JP2007120334A - Abnormality diagnostic device of vehicle driving system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect abnormality of driving force of a vehicle. <P>SOLUTION: A required vehicle driving energy consumption rate (energy consumption per unit time required for driving a vehicle by the driving force required by a driver) is calculated based on an accelerator operation quantity, and an actual vehicle driving energy consumption rate (energy consumption per unit time consumed for driving the vehicle) is calculated based on a fuel injection quantity, and the existence of abnormality of vehicle driving force is determined by whether or not the actual vehicle driving energy consumption rate is larger by a determined value or more than the required vehicle driving energy consumption rate. Thus, abnormality of clearly increasing the vehicle driving force more than a requirement of the driver, can be accurately detected without receiving influence of a power transmission system and an operation area. When determining that these is abnormality of the vehicle driving force, fail-safe control is performed for restraining the actual vehicle driving energy consumption rate, and the vehicle can be made to safely retreat and travel while preventing sudden acceleration against the will of the driver. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an abnormality diagnosing device for a vehicle drive system that determines the presence or absence of an abnormality in a vehicle drive system that controls a power source such as an internal combustion engine mounted on the vehicle to control the drive force of the vehicle.

  In a vehicle equipped with an internal combustion engine, as described in Patent Document 1 (Japanese Patent No. 3392787), the maximum allowable torque of the internal combustion engine is calculated based on the accelerator operation amount, and the operating state of the internal combustion engine is set. In some cases, the actual torque of the internal combustion engine is calculated based on this, and the presence or absence of an abnormality is determined based on whether or not the actual torque exceeds a maximum allowable torque.

Further, as described in Patent Document 2 (US Pat. No. 5,987,372), the required driving force is calculated based on the accelerator operation amount, the actual driving force is calculated based on the wheel speed, and the required driving force is calculated. In some cases, the presence or absence of an abnormality is determined based on whether or not the deviation between the actual driving force and the actual driving force is greater than an abnormality determination value.
Japanese Patent No. 3392787 US Pat. No. 5,987,372

  By the way, the driving force of the vehicle is not determined only by the torque of the internal combustion engine, but varies depending on the state of the power transmission system such as a transmission. Therefore, the driving force of the vehicle cannot be accurately evaluated with the torque of the internal combustion engine. For this reason, in the abnormality diagnosis which determines the presence or absence of abnormality using the actual torque of an internal combustion engine like the said patent document 1, there exists a fault that abnormality of the driving force of a vehicle cannot be detected accurately.

  In general, the wheel speed detection device detects the wheel speed from the interval of the wheel speed pulse output from the wheel speed sensor in synchronization with the rotation of the wheel, and accurately detects the interval of the wheel speed pulse even during high speed driving. Since the interval between the wheel speed pulses is set so as to be able to be performed, in the low-speed operation region where the rotation of the wheel is slow, the interval between the wheel speed pulses becomes too long and the detection accuracy of the wheel speed tends to be lowered. For this reason, in the abnormality diagnosis method for determining the presence / absence of abnormality using the actual driving force calculated based on the wheel speed as in Patent Document 2, a low-speed driving region in which drivability is greatly deteriorated due to an abnormality in the driving force of the vehicle. Thus, there is a drawback that the accuracy of calculating the actual driving force is lowered and the accuracy of abnormality diagnosis is lowered.

  The present invention has been made in consideration of these circumstances. Therefore, the object of the present invention is to provide a vehicle capable of accurately detecting an abnormality in the driving force of the vehicle without being influenced by the power transmission system or the driving region. An object of the present invention is to provide a drive system abnormality diagnosis device.

  To achieve the above object, the invention according to claim 1 is a unit consumed for driving a vehicle in a vehicle drive system that controls a power source mounted on the vehicle to control the driving force of the vehicle. The energy consumption per hour (hereinafter referred to as “actual vehicle drive energy consumption rate”) is calculated by the actual vehicle drive energy consumption rate calculation means, and the unit time required to drive the vehicle with the driving force required by the driver The energy consumption per unit (hereinafter referred to as “required vehicle drive energy consumption rate”) is calculated by the required vehicle drive energy consumption rate calculation means, and the actual vehicle drive energy consumption rate is compared with the required vehicle drive energy consumption rate by the abnormality diagnosis means. Thus, it is determined whether or not there is an abnormality in the driving force of the vehicle.

  The actual vehicle driving energy consumption rate is information on the actual vehicle driving force, and the required vehicle driving energy consumption rate is information on the vehicle driving force requested by the driver. Therefore, the actual vehicle driving energy consumption rate and the required vehicle driving energy are By comparing the consumption rate, it is possible to evaluate the relationship between the actual vehicle driving force and the vehicle driving force required by the driver without being affected by the power transmission system and the driving region. It is possible to determine whether or not is appropriate for the vehicle driving force requested by the driver. Accordingly, it is possible to accurately determine whether there is an abnormality in the driving force of the vehicle without depending on the power transmission system and the driving region, and to detect the abnormality in the driving force of the vehicle with high accuracy.

  In this case, as in claim 2, when the actual vehicle driving energy consumption rate becomes larger than the required vehicle driving energy consumption rate by the determination value or more, it is determined that the vehicle driving force is abnormal, and the vehicle driving force is abnormal. It is preferable to execute fail-safe control that suppresses the actual vehicle driving energy consumption rate when it is determined. Here, the determination value may be set in consideration of a control error or the like. In short, when the deviation between the actual vehicle drive energy consumption rate and the required vehicle drive energy consumption rate exceeds the control error range, it is determined that there is an abnormality in the vehicle drive force and the actual vehicle drive energy consumption rate is suppressed. The fail safe control is executed. In this way, when an abnormality occurs that causes the actual vehicle driving force to exceed the vehicle driving force control error range required by the driver, the vehicle driving force can be retracted by fail-safe control. Thus, the vehicle can be safely evacuated while preventing sudden acceleration against the will of the driver.

  Further, when the internal combustion engine is mounted as a power source of the vehicle as in claim 3, the actual vehicle drive energy consumption rate is calculated based on the fuel consumption per unit time of the internal combustion engine. good. In a vehicle that uses an internal combustion engine as a power source, the fuel per unit time of the internal combustion engine is driven in order to drive the vehicle by converting the combustion energy of the fuel into mechanical rotational energy (energy for driving the vehicle) in the internal combustion engine. If the consumption amount is used, the actual vehicle driving energy consumption rate can be calculated with high accuracy.

  On the other hand, when a motor is mounted as a power source of the vehicle as in claim 4, the actual vehicle driving energy consumption rate is based on the electric energy consumption per unit time of the battery that supplies electric energy to the motor. Should be calculated. In a vehicle (so-called electric vehicle) using a motor as a power source, electric energy is converted into mechanical rotational energy by the motor to drive the vehicle. Therefore, if the electric energy consumption per unit time of the battery is used, the actual vehicle The driving energy consumption rate can be calculated with high accuracy.

  Further, when the internal combustion engine and the motor are mounted as the power source of the vehicle as in claim 5, the fuel consumption per unit time of the internal combustion engine and the unit of the battery that supplies electric energy to the motor The actual vehicle driving energy consumption rate may be calculated based on the electric energy consumption per hour. In a vehicle (so-called hybrid vehicle) using an internal combustion engine and a motor as power sources, the vehicle is driven by converting combustion energy of fuel into rotational energy by the internal combustion engine, or by converting electric energy into rotational energy by the motor. If the fuel consumption per unit time and the electric energy consumption per unit time are used, the actual vehicle drive energy consumption rate can be calculated with high accuracy.

  Generally, as the driver's accelerator operation amount (accelerator pedal depression amount) increases, the vehicle driving force required by the driver increases. Therefore, when calculating the required vehicle driving energy consumption rate, as in claim 6 The required vehicle drive energy consumption rate may be calculated based on the accelerator operation amount of the driver. In this way, the required vehicle driving energy consumption rate corresponding to the vehicle driving force required by the driver can be calculated with high accuracy.

  Hereinafter, the best mode for carrying out the present invention will be described using three Examples 1 to 3.

A first embodiment in which the present invention is applied to a vehicle that uses an internal combustion engine as a power source will be described with reference to FIGS.
First, a schematic configuration of the entire engine control system will be described with reference to FIG. An air cleaner 13 is provided at the most upstream portion of the intake pipe 12 of the engine 11 that is an internal combustion engine, and an air flow meter 14 that detects the intake air amount is provided downstream of the air cleaner 13. A throttle valve 16 whose opening is adjusted by a motor 15 and a throttle opening sensor 17 for detecting the opening (throttle opening) of the throttle valve 16 are provided on the downstream side of the air flow meter 14. The throttle opening sensor 17 is composed of a double sensor having a main sensor and a sub sensor.

  Further, an intake manifold 18 that introduces air into each cylinder of the engine 11 is provided on the downstream side of the throttle valve 16, and a fuel injection valve 19 that injects fuel near each intake port of the intake manifold 18 of each cylinder. It is attached. Further, a spark plug 20 is attached to each cylinder of the cylinder head of the engine 11, and the air-fuel mixture in the cylinder is ignited by spark discharge of each spark plug 20.

  A crank angle sensor 22 that outputs a crank angle signal (pulse signal) every time the crankshaft 21 rotates a predetermined crank angle is attached to the cylinder block of the engine 11. Based on the crank angle signal of the crank angle sensor 22, the crank angle and the engine speed are detected. Further, the accelerator operation amount (depressed amount of the accelerator pedal 24) is detected by the accelerator sensor 23. The accelerator sensor 23 is composed of a double sensor having a main sensor and a sub sensor.

  Outputs of these various sensors are input to an engine control circuit (hereinafter referred to as “ECU”) 25. The ECU 25 is mainly composed of a microcomputer including a CPU 26, a ROM 27, a RAM 28, and the like, and executes various engine control programs stored in the ROM 27, so that the fuel injection of the fuel injection valve 19 is performed in accordance with the engine operating state. The amount and ignition timing of the spark plug 20 are controlled.

  At that time, the ECU 25 calculates the target throttle opening based on the accelerator operation amount detected by the accelerator sensor 23, and adjusts the throttle valve so that the actual throttle opening detected by the throttle opening sensor 17 coincides with the target throttle opening. The output of the engine 11 is controlled by controlling the 16 motors 15. The output of the engine 11 is transmitted to the drive wheels of the vehicle via an automatic transmission (not shown) or the like. Thereby, the output of the engine 11 is controlled according to the accelerator operation amount of the driver, and the driving force of the vehicle is controlled.

  This abnormality diagnosis of the vehicle drive system is executed by the ECU 25 as follows according to the abnormality diagnosis program of FIG. As shown in FIG. 2, the required vehicle drive energy consumption rate is calculated based on the accelerator operation amount and the like, and the actual vehicle drive energy consumption rate is calculated based on the fuel injection amount and the like. Here, the actual vehicle driving energy consumption rate is the energy consumption per unit time consumed to actually drive the vehicle, and the required vehicle driving energy consumption rate is the driving force requested by the driver. This is the energy consumption per unit time required for driving. Thereafter, the actual vehicle drive energy consumption rate is compared with the required vehicle drive energy consumption rate to determine whether or not the actual vehicle drive energy consumption rate exceeds the required vehicle drive energy consumption rate.

  The actual vehicle driving energy consumption rate becomes information on the actual vehicle driving force, and the required vehicle driving energy consumption rate becomes information on the vehicle driving force requested by the driver. Therefore, the actual vehicle driving energy consumption rate becomes the required vehicle driving energy. Whether the actual vehicle driving force is greater than the vehicle driving force requested by the driver without being affected by the power transmission system or driving region by determining whether or not the consumption rate has been exceeded. It can be determined whether or not.

  As a result, when it is determined that the actual vehicle driving energy consumption rate exceeds the required vehicle driving energy consumption rate, the actual vehicle driving force is an abnormal state that is greater than the vehicle driving force requested by the driver. It is determined that there is an abnormality in the vehicle driving force. Furthermore, when it is determined that there is an abnormality in the vehicle driving force, fail-safe control for suppressing the actual vehicle driving energy consumption rate is executed. In this fail-safe control, the fuel injection amount is limited, the throttle opening is limited to limit the intake air amount, and the output of the engine 11 is suppressed. The driving force is suppressed to such an extent that the vehicle can evacuate.

  Next, a specific calculation method of the required vehicle driving energy consumption rate and the actual vehicle driving energy consumption rate will be described. When calculating the required vehicle drive energy consumption rate, referring to the map of the required vehicle drive energy consumption rate shown in FIG. 3, the required vehicle drive according to the current accelerator operation amount and the vehicle speed (or engine speed). Calculate the energy consumption rate. In general, as the driver's accelerator operation amount increases, the vehicle driving force required by the driver increases and the required vehicle driving energy consumption rate increases, so the map of the required vehicle driving energy consumption rate increases as the accelerator operation amount increases. The required vehicle drive energy consumption rate is set to be large. The required vehicle drive energy consumption rate map is set in advance based on test data, design data, and the like, and is stored in the ROM 27 of the ECU 25.

  On the other hand, when calculating the actual vehicle drive energy consumption rate, as shown in FIG. 2, first, the total energy consumption rate, the heat / mechanical loss energy consumption rate, and the accessory drive energy consumption rate are calculated. Here, the total energy consumption rate is the total energy consumption per unit time consumed by the vehicle. The heat / mechanical loss energy consumption rate is the energy consumption per unit time consumed as heat and mechanical loss, and the auxiliary drive energy consumption rate drives auxiliary equipment such as air conditioners, power steering and alternators. It is the energy consumption per unit time consumed to do. Thereafter, the actual vehicle drive energy consumption rate is obtained by subtracting the heat / mechanical loss energy consumption rate and the accessory drive energy consumption rate from the total energy consumption rate.

In a vehicle using the engine 11 as a power source, the amount of combustion energy consumed per unit time (combustion energy consumption rate) is substantially equal to the total energy consumption rate. Therefore, when calculating the total energy consumption rate, The fuel consumption per unit time is obtained by multiplying the fuel injection amount per revolution (360 ° C. A) by the engine rotation speed, and the fuel consumption amount per unit time is multiplied by a predetermined coefficient. Is determined as the total energy consumption rate.
Total energy consumption rate = (fuel injection amount / 1 rotation) x engine rotation speed x coefficient

  When calculating the heat / mechanical loss energy consumption rate, refer to the heat / mechanical loss energy consumption rate map shown in FIG. 4 and calculate the heat / mechanical loss energy consumption rate according to the current cooling water temperature. To do. Generally, the coolant temperature increases as the engine temperature increases. Further, as the engine temperature increases, the heat energy consumed by warming up the engine 11 and its peripheral parts decreases, and as the engine temperature increases, the viscosity of the lubricating oil decreases and the frictional force decreases, resulting in mechanical loss. Less energy is consumed. Therefore, the heat / mechanical loss energy consumption rate map is set such that the heat / mechanical loss energy consumption rate decreases as the coolant temperature increases (that is, the engine temperature increases). This heat / mechanical loss energy consumption rate map is set in advance based on test data, design data, and the like, and is stored in the ROM 27 of the ECU 25. Instead of the cooling water temperature, other temperature information such as engine temperature and oil temperature may be used.

  Further, when calculating the auxiliary machine drive energy consumption rate, as shown in FIG. 5, the air conditioner drive energy consumption rate (energy consumption per unit time consumed to drive the air conditioner) and the power steering drive energy consumption are calculated. Rate (energy consumption per unit time consumed to drive the power steering) and alternator drive energy consumption rate (energy consumption per unit time consumed to drive the alternator) are calculated. The auxiliary machine drive energy consumption rate is obtained by adding the air conditioner drive energy consumption rate, the power steering drive energy consumption rate, and the alternator drive energy consumption rate.

  In a vehicle using the engine 11 as a power source, the engine 11 converts the combustion energy of fuel into mechanical rotational energy (energy for driving the vehicle) to drive the vehicle. At this time, not all of the combustion energy is consumed as energy for driving the vehicle, but a part of the combustion energy is consumed as heat energy, mechanical loss energy, and auxiliary machine drive energy. Therefore, the actual vehicle drive energy consumption rate is calculated by subtracting the heat / mechanical loss energy consumption rate and the auxiliary drive energy consumption rate from the total energy consumption rate calculated based on the fuel consumption per unit time (that is, the combustion energy consumption rate). Can be requested.

The vehicle drive system abnormality diagnosis described above is executed by the ECU 25 according to the abnormality diagnosis program of FIG. The processing contents of this abnormality diagnosis program will be described below.
The abnormality diagnosis program shown in FIG. 6 is executed at a predetermined cycle while the ECU 25 is powered on. When this program is started, first, in step 101, the requested vehicle corresponding to the current accelerator operation amount and vehicle speed (or engine speed) is referred to with reference to the map of the requested vehicle driving energy consumption rate shown in FIG. The drive energy consumption rate is calculated. The processing in step 101 serves as a required vehicle driving energy consumption rate calculating means in the claims.

  Thereafter, the process proceeds to step 102, where the fuel injection amount per rotation of the engine 11 is multiplied by the engine rotation speed to obtain the fuel consumption amount per unit time, and the fuel consumption amount per unit time is multiplied by a predetermined coefficient. Then, after obtaining the total energy consumption rate (that is, the combustion energy consumption rate), the process proceeds to step 103, and the heat / mechanical loss energy consumption rate map shown in FIG. Calculate the mechanical loss energy consumption rate.

  Thereafter, the process proceeds to step 104, where the air conditioner drive energy consumption rate, the power steering drive energy consumption rate, and the alternator drive energy consumption rate are calculated, respectively, and the air conditioner drive energy consumption rate, the power steering drive energy consumption rate, and the alternator drive energy consumption rate are calculated. Is added to obtain the auxiliary machine drive energy consumption rate.

  Thereafter, the process proceeds to step 105, where the actual vehicle drive energy consumption rate is obtained by subtracting the heat / mechanical loss energy consumption rate and the accessory drive energy consumption rate from the total energy consumption rate. The processing of these steps 102 to 105 serves as an actual vehicle driving energy consumption rate calculating means in the claims.

  Thereafter, the process proceeds to step 106, where it is determined whether or not the actual vehicle drive energy consumption rate is larger than the required vehicle drive energy consumption rate by the determination value α. If “No” is determined, the process proceeds to step 107. It is determined that there is no abnormality (normal) in the driving force. Here, the determination value α is set in consideration of a control error or the like. In short, the presence / absence of an abnormality in the vehicle driving force is determined based on whether or not the deviation between the required vehicle driving energy consumption rate and the actual vehicle driving energy consumption rate exceeds the control error range.

  On the other hand, if it is determined in step 106 that the actual vehicle driving energy consumption rate is larger than the required vehicle driving energy consumption rate by the determination value α or more, the actual vehicle driving force requested by the driver is determined. It is determined that the driving force is in an abnormal state that exceeds the control error range, and the process proceeds to step 108 where it is determined that the vehicle driving force is abnormal and the abnormality flag is set to ON. Further, a warning lamp (not shown) provided on the instrument panel of the driver's seat is turned on, or a warning is displayed on a warning display section (not shown) of the instrument panel of the driver's seat to warn the driver. At the same time, the abnormality information (abnormality code or the like) is stored in a rewritable nonvolatile memory such as a backup RAM (not shown) of the ECU 25. The processing of these steps 106 to 108 plays a role as abnormality diagnosis means in the claims.

  Thereafter, the process proceeds to step 109, and fail-safe control for suppressing the actual vehicle driving energy consumption rate is executed. In this fail-safe control, the actual vehicle drive energy consumption rate is suppressed by correcting the decrease in the fuel injection amount, or decreasing the throttle opening to reduce the intake air amount and suppressing the output of the engine 11. Thus, the driving force of the vehicle is suppressed to such an extent that the vehicle can evacuate. The processing in step 109 serves as fail-safe control means in the claims.

  In the first embodiment described above, the required vehicle drive energy consumption rate is calculated based on the accelerator operation amount and the like, and the actual vehicle drive energy consumption rate is calculated based on the fuel injection amount and the like. Is determined to be greater than the required vehicle drive energy consumption rate by a determination value α or more, so that the presence or absence of an abnormality in the driving force of the vehicle is determined. It is possible to determine whether or not the vehicle driving force is in an abnormal state where the vehicle driving force increases beyond the control error range of the vehicle driving force requested by the driver. Accordingly, it is possible to accurately determine whether there is an abnormality in the driving force of the vehicle without depending on the power transmission system and the driving region, and to detect the abnormality in the driving force of the vehicle with high accuracy.

  Further, in the first embodiment, when the actual vehicle driving energy consumption rate becomes larger than the required vehicle driving energy consumption rate by the determination value α or more, it is determined that the vehicle driving force is abnormal, and the actual vehicle driving energy consumption rate is determined. Therefore, when the actual vehicle driving force abnormality occurs, the driver's intention is to suppress the vehicle driving force to such an extent that the vehicle can evacuate. The vehicle can be safely evacuated while preventing sudden acceleration.

  In a vehicle using the engine 11 as a power source, the engine 11 converts the combustion energy of the fuel into mechanical rotational energy (energy for driving the vehicle) to drive the vehicle. At this time, not all of the combustion energy is consumed as energy for driving the vehicle, but a part of the combustion energy is consumed as heat energy, mechanical loss energy, and auxiliary machine drive energy.

  In consideration of such circumstances, in the first embodiment, the heat / mechanical loss energy consumption rate and the auxiliary machine drive energy are calculated from the total energy consumption rate (combustion energy consumption rate) calculated based on the fuel consumption per unit time. Since the actual vehicle drive energy consumption rate is obtained by subtracting the consumption rate, the actual vehicle drive energy consumption rate in a vehicle using the engine 11 as a power source can be calculated with high accuracy.

Next, a second embodiment in which the present invention is applied to a vehicle (so-called electric vehicle) using a motor as a power source will be described with reference to FIG.
As shown in FIG. 7, in the second embodiment, when the required vehicle drive energy consumption rate is calculated, the required vehicle drive energy consumption rate corresponding to the current accelerator operation amount and the vehicle speed (or motor rotation speed) is calculated. Calculate with maps.

  On the other hand, when calculating the actual vehicle drive energy consumption rate, the total energy consumption rate, heat / mechanical loss energy consumption rate, and auxiliary machine drive energy consumption rate are calculated. The electric energy consumption (electric energy consumption rate) per unit time of the battery supplying power is almost equal to the total energy consumption rate. Therefore, when calculating the total energy consumption rate, the battery voltage and current The electric energy consumption rate is calculated based on the above, and is set as the total energy consumption rate.

When calculating the heat / mechanical loss energy consumption rate, the heat / mechanical loss energy consumption rate corresponding to the current motor temperature (or information correlated therewith) is calculated using a map or the like.
Then, the actual vehicle drive energy consumption rate is obtained by subtracting the heat / mechanical loss energy consumption rate and the accessory drive energy consumption rate from the total energy consumption rate.

  Thereafter, it is determined whether or not the actual vehicle drive energy consumption rate is larger than the determination value by the requested vehicle drive energy consumption rate, and if the actual vehicle drive energy consumption rate is greater than the determination value by the requested vehicle drive energy consumption rate, Fail safe control is executed by determining that the actual vehicle driving force is in an abnormal state in which the actual vehicle driving force increases beyond the control error range of the vehicle driving force requested by the driver. In this fail-safe control, the drive voltage and drive current of the motor are limited to suppress the output of the motor, so that the actual vehicle drive energy consumption rate is suppressed and the drive force of the vehicle is suppressed to such an extent that the vehicle can evacuate. .

  In a vehicle using a motor as a power source, electric energy is converted into mechanical rotational energy (energy for driving the vehicle) by the motor to drive the vehicle. At that time, not all the electric energy consumed by the battery is consumed as energy for driving the vehicle, but a part of the electric energy consumed by the battery is heat energy, mechanical loss energy, auxiliary drive energy, or the like. As consumed.

  In consideration of such circumstances, in the second embodiment, the heat / mechanical loss energy consumption rate and the compensation are calculated from the total energy consumption rate (electric energy consumption rate) calculated based on the electric energy consumption per unit time of the battery. Since the actual vehicle drive energy consumption rate is determined by subtracting the machine drive energy consumption rate, the actual vehicle drive energy consumption rate in a vehicle using a motor as a power source can be calculated with high accuracy.

Next, a third embodiment in which the present invention is applied to a vehicle (so-called hybrid vehicle) using an engine and a motor as power sources will be described with reference to FIG.
As shown in FIG. 8, in the third embodiment, when the required vehicle drive energy consumption rate is calculated, it depends on the current accelerator operation amount and the vehicle speed (or at least one of the engine rotation speed and the motor rotation speed). The required vehicle drive energy consumption rate is calculated using a map or the like.

  In addition, in a vehicle using an engine and a motor as a power source, the sum of the combustion energy consumption rate and the electric energy consumption rate is substantially equal to the total energy consumption rate, so when calculating the actual vehicle drive energy consumption rate, The combustion energy consumption rate and the electric energy consumption rate are calculated, and the heat / mechanical loss energy consumption rate and the accessory driving energy consumption rate are calculated.

  The combustion energy consumption rate is obtained by multiplying the fuel injection amount per rotation of the engine 11 by the engine rotation speed to obtain the fuel consumption amount per unit time, and multiplying the fuel consumption amount per unit time by a predetermined coefficient. Obtain the combustion energy consumption rate. On the other hand, the electric energy consumption rate is calculated based on the voltage and current of the battery.

When calculating the heat / mechanical loss energy consumption rate, the heat / mechanical loss energy consumption rate corresponding to the current cooling water temperature or motor temperature is calculated using a map or the like.
Then, the actual vehicle drive energy consumption rate is obtained by subtracting the heat / mechanical loss energy consumption rate and the accessory drive energy consumption rate from the sum of the combustion energy consumption rate and the electric energy consumption rate (that is, the total energy consumption rate).

  Thereafter, it is determined whether or not the actual vehicle drive energy consumption rate is larger than the determination value by the requested vehicle drive energy consumption rate, and if the actual vehicle drive energy consumption rate is greater than the determination value by the requested vehicle drive energy consumption rate, Fail safe control is executed by determining that the actual vehicle driving force is in an abnormal state in which the actual vehicle driving force increases beyond the control error range of the vehicle driving force requested by the driver. In this fail-safe control, the fuel injection amount and intake air amount of the engine 11 are limited to suppress the output of the engine, and the motor driving voltage and driving current are limited to suppress the motor output. The driving energy consumption rate is suppressed, and the driving force of the vehicle is suppressed to such an extent that the vehicle can evacuate.

  In the third embodiment described above, in a vehicle using an engine and a motor as a power source, considering that the sum of the combustion energy consumption rate and the electrical energy consumption rate is the total energy consumption rate, Since the actual vehicle driving energy consumption rate is obtained by subtracting the heat / mechanical loss energy consumption rate and the accessory driving energy consumption rate from the sum of the electric energy consumption rate, the vehicle in which the engine 11 and the motor are used as power sources is used. The actual vehicle driving energy consumption rate can be calculated with high accuracy.

  In each of the first to third embodiments, it is determined that there is an abnormality in the vehicle driving force only when the actual vehicle driving energy consumption rate is greater than the required vehicle driving energy consumption rate by a determination value or more. Even when the vehicle drive energy consumption rate becomes smaller than the required vehicle drive energy consumption by a determination value or more, it may be determined that the vehicle drive force is abnormal.

  In addition, when the present invention is applied to a vehicle using an engine as a power source or a vehicle using an engine and a motor as a power source, the applicable range is not limited to a vehicle equipped with a gasoline engine, but to a vehicle equipped with a diesel engine. The present invention can also be applied. In addition, the present invention relates to any engine control of a mass flow method (a method of detecting the intake air amount of the engine with an air flow meter) and a speed density method (a method of calculating the intake air amount of the engine from the engine rotational speed and the intake pipe pressure). It can also be applied to the system.

  For the battery used as the energy source of the motor, a storage battery or a fuel cell may be used. Moreover, you may use the apparatus which has an electric power generation function instead of a battery.

It is a schematic block diagram of the whole engine control system in Example 1 of this invention. FIG. 2 is a functional block diagram schematically showing an abnormality diagnosis function of the ECU according to the first embodiment. It is a figure which shows notionally an example of the map of a request | requirement vehicle drive energy consumption rate. It is a figure which shows notionally an example of the map of a heat / mechanical loss energy consumption rate. It is a block diagram for demonstrating the calculation method of an auxiliary machinery drive energy consumption rate. It is a flowchart which shows the flow of a process of an abnormality diagnosis program. It is a functional block diagram which shows roughly the abnormality diagnosis function of ECU of Example 2. FIG. FIG. 6 is a functional block diagram schematically illustrating an abnormality diagnosis function of an ECU according to a third embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Intake pipe, 16 ... Throttle valve, 19 ... Fuel injection valve, 20 ... Spark plug, 23 ... Accelerator sensor, 25 ... ECU (actual vehicle drive energy consumption rate calculation means, demand vehicle drive) Energy consumption rate calculation means, abnormality diagnosis means, fail safe control means)

Claims (6)

In a vehicle drive system for controlling a driving force of a vehicle by controlling a power source mounted on the vehicle,
An actual vehicle driving energy consumption rate calculating means for calculating an energy consumption amount per unit time consumed for driving the vehicle (hereinafter referred to as “actual vehicle driving energy consumption rate”);
Requested vehicle drive energy consumption rate calculating means for calculating an energy consumption per unit time (hereinafter referred to as “required vehicle drive energy consumption rate”) required to drive the vehicle with the drive force requested by the driver;
An abnormality diagnosing means for comparing the actual vehicle driving energy consumption rate with the required vehicle driving energy consumption rate to determine whether there is an abnormality in the driving force of the vehicle. Diagnostic device. The abnormality diagnosing means determines that there is an abnormality in the driving force of the vehicle when the actual vehicle driving energy consumption rate is greater than a determination value more than the required vehicle driving energy consumption rate,
2. The apparatus according to claim 1, further comprising fail-safe control means for executing fail-safe control for suppressing the actual vehicle driving energy consumption rate when the abnormality diagnosis means determines that the driving force of the vehicle is abnormal. The abnormality diagnosis device for a vehicle drive system according to claim 1. An internal combustion engine is mounted as a power source of the vehicle,
3. The vehicle drive according to claim 1, wherein the actual vehicle drive energy consumption rate calculating means calculates the actual vehicle drive energy consumption rate based on a fuel consumption amount per unit time of the internal combustion engine. System abnormality diagnosis device. A motor is mounted as a power source of the vehicle,
2. The actual vehicle driving energy consumption rate calculating means calculates the actual vehicle driving energy consumption rate based on an electric energy consumption amount per unit time of a battery that supplies electric energy to the motor. Or the abnormality diagnosis apparatus of the vehicle drive system of 2. An internal combustion engine and a motor are mounted as power sources for the vehicle,
The actual vehicle drive energy consumption rate calculating means is configured to drive the actual vehicle based on a fuel consumption amount per unit time of the internal combustion engine and an electric energy consumption amount per unit time of a battery supplying electric energy to the motor. The abnormality diagnosis device for a vehicle drive system according to claim 1, wherein an energy consumption rate is calculated.   6. The vehicle drive system according to claim 1, wherein the required vehicle drive energy consumption rate calculating means calculates the required vehicle drive energy consumption rate based on a driver's accelerator operation amount. Abnormality diagnosis device.

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