JP4134502B2 - Control device for hybrid vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving force source control technique in a hybrid vehicle including a heat engine and an electric motor as driving force sources.
[0002]
[Prior art]
A hybrid vehicle including an internal combustion engine (heat engine) and an electric motor as a driving force source has been put into practical use. Generally, the electric motor has a high efficiency in a region where the vehicle required torque is small, and the internal combustion engine has a characteristic that the efficiency is high in a region where the vehicle required torque is large. Therefore, the hybrid vehicle normally selects the internal combustion engine, the electric motor, or the internal combustion engine and the electric motor as a driving force source according to the vehicle required torque required for the vehicle, and causes the selected driving force source to output the vehicle required torque. Running.
[0003]
[Problems to be solved by the invention]
However, in the conventional hybrid vehicle, when the required torque increases in the operation region of the internal combustion engine, the required torque is output by operating the internal combustion engine and the electric motor. Further, a conventional hybrid vehicle uses a secondary battery as a power source for an electric motor, and operation control of a driving force source is performed on the premise that the secondary battery is charged using an internal combustion engine.
[0004]
Therefore, when using a self-power generation type power source such as a fuel cell, there has been a problem that conventional driving power source operation control may not be optimal. In addition, the internal combustion engine and the electric motor as the driving force source cannot be operated under conditions with high energy efficiency, and there is a possibility that a high energy efficiency cannot be realized as a whole vehicle.
[0005]
The present invention has been made to solve the above-described problem, and in a vehicle including a motor and a heat engine that receive power from a self-sustained power source as a driving power source, each of the motor and the heat engine has high energy. The purpose is to drive with efficiency. It is another object of the present invention to provide a control device for a hybrid vehicle that can be operated under conditions of high energy efficiency as a whole vehicle.
[0006]
[Means for solving the problems and their functions and effects]
In order to solve the above problems, a first aspect of the present invention includes a heat engine that generates a driving force by combustion of fuel and an electric motor that generates a driving force by consuming electric power from a spontaneous power source as a driving force source. In addition, when a heat engine is used as a driving force source, a control device for a hybrid vehicle is provided that causes the heat engine to operate in an operation region where fuel efficiency is optimal. A control apparatus for a hybrid vehicle according to a first aspect of the present invention includes: a required output calculation unit that calculates a required output required for the vehicle; and a driving force source that can generate the required output more efficiently. Drive power source control means for selecting one of the heat engine and the electric motor or a combination of both and outputting the required output is provided.
[0007]
According to the hybrid vehicle control device of the first aspect of the present invention, the requested output is output by the energy-efficient driving force source, so that the vehicle as a whole is driven under conditions of high energy efficiency. be able to.
[0008]
In the hybrid vehicle control device according to the first aspect of the present invention, when the driving force source control means selects the heat engine as the driving force source, the heat engine is in an operating region where the fuel efficiency is optimal. The required output may be output by operating at. In such a case, the energy efficiency of the vehicle can be improved while suppressing fuel consumption of the heat engine. Further, when the electric motor is selected as the driving force source, the driving force source control means may output the required output by the electric motor. In such a case, the required output can be output by a motor with high energy efficiency.
[0009]
In the hybrid vehicle control device according to the first aspect of the present invention, when the driving force source control means selects a combination of the heat engine and the electric motor as a driving force source, the fuel efficiency of the heat engine is reduced. The required output may be output by the heat engine and the electric motor by operating in an optimal operating region. In such a case, the heat engine and the electric motor can be operated with energy efficiency.
[0010]
The hybrid vehicle control device according to the first aspect of the present invention may further include power transmission means that enables the heat engine to operate in an arbitrary operation region depending on the vehicle speed of the vehicle. In such a case, since the heat engine can be operated in an arbitrary operation region, the heat engine can be operated in an operation region where the fuel efficiency is optimal.
[0011]
According to a second aspect of the present invention, a heat engine that generates driving force by combustion of fuel and an electric motor that generates driving force by consuming electric power from a spontaneous power source are provided as a driving force source, and heat is generated as a driving force source. When an engine is used, a control device for a hybrid vehicle that operates a heat engine in an operation region where fuel efficiency is optimal is provided. A control device for a hybrid vehicle according to a second aspect of the present invention provides:
Requested torque calculating means for calculating required torque required for the vehicle;
Torque difference calculating means for obtaining a torque difference between the current torque of the heat engine and the required torque in an operation region where the fuel efficiency is optimal;
Driving force source selection means for selecting a driving force source capable of generating the calculated torque difference with the highest energy efficiency from one or a combination of the heat engine and the electric motor;
When the heat engine is selected as a drive force source by the drive force source selection means, the drive force source that outputs the torque difference by operating the heat engine in an operation region where the fuel efficiency is optimal. And a control means.
[0012]
According to the hybrid vehicle control device of the second aspect of the present invention, when the requested torque is output by the driving power source with high energy efficiency and is selected as the driving power source, the heat engine is made fuel efficient. Therefore, the vehicle can be driven under conditions of high energy efficiency as a whole vehicle.
[0013]
In the hybrid vehicle control device according to the second aspect of the present invention, the driving force source control means calculates the torque difference when the electric motor is selected as the driving force source by the driving force source selection means. You may make it output with the said electric motor. By providing such a configuration, when the energy efficiency of the electric motor is high, a torque difference can be output by the electric motor, and the energy efficiency of the entire vehicle can be improved.
[0014]
In the hybrid vehicle control device according to the second aspect of the present invention, the driving force source control means is configured such that the driving force source selection means selects a combination of the heat engine and the electric motor as a driving force source. Causes the heat engine to operate in an operation region where the fuel efficiency is optimal to generate a fuel efficiency priority torque smaller than the required torque, and an insufficient torque difference between the required torque and the fuel efficiency priority torque is generated by the electric motor. The torque difference may be output by outputting. With such a configuration, the heat engine can be operated in an operating region where the fuel efficiency is optimal and the fuel efficiency priority torque can be output, and the difference in insufficient torque can be compensated for by the electric motor to improve the energy efficiency of the entire vehicle. The required torque can be output while.
[0015]
In the hybrid vehicle control apparatus according to the second aspect of the present invention, the fuel efficiency priority torque is a torque that is closest to the required torque and that can be output by the heat engine in an operating region where the fuel efficiency is optimal. Also good. When such a configuration is provided, most of the required torque can be output by the heat engine.
[0016]
The hybrid vehicle control device according to the second aspect of the present invention further includes:
A transmission that decelerates the engine rotational speed of the heat engine by changing a transmission ratio;
There may be provided transmission control means for controlling a transmission ratio of the transmission so that the engine rotational speed of the heat engine at the time of outputting the required torque or the fuel efficiency priority torque matches the current vehicle speed of the vehicle. With such a configuration, it is possible to maintain the vehicle speed at the current vehicle speed regardless of fluctuations in the engine rotational speed that occur as a result of operating the heat engine in an operation region where fuel efficiency is optimal.
[0017]
In the hybrid vehicle control device according to the second aspect of the present invention, the spontaneous power source may be a fuel cell that generates power by consuming fuel cell fuel.
[0018]
In the hybrid vehicle control device according to the second aspect of the present invention,
The energy efficiency is
The heat engine includes a fuel efficiency related to the amount of heat that can be generated by the fuel, a heat engine efficiency that is an efficiency in converting the generated heat amount into torque, and a drive efficiency associated with the operation of the heat engine,
The electric motor may include fuel efficiency related to the amount of electric power that can be generated from the fuel for the fuel cell, electric motor efficiency that is efficiency when the electric power is converted into torque, and drive efficiency that accompanies the operation of the electric motor.
[0019]
According to a third aspect of the present invention, there is provided a control for a hybrid vehicle including, as a driving force source, a heat engine that consumes combustion fuel to generate driving force and an electric motor that consumes electric power from the fuel cell to generate driving force. Provide a method. In the hybrid vehicle control method according to the third aspect of the present invention,
Calculate the required torque required for the vehicle,
During the operation of the heat engine, the heat engine is operated on an optimal fuel consumption curve that optimizes fuel consumption of the heat engine expressed as a characteristic line of engine speed and output torque of the heat engine. ,
Obtaining a torque difference between the current torque of the heat engine at the first operating point on the optimum fuel consumption curve and the required torque;
A driving force source capable of generating the calculated torque difference with the highest energy efficiency is selected from one or a combination of the heat engine and the electric motor;
When the heat engine is selected as a driving force source, the torque difference is output by operating the heat engine at a second operation point on the optimum fuel consumption curve corresponding to the required torque. And
[0020]
According to the hybrid vehicle control method of the third aspect of the present invention, it is possible to obtain the same functions and effects as those of the hybrid vehicle control apparatus according to the first and second aspects of the present invention.
[0021]
In the hybrid vehicle control method according to the third aspect of the present invention, when the electric motor is selected as a driving force source, the torque difference may be output by the electric motor.
[0022]
In the hybrid vehicle control method according to the third aspect of the present invention, when the combination of the heat engine and the electric motor is selected as a driving force source, the optimum fuel efficiency corresponding to the fuel efficiency priority torque smaller than the required torque. The fuel efficiency priority torque is output by operating the heat engine at a third operating point on the curve, and the torque is output by causing the motor to output an insufficient torque difference between the required torque and the fuel efficiency priority torque. The difference may be output.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a control apparatus for a hybrid vehicle according to the present invention will be described based on an embodiment with reference to the drawings.
[0024]
A schematic configuration of a vehicle in which the hybrid vehicle control device according to this embodiment can be used will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of a vehicle to which the hybrid vehicle control device according to this embodiment can be applied.
[0025]
The vehicle includes an engine (combustion engine) 10 and a drive motor (electric motor) 20 as a power source, a planetary gear device 30 that mechanically synthesizes and distributes the outputs of the engine 10 and the drive motor 20, and a maximum reduction ratio and a minimum. A continuously variable transmission (CVT) 40 capable of steplessly changing the speed reduction ratio between the speed reduction ratios is provided. The engine 10 is connected to the power input shaft of the planetary gear device 30 via the crankshaft (output shaft) 11, the damper 18 and the first clutch C 1, and the drive motor 20 is connected to the planetary gear device 30 via the rotor 21. Connected to the power input shaft. The driving force output shaft of the planetary gear device 30 is connected to the power input shaft of the CVT 40, and the power output shaft of the CVT 40 is connected to the drive shaft 50. The drive shaft 50 is connected to a wheel 53 via a differential gear (including a final gear) 51 and an axle 52.
[0026]
The engine 10 is, for example, a general gasoline engine that uses gasoline as fuel, and its operation state is controlled by the control unit 60. The engine 10 includes a crankshaft 11 that outputs the generated output to the outside, an injector that injects a predetermined amount of fuel based on a command from the control unit 60, and an igniter that generates an electric spark via a spark plug at a predetermined timing. (Both not shown) etc. are provided. The engine 10 according to the present embodiment includes an electronically controlled throttle valve 13 that is mechanically linkless with the accelerator pedal 12, and controls the throttle opening independently of the amount of depression of the accelerator pedal 12. Can do. An engine speed sensor 70 (see FIG. 3) for detecting the speed of the engine 10 is disposed on the crankshaft 11. Auxiliary equipment 14 such as a power steering hydraulic pump and an air conditioner (A / C) compressor for circulating a refrigerant for an air conditioner is disposed around the engine 10. The auxiliary machine 14 is connected to the crankshaft 11 via a timing belt 15 and an electromagnetic clutch 16, and the driving force output from the crankshaft 11 is transmitted via the timing belt 15 during operation of the engine 10. Driven by.
[0027]
An auxiliary machine driving motor 17 is further disposed around the engine 10. The accessory drive motor 17 is coupled to the accessory 14 via the timing belt 15. The accessory driving motor 17 drives the accessory 14 via the timing belt 15 while the engine 10 is stopped based on a command from the control unit 60. In such a case, the electromagnetic clutch 16 is turned off (released) according to a command from the control unit 60, and the coupling between the accessory drive motor 17 and the engine 10 is cut off to reduce the load on the accessory drive motor 17. The The accessory driving motor 17 is driven by the engine 10 to function as a generator, and also functions as a starter motor when starting the engine 10.
[0028]
The drive motor 20 functions as a motor that converts electrical energy into mechanical energy when a driving force from the motor is required, and functions as a generator that converts mechanical energy into electrical energy during regeneration, charging, and the like. It is a three-phase synchronous motor. The drive motor 20 includes a rotor 21 having a plurality of permanent magnets on the outer peripheral surface, and a stator 22 around which a three-phase coil for forming a rotating magnetic field is wound. The drive motor 20 rotates by the interaction between the magnetic field generated by the permanent magnets provided in the rotor 22 and the magnetic field formed by the three-phase coil of the stator 22. When the rotor 22 is driven by an external force, an electromotive force is generated at both ends of the three-phase coil by the interaction of these magnetic fields. A resolver 71 (see FIG. 3) for detecting the rotational speed of the drive motor 20 is disposed on the rotary shaft 23.
[0029]
As a power source for the drive motor 20 and the accessory drive motor 17, a fuel cell 200 and a battery (secondary battery) 210 are provided. In this embodiment, the fuel cell 200 is basically used as the main power source for the motors 17 and 20. The battery 210 functions as an auxiliary power source when the fuel cell 200 cannot supply sufficient power, such as a period until the operation state of the fuel cell 200 is stabilized, and also serves as a main power source for the control unit 60 and other electrical components. Function as.
[0030]
Inverters 220 and 230 and a changeover switch 240 are arranged between the motors 17 and 20 and the power supplies 200 and 210. The inverters 220 and 230 are connected to the control unit 60 through signal lines, and supply control currents to the motors 17 and 20 based on commands from the control unit 60. The changeover switch 240 is a switch for arbitrarily changing the connection state between the motors 17 and 20 and the power supplies 200 and 210, and the changeover switch 240 is connected to the stator 21 of the motors 17 and 20.
[0031]
The switching operation of the changeover switch 240 will be described with reference to FIG. FIG. 2 is an explanatory diagram schematically showing the switching operation of the changeover switch 240. The changeover switch 240 is in a state in which the fuel cell 200 or the battery 210 is selectively connected to the accessory driving motor 17 and a state in which any power source 200, 210 is not connected to the accessory driving motor 17. obtain. The changeover switch 240 can be in a state in which the fuel cell 200 or the battery 210 is selectively connected to the drive motor 20 and a state in which no power source 200, 210 is connected to the drive motor 20. Accordingly, power can be supplied from any of the power supplies 200 and 210 to the motors 17 and 20 simultaneously, and power can be supplied from any of the power supplies 200 and 210 only to either of the motors 17 and 20. Can do. It is also possible to store power in the power source 210 by connecting the power source 210 to the accessory driving motor 17 and operating the accessory driving motor 17 as a generator.
[0032]
The planetary gear device 30 implements an electric torque converter together with the drive motor 20. That is, in this embodiment, the function of the torque converter is realized by electrically and mechanically controlling the operations of the drive motor 20 and the planetary gear device 30 in place of a general fluid torque converter. The planetary gear device 30 includes a double planetary type first planetary gear device 31 and a simple planetary type second planetary gear device 32 which are arranged close to each other in parallel. The first and second planetary gear devices 31 and 32 have a common ring gear R and carrier C, and a common pinion gear in which the outer pinion gear of the first planetary gear device 31 and the pinion gear of the second planetary gear device 32 are integrated. It is a Ravigne type planetary gear device having P1.
[0033]
The first sun gear S1 of the first planetary gear device 31 is directly connected to the rotor 21 of the drive motor 20, and the second sun gear S2 of the second planetary gear device 32 is connected to the crankshaft via the first clutch C1 and the damper 18. 11 and the other end. The first sun gear S1 and the second sun gear S2 can be connected via the second clutch C2, and the first sun gear S1 is connected to the crankshaft 11 of the engine 10 by engaging the second clutch C2. The The ring gear R is connected to the shaft of the input side pulley 41 of the CVT 40 and meshes with the second sun gear S2 via a common pinion gear P1 that can rotate. The carrier C is fixed to the housing via the brake B, and meshes with the ring gear R via a rotatable common pinion gear P1 and meshes with the first sun gear S1 via an independently rotatable pinion gear P2.
[0034]
The first clutch C1, the second clutch C2, and the brake B are multi-plate hydraulic clutches that are joined when a plurality of clutch plates stacked on each other are pressed by a hydraulic actuator and released by releasing the press. is there.
[0035]
The CVT 40 includes an input side pulley 41, an output side pulley 42, and a steel belt 43 mounted on both pulleys 41, 42. The input-side pulley 41 and the output-side pulley 42 are each provided with a hydraulic actuator (not shown), and the outer peripheral diameter on which the steel belt 43 is hung is changed by the hydraulic actuator according to the driving state of the vehicle. Thus, the pulley ratio is changed by changing the groove width of each pulley 41, 42, and a desired reduction ratio is realized. The shaft of the input side pulley 41 is connected to the ring gear R as described above, and is connected to the first sun gear S1 via the common pinion gear P1 and the independent pinion gear P2, and to the second sun gear S2 via the common pinion gear P1. The shaft of the output pulley 42 is connected to the drive shaft 50, and the driving force output from the output pulley 42 is transmitted to the wheel 53 via the drive shaft 50, the differential gear 51, and the axle 52.
[0036]
Next, a control circuit configuration of the hybrid vehicle control device according to this embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing a control circuit configuration of the hybrid vehicle control apparatus according to the present embodiment. The control unit 60 includes a hybrid ECU (electronic control unit) 600, an engine ECU 610, and a transmission ECU 620. Each ECU 600, 610, and 620 includes a CPU, ROM, RAM, and the like (not shown). These ECUs are merely examples, and for example, a brake ECU or the like may be provided separately from the hybrid ECU 600.
[0037]
Hybrid ECU 600 is an ECU that forms the core of control unit 60, and is connected to engine ECU 610 and transmission ECU 620 via a signal line so as to be capable of bidirectional communication. The hybrid ECU 600 includes an engine speed sensor 70 that detects the speed of the crankshaft 11 of the engine 10, a resolver 71 that detects the speed of the drive motor 20, a vehicle speed sensor 72 that detects the vehicle speed, and a shift position. A shift position sensor 73, an accelerator opening sensor 74 for detecting an accelerator depression amount as an accelerator opening, and a throttle opening sensor 75 for detecting a throttle opening are connected via a signal line. The hybrid ECU 600 further includes a methanol remaining amount sensor 76 that detects the remaining amount of methanol that is the fuel of the fuel cell 200 and an SOC sensor 77 that detects the charging rate of the battery 210 via signal lines. The remaining amount sensor 76 is disposed in the methanol tank 110, and the fuel cell 200 is connected to the methanol tank 110 via a reformer (not shown) methanol pipe.
[0038]
In addition to the hybrid ECU 600, as shown in FIG. 4, various sensors are connected to the input port side via signal lines, and various control circuits are connected to the output port side via signal lines.
[0039]
The hybrid ECU 600 stores a map for determining operation switching between the engine 10 and the drive motor 20 in the ROM, an energy efficiency map of the engine 10 and the drive motor 20, a map for obtaining the throttle opening from the accelerator opening, and the like. is doing.
[0040]
The engine ECU 610 controls the injector based on the request from the hybrid ECU 600 to realize the required fuel injection amount, and controls the operating state of the engine 10 by controlling the ignition timing, the throttle valve opening, and the like. Further, when the vehicle travels only by the drive motor 20 (hereinafter referred to as “EV travel”), the fuel injection to the engine 10 is stopped and the operation of the engine 10 is stopped according to a request from the hybrid ECU 600.
[0041]
The transmission ECU 620 controls the engagement state of the clutches C1 and C2 and the brake B via hydraulic actuators according to the request from the hybrid ECU 600, and also controls the groove widths of the input side pulley 41 and the output side pulley 42. The pulley ratio is changed, and the rotational speed (rotation speed) of the engine 10 is appropriately decelerated and transmitted to the wheels.
[0042]
The hybrid ECU 600 controls the auxiliary machine driving motor 17 via the inverters 220 and 230 and the changeover switch 240 while the engine is stopped, and realizes driving of the auxiliary machine 14 when the engine 10 is stopped. When the hybrid ECU 600 restarts the operation of the engine 10 from the engine stopped state, the hybrid ECU 600 drives the accessory drive motor 17 to increase the engine speed to the start speed, and controls the fuel injection control and ignition for the engine ECU 610. Request control.
[0043]
Next, a basic traveling operation of the hybrid vehicle executed by the hybrid vehicle control apparatus having the above configuration will be described with reference to FIGS. FIG. 5 is an explanatory diagram showing a map used to determine which of the engine 10 and the driving motor 20 is used as a driving force source when the vehicle moves forward based on the vehicle speed, output torque (accelerator opening), and shift position. is there. FIG. 6 is an explanatory diagram showing a map used to determine which of the engine 10 and the driving motor 20 is used as a driving force source when the vehicle is driven backward based on the vehicle speed, the output torque (accelerator opening), and the shift position. is there. FIG. 7 is an explanatory diagram showing the relationship between the clutch C1, C2 and the brake B engaged state, and the planetary gear unit 30 shift state, and is classified according to the driving force source, shift position (see FIG. 8), and the like. ing. FIG. 8 is an explanatory diagram showing an example of the shift lever position arrangement.
[0044]
Note that the maps shown in FIGS. 5 and 6 are merely examples of maps used to determine the driving force source that outputs the vehicle required torque. Further, when acceleration is required in the traveling area of the engine 10, the necessary output can be assisted by the engine 10 or the drive motor 20. This detailed control will be described later.
[0045]
When the ignition position is at the vehicle start position (STA), hybrid ECU 600 acquires vehicle speed v and accelerator opening θ from vehicle speed sensor 72 and accelerator opening sensor 74, respectively. The hybrid ECU 600 determines which of the engine 10 and the driving motor 20 is used as a driving force source from the map of FIG. 5 or 6 based on the acquired vehicle speed v and accelerator opening θ. When the vehicle starts at 0 from the vehicle speed 0, the intersection of the vehicle speed v and the accelerator opening degree θ normally exists in the EV travel region, so the hybrid ECU 600 determines the drive motor 20 as a drive force source.
[0046]
When the drive motor 20 is selected as the driving force source and the vehicle moves forward with the shift positions D, M, and B, the transmission ECU 620 releases both the first and second clutches C1 and C2 and engages the brake B. This establishes the low-speed forward mode “1st”. Hybrid ECU 600 controls inverter 220 to cause drive motor 20 to output the required torque obtained from accelerator opening θ and vehicle speed v. Alternatively, when the operation state of the fuel cell 200 is unstable, the changeover switch 240 is controlled to connect the power supply line from the inverter 230 and the stator 22 of the drive motor 20. Hybrid ECU 600 controls inverter 230 to output the required torque obtained from accelerator opening θ and vehicle speed v to drive motor 20 to start the vehicle. After the vehicle starts moving, as the vehicle speed increases within the EV travel range, hybrid ECU 600 sequentially calculates the optimum gear ratio, and realizes the calculated gear ratio via transmission ECU 620. In the present embodiment, a creep torque in the forward direction is generated by the drive motor 20 when the vehicle is stopped. If sufficient power cannot be supplied to the drive motor 20 due to a shortage of fuel in the fuel cell 200 or a decrease in the storage amount SOC of the battery 210, the auxiliary drive motor 17 is driven by the engine 10 as a generator. The generated electric power is stored in the battery 210 and the driving motor 20 is operated.
[0047]
The gear ratio in the low speed forward mode “1st” is 1 / ρ1 (ρ1 is the gear ratio of the first planetary gear unit 31 (= the number of teeth of the first sun gear S1 / the number of teeth of the ring gear R)) and is relatively large and has a large torque. Since amplification is obtained, combined with a large gear ratio of the CVT 40, practically satisfactory creep torque and start performance can be obtained. In this embodiment, ρ1 <ρ2, and the speed ratio 1 / ρ1 is larger than the absolute value | 1 / ρ2 | of the speed ratio when the first clutch C1 is engaged and the engine 10 is used for reverse travel. A large torque amplifying action can be obtained.
[0048]
When shifting from the low-speed forward mode “1st” to the high-speed forward mode “2nd” by the engine 10, the hybrid ECU 600 releases the brake B while engaging the second clutch C <b> 2 via the transmission ECU 620, for example. The device 30 is rotated integrally, and the first clutch C1 is engaged after the rotation speed of the engine 10 is synchronized with the second sun gear S2, and then the power supply to the drive motor 20 is stopped to make it unloaded. .
[0049]
The transmission ECU 620 engages both the first and second clutches C1 and C2 and releases the brake B, whereby an assist mode with a transmission gear ratio of 1 that travels using both the engine 10 and the drive motor 20 as drive power sources is provided. “2nd (assist)” is established. The transmission ECU 620 releases the first clutch C1 and the brake B and engages the second clutch C2, and regenerative braking mode with a gear ratio of 1 that generates braking force while charging by regeneratively controlling the driving motor 20 Establish "2nd (regeneration)".
[0050]
When the drive motor 20 is selected as the drive force source and the vehicle moves backward with the shift position set to the R position, the transmission ECU 620 releases both the first and second clutches C1 and C2 and engages the brake B at a low speed. Establish reverse mode "low speed (motor)". In the low speed reverse mode, the hybrid ECU 600 generates reverse rotation torque in the drive motor 20, thereby generating reverse creep torque when the vehicle is stopped. Hybrid ECU 600 causes the vehicle to start backward by increasing the reverse rotation torque of drive motor 20 as the amount of accelerator depression increases. The gear ratio at this time is relatively large at 1 / ρ1, and a large torque amplification is obtained. Therefore, in combination with the large gear ratio of the CVT 40, a practically satisfactory creep torque and start performance are obtained.
[0051]
When shifting from the low speed reverse mode “low speed (motor)” to the high speed reverse mode “high speed” by the engine 10, the hybrid ECU 600 starts the engine 10 and engages the first clutch C1 via the transmission ECU 620. Later, the power supply to the drive motor 20 is stopped to bring it into a no-load state.
[0052]
During EV travel, the auxiliary machine 14 is driven by an auxiliary machine driving motor 17. The hybrid ECU 600 releases the electromagnetic clutch 16 to disconnect the engine 10 from the accessory drive system, and controls the changeover switch 240 to connect the power supply line from the inverter 220 and the power input line of the accessory drive motor 17. Connecting. The point that the battery 210 is used as a power source as needed is the same as in the case of the drive motor 20.
[0053]
When either the vehicle speed v or the accelerator opening θ is out of the EV travel range, that is, when entering the engine travel range, the hybrid ECU 600 determines switching of the drive power source from the drive motor 20 to the engine 10. Simultaneously with this determination, the hybrid ECU 600 temporarily stops the auxiliary machine drive motor 17 and turns on (engages) the electromagnetic clutch 16 to connect the crankshaft 11 and the auxiliary machine drive motor 17 via the timing belt 15. .
[0054]
Hybrid ECU 600 drives auxiliary machine drive motor 17 to increase the engine speed to the starting speed, and requests engine ECU 610 to perform start control. The engine ECU 610 controls an injector, an igniter (not shown) and the like as required to start explosion combustion of the engine 10.
[0055]
When the engine 10 is selected as the driving force source and the vehicle moves forward with the shift positions D, M and B, the transmission ECU 620 connects both the first and second clutches C1 and C2 and releases the brake B. Thus, the high speed forward mode “2nd” with a gear ratio of 1 is established. At the time of transition from the EV travel range, the first clutch C1 is engaged when the rotational speed of the engine 10 is synchronized with the rotational speed of the planetary gear device 30.
[0056]
Further, the transmission ECU 620 establishes the engine low speed forward mode “2nd (low speed)” in which the engine can start by slipping the first clutch C1, engaging the second clutch C2, and releasing the brake B. To do. When the vehicle starts in the engine low speed forward mode, the transmission ECU 620 gradually brings the first clutch into the fully engaged state as the vehicle speed increases.
[0057]
When the engine 10 is selected as the driving force source and the vehicle moves backward in which the shift position is the R position, the transmission ECU 620 engages the first clutch C1 and the brake B and releases the second clutch C2, so that the gear ratio is increased. The high speed reverse mode “high speed” of 1 / ρ2 (ρ2 is the gear ratio of the second planetary gear device 32 (= the number of teeth of the second sun gear S2 / the number of teeth of the ring gear R)) is established.
[0058]
Similarly to the forward movement, if the first clutch C1 is slip-engaged, an engine low-speed reverse mode “low-speed (engine)” capable of starting the engine can be established. Further, when the shift position takes the N position, the transmission ECU 620 releases both the first and second clutches C1 and C2 and engages the brake B to thereby transmit power from the engine 10 to the planetary gear unit 30. Block transmission.
[0059]
When the engine is running, hybrid ECU 600 requests engine ECU 610 to output the vehicle request torque obtained from accelerator opening θ and vehicle speed v. Based on a request from hybrid ECU 600, engine ECU 610 controls an operating state of engine 10 by controlling an injector, an igniter (not shown), and the like.
[0060]
Note that the hybrid vehicle control apparatus according to the present embodiment causes the engine 10 to operate at the operating point on the optimum fuel consumption curve L1 shown in FIG. FIG. 9 is an explanatory diagram showing a map of the fuel consumption priority region (optimum fuel consumption curve L1) used for determining the operating point of the engine 10 in this embodiment. In FIG. 9, the optimum fuel consumption curve L1 is a characteristic line using torque and engine speed as parameters, and shows an equal fuel consumption curve L2 that connects points where fuel consumption becomes equal and a point where outputs of the engine 10 become equal. It is determined from the iso-output curve L3.
[0061]
Hybrid ECU 600 calculates an optimum gear ratio based on vehicle speed v and accelerator opening θ, and realizes the calculated gear ratio via transmission ECU 620. Even when the engine is running, if an increase in vehicle request torque is requested, a control process described later is executed.
[0062]
When the engine is running, the auxiliary machine 14 is driven by the driving force of the engine 10. That is, the driving force output from the crankshaft 11 is transmitted to the auxiliary machine 14 via the timing belt 15.
[0063]
Next, a driving force source control process in the hybrid vehicle control device according to the present embodiment, which is executed during vehicle acceleration during engine 10 travel, will be described with reference to FIGS. 10 and 11. FIG. 10 is a flowchart showing a processing routine of a driving force source control process executed in the hybrid vehicle control apparatus according to this embodiment. FIG. 11 is an explanatory diagram showing a map used for obtaining the required torque from the accelerator opening.
[0064]
Hybrid ECU 600 obtains accelerator opening θ detected by accelerator opening sensor 74 (step S100). The hybrid ECU 600 calculates the required torque Treq from the accelerator opening θ using the map shown in FIG. 11 using the detected accelerator opening θ (step S110). In the present embodiment, for ease of explanation, the required torque Treq is calculated based only on the accelerator opening θ, but in addition to this, the torque required to drive the auxiliary machine 14 and the auxiliary machine drive Torque or the like required for generating electric power by driving the motor 17 can be reflected in the required torque Treq.
[0065]
Hybrid ECU 600 determines whether or not drive motor 20 is in a normally operable state (step S120), and determines that drive motor 20 is in a normally operable state (step S120). : Yes), the methanol remaining amount Frem that is the fuel for the fuel cell is acquired from the methanol remaining amount sensor 76, and it is determined whether or not the acquired methanol remaining amount Frem is equal to or larger than the predetermined value Fref (step S130).
[0066]
When hybrid ECU 600 determines that the remaining amount of methanol Frem ≧ Fref (step S130: Yes), torque difference ΔT between required torque Treq and current torque Tcur is equal to or less than maximum torque Tmgmax that can be output by drive motor 20. It is determined whether or not (step S140). This is because when the torque difference ΔT exceeds the maximum torque Tmgmax that can be output by the drive motor 20, it is impossible to output the required torque Treq only by the drive motor 20. In such a case, the drive motor 20 can be used by operating the engine 10 as will be described later.
[0067]
When the hybrid ECU 600 determines that the torque difference ΔT is equal to or less than the maximum torque Tmgmax that can be output by the drive motor 20 (step S140: Yes), the engine efficiency Enef is driven as a driving force source that outputs the required torque Treq. It is determined whether the motor efficiency is higher than the motor efficiency Mgef (step S150). That is, it is determined which of the engine 10 and the drive motor 20 outputs the best energy efficiency when the torque difference between the required torque Treq and the current torque Tcur is output. This also contributes to an improvement in energy efficiency of the entire vehicle.
[0068]
Details of such determination processing will be described with reference to FIG. FIG. 12 is an explanatory diagram showing energy efficiency of the engine 10 and the drive motor 20 with respect to torque. In FIG. 12, the energy efficiency Enef of the engine 10 is indicated by an energy efficiency curve L10, and the energy efficiency Mgef of the drive motor 20 is indicated by an energy efficiency curve L20.
[0069]
The energy efficiency Enef of the engine 10 can be defined by the following equation (1), for example.
Enef = fuel efficiency x engine efficiency x drive efficiency (1)
Here, the fuel efficiency is, for example, the amount of heat that can be generated by burning a predetermined amount of gasoline fuel. The engine efficiency is, for example, conversion efficiency that can extract heat generated by combustion of gasoline fuel as torque (output). The driving efficiency is, for example, an efficiency in consideration of electric power (loss) required when pumping up gasoline fuel in a gasoline tank and injecting it into an engine cylinder with an injector.
[0070]
The energy efficiency Mgef of the drive motor 20 can be defined by the following equation (2), for example.
Mgef = fuel efficiency x motor efficiency x drive efficiency (2)
Here, the fuel efficiency is, for example, the amount of electric power that can be generated from a predetermined amount of methanol fuel. The drive efficiency is an efficiency for converting electric power generated from methanol fuel into electric power for driving a motor, that is, inverter efficiency and power transmission efficiency. The motor efficiency is, for example, a ratio (efficiency) at which converted electric power can be extracted as torque (output).
[0071]
It is assumed that the maximum torque that can be output by the drive motor 20 is Tmgmax. Therefore, in the region where the required torque is less than or equal to the maximum torque Tmgmax of the drive motor 20, the drive motor 20 is used as a drive force source in principle, except for exceptions such as insufficient methanol fuel remaining.
[0072]
It is assumed that the current torque Tcur currently output by the engine 10 is A, the value of the first example corresponding to the required torque Treq is B, and the value of the second example is C. When the required torque Treq takes the first value B, the energy efficiency Enef of the engine 10 at the point B, the energy efficiency Mgef of the drive motor 20 when outputting the torque difference ΔT1 between the current torque Tcur and the required torque Treq are obtained. In comparison, the energy efficiency when the driving motor 20 is used as a driving force source is higher. Therefore, hybrid ECU 600 selects drive motor 20 as a drive force source.
[0073]
On the other hand, when the required torque Treq takes the second value C, the energy efficiency Mgef of the drive motor 20 at the time of outputting the torque difference ΔT2 between the energy efficiency Enef of the engine 10 at the point C, the current torque Tcur, and the required torque Treq. If the engine 10 is used as a driving force source, the energy efficiency becomes higher. Therefore, hybrid ECU 600 selects engine 10 as a driving force source. Further, the torque difference ΔT is output by the engine 10 even when the required torque Treq fluctuates exceeding the maximum torque Tmgmax that can be output by the drive motor 20.
[0074]
Returning to FIG. When the hybrid ECU 600 determines that the energy efficiency Enef of the engine 10 is higher than the energy efficiency Mgef of the drive motor 20 as a result of the calculation (step S150), the target throttle corresponding to the required torque is determined from the map shown in FIG. The valve opening θst is obtained, and throttle valve opening θs = target throttle valve opening θst is set (step S160). The hybrid ECU 600 supplies the required amount of fuel to the engine 10 through the injector together with the opening degree control of the throttle valve 13. Note that auxiliary load driving torque may be added to the required torque.
[0075]
When it is determined in step S120 that an abnormality has occurred in the drive motor 20 (step S120: No), and when it is determined in step S130 that the remaining amount of methanol Frem <Fref (step S130: No), since the drive motor 20 cannot be operated, the hybrid ECU 600 executes the process of step S160. When it is determined in step S140 that the torque difference ΔT is larger than the maximum torque Tmgmax that can be output by the drive motor 20 (step S140: No), the required torque Treq is output only by the drive motor 20. Since this is not possible, hybrid ECU 600 executes step S160.
[0076]
Hybrid ECU 600 executes control to change the gear ratio of CVT 40 via transmission ECU 620 after executing valve opening control of throttle valve 13 (step S170), and ends this processing routine. As is apparent from FIG. 9, when the operating point on the optimum fuel consumption curve L1 is selected as the operating point of the engine 10, when the torque is determined, the engine speed is uniquely determined and the torque increases. This will increase the engine speed. Therefore, since it is necessary to match the vehicle speed immediately after the start of control with the current vehicle speed, the speed of the CVT is controlled to reduce the engine speed (engine speed) to the current vehicle speed.
[0077]
When hybrid ECU 600 determines in step S140 that the energy efficiency Mgef of drive motor 20 is equal to or higher than the energy efficiency Enef of engine 10 (step S150: No), hybrid ECU 600 increases the amount of control current for drive motor 20. Then, the drive motor 20 outputs the torque difference ΔT between the required torque Treq and the current torque Tcur (step S180), and the processing routine is terminated.
[0078]
As described above, according to the control apparatus for a hybrid vehicle according to the present embodiment, the torque difference ΔT between the required torque Treq of the vehicle and the current torque Tcur is determined from the engine 10 or the drive motor 20 with high energy efficiency. Since the power is output by the power source, the engine 10 and the drive motor 20 can be operated in a state of high energy efficiency. Therefore, the fuel consumption of the engine 10 and the fuel consumption of the fuel cell 200 can be reduced, and the energy efficiency of the entire vehicle can be improved.
[0079]
Further, in the conventional hybrid vehicle in which the secondary battery is used as the power source of the drive motor, it is necessary to charge the secondary battery by operating the generator by the output of the engine. Since the control device uses the fuel cell 200 as the power source of the drive motor 20, the engine 10 can be operated at the most efficient operating point without considering the charging of the secondary battery. In conventional hybrid vehicles, even if the engine can be driven at the operating point on the optimal fuel consumption curve, the energy efficiency of the engine is not taken into account, and the fuel consumption of the engine is reduced to the optimal value. It could not be said. On the other hand, according to the hybrid vehicle control device of the present embodiment, not only can the engine 10 be driven at the driving point on the optimal fuel consumption curve L1, but also among the driving points on the optimal fuel consumption curve L1. Thus, the engine 10 can be operated at an energy efficient operation point.
[0080]
As mentioned above, although the hybrid vehicle control apparatus according to the present invention has been described based on the embodiments, the above-described embodiments are for facilitating understanding of the present invention and do not limit the present invention. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.
[0081]
For example, in the above embodiment, only one of the engine 10 and the driving motor 20 is used as a driving force source for outputting the torque difference ΔT between the required torque Treq and the current torque Tcur. The torque difference ΔT may be output using both the motors 20 for driving as driving force sources. As can be seen from FIG. 12, the energy efficiency Enef of the engine 10 increases as the torque increases. Therefore, for example, in FIG. 9, while maintaining the operating point of the engine 10 at Pa, the driving motor 20 does not output the torque difference ΔT between the required torque Treq and the current torque Tcur, and the operating point of the engine 10 is changed to Pb. After that, if the insufficient torque difference is output by the driving motor 20, the energy efficiency of the entire vehicle may be the best.
[0082]
When the required torque Treq takes a value B ′ indicated by a two-point difference line in FIG. 12, the torque difference ΔT between the required torque Treq and the current torque Tcur exceeds the maximum torque Tmgmax of the drive motor 20. Even in such a case, a part of the torque difference ΔT can be output by the engine 10 and the remaining torque difference ΔT can be output by the driving motor 20. For example, in the vehicle travel region where the energy efficiency Mgef of the drive motor 20 is higher than the energy efficiency Enef of the engine 10, the engine 10 outputs the torque A ′ and the torque with B ′ that is the required torque Treq. By making the difference ΔT the maximum torque Tmgmax of the drive motor 20 and outputting the maximum torque Tmgmax by the drive motor 20, the energy efficiency of the entire vehicle can be improved.
[0083]
In the above embodiment, the engine 10 is operated at the operation point on the optimum fuel consumption curve L1, but, for example, the engine 10 may be operated on a fuel consumption curve of 90% with respect to the optimum fuel consumption curve. Even in such a case, considering the energy efficiency, the energy efficiency can be higher than when the engine 10 is operated at the operating point on the optimum fuel consumption curve without considering the energy efficiency.
[0084]
Further, the parameters defining the energy efficiency Enef of the engine 10 and the energy efficiency Mgef of the driving motor 20 in the above embodiment are merely examples, and the energy efficiency Enef and Mgef may be defined using other parameters. .
[0085]
In the above embodiment, methanol is used as the fuel for the fuel cell 200, but other raw materials containing hydrogen atoms such as alcohols, hydrocarbons, ethers, and aldehydes can be used.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a vehicle to which a hybrid vehicle control device according to an embodiment can be applied.
2 is a block diagram showing a schematic configuration of a changeover switch 240 in the vehicle shown in FIG. 1. FIG.
FIG. 3 is a block diagram illustrating a control circuit configuration of a control apparatus for a hybrid vehicle according to the present embodiment.
4 is a block diagram showing the input / output signal relationship of the control unit 60. FIG.
FIG. 5 is an explanatory diagram showing a map used to determine which of the engine 10 and the driving motor 20 is used as a driving force source when the vehicle moves forward based on the vehicle speed, the output torque (accelerator opening), and the shift position. It is.
FIG. 6 is an explanatory diagram showing a map used to determine which of the engine 10 and the driving motor 20 is used as a driving force source when the vehicle is driven backward based on the vehicle speed, the output torque (accelerator opening), and the shift position. It is.
FIG. 7 is an explanatory diagram showing the relationship between the engagement states of the clutches C1 and C2 and the brake B and the shift state of the planetary gear device 30, and is classified according to the driving force source, the shift position, and the like.
FIG. 8 is an explanatory diagram showing an example of a shift lever position arrangement.
FIG. 9 is an explanatory diagram showing a map of a fuel consumption priority region (optimum fuel consumption curve L1) used for determining an operation point of the engine in the present embodiment.
FIG. 10 is a flowchart showing a processing routine of a driving force source control process executed in the hybrid vehicle control apparatus according to the embodiment.
FIG. 11 is an explanatory diagram showing a map used for obtaining a required torque from an accelerator opening.
12 is an explanatory diagram showing energy efficiency of the engine 10 and the drive motor 20 with respect to torque. FIG.
FIG. 13 is an explanatory diagram showing a map used for obtaining the throttle valve opening from the required torque.
[Explanation of symbols]
10 ... Engine
11 ... Crankshaft
12 ... Accelerator pedal
13 ... Throttle valve
14 ... Auxiliary machine
15. Timing belt
16 ... Multi-plate electromagnetic clutch
17 ... Auxiliary drive motor
18 ... Damper
20 ... Drive motor
21 ... Rotor
22 ... Stator
23 ... Rotating shaft
30 ... Planetary gear unit
31 ... 1st planetary gear set
32. Second planetary gear unit
40 ... Continuously variable automatic transmission (CVT)
41 ... Input side pulley
42 ... Output pulley
43 ... Steel belt
50 ... Drive shaft
51. Differential gear
52 ... Axle
53 ... wheel
60 ... Control unit
70 ... Engine speed sensor
71 ... Resolver
72 ... Vehicle speed sensor
73 ... Shift position sensor
74: accelerator opening sensor
75 ... Throttle valve opening sensor
76 ... Methanol remaining amount sensor
77 ... SOC sensor
110 ... Methanol tank
200: Fuel cell
210 ... Battery
220 ... Inverter
230 ... Inverter
240 ... changeover switch
600 ... Hybrid ECU
610 ... Engine ECU
620 ... Transmission ECU
C1 ... 1st clutch
C2 ... Second clutch
P1 ... Common pinion gear
P2 ... Independent pinion gear
R ... Ring gear
S1 ... 1st sun gear
S2 ... Second sun gear

Claims (8)

As a driving force source, a heat engine that generates driving force by combustion of fuel and an electric motor that generates electric power by consuming electric power from a fuel cell that consumes fuel for fuel cell to generate electric power are provided as a driving force source. When a heat engine is used, it is a control device for a hybrid vehicle that operates the heat engine in an operation region where fuel efficiency is optimal,
Requested torque calculating means for calculating required torque required for the vehicle;
Torque difference calculating means for obtaining a torque difference between the current torque of the heat engine and the required torque in an operation region where the fuel efficiency is optimal;
Driving force source selection means for selecting a driving force source capable of generating the calculated torque difference with the highest energy efficiency from one of the heat engine and the electric motor or a combination of both;
When the heat engine is selected as a drive force source by the drive force source selection means, the drive force source that outputs the torque difference by operating the heat engine in an operation region where the fuel efficiency is optimal. Control means ,
The energy efficiency is
The heat engine includes a fuel efficiency related to the amount of heat that can be generated by the fuel, a heat engine efficiency that is an efficiency in converting the generated heat amount into torque, and a drive efficiency associated with the operation of the heat engine,
For the electric motor, control of the hybrid vehicle including fuel efficiency related to the amount of electric power that can be generated from the fuel for the fuel cell, electric motor efficiency that is efficiency when converting the electric power into torque, and drive efficiency that accompanies the operation of the electric motor apparatus. In the hybrid vehicle control device according to claim 1,
The control apparatus for a hybrid vehicle, wherein the driving force source control means outputs the torque difference by the electric motor when the electric motor is selected as the driving force source by the driving force source selection means. In the hybrid vehicle control device according to claim 1,
The driving force source control means, when the combination of the heat engine and the electric motor is selected as a driving force source by the driving force source selection means, the heat engine is operated in an operating region where the fuel consumption is optimal. A hybrid characterized in that the fuel consumption priority torque smaller than the required torque is generated by driving and the torque difference is output by causing the motor to output an insufficient torque difference between the required torque and the fuel efficiency priority torque. Vehicle control device. In the hybrid vehicle control device according to claim 3,
The control apparatus for a hybrid vehicle, wherein the fuel efficiency priority torque is a torque that is closest to the required torque and that can be output by the heat engine in an operation region where the fuel efficiency is optimal. The hybrid vehicle control device according to any one of claims 1, 3, and 4 further includes:
A transmission that decelerates and transmits the engine rotational speed of the heat engine by changing a gear ratio;
A hybrid vehicle control device comprising: a transmission control means for controlling a gear ratio of the transmission so as to match an engine rotational speed of the heat engine at the time of outputting the required torque or the fuel efficiency priority torque with the current vehicle speed of the vehicle. In a control method for a hybrid vehicle comprising a heat engine that consumes combustion fuel to generate driving force and an electric motor that consumes electric power from a fuel cell and generates driving force as a driving force source,
Calculate the required torque required for the vehicle,
During the operation of the heat engine, the heat engine is operated on an optimal fuel consumption curve that optimizes fuel consumption of the heat engine expressed as a characteristic line of engine speed and output torque of the heat engine. ,
Obtaining a torque difference between the current torque of the heat engine at the first operating point on the optimum fuel consumption curve and the required torque;
A driving force source capable of generating the calculated torque difference with the highest energy efficiency is selected from one or a combination of the heat engine and the electric motor;
When you select the heat engine as a driving force source comprises a thereby output the torque difference by operating the heat engine at the second operating point on the optimal fuel consumption curve corresponding to the required torque ,
The energy efficiency is
The heat engine includes a fuel efficiency related to the amount of heat that can be generated by the fuel, a heat engine efficiency that is an efficiency in converting the generated heat amount into torque, and a drive efficiency associated with the operation of the heat engine,
For the electric motor , control of the hybrid vehicle including fuel efficiency related to the amount of electric power that can be generated from the fuel for the fuel cell, electric motor efficiency that is efficiency when converting the electric power into torque, and drive efficiency that accompanies the operation of the electric motor Method. The hybrid vehicle control method according to claim 6,
When the electric motor is selected as a driving force source, the torque difference is output by the electric motor. The hybrid vehicle control method according to claim 6,
When a combination of the heat engine and the electric motor is selected as a driving force source, the heat engine is operated at a third operating point on the optimum fuel efficiency curve corresponding to a fuel efficiency priority torque smaller than the required torque. The hybrid vehicle control method further comprising: outputting the fuel efficiency priority torque and outputting the torque difference by causing the electric motor to output an insufficient torque difference between the required torque and the fuel efficiency priority torque.

Images