JP2002081331A - Moving body having hybrid driving source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operation efficiency of a hybrid vehicle having a fuel cell and a heat engine. SOLUTION: This hybrid vehicle uses as a power source a motor 20 driven by the fuel cell 54 as an electric source and an engine 10. Operation efficiencies of the fuel cell and the engine in response to an operation state are calculated, and one having higher operation efficiency is used as a driving source. Thus, the operation efficiency of the vehicle can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body which moves by using two driving sources.

[0002]

2. Description of the Related Art In recent years, there has been proposed a vehicle that runs on a motor driven by a fuel cell. A fuel cell refers to a device that generates power by an electrochemical reaction between hydrogen and oxygen.
What is discharged from the fuel cell is mainly water vapor, which does not contain harmful components, and thus has the advantage of being very environmentally friendly.

[0003] In addition to fuel cells, vehicles using a heat engine as a driving source have been proposed. Such a vehicle has an advantage that by providing two types of driving sources having different characteristics, it is possible to realize an efficient driving by combining the advantages of both types.

[0004]

Conventionally, in a vehicle having a fuel cell and a heat engine, the fuel cell is conventionally used only for charging the battery or as an assist source for the heat engine at a high load. Did not. Although the operating efficiency of the fuel cell and the heat engine varies depending on the operating conditions, the two have not been properly used in consideration of such changes. Therefore, there is room for improvement from the viewpoint of improving operation efficiency. At this time, not only from the viewpoint of energy efficiency, it has been desired to realize various efficiency improvements such as emission of emissions.

[0005] The present invention relates to a fuel cell and a heat engine.
An object of the present invention is to improve the operating efficiency of a moving body having the above-described driving source by selectively using both.

[0006]

Means for Solving the Problems and Actions and Effects Thereof To solve at least a part of the above problems, the present invention provides:
The following configuration was adopted. The moving body of the present invention has a first drive source having a first relationship between the operating state and efficiency of the moving body, and a second relationship between the operating state and efficiency of the moving body. A second driving source, an operating state detecting means for detecting an operating state of the moving body, and an efficiency comparison between the first driving source and the second driving source according to the detected operating state. The gist of the present invention is to include a control unit that performs driving using the driving source. The moving object here includes, for example, a vehicle, an aircraft, and a ship.

The operating state detecting means is means for detecting various parameters indicating the operating state of the moving body. The parameters include, for example, moving speed, required torque, remaining fuel of the drive source, temperature, and the like.

In the moving body of the present invention, the driving source is selected based on the efficiency comparison of the driving sources, so that the efficiency of the moving body can be improved.

The control means prepares a map in which the driving sources are specified after comparing the operating efficiencies of the first and second driving sources in advance for each operating state, and performs the above-mentioned selection by referring to the maps. Is also good. In addition, it is also possible to determine the operation efficiency of both of them and use them separately.

[0010] In the latter aspect, for example, the control means includes:
A first efficiency specifying unit that obtains a first efficiency when driving is performed using the first driving source based on the operating state; and a second efficiency determining unit that uses the second driving source based on the operating state. Efficiency specifying means for obtaining the efficiency in the case of performing the driving by using the driving control means for performing driving by using the output of the higher efficiency side among the first and second driving sources. Is achieved.

In the case where the efficiency specifying means is provided, a first storage means for storing the first relation and a second storage means for storing the second relation are provided. It is preferable that the specifying means and the second efficiency specifying means obtain the efficiency by referring to the first storage means and the second storage means, respectively. In the storage means,
The relationship between a predetermined parameter representing the operating state and the efficiency,
What is necessary is just to store in advance in the form of a function, a table, or the like.

In the moving body according to the present invention, when at least one of the first relation and the second relation is a relation that fluctuates in accordance with an operation state of each drive source, the control means controls the drive unit. It is desirable to perform the efficiency comparison in consideration of the operating state of the source. The efficiency of the drive source may fluctuate depending on temperature and other operating conditions. In such a case, the efficiency comparison can be performed more accurately by considering the operation state. For example, it can be easily realized by storing a plurality of relationships in the first or second storage means, including parameters relating to the operating state. As another method, after the efficiency is calculated assuming a standard operation state, a correction according to the operation state may be performed.

In the moving body of the present invention, for example, the first drive source may be a heat engine, and the second drive source may be an electric motor powered by a fuel cell.

It is known that the efficiency of a heat engine fluctuates according to the number of revolutions, torque and temperature. When a heat engine is used as the drive source, it is desirable that the relationship between these parameters and the efficiency be stored in the first storage means in advance in the form of a function, a table, or the like. Further, the efficiency specifying means for the heat engine includes, for example, means for obtaining the efficiency in consideration of at least the engine efficiency of the heat engine, means for obtaining the efficiency in consideration of at least the fuel efficiency, and in consideration of at least the engine efficiency and the fuel efficiency. It can be constructed in a mode such as a means for obtaining efficiency.

The efficiency of the fuel cell includes the efficiency of the electric motor in addition to the efficiency of the fuel cell itself. The efficiency specifying means for the fuel cell stores in advance the relationship between the efficiency and the parameters such as the output required for the fuel cell, the number of revolutions of the electric motor, and the torque, and specifies the operating efficiency by referring to this. Further, the efficiency specifying means for the fuel cell includes, for example, means for specifying the efficiency in consideration of at least the system temperature of the fuel cell, means for specifying the efficiency in consideration of at least the amount of power generation, and at least the time elapsed since the start. Means for specifying the efficiency by taking into account, means for specifying the efficiency by taking into account at least a predetermined parameter value related to the degree of deterioration of the fuel cell, and means for specifying the efficiency by taking a combination thereof into various forms such as Can be built. Here, the system temperature may include the temperature of the reformer and the like in addition to the temperature of the fuel cell itself.

In the moving body of the present invention, for example, the efficiency can be represented by using at least one of energy efficiency, economic efficiency, and emission control efficiency. Each efficiency can be improved by the efficiency focused on when the drive source is properly used.

Energy efficiency refers to the ratio between the ideal energy that can be output per unit fuel and the energy that is actually output. The higher the energy efficiency, the less fuel is consumed. Energy efficiency can also be represented by the reciprocal of the fuel consumed for the output of the unit driving force. Therefore, fuel consumption can be suppressed by considering the energy efficiency when using the drive source properly.

The economic efficiency corresponds to the reciprocal of the output price per unit driving force. It is determined by the amount of fuel consumed at the time of driving force output and the fuel unit price. For example, even for a drive source with high energy efficiency and low fuel consumption, if the fuel unit price is high, the economic efficiency may be low. Therefore, the economic burden on the user can be reduced by considering the economic efficiency.

When the economic efficiency is specified, it is necessary to input a fuel unit price. Therefore, it is desirable that the moving body be provided with an interface for inputting the fuel unit price. For example, a touch panel or the like for the driver to input can be used. Further, means for acquiring the fuel unit price by external wireless communication may be provided.

The emission suppression efficiency corresponds to the reciprocal of the amount of emission discharged at the time of output of the unit driving force, that is, the so-called emission amount. The smaller the emission, the higher the emission control efficiency. Therefore, environmentally friendly operation can be realized by considering the emission control efficiency when using different drive sources. Here, the amount of emission is illustrated, but noise emitted from the moving object may be used as a parameter.

In the moving body according to the present invention, the control means may perform the driving by comparing a plurality of types of the efficiencies with respect to the first and second driving sources.

By doing so, it is possible to selectively use the driving sources in consideration of a plurality of efficiencies comprehensively. As an example, the three types of energy efficiency, economic efficiency, and emission control efficiency exemplified above can be considered. By setting weights for these efficiencies in advance, it is possible to realize the proper use of the drive sources that maximize the three types of efficiencies comprehensively.

When considering a plurality of efficiencies, the control means may consider the plurality of efficiencies according to a predetermined priority. The priority may be changed according to the driving state of the moving object.

[0024] The driver may be provided with setting means capable of setting whether or not to consider at least part of the plurality of types of efficiency in the control or the priority.

By considering the priority order and giving the driver a degree of freedom in setting, it is possible to selectively use the driving source according to the actual circumstances such as the environment during driving and the driver's intention. .

[0026] In the moving body of the present invention, a first usability judging means for judging the usability of the first drive source;
A second use determination unit for determining whether the second drive source is usable, wherein the control unit includes the first and second drive sources.
It is preferable that the control unit executes the control only when it is determined that both of the drive sources are in a usable state. By doing so, it is possible to reduce the burden of calculating the operation efficiency.

The availability can be determined on the basis of the presence / absence of a failure in the heat engine and the fuel cell, the warm-up state, the remaining fuel, and the like. The state corresponding to “use or non-use” does not necessarily need to be limited to the case where the heat engine and the fuel cell cannot be operated at all. An arbitrary state set as one that should be restricted from being used as a driving source corresponds to the state. For example, it may be determined that the fuel cell is not used when the remaining fuel of the fuel cell becomes less than a certain value. At this time, the fuel cell is determined to be “use prohibited” in the control of the present invention, but there is a possibility that the fuel cell will be used in other controls. For example, the availability may be determined based on not only the state of the fuel cell but also the state of the electric motor driven by the power supply from the fuel cell. From these viewpoints, the second usability judging means is, for example, a means for judging the usability by considering at least the output rating of an electric motor driven by using the fuel cell as a power supply, and is used by considering at least the power generation rating of the fuel cell. It can be constructed in various modes, such as means for judging permission or means for judging permission by combining these.

In the moving body according to the present invention, the first drive source is a heat engine, the second drive source is a motor driven by a fuel cell, and an alternative power source for the fuel cell. And a storage efficiency specifying means for obtaining an operating efficiency based on the operation state when the fuel cell is driven by using the output of the storage, wherein the control means is provided when the fuel cell is in an unusable state. According to the present invention, the heat engine and the storage device may be driven by using the output of the higher operation efficiency side. The storage device includes a secondary battery, a capacitor, and the like.

This is an embodiment in which two types of power sources, that is, a fuel cell and a battery are used preferentially over the battery and the drive source for the electric motor and the heat engine is selectively used. The capacitor not only has a loss when discharging power,
It is normal to have some loss during charging. Therefore, by giving priority to fuel cells over capacitors,
Efficiency can be improved. In a state where the fuel cell is unusable, efficient operation can be realized according to the situation by comparing the efficiency between the electric storage device and the heat engine. The storage efficiency specifying means may be configured, for example, in such a manner that the relationship between the operating state and the efficiency is stored in advance. The operating efficiency when using a battery can be obtained by converting the power consumption to the efficiency when charging by a heat engine.

In the present invention, an energy output source, that is, a suppression means for suppressing frequent switching of the use state of the heat engine, the fuel cell, and the battery can be applied to the control means. For example, the suppression unit is a unit that suppresses the switching while the predetermined condition is not satisfied after the switching of the energy output source. As the condition at this time, an elapsed period after the switching, a traveling distance after the switching, an operation state of the operation unit after the switching, and the like can be applied. As the operation state of the operation unit, for example, that the shift position of the transmission becomes neutral can be applied.

In the present invention, for example, in a predetermined traveling state, control using any one of the energy output sources may be applied regardless of the efficiency comparison.

The present invention can be configured in various modes other than the above-described moving body, such as a control method for the moving body, a control method for selectively using a driving source, and the like.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention applied to a hybrid vehicle will be described in the following sections. A. Device configuration: General operation: Operation control:

A. FIG. 1 is a schematic configuration diagram of a hybrid vehicle as an embodiment. The power sources of the hybrid vehicle of this embodiment are the engine 10 and the motor 20. As illustrated, the power system of the hybrid vehicle according to the present embodiment includes an engine 10, an input clutch 18,
Motor 20, torque converter 30, and transmission 10
0 are connected in series. The output shaft 15 of the transmission 100 is connected to the axle 1 via a differential gear 16.
7. The input clutch 18 is connected to the engine 1
0 is a mechanism for intermittently transmitting power between the crankshaft 12 and the motor 20.

The engine 10 can use various heat engines. In this embodiment, a normal gasoline engine was used. As the motor 20, any of a DC motor and an AC motor can be applied. In this embodiment, a three-phase synchronous motor is used. The motor 20 is rotated by the three-phase AC generated by the drive circuit 52 configured as a transistor inverter. As a power source for the motor 20, a battery 50 and a fuel cell 54 are provided. The main power source is the fuel cell 54, and the battery 50 is used as a power source for compensating for the insufficient power generation of the fuel cell 54. The power of the battery 50 is mainly supplied to the control unit 70 and power devices such as lighting devices. The fuel cell 54 is a device that generates power by an electrochemical reaction between hydrogen and oxygen, and various types can be applied. In this embodiment, a solid polymer type is used. The hydrogen supplied to the fuel cell 54 may be stored directly, or may be generated by reforming a predetermined raw material. In this embodiment, the fuel tank FC for the fuel cell 54 is
To produce hydrogen by reforming the methanol stored in the furnace. As a raw material for reforming, hydrocarbon compounds such as natural gas and gasoline, methanol and other alcohols, aldehydes and the like can be used.

The torque converter 30 is a so-called fluid coupling. As the transmission 100, a stepped transmission having five forward steps and one reverse step was used. Switching of the shift speed of the transmission 100 is realized by the hydraulic control unit 104 switching the hydraulic system from the pump 102 to the transmission 100. The shift range of the gear can be adjusted by the driver operating the shift lever. The shift lever can select any of parking (P), reverse (R), neutral (N), drive position (D), and 4 to L positions. The shift speed is set in a range set in advance according to each shift position.

In addition to the power transmission system to the axle 17, an auxiliary drive 82 is connected to the engine 10. The auxiliary equipment includes a compressor for an air conditioner, a pump for power steering, a pump for cooling the fuel cell 54, and the like. Here, the accessories driven using the power of the engine 10 are collectively shown as an accessory drive 82. The accessory drive device 82 is specifically connected via a belt to a pulley provided on the crankshaft of the engine 10 via the accessory clutch 19, and is driven by the rotational power of the crankshaft.

An accessory driving motor 80 is also connected to the accessory driving device 82. As the accessory driving motor 80, any of a DC motor and an AC motor can be applied. In this embodiment, a three-phase synchronous motor is used. The auxiliary drive motor 80 is
Drive circuit 56 configured as a transistor inverter
, And is rotated by the three-phase AC generated using the battery 50 and the fuel cell 54 as power sources. When the operation of the engine 10 is stopped, the accessory driving device 82 can be driven by the accessory driving motor 80. At this time, the clutch 19 is released to reduce the load. The accessory drive motor 80 also functions as a generator that generates power by the power of the engine 10. The electric power thus generated can charge the battery 50.

Between the driving circuits 52 and 56 and each power supply,
A changeover switch 51 capable of switching the connection state to three positions,
55 are provided. By the operation of the changeover switch 55, the fuel cell 54 is connected to the drive circuit 56 (circuit a in the figure), connected to the drive circuit 52 (circuit b in the figure), and connected to the battery 50. It is possible to realize three types of connection states (circuit c in the figure).
Similarly, the operation of the changeover switch 51 causes the battery 50
Indicates the selection of the drive circuit 56, the drive circuit 52, the fuel cell 5
4 can be switched.

The operation of each unit described above is controlled by the control unit 70. The control unit has a CP inside
It is configured as a microcomputer having a U, a memory, and the like. Various signals necessary for performing the control are input to the control unit 70. The input signal includes, for example, a signal from an operation state sensor 73 that detects each operation state of an operation unit 74 such as an accelerator pedal, a brake pedal, a shift lever, and a parking brake, and a gasoline remaining amount in a fuel tank EG for the engine 10. The remaining amount sensor 75 for detecting the amount, the FC of the fuel tank FC for the fuel cell 54
A remaining amount sensor 76 for detecting the remaining amount of fuel, a vehicle speed sensor 78, and the like are included. Signals from other various sensors are input to the control unit 70, but are not shown here.

The control unit 70 has various functional blocks for realizing control. FIG. 1 shows an efficiency calculator 71 and a drive controller 72 as functional blocks characteristic of the present embodiment. The efficiency calculation unit 71
The energy efficiency of the power source in the operating state is calculated based on the required torque and the vehicle speed determined based on the state of the operation unit 74. The efficiency calculation unit 71 calculates the energy efficiency of the engine 10, the energy efficiency when driving the motor 20 using the fuel cell 54 as a power supply, and the energy efficiency when driving the motor 20 using the battery 50 as a power supply. The drive control unit 72 compares the calculated energy efficiencies and uses power sources properly. Control processing realized by these functional blocks will be described later in detail.
In this embodiment, these functional blocks are configured by software, but may be configured by hardware.

B. General operation: The hybrid vehicle of the present embodiment travels by using two power sources, that is, the engine 10 and the motor 20, according to the vehicle speed and the torque. The proper use of the two is set in advance as a map and stored in the ROM in the control unit 70.

FIG. 2 is an explanatory diagram showing the relationship between the running state of the vehicle and the power source. The area MG in the figure is an area in which the motor 20 and the engine 10 are used separately for traveling. Area MG
, Ie, the EG region is a region where the vehicle runs with the engine 10 as a power source. Although the vehicle of the present embodiment can run using both the engine 10 and the motor 20 as power sources, such an operation mode is basically not used.

When the motor 20 is selected as the power source in the MG range, the hybrid vehicle starts with the power of the motor 20 with the input clutch 18 turned off. When the vehicle speed and the accelerator opening reach the running state near the boundary between the area MG and the area EG, the control unit 70
8 is turned on and the engine 10 is started. Thereafter, the vehicle runs using only the engine 10 as a power source. While the engine is running, the motor 20 simply turns idle. Judgment regarding the proper use of power sources in the MG area
Often done. Therefore, the power source may be switched from the motor 20 to the engine 10 or vice versa in the MG region. Note that, for example, the motor 20 may always be used as a power source in a specific region, such as a region A in the map shown in FIG. Control without such a region is also possible.

The control unit 70 controls the switching of the gear stage as well as the proper use of the power source. The shift speed is switched based on a map set in advance in the running state of the vehicle. FIG. 2 shows a map at the D position. As shown in the figure, the control unit 70 switches the gear so that the gear ratio decreases as the vehicle speed increases.

C. Operation control: The proper use of the power source in the MG area is realized by the following control processing. FIG. 3 is a flowchart of a drive control processing routine. When the vehicle speed and the required torque are in the MG region (see FIG. 2), the CPU in the control unit 70 repeatedly executes the process together with other control processes.

The CPU switches the control contents in the following four ways according to the remaining FC fuel and the remaining gasoline. If the FC fuel level is sufficient (step S10) and the gasoline level is insufficient (step S12), the fuel cell 54
The vehicle is driven by driving the motor 20 using the power as a power source (step S18). The determination as to whether the FC fuel remaining amount and the gasoline remaining amount are sufficient or insufficient is made according to the magnitude relationship between a predetermined value provided for each fuel and the remaining amount.

When it is determined that both the FC fuel remaining amount and the gasoline remaining amount are sufficient (steps S10 and S12),
The fuel cell 54 and the engine 10 are selectively used based on the operation efficiency. The CPU operates the motor 20 with the fuel cell 54.
Is calculated, and the operating efficiency ηe when driven by the engine 10 is calculated (step S
14), select the side with higher operation efficiency as the power source. That is, when “ηe> ηf”, the vehicle runs using the engine 10 as a power source (steps S16 and S20). In other cases, the vehicle runs using the motor 20 powered by the fuel cell 54 as a power source (step S16). , S18).

Here, a method of calculating the operating efficiencies ηe and ηf will be described. In general, the operating efficiency varies depending on various parameters such as a vehicle speed, a required torque, and a temperature of each unit. Further, it is necessary to consider a loss when transmitting the output power to the axle 17. In the present embodiment, the influence on the operation efficiency (hereinafter, referred to as “element efficiency”) is obtained in advance for each of several elements related to the output of the power, and the total efficiency is calculated by multiplying them. .

Specifically, the operating efficiency ηe when the engine 10 is used as a power source is given by the following equation. ηe = ηeng × ηm × ηg; each element efficiency ηeng, η
The contents of m and ηg are as follows. ηeng
(0 <ηeng <1.0 real number) indicates the energy efficiency of the engine 10 as a heat engine, and the power that the engine 10 can output in each operating state from a unit volume of fuel;
It shows the ratio with the power that can be output in the most efficient state. That is, it is a value indicating the effect of the difference in the operation state on the operation efficiency.

Ηm (real number of 0 <ηm <1.0) is the power transmission efficiency in the power transmission system including the torque converter 30, the transmission 100, the differential gear 16, and the like, that is, the power transmitted to the axle 17 Engine 10
This is the ratio with the power output from the.

Ηg (a real number of 0 <ηg <1.0) represents gasoline efficiency, which is the difference between the energy that the engine 10 can actually extract from gasoline per unit volume and the energy that can be extracted in an ideal state. Ratio.

The operating efficiency ηf when the motor 20 is driven by the fuel cell 54 is given by the following equation. ηf = ηmot × ηm × ηL × ηa; each element efficiency ηmo
The contents of t, ηm, ηL, and ηa are as follows, respectively. η mot (real number of 0 <η mot <1.0) is the operating efficiency of the electric motor. That is, it is the ratio between the power output from the motor 20 and the power consumption. The value fluctuates according to the temperature, rotation speed, and torque of the motor 20.

Ηm (0 <ηm <1.0 real number) is the power transmission efficiency already described. In the present embodiment, the power transmission efficiencies of the engine 10 and the motor 20 can be regarded as substantially equal, but depending on the configuration, a value different from that used when calculating the operating efficiency ηe can be used.

ΗL (real number of 0 <ηL <1.0) is expressed by FC
Fuel efficiency. FC per unit volume
This is the ratio between the power actually output from the fuel and the power that can be output in an ideal operating state.

Ηa (real number of 0 <ηa <1.0) is the power generation efficiency of the fuel cell 54. This is the ratio of the power that the fuel cell 54 can actually output in each operating state to the power that can be output in the ideal operating state. The value changes according to the temperature of the fuel cell 54, the power generation amount, the elapsed time from the start, the degree of deterioration of the fuel cell, and the like. Generally, the power generation efficiency decreases as the temperature decreases. If the rating of the fuel cell 54 is too small or too large, the power generation efficiency will decrease. If the warm-up immediately after the start of the engine is not sufficiently completed, the power generation efficiency is low. A fuel cell that has been used for a long period of time has reduced performance and reduced power generation efficiency. The power generation efficiency ηa is set based on a function or a map prepared in advance according to these parameters.

The element efficiencies used for calculating the operating efficiencies ηe and ηf are prepared in advance as a map or a function according to parameters representing the operating state such as the number of revolutions, torque, engine water temperature, fuel cell temperature, etc. Is stored in the memory. The CPU calculates each element efficiency with reference to the map and the like, and calculates the operating efficiencies ηe, η
f can be obtained. Note that the calculation of the operating efficiency ηe using the above equation is merely an example, and it is possible to consider more elemental efficiencies, or a map or a function that directly gives the operating efficiency ηe, ηf from the parameters representing the operating state. May be prepared.

FIG. 4 is an explanatory view exemplifying a map for giving the driving efficiency. For convenience of explanation, a simplified map is shown. Curves CE1 to CE3 are maps that give the operating efficiency ηe of the engine 10. The operating efficiency ηe changes according to the power. Actually, even if the power is the same, the operating efficiency changes if the rotation speed and the torque change. Further, it also varies depending on the operating temperature, such as the water temperature of the engine 10, the operation of the supercharger, and the difference in the air-fuel ratio between the lean state and the stoichiometric state. In accordance with these operating conditions, a curve CE1 in FIG.
A plurality of maps for providing the driving efficiency as shown by CE3 are prepared. In the following description, it is assumed that the operating state of the engine 10 corresponds to the curve CE2.

Curves C1 to C3 are maps giving the operating efficiency ηf of the fuel cell 54. A three-step curve is illustrated according to the temperature of the fuel cell 54. In practice, a curve will be drawn according to more parameters. The efficiency varies depending on the required load, that is, the power. The operating efficiency of the fuel cell 54 is drawn in a load range that is equal to or less than a predetermined value because the operating range is limited to this range. It is. Such a map is set in advance experimentally or analytically.

According to this map, when the temperature of the fuel cell 54 corresponds to the curve C1, the operating efficiency of the fuel cell 54 is higher in a region where the load is lower than the value a, and the engine 10 is in a region where the load is lower than the value a. Operating efficiency is higher. When the temperature corresponds to the curve C2, the value b,
In the case corresponding to 3, the operation efficiency of the fuel cell 54 and the engine 10 is reversed at the load of the value c as a boundary. In each operation state, by referring to the map as described above, it is possible to realize the proper use of the fuel cell 54 and the engine 10 based on the operation efficiency.

Returning to FIG. 3, the drive control processing will be described continuously. In steps S10 and S12, when it is determined that the FC fuel remaining amount is insufficient and the gasoline remaining amount is sufficient, the use of the fuel cell 54 is avoided. CPU
Is based on the operating efficiency, the battery 50 and the engine 10
And use them properly. The CPU calculates the operating efficiency ηb when the motor 20 is driven by the battery 50 and the operating efficiency ηe when driven by the engine 10 (step S26), and selects the side with the higher operating efficiency as the power source. That is, when “ηe> ηb”, the vehicle runs using the engine 10 as a power source (steps S28 and S20). In other cases, the vehicle runs using the motor 20 powered by the battery 50 as a power source (step S28, S30).

The method for calculating the operating efficiency of the engine 10 is the same as that in step S14. Operating efficiency η of battery 50
b is given by the following equation. ηb = ηech × ηgen × ηout × ηmot × η
m; The contents of each element efficiency are as follows.

Ηech (0 <ηech <1.0 real number)
Is the operating efficiency of the engine 10 when charging the battery 50. The battery 50 is mainly used for the auxiliary drive motor 8.
The charging efficiency was calculated on the assumption that the battery was charged by power generation using 0. This value is not the operating efficiency of the engine 10 in the operating state where the calculation in step S26 is performed, but the operating efficiency in a state where the battery 50 is charged at a relatively high rate.

Ηgen (0 <ηgen <1.0 real number)
Is the power generation efficiency of the accessory driving motor 80. This corresponds to the ratio between the generated power and the power output from the engine 10 for charging.

Η out (0 <η out <1.0 real number)
Is the discharge efficiency of the battery 50. It corresponds to the ratio of the power actually output from the battery 50 in each operation state to the power that can be theoretically output. ηmot and ηm
Is as described above.

When it is determined in steps S10 and S12 that both the FC fuel remaining amount and the gasoline remaining amount are insufficient, the operation of the power source is stopped because both the fuel cell 54 and the engine 10 cannot be used. (Step S2
4). When the power of the battery 50 is sufficiently remaining, the operation of the motor 20 using the battery 50 as a power source may be performed as an emergency operation mode as long as the power is not excessively consumed.

Although not explicitly shown in the flow chart of FIG. 3, in order to avoid frequent switching of the power source, it is determined whether the power source should be used properly (steps S10, S12, S2).
2, S16 and S28) preferably have a certain hysteresis. For the same purpose, the execution cycle of the drive control process may be made relatively long. As an example, it may be executed every time the traveling distance or the traveling time reaches a predetermined value. Furthermore, the drive control process may be executed only when the operation unit of the vehicle is in a predetermined state where the influence on the power source switching is low. For example, it may be executed only when the shift lever of the transmission 100 is in a predetermined state such as a neutral position.

According to the hybrid vehicle of the present embodiment described above, the fuel cell 54 and the engine 10 can be selectively used based on the driving efficiency in each driving state. Therefore, efficient operation can be realized.
As is clear from the processing shown in FIG. 3, the efficiency of the fuel cell 54 and the efficiency of the engine 10 are compared only when both the FC fuel and the gasoline are sufficiently remaining, so that an increase in the load due to the calculation of the operation efficiency can be avoided. By appropriately setting a reference value for determining whether or not sufficient FC fuel and gasoline remain, waste of each fuel in the drive control process can be avoided.

In this embodiment, when the FC fuel is insufficient, the battery 50 and the engine 10 are selectively used by comparing the operating efficiencies of the two. Therefore, even in a situation where the fuel cell 54 cannot be used, it is possible to realize efficient operation as much as possible.

In this embodiment, when the FC fuel is sufficiently left, that is, when both the fuel cell 54 and the battery 50 are available, the fuel cell 54 is used preferentially. Since the fuel cell 54 often has higher energy efficiency than the battery 50, efficient operation can be realized by performing such proper use.

D. Second Embodiment In the first embodiment, the control in which the driving source is selectively used in consideration of the operation efficiency, that is, the energy efficiency, has been described. The second embodiment exemplifies control in which a plurality of types of efficiencies including energy efficiency are comprehensively determined and drive sources are selectively used. As an example, the second embodiment exemplifies a control that considers three types of economic efficiency, energy efficiency, and emission suppression efficiency.

FIG. 5 is a schematic configuration diagram of the second embodiment. The second embodiment differs from the first embodiment in that the number of input elements to the efficiency calculation unit 71 of the control unit 70 increases. Other configurations are the same as those of the first embodiment.

In the second embodiment, the driver can set whether or not to consider the economic efficiency at the time of drive control by using the touch panel 90. A panel display section 79 provided in the control unit 70 controls input and output of data using the touch panel 90. By the operation of the panel display section 79, an interface for setting on / off of economic efficiency and setting a fuel unit price is displayed on the touch panel 90 as shown in the figure. The state shown in the figure is set so that the setting of the economic efficiency is ON, that is, in the control described later, the economic efficiency is considered. The driver can switch the economic efficiency setting off by operating the touch panel 90. It is not always necessary to use a touch panel as the switch for setting the economic efficiency, but a push button or other switch that can take two states, ON and OFF, may be used.

The fuel unit price setting is a value used when calculating economic efficiency. In the hybrid vehicle of this embodiment, gasoline and fuel
Since methanol is used as a fuel, the respective unit prices can be input. These unit prices may be input by the driver or may be obtained from an external information center IC via the network NET by providing the panel display unit 79 with a wireless communication function.

FIG. 5 is a flowchart of a drive control process according to the second embodiment. Here, the processing on the assumption that both the fuel cell 54 and the engine 10 are in an operable state has been exemplified. Prior to the processing shown in FIG.
As in the embodiment, based on the remaining amount of FC fuel and gasoline,
It may be determined whether or not both are operable. Although FIG. 5 illustrates the use of the fuel cell 54 and the engine 10 properly, if the fuel cell 54 is not usable, the use of the battery and the engine 10 may be performed separately.

When the drive control is started, the control unit 7
The CPU of 0 determines whether or not a mode that prioritizes economic efficiency is set (step S110). this is,
The determination is made based on the settings on the touch panel 90 shown in FIG. When the economic efficiency setting is ON, the economic efficiency of the fuel cell 54 and the economic efficiency of the engine 10 are compared, and both are used properly. That is, the CPU operates the fuel cell 54
The economic efficiency εf of the engine 10 and the economic efficiency εe of the engine 10 are calculated (step S112), and the one with the higher economic efficiency is selected as the drive source (steps S114, S116, S11).
8).

A method for calculating the economic efficiency will be described. According to the equation described in the first embodiment, the energy efficiency η of the engine 10
e and the energy efficiency ηf of the fuel cell 64 are calculated. Energy efficiency represents the ratio of the theoretical value to the actual value for the energy obtained from a unit volume of fuel. Since the theoretical value of energy obtained from a unit volume of fuel is known, the fuel consumption rate can be obtained by using this theoretical value and energy efficiency. Of course, the relationship between the operating state and the fuel consumption rate may be stored in a map or the like in advance. The cost for obtaining unit energy is calculated by multiplying the fuel consumption rate obtained by these methods by the unit price of each fuel. Economic efficiency is obtained by taking the reciprocal of this cost. Therefore, higher economic efficiency means that energy can be obtained at lower cost.

On the other hand, if it is determined in step S110 that the economic efficiency setting is off, the CPU executes the proper use of the drive source in consideration of the emission suppression efficiency and the energy efficiency. When the CPU determines that the driving state of the vehicle is in a state where the emission suppression efficiency should be prioritized (step S120), the CPU selects the fuel cell as a drive source (step S126). A method for determining whether to give priority to the emission suppression efficiency will be described later. If it is determined in step S120 that the emission suppression efficiency does not need to be prioritized, the CPU determines the energy efficiency η of the fuel cell 64.
f, calculating the energy efficiency ηe of the engine (step S
122), the one with higher energy efficiency is selected as the drive source (steps S124, S126, S118). The method of calculating the energy efficiency is the same as in the first embodiment.

The determination method in step S120 will be described. Emission suppression efficiency means the reciprocal of the amount of emission with respect to the output of unit energy. The more the energy can be output with low emission, the higher the emission suppression efficiency. Since the fuel cell 64 has extremely low emission, in this embodiment, the emission suppression efficiency is determined based on whether the emission of the engine 10 is within an allowable range. That is, when the emission of the engine 10 is within the allowable range, it is not necessary to give priority to the emission suppression efficiency. When the emission is out of the allowable range, the emission suppression efficiency is given priority. In the present embodiment, when any one of the first condition based on the speed and torque of the vehicle, the second condition based on the area where the vehicle is traveling, and the third condition based on the time zone is satisfied, the emission control is performed. It is determined that efficiency should be given priority.

The first condition will be described. Engine 1
It is known that a value of 0 indicates that the emission amount is large when the vehicle speed and the torque are relatively low, for example. A region in which the emission exceeding the target amount is emitted is set in advance in relation to the vehicle speed and the torque, and if the traveling state of the vehicle belongs to this driving region, it is determined that the first condition is satisfied. Is determined.

Next, the second condition will be described. The allowable amount of emission varies depending on the traveling area of the vehicle. For example, in a metropolitan area, a residential area, a hospital, and the like, the allowable amount of emission is low. The areas where emissions are to be suppressed are set in advance, and the second
Is determined to be satisfied. The traveling area of the vehicle can be obtained from the navigation system.

The third condition will be described. The allowable amount of emission also varies depending on the time zone in which the vehicle travels. For example, the emission allowance is low early in the morning or late at night. These time zones are time zones in which not only emission but also noise should be suppressed. Here, both are taken into account, and are represented by the emission allowance. If the current time belongs to a preset time zone such as early morning or midnight, it is determined that the third condition is satisfied.

According to the control of the second embodiment described above, by taking into account the economic efficiency, the emission suppression efficiency, and the energy efficiency in a predetermined priority order, it is possible to realize the driving according to various situations relating to the running of the vehicle. can do.
For example, the economic burden on the driver can be reduced by considering the economic efficiency. By considering the emission suppression efficiency, it is possible to realize an environment-friendly operation according to the situation.

E. Modification: In the embodiment, the fuel cell 54, the engine 10, and the battery 50 are represented by a map or a function.
The case where the operating efficiency of the vehicle is sequentially obtained is illustrated. In contrast,
A map that specifies a driving source in advance according to the driving state may be used. A map in which a flag indicating a driving source is associated with a parameter representing an operating state such as a load, a temperature of the fuel cell 54, and an engine water temperature can be used. By using such a map, the calculation load at the time of specifying the drive source can be reduced.

In the embodiment, a vehicle in which the battery 50 can be used as a power source has been exemplified. The present invention is also applicable to vehicles without the battery 50. In this case, FIG.
In step S26, steps S26, S28, and S30 are omitted, and a control process configured to switch between driving the engine (step S20) and stopping the operation (step S24) according to the presence or absence of gasoline (step S22) is applied. be able to.

The operation efficiency ηe of the engine 10 may be specified by considering any one of the prime mover efficiency ηeng and the gasoline efficiency ηg, in addition to considering all the element efficiencies exemplified in the embodiment. The operating efficiency ηe can be specified in various other modes.

The operating efficiency ηf of the fuel cell 54 is related to the system temperature of the fuel cell, the amount of power generation, the elapsed time from the start, and the degree of deterioration of the fuel cell, in addition to the case where all the element efficiencies exemplified in the embodiment are considered. It can be specified in various ways, at least taking into account any of the predetermined parameter values.
These parameters may be applied to each of the element efficiencies exemplified above, or the operating efficiency η may be divided without being divided into the element efficiencies.
You may apply so that f may be specified. The system temperature is
When a reformer or the like is provided, the temperature can be considered in addition to the temperature of the fuel cell 54 alone.

In the embodiment, the fuel cell 5 is determined based on the presence or absence of the FC fuel.
4 was used (step S10 in FIG. 3). Usability may be determined by taking into account the power generation rating of the fuel cell 54 to determine whether or not the fuel cell 54 can be used. In addition, the temperature of the fuel cell 54 may be considered. In addition, the availability of the fuel cell 54 may be determined in consideration of the output rating of the motor 20 using the fuel cell 54 as a power source. If the output rating of the motor 20 is less than the required torque and the number of revolutions, it can be determined that the fuel cell 54 cannot be used in the sense that the driving method using the fuel cell 54 as a power source cannot be applied.

The second embodiment is not limited to the three efficiencies described above, but may include efficiencies from various viewpoints. In addition, the priority order considering a plurality of efficiencies is not limited to the illustrated order. For example, the priority may be settable by the driver.

In the above embodiment, the case where the fuel cell and the engine are used as drive sources has been described as an example. However, the present invention is applicable to various moving bodies using two or more drive sources having different characteristics relating to operating conditions and efficiency. It is possible. In the embodiment, the hybrid vehicle in which the engine 10 and the motor 20 are connected in series has been exemplified. However, the invention is not limited to this, and various configurations in which both are the power sources can be adopted.

Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that various configurations can be adopted without departing from the spirit of the present invention. For example, the above-described control processing may be realized by software or by hardware.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hybrid vehicle as an embodiment.

FIG. 2 is an explanatory diagram illustrating a relationship between a traveling state of a vehicle and a power source.

FIG. 3 is a flowchart of a drive control processing routine.

FIG. 4 is an explanatory diagram exemplifying a map that gives driving efficiency.

FIG. 5 is a schematic configuration diagram near a control unit 70 in a second embodiment.

FIG. 6 is a flowchart of a drive control processing routine according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Crankshaft 15 ... Output shaft 16 ... Differential gear 17 ... Axle 18 ... Input clutch 19 ... Auxiliary clutch 20 ... Motor 30 ... Torque converter 50 ... Batteries 51, 55 ... Changeover switches 52, 56 ... Drive circuit 54 ... Fuel cell 70 ... Control unit 71 ... Efficiency calculation unit 72 ... Drive control unit 73 ... Operation state sensor 74 ... Operation unit 75, 76 ... Remaining amount sensor 78 ... Vehicle speed sensor 79 ... Panel display unit 80 ... Auxiliary device driving motor 82 ... Auxiliary equipment driving device 90 ... Touch panel 100 ... Transmission device 102 ... Pump 104 ... Hydraulic control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01M 8/00 H01M 8/00 Z A ZHV ZHV // B60K 6/02 B60K 9/00 EF term (reference ) 3G084 AA00 AA08 DA02 DA10 EA11 EB05 EB06 EB09 FA00 FA05 FA06 FA10 FA20 3G093 AA00 AA05 AA07 AA16 AA19 BA19 BA20 DA05 DA06 DB00 DB05 DB11 DB15 EC01 EC02 FA00 FA10 FA11 FB06 5H115 PA16 PA13 PI03 Q03

Claims (13)

[Claims] A first driving source having a first relationship between an operating state and an efficiency of the moving body, and a second driving source having a first relation between the operating state and the efficiency of the moving body. A second driving source having the following relationship; operating state detecting means for detecting an operating state of the moving body; and a first driving source and a second driving source corresponding to the second operating source according to the detected operating state.
And a control means for performing driving using any one of the driving sources based on the efficiency comparison of the driving sources. 2. The moving body according to claim 1, wherein the control unit obtains a first efficiency based on the operating state when the first driving source is used for driving. An efficiency specifying means, a second efficiency specifying means for obtaining an efficiency when driving is performed using the second drive source, based on the operation state, and a first and a second drive source, And a drive control means for performing drive using an output on the side with higher efficiency. 3. The moving body according to claim 2, further comprising: a first storage unit that stores the first relationship; and a second storage unit that stores the second relationship. A moving body wherein the first efficiency specifying means and the second efficiency specifying means obtain the efficiency by referring to the first storage means and the second storage means, respectively. 4. The moving body according to claim 1, wherein at least one of the first relation and the second relation is:
A moving body that performs the efficiency comparison in consideration of an operation state of the drive source, wherein the relation varies in accordance with an operation state of each drive source. 5. The moving body according to claim 4, wherein the operating state is represented by at least one of a moving speed, a required torque, remaining fuel of a driving source, and an operating temperature of the driving source as parameters. body. 6. The moving body according to claim 1, wherein the first drive source is a heat engine, and the second drive source is an electric motor powered by a fuel cell. 7. The moving body according to claim 1, wherein the efficiency is represented using at least one of energy efficiency, economic efficiency, and emission control efficiency. 8. The moving body according to claim 1, wherein the control unit performs the driving by comparing a plurality of types of the efficiencies of the first and second driving sources. 9. The moving body according to claim 8, wherein the control unit considers the plurality of types of efficiency according to a predetermined priority. 10. The moving body according to claim 9, further comprising: a setting unit configured to allow a driver to set whether or not to consider at least part of the plurality of types of efficiency in the control or to set the priority. Moving body. 11. The moving body according to claim 1, wherein a first availability determining unit that determines availability of the first driving source, and a second unit that determines availability of the second driving source. And a control unit that executes the control only when it is determined that both the first and second drive sources are in a usable state. . 12. The moving body according to claim 11, wherein the first drive source is a heat engine, the second drive source is an electric motor powered by a fuel cell, A power storage device serving as an alternative power supply for the fuel cell; anda power storage efficiency specifying means for obtaining an operation efficiency when driving by using an output of the power storage device based on the operation state, wherein the control means uses the fuel cell. A moving body which is means for performing driving by using an output of the heat engine and the storage device on the side of higher operation efficiency when in the disabled state. 13. A first driving source having a first relationship between an operating state and efficiency of the moving body, and a second relationship between an operating state and efficiency of the moving body. And (b) detecting the operating state of the moving body; and (b) detecting the operating state of the moving body based on the detected operating state. (C) calculating the operating efficiency when driving using the output of the second driving source based on the detected operating state; A control method, comprising: (d) selecting, as the drive source, a side with higher operation efficiency from among the first and second drive sources.