GB2225655A - Idle speed control system - Google Patents

Idle speed control system Download PDF

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Publication number
GB2225655A
GB2225655A GB8926438A GB8926438A GB2225655A GB 2225655 A GB2225655 A GB 2225655A GB 8926438 A GB8926438 A GB 8926438A GB 8926438 A GB8926438 A GB 8926438A GB 2225655 A GB2225655 A GB 2225655A
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GB
United Kingdom
Prior art keywords
nominal
value
cycle
duty
signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8926438A
Other versions
GB8926438D0 (en
GB2225655B (en
Inventor
Marco Calfus
Carlo Conticelli
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Marelli Europe SpA
Original Assignee
Marelli Autronica SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Marelli Autronica SpA filed Critical Marelli Autronica SpA
Publication of GB8926438D0 publication Critical patent/GB8926438D0/en
Publication of GB2225655A publication Critical patent/GB2225655A/en
Application granted granted Critical
Publication of GB2225655B publication Critical patent/GB2225655B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D31/00—Use of speed-sensing governors to control combustion engines, not otherwise provided for
    • F02D31/001—Electric control of rotation speed
    • F02D31/002—Electric control of rotation speed controlling air supply
    • F02D31/003—Electric control of rotation speed controlling air supply for idle speed control
    • F02D31/005—Electric control of rotation speed controlling air supply for idle speed control by controlling a throttle by-pass
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D11/00—Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated
    • F02D11/06—Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated characterised by non-mechanical control linkages, e.g. fluid control linkages or by control linkages with power drive or assistance
    • F02D11/10—Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated characterised by non-mechanical control linkages, e.g. fluid control linkages or by control linkages with power drive or assistance of the electric type
    • F02D2011/101—Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated characterised by non-mechanical control linkages, e.g. fluid control linkages or by control linkages with power drive or assistance of the electric type characterised by the means for actuating the throttles
    • F02D2011/102—Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated characterised by non-mechanical control linkages, e.g. fluid control linkages or by control linkages with power drive or assistance of the electric type characterised by the means for actuating the throttles at least one throttle being moved only by an electric actuator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2024—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit the control switching a load after time-on and time-off pulses
    • F02D2041/2027—Control of the current by pulse width modulation or duty cycle control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2058—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit using information of the actual current value
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2065—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit the control being related to the coil temperature

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Magnetically Actuated Valves (AREA)

Description

I.
Title: A DEVICE FOR THE CLOSED-LOOP CONTROL OF THE IDLING SPEED OF AN INTERNAL COMBUSTION ENGINE The present invention relates to a device for the loop control of the idling speed of an internal combustion engine to which air is supplied, in operation, through a duct provided with a throttle valve.
The device according to the present invention is characterised in that it comprises in combination: a solenoid valve for adjusting the quantity of air supplied to the engine, arranged in a by-pass duct of a throttle valve and provided with an excitation coil; an electronic switch in series with the coil, between the two poles of a direct-voltage supply, a signal generator for applying a square-wave signal with a variable duty cycle to a control input for.switching the switch,,. sensor means for providing electrical signals indicative of operating conditions of the engine, including the rate of revolution and the temperature of the engine, monitoring means for monitoring the current flowing in the coil of the solenoid valve, and an electronic control unit for controlling the duty-cycle of the signal emitted by the generator in a predetermined manner in dependence on the signals provided by the sensor means and by the monitoring means, the unit being arranged to calculate cyclically, in a predetermined manner and in dependence on the values assumed by the parameters monitored by the sensor means, a nominal value of the duty cycle of the signal applied to the electronic switch, the nominal value being predetermined with reference to preset values of the temperature at the solenoid valve and of the voltage delivered by the supply, and 2 then correct the nominal duty-cycle value in dependence on the difference between the detected intensity of the current f lowing in the coil of the solenoid valve and the nominal current intensity which corresponds to the nominal duty-cycle value.
Further characteristics and advantages of the present invention will become clear from the detailed description which follows with reference to the appended drawings, provided by way of non-limiting example, in which:
Figure 1 is a diagram of a control device according to the invention, Figure 2 is a detailed electrical diagram which shows the structure of a processing circuit included in the device of Figure 1, Figure 3 is a series of f our graphs which show the traces of four signals generated in the device of Figure 1 in operation, as functions of the time shown on the abscissa, and Figure 4 is a diagram showing the type of closed-loop control achieved by the device according to the invention.
With reference to Figure 1, an air-intake duct of an internal combustion engine with spark ignition (not illustrated) is indicated A. The air coming from a filter travels through this duct towards the engine in the direction of the arrows shown.
The duct A is provided with a butterfly valve,indicated 3 B. Two by-pass ducts between the regions upstream and downstream of the butterfly valve B are indicated C and D.
In known manner, an adjustment screw S is situated in the by-pass duct C.
The flow of air through the by-pass duct D is controlled by a solenoid valve, generally indicated E, which includes an excitation coil, indicated W.
An npn-type transistor is indicated 1 and its collector-emitter path is arranged in series with the coil W, between the two poles of a direct voltage supply V.
A diode 2 is connected in the manner illustrated, in parallel with the coil W.
A resistor 3 is connected in series with the collector-emitter path of the transistor 1, and in particular between the emitter of the transistor and earth. In operation, when the transistor 1 is made conductive, a current f lows in the coil W and in the resistor 3. In this situation,the potential difference across the resistor is proportional to the current which is flowing through the coil. This potential difference is applied as an input signal to a processing circuit, generally indicated 4 in Figure 1 and shown in greater detail in Figure 2.
The analog signal output by the processing circuit 4 is converted into corresponding digital signals by an 4 analog/digital converter 5. The digital signals are transmitted to an electronic control unit 6 produced, for example, with the use of a microprocessor.
Sensors 7-N are connected to the control unit 6 and provide it with electrical signals indicative of operating parameters of the engine, including the rate of revolution of the engine, the engine temperature, etc.
The unit 6 controls the operation of a signal generator 8 which in turn applies to the base of the transistor 1 a switching signal which has a square-wave trace with a duty cycle which is controlled by the unit 6.
As shown in Figure 2, the processing circuit 4 includes a passive integrator 9 produced, in known manner, with a resistor 10 and a capacitor 11. The output of the integrator is connected to the input of an amplifier stage 12 which, in the example illustrated, is produced with the use of an operational amplifier 13.
The amplifier stage 12 is connected to the input of a dynamic rangeexpander stage 14, also of known type, produced,in the example illustrated,with the use of two transistors 15 and 16. The output of the dynamic range-expander 14 is connected to the input of the analog-digital converter 5.
The function of the dynamic range expander. circuit is to enable the maximum possible resolution to be achieved in the conversion carried out by the converter 5. In fact, if the operational amplifier 13 outputs a maximum voltage of approximately 3.5 V (when supplied with a supply voltage of 5V) the circuit 14 makes the :1 signal vary between 0 and the reference voltage of the converter 5 and therefore, for example, to vary from 0 to 5V, thus enabling maximum possible resolution to be achieved.
Figure 3 shows example traces of the following signals:
V C: the voltage applied by the circuit 8 to the base of the transistor 1: this is a square-wave signal whose duty cycle, as stated above, is controlled by the unit 6; I w: the intensity of the current which correspondingly flows in the excitation coil W of the solenoid valve E; V R: the voltage across the resistor 3; the trace of this voltage corresponds substantially to that of I w when the signal V C is "on", but assumes a zero value when the transistor 1 is switched off (in this case the current I w flows in the loop formed by the coil W and the associated recirculating diode 2; V s: the voltage output by the integrator 9: the trace of this signal corresponds substantially to the trace of the current I W In operation, the unit 6 sets a certain value for the duty cycle of the signal generated by the circuit 8 and applied to the base of the transistor 1, on the basis of the information coming from the sensors 7-N and from the analog/digital converter 5. In fact, by modulating the duty cycle of the signal provided by the generator circuit 8, the unit 6 causes a corresponding variation in the average current flowing in the coil W of the solenoid valve E and therefore in the flow of air admitted through the by-pass duct D.
6 However, the current f lowing in the coil W is not a function soley of the duty cycle of the signal output by the generator circuit 8. In fact, for a given duty cycle, the current in W can vary as a result of the variation of the supply voltage V and/or as a result of temperature variation, which can cause a variation in the resistance of W.
For this reason, the unit 6 is arranged to calculate cyclically, in a predetermined manner, in dependence on the values assumed by the parameters monitored by the sensors 7-N, a nominal value of the duty cycle of the signal applied to the base of the transistor 1, box 50 in Figure 4. This nominal value is predetermined with reference to preset values of the temperature of the solenoid valve E, particularly of its coil W, and of the voltage delivered by the supply V. These preset values may, for example, be 40 0 C for the temperature of the coil W and 14V for the voltage delivered by the supply V.
A quite precise value of the current 1 W in the coil W, that is, a quite definite nominal intensity, corresponds to the nominal value of the duty cycle of the signal V C under the reference conditions of the temperature and the supply voltage. When the temperature of W and the voltage of V vary, the actual current flowing in W will differ from the nominal intensity. Consequently, for each cycle, the unit 6 "reads"r that is acquires, the value of the voltage across the resistor 3, which is indicative of the effective or actual current intensity in W (box 52 of Figure 4). In ef fect, as stated above, the unit 6 acquires the value of the signal V R at the output of the integrator circuit 9 of the processing circuit 4.
L 7 The signal V R thus acquired is compared (box 53) with a nominal value V Rnom (box 54) which is generated in the manner which will be described below. On the basis of the difference between these values, the unit 6 calculates a correction factor for the duty cycle (box 55) with a suitable positive or negative sign, and this is added algebraically (box 56) to the nominal value computed on the basis of the detected values of the parameters monitored. The effective duty cycle (box 57) to be set for the signal output by the generator circuit 8 to the base of the resistor 1 is thus defined.
The definition of the nominal voltage value V Rnom takes place in the following manner. A table of values of V Rnom arranged, for example, in lines and columns is stored in memory circuits of the unit 6. The columns can be addressed on the basis of ranges of values of the nominal dutycycle calculated on the basis of the signals provided by the sensors 7-N. The lines can be addressed, however, on the basis of ranges of values of the effective duty cycle, that is, of the duty cycle obtained after the correction carried out in box 56.
The unit 6 can thus determine the correct duty cycle value in any situation, even with variations in the supply voltage V and/or the temperature of the coil W.
The unit 6 is conveniently arranged to provide the analog/digital converter 5 with a conversion command pulse substantially at the moment when the transistor is switched off, that is, with reference to Figure 3, each time the signal V is made to switch from the "high" level to the "low" level. The sampled value of the signal V S thus corresponds substantially to the maximum reached.
8

Claims (4)

1. A device for the closed-loop control of the idling speed of an internal combustion engine to which air is supplied, in operation, through a duct, provided with a throttle valve, characterised in that it comprises in combination a solenoid valve for adjusting the quantity of air supplied to the engine, arranged in a by-pass duct of a throttle valve and provided with an excitation coil 01 an electronic switch in series with the coil between the two poles of a direct voltage supply I a signal generator for applying a square-wave signal with a variable duty cycle to a control innut for switchina the s itch sensor means F for providing electrical signals indicative of the operating conditions of the engine, incuding the rate of revoution and the temperature of the engine, monitoring means for monitoring the current flowing in the coil of the solenoid valve, and an electronic control unit for controlling the duty-cycle of the signal emitted by the generator in a predetermined manner in dependence on the signals provided by the sensor means and by the monitoring means the unit being arranged to calculate cyclically, in a predetermined manner and in dependence on the values assumed by the parameters monitored by the sensor means a nominal value of the duty cycle of the signal applied to the electronic switch the nominal value being predetermined with reference to preset values of the temperature at the solenoid valve c 11 9 1 and of the voltage delivered by the supply, and then correct the nominal duty-cycle value in dependence on the difference between the detected intensity of the current flowing in the coil of the solenoid valve and the nominal current intensity which corresponds to the nominal duty-cycle value.
2. A device according to Claim 1, characterised in that the monitoring means are arrangedto provide a voltage signal which is proportional to the actual current flowing in the solenoid valve and in that the unit jI is arranged to - acquire the voltage value provided by the monitoring means 1 - generate a nominal voltage value in dependence on the nominal duty-cycle value calculated, - generate a correction factor for the duty cycle whose sign and magnitude depend on the difference between the nominal voltage value generated and the voltage value acquired, and - apply to the generator signals indicative of the effective duty cycle which corresponds to the value obtained by the addition of the correction factor to the nominal duty cycle value
3. A device according to Claim 2, characterised in that the electronic unit is arranged to generate the nominal voltage value for each cycle according to a predetermined function of the calculated nominal duty-cycle value, and of the effective duty-cycle value set for the signal generator
4. A device according to any one of the preceding claims, in which the monitoring means comprise a resistor arranged in series with the switch 81 1 characterised in that between the resistor and the electronic control unit are interposed an integrator whose input is connected to the resistor., an amplif ier integrator and an analog/digital converter output of the amplifier connected to the outr)ut of the connected to the A device according to Claim 4, characterised in that a dynamic range expander circuit is interposed between the amplifier and the analog/digital converter 6. A device according to Claim 4 or Claim 5, characterised in that the analog/digital converter is piloted by the electronic control unit which is arranged to provide the i converter with a conversion command pulse substantially in correspondence with each switching-off of the current through the switch A device for the closed loop control of the idling speed of an internal combustion engine to which air is supplied, in operation, through a duct provided with a throttle valve substantially as hereinbefore described with reference to the accompanying drawings Published1990 a:, The Patent O.1'ice.S,ateHciuse 66 7. High F-ur.ne: c-- pieci,.a-'.,eo"-a,ne-froinT17.eF-aentC)f,',Ce Sales Branch. st ma,7,. Orp-rg"--,-. Ken, BEL5 3EL Prin-ej bv T'eCh. c:-- ez ---S Man: c.' k: Ken. Czr. ' E- i
GB8926438A 1988-11-30 1989-11-22 A device for the closed-loop control of the idling speed of an internal combustion engine Expired - Fee Related GB2225655B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT68073/88A IT1223958B (en) 1988-11-30 1988-11-30 CLOSED RING CONTROL DEVICE FOR IDLE ROTATION SPEED OF AN INTERNAL COMBUSTION ENGINE

Publications (3)

Publication Number Publication Date
GB8926438D0 GB8926438D0 (en) 1990-01-10
GB2225655A true GB2225655A (en) 1990-06-06
GB2225655B GB2225655B (en) 1993-01-27

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GB8926438A Expired - Fee Related GB2225655B (en) 1988-11-30 1989-11-22 A device for the closed-loop control of the idling speed of an internal combustion engine

Country Status (4)

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DE (1) DE3939455A1 (en)
FR (1) FR2639680A1 (en)
GB (1) GB2225655B (en)
IT (1) IT1223958B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996032580A1 (en) * 1995-04-12 1996-10-17 Robert Bosch Gmbh Process and device for controlling an electromagnetic consumer

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2739937B1 (en) * 1995-10-13 1997-12-05 Siemens Automotive Sa METHOD FOR DETERMINING THE AVERAGE CURRENT FLOWING IN AN INDUCTIVE LOAD
JPH1039902A (en) * 1996-07-19 1998-02-13 Komatsu Ltd Current controller
JP2003161235A (en) * 2001-11-26 2003-06-06 Denso Corp Intake device for internal combustion engine
JP6953829B2 (en) * 2017-06-23 2021-10-27 株式会社ノーリツ Combustion device
CN110960818B (en) * 2019-11-05 2020-12-01 中国地质大学（北京） Quick fire extinguishing device for front cabin of automobile and method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0223430A2 (en) * 1985-10-21 1987-05-27 Honda Giken Kogyo Kabushiki Kaisha Method for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine
EP0223426A2 (en) * 1985-10-21 1987-05-27 Honda Giken Kogyo Kabushiki Kaisha Method and apparatus for controlling the solenoid current of a solenoid valve which controls an internal combustion engine
EP0225031A2 (en) * 1985-10-21 1987-06-10 Honda Giken Kogyo Kabushiki Kaisha Method and apparatus for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine
GB2186714A (en) * 1986-02-13 1987-08-19 Honda Motor Co Ltd Air supply control arrangement for an internal-combustion engine
EP0270102A2 (en) * 1986-12-03 1988-06-08 Fuji Jukogyo Kabushiki Kaisha System for controlling idle speed of an engine

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0733797B2 (en) * 1983-05-06 1995-04-12 トヨタ自動車株式会社 Idle speed control method
JPS59226249A (en) * 1983-06-06 1984-12-19 Mazda Motor Corp Apparatus for controlling idling speed of engine
JPS6022034A (en) * 1983-07-15 1985-02-04 Toyota Motor Corp Engine-speed controlling method for internal-combustion engine
JPS6153437A (en) * 1984-08-23 1986-03-17 Mitsubishi Electric Corp Control device for idling rpm in internal-combustion engine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0223430A2 (en) * 1985-10-21 1987-05-27 Honda Giken Kogyo Kabushiki Kaisha Method for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine
EP0223426A2 (en) * 1985-10-21 1987-05-27 Honda Giken Kogyo Kabushiki Kaisha Method and apparatus for controlling the solenoid current of a solenoid valve which controls an internal combustion engine
EP0225031A2 (en) * 1985-10-21 1987-06-10 Honda Giken Kogyo Kabushiki Kaisha Method and apparatus for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine
GB2186714A (en) * 1986-02-13 1987-08-19 Honda Motor Co Ltd Air supply control arrangement for an internal-combustion engine
EP0270102A2 (en) * 1986-12-03 1988-06-08 Fuji Jukogyo Kabushiki Kaisha System for controlling idle speed of an engine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996032580A1 (en) * 1995-04-12 1996-10-17 Robert Bosch Gmbh Process and device for controlling an electromagnetic consumer
CN1071406C (en) * 1995-04-12 2001-09-19 罗伯特·博施有限公司 Process and device for controlling electromagnetic consumer

Also Published As

Publication number Publication date
IT8868073A0 (en) 1988-11-30
GB8926438D0 (en) 1990-01-10
IT1223958B (en) 1990-09-29
DE3939455A1 (en) 1990-05-31
GB2225655B (en) 1993-01-27
FR2639680A1 (en) 1990-06-01

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PCNP Patent ceased through non-payment of renewal fee

Effective date: 19981122