JP2013139226A - Control apparatus of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve startability of an engine when the reboot of a vehicle system is requested in the travel after stopping the vehicle system in a vehicle.SOLUTION: When the engine is started again after the hybrid system is stopped in the travel, the restriction of the output torque of a second motor generator MG 2 (torque that controls the torque transmitted to the driving wheel) is eased, and the electric power is consumed by the second motor generator MG 2 to the extent that the restriction is eased. Exceeding of the input limit Win of the battery can be controlled by such a control, and the output torque of the first motor generator MG 1 can be enlarged. As a result, the motoring torque at the engine startup in the travel can be enlarged, while keeping the power balance, and the startability of the engine can be improved.

Description

  The present invention relates to a control device for a hybrid vehicle.

  In recent years, from the viewpoint of environmental protection, it has been desired to reduce exhaust gas emissions from engines (internal combustion engines) mounted on vehicles and to improve fuel consumption rate (fuel consumption). A hybrid vehicle equipped with a hybrid system including an engine and an electric motor (motor generator) is known as a driving force source.

  One known hybrid system mounted on a vehicle includes, for example, an engine, a first motor generator, a second motor generator, and a planetary gear mechanism (differential mechanism) constituting a power split mechanism. ing. Specifically, the engine output shaft (crankshaft) is connected to the planetary carrier of the power split mechanism, the first motor generator MG1 is connected to the sun gear, and the reduction mechanism (for example, a planetary gear mechanism) is configured to the ring gear. ) Is connected to the second motor generator MG2, and the ring gear is connected to the drive wheels via a reduction mechanism, a differential device, or the like. In such a hybrid system, when the engine is started while the vehicle is running, the engine is motored (cranked) by the first motor generator, and transmitted to the drive wheels as the first motor generator is driven. Torque (reaction force) is controlled by the output torque of the second motor generator (reaction force cancellation), and the engine is started.

  The hybrid vehicle is provided with a power switch for switching between starting and stopping of the hybrid system (vehicle system). For example, when the power switch is operated with the brake pedal operated, the hybrid system Is supposed to start. Further, when the power switch is operated during traveling (while the hybrid system is being activated), the hybrid system is stopped.

  In the hybrid vehicle, there is a technique described in Patent Document 1 below as a technique related to starting / stopping the hybrid system. In the technique described in Patent Document 1, when the vehicle start / stop switch is operated to a position where the engine is stopped (Off position or Ready-Off) during high-speed traveling, the battery is prohibited by stopping the engine. The battery is protected by preventing the amount of discharge from exceeding the upper limit discharge amount.

JP 2007-216833 A JP 2007-023919 A

  By the way, in the above-described hybrid vehicle, when a driver or the like mistakenly performs a stop operation (IG-Off operation during travel) of the hybrid system (vehicle system) during travel, before the travel of the hybrid vehicle stops ( It is conceivable that the driver performs a restart operation (IG-On during traveling) of the hybrid system during inertial traveling. When the system is restarted, it may be required to start the engine.

  However, the engine may not be restarted when the hybrid system is restarted while the vehicle is running. The reason for this will be described. First, when starting the engine while the vehicle is running, the operating point of the first motor generator that performs motoring is in the negative rotation region (power generation region) (see FIG. 4), so the first motor generator functions as a generator. . When the sum of the power generated by the first motor generator and the power consumed by the second motor generator exceeds the input limit Win of the battery (when the power balance cannot be maintained), the first motor generator Since the output torque is limited, the engine may not be restarted due to insufficient motoring torque.

  The technique described in Patent Document 1 is a technique for prohibiting forced engine stop when the vehicle start / stop switch is operated to a position where the engine is stopped during high-speed travel. The case where the IG-On is operated after the engine is stopped is not taken into consideration.

  The present invention has been made in consideration of such circumstances, and can improve the startability of the engine when a restart request of the vehicle system is made after the stop of the vehicle system while the vehicle is running. An object of the present invention is to provide a control device for a hybrid vehicle.

  The present invention relates to an engine that outputs a driving force for traveling a vehicle, a first motor generator and a second motor generator that can input and output power to a power transmission path from an output shaft of the engine to a driving wheel of the vehicle. A power storage device capable of inputting and outputting electric power between the first motor generator and the second motor generator, and motoring the engine by the first motor generator when starting the engine, It is premised on a control device for a hybrid vehicle capable of executing control for suppressing torque transmitted to the drive wheels by motoring by the first motor generator with output torque of the second motor generator.

  In such a hybrid vehicle control device, when the vehicle system is stopped (hybrid system is stopped) while the vehicle is running, the vehicle system is restarted before the vehicle stops. When starting the engine, the technical feature is that the restriction on the output torque of the second motor generator (torque that suppresses torque transmitted to the drive wheels) is relaxed compared to when starting the engine during normal travel. .

  In the present invention, “when the engine is started during normal travel” means that the engine 1 is started when the engine start condition is satisfied (EV travel condition is not satisfied) and the engine 1 is started (during EV travel) ( At start-up during Ready-On).

  The “limit of the output torque of the second motor generator when starting the engine during normal driving” means that the output torque of the second motor generator (torque transmitted to the drive wheels is suppressed when starting the engine during driving). This is a process of limiting (upper limit guard) the torque transmitted to the drive wheels so that the driving force of the vehicle does not increase (the vehicle speed increases).

  In addition, for example, the normal running engine start-up described above may be performed with respect to the processing for relaxing the restriction on the output torque of the second motor generator MG2 (the suppression torque that suppresses the torque transmitted to the drive wheels) when the engine is running. When the limit value that limits the output torque of the second motor generator at the time is the first upper limit value, the second upper limit value that is larger than the first upper limit value is used to restart the hybrid system while the vehicle is running (engine By limiting the output torque of the second motor generator at the time of restart), a process of relaxing the limit of the output torque of the second motor generator at the time of restarting while the vehicle is running can be mentioned.

  According to the present invention, when the engine is restarted after the vehicle system is stopped during traveling, the output torque of the second motor generator (the suppression torque that suppresses the torque transmitted to the drive wheels) is limited. (The torque limit value is relaxed), the second motor / generator can consume the power (the power generated by the first motor / generator) as much as the torque limit is relaxed. Exceeding the limit Win can be suppressed. As a result, when the engine is running, the torque that suppresses the torque transmitted to the drive wheels slightly exceeds that during normal control, but the torque limit of the first motor generator can be expanded (relaxed). While maintaining the power balance (Win), the motoring torque can be secured, and the restartability of the engine is improved. As a result, it may be possible to start the engine even in a region where the engine cannot be started under conventional control (a region where torque suppression transmitted to the drive wheels and power balance are not compatible).

  As described above, the startability of the engine at the time of restart after stopping the running vehicle system is improved, so that the driver can easily recognize that the restart operation of the vehicle system has been accepted. When the engine is started, noise and vibration are generated, so that the driver can easily recognize that the start operation has been accepted.

  In the present invention, when a braking force applying means (braking device) for applying a mechanical braking force to the vehicle is provided, and the vehicle system is stopped while the vehicle is running, the vehicle system is requested to restart. Further, when starting the engine, the braking force applying means increases the driving force (transmitted to the driving wheel) that is increased by the relaxation of the output torque of the second motor generator (torque that suppresses the torque transmitted to the driving wheel). The braking force may be applied to the vehicle so as to cancel the excess torque). By adopting such a configuration, when the engine is started while the vehicle is running, the power balance at the time of starting the engine can be reduced while protecting the torque that suppresses the torque transmitted to the drive wheels (hereinafter also referred to as “suppressed torque”). It is possible to achieve both engine startability.

  In the present invention, when a restart of the vehicle system is requested after the vehicle system is stopped while the vehicle is running, the auxiliary equipment such as an air conditioner (air conditioner) mounted on the vehicle is forced. It may be driven to consume power. By adopting such a configuration, it is possible to relax the battery input limit Win at the time of restarting the engine during traveling, and it is possible to increase the motoring torque by the first motor generator, thereby starting the engine. Improves.

  In the present invention, when the vehicle system is stopped while the vehicle is running and the vehicle system is requested to be restarted, the suppression torque (the torque transmitted to the drive wheels) by the second motor generator described above. If the torque to be suppressed cannot be ensured, the engine start may be stopped.

  In the present invention, an operation unit that receives operations for starting and stopping the vehicle system is provided, and the vehicle stops after the rider performs an operation to stop the vehicle system using the operation unit while the vehicle is running. If the occupant performs an operation for starting the vehicle system using the operation unit (when a restart is requested), the control at the time of starting the engine (the suppression torque of the second motor generator) is performed. (Startup control including restriction relaxation) may be executed. The passenger includes a driver.

  By adopting such a configuration, after the stop operation of the vehicle system is performed by the passenger while the vehicle is traveling, the engine is started when the start operation of the vehicle system is performed by the passenger before the vehicle stops. Therefore, the passenger (driver) can easily recognize that the activation operation has been accepted.

  Further, in the present invention, an operation unit that receives operations for starting and stopping the vehicle system is provided, and after the signal for stopping the vehicle system is received from the operation unit during traveling of the vehicle, before the vehicle stops. When a signal for starting the vehicle system is received from the operation unit (when a restart request is made), the engine start control (start control including relaxation of restriction of the suppression torque by the second motor generator) is performed. It may be configured to execute.

  By adopting such a configuration, the startability of the engine is improved when the start operation of the vehicle system is performed before the vehicle stops after the stop operation of the vehicle system is performed while the vehicle is running. It becomes easier for the passenger (driver) to recognize that the activation operation has been accepted.

  Here, as a specific configuration of the present invention, a configuration in which a differential mechanism is provided in a power transmission path from the output shaft of the engine to the drive wheels of the vehicle can be exemplified. In this case, the differential mechanism is configured as follows. In other words, the operating mechanism is a planetary gear mechanism having a first rotating element (sun gear), a second rotating element (planetary carrier), and a third rotating element (ring gear) that can rotate differentially with each other. The rotating element is connected to the first motor generator, the second rotating element is connected to the engine, the third rotating element is connected to the second motor generator, and the differential state is controlled by the first motor generator. To be configured.

  According to the present invention, when the engine is started during traveling after the vehicle system is stopped during traveling, the limitation on the output torque of the second motor generator is relaxed. Can be improved.

It is a schematic structure figure showing an example of a hybrid vehicle to which the present invention is applied. It is a block diagram which shows the structure of control systems, such as ECU. It is a collinear diagram which shows the relative relationship of the rotational speed of each rotation element of a power split device. FIG. 4 is a collinear diagram showing a relative relationship between the rotational speeds of the rotating elements of the power split mechanism, and FIG. 4 shows a state when the engine is started while the vehicle is running. It is the schematic which shows the shift operation apparatus of the hybrid vehicle of FIG. It is a flowchart which shows an example of the control at the time of restart after a hybrid system stop while driving | running | working a vehicle. It is a flowchart which shows an example of control at the time of driving | running | working system starting.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an example of a vehicle to which the present invention is applied.

  The vehicle in this example is an FF (front engine / front drive) type hybrid vehicle HV, which is an engine (internal combustion engine) 1 that generates driving force for traveling the vehicle, and a first motor generator that mainly functions as a generator. MG1, a second motor generator MG2 mainly functioning as an electric motor, a power split mechanism 3, a reduction mechanism 4, a counter drive gear 51, a counter driven gear 52, a final gear 53, a differential device 54, front wheel axles (drive shafts) 61, 61, Front wheels (drive wheels) 6L and 6R, rear wheels (driven wheels: not shown), brake devices 7, 7 and an ECU (Electronic Control Unit) 100 are provided. By a program executed by the ECU 100 Control of hybrid vehicle of the present invention A device is realized.

  The ECU 100 includes, for example, an HV (hybrid) ECU, an engine ECU, a battery ECU, a brake ECU, and the like, and these ECUs are connected so as to communicate with each other.

  Next, components such as the engine 1, the motor generators MG1 and MG2, the power split mechanism 3, the reduction mechanism 4, and the ECU 100 will be described.

-Engine-
The engine 1 is a known power unit (internal combustion engine) that outputs power by burning fuel such as a gasoline engine or a diesel engine, and the throttle opening (intake air amount) of a throttle valve 13 provided in the intake passage 11. ), And the operation state such as the fuel injection amount and the ignition timing can be controlled. Further, the exhaust gas after combustion is discharged through the exhaust passage 12 to the outside air after being purified by an oxidation catalyst (not shown).

  For controlling the throttle valve 13 of the engine 1, for example, an optimum intake air amount (target intake air amount) corresponding to the state of the engine 1 such as the engine speed and the accelerator pedal depression amount (accelerator opening) of the driver is obtained. As described above, electronic throttle control for controlling the throttle opening is employed. In such electronic throttle control, the throttle opening sensor 103 is used to detect the actual throttle opening of the throttle valve 13, and the actual throttle opening is the throttle opening (target throttle opening at which the target intake air amount is obtained). ), The throttle motor 14 of the throttle valve 13 is feedback-controlled.

  The output of the engine 1 is transmitted to the input shaft 21 via the crankshaft (output shaft) 10 and the damper 2. The damper 2 is a coil spring type transaxle damper, for example, and absorbs torque fluctuations of the engine 1.

-Motor generator-
The first motor generator MG1 is an AC synchronous generator including a rotor MG1R made of a permanent magnet supported so as to be relatively rotatable with respect to the input shaft 21, and a stator MG1S wound with a three-phase winding. It functions as a generator and also as an electric motor (electric motor). Similarly, the second motor generator MG2 includes an AC synchronous generator including a rotor MG2R made of a permanent magnet supported so as to be relatively rotatable with respect to the input shaft 21, and a stator MG2S wound with a three-phase winding. It functions as an electric motor (electric motor) as well as a generator.

  As shown in FIG. 2, first motor generator MG <b> 1 and second motor generator MG <b> 2 are each connected to HV battery (power storage device) 300 via inverter 200. Inverter 200 is controlled by ECU 100, and regeneration or power running (assist) of each motor generator MG 1, MG 2 is set by the control of inverter 200. The regenerative power at that time is charged into the HV battery 300 via the inverter 200. In addition, driving power for each motor generator MG <b> 1, MG <b> 2 is supplied from the HV battery 300 via the inverter 200.

  The hybrid vehicle HV is equipped with an auxiliary battery (not shown) in addition to the HV battery 300. The auxiliary battery supplies power to the auxiliary equipment such as the ECU 100, various lamps, audio equipment, and an air conditioner (compressor). The auxiliary battery is connected to the HV battery 300 via a converter.

-Power split mechanism-
As shown in FIG. 1, the power split mechanism 3 revolves around a sun gear S3 (first rotating element) of an external gear that rotates at the center of a plurality of gear elements and rotates around its periphery while circumscribing the sun gear S3. An external gear pinion gear P3, an internal gear ring gear R3 (third rotation element) formed in a hollow ring so as to mesh with the pinion gear P3, and the pinion gear P3 are supported, and the planetary gear that rotates through the revolution of the pinion gear P3. It is comprised by the planetary gear mechanism which has carrier CA3 (2nd rotation element). Planetary carrier CA3 is connected to crankshaft (output shaft) 10 of engine 1 via input shaft 21 and damper 2. The sun gear S3 is integrally connected to the rotor MG1R (rotary shaft) of the first motor generator MG1. As a result, power can be input / output to / from the power transmission path from the crankshaft 10 of the engine 1 to the drive wheels 6L, 6R by the first motor generator MG1.

  The power split mechanism 3 transmits at least one driving force of the engine 1 and the second motor generator MG2 via a counter drive gear 51, a counter driven gear 52, a final gear 53, a differential device 54, and drive shafts 61 and 61. It is transmitted to the left and right drive wheels 6L, 6R.

FIG. 3 shows an alignment chart of the power split mechanism 3. In the collinear diagram of FIG. 3, the vertical axis Y1, the vertical axis Y2, and the vertical axis Y3 indicate the rotational speed of the sun gear S3 (MG1), the rotational speed of the planetary carrier CA3 (engine 1), and the ring gear R3, respectively. (Output) is an axis representing the rotation speed, and the vertical axis Y1, the vertical axis Y2, and the vertical axis Y3 are spaced apart from each other when the interval between the vertical axis Y1 and the vertical axis Y2 is “1”. And the vertical axis Y3 are set so as to be the gear ratio ρ (the number of teeth Z _{S of the} sun gear S3 / the number of teeth Z _{R of the} ring gear R3).

  In the power split mechanism 3 having such a configuration, the reaction force (torque) by the first motor generator MG1 is the sun gear S3 (reaction force) with respect to the output torque of the engine 1 input to the planetary carrier CA3 that is an input element. Is input to the element), a torque larger than the torque input from the engine 1 appears in the ring gear R3 which is an output element. In this case, the first motor generator MG1 functions as a generator.

  Further, when the rotational speed of the ring gear R3 (the rotational speed of the drive wheels 6L and 6R) is constant, the rotational speed of the engine 1 is continuously (null) by changing the rotational speed of the first motor generator MG1 up and down. Can be changed). For example, by controlling the drive of the first motor generator MG1, it is possible to execute control for setting the rotational speed of the engine 1 to the rotational speed with the best fuel efficiency. 3 indicates a state in which the rotational speed of the engine 1 decreases when the rotational speed of the first motor generator MG1 is lowered from the value indicated by the solid line.

  Further, as shown in the nomograph of FIG. 4, when the engine 1 is stopped while the hybrid vehicle HV is running, the first motor generator MG1 rotates in the reverse direction. From this state, the first motor generator MG1 is turned off. When the torque is output in the forward rotation direction by functioning as an electric motor, the torque in the direction of rotating the engine 1 forward acts on the engine 1 connected to the planetary carrier CA3. Therefore, the engine 1 can be started (motored) by the first motor generator MG1.

  When the engine 1 is started while the hybrid vehicle HV is running, the torque (reaction force) transmitted to the drive wheels 6L and 6R accompanying the motoring by the first motor generator MG1 is the output torque of the second motor generator MG2. At the same time, the control is performed to limit the output torque of the second motor generator MG2 (the torque that suppresses the torque transmitted to the drive wheels 6L and 6R).

  The limitation on the output torque (suppression torque) of the second motor generator MG2 is to suppress the output torque of the second motor generator MG2 (torque transmitted to the drive wheels 6L and 6R when the engine is started during normal traveling. In the process of limiting (upper limit guard) the output torque of the second motor generator MG2 so that the driving force of the hybrid vehicle HV does not increase (the vehicle speed increases due to the excess of the output torque of the second motor generator MG2). That is. The limit value (first upper limit value) of the output torque (suppression torque) of the second motor generator MG2 used when starting the engine during normal traveling is, for example, the parameter of the motoring torque (reaction torque) by the first motor generator MG1. Can be obtained using a map or the like created in advance by experiments and calculations.

  It should be noted that when the engine is started during normal traveling, the engine 1 is started when the EV traveling condition is not satisfied (engine starting condition is satisfied) during EV traveling (engine starting during Ready-On). Time).

  Here, in the present embodiment, as described later, after the hybrid system is stopped (IG-Off) during traveling, the engine is started when the hybrid system is restarted (restart request). Control that relaxes the restriction on the output torque of the second motor generator MG2 (torque that suppresses torque transmitted to the drive wheels 6L and 6R) compared to when the engine is running during normal travel (releasing the torque limit value) Control). The ECU 100 executes control related to the start of the engine 1 including the restriction relaxation control of the output torque of the second motor generator MG2.

  Note that, for example, the normal traveling described above is performed with respect to the processing for relaxing the restriction on the output torque of the second motor generator MG2 (the suppression torque for suppressing the torque transmitted to the drive wheels 6L and 6R) when the engine is started during traveling. When the torque limit value that limits the output torque of the second motor generator MG2 at the time of starting the middle engine is the first upper limit value, the hybrid system that is running the vehicle using the second upper limit value that is larger than the first upper limit value By limiting the output torque of the second motor generator at the time of restart (when the engine is restarted), the limit of the output torque of the second motor generator at the time of restart may be relaxed more than during normal control.

-Reduction mechanism-
As shown in FIG. 1, the reduction mechanism 4 is rotatably supported by an external gear sun gear S4 that rotates at the center of a plurality of gear elements and a planetary carrier (transaxle case) CA4, and circumscribes the sun gear S4. The planetary gear mechanism includes a pinion gear P4 that is an external gear that rotates, and a ring gear R4 that is an internal gear that is formed in a hollow ring so as to mesh with the pinion gear P4. The ring gear R4 of the reduction mechanism 4, the ring gear R3 of the power split mechanism 3, and the counter drive gear 51 are integrated with each other. Sun gear S4 is coupled to a rotor MG2R (rotating shaft) of second motor generator MG2 so as to rotate together. Thus, power can be input / output to / from the power transmission path from the crankshaft 10 of the engine 1 to the drive wheels 6L, 6R by the second motor generator MG2.

  The reduction mechanism 4 decelerates the driving force of the second motor generator MG2 at an appropriate reduction ratio. The reduced driving force is transmitted to the left and right drive wheels 6L and 6R via the counter drive gear 51, the counter driven gear 52, the final gear 53, the differential device 54, and the drive shaft 61.

-Brake device-
As shown in FIG. 1, the hybrid vehicle HV of this example decelerates the hybrid vehicle HV by braking the front wheels (drive wheels) 6L and 6R and the rear wheels (driven wheels: not shown). A mechanical brake device 7 for stopping is provided for each wheel. The brake device 7 is, for example, a disc brake, and includes a brake disc and a caliper incorporating a brake pad and a wheel cylinder.

  The hydraulic pressure of the wheel cylinder of each brake device 7 is controlled by a brake hydraulic pressure control device 70. The brake hydraulic pressure control device 70 controls each brake device 7 by controlling the brake hydraulic pressure from the master cylinder that operates according to the depression amount (the pedal stroke operation amount) of the brake pedal (not shown) and the master cylinder and the hydraulic pump. A brake actuator (hydraulic control circuit) that supplies the wheel cylinder is provided. The brake hydraulic pressure control device 70 is controlled by the brake ECU of the ECU 100.

  The brake ECU controls the brake hydraulic pressure control device 70 according to the depression amount and the depression acceleration of the brake pedal obtained from the output signal of the brake pedal sensor 110 (see FIG. 2), and supplies the hydraulic pressure supplied to each brake device 7. By controlling, the braking force of the hybrid vehicle HV is applied. The brake ECU executes various types of braking control such as ABS (anti-brake system) control, TRC (traction control), and VSC (attitude maintenance control) that are generally known. Furthermore, as will be described later, the brake ECU controls the brake hydraulic pressure control circuit 70 to restart the hybrid vehicle when the engine 1 is running while the vehicle is running (when the hybrid system is restarted while the vehicle is running). It is also possible to apply a braking force to the HV (the braking force to be applied can be variably controlled).

-Shift operation device-
The hybrid vehicle HV of this example is provided with a shift operation device 8 as shown in FIG. The shift operating device 8 is provided with a shift lever 81 that can be displaced. The shift operation device 8 of this example includes a drive range (D range) for forward travel, a brake range (B range) for forward travel with a large braking force (engine brake) when the accelerator is off, and a reverse range for reverse travel. (R range) and neutral neutral range (N range) are set, and the driver can displace the shift lever 81 to a desired range. Each position of the D range, B range, R range, and N range is detected by the shift position sensor 105. An output signal of the shift position sensor 105 is input to the ECU 100.

  Further, a P position switch 106 for setting a parking position (P position) for parking is provided in the vicinity of the shift lever 81. The P position switch 106 is a switch for switching the shift position between a parking position (P position) and a position other than parking (non-P position), and outputs an operation signal to the ECU 100 when operated by a driver. To do.

-Power switch-
The hybrid vehicle HV is provided with a power switch 107 (see FIGS. 2 and 5) for switching between starting and stopping of the hybrid system (vehicle system). The power switch 107 is, for example, a rebound type push switch, and the switch On and the switch Off are alternately switched each time a pressing operation is performed. Here, the hybrid system refers to running of the hybrid vehicle HV by executing various controls including operation control of the engine 1, drive control of the motor generators MG1 and MG2, and cooperative control of the engine 1 and the motor generators MG1 and MG2. It is a system to control.

  When the power switch 107 is operated by a user including a driver, the power switch 107 outputs a signal (IG-On command signal or IG-Off command signal) corresponding to the operation to the ECU 100. ECU 100 starts or stops the hybrid system based on a signal output from power switch 107 or the like.

  Specifically, when an IG-On command signal is input by operating the power switch 107 (IG-On operation), the ECU 100 activates the hybrid system. As a result, the vehicle can run. The state in which the vehicle can travel is a state in which the vehicle traveling can be controlled by a command signal from the ECU 100, and the hybrid vehicle HV can start and travel (Ready-On state) if the driver turns on the accelerator. . The Ready-On state includes a state where the engine 1 is stopped and the second motor generator MG2 can start and run the hybrid vehicle HV.

  ECU 100 stops the hybrid system when the power switch 107 is operated (for example, short-pressed), for example, when the hybrid system is activated and is in the P position when the vehicle is stopped.

  Furthermore, in the present embodiment, when the power switch 107 is operated (long press: for example, 3 seconds) while the hybrid vehicle HV is running (while the hybrid system is activated), the hybrid system is stopped (IG-Off). It is possible. Further, when the power switch 107 is operated (IG-On operation) after the hybrid system is stopped during such vehicle travel (after IG-Off), the restart request for the hybrid system (IG- The hybrid system can be restarted in response to (Off → IG-On), and the engine 1 is restarted when the system is restarted. The engine 1 is started, for example, for the purpose of notifying a passenger including a driver that the activation operation has been accepted. Note that when the engine 1 is started, sound and vibration are generated, so that the driver can easily recognize that the start operation has been accepted.

-ECU-
The ECU 100 is an electronic control device that executes the above-described hybrid system, and includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a backup RAM, and the like.

  The ROM stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU executes arithmetic processing based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores CPU calculation results and data input from each sensor, and the backup RAM is a non-volatile memory that stores data to be saved when the ignition is turned off. is there.

  As shown in FIG. 2, the ECU 100 includes an engine speed sensor 101 that detects the rotational speed (engine speed) of the crankshaft 10 that is the output shaft of the engine 1, and a wheel speed that detects the rotational speed (vehicle speed) of the wheel. Sensor 102, throttle opening sensor 103 for detecting the opening of the throttle valve of engine 1, accelerator opening sensor 104 for detecting the opening of the accelerator pedal, shift position sensor 105, P position switch 106, power switch 107, HV battery A current sensor 108 that detects a charging / discharging current of 300, a battery temperature sensor 109, a brake pedal sensor 110 that detects a pedaling force (braking force) against the brake pedal, and the like are connected. Further, the ECU 100 is connected to a sensor that indicates the operating state of the engine 1, such as a water temperature sensor that detects the engine cooling water temperature and an air flow meter that detects the intake air amount, and signals from these sensors are sent to the ECU 100. Entered.

  The ECU 100 is connected to a throttle motor 14 that opens and closes the throttle valve 13 of the engine 1, a fuel injection device (injector) 15, an ignition device 16, a brake hydraulic pressure control device 70, and the like.

  The ECU 100 executes various controls of the engine 1 including the throttle opening control (intake air amount control), the fuel injection amount control, the ignition timing control, and the like based on the output signals of the various sensors described above. To do.

  Further, the ECU 100 manages the HV battery 300 based on the integrated value of the charge / discharge current detected by the current sensor 108, the battery temperature detected by the battery temperature sensor 109, and the like. State of charge (SOC), input limit Win and output limit Wout of the HV battery 300, and the like are calculated.

  Further, the inverter 200 is connected to the ECU 100. Inverter 200 includes an IPM (Intelligent Power Module) for controlling motor generators MG1 and MG2. Each IPM is constituted by a plurality of (for example, six) semiconductor switching elements (for example, an IGBT (Insulated Gate Bipolar Transistor)).

  Inverter 200, for example, converts DC current from HV battery 300 into motor generators MG1, MG1, in accordance with command signals from ECU 100 (for example, torque command values of first motor generator MG1 and torque command values of second motor generator MG2). The HV battery 300 is charged with the alternating current generated by the first motor generator MG1 by the power of the engine 1 and the alternating current generated by the second motor generator MG2 by the regenerative brake, while converting the current to drive the MG2. To convert to direct current. Inverter 200 supplies the alternating current generated by first motor generator MG1 as drive power for second motor generator MG2 in accordance with the traveling state.

-Driving mode-
In the hybrid vehicle HV according to the present embodiment, when the engine 1 is not operating efficiently, such as when starting or running at a low speed, the vehicle travels only with the second motor generator MG2 (hereinafter also referred to as “EV travel”). I do. Further, EV traveling is also performed when the driver selects the EV traveling mode using a traveling mode selection switch disposed in the vehicle interior.

  On the other hand, during normal travel, for example, the power split mechanism 3 divides the power of the engine 1 into two paths (torque split), while the drive wheels 6L and 6R are directly driven (driven by direct torque), and the 1 Motor generator MG1 is driven to generate power. At this time, the second motor generator MG2 is driven with the generated electric power to assist driving of the driving wheels 6L and 6R (driving by an electric path). Thus, the power split mechanism 3 functions as a differential mechanism, and the main part of the power from the engine 1 is mechanically transmitted to the drive wheels 6L and 6R by the differential action, and the power from the engine 1 is transmitted. The remaining portion is electrically transmitted using an electric path from the first motor generator MG1 to the second motor generator MG2, thereby exhibiting a function as a transmission in which the gear ratio is electrically changed. As a result, the engine speed and the engine torque can be freely operated without depending on the speed and torque of the drive wheels 6L and 6R (ring gears R3 and R4), which is required for the drive wheels 6L and 6R. While obtaining the driving force, it is possible to obtain the operating state of the engine 1 in which the fuel consumption rate is optimized.

  Further, at the time of high speed traveling, the electric power from the HV battery (traveling battery) 300 is further supplied to the second motor generator MG2, and the output of the second motor generator MG2 is increased to drive the driving wheels 6L and 6R. Is added (driving force assist; power running).

  At the time of deceleration, the second motor generator MG2 functions as a generator to perform regenerative power generation, and the recovered power is stored in the HV battery 300. When the amount of charge of HV battery 300 decreases and charging is particularly necessary, the output of engine 1 is increased to increase the amount of power generated by first motor generator MG1 to increase the amount of charge for HV battery 300. Of course, there is a case where control is performed to increase the drive amount of the engine 1 as necessary even during low-speed traveling. For example, it is necessary to charge the HV battery 300 as described above, to drive auxiliary equipment such as an air conditioner, or to raise the temperature of the cooling water of the engine 1 to a predetermined temperature.

  Further, in the hybrid vehicle HV of the present embodiment, when the EV traveling condition determined based on the driving state of the hybrid vehicle HV, the state of the HV battery 300, or the like is satisfied, 1 is stopped. After that, when the EV traveling condition is not satisfied, the engine 1 is restarted. As described above, in the hybrid vehicle HV, the engine 1 is intermittently operated even when the ignition switch is in the ON position.

-Hybrid system startup processing-
Next, the starting process of the hybrid system in the hybrid vehicle HV will be described for each case when the vehicle is stopped and when the vehicle is traveling. The following processing is executed by the ECU 100.

[When stopped]
When the vehicle is stopped, the hybrid system activation process is started when the power switch 107 is operated (for example, short-pressed) while the brake pedal is depressed (recognized from the output signal of the brake pedal sensor 110). When the hybrid system is started, first, a preset system check is executed. When the system check is completed, a system main relay (not shown) is connected. The system main relay is a relay for connecting or disconnecting the HV battery 300 and the inverter 200. By connecting this system main relay, motor generators MG1 and MG2 can be driven by electric power supplied from HV battery 300, and electric power generated by motor generators MG1 and MG2 can be charged to HV battery 300. Become.

  Then, when it is cold or when the SOC of the HV battery 300 is lowered, that is, when the EV running condition is not satisfied (engine start condition is satisfied), the engine 1 is started. The engine 1 is started by the first motor generator MG1 driven by the electric power of the HV battery 300. Thereafter, a Ready-On state (a state in which the vehicle can run) is set, and an indicator lamp indicating that fact is turned on in a combination meter (not shown).

  On the other hand, when the engine 1 does not need to be warmed up and when it is not necessary to charge the HV battery 300, that is, when the EV running condition is satisfied, the engine 1 is not started and the Ready-On state is entered. Thus, an indicator lamp to that effect is lit on the combination meter.

[During driving]
In this embodiment, when a passenger (user) including a driver operates (off operation) the power switch 107 while the hybrid vehicle HV is traveling, the hybrid system is in a stop state (IG-Off state). In addition, after this (after becoming IG-Off during vehicle travel), when the power switch 107 is operated (IG-On operation), the hybrid system can be restarted. In some cases, it may be required to start the engine 1. For example, when the hybrid system is restarted, it may be required to start the engine 1 and inform the driver that the startup operation has been accepted. However, the engine 1 may not be started when the hybrid system is restarted while the vehicle is running. The reason for this will be described below.

  First, when the engine 1 is restarted by motoring by the first motor generator MG1 while the vehicle is running, the operating point of the first motor generator MG1 becomes a negative rotation region (power generation region) as shown in FIG. The first motor generator MG1 functions as a generator. When the sum of the power generated by first motor generator MG1 (power generated by the inertial power of first motor generator MG1) and the power consumed by second motor generator exceeds input limit Win of HV battery 300 When the power balance of the HV battery 300 cannot be maintained, the output torque of the first motor generator MG1 is limited, and therefore the engine 1 may not be restarted due to insufficient motoring torque. Although it is possible to reduce the excess of the input limit Win by reducing the motoring torque, in this case, there is a high possibility that the engine 1 will fail to start.

  Thus, when the engine 1 is started while the vehicle is traveling, the engine 1 may not be restarted due to the Win requirement of the HV battery 300. In particular, there is a high possibility that the engine 1 cannot be restarted when the input restriction Win of the HV battery 300 is severe at low temperatures or when the vehicle speed is high.

  In consideration of such points, in the present embodiment, after the hybrid system is stopped during traveling of the vehicle, the normal traveling engine is started when the engine 1 is started when the hybrid system is requested to restart. Compared with the time of starting, the startability of the engine 1 is improved by relaxing the restriction on the output torque of the second motor generator MG2 (the suppression torque for suppressing the torque transmitted to the drive wheels 6L and 6R).

  An example of the specific control (control when there is a restart request after stopping the hybrid system during traveling) will be described with reference to the flowchart of FIG.

  The control routine of FIG. 6 is repeatedly executed in the ECU 100 every predetermined time (for example, every several msec).

  When the control routine of FIG. 6 is started, first, in step ST101, it is determined whether or not the hybrid vehicle HV is traveling based on the vehicle speed V calculated from the output signal of the wheel speed sensor 102. If the determination result is negative (NO), the process returns. When the determination result of step ST101 is affirmative (YES) (when the vehicle is traveling), the process proceeds to step ST102.

  In step ST102, based on the output signal of the power switch 107, the hybrid system is stopped (IG-Off) by operating the power switch 107 (for example, long press: 3 seconds) while the vehicle is running (while the hybrid system is activated). If the determination result is negative (NO), the process returns. If the determination result in step ST102 is affirmative (YES) (if there is an [IG-On → IG-Off] operation while traveling), the process proceeds to step ST103.

  In addition, as an example in which a stop operation (IG-Off operation) of the hybrid system is performed during traveling, an erroneous operation of the power switch 107 by a passenger including a driver can be considered.

  In step ST103, a hybrid system stop process is executed. This stop processing of the hybrid system includes, for example, stop of the engine 1 by fuel cut, stop driving of the motor generators MG1 and MG2 by shutting off the gate of the inverter 200, shut off of the system main relay, and the like. When the hybrid system stop process is started, the indicator lamp indicating the Ready-On state is turned off.

  After the hybrid system stop process in step ST103 is completed, a running system startup control subroutine is executed in step ST104. The running system startup control subroutine will be described with reference to FIG.

  When the subroutine of FIG. 7 is started, first, in step ST141, it is determined based on the vehicle speed V calculated from the output signal of the wheel speed sensor 102 whether or not the hybrid vehicle HV is traveling. If the determination result is negative (NO), the processing of this subroutine is terminated and the process returns to the main routine. When step ST141 is affirmation determination (YES), it progresses to step ST142.

  In step ST142, based on the output signal of the power switch 107, it is determined whether a restart operation of the hybrid system (for example, a short press of the power switch 107) has been performed. If the determination result in step ST142 is negative (NO), the process returns to step ST141 and determination is performed again. In this re-determination, when the determination result of step ST141 is affirmative (YES) and the determination result of step ST142 is negative (NO), the processes of step ST141 to step ST142 are repeated.

  When the determination result in step ST142 is negative (NO), if the determination result in step ST141 is negative (NO), that is, the hybrid vehicle is not operated to restart the hybrid system. When the HV stops, the process of this subroutine is terminated and the process returns to the main routine. On the other hand, when both the determination results of step ST141 and step ST142 are affirmative (YES), that is, when the hybrid system is restarted in the accelerator-on state while the hybrid vehicle HV is traveling (hybrid system). If there is a restart request), the process proceeds to step ST143.

  In step ST143, the start-up process of the hybrid system including the start of the engine 1 is executed. The hybrid system startup processing includes, for example, system check, connection of a system main relay, startup of the engine 1, and the like. That is, when the hybrid system is restarted when the hybrid vehicle HV travels after the hybrid system is stopped, the engine 1 is started regardless of whether the EV travel condition is satisfied. When the start-up process is completed, the Ready-On state is set, and an indicator lamp indicating that fact is lit on the combination meter. When the process of step ST143 is completed, the process returns to the main routine.

  Here, the restart of the engine 1 in the above-described step ST143 is the motoring of the engine 1 by the first motor generator MG1 and the torque (reaction torque) transmitted to the drive wheels 6L and 6R along with the motoring. Is controlled by the start-up control of suppressing the output by the output torque of the second motor generator MG2 (see FIG. 4). The engine start in step ST143 is the engine start after the hybrid system is stopped. Compared with the above-described normal engine start during running, the restriction on the output torque of the second motor generator MG2 (torque suppressing the torque transmitted to the drive wheels 6L and 6R) is relaxed (the torque limit value is relaxed). The amount will be described later), the relaxed torque limit value (second upper limit value (second upper limit value> first upper limit value) ) The torque output (torque output of the second motor generator MG2) to.

  In this way, at the time of restarting the engine while traveling, the restriction of the suppression torque (reaction force canceling torque) that suppresses the output torque of the second motor generator MG2 (the torque transmitted to the drive wheels 6L and 6R) is relaxed. Suppressing exceeding the input limit Win of the HV battery 300 by consuming electric power (generated electric power of the first motor generator MG1) by the second motor generator MG2 by the amount of relaxing the torque limit (releasing the torque limit value) By performing such control, the output torque of the second motor generator MG2 slightly exceeds that during normal control when the running engine is restarted, but the torque limit of the first motor generator MG1 is exceeded. Because it can be expanded (relaxed), while maintaining the power balance (Win), the first motor Regulator MG1 becomes possible to secure a motoring torque due to, for restarting of the engine 1 is improved.

  As a result, the engine 1 may be able to be started even in a region where the engine 1 cannot be started by conventional control (a region where torque suppression transmitted to the drive wheels and power balance are not compatible). is there. Then, by improving the restartability of the engine 1 after stopping the hybrid system that is running, the driver can easily recognize that the restart operation of the hybrid system has been accepted.

  In the restart control of the engine 1 in step ST105, when the engine 1 does not start (complete explosion) when a predetermined time (for example, 2 seconds) has elapsed after the motoring of the engine 1 is started, It determines with starting of the engine 1 having failed, and returns.

[Mitigation amount of torque limit value]
Regarding the relaxation amount of the torque limit value in the case of relaxing the limitation on the output torque of the second motor generator MG2 (the suppression torque for suppressing the torque transmitted to the drive wheels 6L and 6R), the vehicle speed V of the hybrid vehicle HV Refer to and set the map based on.

  For example, the map for obtaining the amount of relaxation of the torque limit value uses the vehicle speed V as a parameter, and considers the allowable amount of increase in vehicle speed from each vehicle speed V (the allowable range of decrease in drivability due to torque limit relaxation). The amount of relaxation is obtained by experiment / calculation, etc., and a value that is adapted based on the result is mapped. In addition, since R / L (Load-Load) is large when the vehicle has a high vehicle speed, there is a large range in which the increase in the vehicle speed due to the excess of the output torque (suppression torque) of the second motor generator MG2 is allowed, Considering the fact that the absolute value of the negative rotation speed of the first motor generator MG1 increases and the amount of power generation increases as the vehicle speed increases, the output torque of the second motor generator MG2 (the higher the vehicle speed V, the higher the vehicle speed). The amount of relaxation of the limit value of (suppression torque) may be set large.

[Modification]
Next, a modified example will be described. In this modification, at the time of starting the engine while traveling, when the restriction on the output torque of the second motor generator MG2 (the suppression torque (reaction force canceling torque) that suppresses the torque transmitted to the drive wheels 6L and 6R is relaxed, In order to eliminate the point that the output torque (suppression torque) of the second motor generator MG2 exceeds (the vehicle speed increases) compared to the normal start, the hybrid vehicle HV is operated by operating the brake 7 when the engine 1 is restarted. This is characterized in that a braking force is applied to.

  Specifically, when the engine 1 is restarted in response to a restart request after the hybrid system is stopped while the vehicle is running, the torque limit value relaxation amount map is used using the vehicle speed V of the hybrid vehicle HV. From this, a relaxation amount of the torque limit value (a torque increase amount of the second motor generator MG2) is obtained, and a braking force that cancels the increased torque (drive force) is obtained. Then, the brake hydraulic pressure control device 70 of the brake device 7 is controlled so that the braking force is applied to the hybrid vehicle HV. In this way, the braking force is applied so as to cancel the output torque of the second motor generator MG2 (the driving force (the excess of the suppression torque) that increases due to the relaxation of the restriction of the suppression torque that suppresses the torque transmitted to the drive wheels 6L and 6R. Therefore, when the engine is started while the vehicle is running, the power balance and the engine startability when the engine is restarted while the suppression torque (reaction force cancellation torque) that suppresses the torque transmitted to the drive wheels is protected. It can be compatible.

  As another modified example, if there is a request to restart the hybrid system after the hybrid system is stopped while the vehicle is running, auxiliary equipment such as an air conditioner mounted on the hybrid vehicle HV is forced. A configuration in which power is consumed by driving can be given.

  By adopting such a configuration, it is possible to relax the input restriction Win of the HV battery 300 when the engine is restarted while the vehicle is running, and to increase the motoring torque by the first motor generator MG1. 1 startability is improved. In addition, you may make it perform combining the control which consumes electric power by such forced driving of auxiliary machines, and the braking force provision control for protecting the above-mentioned suppression torque.

  In the present embodiment, when the hybrid system is requested to restart after the hybrid system is stopped during traveling of the vehicle, the suppression torque (reaction force canceling torque) by the second motor generator MG2 is ensured. If this is not possible, the engine 1 may be stopped from starting.

-Other embodiments-
In the above example, the power switch 107, which is a rebound push switch, is used as the operation unit for operating the hybrid system to start and stop, but the present invention is not limited to this. For example, a lever switch, a slide switch, or a key switch that rotates by inserting a key into a cylinder may be used as long as the operation unit can accept an operation.

  In the above example, the example in which the present invention is applied to the control of the hybrid vehicle of the FF (front engine / front drive) type is shown, but the present invention is not limited to this, and the FR (front engine / rear drive) type is used. The present invention can also be applied to the control of a hybrid vehicle of this type or a four-wheel drive hybrid vehicle.

  In the above example, the example in which the present invention is applied to the control of the hybrid vehicle on which the two rotating electric machines of the first motor generator MG1 and the second motor generator MG2 are mounted has been described. It is also possible to apply to a hybrid vehicle in which at least one of them assists the driving force of the vehicle.

  The present invention is applicable to a control device for a hybrid vehicle equipped with an engine and a motor generator. More specifically, the engine is motored by the first motor generator when the engine is started while the vehicle is running. The present invention can be applied to a hybrid vehicle control device capable of executing control for limiting the torque transmitted to the drive wheels along with the motoring by the first motor generator by the output torque of the second motor generator.

1 Engine 10 Crankshaft (engine output shaft)
3 Power split mechanism (differential mechanism)
S3 Sun gear R3 Ring gear P3 Pinion gear CA3 Planetary carrier 6L, R Drive wheel (front wheel)
7 Brake device 70 Brake hydraulic control device 100 ECU
200 inverter 300 HV battery MG1 first motor generator MG2 second motor generator

Claims (6)

An engine that outputs a driving force for driving the vehicle; a first motor generator and a second motor generator that can input and output power to a power transmission path from an output shaft of the engine to a driving wheel of the vehicle; and A power storage device capable of inputting and outputting electric power between the motor generator and the second motor generator;
When the engine is started, the engine is motored by the first motor generator, and the torque transmitted to the drive wheels along with the motoring by the first motor generator is output torque of the second motor generator. In a hybrid vehicle control device capable of performing control to be suppressed at
When the engine is started when there is a request to restart the vehicle system before the vehicle stops after the vehicle system is stopped while the vehicle is running, A control apparatus for a hybrid vehicle, wherein the restriction on the output torque of the two-motor generator is relaxed. In the hybrid vehicle control device according to claim 1,
Braking force applying means for applying a mechanical braking force to the vehicle, and when the engine is started when the vehicle system is requested to restart while the vehicle is running, A control device for a hybrid vehicle, characterized in that a braking force is applied to the vehicle so as to cancel out a driving force that increases due to relaxation of the restriction on the output torque of the second motor generator. In the hybrid vehicle control device according to claim 1 or 2,
When a restart of the vehicle system is requested after the vehicle system is stopped while the vehicle is running, when the engine is started, the auxiliary equipment mounted on the vehicle is forcibly driven to generate power. A control device for a hybrid vehicle, characterized by consuming the power. In the control apparatus of the hybrid vehicle as described in any one of Claims 1-3,
Ensuring the output torque of the second motor generator for suppressing the torque transmitted to the drive wheels when a restart request of the vehicle system is made after the vehicle system is stopped while the vehicle is running A hybrid vehicle control device that stops starting the engine when it cannot. In the control apparatus of the hybrid vehicle as described in any one of Claims 1-4,
An operation unit that receives operations for starting and stopping the vehicle system;
After the rider performs an operation of stopping the vehicle system using the operation unit while the vehicle is running, the rider uses the operation unit to stop the vehicle system before the vehicle stops. A control apparatus for a hybrid vehicle configured to execute control at the time of starting the engine when an operation for starting the engine is performed. In the control apparatus of the hybrid vehicle as described in any one of Claims 1-4,
An operation unit that receives operations for starting and stopping the vehicle system;
When a signal for starting the vehicle system is received from the operation unit after the signal for stopping the vehicle system is received from the operation unit while the vehicle is running, before the vehicle is stopped, A control apparatus for a hybrid vehicle configured to execute control at the time of starting an engine.

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