JP5510165B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a technical field of a control device for a hybrid vehicle that controls a hybrid vehicle configured to realize various power transmission modes by controlling operations of a plurality of rotating elements.

  In this type of hybrid vehicle, all the power output from the engine is converted to drive power of the electric motor and output to the drive shaft, and the power output from the engine is output to the drive shaft as mechanical power. At the same time, the parallel mode in which the remainder is converted into electric power and output to the drive shaft is automatically switched in accordance with the driving situation or the like.

The power transmission mode switching operation described above can be realized by providing a planetary gear configured as a power transmission mechanism with a clutch that can be disconnected and coupled. For example, Patent Document 1 describes a hybrid vehicle including a first clutch that controls transmission of power to a drive shaft and a second clutch that integrally rotates a planetary gear. The clutch is, for example, a rotatable dog clutch. And the number of rotations of the engaging portion is synchronized during the engagement. In such synchronous control, engine torque and rotation speed are controlled. For example, Patent Document 2 proposes a technique of synchronizing the rotational speed after increasing the engine torque when switching from the series mode to the parallel mode. Patent Document 3 proposes a technique in which the engine is engaged with the transmission input shaft after controlling the rotation speed of the transmission input shaft to be equal to or higher than the engine rotation speed.

JP 2000-209706 A JP 2000-299903 A JP 2005-313757 A

  However, in the technique described in Patent Document 3 described above, when engaging the clutch, it is required to first increase the rotational speed of the transmission input shaft, and therefore the timing of engagement is delayed. There is a fear. For this reason, if it takes time to set the rotation speed of the transmission input shaft to be equal to or higher than the engine rotation speed, switching of the power transmission mode is delayed by that much. If the switching of the power transmission mode is delayed, for example, it becomes difficult to realize optimum fuel consumption, and drivability may be significantly deteriorated.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide a control device for a hybrid vehicle that can suitably perform switching of a power transmission mode using a clutch.

  In order to solve the above problems, a control device for a hybrid vehicle according to the present invention includes a power element including a first motor, a second motor, and an internal combustion engine, a drive shaft that transmits power from the power element to an axle, 1st rotation element connected to 1 electric motor, 2nd rotation element connected to said 2nd electric motor and said drive shaft, respectively, and 3rd rotation element connected to said internal combustion engine are mutually differentially rotatable A power transmission mechanism having a plurality of rotating elements; a first clutch capable of disconnecting and coupling the second rotating element with the second electric motor and the drive shaft; the first rotating element; and the second rotating element. And a device for controlling a hybrid vehicle including a second clutch capable of separating and coupling two of the third rotating elements to each other, wherein the first clutch and the second clutch The switching means for switching the power transmission mode by controlling the combined state, and the switching means, when the first clutch is switched from the disconnected state to the connected state, the first clutch is disconnected. A first control means for controlling the switching means so that the second clutch is engaged, and a rotational speed estimation for estimating the rotational speed of the internal combustion engine after the first clutch is engaged with the first clutch disconnected. And the switching means to engage the first clutch when the internal combustion engine is not activated when the rotational speed of the internal combustion engine estimated by the rotational speed estimation means is less than a predetermined threshold value. And second control means for controlling.

  The hybrid vehicle according to the present invention includes, as power elements capable of supplying power to the drive shaft, for example, first and second electric motors that can be configured as motor generators such as motor generators, respectively, fuel types, fuel supply modes, The vehicle includes at least an internal combustion engine that can adopt various modes regardless of the fuel combustion mode, the configuration of the intake / exhaust system, the cylinder arrangement, and the like. The hybrid vehicle control device according to the present invention is a control device that controls such a hybrid vehicle, and includes, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors, or various controllers. Alternatively, various processing units such as a single or plural ECUs (Electronic Controlled Units), which may appropriately include various storage means such as ROM (Read Only Memory), RAM (Random Access Memory), buffer memory or flash memory Various computer systems such as various controllers or microcomputer devices can be used.

  The hybrid vehicle according to the present invention includes a power transmission mechanism that transmits power between the power elements and the drive shaft described above. The power transmission mechanism includes a plurality of rotating elements including a first rotating element connected to the first electric motor, a second rotating element connected to the second electric motor and the drive shaft, respectively, and a third rotating element connected to the internal combustion engine. The state of each rotating element (in short, it is a physical state that defines the mode of rotation, whether it is rotatable and whether it is connected to other rotating elements, etc. Power transmission is performed according to various power transmission modes determined according to The power transmission mechanism can take a gear mechanism such as one or a plurality of planetary gear mechanisms as a preferred form. When a plurality of planetary gear mechanisms are included, a plurality of rotating elements constituting each planetary gear mechanism are included. These planetary gear mechanisms can be shared as appropriate.

  The hybrid vehicle according to the present invention further includes a first clutch, a first rotating element, a second rotating element, and a second rotating element that can be disconnected and connected to the second electric motor and the drive shaft of the second rotating element in the power transmission mechanism. A second clutch capable of separating and coupling two of the three rotating elements to each other is provided. The first clutch realizes power transmission to the second electric motor and the drive shaft by engaging two engaging portions that can be rotated with each other, and transmits power to the second electric motor and the drive shaft by being disconnected. Can be cut off. The second clutch couples two rotating elements with each other by two engaging portions that are made rotatable, and integrally rotates a power transmission mechanism configured as, for example, a planetary gear mechanism. The second clutch is typically configured to connect the second rotating element and the third rotating element.

  The control apparatus for a hybrid vehicle according to the present invention includes switching means for controlling the first clutch and the second clutch described above to change the state of the power transmission mechanism and to switch the power transmission mode. The switching means can realize at least four power transmission modes by controlling the coupling state of the first clutch and the second clutch. Specifically, a power transmission mode in which both the first clutch and the second clutch are disengaged (hereinafter referred to as “first mode” where appropriate), the first clutch is disengaged, and the second clutch is disengaged. A power transmission mode in which the first clutch and the second clutch are coupled together (hereinafter referred to as “third mode” as appropriate) and a power transmission mode in which the first clutch and the second clutch are coupled together (hereinafter referred to as “second mode” where appropriate). And a power transmission mode in which the first clutch is engaged and the second clutch is disengaged (hereinafter referred to as “fourth mode” as appropriate).

  In the first mode, since the first clutch is disengaged, no power is output from the power transmission mechanism to the drive shaft. For this reason, the hybrid vehicle travels with the power output from the second electric motor located on the downstream side of the power transmission mechanism. That is, the first mode can be referred to as a mode in which only power is used without using power from the internal combustion engine. Particularly in the first mode, since the second clutch is also disengaged, energy loss due to dragging or the like in the power transmission mechanism can be prevented. Therefore, extremely high energy efficiency can be realized.

  In the second mode, since the first clutch is disengaged as in the first mode described above, no power is output from the power transmission mechanism to the drive shaft. For this reason, the hybrid vehicle travels with the power output from the second electric motor located on the downstream side of the power transmission mechanism. However, in the second mode, since the second clutch is in a coupled state, the power transmission mechanism rotates integrally. For this reason, the motive power of the internal combustion engine can be transmitted to the first electric motor for regeneration. Since the electric power regenerated in the first electric motor can be used as power for the second electric motor, it is possible to extend the travel distance of the vehicle as compared with the first mode.

  In the third mode, since the first clutch is engaged, power is output from the power transmission mechanism to the drive shaft. For this reason, the hybrid vehicle travels with power from the internal combustion engine. Since the second clutch is connected and the power split mechanism can rotate integrally, a part of the power from the internal combustion engine can be used for regeneration by the first electric motor. Further, driving that assists the power from the internal combustion engine by outputting power from the second electric motor is also possible. In the third mode, it is possible to improve the efficiency during high-speed and low-load traveling where it is difficult to obtain the efficiency improvement effect in the second mode described above. Furthermore, emergency evacuation traveling (that is, traveling only with the internal combustion engine) is possible when a failure occurs in the first electric motor and the second electric motor.

  In the fourth mode, since the first clutch is engaged as in the third mode described above, power is output from the power transmission mechanism to the drive shaft. For this reason, the hybrid vehicle travels with power from the internal combustion engine. Here, particularly in the fourth mode, when the power output from the internal combustion engine is larger than the target power, the remainder of the power is transmitted to the first motor and regenerated. On the other hand, when the power output from the internal combustion engine is smaller than the target power, the power output from the internal combustion engine and the power output from the first motor are output to the drive shaft, and the remaining power is Regenerated in the second electric motor. According to the fourth mode, high efficiency can be realized regardless of the vehicle speed.

  As described above, according to the control apparatus for a hybrid vehicle of the present invention, highly efficient driving can be realized by appropriately switching the power transmission mode according to the traveling state of the vehicle. Note that the switching operation of the power transmission mode by the switching means is automatically performed based on a mode switching instruction that is output according to the traveling state of the vehicle.

  Here, in the present invention, particularly when the first clutch is switched from the disconnected state to the connected state by the switching means, the first control means first connects the second clutch with the first clutch disconnected. The switching means is controlled so that That is, when the first clutch is engaged, the engagement of the second clutch is executed first. When the first clutch is to be engaged and the second clutch is already engaged, the first control means need not control the switching means.

  When the second clutch is engaged, the rotational speed estimating means estimates the rotational speed of the internal combustion engine after the first clutch is engaged. The estimation of the rotational speed is performed with the first clutch disconnected. That is, the rotational speed of the internal combustion engine that will be realized when the first clutch is engaged is estimated. The rotational speed of the internal combustion engine can be estimated using, for example, the vehicle speed.

  It is determined whether or not the rotational speed of the internal combustion engine estimated by the rotational speed estimation means is less than a predetermined threshold value. Here, the “predetermined threshold value” is a value for determining whether the rotational speed is low enough to cause a malfunction in the internal combustion engine when the first clutch is engaged. Specifically, the engine idle speed and start speed are set. When the estimated rotational speed of the internal combustion engine is less than a predetermined threshold value, the second control means controls the switching means so that the first clutch is engaged when the internal combustion engine is not activated. That is, the first clutch is engaged before starting the internal combustion engine that has been stopped. Alternatively, the first clutch is engaged after the started internal combustion engine is stopped. Here, the “not activated” state refers to a state in which no power is output from the internal combustion engine, and even if the internal combustion engine is rotating, it is output from other power elements. If the rotation is caused by the motive power, it is included in the “not activated state”.

  Here, it is assumed that the first clutch is engaged in a state where the internal combustion engine is started when the rotational speed of the internal combustion engine is less than a predetermined threshold value. In this case, the internal combustion engine is coupled to the drive shaft in a state where it cannot rotate independently. For this reason, in an internal combustion engine, misfires, resonances, and the like are likely to occur, and drivability is expected to be deteriorated due to the occurrence.

  However, in the present invention, as described above, since the first clutch is engaged in a state where the engine is not started, various problems occurring in the above-described internal combustion engine can be prevented. Further, when the first clutch is coupled, synchronous control for synchronizing the rotation of the engaging portion is performed. However, since the second clutch is coupled in the present invention, the accuracy is relatively high. Synchronous control using a high first motor can be executed. Therefore, it is possible to improve controllability and merchantability, such as shortening the coupling time and reducing the shock during coupling.

  As described above, according to the hybrid vehicle control device of the present invention, it is possible to suitably switch the power transmission mode using the clutch.

  In one aspect of the control apparatus for a hybrid vehicle of the present invention, when the first clutch is engaged when the internal combustion engine is not activated, the rotational speed of the internal combustion engine after the first clutch is engaged is detected. The apparatus further comprises a rotation speed detection means and a start control means for starting the internal combustion engine when the rotation speed of the internal combustion engine detected by the rotation speed detection means is equal to or greater than a predetermined threshold value.

  According to this aspect, after the first clutch is engaged while the internal combustion engine is not activated, the rotational speed of the internal combustion engine is detected by the rotational speed detection means. That is, instead of estimating the rotational speed without coupling the first clutch as in the rotational speed estimation means, the rotational speed in the state where the first clutch is actually coupled is detected. The rotation speed of the internal combustion engine is detected at a constant or indefinite period after the first clutch is engaged.

  In this aspect, when the detected rotational speed of the internal combustion engine becomes equal to or greater than a predetermined threshold value, the stopped internal combustion engine is started by the start control means. If the rotational speed of the internal combustion engine after engagement of the first clutch is equal to or greater than a predetermined threshold, it is considered that no malfunction will occur even if the internal combustion engine is started. Therefore, it is possible to suitably realize traveling using the power output from the internal combustion engine.

  In another aspect of the hybrid vehicle control apparatus of the present invention, the internal combustion engine is started and the first electric motor is activated when the rotational speed of the internal combustion engine estimated by the rotational speed estimation means is greater than or equal to a predetermined threshold value. And further comprising third control means for controlling the switching means so as to engage the first clutch while performing regeneration.

  According to this aspect, when the rotational speed of the internal combustion engine estimated by the rotational speed estimation means is greater than or equal to the predetermined threshold value (that is, the first clutch is not engaged without starting the internal combustion engine described above). In the case), the internal combustion engine is started and regeneration by the first electric motor is performed using the power of the internal combustion engine. That is, the power output from the internal combustion engine is transmitted through the power transmission mechanism, and power is generated in the first motor.

  In this aspect, the synchronization of the first clutch is performed in the state described above, and the coupling is executed. That is, the coupling control of the first clutch is executed in a state where the internal combustion engine outputs power and the first electric motor takes the reaction force. In this case, since the internal combustion engine is in the activated state, it is possible to create a state in which the torque and the rotational speed are relatively stable. Therefore, the controllability in the synchronous control of the first clutch can be improved. In addition, since regeneration is performed in the first electric motor, it is possible to prevent the first clutch coupling control from being stopped due to power shortage. Furthermore, since power generation by the second electric motor is not necessary, energy efficiency can be improved.

  The effect | action and other gain of this invention are clarified from the form for implementing invention demonstrated below.

1 is a schematic configuration diagram conceptually showing a configuration of a hybrid vehicle. 1 is a schematic configuration diagram conceptually showing a configuration of a hybrid drive device. 2 is a schematic view illustrating a cross-sectional configuration of an engine 200. FIG. It is a block diagram which shows the structure of ECU. It is a matrix figure which shows four power transmission modes implement | achieved by the control apparatus of a hybrid vehicle. It is an alignment chart which shows the structure of a 1st mode. It is an alignment chart which shows the structure of 2nd mode. It is an alignment chart which shows the structure of 3rd mode. It is an alignment chart which shows the structure of 4th mode. It is a flowchart which shows operation | movement of the control apparatus of a hybrid vehicle. FIG. 6 is a collinear diagram (part 1) illustrating synchronization control when the first clutch is engaged. FIG. 10 is a collinear diagram (part 2) illustrating synchronization control when the first clutch is engaged.

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

  First, the overall configuration of the hybrid vehicle according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle.

  In FIG. 1, a hybrid vehicle 1 according to the present embodiment includes a hybrid drive device 10, a PCU (Power Control Unit) 11, a battery 12, an accelerator opening sensor 13, a vehicle speed sensor 14, and an ECU 100.

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1, and is an example of the “hybrid vehicle control device” according to the present invention. The ECU 100 is configured to be able to execute various controls in the hybrid vehicle 1 according to a control program stored in a ROM or the like, for example.

  The PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to a motor generator MG1 and a motor generator MG2 described later. Further, an inverter (not shown) that can convert AC power generated by motor generator MG1 and motor generator MG2 into DC power and supply it to battery 12 is included. That is, the PCU 11 inputs / outputs power between the battery 12 and each motor generator, or inputs / outputs power between the motor generators (that is, in this case, the power between the motor generators without passing through the battery 12). The power control unit is configured to be controllable. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 is a rechargeable power storage unit that functions as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening Ta as an operation amount of an accelerator pedal (not shown) of the hybrid vehicle 1. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Ta is referred to by the ECU 100 at a constant or indefinite period.

  The vehicle speed sensor 14 is a sensor configured to be able to detect the vehicle speed V of the hybrid vehicle 1. The vehicle speed sensor 14 is electrically connected to the ECU 100, and the detected vehicle speed V is referred to by the ECU 100 at a constant or indefinite period.

  The hybrid drive device 10 is a power unit that functions as a power train of the hybrid vehicle 1. Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 2, the hybrid drive apparatus 10 mainly includes an engine 200, a power split mechanism 300, a motor generator MG1 (hereinafter appropriately referred to as “MG1”), a motor generator MG2 (hereinafter appropriately referred to as “MG2”), An input shaft 400, a drive shaft 500, a speed reduction mechanism 600, a first clutch 710, and a second clutch 720 are provided.

  The engine 200 is a gasoline engine which is an example of the “internal combustion engine” according to the present invention, and is configured to function as a main power source of the hybrid vehicle 1. Here, the detailed configuration of the engine 200 will be described with reference to FIG. FIG. 3 is a schematic view illustrating a cross-sectional configuration of the engine 200. The “internal combustion engine” in the present invention includes, for example, a 2-cycle or 4-cycle reciprocating engine, and has at least one cylinder, and various fuels such as gasoline, light oil, alcohol, etc. in the combustion chamber inside the cylinder. Includes an engine configured to be able to take out the force generated when the air-fuel mixture containing gas is burned as a driving force through appropriate physical or mechanical transmission means such as pistons, connecting rods and crankshafts. It is a concept to do. As long as the concept is satisfied, the configuration of the internal combustion engine according to the present invention is not limited to that of the engine 200 and may have various aspects. Further, the engine 200 is an in-line four-cylinder engine in which four cylinders 201 are arranged in series in a direction perpendicular to the paper surface, but the configuration of each cylinder 201 is equal to each other. Only the cylinder 201 will be described.

  In FIG. 3, the engine 200 burns the air-fuel mixture through an ignition operation by an ignition device 202 in which a part of a spark plug (not shown) is exposed in a combustion chamber in a cylinder 201, and the explosive force due to such combustion. The reciprocating motion of the piston 203 that occurs in response to the above is converted into the rotational motion of the crankshaft 205 via the connecting rod 204.

  In the vicinity of the crankshaft 205, a crank position sensor 206 for detecting the rotational position (ie, crank angle) of the crankshaft 205 is installed. The crank position sensor 206 is electrically connected to the ECU 100 (not shown), and the ECU 100 calculates the engine speed NE of the engine 200 based on the crank angle signal output from the crank position sensor 206. It is the composition which becomes.

  In the engine 200, air sucked from the outside passes through the intake pipe 207 and is guided into the cylinder 201 through the intake port 210 when the intake valve 211 is opened. On the other hand, the fuel injection valve of the injector 212 is exposed at the intake port 210, so that fuel can be injected into the intake port 210. The fuel injected from the injector 212 is mixed with the intake air before and after the opening timing of the intake valve 211 to become the above-described mixture.

  The fuel is stored in a fuel tank (not shown), and is supplied to the injector 212 via a delivery pipe (not shown) by the action of a feed pump (not shown). The air-fuel mixture combusted inside the cylinder 201 becomes exhaust, and is led to the exhaust pipe 215 via the exhaust port 214 when the exhaust valve 213 that opens and closes in conjunction with the opening and closing of the intake valve 211 is opened.

  On the other hand, on the upstream side of the intake port 210 in the intake pipe 207, a throttle valve 208 capable of adjusting the intake air amount related to the intake air guided through a cleaner (not shown) is disposed. The throttle valve 208 is configured such that its drive state is controlled by a throttle valve motor 209 electrically connected to the ECU 100. The ECU 100 basically controls the throttle valve motor 209 so as to obtain a throttle opening corresponding to the opening of an accelerator pedal (not shown) (that is, the accelerator opening Ta described above). It is also possible to adjust the throttle opening without intervention of the driver's intention through the operation control of 209. That is, the throttle valve 208 is configured as a kind of electronically controlled throttle valve.

  A three-way catalyst 216 is installed in the exhaust pipe 215. The three-way catalyst 216 is configured to reduce NOx (nitrogen oxides) in the exhaust discharged from the engine 200 and at the same time to oxidize CO (carbon monoxide) and HC (hydrocarbon) in the exhaust. It is. In addition, the form which a catalyst apparatus can take is not limited to such a three-way catalyst, For example, instead of or in addition to the three-way catalyst, various catalysts such as an NSR catalyst (NOx storage reduction catalyst) or an oxidation catalyst are installed. May be.

  An air-fuel ratio sensor 217 configured to be able to detect the exhaust air-fuel ratio of the engine 200 is installed in the exhaust pipe 215. Further, a water temperature sensor 218 for detecting the cooling water temperature related to the cooling water (LLC) circulated and supplied to cool the engine 200 is disposed in the water jacket installed in the cylinder block that houses the cylinder 201. ing. The air-fuel ratio sensor 217 and the water temperature sensor 218 are electrically connected to the ECU 100, and the detected air-fuel ratio and cooling water temperature are grasped by the ECU 100 at a constant or indefinite detection cycle. .

  Returning to FIG. 2, motor generator MG <b> 1 is a motor generator that is an example of a “first motor” according to the present invention, and includes a power running function that converts electrical energy into kinetic energy, and a regeneration function that converts kinetic energy into electrical energy. It is the composition provided with. The motor generator MG2 is a motor generator that is an example of a “second motor” according to the present invention. Like the motor generator MG1, the motor generator MG2 converts a power running function that converts electrical energy into kinetic energy, and converts kinetic energy into electrical energy. It has a configuration with a regenerative function. Motor generators MG1 and MG2 are configured as, for example, synchronous motor generators, and include, for example, a rotor having a plurality of permanent magnets on an outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. However, it may have other configurations.

  The power split mechanism 300 includes a sun gear S1 as an example of the “first rotating element” according to the present invention provided in the center, and a “second rotation” according to the present invention provided concentrically on the outer periphery of the sun gear S1. The present invention includes a ring gear R1 as an example of an element, a plurality of pinion gears P1 disposed between the sun gear S1 and the ring gear R1, and revolving while rotating on the outer periphery of the sun gear S1, and the rotation shafts of these pinion gears. And a carrier C1 as an example of the “third rotating element”. That is, the power split mechanism 300 is a power transmission device as an example of the “power transmission mechanism” according to the present invention.

  Here, the sun gear S1 is connected to the rotor RT1 of the MG1 via the sun gear shaft 310, and the rotation speed is equivalent to the rotation speed Nmg1 of the MG1 (hereinafter referred to as “MG1 rotation speed Nmg1” as appropriate). The ring gear R1 is coupled to the rotor RT2 of the MG2 via the drive shaft 500 and the speed reduction mechanism 600, and the rotation speed is uniquely defined as the rotation speed Nmg2 of the MG2 (hereinafter referred to as “MG2 rotation speed Nmg2” as appropriate). Is in a similar relationship. Further, the carrier C1 is connected to the input shaft 400 connected to the crankshaft 205 described above of the engine 200, and the rotational speed thereof is equivalent to the engine rotational speed NE of the engine 200. In the hybrid drive device 10, the MG1 rotation speed Nmg1 and the MG2 rotation speed Nmg2 are detected by a rotation sensor such as a resolver at a constant cycle, and are sent to the ECU 100 at a constant or indefinite cycle.

  On the other hand, the drive shaft 500 is a drive shaft SFR and SFL that respectively drive the right front wheel FR and the left front wheel FL that are drive wheels of the hybrid vehicle 1 (that is, these drive shafts are examples of the “axle” according to the present invention). And a reduction mechanism 600 as a reduction device including various reduction gears and differential gears. Therefore, the motor torque Tmg2 supplied from the motor generator MG2 to the drive shaft 500 is transmitted to each drive shaft via the speed reduction mechanism 600, and the drive force transmitted from each drive wheel via each drive shaft is Similarly, it is input to motor generator MG2 via reduction mechanism 600 and drive shaft 500. Therefore, the MG2 rotational speed Nmg2 is uniquely related to the vehicle speed V of the hybrid vehicle 1.

  Under such a configuration, the power split mechanism 300 supplies the engine torque Te supplied from the engine 200 to the input shaft 400 via the crankshaft 205 to the sun gear S1 and the ring gear R1 by a predetermined ratio (by the carrier C1 and the pinion gear P1). The power of the engine 200 can be divided into two systems.

  In order to make the operation of the power split mechanism 300 easy to understand, when the gear ratio ρ as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, when the engine torque Te is applied to the carrier C1 from the engine 200, the sun gear The torque Tes appearing on the shaft 310 is expressed by the following equation (1), and the torque Ter appearing on the drive shaft 500 (that is, the direct torque from the engine 200) is expressed by the following equation (2).

Tes = −Te × ρ / (1 + ρ) (1)
Ter = Te × 1 / (1 + ρ) (2)
The power split mechanism 300 according to the present embodiment further includes a first clutch 710 between the ring gear R1 and the drive shaft 500, and the coupling between the ring gear R1 and the drive shaft 500 and MG2 is disconnected and coupled depending on the engaged state. Is possible. Specifically, when the first clutch 710 is disengaged, the power output from the engine 200 or MG1 via the ring gear R1 is not transmitted to the drive shaft 500 and MG2. On the other hand, when the first clutch 710 is engaged, the power output via the ring gear R1 is transmitted to the drive shaft 500 and MG2.

  The power split mechanism 300 includes a second clutch 720 that can disconnect and connect the ring gear R1 and the carrier C1. When the second clutch 720 is engaged, the ring gear R1 and the carrier C1 are connected to each other, so that the power split mechanism 300 is integrally rotated. That is, the second clutch 720 is a mechanism for determining whether or not the power split mechanism 300 is allowed to rotate integrally.

  The first clutch 710 and the second clutch 720 described above are configured as, for example, rotatable meshing dog clutches, and can be independently controlled. In this way, a plurality of types of power transmission modes can be realized by controlling the engagement states of the first clutch 710 and the second clutch 720, respectively. A specific configuration of the power transmission mode will be described in detail later.

  Next, a specific configuration of the ECU 100 that is the control device for the hybrid vehicle according to the present embodiment will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the ECU.

  4, the ECU 100 includes a mode change instruction unit 110, a first control unit 120, a rotation speed estimation unit 130, a second control unit 140, a third control unit 150, a mode switching control unit 160, a rotation speed detection unit 170, and an activation. A control unit 180 is provided.

  The mode change instruction unit 110 determines whether or not the power transmission mode should be changed based on various input parameters (for example, parameters indicating the driving situation of the hybrid vehicle 1). The determination conditions here are stored in advance in a storage device such as a ROM, for example, and the hybrid vehicle 1 is controlled to be in an optimum power transmission mode according to the driving situation. If the mode change instruction unit 110 determines that the power transmission mode should be changed, the mode change instruction unit 110 outputs a mode change command so as to change the power transmission mode.

  The first control unit 120 is an example of the “first control unit” of the present invention, and engages the second clutch 720 when an instruction to engage the first clutch 710 is issued from the mode change instruction unit 110. The mode switching control unit 160 is controlled as described above.

  The rotation speed estimation unit 130 is an example of the “rotation speed estimation unit” in the present invention, and includes, for example, an arithmetic circuit and a memory. The rotation speed estimation unit 130 estimates the rotation speed of the engine 200 when the first clutch 710 is engaged without engaging the first clutch 710. The rotational speed of the engine 200 can be estimated using, for example, the vehicle speed.

  The second control unit 140 is an example of the “second control unit” of the present invention, and the mode switching control unit 160 is used when the rotational speed of the engine 200 estimated by the rotational speed estimation unit 130 is less than a predetermined threshold. To engage the first clutch. Specifically, the engagement control of the first clutch 710 is performed in a state where the engine 200 is not started.

  The third control unit 150 is an example of the “third control unit” in the present invention, and the mode switching control unit 160 is used when the rotational speed of the engine 200 estimated by the rotational speed estimation unit 130 is equal to or greater than a predetermined threshold. To engage the first clutch. A specific control method by the third control unit 150 will be described in detail later.

  The mode switching control unit 160 is an example of the “switching unit” of the present invention, and the first clutch 710 of the power split mechanism 300 is in accordance with instructions from the first control unit 120, the second control unit 140, and the third control unit 150. And the engagement state of the 2nd clutch 720 is controlled.

  The rotational speed detection unit 170 is an example of the “rotational speed detection means” in the present invention, and detects the rotational speed of the engine 200 after the first clutch 710 is engaged. The rotational speed detection unit 170 may be configured as a rotational speed sensor that directly detects the rotational speed of the engine 200, or indirectly detects the rotational speed of the engine 200 using, for example, the rotational speed of MG1 or the like. It may be configured as a thing.

  The activation control unit 180 is an example of the “activation control unit” in the present invention, and activates the engine 200 when the rotation speed detected by the rotation speed detection unit 170 is equal to or greater than a predetermined threshold value.

  The ECU 100 is an integrated electronic control unit configured to include the above-described units, and all operations related to the above-described units are configured to be executed by the ECU 100. However, the physical, mechanical, and electrical configurations of the above-described means according to the present invention are not limited thereto. For example, each of these means includes various ECUs, various processing units, various controllers, microcomputer devices, and the like. It may be configured as a computer system or the like.

  Next, the power transmission mode in the hybrid vehicle according to the present embodiment will be described with reference to FIGS. FIG. 5 is a matrix diagram showing four power transmission modes realized by the hybrid vehicle control device. 6 is a collinear diagram showing the configuration of the first mode, FIG. 7 is a collinear diagram showing the configuration of the second mode, FIG. 8 is a collinear diagram showing the configuration of the third mode, and FIG. It is an alignment chart which shows the structure of 4th mode.

  5 and 6, in the first mode, the first clutch 710 is disengaged (that is, is OFF), so that no power is output from the ring gear R1 in the power split mechanism 300 to the drive shaft 500. . For this reason, the hybrid vehicle 1 travels with the power output from the MG 2 located on the downstream side of the power split mechanism 300. That is, the first mode can be called a mode in which the power from the engine 200 is not used and the vehicle runs only with electric power. Particularly in the first mode, since the second clutch 720 is also disconnected (that is, is OFF), energy loss due to dragging or the like in the power split mechanism 300 can be prevented. Therefore, extremely high energy efficiency can be realized.

  5 and 7, in the second mode, the first clutch 710 is disengaged in the same manner as in the first mode described above, and therefore power is output from the ring gear R1 in the power split mechanism 300 to the drive shaft 500. Not. For this reason, the hybrid vehicle 1 travels with the power output from the MG 2 located on the downstream side of the power split mechanism 300. However, in the second mode, since the second clutch 720 is engaged (that is, ON), the power split mechanism 300 rotates integrally. For this reason, the power of the engine 200 can be transmitted to the MG 1 and regenerated. The electric power regenerated in MG1 can be used as power for MG2. For this reason, in the second mode, it is possible to extend the travel distance of the vehicle compared to the first mode.

  5 and 8, in the third mode, since the first clutch 710 is coupled, power is output to the drive shaft 500 from the ring gear R <b> 1 in the power split mechanism 300. For this reason, the hybrid vehicle 1 travels with the power from the engine 200. Since second clutch 720 is coupled and power split mechanism 300 can rotate integrally, a part of the power from engine 200 can be used for regeneration by MG1. Further, driving that assists the power from the engine 200 by outputting power from the MG 2 is also possible. In the third mode, it is possible to improve the efficiency during high-speed and low-load traveling where it is difficult to obtain the efficiency improvement effect in the second mode described above. Furthermore, emergency evacuation traveling (that is, traveling with only the engine 200) is possible when a malfunction occurs in MG1 and MG2.

  5 and 9, in the fourth mode, since the first clutch 710 is coupled as in the third mode described above, power is output to the drive shaft 500 from the ring gear R1 in the power split mechanism 300. Is done. For this reason, the hybrid vehicle 1 travels with the power from the engine 200. Here, especially in the fourth mode, when the power output from the engine 200 is larger than the target power, the remainder of the power is transmitted to the MG 1 and regenerated. On the other hand, when the power output from engine 200 is smaller than the target power, the power output from engine 200 and the power output from MG1 are output to drive shaft 500, and the remaining power is MG2. It is regenerated in. According to the fourth mode, high efficiency can be realized regardless of the vehicle speed.

  As described above, according to the control apparatus for a hybrid vehicle of the present invention, highly efficient driving can be realized by appropriately switching the power transmission mode according to the traveling state of the vehicle.

  Next, specific control and its effects by the hybrid vehicle control device according to the present embodiment will be described with reference to FIG. FIG. 10 is a flowchart showing the operation of the control device for the hybrid vehicle.

  10, in the hybrid vehicle control device according to the present embodiment, when a request is issued from the mode change instruction unit 110 to engage the first clutch 710 (step S01: YES), the second control unit 120 Then, the second clutch 720 is engaged without engaging the first clutch 710 (step S02). That is, when the first clutch 710 is to be coupled, the second clutch 720 is first coupled first. If the second clutch 720 is already engaged, the process of step S02 can be omitted.

  When the second clutch 720 is engaged, the rotational speed estimation unit 130 estimates the rotational speed of the engine 200 after the first clutch 710 is engaged (step S03). The estimation of the rotation speed of the engine 200 here is performed with the first clutch 710 disconnected. That is, the rotational speed of the engine 200 is estimated by calculation using parameters such as the vehicle speed without actually engaging the first clutch 710.

  When the rotational speed of engine 200 is estimated, it is determined whether the rotational speed is equal to or greater than a predetermined threshold (step S04). As the predetermined threshold value, for example, an engine idling speed and a starting speed are set.

  Here, when the estimated number of revolutions of engine 200 is equal to or greater than a predetermined threshold (step S04: YES), synchronous control of the first clutch in a state where engine 200 is activated is instructed by third control unit 150. This is executed (step S05), and the first clutch 710 is engaged (step S06). Below, with reference to FIG. 11, the engagement control of the 1st clutch 710 in the state which the engine 200 started is demonstrated. FIG. 11 is a collinear diagram (No. 1) showing the synchronization control when the first clutch is engaged.

  In FIG. 11, when the first clutch 710 is engaged, the second clutch 720 is first engaged. That is, the ring gear R1 and the carrier C1 are connected, and the power split mechanism 300 can rotate integrally. Subsequently, torque is output from the engine 200 to increase the rotational speed of the engaging portion (that is, the rotational speed of the ring gear R1). At this time, regeneration is performed on the sun gear S1 side by taking a reaction force with MG1. That is, in MG1, power generation is performed using the power of engine 200.

  When the rotation speed of the first clutch 710 is synchronized, the engagement is actually executed. Since such engagement control is performed in a state where the engine 200 is activated, it is possible to create a state in which the torque and the rotational speed are relatively stable. Therefore, the controllability in the synchronous control of the first clutch 710 can be improved. Moreover, since regeneration is performed in MG1, it is possible to prevent the suspension of the coupling control of the first clutch 710 due to power shortage. Furthermore, since power generation by MG2 is not necessary, energy efficiency can be improved.

  Returning to FIG. 10, when the rotational speed of the engine 200 is less than the predetermined threshold value (step S04: NO), it is determined whether the engine 200 is activated (step S07). If the engine 200 is activated (step S07: YES), fuel injection is stopped (step S08). That is, the operation of the engine 200 is stopped. On the other hand, when the engine is not started (step S07: NO), the process of step S08 described above is omitted.

  As a result, when the rotational speed of the engine 200 is less than the predetermined threshold, the first clutch 710 is engaged with the engine not started. Below, with reference to FIG. 12, the engagement control of the 1st clutch 710 in the state which the engine 200 has not started is demonstrated. FIG. 12 is a collinear diagram (No. 2) showing the synchronization control when the first clutch is engaged.

  In FIG. 12, when the first clutch 710 is engaged, the second clutch 720 is first engaged. That is, the ring gear R1 and the carrier C1 are connected, and the power split mechanism 300 can rotate integrally. Subsequently, the rotational speed is detected from a MG1 resolver or the like with relatively high accuracy, and synchronous control is performed using the rotational speed. That is, here, synchronous control can be executed with high accuracy using the power of MG1. The reason why the rotational speed of MG1 can be used in this way is that the power split mechanism 300 is integrally rotated by the engagement of the second clutch 720.

  When the rotation speed of the first clutch 710 is synchronized, the engagement is actually executed while the engine 200 is not started. Here, it is assumed that the first clutch 710 is engaged with the engine 200 activated when the rotational speed of the engine 200 is less than a predetermined threshold. In this case, the engine 200 is coupled to the drive shaft 500 in a state where the engine 200 cannot rotate independently. For this reason, in the engine 200, the occurrence of misfire, resonance, and the like is high, and the drivability is expected to deteriorate due to the occurrence. In the engagement control according to the present embodiment, various problems occurring in the engine 200 as described above can be prevented.

  Returning to FIG. 10 again, when the first clutch 710 is engaged, it is determined whether or not the engine 200 is activated at this time (step S09). That is, it is determined whether the engagement control of the first clutch 710 is performed in a state where the engine 200 is activated or in a state where the engine 200 is not activated.

  Here, when it is determined that the engine 200 is not activated (step S09: NO), the rotation speed detection unit 170 detects the rotation speed of the engine 200 (step S10). That is, unlike the rotation speed estimation unit 130, the rotation speed is not estimated without engaging the first clutch 710, but the rotation speed when the first clutch 710 is actually engaged is detected. .

  When the rotational speed of engine 200 is detected, it is determined whether or not the detected rotational speed is equal to or greater than a predetermined threshold value (step S11). The predetermined threshold here is typically set to be the same as the value for the estimated number of rotations (that is, the predetermined threshold used in the process of step S04). However, it is not always necessary to set the same value completely, and different values including some margins may be set.

  When it is determined that the detected rotational speed of the engine 200 is equal to or greater than a predetermined threshold (step S11: YES), the engine 200 that has been stopped is started by the start control unit 180 (step S12). If the number of revolutions of engine 200 after engagement of first clutch 710 is equal to or greater than a predetermined threshold value, it is considered that no malfunction occurs even if engine 200 is started. Therefore, it is possible to suitably realize traveling using the power output from engine 200.

  As described above, according to the hybrid vehicle control device of the present embodiment, it is possible to suitably switch the power transmission mode using the first clutch 710 and the second clutch 720.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The control device is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 11 ... PCU, 12 ... Battery, 13 ... Accelerator opening degree sensor, 14 ... Vehicle speed sensor, 100 ... ECU, 110 ... Mode change instruction | indication part, 120 ... 1st control part, 130 DESCRIPTION OF SYMBOLS ... Rotation speed estimation part 140 ... 2nd control part, 150 ... 3rd control part, 160 ... Mode switching control part, 170 ... Rotation speed detection part, 180 ... Start-up control part, 200 ... Engine, 205 ... Crankshaft, 300 DESCRIPTION OF SYMBOLS ... Power split mechanism, 310 ... Sun gear shaft, S1 ... Sun gear, C1 ... Carrier, R1 ... Ring gear, MG1 ... Motor generator, MG2 ... Motor generator, 400 ... Input shaft, 500 ... Drive shaft, 600 ... Deceleration mechanism, 710 ... No. 1 clutch, 720 ... 2nd clutch

Claims (3)

A power element including a first motor, a second motor, and an internal combustion engine;
A drive shaft for transmitting power from the power element to the axle;
A differential rotation including a first rotating element connected to the first electric motor, a second rotating element connected to the second electric motor and the drive shaft, and a third rotating element connected to the internal combustion engine. A power transmission mechanism having a plurality of possible rotating elements;
A first clutch capable of disconnecting and coupling the second rotating element with the second electric motor and the drive shaft;
A device for controlling a hybrid vehicle comprising: a second clutch capable of separating and coupling two rotating elements among the first rotating element, the second rotating element, and the third rotating element;
Switching means for switching the power transmission mode by controlling the coupling state of the first clutch and the second clutch, respectively;
When the switching means switches from the disconnected state to the connected state, the switching means controls the switching means to connect the second clutch with the first clutch disconnected. 1 control means;
A rotational speed estimating means for estimating a rotational speed of the internal combustion engine after the first clutch is engaged, with the first clutch disengaged;
When the rotational speed of the internal combustion engine estimated by the rotational speed estimation means is less than a predetermined threshold value, the switching means is controlled so that the first clutch is engaged in a state where the internal combustion engine is not started. A control device for a hybrid vehicle, comprising: a second control means. A rotational speed detection means for detecting the rotational speed of the internal combustion engine after engagement of the first clutch when the first clutch is engaged in a state where the internal combustion engine is not activated;
The start control means for starting the internal combustion engine when the rotational speed of the internal combustion engine detected by the rotational speed detection means is equal to or greater than a predetermined threshold value. Control device for hybrid vehicle.   When the rotational speed of the internal combustion engine estimated by the rotational speed estimation means is greater than or equal to a predetermined threshold, the internal combustion engine is started and the first motor is regenerated and the first clutch is coupled. The hybrid vehicle control device according to claim 1, further comprising third control means for controlling the switching means.

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