JP6213306B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that controls a vehicle including an electric heater for heating.

  Generally, a vehicle is equipped with a heating device for heating the interior of the vehicle. The heat of the engine coolant is used as a heat source for the heating device. Cooling water heated by exhaust heat from the engine is guided to a heater core, which is a heat exchanger, and heats the air inside or outside the vehicle through the heater core for heating.

  However, in a situation where the engine load is small, such as when descending a long slope, the amount of exhaust heat of the engine is relatively small, so the amount of heat of the cooling water may not be sufficient for heating. In order to solve this problem, the vehicle heating device described in Patent Document 1 is configured to use an electric heating means (electric heating means) with electric power generated by a power generation device of an internal combustion engine (corresponding to an engine) when cooling water is equal to or lower than a predetermined set temperature. It is configured so that the air is heated via cooling water or directly.

  However, since the electric heater uses electric power generated by the power of the engine, the electric heater may not be sufficiently heated under a condition where the engine efficiency is low, and the heating may be insufficient. Further, if the exhaust heat amount of the engine is increased for heating, that is, if the engine output is increased, the cooling water can be heated to a temperature required for heating, but increasing the engine output only for heating It leads to deterioration of fuel consumption.

  On the other hand, the control device described in Patent Document 2 is configured such that the operating point of the engine is the intersection of the fuel consumption rate contour line and the fuel efficiency optimum line.

JP-A-6-344863 JP2013-163494A

  However, the contour line of the fuel consumption rate used in Patent Document 2 considers only the shaft output, and does not consider the heat output used for heating the cooling water. Therefore, the intersection of the contour line and the fuel efficiency optimum line may not be optimal as the operating point of the engine taking heating into consideration.

  This invention is made | formed in view of the said problem, and it aims at obtaining sufficient heating effect, suppressing the deterioration of a fuel consumption.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate a corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the invention. Not what you want.

In order to achieve the above object, the present invention provides a vehicle control device that heats and heats an electric heater (50) in accordance with a driving state of an engine (20), and outputs the vehicle for running and power generation. An engine efficiency calculation unit for calculating an engine efficiency (P) calculated from an engine output (E) obtained by adding a certain shaft output and a heat output for heating the cooling water, and a fuel consumption (F) ( 13) and an operating point determination unit (14) for determining the operating point of the engine, and the operating point determination unit is operated by the engine efficiency calculation unit based on the shaft output database (11) and the heat output database (12). Based on the calculated engine efficiency (P), an operating point corresponding to the required engine output is determined, a shaft output (Ea + Eb + Ec) corresponding to the operating point, and drive energy (Ea) provided for traveling , Energy (Eb), which is subjected to charging, and heating energy required for heating (Ec + Ed), on the basis of the heating energy, a heater power appropriated as power contained electric heater in the axial output (Ec), heat output (Ed), are characterized and Turkey be distributed.

  According to this, since the heat output is taken into account in the calculation of the engine efficiency, the fuel consumption is reduced as compared with the conventional configuration in which the engine operating point is determined using the engine efficiency only considering the shaft output. The operating point that is more optimal can be selected.

It is a block diagram which shows schematic structure of the vehicle control apparatus which concerns on 1st Embodiment, and its peripheral device. It is a figure which shows the calculation result of engine efficiency. It is a figure which shows the equal efficiency curve of the engine efficiency with respect to the rotation speed and torque of an engine. It is a flowchart which shows operation | movement of a vehicle control apparatus. It is a conceptual diagram of determination of an engine operating point. It is a block diagram which shows schematic structure of the vehicle control apparatus which concerns on 2nd Embodiment, and its peripheral device. It is a flowchart which shows operation | movement of a vehicle control apparatus. It is a conceptual diagram of determination of an engine operating point. It is a block diagram which shows schematic structure of the vehicle control apparatus which concerns on other embodiment, and its peripheral device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are given to the same or equivalent parts.

(First embodiment)
Initially, with reference to FIGS. 1-3, schematic structure of the vehicle control apparatus which concerns on this embodiment is demonstrated.

  As shown in FIG. 1, an engine 20 is connected to the vehicle control apparatus 10 in the present embodiment. The engine 20 exhibits a driving force for the vehicle to travel, and supplies electric power for charging the battery 40 and heating the electric heater 50 via the generator 30. The exhaust heat of the engine 20 heats the heater core 60 through cooling water. The exhaust heat of the engine 20 corresponds to the heat output described in the claims. Hereinafter, the exhaust heat amount of the engine 20 is referred to as heat output.

  The vehicle interior is heated by heating the air introduced into the vehicle interior. Heating energy for this purpose is provided by exhaust heat (heat output) of the engine 20 and the electric heater 50. An example of a method of heating air is a method in which both the heater core 60 and the electric heater 50 are disposed in the air flow path, and heat is directly transferred from the heater core 60 and the electric heater 50 to the air. Another example is a method in which the cooling water of the engine 20 is heated by the heat output of the engine 20 and the heat generated by the electric heater 50, and the amount of heat of the cooling water is transferred to the air via the heater core 60. Regardless of which method is employed, the heating energy in the present embodiment is provided by the heat output of the engine 20 and the amount of heat of the electric heater 50.

  The vehicle control device 10 in the present embodiment is configured to appropriately distribute the heat output constituting the heating energy and the heat amount of the electric heater 50. Hereinafter, a detailed configuration of the vehicle control device 10 will be described.

  The vehicle control device 10 includes a shaft output database 11 that stores driving efficiency information related to shaft output of the engine 20 and a heat output database 12 that stores information on heat output for each driving state of the engine 20. The vehicle control device 10 also includes an engine efficiency calculation unit 13 and an operating point determination unit 14. Furthermore, a heating energy calculation unit 15 that calculates the amount of heat necessary for heating is provided.

  The shaft output database 11 stores information on shaft output corresponding to engine torque and rotational speed, and information obtained by dividing the shaft output by fuel consumption at the torque and rotational speed, that is, driving efficiency. Device. The driving efficiency is obtained in advance by experiments or the like.

  The thermal output database 12 is a storage device in which information on thermal output corresponding to the engine torque and the rotational speed is stored. The heat output is obtained in advance through experiments or the like.

  The engine efficiency calculation unit 13 is a part that calculates the engine output E per unit fuel consumption as the engine efficiency P. The engine output E includes driving energy Ea for traveling the vehicle, energy Eb used for charging the battery 40, and energy Ec used for generating heat from the electric heater 50 (corresponding to the heater power described in the claims). And the sum of the thermal outputs Ed (E = Ea + Eb + Ec + Ed). The engine efficiency calculation unit 13 calculates the engine efficiency P (= E / F) based on the fuel consumption amount F and the engine output E. In addition, the shaft output described in the claims corresponds to Ea + Eb + Ec.

  The engine efficiency calculation unit 13 calculates the engine efficiency P based on the drive efficiency information stored in the shaft output database 11 and the heat output information stored in the heat output database 12. As shown in FIG. 2, for example, the calculation results are as follows: each energy Ea, Eb, Ec, Ed, the fuel consumption F consumed to output these energy, and the engine corresponding to the energy and fuel consumption The efficiency P is listed. The fuel consumption F in FIG. 2 is shown as a value converted into kilowatts.

  Note that the combinations of the energies Ea, Eb, Ec, Ed shown in FIG. 2 correspond one-to-one with the rotational speed and torque of the engine 20. That is, if the number of rotations and torque of the engine 20 are determined to be unique, the combination of each energy Ea, Eb, Ec, Ed is determined to be unique. Therefore, the calculation result shown in FIG. 2 is obtained by connecting the operating points having the same engine efficiency P in a contour line with the rotational speed of the engine 20 as the horizontal axis and the torque of the engine 20 as the vertical axis, as shown in FIG. An efficiency curve of efficiency P can be drawn.

  The operating point determination unit 14 is a part that determines the operating point of the engine 20, that is, the rotational speed and torque of the engine 20, in response to the traveling state of the vehicle and the request from the user.

  As shown in FIG. 1, the operating point determination unit 14 includes, for example, an engine speed sensor 70, a torque sensor 71, a vehicle speed sensor 72, an engine ECU and a BCU 73 (battery control unit), a voltage sensor 74 for the electric heater 50, and various types. A temperature sensor 75 or the like is connected. The operating point determination unit 14 determines the operating point of the engine 20 based on the traveling state of the vehicle input from these sensors and the control unit. The various temperature sensors 75 are, for example, an outside air temperature sensor, a cooling water temperature sensor, and a vehicle interior temperature sensor.

  The required engine output E and engine efficiency P vary depending on the vehicle running conditions and user requests. Therefore, the operating point determination unit 14 determines the operating point of the engine 20 so that the required engine output E and engine efficiency P can be handled.

  Of the engine output, the driving energy Ea for running the vehicle is calculated from the required torque and the vehicle speed. The energy Eb used for charging the battery 40 is calculated in accordance with a charge request from the BCU based on the charge state or discharge rate of the battery 40. In this embodiment, for simplification of explanation, explanation will be made assuming that Ea and Eb are constant.

  The sum Ec + Ed of the heater power Ec and the heat output Ed corresponds to the heating energy. The heating energy is calculated by the heating energy calculation unit 15 based on, for example, the outside air temperature, solar radiation, vehicle speed, vehicle interior temperature, and vehicle interior set temperature.

  Next, with reference to FIG. 4 and FIG. 5, the specific operation | movement of the vehicle control apparatus 10 which concerns on this embodiment is demonstrated. FIG. 4 is an operation flowchart of the vehicle control device 10. FIG. 5 is a conceptual diagram when determining the operating point of the engine 20.

  As shown in FIG. 4, step S10 is first executed. Step S <b> 10 is a step in which the engine efficiency calculation unit 13 calculates the engine efficiency P based on information stored in the shaft output database 11 and the heat output database 12. As shown in FIG. 2, the engine efficiency P is output in a form corresponding to each energy Ea, Eb, Ec, Ed constituting the engine output E and the fuel consumption F for realizing the energy distribution. . Note that the engine efficiency P may be stored as a database by the vehicle control device 10 in advance.

  Next, step S11 is executed. Step S11 is a step in which the operating point determination unit 14 calculates drive energy Ea that is used for traveling of the vehicle. The operating point determination unit 14 calculates Ea based on the running state of the vehicle and the torque and vehicle speed requested by the user. In addition, it is good also as a structure where the operating point determination part 14 acquires what was calculated outside the vehicle control apparatus 10. FIG.

  Next, step S12 is executed. Step S <b> 12 is a step in which the operating point determination unit 14 calculates the energy Eb used for charging the battery 40. The operating point determination unit 14 calculates Eb in accordance with a charging request from the BCU based on the charging state or discharging speed of the battery 40.

  Next, step S13 is executed. Step S13 is a step in which the heating energy calculation unit 15 calculates the heating energy Ec + Ed. The heating energy calculation unit 15 calculates necessary heating energy based on, for example, outside air temperature, solar radiation, vehicle speed, vehicle interior temperature, and vehicle interior set temperature.

  Next, step S14 is executed. Step S14 is a step in which the operating point determination unit 14 calculates the required engine output E. The operating point determination unit 14 calculates a required engine output E (= Ea + Eb + Ec + Ed) from the driving energy Ea calculated in steps S10 to S13, the energy Eb used for charging, and the heating energy Ec + Ed.

  Next, step S15 is executed. Step S <b> 15 is a step in which the operating point determination unit 14 specifically determines the operating point of the engine 20. This will be described in more detail below.

  First, it is assumed that the driving state of the engine 20 is the state A shown in FIG. In the state in which the state A is realized, it is assumed that the engine 20 is driven at the rotation speed and torque as indicated by the point A in FIG. An example will be described in which the user raises the vehicle interior set temperature in the state A.

  If there is a vehicle interior temperature rise request from the user, the value of the heating energy calculated in step S <b> 13 is larger than that in state A. For example, as shown in FIG. 2, if the heating energy Ec + Ed is 5 kw in the state A, and the heating energy becomes 10 kw due to a request to increase the passenger compartment temperature, the operating point candidate is the state in FIG. 2. C and state D exist. In the present embodiment, since Ea and Eb are assumed to be constant, the engine output is increased from 20 kw to 25 kw.

  Incidentally, the engine efficiency calculation unit 13 can draw an equal output curve in which the engine output is constant on the equal efficiency curve as shown in FIG. 3 based on the calculation result as shown in FIG. FIG. 5 illustrates an equal output curve when the engine output is 25 kw. State C and state D always exist on this iso-output curve.

  The operating point determination unit 14 determines, as an operating point, an intersection point with a curve having the maximum engine efficiency among the isoefficiency curves intersecting with the 25 kw iso-output curve. In this example, as shown in FIG. 5, the maximum iso-efficiency curve intersecting with the 25 kw iso-output curve is a 45% curve, and the intersection (point C shown in FIG. 5) is, for example, the state C shown in FIG. It is. The operating point determination unit 14 selects the state C as the operating point of the engine 20 that satisfies the user's request. That is, the energy distribution between the heater power Ec and the heat output Ed applied as the power of the electric heater 50 is a state in which the engine efficiency P is higher in the state C than in the state D.

  Next, step S16 is executed. Step S <b> 16 is a step in which the vehicle control device 10 calculates the drive amount of the electric heater 50. The driving amount of the electric heater 50 is obtained by multiplying the heater power Ec in the engine output E by the power generation efficiency of the generator 30. The amount of energy ΔEc to the electric heater 50 to be increased or decreased when shifting from the state A to the state C is a difference between the shaft output in the state C and the shaft output in the state A. Therefore, the vehicle control device 10 calculates the driving amount of the electric heater 50 as a value obtained by multiplying ΔEc by the power generation efficiency.

  Next, step S17 is executed. Step S <b> 17 is a step in which the vehicle control device 10 instructs the engine 20, the generator 30 and the electric heater 50 to drive so that the engine output is distributed with energy corresponding to the operating point.

  Next, the effect of the vehicle control apparatus 10 according to the present embodiment will be described.

  The vehicle control apparatus 10 in the present embodiment takes into account the thermal output Ed in the calculation of the engine efficiency P. For this reason, it is possible to select an operating point at which the fuel efficiency is more optimal as compared with the conventional configuration in which the operating point of the engine is determined using engine efficiency that takes into account only the shaft output.

  Moreover, this vehicle control apparatus 10 determines the heating energy required in step S13, and determines the engine output to a fixed value in step S14. In subsequent step S15, the heater power Ec and the heat output Ed that are allocated as the power of the electric heater 50 are appropriately distributed so that the engine efficiency P is maximized. For this reason, the engine efficiency can be maximized while securing sufficient energy for heating. In particular, for determining the operating point of the engine 20, it is preferable to use an equal efficiency curve and an equal output curve as shown in FIG.

(Second Embodiment)
In 1st Embodiment, before determining the operating point of the engine 20, the vehicle control apparatus 10 showed about the example which has the heating energy calculation part 15 which sets heating energy to a fixed value. On the other hand, in this embodiment, as shown in FIG. 6, the vehicle control device 10 has a target efficiency calculation unit 16. Since the configuration of the vehicle control device 10 excluding the target efficiency calculation unit 16 is the same as that of the first embodiment, the description thereof is omitted.

  Prior to determining the operating point of the engine 20, the target efficiency calculation unit 16 determines a target engine efficiency P. The target efficiency calculation unit 16 sets the value of the engine efficiency to a predetermined value based on, for example, the outside air temperature, solar radiation, vehicle speed, vehicle interior temperature, and vehicle interior set temperature. Specifically, the target efficiency calculation unit 16, for example, in the case where the cooling water of the engine 20 has not reached a predetermined threshold value, the target efficiency is calculated so as to reduce the efficiency compared to the case where the cooling water has reached the threshold value. The engine efficiency P is defined as follows. Alternatively, the target efficiency calculation unit 16 may, for example, set the target efficiency so as to reduce the efficiency when the temperature in the vehicle interior does not reach a predetermined set temperature, compared to when the temperature in the vehicle interior reaches the set temperature. The engine efficiency P is defined as follows.

  Next, a specific operation of the vehicle control device 10 according to the present embodiment will be described with reference to FIGS. FIG. 7 is an operation flowchart of the vehicle control device 10. FIG. 8 is a conceptual diagram when determining the operating point of the engine 20.

  As shown in FIG. 7, first, step S20 to step S22 are executed in order. Steps S20 to S22 are the same as steps S10 to S12 in the first embodiment, and thus detailed description thereof is omitted.

  Next, step S23 is executed. Step S23 is a step in which the operating point determination unit 14 calculates a value obtained by removing heating energy from the required engine output E. That is, the operating point determination unit 14 calculates an output Ea + Eb from the driving energy Ea calculated in steps S21 and S22 and the energy Eb used for charging.

  Next, step S24 is executed. Step S24 is a step in which the target efficiency calculation unit 16 determines the target engine efficiency P. As described above, the target value of engine efficiency is determined based on, for example, the outside air temperature, solar radiation, vehicle speed, vehicle interior temperature, and vehicle interior set temperature. This will be described in more detail below.

  First, it is assumed that the driving state of the engine 20 is the state A shown in FIG. In the state in which the state A is realized, it is assumed that the engine 20 is driven at the rotation speed and torque as indicated by the point A in FIG. In the state A, the case where the temperature in the passenger compartment becomes higher than the set temperature set by the user will be described as an example.

  In the state where the temperature in the passenger compartment is higher than the set temperature, priority can be given to engine efficiency over heating. For this reason, the target efficiency calculation unit 16 sets the engine efficiency higher than the engine efficiency (P = 40%) in the state A as the target efficiency. For example, P = 45% is set.

  Next, step S25 is executed. Step S <b> 25 is a step in which the operating point determination unit 14 specifically determines the operating point of the engine 20. State C and state E in FIG. 2 exist as candidate operating points at which the engine efficiency P is 45%. The operating point determination unit 14 in this embodiment determines the operating point on the equiefficiency curve so that the engine output E is minimized. Therefore, the operating point determination unit 14 selects the state C as the operating point of the engine 20. That is, the energy distribution between the heater power Ec and the heat output Ed applied as the power of the electric heater 50 is a state where the engine output is smaller in the state C than in the state E.

  Next, step S26 and step S27 are executed. Since step S26 and step S27 are the same as step S16 and step S17 in the first embodiment, detailed description thereof is omitted.

  Next, the effect of the vehicle control apparatus 10 according to the present embodiment will be described.

  The vehicle control apparatus 10 in this embodiment determines the target engine efficiency P in step S24. In subsequent step S25, the heater power Ec and the heat output Ed, which are allocated as the power of the electric heater 50, are appropriately distributed so that the engine output is minimized. For this reason, the engine output P can be minimized, that is, the fuel consumption F can be suppressed while the target engine efficiency P is maintained.

(Other embodiments)
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the calculation of the engine efficiency P in each of the above-described embodiments, that is, in step S10 in FIG. 4 and step S20 in FIG. 7, the engine efficiency P is preferably calculated in consideration of the power generation efficiency of the generator 30. .

  In this configuration, as shown in FIG. 9, the engine efficiency calculation unit 13 includes a power generation efficiency acquisition unit 17. The power generation efficiency acquisition unit 17 acquires the power generation efficiency of the power generator 30 that varies depending on the traveling conditions in real time. The engine efficiency calculation unit 13 calculates the engine efficiency P while correcting the energy Eb used for charging the battery 40 and the heater power Ec based on the power generation efficiency acquired by the power generation efficiency acquisition unit 17. As a result, the engine efficiency P can be calculated in consideration of the power generation efficiency depending on the driving conditions, and therefore the optimum engine operating point can be determined more accurately.

  In 1st Embodiment, the vehicle control apparatus 10 showed the structure which has the heating energy calculation part 15. FIG. Moreover, in 2nd Embodiment, the vehicle control apparatus 10 showed the structure which has the target efficiency calculation part 16. As shown in FIG. However, the vehicle control device 10 may include both the heating energy calculation unit 15 and the target efficiency calculation unit 16. In this case, the user may select one of whether to give priority to the engine efficiency P or the engine output, or the vehicle control device 10 automatically selects according to the traveling state of the vehicle. You may make it choose.

DESCRIPTION OF SYMBOLS 10 ... Vehicle control apparatus, 11 ... Axis output database, 12 ... Thermal output database, 13 ... Engine efficiency calculation part, 14 ... Operating point determination part 20 ... Engine 30 ... Generator 40 ... Battery 50 ... Electric heater

Claims (6)

A vehicle control device that heats and heats an electric heater (50) according to a driving situation of an engine (20),
Engine efficiency calculated from the engine output (E), which is the sum of the shaft output, which is the output for vehicle travel and power generation, and the heat output for heating the cooling water, and the fuel consumption (F) ( Engine efficiency calculation unit (13) for calculating (P);
An operating point determination unit (14) for determining an operating point of the engine,
The operating point determination unit,
Determining the operating point corresponding to the required engine output based on the engine efficiency (P) calculated by the engine efficiency calculation unit based on the shaft output database (11) and the heat output database (12);
Based on the shaft output (Ea + Eb + Ec) corresponding to the operating point, driving energy (Ea) used for traveling, energy (Eb) used for charging, and heating energy (Ec + Ed) required for heating the heating energy, the axis heater power (Ec) that is contained appropriated as the power of the electric heater to the output, the thermal output (Ed) and the vehicle control device comprising a Turkey be distributed. A heating energy calculation unit (15) for calculating the heating energy according to the driving state of the engine;
The operating point determination unit converts the heating energy into the heater power and the heat output so that the engine efficiency is maximized under a condition in which the heating energy becomes a constant value determined by the heating energy calculation unit. The vehicle control device according to claim 1, wherein the operating point is determined by allocating to each other.   The operating point determination unit determines, as the operating point, an intersection between an iso-output curve where the engine output is constant at a predetermined value and an iso-efficiency curve expressing the engine efficiency in a contour line. The vehicle control device according to claim 2. A target efficiency calculation unit (16) for calculating a predetermined value for the engine efficiency based on an environmental condition in a vehicle compartment;
The operating point determination unit converts the heating energy into the heater power and the heat output so that the engine output is minimized under a condition in which the engine efficiency is a constant value determined by the target efficiency calculation unit. The vehicle control device according to claim 1, wherein the operating point is determined by allocating to each other. When the temperature of the cooling water has not reached a predetermined threshold, or the temperature in the passenger compartment has not reached a predetermined set temperature,
The target efficiency calculation unit sets the target engine efficiency to be smaller than that when the temperature of the cooling water reaches a predetermined threshold and the temperature of the passenger compartment reaches a predetermined set temperature. The vehicle control device according to claim 4, wherein:   The engine efficiency calculation unit includes a power generation efficiency acquisition unit (17) that acquires the power generation efficiency of a generator mounted on a vehicle, and sequentially recalculates the shaft output in the engine output based on the power generation efficiency. The vehicle control device according to claim 1, wherein the engine efficiency is calculated.

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