JP2000221070A - Method and device for controlling drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate and control utilizable information on the tank capacity and/or running distance by setting a control quantity as a function of values indicating the tank capacity, the liquid level in the tank, and the remaining running distance of a vehicle by residual fuel. SOLUTION: A microcomputer 14 reads the signal of a level gauge 22, and obtains the scale for an attainable remaining running distance by the capacity in a tank at that time. When the capacity in tank or the remaining running distance becomes below a first threshold, a tank low level lamp 56 is lighted. Further when it becomes below a second threshold lower than the first one, the tank two level lamp 56 is changed into frickering operation. According to this, when an internal combustion engine is provided with a turbocharger 42, for controlling to optimize the efficiency, reduction of intake pressure, lock of over boost function, efficiency optimizing adjustment of the intake pressure and a throttle valve 38 opening, and the like are performed. In the case without a turbocharger, limiting of engine charging quantity by adjusting the throttle valve 38 or the other adjustment adjusting the charging quantity is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling an automobile drive unit.

[0002]

BACKGROUND OF THE INVENTION On-board computers are often used for controlling vehicle drive units, and the computer directs the driver with a great deal of information about the operating variables of the drive unit, the vehicle, and / or its associated components. For example, in a state-of-the-art vehicle, the current tank capacity (tank liquid level), instantaneous fuel consumption, average fuel consumption, remaining mileage, etc. are measured or calculated, and the driver is instructed via the instruction means. Is done. Such an on-board computer is, for example, Knut Gebhar
dt and Harald Scheufler,
"A New Generation of On-board Computers in Automobiles", Automotive Technology Magazine (ATZ), Vol. 85 (1983), February, 8
It is known from the literature on pages 1-84. In the known method, even if a very low remaining mileage or a very low tank volume is detected, the conclusion from the indicated information is left to the driver only.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Alternatively, it is an object of the invention to further evaluate the available information on the mileage.

[0004]

The object of the present invention is to provide a method of controlling a drive unit, wherein at least one control variable for controlling the drive unit is determined as a function of an operating variable, wherein the control variable is the tank capacity, This is achieved by the control method of the drive unit according to the present invention, which is a function of a value indicating a remaining level of the vehicle due to the liquid level or the remaining fuel.

[0005] The above object is also achieved in a drive unit control device comprising a control unit for determining at least one control variable for controlling the drive unit as a function of at least one operating variable, wherein the control unit comprises: This is achieved by a control device for a drive unit according to the invention, characterized in that it determines values representing the quantity, the tank level or the remaining mileage and determines the control quantity as a function of these values.

By controlling the drive unit as a function of the tank capacity and / or the remaining mileage, these available information are further evaluated and especially in critical driving situations where the tank capacity and the remaining mileage are low. Drivers are effectively supported. When the tank capacity or the remaining mileage is small, an optimum utilization of the remaining fuel and an increase in the remaining mileage are achieved. Driver engagement, which can adversely affect fuel consumption and remaining mileage, is subsequently reduced.

[0007] It is particularly advantageous if the control of the drive unit consisting of the internal combustion engine and / or the automatic transmission is performed in such a way as to optimize the efficiency as much as possible, in which case the power and the riding comfort are sacrificed. Priority is given to the optimal use of fuel still available for driving.

It is particularly advantageous that the control engagement of the drive unit as a function of the tank capacity and / or the remaining mileage involves a flashing operation of the tank low lamp in the vehicle's indicating instrument. This informs the driver of the limit situation and, if the drive unit, the changed control.

The vehicle travel distance is increased only when the tank capacity (tank liquid level) and / or the remaining travel distance is lower than a predetermined threshold value that is below the threshold value for operating the tank low lamp. It is particularly advantageous for the control to take place.

[0010] For the efficiency optimization control of the drive unit,
Efficiency optimizing adjustment of supply pressure and throttle valve opening, which reduces the supply pressure, locks the over-boost function, and the driver's desire for driving is met by the minimum possible supply pressure at the maximum possible throttle opening. It is particularly advantageous. It is particularly advantageous that these measures are taken together.

Another advantageous engagement of the internal combustion engine is the restriction of the engine charge by means of a throttle valve engagement or other regulating engagement which affects the charge in a supercharged engine. Furthermore, it is advantageous to switch to lean running operation and to interrupt control at λ = 1.

Another advantageous engagement measure is to lock the kick down function and / or to prioritize efficiency.
It is in the selection of the traveling speed or the gear speed in the automatic transmission control. Another advantage is that during idle operation without actuation of the clutch pedal, for example, after a short waiting time, an automatic engine stop function is activated, which shuts off the engine.

[0013] All these measures advantageously maximize the use of the vehicle in residual driving and protect the structural components, in particular the catalyst.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIG. 1 shows a control unit 10 including at least one input circuit 12, microcomputer 14 and output circuit 16. These components are connected by a communication system 18 for data exchange with each other. The input circuit 12 is supplied via input lines with signals which are evaluated for control and represent operating variables of the drive unit and / or the vehicle. The first input line 20 supplies a signal, generated from a liquid level gauge 22 in the fuel tank 24 of the vehicle, representing the respective liquid level or tank capacity. In addition, the engine speed, supply air mass flow rate, accelerator pedal position, oxygen content in the exhaust gas of the internal combustion engine, supply in the engine with turbocharger, Signals representing other operating variables, such as air pressure, operating signals for the clutch pedal, etc., are provided. The supplied values are evaluated and converted into control signals in a microcomputer 14 within a program for controlling a drive unit of the vehicle, which is executed there.
With this control signal, the microcomputer 14 outputs a control variable via the output circuit 16 to the drive unit, in particular to the internal combustion engine and / or the automatic transmission. In FIG. 1, the electrically operated throttle valve 38 operated via an output line 40, the turbocharger 42 operated via an output line 44, and the automatic transmission 46 operated via an output line 48 as adjusting elements. , And the symbolized output line 52
An adjusting element 50 for adjusting the fuel supply and / or the ignition angle, which is actuated via, is shown. further,
The low tank lamp 56 is operated via the output line 54.

The microcomputer 14 has a program for controlling the internal combustion engine and / or the automatic transmission as a function of the signals read or the values derived therefrom by corresponding adjustment of the available control elements. Such a control is known from the prior art. In addition, the microcomputer 14 reads the signal of the level gauge 22 and forms from this a measure for the current tank capacity, or for the remaining mileage achievable with the existing tank capacity. Examples for the determination of the tank capacity and the calculation of the remaining mileage are known from the prior art mentioned at the outset. When the tank capacity or the remaining mileage falls below a predetermined first threshold, the tank low lamp 5
6 is operated. This function corresponds to the operation of the low tank lamp when the tank capacity is low, which is common in today's vehicles. In addition, a second threshold value is provided for the tank capacity, the tank level or the remaining mileage, which is smaller than the first threshold value, and which falls below this threshold value, Is switched to a different operation, for example, a blinking operation. In order to extend the mileage, in addition to this changed operation of the tank low ramp, means are provided for controlling the drive unit to optimize the efficiency as much as possible. In this case, ride quality and power are sacrificed.

When the internal combustion engine has a turbocharger, the supply pressure is reduced, the over-boost function is locked, and / or the efficiency of the supply pressure and the throttle valve opening is optimized for the efficiency optimization control of the internal combustion engine. Modification adjustment is performed. In the latter case, the driver's wishes (for example with respect to the torque or power of the internal combustion engine) are met by the maximum possible throttle opening at the minimum possible supply pressure and, accordingly, the efficiency of the internal combustion engine is improved. Efforts are made to drive as they do.

In an internal combustion engine without a turbocharger, as well as in a turbocharged internal combustion engine, in addition to or in lieu of the above-mentioned measures, the restriction of the engine charge by means of throttle control or the charge is defined. Other adjusting engagements to adjust are provided. For this purpose, a maximum position of the throttle flap is provided, which limits the intake air mass flow and thus reduces the fuel consumption or avoids excessive consumption of fuel by setting the corresponding driver. Limiting the maximum engine speed, limiting the maximum torque, limiting the maximum running speed, or limiting the maximum acceleration will achieve the same result.

Other measures which are used in addition to or as an alternative to the above measures are shutting off the λ control and switching to lean operation. When a tank level range where the fuel in the tank is extremely low is detected, misfiring is presumed due to the short-time air suction, which makes it impossible to reliably maintain the exhaust gas composition. The shut-off of the λ control and the switch to lean operation are, in this operating range, on the one hand for reasons of catalyst protection (cold exhaust gas due to excess air) and on the other hand due to the improved efficiency for increasing the mileage. This is justified if a slightly higher NOx value is sacrificed in this case. In addition, the driver is informed of this operating condition by a flashing tank low lamp.

In vehicles with automatic transmissions, in addition to or instead of the measures described above, the kick-down function is locked, and the drive or gear stage is selected with a priority on efficiency only. The switching characteristic curve is determined in such a manner that the gear is switched to another gear only when the operation of the internal combustion engine is disadvantageous in terms of fuel consumption or efficiency.

In an engine having an automatic shut-down system in idle operation, instead of or in addition to the above measures, in idle operation in which the clutch pedal is not operated, the engine is automatically shut down after a short waiting time. It may be designed. Correspondingly, the engine is automatically restarted the next time the clutch is operated.

All of these measures, individually or in any combination, serve to increase the remaining mileage and leave the vehicle stationary due to lack of fuel in the driver's unfavorable driving manner. Effectively delay.

In a preferred embodiment, the above method is implemented as a microcomputer program of the control unit. An example of such a program is shown in the flowchart of FIG. This flowchart is executed at predetermined time intervals when the supply voltage is turned on.

After the start of the program part, in step 100 a value representing the tank level T and / or a value R representing the remaining mileage is read. In a subsequent step 102, at least one of these values is compared to a second threshold. If this value exceeds a second threshold, the corresponding value is compared to a first threshold greater than the second threshold (step 1).
04). If the corresponding value is below the first threshold, that is, if the corresponding value lies halfway between the first and second threshold, the tank low lamp is operated continuously. (Step 106). Then, as in the case of a negative answer in step 104, in which the checked value is above the first threshold value, the operation of the drive unit is carried out without restriction and within normal operation. The program is then terminated and repeated after the next time interval.

If step 102 provides that the tested value is less than the second threshold, step 108 causes the lamp to flash. Thereafter, in step 110, a transition is made to the drive unit efficiency optimization control or fuel consumption optimization control using at least one of the measures described above. After step 110, the program is terminated and repeated after the next time interval. The control for optimizing the efficiency of the drive unit or the control for optimizing the fuel consumption takes place as long as the value to be checked, ie the tank level or the mileage, is smaller than a second threshold value. After the tank is refueled, normal operation is switched again.

The program shown in FIG. 2 is executed in the engine control unit, and the low tank lamp is also operated by the engine control unit. In other embodiments,
Monitored values (tank capacity, remaining mileage)
When is below the threshold, in addition to or instead of the above measures, the following measures are introduced. The coupling of the air-conditioning compressor is released, so that the air-conditioning compressor no longer loads the engine. Electrical heating, such as refrigerant heating in most diesel engines, is shut off.
Heating that is operated with fuel, such as tank liquid heating, is shut off. The coupling of the mechanical turbocharger is released, so that the turbocharger no longer loads the engine. In the gasoline direct injection type engine, the efficiency reduction engagement by the throttle valve, for example, the homogeneous operation for catalyst regeneration is prohibited.

[Brief description of the drawings]

FIG. 1 is an overall block circuit diagram of a control unit for controlling a vehicle drive unit.

FIG. 2 is a flowchart of a preferred embodiment in execution of a computer program of a control unit.

[Explanation of symbols]

 Reference Signs List 10 control unit 12 input circuit 14 microcomputer 16 outlet circuit 18 communication system 22 level gauge 24 fuel tank 32, 36 measuring device (operating variable) 38 throttle valve 42 turbocharger 46 transmission 50 fuel supply and / or ignition angle adjustment Element 56 Low tank lamp

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 45/00364 F02D 45/00 364Q F02M 37/00 301 F02M 37/00 301R

Claims (7)

[Claims] 1. A method for controlling a drive unit, wherein at least one control variable for controlling the drive unit is determined as a function of a driving variable, the control variable being determined by a vehicle capacity, a tank level, or a residual fuel. A control method of the drive unit, characterized in that it is a function of a value representing the remaining mileage of the driving unit. 2. The method according to claim 1, wherein the drive unit comprises an internal combustion engine and an automatic transmission. 3. The method according to claim 1, wherein the value is compared with a threshold value, and when the value falls below the threshold value, the tank low lamp is operated to flash. 4. The system according to claim 1, wherein the value is compared with a threshold value, and when the value falls below the threshold value, an efficiency optimization control or a fuel consumption optimization control of the drive unit is performed. The method according to any one of claims 3 to 3. 5. The method according to claim 1, wherein the value is compared with a threshold value for causing the lamp to blink or a threshold value for optimizing the drive unit. 5. The method according to claim 1, wherein the low tank ramp is operated continuously. 6. The following measures are taken for the optimization control of the drive unit: reduction of the supply pressure, locking of the over-boost function, minimum possible supply pressure at the maximum possible throttle opening of the driver. Efficiency optimization of air supply pressure and throttle valve opening, engine charge, rotation speed, travel speed, torque and / or vehicle acceleration, switching to lean operation, locking of kick-down function, In the automatic engine start system by selecting the driving stage or gear stage that prioritizes efficiency, and in the automatic engine start system by operating the clutch, when idling and when not operating the clutch pedal
Automatic engine shutdown, especially after a short waiting time, disconnection of the air-conditioning compressor, disconnection of electric heating, disconnection of heating operated with fuel, release of the coupling of the mechanical turbocharger, and in gasoline direct injection engines, 6. The method according to claim 1, wherein at least one of prohibition of reduced efficiency engagement by a throttle valve is performed. 7. A control device for a drive unit, comprising a control unit (10) for determining at least one control variable for control of the drive unit as a function of at least one operating variable, the control unit comprising: A control device for a drive unit, which determines values representing a quantity, a tank level or a remaining mileage, and determines a control quantity as a function of these values.