JP2012081793A - Control device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve driving efficiency of a hybrid vehicle capable of switching a power transmission mode.SOLUTION: A control device (100) for the hybrid vehicle controls the hybrid vehicle provided with power elements (200, MG1, MG2), a drive shaft (500), a power transmission mechanism (300), a first clutch (710), a second clutch (720), and a brake (730). The control device for the hybrid vehicle includes: a switching means (140) capable of mutually switching between a first power transmission mode for disconnecting the first clutch and engaging the second clutch, and a second power transmission mode of disconnecting the first clutch and fixing a second rotation element by the brake; an estimation means (120) for estimating power losses of the first power transmission mode and the second power transmission mode, respectively; and a switching control means (130) for controlling the switching means to switch to one of the power transmission modes, whichever is lower in power loss.

Description

  The present invention relates to a technical field of a hybrid vehicle control device that controls a hybrid vehicle configured to be capable of realizing various power transmission modes.

  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 switching operation of the power transmission mode described above is realized by providing a clutch or the like that can be engaged and released on a planetary gear or the like that is configured as a power transmission mechanism. For example, Patent Document 1 proposes a technique for realizing a series mode by engaging a clutch provided between a carrier and a ring gear constituting a planetary gear and releasing a clutch between the output shaft and the ring gear. . Further, Patent Document 2 proposes a technique for similarly realizing the series mode by fixing the ring gear and releasing the clutch between the output shaft and the ring gear.

JP 2002-078106 A JP 2003-237392 A

  The series mode realized by engaging the clutch between the carrier and the ring gear described above and the series mode realized by fixing the ring gear can be made compatible by combining a plurality of clutches. Can be realized. However, the above-described two types of series modes have a difference in power loss depending on the traveling state of the vehicle. Therefore, even if two types of series modes can be achieved at the same time, if the mode switching operation is not performed under appropriate conditions, there is a technical problem that the driving efficiency may be deteriorated. Have.

  The present invention has been made in view of the above-described problems, for example, and it is an object of the present invention to provide a hybrid vehicle control device capable of effectively increasing the driving efficiency of a hybrid vehicle capable of switching a power transmission mode. To do.

  In order to solve the above problems, the hybrid vehicle control device of the present invention is connected to the internal combustion engine, a power element including the first motor and the second motor, and the second motor, and outputs power to the axle. A plurality of rotations that can be differentially rotated with each other, including a first rotating element coupled to the first motor, a second rotating element coupled to the drive shaft, and a third rotating element coupled to the internal combustion engine. A power transmission mechanism having an element; a first clutch capable of disconnecting and coupling the second rotating element and the drive shaft; and the first rotating element, the second rotating element, and the third rotating element coupled to each other. And a second clutch capable of rotating integrally and a brake capable of fixing and releasing the second rotating element, the apparatus controlling a hybrid vehicle, wherein the first clutch is disengaged. A first power transmission mode in which the second clutch is engaged and the second rotating element is released from the brake; and the second clutch is released and the second rotating element is released by the brake. Switching means capable of mutually switching the second power transmission mode for fixing the power, and estimating the power loss when the power transmission mode is switched to the first power transmission mode and the second power transmission mode, respectively. An estimation unit; and a switching control unit that controls the switching unit so as to switch to the power transmission mode having the smaller estimated power loss out of the first power transmission mode and the second power transmission mode. Prepare.

  In the hybrid vehicle according to the present invention, various modes regardless of, for example, fuel type, fuel supply mode, fuel combustion mode, intake / exhaust system configuration, and cylinder arrangement, can be used as power elements capable of supplying power to the drive shaft. And a vehicle including at least a first electric motor and a second electric motor that can be configured as a motor generator such as a motor generator. Among the power elements described above, the internal combustion engine and the first electric motor are connected to the drive shaft via a power transmission mechanism including a plurality of rotating elements (preferably gears).

  The power transmission mechanism includes a first rotating element connected to the first electric motor, a second rotating element connected to the drive shaft, and a third rotating element connected to the internal combustion engine. In short, it is a physical state that defines the rotation mode, including whether or not it is rotatable and whether or not it is connected to other rotating elements, etc.) Transmit power. 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 includes a first clutch capable of disconnecting and coupling the power transmission mechanism and the drive shaft described above. The first clutch is configured, for example, as a dog clutch or the like, and realizes power transmission from the power transmission mechanism to the drive shaft by engaging two engaging portions that are rotatable with each other. Power transmission from to the drive shaft is cut off.

  Further, the hybrid vehicle according to the present invention includes a second clutch capable of integrally rotating the first rotation element, the second rotation element, and the third rotation element in the power transmission mechanism. The second clutch is configured as, for example, a dog clutch, etc., and the two engaging portions that can be rotated are engaged with each other so that the first rotating element, the second rotating element, and the third rotating element are coupled to each other. It is possible to rotate it.

  Note that the second clutch does not need to couple all of the first rotating element, the second rotating element, and the third rotating element to each other. If at least two rotating elements are coupled, each rotating element is integrated. Can be rotated. That is, the second clutch may couple the first rotating element and the second rotating element to each other, may couple the second rotating element and the third rotating element to each other, or may combine the third rotating element and the first rotating element. The rotating elements may be coupled to each other.

  The hybrid vehicle according to the present invention further includes a brake capable of fixing and releasing the second rotating element. The brake can control its rotational movement by fixing and releasing the second rotating element. That is, the “fixing” and “release” here are intended for the rotation operation of the second rotation element (in other words, the operation for transmitting power).

  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 control device according to the present invention includes switching means for switching the power transmission mode by controlling each of the first clutch, the second clutch, and the brake. The switching means disconnects the first clutch and engages the second clutch to release the second rotating element from the brake, and disconnects the first clutch and releases the second clutch to release the second clutch. The second power transmission mode for fixing the rotating element can be switched mutually. Note that the switching means is typically configured to be capable of switching to a power transmission mode other than the first power transmission mode and the second power transmission mode (for example, a power transmission mode in which the first clutch is engaged). The

  According to the first power transmission mode, since the second clutch is engaged, the first rotation element, the second rotation element, and the third rotation element included in the power transmission mechanism rotate integrally. However, since the first clutch is disengaged, the power output from the internal combustion engine and the first electric motor is not output to the drive shaft, and the drive shaft is connected to the second electric motor connected without the power transmission mechanism. Power is output. In addition, the electric power obtained by regeneration of a 1st motor can be used as a motive power of a 2nd motor.

  According to the second power transmission mode, the second rotating element is fixed by the brake, and the rotation is stopped. However, since the first clutch is released, the drive shaft can rotate, and the drive shaft can output power from the second electric motor as in the first power transmission mode.

  Here, the control apparatus for a hybrid vehicle according to the present invention particularly in the case where the power transmission mode is switched to the first power transmission mode by the estimating means before the power transmission mode is switched by the switching means. The power loss when switching to the power loss and the second power transmission mode is estimated. Here, “power loss” means power that is lost before being output to the drive shaft among the power output from each of the power elements.

  The estimation means is, for example, a power loss obtained from the rotational speed and output torque of the first motor (that is, a power loss of the first motor) or a power loss obtained from the engagement states of the first clutch, the second clutch, and the brake ( That is, the power loss in the power transmission mechanism is estimated. However, it is possible to appropriately set which parameter is used to estimate the power loss. For example, correction may be performed based on the temperature of each power element. The power loss may be estimated using a stored map or the like, or may be estimated by a real-time calculation process.

  When the power loss in the case of switching to the first power transmission mode and the second power transmission mode is estimated, the switching means is controlled by the switching control means, and the first power transmission mode and the second power transmission mode are controlled. Of these, switching to the power transmission mode with small power loss is performed. That is, when the power loss at the time of switching to the first power transmission mode is estimated as a smaller value, the power transmission mode of the hybrid vehicle is switched to the first power transmission mode. On the other hand, when the power loss at the time of switching to the second power transmission mode is estimated as a smaller value, the power transmission mode of the hybrid vehicle is switched to the second power transmission mode.

  The power loss in each power transmission mode varies depending on the traveling state of the hybrid vehicle. For this reason, if there is a scene where the power loss in the first power transmission mode is smaller, there is also a scene where the power loss in the second power transmission mode is smaller. In the present invention, since the power loss of the power transmission mode after the switching is estimated in advance before actually switching the power transmission mode, an appropriate power transmission mode is selected according to the traveling state of the hybrid vehicle. be able to.

  As described above, according to the hybrid vehicle control device of the present invention, it is possible to effectively increase the driving efficiency of the hybrid vehicle.

  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. It is a mimetic diagram which illustrates one section composition of an engine. It is a block diagram which shows the structure of ECU. It is an alignment chart which shows the operation point of the 1st mode. It is an alignment chart which shows the operation point of the 2nd mode. It is an alignment chart which shows the operation point of the 3rd mode. It is a collinear diagram which shows the operating point of 4th mode. It is a flowchart which shows operation | movement of the control apparatus of a hybrid vehicle. It is a map regarding the rotation speed and torque of MG1. It is a collinear diagram which shows the power loss in a power split device (the 1). It is a collinear diagram which shows the power loss in a power split device (the 2). It is a collinear diagram which shows the power loss in a power split device (the 3). It is a collinear diagram which shows the power loss in a power split device (the 4).

  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 execute various controls in the hybrid vehicle 1 according to a control program stored in, for example, a ROM.

  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 detect an accelerator opening Ta, which is 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 FIG. 2, the hybrid drive apparatus 10 mainly includes an engine 200, a power split mechanism 300, an MG2 reduction mechanism 350, a motor generator MG1 (hereinafter referred to as “MG1” as appropriate), and a motor generator MG2 (hereinafter referred to as “MG2” as appropriate). The input shaft 400, the drive shaft 500, the speed reduction mechanism 600, and the clutch 710.

  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 one cross-sectional configuration of the engine.

  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, the motor generator MG1 is a motor generator that is an example of the “motor” according to the present invention, and has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. It has a configuration with. Similarly to motor generator MG1, motor generator MG2 has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. 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.

  Power split mechanism 300 provided between engine 200 and MG1 and the drive shaft is an example of the “power transmission mechanism” of the present invention, and is configured as a planetary gear. Similarly, the MG2 reduction mechanism 350 provided between the MG2 and the drive shaft 500 is also configured as a planetary gear.

  The power split mechanism 300 is an example of the “second rotating element” of the present invention provided concentrically on the outer periphery of the sun gear S1 and the sun gear S1 that is an example of the “first rotating element” of the present invention provided at the center. A third ring gear R1, a plurality of pinion gears P1 that are arranged between the sun gear S1 and the ring gear R1 and revolve while rotating on the outer periphery of the sun gear S1, and the "third rotation" of the present invention that supports the rotation shaft of each pinion gear. And a carrier C1 as an example of “element”.

  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 first clutch 710, the drive shaft 500, and the speed reduction mechanism 600, and the rotational speed thereof is the rotational speed Nmg2 of the MG2 (hereinafter referred to as “MG2 rotational speed Nmg2” as appropriate). And have a unique 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 disconnects the connection between the ring gear R1 and the drive shaft 500 and MG2 according to the engaged state. Can be combined. 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.

  Further, a second clutch 720 is provided between the sun gear S1 and the ring gear R1, and the connection between the sun gear S1 and the ring gear R1 can be disconnected and coupled depending on the engaged state. Specifically, when the second clutch 720 is disengaged, the sun gear S1 and the ring gear R1 rotate separately. On the other hand, when the second clutch 720 is engaged, the sun gear S1 and the ring gear R1 rotate integrally. For this reason, each rotation element in the power transmission mechanism 300 becomes the same rotation. In addition, the 2nd clutch 720 is not restricted to the structure mentioned above, What is necessary is just to connect at least 2 rotation element among each rotation element. Specifically, the coupling between the ring gear R1 and the carrier C1 may be coupled, or the coupling between the sun gear S1 and the carrier C1 may be coupled. If two of the rotating elements are connected to each other, the rotating elements can be rotated together.

  In addition, the ring gear R1 is provided with a brake 730 for fixing its rotational operation. One of the brakes 730 is fixed to the fixed element, and the other is engaged with the ring gear R1, thereby fixing the rotational operation of the ring gear R1.

  Next, a specific configuration of the ECU 100, which is an example of a control device for a 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.

  In FIG. 4, the ECU 100 includes a required driving force determination unit 110, a power loss estimation unit 120, a power transmission mode determination unit 130, and a power transmission mode switching unit 140.

  The required driving force determination unit 110 determines whether or not the input required driving force (that is, torque to be output to the drive shaft 500) is smaller than a predetermined threshold value. Here, the “predetermined threshold value” is a threshold value for determining whether the power transmission mode of the hybrid vehicle 1 is set to the series mode or the parallel mode. Stored in the memory of the unit 110.

  The power loss estimator 120 is an example of the “estimator” of the present invention, and the power transmission mode is set to the series mode (specifically, based on the input operation information (for example, information indicating the rotation speed and output torque) of the MG1). Specifically, the power loss when switching to the first mode and the second mode described later is estimated. A specific method for estimating the power loss will be described in detail later.

  The power transmission mode determination unit 130 is an example of the “switching control unit” of the present invention, and determines the power transmission mode to be realized according to the power loss estimated by the power loss estimation unit 120. Specifically, the power transmission mode with the smaller power loss of the first mode and the second mode is determined as the power transmission mode to be realized.

  The power transmission mode switching unit 140 is an example of the “switching unit” of the present invention, and controls the power split mechanism 300 to realize the power transmission mode determined by the power transmission mode determination unit 130. That is, by controlling the engagement states of the first clutch 710, the second clutch 720, and the brake 730, the state of the power split mechanism 300 is changed so that the determined power transmission mode is realized.

  Note that the ECU 100 is an integrated electronic control unit that includes the above-described units, and all the operations related to the above-described parts 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, four power transmission modes that can be realized in the hybrid vehicle according to the present embodiment will be described with reference to FIGS. FIG. 5 is a collinear diagram showing operating points in the first mode, and FIG. 6 is a collinear diagram showing operating points in the second mode. FIG. 7 is a collinear diagram showing operating points in the third mode, and FIG. 8 is a collinear diagram showing operating points in the fourth mode.

  In FIG. 5, in the first mode, the first clutch 710 and the second clutch 720 are disconnected, and the ring gear R <b> 1 is fixed by the brake 730. Therefore, no power is output from the ring gear R1 to the drive shaft 500. In the first mode, the power output from the engine 200 is regenerated at the MG 1 to become electric power, and the power is output to the drive shaft 500 from the MG 2 using the electric power obtained by the regeneration as the power. The first mode is an example of the “second power transmission mode” in the present invention.

  In FIG. 6, in the second mode, since the first clutch 710 is disconnected, no 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 power output from the MG 2 is transmitted to the drive shaft 500. In the second mode, the second clutch 720 is engaged, and the ring gear R1 is released from the brake 730. Therefore, each rotation element (that is, sun gear S1, carrier C1, and ring gear R1) of power split device 300 rotates integrally. The first mode is an example of the “first power transmission mode” in the present invention.

  In FIG. 7, in the third mode, since the first clutch 710 is coupled, power is output from the ring gear R <b> 1 of the power split mechanism 300 to the drive shaft 500. For this reason, the hybrid vehicle 1 travels with the power from the engine 200. In the third mode, since the second clutch is released, the rotating elements of the power split mechanism 300 have different rotational speeds. In the third mode, 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 FIG. 8, 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 R <b> 1 in the power split mechanism 300. For this reason, the hybrid vehicle 1 travels with the power from the engine 200. In the fourth mode, since the second clutch is engaged, the rotating elements of the power split mechanism 300 rotate integrally as in the second mode described above.

  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 by the hybrid vehicle control device according to the present embodiment and the effects thereof will be described with reference to FIG. FIG. 9 is a flowchart showing the operation of the control device for the hybrid vehicle.

  In FIG. 9, when the control apparatus for a hybrid vehicle according to the present embodiment operates, first, the required driving force determination unit 110 determines whether or not the required driving force is smaller than a predetermined threshold value (step S01). If the required driving force is greater than or equal to the threshold value (step S01: NO), the parallel HV mode (that is, the third mode or the fourth mode) suitable when the power transmission mode of the hybrid vehicle 1 requires a relatively high driving force. Mode) (step S02). More specifically, the first clutch 710 is engaged.

  On the other hand, when the required driving force is greater than or equal to the threshold value (step S01: YES), the power loss estimation unit 120 causes the power loss when the power transmission mode is switched to the first mode and the power when the power transmission mode is switched to the second mode. Each loss is estimated (step S03).

  Subsequently, in the power transmission mode determination unit 130, the power loss when switching to the first mode and the power loss when switching to the second mode are compared with each other, and the power loss in any power transmission mode is small. Is determined (step S04).

  When the power loss in the first mode is smaller (step S04: YES), the power transmission mode switching unit 140 switches the power transmission mode to the first mode (step S05). Specifically, the first clutch 710 and the second clutch 720 are released, and the ring gear R1 is fixed by the brake 730. On the other hand, when the power loss in the second mode is smaller (step S04: NO), the power transmission mode switching unit 140 switches the power transmission mode to the second mode (step S06). Specifically, the first clutch 710 and the brake 730 are released, and the second clutch 720 is engaged. Therefore, in this embodiment, it is possible to selectively realize a series mode with smaller power loss according to the traveling state of the vehicle.

  Hereinafter, a more specific method for estimating power loss will be described in detail with reference to FIGS. 10 to 14. FIG. 10 is a map relating to the rotational speed and torque of MG1, and FIGS. 11 to 12 are collinear charts showing power loss in the power split mechanism.

In FIG. 10, the power loss in MG1 tends to increase as the rotational speed and output torque increase. Here, the respective operating points of the power split mechanism 300 at points A and A ′, which are relatively small operating points of the generated power shown in the figure, and at points B and B ′, where the generated power is relatively large, are considered. 11 and 12, a point A indicates an operating point in the first mode, a point A ′ indicates an operating point in the second mode, and each power element and the driving shaft 500 respectively indicate the power indicated by an arrow in the figure. Is output (the length of the arrow corresponds to the magnitude of the power).

  13 and 14, point B indicates the operating point of the first mode, and point B ′ indicates the operating point of the second mode. Each power element and the drive shaft 500 respectively indicate the power indicated by the arrow in the figure. Is output.

  In the power loss determination unit 110, the power loss derived based on the operating points shown in FIGS. 11 to 14 with respect to the power loss of MG1 as shown in FIG. 10 (that is, the power loss in the power split mechanism 300). The map added with is stored. Further, since the power loss may change depending on the temperature of MG1, correction according to the detected temperature may be performed.

  Returning to FIG. 10, comparing point A and point A ′, it can be seen that the power loss at point A ′ is smaller than the power loss at point A. Specifically, the point A ′ exists in a region where the power loss is smaller than that of the point A (see the region partitioned by the solid line in the figure). Therefore, when the generated power is relatively small, the second mode in which the rotational speeds of the power elements are the same is realized.

  On the other hand, comparing point B and point B ′, it can be seen that the power loss at point B is smaller than the power loss at point B ′. Specifically, the point B exists in a region where the power loss is smaller than the point B ′. Therefore, when the generated power is relatively large, the first mode in which the ring gear R1 is fixed is realized.

  As described above, according to the hybrid vehicle control device of the present embodiment, it is possible to travel in the power transmission mode with smaller power loss, so that the driving efficiency of the hybrid vehicle 1 can be effectively increased. Is possible.

  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 ... Required drive force determination part, 120 ... Power loss estimation part, DESCRIPTION OF SYMBOLS 130 ... Power transmission mode determination part, 140 ... Power transmission mode switching part, 200 ... Engine, 205 ... Crankshaft, 300 ... Power split mechanism, 310 ... Sun gear shaft, 350 ... MG2 reduction mechanism, S1 ... Sun gear, C1 ... Carrier, R1 ... ring gear, MG1 ... motor generator, MG2 ... motor generator, 400 ... input shaft, 500 ... drive shaft, 600 ... deceleration mechanism, 710 ... first clutch, 720 ... second clutch, 730 ... brake

Claims (1)

An internal combustion engine, and a power element including a first electric motor and a second electric motor;
A drive shaft connected to the second electric motor for outputting power to the axle;
A plurality of rotational elements capable of differentially rotating with each other, including a first rotational element coupled to the first electric motor, a second rotational element coupled to the drive shaft, and a third rotational element coupled to the internal combustion engine A power transmission mechanism having
A first clutch capable of disconnecting and coupling the second rotating element and the drive shaft;
A second clutch capable of rotating integrally with the first rotating element, the second rotating element, and the third rotating element;
A device for controlling a hybrid vehicle including a brake capable of fixing and releasing the second rotating element,
A first power transmission mode for disengaging the first clutch and engaging the second clutch to release the second rotating element from the brake; and disengaging the first clutch and releasing the second clutch to release the brake. And a switching means capable of mutually switching a second power transmission mode for fixing the second rotating element.
Estimating means for estimating a power loss when the power transmission mode is switched to the first power transmission mode and the second power transmission mode, respectively;
Switching control means for controlling the switching means so as to switch to the power transmission mode in which the estimated power loss is smaller among the first power transmission mode and the second power transmission mode. A control device for a hybrid vehicle.

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