United States Patent 15
`4,559,599
`Dec. 17, 1985
`[45} Date of Patent:
`Habuet al.
`
`[11] Patent Number:
`
`[54] OPTIMUM SHIFT POSITION INDICATION
`USING SUCCESSIVE TWO-DIMENSIONAL
`DATA MAPS
`
`[75]
`
`Inventors:
`
`Nobuo Habu; Kouichi Osawa;
`Yuuichi Kato; Michio Furuhashi;
`Taiyo Kawai; Junichi Saiki; Toshio
`Ito, all of Susono; Tsutomu
`Nakamura, Kariya, all of Japan
`
`[73] Assignees: Nippondenso Co., Ltd., Kariya;
`Toyota Jidosha Kabushiki Kaisha,
`Toyota, both of Japan
`
`4,411,174 10/1983 Yokoi et ab... ecseseeses 74/866
`1/1984 Meyerleet al.
`.
`4,428,257
`.- 74/866
`
`340/52 R
`4,438,423
`3/1984 Stier .......0.
`
`3/1984 Weber........00
`4,439,158
`434/71
`
`4,463,427 7/1984 Bonnetain et al. .......cc-se 364/442
`
`FOREIGN PATENT DOCUMENTS
`
`2748227 6/1978 Fed. Rep. of Germany .
`3128080
`2/1983 Fed. Rep. of Germany .
`6235
`1/1979 Japan .
`2091358
`7/1982 United Kingdom.............. 364/442
`
`Primary Examiner—Felix D. Gruber
`Attorney, Agent, or Firm—Cushman, Darby & Cushman
`
`[21] Appl. No.: 474,324
`ABSTRACT
`[57]
`[22] Filed:
`Mar. 11, 1983
`A shift indication apparatus having an engine rotation
`[30]
`Foreign Application Priority Data
`sensor, a throttle valve sensor, and a shift position sen-
`Mar. 18, 1982 [JP]—Japan ....sceseoreesacseseeecneers 57-43655
`sor, a microcomputer having a ROM and RAM for
`storing data corresponding to the engine speed,throttle
`valve openings, and the shift positions therein, and an
`indicator for indicating preferable shift positions to be
`performed by a driver in which a torque data map and
`a fuel consumption rate data map have stored in the
`ROMforcalculating various torque and fuel consump-
`tion rates so as to obtain preferable shift positions relat-
`ing to optimum fuel consumption rate in accordance
`with said data detected. With this construction, it be-
`comespossible for a driver to run his car in accordance
`with the indications of the shift operation on the indica-
`tor so as to enable the economical running of the car to
`be realized.
`:
`
`[51]
`
`Ente C14 cisccccsccsesesesssees B60K 41/18; GO9B 19/16;
`GO7C 5/08
`[52] US. Che cesssscscssssarsssseesenseeees 364/424.1; 340/52 D;
`364/442; 434/71
`[58] Field of Search............... 364/424.1, 442; 434/71;
`340/52 R, 52 D, 52 F
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,150,497 4/1979 Weber ....ccccsscesserenseestesereeene 434/71
`
`4,198,882 4/1980 Kienckeet al.
`.....scscssesseeee 74/866
`74/766 X
`4,294,341 10/1981 Swart .....
`
`340/52 F
`3/1982 Olivier ...
`4,320,381
`
`4,350,057 9/1982 Kishi et ab.
`.....cscssssecsseeseeees 74/866
`4,354,173 10/1982 Kuhn et al.
`340/52 F
`
`4,355,296 10/1982 Drone ......scssscssensseseeeres 340/52 R
`
`12 Claims, 4 Drawing Figures
`
`BUS
`
`
`
`
`
`UNIFIED 1003
`
`UNIFIED 1003
`
`1
`
`

`

`U.S. Patent
`
`Dec.
`
`17,1985
`
` Sheetlof3
`
`4,559,599
`
`FIG.
`
`|
`
`a
`
`7P
`
`ree|
`
`/
`
`6
`
`5
`
`ENGINE SPEED
`f SENSOR
`
`2
`
`___|SHIFT POSITION
`SENSOR
`
`
`
`
`
`:|R
`
`AM|M 9 10
`1/0 | ar UPeaeenaTDOWN
`
`
`
`3
`
`|
`
`;
`
`THROTTLE
`SENSOR
`
`A/D
`CONVERTER
`
`10a
`
`Ob
`
`
`
`
`
`
`THROTTLE
`VALVE.
`
`ENGINE
`
`
`
`2
`
`

`

`U.S. Patent Dee. 17, 1985
`
`Sheet20f3
`
`4,559,599.
`
`FIG. 2
`
` )
`
`6
`
`Ne(xiOrpm)
`
`5
`4
`3
`2
`ENGINE SPEED
`
`FIG. 3
`
`
`
`
`
`@ONINAdOSATIVAFILLOGHL
`
`A
`
`J
`
`tts ‘/
`
`/
`
`LLL /,
`
`
`
`
` (W1/B4)8FNGYOLSNIONA
`
`1
`
`5
`4
`3
`2
`ENGINE SPEED
`
`6
`
`Ne (xiOrpm)
`
`3
`
`

`

`U.S. Patent Dec. 17, 1985
`
`Sheet 3 of 3
`
`4,559,599
`
`fZ=
`
`97
`
`-dIANSNOOTNF
`
`3LVaNOL
`
`HOGVAS
`
`
`
`4
`
`
`
`

`

`1
`
`4,559,599
`
`OPTIMUM SHIFT POSITION INDICATION
`USING SUCCESSIVE TWO-DIMENSIONAL DATA
`MAPS
`
`15
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`Thepresentinvention relatesto a shift indication unit
`which can be used for an automotive vehicle having a
`manual
`transmission and for indicating to a driver
`change-speed operations to be performed relating to
`preferable shift position with respect to optimum fuel
`consumption, and a method of performing the optimum
`speed change operation so as to reduce fuel cost.
`2. Description of the Prior Art
`Recently, the situation and circumstances surround-
`ing supply of oils have deteriorated, and various re-
`search and developmentactivities have been made in
`response in an attempt to improveefficient utilization of 5)
`energy in each technicalfield in industry. Thesituation
`is the same in the autombile industry, where various
`research and development for improving engines to
`have better thermalefficiencies and for pursuing better
`methodsfor performing effective combustion offuel for
`vehicles with less fuel consumption rate have been un-
`dertaken. However, there is a problem that unless oper-
`ations including acceleration operation and shift opera-
`tion are included,it is not possible for driving operation
`to sufficiently demonstrate the improved fuel consump-
`tion performance thus reached.
`SUMMARY OF THE INVENTION
`
`2
`These and other objects and advantages of the pres-
`ent invention will become more apparent from the fol-
`lowing detailed description with reference to the ac-
`companying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`,
`
`FIG.1 is an overall construction of one embodiment
`of the shift indication apparatus according to the pres-
`ent invention,
`FIG.2 is one example of the characteristic curves of
`a torque data map stored in the ROM in the microcom-
`puter in FIG. 1 and
`FIG.3 is one example of the characteristics of a fuel
`consumption data map stored in the ROM in the mi-
`crocomputerin FIG.1.
`FIG. 4 is a programmed flow chart of the speed
`change operation indicating unit of FIG. 1 for the pur-
`pose of explaining the operation of the unit according to
`the present invention.
`DESCRIPTION OF THE PREFERRED
`' EMBODIMENT
`
`25
`
`40
`
`Referring to FIG. 1, the shift indication apparatus
`with a manual transmission according to the present
`invention comprises an engine speed sensor1 for detect-
`ing the engine speed and for producing pulse signals of
`a frequency proportional to the engine speed, a shift
`position sensor 2 for detecting the shift positions of the
`transmission, a throttle sensor 3 for detecting the open-
`ing degree of the throttle valve by means of, for in-
`stance, a potentiometer, an A/D converter 4 for.con-
`verting analog signals from the throttle valve sensor 3
`into digital signals, a microcomputer 5 for performing
`It is therefore a main object of the present invention
`various calculations in accordance with the different
`to provide a shift indication apparatus which is capable
`signals from the sensors, and an indicator 10 for indicat-
`of performing optimum running with a good fuel con-
`ing the result of the calculations.
`sumption rate by indicating to a driver preferable shift
`The microcomputer 5 further comprises an input-
`positions for the optimum fuel consumption during the
`/output port (I/O port) 6, a central processing unit
`running of the automotive vehicle.
`(CPU) 7, a read only memory (ROM)8, and a random
`It is another object of the present invention to pro-
`access memory (RAM) 9. In the microcomputer 5,
`vide a shift indication apparatus having a microcom-
`there is provided a bus BUS which communicates the
`puterincluding a speed changeinstruction indicator and
`I/O port 6 and the CPU 7, ROM 8, and RAM 9.
`a ROM in which predetermined torque and fuel con-
`The engine speed sensor 1 is mounted in a distributor
`sumption maps are stored so as to calculate and indicate
`(not shown) and the outputof the sensor is connected to
`on the indicator preferable shift positions corresponding
`the input of the I/O port 6 so as to transmit the output
`pulses to the microcomputer 5 through the I/O port 6
`to the optimum fuel consumption rate.
`It is still another object of the present invention to
`and to store the data corresponding to the engine speed
`provide a speed change operation and indication unit
`into the RAM 9. The output of the shift sensor 2 is
`having a microcomputer comprising a ROM and a
`connected to the input of the I/O port 6 so asto trans-
`mit the output signals thereof to the microcomputer 5
`RAM into which data corresponding to the ‘current
`through the I/O port 6 and to store the data from the
`engine speed and current shift position as well as throt-
`shift sensor 2 into the RAM 9. Similarly, the output of
`tle valve opening are stored and expected torque and
`the throttle sensor 3 is connected through the A/D
`fuel consumption rates are calculated from the data read
`from the RAM together with the predetermined maps.
`converter4 to the input of the I/O port 6 so as to trans-
`mit the output signals thereof to the microcomputer 5
`Accordingto one feature of the present invention, the
`through the A/D converter 4 and to store the data
`shift indication apparatus is characterized in that the
`corresponding to the throttle value opening into the
`unit comprises sensors for detecting the engine speed
`RAM9after converting from the analog signals into the
`and the opening of a throttle valve, meansfor calculat-
`digital signals. The input of the indicator 10 is con-
`ing an expected or assumed fuel consumption rate in
`nected to the output of the I/O port 6 so as to indicate
`order to generate the same driving horsepoweras that
`each preferable shift position correspondingto the opti-
`in the current car running conditions at a certain shift
`mum fuel consumption rate in accordance with various
`position adjacent to the particular shift position of the
`parameters calculated.
`;
`transmission at that time, means for comparing the cur-
`The indicator 10 includes a shift-up indicating lamp
`rent fuel consumption rate with the assumed fuel con-
`10a and a shift-down indicating lamp 100.
`sumption rate so as to select a preferable shift position
`The indicator 10 may be assembled by light emiting
`with the optimum fuel consumption rate, and means for
`diodes (LED)so as to perform shift-up and shift-down
`indicating to the driver shift operation instructions to
`indications by up and down directed arrow marks. Al-
`the preferable shift position.
`
`45
`
`60
`
`65
`
`5
`
`

`

`4,559,599
`
`5
`
`10
`
`20
`
`25
`
`30
`
`3
`4
`ternatively, the indicator 10: may also be replaced: with
`stored in the ROM8in the microcomputer5, in accor-
`other voice: combining circuit so as to announce the
`dance with the detected data corresponding to the en-
`shift operations by voice instead of the indications:
`gine speed Ne and the throttle valve opening @. In this
`Before explaining the operation of the apparatus ac-~
`case, assuming that the engine speed Nz is 3600 rpm and
`cording to the present. invention, reference must be
`the throttle valve: opening @ is 30 degrees, the torque
`made to the torque data map.shown in FIG..2 and the
`value Te=11 kg-m is determined from the cross point
`fuel consumption rate'data map'shown in FIG. 3: The
`on the torque curve T in the torque data map.
`torque data map indicative of torque curves T as shown
`Then in the next step 24, i.e. the torque determination
`in FIG. 2.has been stored in the ROM 8 in advance. The
`step is executed. In this step 24, a decision is made as to
`fuel consumption rate data map indicative of equal fuel
`whether or not the value of the torque T, thus calcu-
`consumption rate curves B as.shown in FIG. 3 has:been
`lated in the step 23 is larger than 0.05 kg-m, ie. the
`also stored in the ROM 8 in advance. In FIG. 2, each
`vehicle speed is in the middle of speed reduction orit is
`equal: torque curve T was prepared by plotting and
`close:'to the speed reduction.If the result of the decision
`connecting equal torque points on the graph. with re-
`is YES, the next step, fuel consumption search’ step 25,
`spect to the engine speed.vs. throttle valve opening. In
`is executed, if the result of the the decision is NO, the °
`FIG: 3, each fuel -consumption rate curve B was pre-
`operation of the main routine terminates. In the step 25,
`pared by plotting and connecting equal fuel consump-
`the fuel consumption data is read from the ‘equal fuel
`tion rate points on a graph obtained in advance. by ex-
`consumption rate curves B on the fuel data map shown
`periment data with respect to the engine speed and the
`in FIG. 3 which has been stored in the ROM 8 andfuel
`torques thus calculated.
`consumption rate is searched from the calculated torque
`In operation, the microcomputer 5 functions‘in such a
`T,. and the engine speed Ng.
`manner that
`it determines current torque from the
`' Namely,if the shift position is in the fourth speed,as
`torque data map stored in the ROM8andother: data
`the torque T. is 11 kg-m‘and the engine speed is 3600
`corresponding to the engine speed detected by the sen-
`rpm, the point F4 is obtained on the fuel consumption
`sor i and throttle valve opening detected by the throttle
`rate curves B.in the fuel consumption rate data map.
`sensor 3, determines: expected: fuel consumption: rate
`Since the point F4 is in the area of the fuel consumption
`from the fuel consumption rate:data map_also stored in
`rate Be=300 g/psh to 350 g/psh, the fuel consumption
`the ROM8and the torque thus. determined as. well as
`rate of the fourth speed is determined as 300 g/psh to
`the engine speed, and compares the fuel consumption
`350 g/psh in this case.
`rate thus determined with an assumed fuel consumption
`Then the next-horsepower‘calculation step 26 is exe-
`rate when speed change operation is performed from
`cuted. In this step 26, the horsepowerP is calculated in
`the currentshift position to the adjacentshift position in
`accordance with the following equation.
`accordance with a control program, whereby an in-
`struction signal for changing suitable shift position re-
`lating to optimum fuel consumption rate is generated
`from the microcomputerandit is indicated on the indi-
`cator 10.
`The operation of the shift indication apparatus will
`now be made with reference to the control program
`flow chart shown in FIG.4.
`--First ofall, the engine speed sensor 1 produces pulse
`signals proportionalto the engine speed during running
`of the automotive vehicle and transmits these signals to
`the microcomputer5. In this case, as shown in FIG.4,
`the operation of a main routine is started at a predeter-
`mined timing, e.g. periodical timing pulses from a timer
`(not shown) and the detection of the engine speed Ne
`from the sensor 1 is carried outandit is stored into the
`RAM9 at the step 20. Then, the engine speed N-is read
`from the RAM 9 and it is compared with a predeter-
`mined number N (=1000 rpm) to determine whether or
`not the Nz exceeds the value 1000 at the step 21. If the
`result of the decision is YES, the next step 22 is exe-
`cuted. Thatis, in the step 22, the reading in of the open-
`ing of the throttle valve is performed through the throt-
`tle sensor 3 and the A/D converter4. In the above case,
`if the result of the decision in step 21 is NO, the main
`routine is terminated by determining that the shift oper-
`ation is not necessary and the engine speed N-is read
`again at the predetermined timing and now the opera-
`tion returns to the step 20.
`In the step 22, the throttle valve opening 6 is detected
`by the throttle sensor 3 and is then stored in the RAM
`9 after conversion from the analog signalsinto the digi-
`tal signals through A/D converter 4. The next step 23,
`Le. the torque search step is executed. In this step, the
`torque T, is determined from the torque curves T on the
`torque data map as shownin FIG.2 and which has been
`
`P=driving power in ps
`where
`Ne=the engine speed in rpm
`Te=torque in kg-m
`In the step 27, the detected data from the shift posi-
`tion sensor 2 is stored in the RAM 9 in the microcom-
`puter 5 through the I/O port 6.
`In the step 28, a neutral position decision is per-
`formed. Thatis, the decision is made whetheror not the
`shift position stored in the step 27 is in the neutral posi-
`tion, i.e. whether or not SP=0 is determined.Ifit is not
`the neutral in this case, the step 29 for deciding the fifth
`speed is executed. On the other hand,if thé result of the
`decision is neutral, the main routine operation is termi-
`nated asit is not necessary to indicate the speed change
`operation.
`In the step 29, since the shift position SP is deter-
`mined asthe fifth speed or the upmostshift position, the
`assumed processing for shifting up operations shown in
`the steps 30 through 36 is skipped and now the opera-
`tion moves to the calculating step for the number of
`engine rotations at the time of the shifting down in the
`step 37.
`On the other hand,if the result of the decision in the
`step 29 is such thatthe shift position SPis not at the fifth
`speed, the next step 30 is executed. In this step 30, the
`engine speed N-+1 is calculated in the case of oneshift-
`up. In this case, the equation for calculating the engine
`speed Ne+1 is as follows;
`
`P=NeX T./716.2
`
`35
`
`45
`
`60
`
`65
`
`Ne+1=Ne X gear ratio of shift position SP + 1/gear
`ratio of shift position SP
`
`6
`
`

`

`.
`
`6
`currentshift position to the one step shifting up position
`SP 41 is preferable. In this case, it is preferable to pro-
`vide some delay time as shownin the step 43 so as to
`prevent the driver from confusion due to intermittent
`illuminations of the lamp of the indicator 10 within a
`short time when the fuel consumption rate is on the
`critical borderlines.
`On the other hand, if the result of the decision in the
`step 35 is NO,that is, the assumed fuel consumption rate
`be41 is larger than the current fuel consumption rate be,
`the operation now moves to the step 36. In this step 36,
`the decision is made whether or not the current shift
`position SPis the first speed. If the result of the decision
`is YESindicating that the current shift position is the
`first speed, the processing for the main routineis termi-
`nated as no shift-down operation is required, while if
`the resuit of the decision is NO, the operation now
`moves to the next step 37 for calculating the engine
`speed N-+1 at the one step shifting down position SP
`_1. In this step, the engine speed Ne+1 at the time of
`shifting down from the current shift position SP to the
`one step shifting down position SP — is calculated by
`the following equation;
`
`Ne—-1=NeX gear ratio of shift position SP 1/gear
`ratio of shift position SP
`
`Te) =PX716.2/Ne—1
`
`where, each unit indicated
`Te+ 1= kg/m
`P=ps, and
`Ne+1=rpm.
`Andnow the operation movesto the next step 33. In
`this step 33,
`the assumed fuel consumption rate is
`where, each unit of each parameter indicates
`searched from the data map stored in the ROM8in the
`microcomputer 5. Namely, one cross point is sought
`Ne_1=1pm
`from the engine speed Ne+.1 which wascalculated in the
`N-=rpm.
`From the engine speed Ne—1 calculated here andthe
`step 30 and the torque T,4.1 calculated in the step 32 on
`driving power which was calculated in the step 26, the
`the data map shownin FIG.4. From the fuel consump-
`tion rate indicated in the equal fuel consumption rate
`torque Te_1 is calculated by the following relationship
`curves B surrounding this point in the coordinate posi-
`in step 38;
`tions, the assumed fuel consumption rate be. can be
`found. For instance, assuming that the engine speed
`Ne41=2800 rpm and the torque T-+1=12.1 kg-m, the
`where, each unit of each parameter indicated
`cross point F5 can be obtained from the data map and
`this point F5 belongs to the area of the fuel consumption
`Te-1=kg-m,
`rate of 200 g/psh to 250 g/psh in the equal fuel con-
`P=ps,
`sumption rate curves B. Accordingly, since the one step
`N.-1=rpm.
`shifting up position SP +1, i.e. the current shift is the
`The torque thus calculated is compared with a prede-
`fourth speed, the assumed fuel consumption rate be+1
`termined value such as 0.05 kg-m in the step 45. If the
`when shifting up to thefifth speed, becomes 200 g/psh
`result of the decision in step 45 is YES, the operation
`to 250 g/psh.
`now movesto the fuel consumption rate search step 39,
`The assumed fuel consumption rate be+1 thus
`where the assumed fuel consumption rate be—1 in the
`searched (i.e., derived) in step 33 is compared with a
`one step shifting down position SP_1 is searched from
`predetemined value in the next decision step 34. Thatis,
`the data map in FIG.3 as in the step 33. Namely,if the
`the fuel consumption rate be+1 is determined whether
`engine speed Ne—1is 4600 rpm and the torque Te—;is 12.
`or notit is larger than 5000 g/psh. In this case, a large
`kg-m which were calculated in the steps 37 and 38, the
`number such as 60000 g/psh is inputted in the area
`cross point F3 is determined on the data map in FIG.4.
`abovethe full opened torque in FIG. 4. Accordingly,if
`Accordingly, in step 39, from the area of the equal fuel
`the result of the decision is NO, the assumed fuel con-
`consumption rate curve B of 350 g/psh to 400 g/psh on
`sumption rate be+1is compared and is determined in the
`which the cross point F3is situated, the assumed fuel
`next step 35 as to whether or notit is smaller than the
`consumptionrate be—1is searched to be foundin the one
`current fuel consumption rate be which was searched
`step shifting down position SP —}.
`(i.e., derived) in the step 25.
`With the one step shifting down position SP _| thus
`If the result of the decision is YES, that is, the as-
`obtained, i.e. the current shift position SP being as the
`sumed fuel consumption rate be+1 is smaller than the
`fourth speed, the assumed fuel consumption rate when
`current fuel consumption rate b,, the operation now
`shifting down to the third speed which is in the shift
`movesto the step 43 and the operation for indicating the
`position SP _; thereunder, becomes 350 g/psh to 400
`shift-up condition is performedin the step 44 after some
`g/psh, and then the next step 40 is executed.In this step
`delay time. Namely,in this step, the speed change oper-
`40,
`the fuel consumption rate be in the current shift
`ation indicating signal is applied to the indicator or |
`65
`position SP which was searched in the step 25 is com-
`display 10 from the microcomputer 5 through the I/O
`pared with the assumed fuel consumption rate be—1 .
`port 6. As a result, a particular lampin this case, a shift-
`Namely, the decision making is performed whether or
`up indicating lamp in the indicator 10, is illuminated,
`not the assumed fuel consumption rate be_; is smaller
`thus indicating to the driver that the speed change from
`
`4,559,599
`
`5
`where, each unit indicates: Ne =rpm, Ne+1= rpm,and
`the gearratio is a physical quantity which one of ordi-
`nary skill understands is dictated by the physical em-
`bodimentof the gears used (and which ratios are stored
`as data for use with a particular embodiment).
`After executing this step, the operation now movesto
`the step 31 for deciding the engine speed N-+1. In this
`step 31, a decision is made as to whether or not the
`engine speed N_+1 at the one step shifting up position
`SP ,1 is larger than 1000 rpm.In this case, if the result
`of the decision is NO, the processing for the main rou-
`tine is terminated as the shift operation is not necessary.
`However, if the result of the decision is such that the
`engine speed Ne41 is larger than 1000 rpm, the opera-
`tion now movesto the next step 32. In this step 32, the
`calculation of the torque T,+1 at the one step shifting up
`position SP +1 is performed.
`The calculation of the torque is performed in accor-
`dance with the following equation.
`
`Tet 1=PX716.2/Ne+41
`
`_0
`
`—_ 5
`
`20
`
`25
`
`35
`
`40
`
`45
`
`50
`
`60
`
`
`
`7
`
`

`

`— 0
`
`_ 5
`
`20
`
`25
`
`’
`
`7
`8
`than the current fuel consumption rate b,. If the result
`the true scope andspirit of the invention in its broader
`of the decision is NO which means that the be_1 is
`aspects.
`:
`Whatis claimed is:
`larger than the be, the processing for the main routineis
`terminated. On the other hand,if the result of the deci-
`1. An electronically controlled system in an internal
`sion is YES, meaning that the assumed fuel consump-
`combustion engine for indicating shift position for a
`tion rate be—1 is smaller than the current fuel consump-
`manual transmission thereof so as to maintain optimum
`tion rate be, the operation moves to the neat step 41,
`fuel consumption by the engine, comprising:
`where some time delay processing is performed, and
`first detecting means for detecting current engine
`then the operation now movesto the step 42.
`speed;
`In this step 42, shift-down display is performed.
`second detecting means for detecting current throttle
`Namelyin this case, the shift down display instruction
`position;
`signal from the microcomputer 5 is applied to the indi-
`third detecting meansfor detecting currentshift posi-
`cator 10 through the I/O port 6 and the shift-down
`tion;
`indication lamp in the indicator 10 is illuminated, thus
`first determining means for determining current en-
`indicating to the driver that speed change operation
`_gine torque based on said currentengine speed and
`' from the current shift position to the one step shifting
`current throttle position in accordance with a first
`downposition SP _; is preferable.
`two-dimensional map of engine speed and throttle
`In this manner, the operations as indicated in each
`position;
`step are repeatedly performed and the assumed fuel
`second determining means for determining current
`consumption rate be+; in the one step shifting up posi-
`fuel consumption rate based on said current engine
`tion and the assumed fuel consumption rate be—1 in the
`speed and determined current engine torque in
`‘one step shifting down position from the current shift
`accordance with a second two-dimensional map of
`position are calculated respectively, and each assumed
`engine speed and engine torque, said second map
`fuel consumption rate is compared with the currentfuel
`including isometric curves representing curves of
`consumption rate b,, respectively. In this case, if the
`equal fuel consumption rates;
`current fuel consumption rate be is better than the as-
`calculating means for calculating driving force of the
`sumed fuel consumption rate be+1 or the assumed fuel
`engine in accordance with current engine speed
`consumption rate b3_1, the indicator 10 is not ener-
`and current engine torque, said calculating means
`gized. However, only when either one of the assumed
`further including:
`fuel consumption rates aboveis better than the current
`first comparing means for comparing said current
`fuel consumption rate be, the corresponding shift-up
`fuel consumption rate obtained by said second
`lamp or shift-down lamp in the indicator 10 is illumi-
`determining means with an assumed one-step-
`nated, thus indicating the necessity of the speed change
`transmission upshifted fuel consumption.rate
`operation. As a result, the driver can actually perform
`determined by one-step-transmission upshifted
`the speed change operations in accordance with the
`engine speed and one-step-transmission upshifted
`indications so that the optimum speed running of the car
`engine torque defined by said second map,
`__ can be carried out with a preferable shift position in the
`second comparing means for comparing said cur-
`“= optimum fuel consumptionrate.
`rent fuel consumption rate obtained by said sec-
`“~~
`In the preferred embodiment according to the present
`ond determining means with an assumed one-
`invention described in the foregoing, the range of each
`step-transmission downshifted fuel consumption
`‘area. indicative of the equal
`fuel consumption rate
`rate determined by one-step-transmission down-
`“curves B has been indicated as 50 g/psh. However, if
`shifted engine speed and one-step-transmission
`the range of each area is defined more narrow or the
`downshifted engine torque defined by said sec-
`distances between the points is interpolated by caicula-
`ond map,
`tion,
`it
`is possible to indicate more accurate speed
`outputting means for outputting a first signal indic-
`change operations.
`ative of one-step upshifting, a second signal in-
`Asstated in the foregoing, in the speed change opera-
`dicative of one-shift downshifting, or a third
`tion and indication system according to the present
`signal indicative of stopping both one-step up-
`invention, the optimum fuel consumptionrate is calcu-
`shifting and downshifting, respectively, when-
`lated from the data corresponding to the number of
`ever said first comparing means determines said
`engine rotation and the throttle valve opening, an as-
`assumed fuel consumption rate of one-step up-
`sumed fuel consumption rate is calculated for generat-
`shifting is less than the currently detected fuel
`ing the same driving poweras that in the current run-
`consumption rate, said second comparing means
`ning conditions in the shift position adjacent to a partic-
`determines said assumed fuel consumption rate
`ular shift position at that time, and the current fuel
`of one-step downshifting is less than the cur-
`consumption rate is compared with the assumed fuel
`rently detected fuel consumption rate, or both
`consumption rate, whereby the optimum shift operation
`values of fuel consumption rate calculated in said
`indications are displayed to the driver.
`first and second comparing meansare detemined
`With this construction, it is possible for a driver to
`greater than the currently detected fuel con-
`run his car in accordance with the indication of the
`sumption rate; and
`speed change operation on an indicator so as to maintain
`‘ representing means for alternatively representing
`the optimum fuel consumption of the automotive vehi-
`whicheverof said three signals are output by said
`cle, thus enabling the economical running of the car to
`outputting means.
`_
`be realized.
`;
`2. A system in claim 1 wherein
`While the invention has been described in its pre-
`said first comparing means comprisesfirst determina-
`ferred embodiments, it is to be understood that various
`tion means for determining whether the current
`changes and modifications may be made within the
`gear position is highest gear or neutral position,
`purview of the appendedclaims without departing from
`and for enabling said comparison ofsaid fuel con-
`
`
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`4,559,599
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`40
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`45
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`50
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`60
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`65
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`4,559,599
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`20
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`25
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`9
`sumption rate if the current shift position is not
`determined to be said highest gear or said neutral
`position; and
`said second comparing means comprises second de-
`termination means for determining whether said
`current shift position is first gear, and for enabling
`said comparison ofsaid fuel consumptionrateif it is
`determinedthe currentshift position is not said first
`gear.
`3. A system in claim 1 wherein
`said first comparing means comprisesfirst calculating -
`means for calculating one-step upshifted assumed
`engine speed obtained from the value of the current
`engine speed, multiplied by a knowngearratio for
`one-step-transmission upshifted, divided by the
`known value for the gear ratio corresponding to
`the current shift position, and for calculating as-
`sumed engine torque obtained from the value of
`current driving force divided by said assumed en-
`gine speed multiplied by a constant;
`said second comparing means comprises second cal-
`culating means for calculating one-step down-
`shifted assumed engine speed obtained from the
`value of the current engine speed, multiplied by a
`known gear ratio for one-step-transmission down-
`shifted, divided by the known value for the gear
`ratio corresponding to the current shift position,
`and for calculating the assumed engine torque ob-
`tained from the value_of current driving force di-
`vided by said assumed engine speed multiplied by a
`constant.
`4. A system as in claim 1, wherein said representing
`means makes an indication to keep the shift position
`unchanged wheneversaid engine speed detected by said
`first detecting means is greater than a predetermined
`value.
`5. A system as in claim 1, further comprising:
`first permitting means for permitting said second
`determining meansto determinesaid fuel consump-
`tion rate wheneverthe value of said engine torque
`determined by said first determining means is
`greater than a predetermined value; and
`second permitting for permitting said second deter-
`mining means to determine said assumed fuel con-
`sumption rate whenever the value of said assumed
`engine torque calculated by said second comparing
`means is greater than said predetermined value.
`6. A system as in claim 1, wherein said representing
`meansrepresents changesin said first, second and third
`signals, indicative of upshifting, downshifting and keep-
`ing shift position unchanged, respectively, after a prede-
`termined time delay.
`7. A method for indicating shift position for a manual
`transmission associated with an internal combustion
`engine so as to maintain optimum fuel consumption by
`the engine, comprising the steps of:
`detecting the current engine speed;
`detecting the current throttle position;
`detecting the current shift position;
`determining current engine torque based onsaid cur-
`rent engine speed and current throttle in accor-
`dance with a first two-dimensional map of engine
`speed and throttle position;
`determining current fuel consumption rate based on
`said current engine speed and determined current
`engine torque in accordance with a second two-di-
`mensional map of engine speed and engine torque
`in accordance with a second two-dimensional map
`
`45
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`60
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`65
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`of engine speed and engine torqu