Tel(N.)
`7"7(N)-Tel (N)'Tr
`
`V
`
`DETERHINE 0llTPUT
`FOR CONTROL OF
`ENGINE
`
`T- COMMAND
`ENGINE CONTROL
`
`DETERMINE ourmr
`
`FOR CONTROL OF
`GENERATOR
`
`.
`
`,,-,
`
`8
`
`,1
`
`I19
`
`V
`
`COMMAND
`GENERATOR CONTRO
`
`we ROUTINE
`ENGIN START
`
`START
`
`P399 9 Of 27
`
`FORD 1433
`
`Page 9 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 9 of 15
`
`4,407,132
`
`FIG.
`
`IID
`
`9
`
`IZI
`
`NO
`
`YES
`
`/23
`
`NO
`
`YES
`
`/24
`
`I22
`
`308 ROUTINE
`ENGINE STOP
`
`I25
`
`NO
`
`
`
`'
`
`/32
`
`reumgrrg 7au(u
`
`"5
`
`YES‘
`
`I26
`
`
`
`0 E
`
`(N) - Teu (N)
`Tn(N)-Tr-Teu (N)
`
`SUB ROUTINE
`
`ENGINE STOP
`
`0
`
`N0
`
`I33
`
`N0
`
`rss
`
`fl
`
`1‘
`
`I34
`
`SUB ROUTINE
`
`ENGINE STOP
`
`DETERMINE ourrur
`FOR £‘0NTROL or
`ENGINE
`
`9
`
`/27
`
`COMMAND
`
`ENGINE CONTROL
`
`I28
`
`DETERMINE oum/r
`
`FOR CONTROL OF
`MOTOR
`
`I
`
`I29
`
`COMMAND
`MOTOR CONTROL
`
`sun ROUTINE
`ENGINE START
`
`'3”
`
`m
`
`@
`
`Page 10 of 27
`
`FORD 1488
`
`Page 10 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 10 of 15
`
`4,407,132
`
`mzcaeami.
`
`
`
`«Ea.MZGZM
`
`MEEDQM§n
`
`
`
`mot.wzszm
`
`m:6H
`
`Page 11 of 27
`
`FORD 1488
`
`Page 11 of 27
`
`FORD 1488
`
`
`
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 11 of 15
`
`4,407,132
`
`201
`
`N0
`
`FIG.
`
`/ZA
`
`202
`
`COMMAND
`
`ENGINE ENABLE
`
`COMMAND
`STARTER INITIATE
`
`205
`
`206
`
`TIMER T SET
`(1')
`
`7
`
`‘
`
`209
`N0
`
`conmuvo .
`
`STARTER sroP
`
`204
`
`no
`
`.
`207
`
`YES
`COMMAND
`STARTER STOP
`
`77"“? T ]
`COUNTER c RESET
`
`208
`
`co‘:/~r1.se c
`( 1 = t +1 )
`
`
`
`comm/vo
`
`ENGINE DISABLE
`
`SET EMST
`
`START
`
`Page 12 of 27
`
`FORD 1488
`
`
`
`E
`
`203
`
`No
`
`Page 12 of 27
`
`FORD 1488
`
`

`
`US. Patent
`
`Oct. 4, 1983
`
`Sheet 12 of 15
`
`4-,407,132
`
`FIG.
`
`/23
`
`‘
`
`J0!
`
`N0¢ _
`
`302
`
`‘
`
`.
`
`”
`
`‘ J03
`
`DETERMINE ourm
`FOR comma;
`or ENGINE
`
`COMMAND
`ENGINE CONTROL
`
`304
`
`.305
`
`30K
`
`TIMER T1 ssr
`
`’
`
`.
`
` No
`
`753
`
`COMMAND
`
`ENGINE DISABLE
`
`TIMER TI RESET
`
`307%
`
`
`
`Page 13 of 27
`
`FORD 1488
`
`Page 13 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 13 of 15
`
`4,407,132
`
`FI6.
`
`73,4
`
`£0!
`
`05
`
`a 405
`Te(N)-Telm)
`
`Te(N)-Teu(N)
`
`DETERMINE OUTPUT
`FOR CONTROL OF
`
`
`
`ENGINE
`
`.
`
`
` 402
`
`
`
`
`
`
`COMMAND
`
`ENOINE CONTROL
`
`SUB ROUTINE
`
`ENGINE START
`
`403
`
`404
`
`,0,
`
`E
`
`505
`
`
`
`
`TM =ra«<~»
`
`START
`
`
`
`
`
`FIG.
`
`:33
`
`
`
`
`
`DETERMINE OI/TPU
`
`F0/I amrkot or
`
`GNERATOR
`
`COMMAND
`
`
`
`GENERATOR CONTROI
`
`
`
` 504
`
`Page 14 of 27
`
`FORD 1433
`
`Page 14 of 27
`
`FORD 1488
`
`

`
`US. Patent
`
`Oct. 4, 1983
`
`Sheet 14 of 15
`
`4,407,132
`
`
`
`560
`
`Tm (N) = Tnu (N)
`
`603
`DETERMINE OUT‘
`FOR CONTROL OF
`
`MOTOR
`
`COMMAND
`
` 604
`
`MOTOR CONTROL
`
`Page 15 of 27
`
`FORD 1433
`
`Page 15 of 27
`
`FORD 1488
`
`

`
`U.S. Patent
`
`Oct. 4, 1983
`
`Sheet 15 of 15
`
`4,407,132
`
`FIG. MA
`
`
`
`oven
`DISCHARGE
`3
`
`rmsr
`
`SET
`
`
`
`701
`
`"0
`
`703
`
`RESET ‘ "MST
`
`
`
`
`
`
`807
`
`mm
`
`HPERAIIIRE mp
`UE 7
`
`"0
`
`FIG.
`
`/43
`
`(IVER
`CHARGE ?
`
`
`
`
`
`004
`
`RESET GMST
`
`Page 16 of 27
`
`FORD 1488
`
`Page 16 of 27
`
`FORD 1488
`
`

`
`1
`
`4,407,132
`
`CONTROL APPARATUS AND METHOD FOR
`ENGINE/ELECTRIC HYBRID VEHICLE
`
`This is a continuation of application Ser. No. 123,057
`filed Feb. 25, 1980, now U.S. Pat. No. 4,305,254 filed
`Dec. 15, 1981.
`BACKGROUND OF THE INVENTION
`
`s
`..
`,
`1. Field of the Invention.
`The present invention relates to an apparatus and
`method for controlling an engine/electric hybrid vehi-
`cle. More specifically, the present invention relates to
`an apparatus and method for controlling an engine/e-
`lectric hybrid vehicle for performingan improved fuel
`consumption efficiency.
`,
`2. Description of the Prior Art
`An electric vehicle has been considered as one of the
`most effective transportation means by virtue of free-
`dom from pollution as compared with vehicles employ-
`ing any other conventional prime movers. On the other
`hand, however, such electric vehicle suffers..from vari-
`ous disadvantages that a long period of time is required
`for charging a battery, a continual running distance and
`time are short and so on. In view of the-foregoing, an
`engine/electric hybrid vehicle implemented as an inter-
`nal combustion engine borne electric vehicle has been
`proposed and put into practical use for the purpose of
`eliminating the above described disadvantages without
`losing the advantages proper of an electric vehicle.
`Naturally such engine/,electric hybrid vehicle consumes
`a fuel in an engine running mode and consumes electric
`power in a motor running mode.
`With the recent aggravation of an oil situation,:-an
`automobile of the leastpossible fuel consumption has
`been desired. In addition, it is also desired. that an ex-
`haust gas is purer inasmuch as such an exhaust gas from
`an engine is one cause of air pollution. It has been well-
`known that an exhaust. gas from an engine is purer when
`an engine efficiency is better.
`
`SUMMARY OF THE INVENTION '
`‘ Briefly described, the present invention comprises a
`hybrid vehicle including an internal combustion engine
`and a motor being energized by a battery, adapted such
`that only the internal combustion engine is rendered
`capable of a running: operation in a region of a better
`fuel consumption characteristic and outside the above
`described region the motor is mainly used as a prime
`mover. Preferably, the vehicle is further adapted such
`that in a region where a required torque is larger than an
`upper. limit of a predetermined torque range allowing
`for a running operation of the internal combustion en-
`gine the internal combustion engine is rendered capable
`of a running operation at the upper limit of the allow-
`able torque range at least at. a portion of such range,
`while the deficient torque is obtained from the motor
`being energized by the battery. Preferably, the vehicle
`is further adapted such that if the required torque can be
`obtained only by the internal combustion engine, only
`the internal combustion engine isused asa prime mover.
`According to the present invention, since theintemal
`combustion engine is run only in a region where a fuel
`consumption is less or a thermal efficiency is better, a
`fuel efficiency of the internal combustion engine is im-
`proved. Accordingly, a hybrid. vehicle is provided
`which is most suited for a demand of suppressing a fuel
`consumption in the light of the recent aggravation of an
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`oil situation. Meanwhile, outside the above described
`running operation allowable range of the internal com-
`bustion engine, the motor is also used as a prime mover.
`As a result, a- requied number of revolutions and re-
`quired torque can be attained throughout a full range
`with stability.
`.
`According to a preferred embodiment of the present
`invention,’the motor is also structured to be operable as
`a generator and the vehicle is further adapted such that
`inthe case where the number of revolutions is within a
`
`predetermined revolution number range allowing for a
`running operation of the internal combustion engine
`and the required torque is lower than a lower limit
`value of the torque range allowing for a running opera-
`tion of the internal combustion engine and the sign
`thereof is plus, the internal combustion engine is run ."
`with the lower limit value of the above described allow- ‘
`able torque range and the redundant torque is absorbed
`by the generator, so that the output generated by the
`generator is regenerated to the battery. Therefore, a
`hybrid “vehicle is provided wherein a demand of saving
`energy can be achieved. More specifically, even in the
`case where the required torque is smaller than the lower
`limit of the above described allowable torque range of
`the internal combustion engine, degradation of a fuel
`consumption characteristic is avoided by running the
`internal combustion engine with the lower limit torque
`and theredundant torque is absorbed by the generator,
`with the result that always a torque corresponding to a
`the required torque is obtained. The generated output
`obtained as a result of running of the generator is regen-
`erated to the battery Without being wastefully con-
`sumed and loss of generated electric power is avoided.
`As aresult, as a whole, the demand of saving energy can
`be met.’
`,
`Accordingly, a principal object of the present inven-
`tion is to provide an improved apparatus and method
`for controlling a hybrid vehicle.
`Another object of the present invention is to provide
`a hybrid vehicle wherein a fuel consumption by an
`internal combustion engine can be minimized.
`A further object of the present invention is to provide
`a hybrid vehicle which achieves the best energy saving
`effect as a whole.
`
`Still a further object of the present invention is to
`provide a hybrid vehicle, wherein an exhaust gas ex-
`hausted from the internal combustion_engine is purer.
`These objects and other objects, features, aspects and
`advantages of the present invention will become more
`apparent from the following detailed description of the
`present, invention when taken in conjunction with the
`accompanying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a graph showing one example of a fuel
`consumption characteristic of a certain type of an inter-
`nal combustion engine, particularly a diesel engine, for
`explaining the principle of the present
`invention,
`wherein abscissa indicates the number of shaft revolu-
`tions (X103 rpm) and the ordinate indicates the axis
`torque (kg.m);
`FIG. 2 is a graph showing the respective operating
`regions for explaining the principle of the present inven-
`tion, wherein the abscissa indicates the number of shaft
`revolutions and the ordinate indicates the shaft torque;
`FIG. 3 is a block diagram showing one embodiment
`of the present invention;
`
`Page 17 of 27
`
`FORD 1488
`
`Page 17 of 27
`
`FORD 1488
`
`

`
`4,407,132
`
`3
`FIG. 4 is a block diagram showing a preferred em-
`bodiment ,of a chopper circuit included in the FIG. 3
`block diagram;
`.
`FIG. 5 is,a schematic diagram showing one example
`of a_vo1tage follower for use in the FIG. 4 embodiment;
`FIG. 6 is a graph showing a relation of the throttle
`opening degree with respect to the number of revolu-
`tions and the torque of the internal combustion engine;
`FIG. 7 is a graph showing a relation of a second
`control amount and a third control amount with respect
`to the number of shaft revolutions and the torque
`Tm(N), Tg(N) of a motor/generator, wherein the ab-
`scissa indicates the, number of revolutions and the ordi-
`nate indicates the torque;
`.
`,
`.
`FIG. 8 is a graph showing a discharge characteristic
`of a battery, wherein the abscissa indicates the current
`and the ordinates indicates the voltage;
`FIG. 9 is a graph showing a charge characteristic of
`a battery, wherein the abscissa indicates the current. and
`the ordinate indicates the voltage;, and
`_.
`FIGS. 10A, 11A to 11E, 12A, 12B, 13A to 13C, 14A
`and 14B are flow diagrams for explaining the operation
`of the present invention.
`3
`'
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`‘
`
`5
`
`10
`
`I5
`
`20
`
`25
`
`4
`value Neu and a lower limit value Nel of the range of
`the number of revolutions of the engine. Meanwhile, it
`is pointed out that evenwithinthe region E a region
`where a fuel consumption is worse than 190(gr/PS-h) is
`included and furthermore it could—happen that some
`portion is within the range of the fuel cunsumption
`being less than 190(gr/PS-h) but outside the region E.
`The reason is that the curve of the fuel consumption
`does not necessarily coincide with the curve of the
`throttle opening degree characteristic and a region of a
`better thermal efficiency was selected in an approximate
`manner in determining the region E. According to the
`embodiment, only a motor/generator borne on the hy-
`brid~vehicle is.run as a motor to provide a prime mover
`within the regions M-1, M-2 and M-3. Meanwhile','al-
`though the region M-1 is a region exceeding the upper
`limit value Tmu(N) of a motoring torque Tm(N), the
`motor/generator is controlled such that the motoring
`torque is-used as the upper limit value (Tmu(N)) within
`the‘ above described region~M-1. The region M-2 is a
`region ‘where the number'of shaft revolutions N ob-‘
`tained responsive to the speed of the movement of the
`vehicle is smaller than the lower limit value Nel of the
`number of revolutions of the engine, whereas the region
`M-3 is'a region where the number of shaft revolutions N
`is larger than the‘ upper limit value Neu of the number of
`‘revolutions of the engine. Furthermore the region
`M+E showsia region where the above described num-
`ber of shaft revolutions N associated with the speed of
`the vehicle is larger than the lower limit value Nel and
`smaller than the upper limit value Neu, where the re-
`quired torque Tr is smaller than the upper limit value
`Tmu(N) of the motoring torque and is larger than "the
`upper limit value Teu(N) of the engine torque. Within
`the region M+E, both the internal combustion engine
`and the motor are used as a prime mover. Within the
`region G the above described m0tor/generator is run as
`a generator. Furthermore, the region E+G is a region
`where the numbersof shaft revolutions N associated
`with the speed of the vehicle is larger than the lower
`limit value Nel and smaller than the upper limit value
`Neu andlthe required torque Tr lies between the lower
`limit value Tel(N) and zero of the engine torque. Within
`the region E+G, the engine is run as a prime mover and
`the redundant torque is absorbed by running the mo-
`tor/generator as agenerator. If and when an engine and
`a motor/generator of an engine/electric hybrid vehicle
`are controlled in a manner unique to each mode in the
`respective modes shown in FIG. 2, an improved en-
`gine/electric hybrid vehicle can be provided in which a
`fuel consumption by the engine is minimized and the
`energy loss by the motor/generator is also minimized.
`FIG. 3 is a block diagram showing one embodiment
`of the present invention. The embodiment shown is
`directed to an engine/electric hybrid vehicle compris-
`ing an engine 1 and a motor/generator 3. The engine 1
`and the motor/generator 3 are coupled to be controlled’
`by a microcomputer 5. In particular, the motor/genera-
`tor 3 is coupled such that a chopper circuit 7 is con-
`trolled by the microcomputer 5.
`'
`The engine 1 is structured to exhibit a specific fuel
`consumption characteristic as shown in FIG. 1 and the
`output shaftof the engine 1 is coupled to .the shaft of the
`motor/generator 3 through‘a one-way-clutch 9. The
`output shaft of the motor/generator 3 is coupled to a
`transmission 13 through a manual clutch 11. The output
`shaft of the transmission.13 is coupled through a trans-
`mission means such as a differential gear to a wheel
`
`FIG. 1 is a graph showing one example of a fuel
`consumption characteristic of a given kind of,:an,inter-
`nal combustion engine (simply referred to as an engine
`hereinafter) for depicting the principle of the present 30
`invention, wherein the abscissa indicates the number of
`revolution of the shaft of the engine (X 103 rpm) an'd the
`ordinate indicates the shaft torque (kg.m). Such a graph
`showing a fuel ‘consumption characteristic is‘ well-
`known as a map of specific fuel consumption. "More 35
`specifically, by taking an example of the FIG. 1 graph,
`the fuel consumption or thermal efficiency is the best if
`and when the engine is runvwithin the range of the
`specific fuel consumption (gr/PS-h) being “l85”. The
`present invention performs such a control that an" en- 40
`gine borne on a hybrid vehicle is used within a region of
`a relatively better thermal efficiency based on the spe-
`cific fuel consumption as shown in FIG. 1, fof example
`only the engine is used as a" prime mover of the vehicle
`if and when the number of revolution and the torque 45
`reside in the range of the specific’ fuel ‘consumption
`being less than approximately 190 (gr/PS-h), for exam-
`ple, and only the motor is used as a prime mover or both
`the motor and the engine are used as a prime mover of
`the vehicle if and when the torque resides outside the 50
`above described range.
`FIG. 2 is another graph for depicting the principle of
`the present invention, wherein the abscissa indicates the
`number of revolution of the shaft and the ordinate indi-
`cates the shaft torque. Referring to FIG. 2, the principle
`of the present invention will be described in detail.
`More specifically, referring to FIG. 2, within the
`range of the region B (which is an approximate portion
`of the region of the specific fuel consumption (gr/PS-h)
`being less than “190”, for example) only an internal
`combustion engine borne on a hybrid vehicle is run as a
`prime mover. The region E is a region defined by an
`upper limit line of a curve representing a throttle open-
`ing degree characteristic running through a portion of
`the region of the specific fuel consumption being less 65
`than 190(gr/PS-h),
`i.e. a line of the throttle opening
`degree being 100%, and a line of the throttle opening
`degree being 50%, and also defined by an upper limit
`
`60
`
`55
`
`Page 18 of 27
`
`FORD 1488
`
`Page 18 of 27
`
`FORD 1488
`
`

`
`4,407,132
`
`6
`sensor 29 is applied to the microcomputer 5 through the
`interface 35.
`,
`
`shaft 15 and thus to a wheel 17 and to a wheel ‘shaft 19
`and thus to a wheel 21.
`‘
`
`An alternator 23 for charging a battery, not shown,
`for auxiliary components is coupled to the engine 1. As
`well known, the‘ alternator 23 generates a voltage of the
`magnitude associated with the number of revolutions of
`the engine 1. The output from the alternator 23 is ap-
`plied to an interface 25. The interface 25 is adapted to
`provide an output of three stages, for example, in associ-
`ation with the output voltage signal obtained from the
`alternator 23. More specifically,
`the interface 25 is
`adapted to provide a low level voltage of such as"0 V
`when the engine 1 has been brought to a stop, a medium
`level voltge when the engine 1 has been placed in an
`idling state, and a high level voltage when the engine 1
`has been" placed in a relatively high speed revolution
`state as compared with the idling state. The output from
`the interface 25 is applied to the microcomputer 5 as one
`input thereto.
`K
`._
`.
`_
`A speed sensor 27 and a position sensor 29 are opera-
`tively coupled to. the transmission 13. The speed sensor
`27 is operatively coupled to the output shaft of the
`transmission 13, for example, so that pulses of a pulse
`repetition frequency associated with the number of
`revolutions Nv determined as a function of the speed of
`the vehicle. More specifically, a cable, not shown, of a
`speed meter is coupled to the output shaft of the~trans-
`mission 13 for the purpose of detecting the speed of the
`vehicle and the speed sensor 27 is structured to generate‘
`pulses of a pulse repetition frequency associated with
`the number of revolutions Nv responsive to the rotation
`of thecable of the speed meter. The number of revolu-
`tions Nv(rpm) determinable as a function of the speed of
`the vehicle has been unified under the Japanese Indus-
`trial Standard, for example, such that the number of
`revolutions may be the same for the same speed in any
`types of the vehicles. The Japanese Industrial Standard
`stipulates Nv=637><V/60(rpm). More specifically,
`according to the Japanese Industrial Standard‘,
`it has
`been stipulated that the number of revolutions Nv de-
`terminable as a function of the speed of the vehicle may
`be 637 rpm in the case where the speed V of the vehicle
`is 60 km/h. Meanwhile, the number of revolutions Na
`of the output shaft of the transmission 13 and the num-
`ber of revolutions Nv associatedwith the speed of the
`vehicle
`has
`a
`relation
`defined
`as Na= 100-
`0>< id XNv/637Xr, where the id denotes a gear ratio of
`a differential gear, ‘not shown, and r is an effective radi-
`us(m) of a tire of the wheel 17 or 21. Accordingly, the
`number of revolutions Na_ of the output shaft of the
`transmission 13 is given as unique to each vehicle. The
`speed sensor 27» provides through an interface 33 to the
`microcomputer 5 pulses of a pulse repetition frequency
`two times or four times the number of revolutions Nv
`associated with the speed of the vehicle. For example,
`the revolution number pulse fed from the speed sensor
`27 to the microcomputer 5 is of 120 Nv/second or 240
`Nv/second. The position sensor 29 comprises a micro-
`switch adapted to be turned on or off responsive to a
`gear ratio (speed change ratio) to which the transmis-
`sion gear has been selected. More specifically, if five
`forward speed drives and a rearward drive can be se-
`lected by the transmission 13, then six microswitches
`are provided in the position sensor 29. Thus if and when
`one of the gear ratios is selected by and the transmission
`13, then the corresponding microswitch is ‘turned on.
`The signal of the selected microswitch of the position
`
`5
`
`10
`
`15
`
`20
`
`30
`
`35'
`
`The engine/electric hybrid vehicle also comprises‘ an
`accelerating pedal 37 and a braking pedal 39. The accel-
`erating-pedal 37 is coupled to an acceleration circuit 41,
`which comprises a potentiometer for generating a volt-
`age associated with a depressed or displaced amount of
`the accelerating pedal 37. The voltage associated with
`the depression of the accelerating pedal 37 is applied to
`the microcomputer through an interface 43. On the
`other hand, the braking pedal 39 is coupled to a braking
`circuit 45. The braking circuit 45 comprises a pneumatic
`circuit for providing a braking force and a pressure
`‘sensor of the pneumatic circuit for providing a voltage
`associated with depression of the braking pedal 39 and
`thus pressure of the braking pneumatic circuit. The
`voltage from the braking circuit is applied to the miro-
`computer 5 through an interface 47.
`The microcomputer 5 is also connected to receive
`through an‘ interface 53 a voltage which is proportional
`' tothe voltage of the battery 49. The microcomputer 5 is
`further"co°nnected to receive through an interface 51 a
`voltage which is obtained from a shunt resistor 52 inter-
`posed in a current path of the battey 49 and is propor-
`25 tional to the current flowing through the above de-
`scribed current path. A temperature sensor, not shown,
`is thermally coupled to the battery 49, so‘that a voltage
`which is‘proportional to the temperature of the battery
`49 is fed from the temperature sensor through an inter-
`face’ 54 to the microcomputer 5. As well-known, the
`‘ microcomputer 5 comprises an arithmetic logic unit
`501, a read only memory 503 including a program,»as to
`be depicted"subsequently with reference to FIGS. 10,
`11A to 11E, 12A, 12B 13A to 13C,~14A, and 14B»for
`controlling the operation of the arithmetic logic unit
`501, a random access memory 505 for storing data nec-
`essary for the arithmetic logic unit 501 and the like. The
`microcomputer 5 receives the data from various com-
`ponents described previously to make an operation to
`be described in detail subsequently, thereby to control
`the engine 1 and the motor/generator 3 (chopper circuit
`7). The microcomputer 5 receives from a data table 55
`implemented by a read only memory any data necessary
`for such control. The data table 55 will be described in
`detail subsequently.
`A fuel control 57 is coupled to the engine 1. In the
`case where the engine is a diesel engine, the fuel control
`57 comprises a butterfly valve, not shown, serving as a
`throttle, for adjusting an amount of air fed into an en-
`gine cylinder,
`for example, an injection’, pump, not
`shown, for controlling a fuel injected amount and for
`pressure supplying a fuel into the respective cylinders, a
`control apparatus for the injection pump such as a ser-
`' vomotor, not shown, and the like. In the case where the
`engine 1' is a gasoline engine, the fuel control 57 com-
`prisesa butterfly valve and a pulse motor for driving the
`same, for example, for controlling the opening degree of
`a carburetor, not shown, serving as a throttle of the
`engine. Although not shown, the engine 1 is further
`provided with an ‘enabling apparatus and a starting
`apparatus of the engine. In the case where the engine 1
`a diesel engine, the engine enabling apparatus comprises
`means for connecting a fuel line, means for enabling an
`injection pump and the like. Onthe other hand, in the
`case where the engine 1 is a gasoline engine, the engine
`enabling apparatus comprises means for connecting a
`fuel line, an ignition circuit and the like.‘ The engine
`starting apparatus may comprise a startermotor.
`3
`
`40
`
`45
`
`50
`
`55
`
`65
`
`Page 19 of 27
`
`FORD 1488
`
`Page 19 of 27
`
`FORD 1488
`
`

`
`7
`The microcomputer 5 makes the above described
`operation and provides control data to an output port
`59. The output port 59 is responsive to the thus obtained
`data to provide to the fuel control 57 a first control
`amount, i.e. a signal for controlling the opening degree
`of the throttle included in the above described fuel
`control 57. The output port 59 has a function for hold-
`ing the above described control signal until new further
`data is received from the microcomputer 5 at the fol-
`lowing control cycle. The microcomputer 5 also pro-
`vides to an output port 61 control data for controlling
`the motor/generator 3. The output port 61 is responsive
`to the thus provided control data to provide at least one
`of two voltage signals, i.e. a second control amount and
`a third control amount. One of the voltage signals, i.e.
`the second control amount is a control signal used when
`the motor/generator 3 is run in a motoring mode,
`whereas the other voltage signal, i.e. the third control
`amount is a control signal used when the motor/genera-
`tor 3 is run in a generator mode. The output port 61 also
`has a function for holding the previous control amount
`signal until new further control data is obtained from.
`the microcomputer 5, just as in case of the above de-
`scribed output port 59.
`FIG. 4 is a block diagram showing in detail the chop-
`per circuit shown in FIG. 3. The chopper circuit 7 may
`be structured in accordance with the teaching in U.S.
`Pat. No. 3,735,220, entitled “CONTROL CIRCUIT
`FOR A D.C. MOTOR” and issued May 22, 1973 to
`Renner et al. Although in the above referenced U.S.
`Pat. No. 3,735,220 the chopper circuit is coupled to
`directly receive the voltages associated with the depres-
`sion amounts of an accelerating pedal and a braking
`pedal, the FIG. 4'embodiment of the present application
`is coupled to receive the voltage signals . obtained
`through the output port 61 from the microcomputer 5.
`Since in the FIG. 4 embodiment any means for detect-
`ing the number of revolutions of the motor/generator 3
`provided in the above referenced U.S. Pat. No.
`3,735,220 is not necessary, as to be described subse-
`quently, such means has not been shown in FIG. 4.
`The chopper circuit 7 is also connected from the
`above described battery 49 and also from the motor/-
`generator 3. The motor/generator 3 comprises an arma-
`ture 301 and a field coil 303. A drive switch 701 in-
`cluded in the chopper circuit 7 is turned on responsive
`to depression of the accelerating pedal 37, for example,
`while a braking switch 703 is turned on responsive to
`depression of the braking pedal 39. The battery 49 is
`connected to the chopper circuit 7 through a fuse 705, a
`contact 707 of a protecting relay, the above described
`drive switch 701 and the braking switch 703. A current
`flowing through the armature 301 of the motor/genera-
`tor 3 is controlled by a thyristor 709 and is measured by
`a current transformer 711. The thyristor 709 is turned
`off through a cooperative operation of a thyristor 713
`and a capacitor 715, a reactor 717 and a diode 719 oper-
`atively coupled to the thyristor 713. A current flowing
`through the field coil 303 of the motor/generator 3 is
`fed through a thyristor 721 and a a polarity inverter 723
`and the current is detected by a current transformer
`725. The thyristor 721 is turned off through a coopera-
`tive operation of a thyristor 727 and a capacitor 729, a
`reactor 731 a diode 733 operatively coupled to the thy-
`ristor 727. The thyristors 709, 715, 721 and 727 are
`turned on as a function of the current pulses obtained
`from the corresponding pulse generators 735, 737, 739
`and 741, respectively. The armature 301 is shunted by a
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4,407,132
`
`8.
`flywheel diode 305 and the field coil 303 is shunted with
`flywheel diode 307 and 309, in a well known manner.
`The armature 301 is further coupled to a smoothing
`reactor 311 and a commutating reactor 313.
`The above described pulse generators 735 and 737,
`and 739 and 741, each comprising a blocking oscillator,
`are controlled by an armature current controller 743
`and a field current controller 745. The armature current
`detected by the direct current transformer 711 is ap-
`plied to adders 747, 757, 759 and 769, while the field
`current detected by the direct current transformer 725
`is applied to an adder 749.
`On the other hand, as described previously, the chop-
`per circuit 7 is supplied with an analog voltage for con-
`trolling a motor and an analog voltage for controlling a
`generator. More specifically, the above described out-
`put port 61 comprises digital/analog converters for
`converting the data from the microcomputer 5 into
`analog voltages. The outputs of the digital/analog con-
`verters 61a_ and 61b included in the output port 61 are
`applied to voltage followers 751 and 753, respectively.
`The voltage followers 751 and 753 serve to convert the
`voltages from the digital/analog converters 61a and 61b
`into such values as suited for the chopper circuit 7. The
`analog voltages obtained from the voltage followers
`751 and 753 are applied to the adder 747 and a limiter
`755, respectively. Theoutput of the limiter 755 is ap-
`p