RU2491460C2 - Method and system for control of transmission at low power - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: proposed system comprises means of detecting the situation when low drive power is required and means for gearbox shifting to high gear. Proposed method consists in detecting occurrence of situation when low power under preset vehicle drive power is required. Gearbox is shifted to high gear to make vehicle go at engine speed. Engine speed is lower than plateau of high-gear torque characteristic. Vehicle with engine drive incorporates above described control system.

EFFECT: fuel savings.

11 cl, 3 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to a method and system for controlling a gearbox connected to an internal combustion engine. The invention relates, in particular, to a method and a control system for a gearbox attached to an internal combustion engine when it is determined that a situation has occurred or will soon come when a low power is required.

BACKGROUND OF THE INVENTION

Management of the engine and gearbox in a motor vehicle includes controlling engine speed and gear selection partly with the help of driver commands and partly with control units designed to optimize engine performance in terms of fuel economy, exhaust emissions, etc. The control unit, usually called an ECU (electronic control unit), receives sensor signals from various parts of the drive line, and the engine and gearbox are controlled based on these signals and driver commands.

When traveling long distances, optimizing fuel consumption is especially important. To this end, so-called heavy vehicles have been developed with optimized engine speed for a specific cruising speed. Typical cruising speeds can be 80, 85 or 89 km / h. To achieve significant fuel economy, the car is adapted to engine speed, which provides an average gentle portion of the torque characteristic when driving at cruising speed.

Optimization of fuel consumption is always desirable, therefore, there is a need to reduce fuel consumption in cars driven by internal combustion engines.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method and system that reduces fuel consumption in an internal combustion engine that drives a motor vehicle.

The present invention provides a method for controlling a gearbox connected to an internal combustion engine that drives a motor vehicle. This method first determines the presence or imminent occurrence of a situation when low power is required below a certain threshold value for a moving car. If such a situation arises, the gearbox shifts to high gear so that the car moves at an engine speed lower than the gentle portion of the torque characteristic for high gear. As a result, there is no need to supply fuel, for example diesel fuel, in cases where the engine is diesel, when the engine is running in high gear, i.e. the engine is coasting.

In one embodiment of the invention, the predictive function is used to suggest when high gear can be engaged or when it needs to be shut off to enable the vehicle to travel at cruising speed with minimal fuel.

The invention relates to a car and computer software product designed for effective control in accordance with the method described above.

Using this method, a car and a computer program product in accordance with the invention lead to less parasitic losses during car movement, which leads to less fuel consumption of the car driven by an internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in more detail below based on non-limiting examples with reference to the accompanying drawings, in which:

Figure 1 depicts a General partial view of the engine;

Figure 2 depicts a torque curve indicating the operating range for transmission; and

Figure 3 is a flowchart illustrating the steps of controlling an engine in a motor vehicle.

DESCRIPTION OF PREFERRED EMBODIMENTS

1 schematically depicts selected portions of a drive line 100 in a motor vehicle 10. The drive line shown in FIG. 1 may, for example, be configured to form part of a truck or other heavy vehicle, for example, a bus and the like. The engine 101 forms part of the drive line 100. The engine is also connected to a semi-automatic gearbox 105.

The engine 101 and gearbox 105 are controlled by at least one control unit 107, for example, an electronic control unit (ECU). The control unit is designed to receive sensor signals from different parts of the car, including the gearbox and engine. The control unit 107 is also designed to supply control signals to various parts and components of the car, for example to the engine, including, but not limited to, transmission control signals. The control unit 107 is further able to receive data from the so-called “predictive” (LA) function of the function 103. The predictive function provides the control unit with information, inter alia, about the nature of the road ahead of the vehicle. For example, using the predictive function, you can get information about the slope of the road.

The operation of the various parts and components of the vehicle, in particular the transmission compartment, is controlled by pre-programmed instructions in the control unit. Pre-programmed instructions are typically in the form of a computer program product 109 recorded on a digital storage device such as random access memory (RAM), flash memory (EPROM - erasable programmable read-only memory, EEPROM - electrically erasable programmable read-only memory) or read-only memory device (ROM), and are executed using the control unit. The behavior of the car in a specific situation can be adapted by replacing pre-programmed instructions.

The gearbox 105 in the vehicle 10 is equipped with at least one high gear designed to operate in a range below the flat portion of the torque characteristic for transmission. The car, therefore, cannot be powered when this high gear is engaged, since the speed of the car will be too low to provide the necessary torque in this operating mode. The objective of such a transmission is to minimize spurious losses and, consequently, fuel consumption in operating modes, when low power is required. For example, if the car moves at an angle down, a high gear is selected and the engine saves fuel, at the same time, the engine speed drops to a very small value and the engine noise level decreases. If the control unit is equipped with data on the nature of the road in front of the car, a high gear can be engaged at an optimal time without recognizing engine signals to determine that low power is required. For example, if a control unit is connected to receive road data from a predictive function, the data of this function can be used to determine when a high gear needs to be connected.

Figure 2 depicts a torque curve and an operating range for high transmission, as described above. It is shown here that the engine will not give power when this gear is engaged. For example, if a car moves at a speed of 80 km / h and requires little power, a high gear can be selected and the car will save fuel. The engine will thus operate at a very low speed below the gentle portion of the torque characteristic, as shown in FIG. 2. When it is then necessary to receive power from the engine, the control unit shifts to a lower gear.

Figure 3 depicts a block diagram of the steps carried out during engine control, as described above. Low power requirements can typically be defined as power requirements below a specific setpoint. The setpoint may be a proportion, for example, 10-15% of the maximum power. For example, control signals from the engine can be used to determine the low required power at the moment for the movement of the car. According to an embodiment, the data in front of the car is used to determine that at the moment little power is needed to move the car. In particular, information from a predictive function may be used. When it is determined that low engine power is required for the car to move, the gearbox is shifted to a higher gear, which is not operational, in step 303, i.e. the engine speed on it is lower than the gentle portion of the torque characteristic when the car is moving at cruising speed, for example, from 80 to 90 km / h.

After this, continuous monitoring is carried out at step 305 over whether it is required to obtain power from the engine. For example, pressing the accelerator pedal by the driver and / or engine control signals can be used to determine that there is a need for power. If the control unit 107 has access to road data, this data can be used to determine if power will soon be needed. If at step 305 it turns out that power is currently required or may soon be required, the engine switches to low gear at step 307, otherwise the engine will continue to operate with the high gear connected.

Using this method, an automobile and a computer program product, as described herein, result in low fuel consumption by an automobile driven by an internal combustion engine. This is due to the fact that there is no need to supply fuel to the internal combustion engine when it moves at a low speed below a gentle portion of the torque characteristic, i.e. the car is coasting.

Claims (11)

1. The method of controlling a gearbox (105) connected to an internal combustion engine (100), which drives a motor vehicle (10), characterized by the following steps: determining (301) whether or not a situation is about to occur, when low power is required below a certain set value for the movement of the car, and shifting the gearbox (303) to a high gear so that the car moves at an engine speed that is lower than the gentle portion of the torque characteristic for high gear cottages, on the basis of determining that the situation has arrived or will soon come when a small power is required for the movement of the car. 2. The method according to claim 1, characterized in that the determination of what has come or will soon come the requirement of low power for the movement of the car is based on data taking into account the slope of the road in front of the car. 3. The method according to claim 1 or 2, characterized in that the determination of what has come or will soon come the requirement of low power for the movement of the car is based on data on the nature of the road in front of the car. 4. The method according to claim 1, characterized in that the determination of what has come or will soon come the requirement of low power for the movement of the car is based on control signals to and / or from the engine. 5. The method according to any one of claims 1 to 4, characterized by the step of continuously monitoring whether it is necessary or in the near future to receive power from the engine, and if so, shifting the gear to a lower one. 6. A control system for controlling a gearbox (105) connected to an internal combustion engine (100) that drives a motor vehicle (10), characterized in that it comprises: means (107) for determining the occurrence or imminent occurrence of a situation when low power is required below a certain predetermined value for the movement of the car, and means (107) for shifting the gearbox to high gear so that the engine moves at an engine speed that is lower than a gentle portion of the twisting characteristic present moment for high transmission, based on the determination that a situation has arrived or will soon come when a low power is required for the car to move. 7. The control system according to claim 6, characterized in that it contains means for determining the onset or imminent onset of the low power requirement for vehicle movement based on data taking into account the slope of the road in front of the car. 8. The control system according to claim 6 or 7, characterized in that it contains means for determining the onset or imminent onset of the low power requirement for vehicle movement based on data on the nature of the road in front of the vehicle. 9. The control system according to claim 6, characterized in that it contains means for determining the onset or imminent onset of the low power requirement for vehicle movement based on control signals to or from the engine. 10. A control system according to any one of claims 6 to 9, characterized in that it comprises means (107) for continuously monitoring what is required or will soon need to receive power from the engine, and means (107) for shifting to a lower gear, when it is required or soon it will be required to receive power from the car. 11. An automobile (10) driven by an engine, comprising a control system according to any one of claims 6-10.

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