(12) United States Patent
`Mianzo et al.
`
`I 1111111111111111 11111 lllll lllll 111111111111111 1111111111 1111111111 11111111
`US006557540Bl
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 6,557,540 Bl
`May 6, 2003
`
`(54) METHOD OF CALCULATING A VALVE
`TIMING COMMAND FOR AN ENGINE
`
`(75)
`
`Inventors: Lawrence A. Mianzo, Plymouth, MI
`(US); Brett D. Collins, Ypsilanti, MI
`(US); Ibrahim Haskara, Brownstown,
`MI (US)
`
`4/1998 Schmitz
`5,743,221 A
`5/1998 Schmitz et al.
`5,752,491 A
`6,053,137 A * 4/2000 Trzmiel et al. .......... 123/90.17
`6,196,174 Bl * 3/2001 Wada et al. ............. 123/90.15
`6,330,869 Bl * 12/2001 Yoshiki et al. ........... 123/90.15
`2001/0004884 Al * 6/2001 Tachibana et al. ....... 123/90.15
`2001/0013324 Al * 8/2001 Yoshizawa et al. ...... 123/90.16
`2002/0092488 Al * 7/2002 Aoyama et al. ......... 123/90.16
`
`(73) Assignee: Visteon Global Technologies, Inc.,
`Dearborn, MI (US)
`
`* cited by examiner
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by O days.
`
`(21) Appl. No.: 10/014,286
`
`(22) Filed:
`
`Dec. 11, 2001
`
`Int. Cl.7 ................................................... F0lL 1/34
`(51)
`(52) U.S. Cl. ..................... 123/678; 123/90.15; 701/103
`(58) Field of Search .............................. 123/678, 90.15,
`123/90.19; 701/103
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,700,684 A
`
`10/1987 Pischinger et al.
`
`Primary Examiner-Erick Solis
`(74) Attorney, Agent, or Firm-Brinks Hofer Gilson &
`Liane
`
`(57)
`
`ABSTRACT
`
`A method to calculate valve timing commands for an engine
`with variable valve timing is hereby disclosed. The method
`includes determining a valve feedforward term based on an
`engine performance command and an environmental condi(cid:173)
`tions signal, calculating a valve feedback term based on the
`engine performance command and an engine performance
`feedback, and calculating a valve timing command based on
`the valve feedforward term and the valve feedback term.
`
`16 Claims, 3 Drawing Sheets
`
`16
`
`)
`Obtaining an Engine
`Performance Command
`
`18~
`
`Receiving an
`Environmental
`Conditions Signal
`
`;-v 22
`
`Receiving an Engine
`Performance Feedback
`
`2 0 ---s----
`
`Determining
`a Valve
`Feedforward Term
`
`Calculating a Valve
`Feedback Term
`
`24
`
`i
`
`Calculating a Valve
`Timing Command
`
`i----z__ 26
`
`VW EX1001
`U.S. Patent No. 6,557,540
`
`

`

`U.S. Patent
`
`May 6, 2003
`
`Sheet 1 of 3
`
`US 6,557,540 Bl
`
`28
`
`777777777
`
`777777777
`
`FIGURE 1
`
`

`

`U.S. Patent
`
`May 6, 2003
`
`Sheet 2 of 3
`
`US 6,557,540 Bl
`
`16
`
`)
`Obtaining an Engine
`Performance Command
`
`;v'22
`
`Receiving an Engine
`Performance Feedback
`
`18~
`
`Receiving an
`Environmental
`Conditions Signal
`
`2 0 -s----
`
`Determining
`a Valve
`Feedforward Term
`
`Calculating a Valve
`Feedback Term
`
`n-24
`
`Calculating a Valve
`Timing Command r-L--26
`
`FIGURE 2
`
`

`

`U.S. Patent
`
`May 6, 2003
`
`Sheet 3 of 3
`
`US 6,557,540 Bl
`
`EVC and IVO
`
`FIGURE 3A
`
`~
`
`0 ·-+J ·-r:n
`
`0
`0.,
`
`i::
`0
`+J
`
`rtl ·-P...
`
`IVC
`
`' - - - - - - - - - - - - - - - - - - - - - - time
`FIGURE 3B
`
`

`

`US 6,557,540 Bl
`
`1
`METHOD OF CALCULATING A VALVE
`TIMING COMMAND FOR AN ENGINE
`
`TECHNICAL FIELD
`
`This invention relates generally to calculating commands
`for an engine and, more specifically, to calculating a valve
`timing command for an engine with variable timing valve
`actuators.
`
`BACKGROUND
`
`In gasoline engines of most vehicles, each cylinder of the
`engine cycles through four unique stages. In the first stage,
`an inlet valve opens and a piston draws air and fuel through
`the inlet valve and into the cylinder. The inlet valve closes
`and the piston reverses direction in the second stage to
`compress the air and fuel mixture. In the third stage, a spark
`com busts the mixture, which drives the piston ( and powers
`the vehicle). An exhaust valve opens and the piston once
`again reverses direction, in the fourth stage, to push the
`combusted mixture through the exhaust valve and out of the
`cylinder.
`The controlling of the inlet valve and the exhaust valve of
`each cylinder is a difficult task. The engine speed, which can
`exceed 6,000 rpm in most vehicles, dictates that the opening
`and closing of the inlet valve and the exhaust valve must be
`able to occur up to 50 times per second. In conventional
`engines, cams driven by the engine actuate the inlet valve
`and the exhaust valve. Modern research, however, has
`shown that fuel efficiency and power output of the engine
`may be optimized with an adjustment of the valve timing for
`a particular load on the engine. Some variable valve timing
`engines have been proposed, but the theoretical fuel effi(cid:173)
`ciency and output power of these engines have not yet been
`reached.
`
`BRIEF DESCRIPTION OF THE FIGURES
`
`FIG. 1 is schematic of a vehicle having an engine con- 40
`trolled with the method of the preferred embodiment;
`FIG. 2 is a flowchart of the method of the preferred
`embodiment; and
`FIG. 3 is two timing charts of the valves of an engine.
`
`2
`term. The method performed by the control unit may, of
`course, include other suitable actions before, during, or after
`these principle actions.
`The action of obtaining an engine performance command
`5 16 preferably includes receiving a vehicle performance
`command from a driver. Preferably, the vehicle performance
`command is received from the foot of a driver with the use
`of a conventional pedal 28, as shown in FIG. 1.
`Alternatively, the vehicle performance command could be
`10 received from the driver with the use of any suitable device.
`The action of obtaining an engine performance command
`also preferably includes deriving the engine performance
`command from the vehicle performance command. The
`engine performance command is preferably based on the
`vehicle performance command, but may alternatively be
`15 based on additional suitable factors, such as a traction
`control signal or a cruise control signal. The engine perfor(cid:173)
`mance command is preferably a desired engine torque and,
`for this reason, the engine performance command may be
`thought of as an engine torque command. The engine
`20 performance command, however, may alternatively be
`another suitable variable, such as a desired engine accelera(cid:173)
`tion.
`The action of receiving an environmental conditions
`signal 18 preferably includes receiving an environmental
`25 conditions signal from an environmental sensor 30 in the
`vehicle. The environmental sensor 30 preferably senses the
`ambient temperature outside the vehicle and communicates
`this data to the control unit 10, which uses the data to
`determine the valve feedforward term. Other information,
`30 such as the ambient pressure, may be useful in the determi(cid:173)
`nation of the valve feedforward term. For this reason, the
`environmental sensor 30 may alternatively sense other suit(cid:173)
`able information. The environmental sensor 30 is preferably
`a conventional environmental sensor, but may alternatively
`35 be any suitable device.
`Similarly, the action of receiving an engine performance
`feedback 22 preferably includes receiving the engine per(cid:173)
`formance feedback from an engine sensor 32 in the vehicle.
`The engine sensor 32 preferably senses the engine speed and
`communicates this data to the control unit 10, which uses the
`data to determine the valve feedforward term and the valve
`feedback term. Other engine measurables, such as engine
`torque data, may be useful in the determination of the terms.
`For this reason, the engine sensor 32 may alternatively sense
`45 other suitable information. The engine sensor 32 is prefer(cid:173)
`ably a conventional engine sensor, but may alternatively be
`any suitable sensor.
`The action of determining a valve feedforward term 20
`preferably includes determining the valve feedforward term
`based on the engine torque command, the ambient tempera(cid:173)
`ture data, and the engine speed data. The determination,
`however, may be based on other suitable factors, such as
`engine torque data, air-fuel ratio data, engine combustion
`stability data, or ambient pressure data. The control unit 10
`55 preferably includes a look-up table, which has been opti(cid:173)
`mized for fuel efficiency, power output, and engine emis(cid:173)
`sions based on various engine torque commands, various
`ambient temperature data, and various engine speed data ( or
`engine torque data). The control unit 10 may alternatively be
`60 programmed to perform a real-time optimization of the fuel
`efficiency, power output, and engine emission ( or any other
`suitable measurement) based on the engine torque
`command, the ambient temperature data, and the engine
`speed data ( or any other suitable commands and
`65 measurables).
`The action of calculating the valve feedback term 24
`preferably includes comparing the engine performance com-
`
`DESCRIPTION OF THE PREFERRED
`METHODS
`
`The following description of the two preferred method of
`the invention is not intended to limit the invention to these 50
`preferred methods, but rather to enable any person skilled in
`the art of variable valve timing control to make and use this
`invention.
`As shown in FIG. 1, the preferred method of the invention
`has been specifically created to be performed by a control
`unit 10 to calculate valve timing commands for an engine 12
`with electromagnetic valve actuators 14. The method,
`however, may be performed by any suitable device to
`calculate valve timing commands for any suitable engine
`with any suitable variable timing valves.
`As shown in FIG. 2, the preferred method of the invention
`has six principle actions: obtaining an engine performance
`command 16; receiving an environmental conditions signal
`18; determining a valve feedforward term 20; receiving an
`engine performance feedback 22; calculating a valve feed(cid:173)
`back term 24; and calculating a valve timing command 26
`based on the valve feedforward term and the valve feedback
`
`

`

`US 6,557,540 Bl
`
`3
`mand and the engine performance feedback. By the defini(cid:173)
`tion of the term, the valve feedback term functions to
`compare the input with the output and to calculate a cor(cid:173)
`rection term based on the difference, if any. The comparison
`and the calculation are preferably accomplished by the 5
`control unit 10, but may alternatively be accomplished by a
`suitable separate device.
`As shown in FIG. 3A, the position of the piston in the
`cylinder can be traced as a sinusoidal wave over a time
`period. The events of the opening of the exhaust valve 10
`("EYO"), the closing of the exhaust valve ("EYC"), the
`opening of the inlet valve ("IYO"), and the closing of the
`inlet valve ("IYC") can be placed on this sinusoidal wave.
`As shown in FIG. 3B, the events of the EYO, the EYC, the
`IYO, and the IYC may be shifted within the time period 15
`(note that the shift in the EYC and the IYO preferably mirror
`each another, but may alternatively be separately
`controlled). The adjustment of the timing of the EYO, the
`EYC/IYO, and the IYC when used partially, separately, or
`together may provide the desired fuel efficiency, power 20
`output, and emissions from the engine 12 of the vehicle. The
`action of calculating a valve timing command 26 preferably
`includes calculating an EYO command, an EYC/IYO
`command, and an IYC command. The control unit 10, of
`course, may alternatively include other suitable parameters 25
`for the control of the variable timing valves.
`The second preferred method of the invention includes the
`principle actions of the first preferred method and the
`additional principle action of receiving fuel conversion data
`and engine emissions data. These preferably include receiv- 30
`ing the fuel conversion data and engine emissions data from
`suitable emission sensors (not shown) in the cylinder or the
`exhaust port of the engine 12. The emission sensors prefer(cid:173)
`ably sense the amount of NOx in the exhaust and commu(cid:173)
`nicates this data to the control unit 10. The control unit 10
`preferably uses this information to modify the output value
`from the look-up table, but may alternatively use this
`information to continually adjust the values in the look-up
`table. The control unit 10 may alternatively use this infor(cid:173)
`mation as another factor in the determination of the valve 40
`feedback term. The emission sensors are preferably conven(cid:173)
`tional emission sensors, but may alternatively be any suit(cid:173)
`able sensor.
`As any person skilled in the art of variable valve engine
`control will recognize from the previous detailed description
`and from the figures and claims, modifications and changes
`can be made to the preferred methods without departing
`from the scope of this invention defined in the following
`claims.
`We claim:
`1. A method for calculating a valve timing command for
`an engine of a vehicle, comprising:
`obtaining an engine performance command;
`receiving an environmental conditions signal;
`determining a valve feedforward term based on the engine
`performance command and the environmental condi(cid:173)
`tions signal;
`
`4
`receiving an engine performance feedback;
`calculating a valve feedback term based on the engine
`performance command and the engine performance
`feedback; and
`calculating a valve timing command based on the valve
`feedforward term and the valve feedback term.
`2. The method of claim 1 wherein said obtaining an
`engine performance command includes receiving a vehicle
`performance command from a driver of the vehicle and
`deriving the engine performance command based on the
`vehicle performance command.
`3. The method of claim 1 wherein said receiving an
`environmental conditions signal includes receiving ambient
`temperature data.
`4. The method of claim 3 wherein said determining a
`valve feedforward term includes determining the valve
`feedforward term based on the ambient temperature data.
`5. The method of claim 4 wherein said determining a
`valve feedforward term includes determining the valve
`feedforward term based on the engine performance feed(cid:173)
`back.
`6. The method of claim 5 wherein said determining a
`valve feedforward term includes referencing a look-up table
`with the engine performance command, the ambient
`temperature, and the engine performance feedback.
`7. The method of claim 1 wherein said receiving an engine
`performance feedback includes receiving engine speed data.
`8. The method of claim 1 wherein said obtaining an
`engine performance command includes obtaining an engine
`torque command; and wherein receiving an engine perfor(cid:173)
`mance feedback includes receiving engine torque data.
`9. The method of claim 8 wherein calculating a valve
`35 feedback term includes calculating a valve feedback term
`based on the engine torque command and the engine torque
`data.
`10. The method of claim 1 wherein said calculating a
`valve timing command includes calculating an EYO
`command, an EYC/IYO command, and an IYC command.
`11. The method of claim 1 further comprising receiving
`fuel conversion data.
`12. The method of claim 11 wherein said determining a
`valve feedforward term includes determining a valve feed-
`45 forward term based on the fuel conversion data.
`13. The method of claim 11 wherein said calculating a
`valve feedback term includes calculating a valve feedback
`term based on the fuel conversion data.
`14. The method of claim 1 further comprising receiving
`50 engine emissions data.
`15. The method of claim 14 wherein said determining a
`valve feedforward term includes determining a valve feed(cid:173)
`forward term based on the engine emissions data.
`16. The method of claim 11 wherein said calculating a
`55 valve feedback term includes calculating a valve feedback
`term based on the engine emissions data.
`
`* * * * *
`
`