JP2012144172A - Controller for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller for a hybrid vehicle, capable of adjusting NV (noise and vibration) suppression and response improvement according to an intention of a driver, or the like.SOLUTION: The controller for a hybrid vehicle includes: an engine; a first dynamo-electric machine; a second dynamo-electric machine; a power transmission mechanism; and a control means. The power transmission mechanism includes a plurality of rotating elements capable of being differentially rotated with each other. The control means starts the engine after a clutch is engaged, when a traveling mode is switched from a first traveling mode to a second traveling mode. In a state where suppression of noise or/and vibration is to be prioritized, the control means reduces an engine speed to nearly zero, and then brings the clutch into an engagement state to start the engine.

Description

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

  Conventionally, in addition to the internal combustion engine (engine), a first rotating electrical machine that mainly functions as a generator, and a second rotating electrical machine that mainly functions as an electric motor that supplies power to a drive shaft connected to drive wheels; There is known a hybrid vehicle including a power distribution mechanism that distributes output torque of an internal combustion engine to a first rotating electrical machine side, a drive shaft, and a second rotating electrical machine side.

  For example, Patent Document 1 discloses a hybrid vehicle that includes an engine and first and second rotating electric machines and that can switch a coupling state between the second rotating electric machine and the engine by a clutch. This hybrid vehicle performs a so-called series-parallel hybrid travel when the clutch is engaged, and disengages the engine to perform an EV (electric vehicle) travel by the second rotating electrical machine. Further, in Patent Document 2, when shifting from the continuously variable transmission mode to the fixed transmission gear ratio mode, the speed is changed while satisfying restrictions on NV (Noise and Vibration), and economic performance is improved by input from the driver. In the case where priority is given, a technique for shifting the speed while relaxing restrictions on NV is disclosed. Further, Patent Document 3 discloses that when the low noise and low noise mode switch is on, the traveling region set to the low speed stage is increased.

JP 2000-209706 A JP 2009-214828 A JP 2006-231977 A

  In a hybrid vehicle in which the coupling state between the second rotating electrical machine and the engine can be switched by the clutch, the engine is started by engaging the clutch from the EV traveling state in which the clutch is in the released state, and the first rotating electrical machine When synchronizing the rotations of the engagement elements of the clutch, vibrations may occur if the engine speed is within a predetermined range. On the other hand, depending on the driver, it may be desired to improve the responsiveness by allowing vibration.

  The present invention has been made to solve the above-described problems, and provides a hybrid vehicle control device capable of adjusting NV suppression and responsiveness improvement in accordance with the driver's intention and the like. This is the issue.

  In one aspect of the present invention, the engine, the first rotating electrical machine, the second rotating electrical machine, the first rotating element coupled to the first rotating electrical machine, the second rotating electrical machine, and the drive shaft are clutched. A power transmission mechanism comprising a plurality of rotating elements that are differentially rotatable with each other, including a second rotating element that is coupled to the engine, and a third rotating element that is coupled to the engine, and the clutch is released, When the travel mode is switched from the first travel mode in which the engine is stopped and the second rotating electrical machine travels to the second travel mode in which the clutch is engaged and the engine is driven to travel. Control means for starting the engine after engaging the engine, and in a state where priority should be given to suppression of noise and / or vibration, the control means sets the engine speed to approximately 0 and then starts the clutch. It was in engagement, thereby starting the engine.

  The control apparatus for a hybrid vehicle is mounted on the hybrid vehicle and includes an engine, a first rotating electrical machine, a second rotating electrical machine, a power transmission mechanism, and control means. The power transmission mechanism includes a plurality of rotating elements that are differentially rotatable with respect to each other. Specifically, the power transmission mechanism includes a first rotating element coupled to the first rotating electrical machine, a second rotating element coupled to the second rotating electrical machine and the drive shaft via a clutch, and a first rotating element coupled to the engine. 3 rotation elements. Here, “connected” includes a structure that directly transmits power (rotation), and also includes a structure that indirectly transmits power via one or more members. The control means is, for example, an ECU (Electronic Control Unit), and when the travel mode is switched from the first travel mode to the second travel mode, the engine is started after engaging the clutch. The first travel mode is a travel mode when the clutch is in a released state, and indicates EV travel with the engine stopped. The second traveling mode is a traveling mode in which the clutch is engaged and the engine is driven. In this case, the power output from the engine is divided into two by the power transmission mechanism, and part of the mechanical power is mechanical power. As it is output to the drive shaft, the remainder is converted into electric power and output to the drive shaft. Then, in a state where priority should be given to suppression of noise or / and vibration, the control means sets the engine speed to substantially 0, then engages the clutch and starts the engine. As described above, when priority is given to the suppression of NV, the control device for the hybrid vehicle suppresses engine vibration by setting the engine speed to substantially zero, and highly accurately synchronizes the engagement elements of the clutch. And the occurrence of a shock when the clutch is engaged can be suppressed.

  One aspect of the hybrid vehicle control device further includes an interface for allowing the user to designate whether noise or / and vibration suppression should be prioritized. The interface is, for example, a switch. By doing in this way, the control apparatus of a hybrid vehicle can determine which of the suppression of NV and improvement of responsiveness should be prioritized according to a user's (driver | operator's) intention.

  In one aspect of the hybrid vehicle control device, the control means is in a case where the differential rotational speed of the engagement element of the clutch is equal to or less than a predetermined value, and is not in a state where priority should be given to suppression of noise or / and vibration. In this case, the clutch is brought into an engaged state without performing control for synchronizing the rotation of the engaging element of the clutch. Thereby, the control apparatus of a hybrid vehicle can make a clutch into an engagement state at an early stage, when a user wants to allow a vibration and to accelerate.

An example of the schematic block diagram of the hybrid vehicle which concerns on embodiment is shown. It is an example of the schematic block diagram of a hybrid drive device. It is an example of the flowchart which shows the process sequence which concerns on 1st Embodiment. It is an example of the flowchart which shows the process sequence which concerns on 2nd Embodiment. It is an operation alignment chart which illustrates one operation state of a hybrid drive device. It is an example of the flowchart which shows the process sequence which concerns on 3rd Embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[overall structure]
First, an example of the configuration of a hybrid vehicle 1 to which the hybrid vehicle control device according to the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a hybrid vehicle 1. The hybrid vehicle 1 includes an ECU 100, a PCU (Power Control Unit) 11, a battery 12, an accelerator opening sensor 13, a vehicle speed sensor 14, a rotation speed sensor 15, and a hybrid drive device 10.

  The ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an A / D (Analog to Digital) converter, an input / output interface, and the like. It is an electronic control unit for controlling. The ECU 100 executes control described later according to a control program stored in the ROM. The ECU 100 functions as a “control unit” in the present invention. Note that the physical, mechanical, and electrical configurations of the control means according to the present invention are not limited to this. For example, the control means includes a plurality of computers such as a plurality of ECUs, various processing units, various controllers, or a microcomputer device. It may be a system or the like.

  The hybrid drive device 10 drives the hybrid vehicle 1 by supplying driving torque as driving force to the left axle SFL (corresponding to the left front wheel FL) and the right axle SFR (corresponding to the right front wheel FR), which are the axles of the hybrid vehicle 1. Drive unit. The detailed configuration of the hybrid drive device 10 will be described later.

  The PCU 11 includes an inverter (not shown), and is a control unit that controls power input / output between the battery 12 and each motor generator described later, or power input / output between the motor generators not via the battery 12. is there. Specifically, the PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to each motor generator, and converts the AC power generated by each motor generator into DC power and supplies it to the battery 12. To do. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 is a battery unit that has a configuration in which a plurality of unit battery cells are connected in series and functions as a power supply source related to power for powering each motor generator.

  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 that detects 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 rotational speed sensor 15 generates an output pulse indicating the rotational speed of the engine 20 (also referred to as “engine rotational speed Ne”). The rotation speed sensor 15 supplies an output pulse to the ECU 100 by a detection signal.

[Configuration of hybrid drive unit]
Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the hybrid drive device 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof is omitted as appropriate.

  In FIG. 2, the hybrid drive device 10 is abbreviated as an engine 20, a power split mechanism 30, a motor generator MG1 (hereinafter abbreviated as “motor MG1” as appropriate), and a motor generator MG2 (hereinafter abbreviated as “motor MG2” as appropriate). ), An input shaft 40, a clutch CL, a brake BR, a speed reduction mechanism 60, and an oil pump 70.

  The engine 20 functions as a main power source of the hybrid vehicle 1. The engine torque “Te” that is the output power of the engine 20 is connected to the input shaft 40 of the hybrid drive device 10 via a crankshaft (not shown).

  The motor MG1 is a motor generator as an example of the “first rotating electrical machine” according to the present invention, which has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy.

  The motor MG2 is a motor generator as an example of a “second rotating electrical machine” according to the present invention having a larger physique than the motor MG1, and, like the motor MG1, a power running function that converts electrical energy into kinetic energy, and kinetic energy And a regenerative function for converting the energy into electrical energy. Unlike motor MG1 and engine 20, motor MG2 operates its output torque (hereinafter referred to as “MG2 torque Tmg2”) on the drive shaft of hybrid vehicle 1 (hereinafter referred to as “drive shaft OUT”). It is possible to make it. Therefore, the motor MG2 can assist the travel of the hybrid vehicle 1 by applying torque to the drive shaft OUT, or can perform power regeneration by inputting the torque from the drive shaft OUT. The MG2 torque Tmg2 is controlled by the ECU 100 via the PCU 11 together with the input / output torque of the motor MG1 (hereinafter referred to as “MG1 torque Tmg1”).

  The motor MG1 and the motor MG2 function as a synchronous motor generator, and include, for example, a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field.

  The power split mechanism 30 is a composite planetary gear mechanism that is an example of the “power transmission mechanism” according to the present invention. The power split mechanism 30 includes a sun gear S1 as an example of the “first rotating element” according to the present invention provided in the center portion, and a “second rotating element according to the present invention provided concentrically on the outer periphery of the sun gear S1. , A plurality of pinion gears “P1” (not shown) that are arranged between the sun gear S1 and the ring gear R1 and revolve around the outer periphery of the sun gear S1, and the rotations of the pinion gears “P1”. And a carrier C1 as an example of the “third rotating element” according to the present invention, which supports the shaft.

  Here, the sun gear S1 is connected to the rotor of the motor MG1 so as to share the rotation axis, and the rotation speed is equivalent to the rotation speed of the motor MG1 (hereinafter referred to as “MG1 rotation speed Nmg1”). It is.

  Ring gear R1 is connected to engagement element RCL of clutch CL. Further, the other engagement element OCL of the clutch CL is coupled to the speed reduction mechanism 60. Accordingly, the ring gear R1 is connected to the speed reduction mechanism 60 via the clutch CL. The rotation speed of the ring gear R1 is equivalent to the rotation speed of the engagement element RCL, and the rotation speed of the engagement element OCL is equivalent to the rotation speed of the drive shaft OUT (also referred to as “output rotation speed Nout”). Therefore, when the clutch CL is engaged, the rotation speed of the ring gear R1 is equivalent to the output rotation speed Nout.

  The carrier C1 is connected to an input shaft 40 that is connected to the crankshaft of the engine 20, and the rotation speed thereof is equivalent to the engine rotation speed Ne.

  In the power split mechanism 30, the engine torque Te supplied from the engine 20 to the input shaft 40 under the above-described configuration is applied to the sun gear S1 and the ring gear R1 by the carrier C1 at a predetermined ratio, specifically, between each gear. Distribute at a ratio according to the gear ratio. That is, the power split mechanism 30 splits the power of the engine 20 into two systems.

  Reduction mechanism 60 is connected to the rotor of motor MG2 and is connected to ring gear R1 via clutch CL. The reduction mechanism 60 transmits the rotation of the drive shaft OUT to the motor MG2 in a form that is reduced in accordance with a reduction ratio that is determined according to the gear ratio of each gear that constitutes the reduction mechanism 60. Therefore, the rotational speed of motor MG2 (hereinafter referred to as “MG2 rotational speed Nmg2”) is uniquely determined according to vehicle speed V. Further, the speed reduction mechanism 60 includes a drive shaft OUT that exhibits a rotational state that is unambiguous with the axle, a reduction gear coupled to the drive shaft OUT, and a differential. The rotational speed of each axle is transmitted to the drive shaft OUT while being decelerated by the reduction mechanism 60 according to a predetermined gear ratio.

  The oil pump 70 supplies lubricating oil to each part of the hybrid drive device 10. The oil pump 70 is driven by the power transmitted by the input shaft 40.

  Further, a rotation sensor such as a resolver is provided at a portion corresponding to the broken line frame A1. This rotation sensor is in a state of being electrically connected to ECU 100 and detects MG1 rotation speed Nmg1. The detected MG1 rotation speed Nmg1 is sent to ECU 100 at a constant or indefinite period.

  The configuration according to the embodiment relating to the “power transmission mechanism” according to the present invention is not limited to that of the power split mechanism 30. For example, the power transmission mechanism according to the present invention may be a composite planetary gear mechanism in which a plurality of planetary gear mechanisms are combined.

[Control method]
First, the control of the clutch CL executed by the ECU 100 will be described.

  When performing EV traveling, ECU 100 releases clutch CL, stops engine 20, and travels by motor MG2. Thus, ECU 100 suppresses losses due to dragging of the gears and bearings of motor MG1 and power split mechanism 30 during EV traveling by releasing clutch CL during EV traveling. The above-described EV traveling is an example of the “first traveling mode” in the present invention.

  On the other hand, the ECU 100 causes the hybrid vehicle 1 to function as a so-called series-parallel hybrid vehicle by engaging the clutch CL and driving the engine 20. That is, in this case, the hybrid vehicle 1 divides the power from the engine 20 by the power split mechanism 30, outputs one of the power to the drive shaft OUT as mechanical power, and converts the remainder to electric power by the motors MG1 and MG2. And output to the drive shaft OUT. Hereinafter, the travel mode in this case is also referred to as “series parallel travel”. Series parallel traveling is an example of the “second traveling mode” in the present invention.

  Therefore, when switching from EV traveling to series parallel traveling, the ECU 100 needs to shift the clutch CL from the released state to the engaged state. Specifically, when switching from EV traveling to series parallel traveling, the ECU 100 synchronizes the rotational speeds of the engagement elements RCL and OCL of the clutch CL (also referred to as “clutch synchronization control”) and the clutch CL. Is controlled from the disengaged state to the engaged state (also referred to as “clutch engagement control”) and control for starting the engine 20 (also referred to as “engine start control”). Here, in the clutch synchronization control, the ECU 100 specifically uses the absolute value of the differential rotation speed between the engagement element RCL and the engagement element OCL (also referred to as “clutch differential rotation speed dNcl”) as a predetermined threshold ( Also referred to as “threshold dNth”. The threshold value dNth is an upper limit value of the clutch differential rotation speed dNcl that can shift the clutch CL to the engaged state. Further, in the engine start control, the ECU 100 increases the engine speed Ne to a speed required to start the engine 20 (also referred to as “engine start speed Nes”) and starts fuel injection.

  In the following first to third embodiments, the execution order of clutch synchronization control, clutch engagement control, engine start control, etc. when switching from EV traveling to series parallel traveling will be specifically described.

<First Embodiment>
In the first embodiment, when switching from EV travel to series parallel travel, the ECU 100 performs engine start control when the engine speed Ne is equal to or higher than the engine start speed Nes, and performs the clutch during or after engine start control. Synchronous control and clutch engagement control are sequentially performed. Thereby, the ECU 100 shortens the time to acceleration and improves the responsiveness at the time of reacceleration or the like.

  This will be supplementarily described. When the travel mode is changed from the series parallel travel to the EV travel and the travel mode is switched to the series parallel travel again by reacceleration or the like while the fuel injection of the engine 20 is stopped, the engine speed Ne is equal to or higher than the engine start speed Nes. There are times when In this case, ECU 100 does not need to perform cranking of engine 20 by motor MG1.

  In consideration of the above, in this case, the ECU 100 first restarts the fuel injection of the engine 20 to start the engine 20, and performs clutch synchronization control and clutch engagement control during or after that. As a result, the ECU 100 can shorten the time required for engine start control, and can shorten the time until re-acceleration.

  FIG. 3 is an example of a flowchart illustrating a processing procedure executed by the ECU 100 in the first embodiment. The ECU 100 repeatedly executes the processing of the flowchart shown in FIG. 3 according to a predetermined cycle when executing series parallel travel.

  First, the ECU 100 determines whether or not the traveling mode should be switched from series parallel traveling to EV traveling (step S101). If the ECU 100 determines that the travel mode should be switched from the series parallel travel to the EV travel (step S101; Yes), the ECU 100 performs clutch release control (step S102). That is, in this case, the ECU 100 shifts the clutch CL from the engaged state to the released state. On the other hand, when ECU 100 determines that the travel mode should not be switched from series parallel travel to EV travel (step S101; No), the process of the flowchart ends.

  Next, in step S103, the ECU 100 determines whether or not the vehicle speed V is greater than the threshold value “Vth” (step S103). The threshold value Vth is a threshold value for determining whether or not to stop the fuel of the engine 20, and is determined in advance in consideration of, for example, the possibility of switching from EV traveling to series parallel traveling.

  If the ECU 100 determines that the vehicle speed V is greater than the threshold value Vth (step S103; Yes), the ECU 100 performs an idle operation of the engine 20 (step S104). That is, in this case, the ECU 100 determines that there is a high possibility of switching from EV traveling to series parallel traveling again, and continuously operates the engine 20 without stopping it. And ECU100 implements clutch synchronous control (step S106), when it judges that it should switch from EV driving | running | working after that to series parallel driving | running after that (step S105; Yes). As a result, the ECU 100 sets the clutch differential rotation speed dNcl to a threshold value dNth or less. Then, the ECU 100 performs clutch engagement control (step S107). Thereby, the ECU 100 completes the transition from EV traveling to series parallel traveling. On the other hand, when the ECU 100 determines that the EV travel should not be switched to the series parallel travel (step S105; No), the process of the flowchart ends.

  On the other hand, when ECU 100 determines that vehicle speed V is equal to or lower than threshold value Vth (step S103; No), it stops engine 20 (step S108). That is, in this case, the ECU 100 stops the fuel injection of the engine 20. Then, when ECU 100 determines that switching from EV traveling to series parallel traveling is to be performed thereafter (step S109; Yes), ECU 100 determines whether engine speed Ne is equal to or higher than engine start speed Nes (step S110). On the other hand, when the ECU 100 determines that the EV travel should not be switched to the series parallel travel (step S109; No), the ECU 100 ends the process of the flowchart and continues the EV travel.

  If the ECU 100 determines in step S110 that the engine speed Ne is equal to or higher than the engine start speed Ne (step S110; Yes), the ECU 100 performs start control of the engine 20 (step S111), and then clutch synchronization. Control (step S106) and clutch engagement control (step S107) are executed. By doing in this way, ECU100 can shorten the time which engine start control requires, and can re-accelerate the hybrid vehicle 1 at an early stage according to a user's intention.

  On the other hand, when the ECU 100 determines that the engine speed Ne is less than the engine start speed Ne (step S110; No), the ECU 100 determines whether the engine speed Ne is “0” (step S112). When the ECU 100 determines that the engine speed Ne is “0” (step S112; Yes), it performs clutch synchronization control (step S113) and then performs clutch engagement control (step S114). Then, ECU 100 performs engine start control (step S115). Specifically, the ECU 100 performs fuel injection after cranking the engine 20 with the motor MG1 so as to be equal to or higher than the engine start speed Nes. On the other hand, when the ECU 100 determines that the engine speed Ne is not “0” (step S112; No), the ECU 100 waits until the engine speed Ne becomes “0”. Thus, the ECU 100 can perform the clutch synchronization control with high accuracy by adjusting the rotation speed of the engagement element RCL with the motor MG1 after the engine rotation speed Ne becomes “0”. The occurrence of a shock at the time of engagement of can be suppressed.

Second Embodiment
Next, a second embodiment will be described. Hereinafter, “engine NV speed Nenv” refers to a boundary value that defines whether the engine speed Ne is within a range where NV (noise or / and vibration) is generated. Here, ECU 100 determines that NV may occur when engine speed Ne is greater than engine NV speed Nenv.

In the second embodiment, in addition to the first embodiment, when the ECU 100 is not in the travel mode in which NV should be prioritized (also referred to as “NV priority mode”), the engine speed is changed when switching from EV travel to series parallel travel. When Ne is less than the engine start speed Nes, the engine speed Ne is greater than the engine NV speed Nenv, and the clutch differential speed dNcl is less than or equal to the threshold value dNth, the engine start control is performed after the clutch engagement control is executed. Do. That is, when the ECU 100 is not in the NV priority mode, the following relationship is established.
Nenv <Ne <Nes (1)
And the clutch differential speed dNcl is equal to or less than the threshold value dNth, clutch engagement control is performed without performing clutch synchronization control, and then engine start control is performed. Thereby, ECU100 can reduce the time which clutch synchronous control requires, can switch from EV driving | running | working at an early stage to series parallel driving | running | working, and can shorten the time to re-acceleration.

  On the other hand, in the NV priority mode, the ECU 100 executes the clutch synchronization control, the clutch engagement control, and the engine start control in this order after the engine speed Ne becomes “0”. As described above, in the NV priority mode, the ECU 100 performs clutch synchronization control after setting the engine speed Ne to “0”, thereby suppressing vibration of the engine 20 and performing clutch synchronization control with high accuracy. Can be executed. That is, the ECU 100 performs clutch synchronization control in a state where the engine speed Ne is set to “0”, so that the MG1 rotational speed that can be detected with relatively high accuracy based on the relationship of the nomograph shown in FIG. The rotational speed of the engagement element RCL can be estimated from Nmg1, and the clutch synchronization control can be executed with high accuracy.

  Further, the ECU 100 determines whether or not it is in the NV priority mode based on the operation state of a user interface such as a switch that determines whether or not the NV priority mode is installed in the vicinity of the driver's seat. Thus, the ECU 100 can appropriately execute a case where priority is given to suppression of NV and a case where priority is given to improvement of responsiveness according to the intention of the user (driver).

  In addition to the above-described method for determining whether or not the NV priority mode is used, whether or not the NV priority mode is used may be determined in advance based on the specifications of the hybrid vehicle 1.

  FIG. 4 is an example of a flowchart showing a processing procedure executed by the ECU 100 in the second embodiment. The ECU 100 repeatedly executes the processing of the flowchart shown in FIG. 4 according to a predetermined cycle when executing series parallel travel.

  First, the ECU 100 determines whether or not the travel mode should be switched from series parallel travel to EV travel (step S201). When ECU 100 determines that the travel mode should be switched from series parallel travel to EV travel (step S201; Yes), it performs clutch release control (step S202). On the other hand, when ECU 100 determines that the travel mode should not be switched from series parallel travel to EV travel (step S201; No), the process of the flowchart ends.

  Next, in step S203, the ECU 100 determines whether or not the vehicle speed V is greater than the threshold value Vth (step S203). If the ECU 100 determines that the vehicle speed V is greater than the threshold value Vth (step S203; Yes), the ECU 100 performs an idle operation of the engine 20 (step S204). And ECU100 implements clutch synchronous control (step S206), when it is judged after that that it should switch from EV driving | running | working after that to series parallel driving | running (step S205; Yes). As a result, the ECU 100 keeps the rotation speed difference between the engagement elements RCL and OCL within a predetermined rotation speed difference. Then, the ECU 100 performs clutch engagement control (step S207). Thereby, the ECU 100 completes the transition from EV traveling to series parallel traveling. On the other hand, when the ECU 100 determines that the EV travel should not be switched to the series parallel travel (step S205; No), the process of the flowchart ends.

  On the other hand, when ECU 100 determines that vehicle speed V is equal to or lower than threshold value Vth (step S203; No), it stops engine 20 (step S208). That is, in this case, the ECU 100 stops the fuel injection of the engine 20. Then, when ECU 100 determines that switching from EV traveling to series parallel traveling is to be performed thereafter (step S209; Yes), ECU 100 determines whether engine rotational speed Ne is equal to or higher than engine starting rotational speed Ne (step S210). On the other hand, when the ECU 100 determines that the EV travel should not be switched to the series parallel travel (step S209; No), the ECU 100 ends the process of the flowchart and continues the EV travel.

  If the ECU 100 determines in step S210 that the engine speed Ne is greater than or equal to the engine start speed Ne (step S210; Yes), the ECU 100 performs engine start control (step S211), and then clutch synchronization control (step S211). Step S206) and clutch engagement control (step S207) are executed. By doing in this way, ECU100 can shorten the time which engine start control requires, and can shorten the time to acceleration.

  On the other hand, when the ECU 100 determines that the engine speed Ne is less than the engine start speed Ne (step S210; No), the ECU 100 determines whether the engine speed Ne is greater than “0” (step S212). If the ECU 100 determines that the engine speed Ne is greater than “0” (step S212; Yes), the ECU 100 determines whether the engine speed Ne is greater than the engine NV speed Nenv (step S213). If the ECU 100 determines that the engine rotational speed Ne is greater than the engine NV rotational speed Neenv (step S213; Yes), the ECU 100 performs processing subsequent to step S214. On the other hand, when the engine speed Ne is equal to or lower than “0” (step S212; No), or when the engine speed Ne is equal to or lower than the engine NV speed Nenv (step S213; No), the ECU 100 performs clutch synchronization control (step S217), clutch engagement control (step S218), and engine start control (step S219) are sequentially executed.

  Next, in step S214, the ECU 100 determines whether or not the clutch differential rotation speed dNcl is equal to or less than a threshold value dNth (step S214). When the clutch differential speed dNcl is equal to or less than the threshold value dNth (step S214; Yes) and in the NV priority mode (step S215; Yes), the ECU 100 waits until the engine speed Ne becomes “0”. (Step S216). When the engine speed Ne becomes “0” (step S216; Yes), the ECU 100 performs clutch synchronization control (step S217), clutch engagement control (step S218), and engine start control (step S219). Run in order. Thereby, in the NV priority mode, the ECU 100 can switch the traveling mode while reliably suppressing the occurrence of NV.

  On the other hand, when the ECU 100 determines in step S214 that the clutch differential rotation speed dNcl is larger than the threshold value dNth (step S214; No), the ECU 100 waits until the engine rotation speed Ne becomes “0” (step S216; Yes). Then, clutch synchronization control or the like is executed (steps S217 to S219).

  Similarly, when ECU 100 determines in step S215 that the mode is not the NV priority mode (step S215; No), it performs clutch engagement control (step S218) and executes engine start control (step S219). As described above, when the ECU 100 is not in the NV priority mode, the time for performing the clutch synchronization control is reduced by performing the clutch engagement control without waiting until the engine speed Ne becomes “0”. And responsiveness can be improved.

<Third Embodiment>
Next, in the third embodiment, in addition to the second embodiment, when the ECU 100 switches from EV traveling to series parallel traveling, the engine 100 is basically operated except for the case defined in the first embodiment and the second embodiment. After the rotational speed Ne is set to “0”, the clutch synchronization control, the clutch engagement control, and the engine start control are executed in this order. Specifically, when the engine speed Ne is equal to or lower than the engine NV speed Nenv, the ECU 100 sets the engine speed Ne to “0” and then performs clutch synchronization control, clutch engagement control, and engine start control in this order. Execute. Thereby, the ECU 100 executes the clutch synchronization control with high accuracy while suppressing the vibration of the engine 20.

  This will be supplementarily described with reference to FIG. FIG. 5 is an operation alignment chart illustrating one operation state of the hybrid drive device 10 during clutch synchronous engagement control. In FIG. 5, the vertical axis represents the rotational speed, and the horizontal axis, in order from the left, the sun gear S1 (uniquely, the motor MG1), the carrier C1 (uniquely, the engine 20), the engagement element RCL (uniquely). In particular, it represents the ring gear R1), the pinion gear P1, the engagement element OCL (uniquely, the drive shaft OUT), and the motor MG2. Further, the arrow “Y1” in FIG. 5 corresponds to the power running torque by the motor MG1, the arrow “Y2” corresponds to the torque transmitted to the engine 20 by the motor MG1, and the arrow “Y3” indicates the engagement element RCL. This corresponds to the friction torque generated between OCL and OCL.

  In FIG. 5, the ECU 100 applies the MG1 torque Tmg1 in the direction of the arrow Y1, thereby increasing the rotation speed of the engagement element RCL and synchronizing it with the rotation speed of the engagement element OCL. Along with this, the friction torque generated by the MG1 torque Tmg1 and the clutch CL becomes a load on the engine 20, and torque in the negative rotation direction acts on the engine 20 (see arrow Y2). Therefore, when the clutch synchronization control is performed before the engine speed Ne becomes “0”, the engine 20 rotates in the reverse direction in the traveling state where the MG1 torque Tmg1 acts on the engine 20 in the negative rotation direction.

  Considering the above, as a general rule, the ECU 100 executes clutch synchronization control after setting the engine speed Ne to “0”. In the clutch synchronization control, the ECU 100 can specify the rotational speed of the engagement element RCL from the MG1 rotational speed Nmg1 that can be detected with relatively high accuracy, and the engine rotational speed Ne is determined based on the rotational resistance of the engine 20. Using the operating point of the engine 20 in the case of “0” as a fulcrum, the rotational speed of the engagement element RCL is adjusted by the MG1 torque Tmg1. Thereby, the ECU 100 can execute the clutch synchronization control with high accuracy, and can suppress the occurrence of a shock when the clutch CL is engaged, and can prevent the reverse rotation of the engine 20.

  FIG. 6 is an example of a flowchart showing a processing procedure executed by the ECU 100 in the third embodiment. The ECU 100 repeatedly executes the processing of the flowchart shown in FIG. 6 according to a predetermined cycle when executing series parallel travel.

  First, the ECU 100 determines whether or not the travel mode should be switched from series parallel travel to EV travel (step S301). When ECU 100 determines that the travel mode should be switched from series parallel travel to EV travel (step S301; Yes), it performs clutch release control (step S302). On the other hand, when ECU 100 determines that the travel mode should not be switched from the series parallel travel to the EV travel (step S301; No), the process of the flowchart ends.

  Next, in step S303, the ECU 100 determines whether or not the vehicle speed V is greater than the threshold value Vth (step S303). When ECU 100 determines that vehicle speed V is greater than threshold value Vth (step S303; Yes), it performs idle operation of engine 20 (step S304). Then, when ECU 100 determines that switching from EV traveling to series parallel traveling is to be performed thereafter (step S305; Yes), it performs clutch synchronization control (step S306), and then performs clutch engagement control (step S307). . On the other hand, when the ECU 100 determines that the EV travel should not be switched to the series parallel travel (step S305; No), the process of the flowchart ends.

  On the other hand, when ECU 100 determines that vehicle speed V is equal to or lower than threshold value Vth (step S303; No), it stops engine 20 (step S308). That is, in this case, the ECU 100 stops the fuel injection of the engine 20. Then, when ECU 100 determines that the EV travel should be switched to the series parallel travel (step S309; Yes), it determines whether engine speed Ne is equal to or higher than engine start speed Nes (step S310). On the other hand, when the ECU 100 determines that the EV travel should not be switched to the series parallel travel (step S309; No), the ECU 100 ends the process of the flowchart and continues the EV travel.

  When the ECU 100 determines in step S310 that the engine speed Ne is equal to or higher than the engine start speed Ne (step S310; Yes), the ECU 100 starts the engine 20 (step S311), and then performs clutch synchronization control. (Step S306) and clutch engagement control (Step S307) are executed. By doing in this way, ECU100 can shorten the time which engine start control requires, shorten the time to acceleration, and can improve responsiveness.

  On the other hand, when the ECU 100 determines that the engine speed Ne is less than the engine start speed Ne (step S310; No), the ECU 100 determines whether the engine speed Ne is greater than “0” (step S312). If the ECU 100 determines that the engine speed Ne is greater than “0” (step S312; Yes), the ECU 100 determines whether the engine speed Ne is greater than the engine NV speed Nenv (step S313). If the ECU 100 determines that the engine rotational speed Ne is greater than the engine NV rotational speed Neenv (step S313; Yes), the ECU 100 performs processing from step S314 onward.

  On the other hand, when the engine speed Ne is “0” or less (step S312; No), the ECU 100 performs clutch synchronization control (step S317), clutch engagement control (step S318), and engine start control (step S312). S319) is executed in order.

  In step S313, when the engine speed Ne is equal to or lower than the engine NV speed Nenv (step S313; No), the ECU 100 waits until the engine speed Ne becomes “0” (step S316), and then the clutch. Synchronization control (step S317), clutch engagement control (step S318), and engine start control (step S319) are sequentially executed. Thus, ECU 100 can suppress vibration of engine 20 and perform clutch synchronization control with high accuracy to suppress the occurrence of shock when clutch CL is engaged. Further, the ECU 100 can prevent reverse rotation of the engine 20.

  Next, in step S314, the ECU 100 determines whether or not the clutch differential rotation speed dNcl is equal to or less than a threshold value dNth (step S314). When the clutch differential speed dNcl is equal to or less than the threshold value dNth (step S314; Yes) and in the NV priority mode (step S315; Yes), the ECU 100 waits until the engine speed Ne becomes “0”. (Step S316). When the engine speed Ne becomes “0” (step S316; Yes), the ECU 100 performs clutch synchronization control (step S317), clutch engagement control (step S318), and engine start control (step S319). Run in order. Thereby, in the NV priority mode, the ECU 100 can switch the traveling mode while reliably suppressing the occurrence of NV.

  On the other hand, if the ECU 100 determines in step S314 that the clutch differential rotation speed dNcl is larger than the threshold value dNth (step S314; No), the ECU 100 waits until the engine rotation speed Ne becomes “0” (step S316; Yes). Then, clutch synchronization control or the like is executed (steps S317 to S319).

In step S315, when ECU 100 determines that it is not the NV priority mode (step S315; No), it performs clutch engagement control (step S318) and executes engine start control (step S319). Thereby, ECU100 can reduce the time which performs clutch synchronous control, and can start engine 20 at an early stage.
[Modification]
Next, modified examples suitable for each embodiment will be described. The following modifications may be applied to each embodiment in any combination.

(Modification 1)
In the flowchart of FIG. 4, the ECU 100 determines whether the engine is in the NV priority mode (see step S215), the engine speed Ne (see steps S210, S212, and S213), the engine start speed Ne (see step S210), and the engine NV. Based on the rotational speed Nenv (see step S213) and the clutch differential rotational speed dNcl (see step S214), should the control (see step S216) be performed to set the engine rotational speed Ne to “0” before clutch synchronization control? Decided or not. However, the method to which the present invention is applicable is not limited to this.

  Instead of this, the ECU 100 may determine whether or not the engine speed Ne should be set to “0” based only on whether or not the NV priority mode is set. Specifically, in this case, in the NV priority mode, the ECU 100 sets the engine speed Ne to “0”, and then executes clutch synchronization control and the like (see steps S217 to S219). If not, clutch synchronization control or the like is executed without setting the engine speed Ne to “0”. As a result, the ECU 100 can suppress NV when the clutch CL is engaged in the NV priority mode, and when not in the NV priority mode, the ECU 100 engages the clutch CL at an early stage to improve responsiveness. Can be improved.

(Modification 2)
In step S112, step S216, and step S316 in FIG. 3, the ECU 100 waits without performing clutch synchronization control until the engine speed Ne becomes “0”. However, the method to which the present invention is applicable is not limited to this. Instead, the ECU 100 may start the clutch synchronization control when the engine speed Ne is substantially 0, that is, within a predetermined range including “0”. The predetermined range is a range of the engine speed Ne at which the clutch synchronization control can be performed with high accuracy, as in the case where the engine speed Ne is “0”, and is determined in advance based on, for example, experiments. Also by this, the ECU 100 can preferably suppress the vibration of the engine 20 and suppress the occurrence of a shock when the clutch CL is engaged.

(Modification 3)
In the second embodiment, the ECU 100 performs clutch engagement control without performing clutch synchronization control when the formula (1) is satisfied and the clutch differential rotation speed dNcl is equal to or less than the threshold value dNth when not in the NV priority mode. Then, engine start control was performed. However, the configuration to which the present invention is applicable is not limited to this. Instead, when not in the NV priority mode, the ECU 100 may perform the clutch engagement control without performing the clutch synchronization control if the clutch differential rotation speed dNcl is equal to or less than the threshold value dNth. Also by this, the ECU 100 can suitably switch from EV traveling to series parallel traveling at an early stage, and can improve responsiveness to reacceleration and the like.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 10 Hybrid drive device 12 Battery 20 Engine 30 Power split mechanism 40 Input shaft 60 Deceleration mechanism 100 ECU
MG1, MG2 Motor generator CL Clutch

Claims (3)

Engine,
A first rotating electrical machine;
A second rotating electrical machine;
A first rotating element connected to the first rotating electric machine, a second rotating element connected to the second rotating electric machine and a drive shaft via a clutch, and a third rotating element connected to the engine. A power transmission mechanism having a plurality of rotating elements capable of differential rotation with each other;
From the first traveling mode in which the clutch is disengaged and the engine is stopped and traveling by the second rotating electrical machine is changed to the second traveling mode in which the clutch is engaged and the engine is driven to travel. A control means for starting the engine after engaging the clutch when switching the running mode;
In a state where noise or / and vibration suppression should be prioritized, the control means sets the engine speed to approximately 0, then engages the clutch, and starts the engine. Control device.   The hybrid vehicle control device according to claim 1, further comprising an interface for allowing a user to designate whether noise or / and vibration suppression should be prioritized.   The control means is configured to rotate the engagement element of the clutch when the differential rotation speed of the engagement element of the clutch is not more than a predetermined value and the suppression of noise or / and vibration is not a priority. The control apparatus for a hybrid vehicle according to claim 1 or 2, wherein the clutch is engaged without performing synchronization control.

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