JP2008168810A - Powertrain control device, control method, program for realizing the method, and recording medium recording the program - Google Patents

Abstract

To prevent an engine from stalling or reversing.
When the N range is selected (YES in S100), the ECU increases or decreases the rotational speed of the first MG connected to the sun gear of the power split mechanism to reduce the rotational speed NR of the ring gear to the target rotational speed NR. In step (S102) for executing the synchronization control to (T) and when the engine connected to the carrier is stopped (YES in S104), the engine speed NE is equal to or less than a threshold value A which is a negative value. (YES in S112), the step of prohibiting the synchronous control (S114), and the engine speed NE is equal to or less than a threshold value B which is a positive value during the engine independent operation (YES in S120). (YES in S132) and a program including the step of prohibiting synchronous control (S134) is executed.
[Selection] Figure 6

Description

  The present invention relates to a power train control device, a control method, a program for realizing the method, and a recording medium on which the program is recorded. In particular, the rotational speed of a rotating element connected to a rotating electrical machine is a target rotational speed. It relates to the technology to control.

  Conventionally, a hybrid vehicle having an engine and a rotating electric machine as drive sources is known. In such a hybrid vehicle, an engine and a rotating electric machine are selectively used according to the traveling state of the vehicle. For example, the vehicle travels mainly using an engine when traveling at a high speed, and travels mainly using a rotating electrical machine when traveling at a medium or low speed. One of such hybrid vehicles includes a differential mechanism that functions as a continuously variable transmission using a rotating electric machine.

  Japanese Patent Laying-Open No. 2005-337491 (Patent Document 1) includes a first element coupled to an engine, a second element coupled to a first electric motor (rotating electric machine), and a third element coupled to a second electric motor. Control of a vehicle drive device comprising a continuously variable transmission having a configured differential mechanism and functioning as an electric continuously variable transmission, and a transmission provided between the continuously variable transmission and the wheels An apparatus is disclosed. In the control device described in Patent Document 1, the gear of the continuously variable transmission unit is synchronized with the shift so that the gear ratio formed by the continuously variable transmission unit and the transmission unit is continuous when the transmission unit shifts. Including a continuously variable transmission control unit.

According to the control device described in this publication, the gear ratio formed by the continuously variable transmission unit and the transmission unit, that is, the gear ratio formed based on the transmission ratio of the continuously variable transmission unit and the transmission gear ratio. The overall gear ratio is continuously changed. As a result, the engine speed (the number of revolutions) is continuously changed before and after the speed change of the speed change unit to reduce the speed change shock.
JP 2005-337491 A

  When a transmission unit different from the continuously variable transmission unit is provided between the wheel and the continuously variable transmission unit as in the vehicle drive device described in Japanese Patent Laid-Open No. 2005-337491, the transmission unit is in a neutral state. The output shaft speed of the continuously variable transmission can take any value that is not limited by the vehicle speed. However, when the transmission unit is not in the neutral state while the vehicle is running, a shock may occur if the output shaft speed of the continuously variable transmission unit is excessive or insufficient with respect to the vehicle speed. Therefore, it is preferable to synchronize the output shaft rotational speed of the continuously variable transmission unit with the synchronous rotational speed calculated from the output shaft rotational speed of the transmission unit different from the continuously variable transmission unit. However, when the rotating electrical machine is operated to control the output shaft rotation speed of the continuously variable transmission, torque acts on the engine via the differential mechanism. This torque can reduce the engine speed. As a result, the engine can stall or reverse. However, Japanese Patent Laid-Open No. 2005-337491 does not describe anything about such a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power train control device, control method, and method that can prevent the engine from stalling or reversing. It is to provide a program to be realized and a recording medium on which the program is recorded.

  According to a first aspect of the present invention, there is provided a power train control device comprising: a first rotating element coupled to a first rotating electrical machine; a second rotating element coupled to a second rotating electrical machine; and a third coupled to an engine. A differential mechanism having a plurality of rotating elements, a first state that is coupled to the second rotating element, and that transmits torque input from the second rotating element to the wheel, and torque from the second rotating element to the wheel. A power train control device including a switching mechanism capable of switching between a second state in which transmission is interrupted. In the second state, the controller controls at least one of the first rotating electric machine and the second rotating electric machine so that the rotation speed of the second rotating element becomes the target rotation speed. Means for executing the synchronous control to be controlled, and prohibiting means for prohibiting the synchronous control when the engine speed falls below a predetermined value during the execution of the synchronous control. The power train control method according to the fourth aspect of the present invention has the same configuration as the power train control device according to the first aspect of the present invention.

  According to the first or fourth invention, the power train is connected to the first rotating element connected to the first rotating electric machine, the second rotating element connected to the second rotating electric machine, and the first rotating element connected to the engine. A differential mechanism having three rotating elements, a first state connected to the second rotating element, and transmitting torque input from the second rotating element to the wheel, and torque from the second rotating element to the wheel And a switching mechanism capable of switching between the second state in which the transmission is interrupted. In the second state, synchronous control for controlling at least one of the first rotating electrical machine and the second rotating electrical machine is performed so that the rotational speed of the second rotating element becomes the target rotational speed. Executed. At this time, torque acts on the engine via the differential mechanism. This torque can reduce the engine speed. Therefore, when the engine speed is equal to or lower than a predetermined value during execution of the synchronization control, the synchronization control is prohibited. Thereby, the fall of an engine speed can be restrict | limited. Therefore, it is possible to provide a power train control device or control method capable of preventing the engine from stalling or reversing.

  In the power train control device according to the second invention, in addition to the configuration of the first invention, the prohibiting means performs synchronous control when the engine speed is less than a predetermined positive value during engine operation. Includes means for prohibition. The power train control method according to the fifth aspect of the present invention has the same configuration as the power train control apparatus according to the second aspect of the present invention.

  According to the second or fifth invention, the synchronous control is prohibited when the engine speed becomes equal to or less than a predetermined positive value during engine operation. This can prevent the engine from stalling.

  In the power train control device according to the third invention, in addition to the configuration of the first invention, the prohibiting means performs synchronous control when the engine speed is equal to or less than a predetermined negative value when the engine is stopped. Includes means for prohibition. A power train control method according to a sixth aspect of the present invention has the same configuration as the power train control apparatus according to the third aspect of the present invention.

  According to the third or sixth aspect, the synchronous control is prohibited when the engine speed becomes equal to or less than a predetermined negative value when the engine is stopped. Thereby, it is possible to prevent the engine from reversing.

  A program according to a seventh aspect is a program for causing a computer to implement the control method according to any of the fourth to sixth aspects, and a recording medium according to the eighth aspect is any one of the fourth to sixth aspects. It is a computer-readable recording medium which recorded the program which makes a computer implement | achieve this control method.

  A program according to a seventh aspect is a program for causing a computer to implement the control method according to any of the fourth to sixth aspects, and a recording medium according to the eighth aspect is any one of the fourth to sixth aspects. It is a computer-readable recording medium which recorded the program which makes a computer implement | achieve this control method.

  According to the seventh or eighth invention, the power train control method according to any of the fourth to sixth inventions can be realized using a computer (which may be general purpose or dedicated).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A hybrid vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This hybrid vehicle is an FR (Front engine Rear drive) vehicle. A vehicle other than FR may be used.

  The hybrid vehicle includes a hybrid system 100 as a drive source, an automatic transmission 400, a propeller shaft 500, a differential gear 600, a rear wheel 700, and an ECU (Electronic Control Unit) 800. The control device according to the present embodiment is realized, for example, by executing a program recorded in ROM (Read Only Memory) 802 of ECU 800. The hybrid vehicle power train includes a hybrid system 100 and an automatic transmission 400.

  The engine 200 of the hybrid system 100 is an internal combustion engine that burns a mixture of fuel and air injected from an injector 202 in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 400 is coupled to the output shaft of hybrid system 100. The driving force output from the automatic transmission 400 is transmitted to the left and right rear wheels 700 via the propeller shaft 500 and the differential gear 600.

  The ECU 800 includes a position switch 806 for the shift lever 804, an accelerator opening sensor 810 for the accelerator pedal 808, a depression force sensor 814 for the brake pedal 812, a throttle opening sensor 818 for the electronic throttle valve 816, and an engine speed sensor 820. The input shaft speed sensor 822, the output shaft speed sensor 824, the oil temperature sensor 826, and the water temperature sensor 828 are connected via a harness or the like.

  The position (position) of shift lever 804 is detected by position switch 806, and a signal representing the detection result is transmitted to ECU 800. Corresponding to the position of the shift lever 804, a shift in the automatic transmission 400 is automatically performed.

  Accelerator opening sensor 810 detects the opening of accelerator pedal 808 and transmits a signal representing the detection result to ECU 800. The pedaling force sensor 814 detects the pedaling force of the brake pedal 812 (the force with which the driver steps on the brake pedal 812), and transmits a signal representing the detection result to the ECU 800.

  The throttle opening sensor 818 detects the opening of the electronic throttle valve 816 whose opening is adjusted by the actuator, and transmits a signal indicating the detection result to the ECU 800. The electronic throttle valve 816 adjusts the amount of air taken into the engine 200 (output of the engine 200).

  Instead of or in addition to the electronic throttle valve 816, the amount of air sucked into the engine 200 is changed by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  Engine rotation speed sensor 820 detects the rotation speed (engine rotation speed NE) of the output shaft (crankshaft) of engine 200 and transmits a signal representing the detection result to ECU 800. Input shaft speed sensor 822 detects input shaft speed NI of automatic transmission 400 and transmits a signal representing the detection result to ECU 800. Output shaft rotational speed sensor 824 detects output shaft rotational speed NO of automatic transmission 400 and transmits a signal representing the detection result to ECU 800.

  The travel distance of the hybrid vehicle is calculated from the output shaft rotational speed NO of the automatic transmission 400. The calculated travel distance is stored in the memory of ECU 800. In addition, about the method of calculating a travel distance, since it should just use a known general technique, the detailed description is not repeated here.

  Oil temperature sensor 826 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 400 and transmits a signal representing the detection result to ECU 800.

  Water temperature sensor 828 detects the temperature (water temperature) of cooling water for engine 200 and transmits a signal representing the detection result to ECU 800.

  The ECU 800 includes a position switch 806, an accelerator opening sensor 810, a pedaling force sensor 814, a throttle opening sensor 818, an engine speed sensor 820, an input shaft speed sensor 822, an output shaft speed sensor 824, an oil temperature sensor 826, and a water temperature sensor. Based on the signal sent from 828 or the like, the map stored in the ROM 802 and the program, the devices are controlled so that the vehicle is in a desired running state.

  The hybrid system 100 and the automatic transmission 400 will be further described with reference to FIG.

  Hybrid system 100 includes an engine 200, a power split mechanism 310, a first MG (Motor Generator) 311, and a second MG 312. Power split device 310 splits the output of engine 200 input to input shaft 302 into first MG 311 and output shaft 304. Power split device 310 includes planetary gear 320.

  Planetary gear 320 includes a sun gear 322, a pinion gear 324, a carrier 326 that supports the pinion gear 324 so as to rotate and revolve, and a ring gear 328 that meshes with the sun gear 322 via the pinion gear 324.

  In power split device 310, carrier 326 is connected to input shaft 302, that is, engine 200. Sun gear 322 is connected to first MG 311. Ring gear 328 is coupled to output shaft 304.

  Power split device 310 functions as a differential device by relatively rotating sun gear 322, carrier 326, and ring gear 328. Due to the differential function of power split device 310, the output of engine 200 is distributed to first MG 311 and output shaft 304.

  The first MG 311 generates electric power using a part of the output of the distributed engine 200, or the second MG 312 is rotationally driven using electric power generated by the first MG 311 so that the power split mechanism 310 is a continuously variable transmission. Function as.

  First MG 311 and second MG 312 are three-phase AC rotating electric machines. First MG 311 is coupled to sun gear 322 of power split device 310. Second MG 312 is provided such that the rotor rotates integrally with output shaft 304.

  First MG 311 and second MG 312 are controlled so as to satisfy the target output torque of automatic transmission 400 calculated from, for example, the accelerator opening and the vehicle speed, and to realize optimum fuel consumption in engine 200.

  The automatic transmission 400 includes an input shaft 404 as an input rotating member and an output shaft 406 as an output rotating member disposed on a common axis in a case 402 as a non-rotating member attached to the vehicle body.

  Input shaft 404 is connected to output shaft 304 of power split device 310. Therefore, the input shaft rotational speed NI of automatic transmission 400 and the output shaft rotational speed of power split device 310, that is, rotational speed NR of ring gear 328 are the same.

  The automatic transmission 400 includes a single pinion type first planetary gear (P1) 410 and a second planetary gear (P2) 420, and five frictional engagements including a C1 clutch 431, a C2 clutch 432, a C3 clutch 433, a B1 brake 441, and a B2 brake 442. And a combination element.

  Further, automatic transmission 400 includes one-way clutch (F) 450. One-way clutch (F) 450 allows relative rotation of inner race 452 and outer race 454 in one direction and restricts the reverse direction. In the present embodiment, the engaged state of the one-way clutch (F) 450 means a state where relative rotation between the inner race 452 and the outer race 454 is restricted.

  First planetary gear (P1) 410 includes a sun gear (S1) 412, a carrier (CA1) 414, and a ring gear (R1) 416. The sun gear (S1) 412 is connected to the input shaft 404 by the engagement of the C3 clutch 433. The sun gear (S1) 412 is fixed to the case 402 by the engagement of the B1 brake 441.

  The carrier (CA1) 414 is connected to the input shaft 404 by engagement of the C2 clutch 432. The carrier (CA1) 414 is fixed to the case 402 by the engagement of the B2 brake 442 or the one-way clutch (F) 450. Ring gear (R 1) 416 is coupled to output shaft 406.

  Second planetary gear (P2) 420 includes a sun gear (S2) 422, a carrier (CA2) 424, and a ring gear (R2) 426. The sun gear (S2) 422 is connected to the input shaft 404 by engagement of the C1 clutch 431.

  The carrier (CA2) 424 is coupled to the output shaft 406. Ring gear (R2) 426 is coupled to carrier (CA1) 414 of first planetary gear (P1) 410. Therefore, the ring gear (R2) 426 is fixed to the case 402 by the engagement of the B2 brake 442 or the one-way clutch (F) 450.

  A desired gear stage is formed in the automatic transmission 400 by engaging the friction engagement elements of the automatic transmission 400 in a predetermined combination.

  In the present embodiment, when the vehicle is driven (running with the driving force of the drive source), the first gear is formed by engagement of C1 clutch 431 and one-way clutch (F) 450. When the vehicle is driven, a first gear is formed by engagement of the C1 clutch 431 and the B2 brake 442.

  The engagement of the C1 clutch 431 and the B1 brake 441 forms a second gear. The engagement of the C1 clutch 431 and the C2 clutch 432 forms a third gear. Shifting in automatic transmission 400 is performed based on, for example, a shift diagram.

  In a state where the gear stage is formed in automatic transmission 400, torque (output torque of hybrid system 100) input from ring gear 328 of power split mechanism 310 to automatic transmission 400 is transmitted to rear wheel 700 that is a drive wheel.

  In the neutral state of automatic transmission 400, all the frictional engagement elements are released. In the neutral state, transmission of torque from the ring gear 328 of the power split mechanism 310 to the rear wheel 700 is interrupted.

  The C1 clutch 431, the C2 clutch 432, the C3 clutch 433, the B1 brake 441 and the B2 brake 442 are operated by hydraulic pressure. In the present embodiment, as shown in FIG. 3, the hybrid vehicle is provided with a hydraulic control device 900 that supplies / discharges hydraulic pressure to / from each friction engagement element and controls engagement / release.

  The hydraulic control apparatus 900 adjusts the hydraulic pressure generated by the mechanical oil pump 910, the electric oil pump 920, and the oil pumps 910 and 920 to the line pressure, and the hydraulic pressure adjusted using the line pressure as the original pressure. And a hydraulic circuit 930 that supplies oil for lubrication to an appropriate location.

  Mechanical oil pump 910 is a pump that is driven by engine 200 to generate hydraulic pressure. The mechanical oil pump 910 is disposed coaxially with the carrier 326 and is operated by receiving torque from the engine 200. That is, when the carrier 326 rotates, the mechanical oil pump 910 is driven, and hydraulic pressure is generated.

  On the other hand, the electric oil pump 920 is a pump driven by a motor (not shown). The electric oil pump 920 is attached to an appropriate location such as the outside of the case 402. Electric oil pump 920 is controlled by ECU 800 to generate a desired oil pressure. For example, the rotational speed of the electric oil pump 920 is feedback-controlled.

  The rotational speed of electric oil pump 920 is detected by rotational speed sensor 830, and a signal representing the detection result is transmitted to ECU 800. Further, the discharge pressure from the electric oil pump 920 is detected by the hydraulic sensor 832, and a signal indicating the detection result is transmitted to the ECU 800. The electric oil pump 920 is operated by electric power supplied from the battery 942 via the DC / DC converter 940.

  The hydraulic circuit 930 includes a plurality of solenoid valves, switching valves, or pressure regulating valves (each not shown), and is configured to be able to electrically control pressure regulation and hydraulic supply / discharge. The control is performed by the ECU 800.

  In addition, check valves 912 and 922 that open at the discharge pressure of the oil pumps 910 and 920 and close in the opposite direction are provided on the discharge side of the oil pumps 910 and 920, and the hydraulic circuit 930 includes On the other hand, these oil pumps 910 and 920 are connected in parallel to each other. In addition, a valve (not shown) that regulates the line pressure increases the discharge amount to increase the line pressure, and conversely controls the line pressure to reduce the discharge amount to lower the line pressure. Is configured to do.

  With reference to FIG. 4, the function of ECU 800 serving as the control device according to the present embodiment will be described. The functions of ECU 800 described below may be realized by hardware or may be realized by software.

  ECU 800 includes a synchronization control unit 840 and a prohibition unit 842. Synchronous control unit 840 performs synchronous control in which the rotational speed NR of ring gear 328 of power split mechanism 310 is set to target rotational speed NR (T) in a state where an N (neutral) range is selected, that is, in a neutral state of automatic transmission 400. Execute.

  Specifically, as shown in FIG. 5, the rotational speed of first MG 311 of hybrid system 100, that is, the rotational speed NS of sun gear 322, is increased or decreased, and the rotational speed NR of ring gear 328 of power split mechanism 310 becomes the target rotational speed NR. Synchronization control is executed so that (T). By increasing or decreasing the rotational speed NS of the sun gear 322 using the engine rotational speed NE as a fulcrum, the rotational speed NR of the ring gear 328 is increased or decreased.

  For example, when sensors such as the input shaft speed sensor 822 and the output shaft speed sensor 824 are operating normally, the gear ratio of the gear stage expected to be formed in the automatic transmission 400 and the output shaft speed The product with NO is set to the target rotational speed NR (T).

  When sensors such as the input shaft rotational speed sensor 822 and the output shaft rotational speed sensor 824 are failing or in the dead zone, “0” is set as the target rotational speed NR (T). Note that the method of setting the target rotational speed NR (T) is not limited to this.

  Synchronous control of the rotational speed NR of the ring gear 328 is executed as feedback control using the following equation (1). Proportional control, integral control, and differential control are used for feedback control.

  Note that “FB (R)” in Equation (1) is a feedback correction amount. “ΔNR (P)” is a difference (NR (T) −NR) between the target rotational speed NR (T) and the rotational speed NR of the ring gear 328. “ΔNR (I)” is an integral value of the difference between the target rotational speed NR (T) and the rotational speed NR of the ring gear 328. “NR (D)” is a differential value of the rotational speed NR of the ring gear 328. “X” is the feedback gain of the proportional term. “Y” is the feedback gain of the integral term. “X” is a feedback gain of the differential term.

FB (R) = X × ΔNR (P) + Y × ΔNR (I) + Z × NR (D) (1)
The feedback gains “X”, “Y”, and “Z” are determined in advance by experiments or the like. Note that synchronous control of the rotational speed NR of the ring gear 328 may be performed using at least one of proportional control, integral control, and differential control. Further, the second MG 312 may be used to perform synchronous control of the rotational speed NR of the ring gear 328.

  The prohibiting unit 842 prohibits the synchronization control when the engine speed NE is equal to or less than a negative threshold A when the engine 100 is stopped during the execution of the synchronization control. In addition, prohibition unit 842 prohibits synchronous control when engine speed NE is equal to or less than a positive threshold value B during operation of engine 100 during execution of synchronous control.

  With reference to FIG. 6, a control structure of a program executed by ECU 800 serving as the control apparatus according to the present embodiment will be described. The program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as S) 100, ECU 800 determines whether or not N range is selected. For example, when the shift lever 804 is in the N position, it is determined that the N range is selected. If the N range is selected (YES in S100), the process proceeds to S102. Otherwise (NO in S100), this process ends. In S102, ECU 800 executes synchronous control of rotation speed NR of ring gear 328.

  In S104, ECU 800 determines whether engine 100 is stopped or not. Since whether or not to stop engine 100 is determined by ECU 800 itself, whether or not engine 100 is stopped is determined inside ECU 800. If engine 100 is stopped (YES in S104), the process proceeds to S110. If not (NO in S104), the process proceeds to S120.

  In S110, ECU 800 detects engine speed NE based on the signal transmitted from engine speed sensor 820. In S112, ECU 800 determines whether engine speed NE is equal to or lower than threshold value A or not. If engine speed NE is equal to or lower than threshold value A (YES in S112), the process proceeds to S114. Otherwise (NO in S112), this process ends. In S114, ECU 800 prohibits synchronous control of rotation speed NR of ring gear 328.

  In S120, ECU 800 determines whether engine 200 is in an autonomous operation (idling) or not. If engine 200 is operating independently (YES in S120), the process proceeds to S130. Otherwise (NO in S120), this process ends.

  In S130, ECU 800 detects engine speed NE based on the signal transmitted from engine speed sensor 820. In S132, ECU 800 determines whether engine speed NE is equal to or lower than threshold value B or not. If engine speed NE is equal to or lower than threshold value B (YES in S132), the process proceeds to S134. Otherwise (NO in S132), this process ends. In S134, ECU 800 prohibits synchronous control of rotation speed NR of ring gear 328.

  An operation of ECU 800 serving as the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  When the N range is selected (YES in S100), synchronous control of the rotational speed NR of the ring gear 328 is executed in preparation for the D (drive) range or the R (reverse) range (S102). For example, when the D range is expected after the N range, the product of the gear ratio of the gear stage and the output shaft rotational speed NO is set as the target rotational speed NR (T).

  Therefore, when the vehicle is moving backward in a state where the N range is selected, the target rotational speed NR (T) is set to a negative value and the rotational speed NR of the ring gear 328 is set as shown by the broken line in FIG. May be negative.

  In such a case, if the hybrid vehicle suddenly brakes, the target rotational speed NR (T) may increase rapidly. In order to make the target rotational speed NR (T) follow the rotational speed NR of the ring gear 328, as shown by the solid line in FIG. 7, when the rotational speed of the first MG 311 (the rotational speed of the sun gear 322) suddenly decreases, the engine 100 The torque acts in the direction of decreasing the engine speed NE, and the engine speed NE is decreased.

  Further, when the sensors such as the input shaft rotational speed sensor 822 and the output shaft rotational speed sensor 824 are failing or in the dead band, as shown by a solid line in FIG. Is set to the target rotational speed NR (T).

  In such a state, it is assumed that the R range, the N range, and the D range are selected in this order, for example. In the R range, as indicated by the alternate long and short dash line in FIG. 8, the rotational speed NR of the ring gear 328 becomes a positive value, and the hybrid vehicle moves backward.

  In the N range, as indicated by a solid line in FIG. 8, the rotational speed NR of the ring gear 328 becomes “0” by synchronous control.

  When the D range is selected after the hybrid vehicle moves backward and before stopping, the friction engagement element of the automatic transmission 400 starts to have a torque capacity, as shown by a two-dot chain line in FIG. It may be lowered until NR becomes a negative value.

  Thereafter, when the N range is selected again, the rotational speed of the first MG 311 is decreased in order to set the rotational speed of the rotational speed NR of the ring gear 328 to “0”. However, if the torque capacity remains in the friction engagement element of automatic transmission 400, the rotational speed NR of ring gear 328 cannot actually increase to “0” as shown by the solid line in FIG. Therefore, torque acts on engine 100 in the direction of decreasing engine speed NE, and engine speed NE is decreased.

  Therefore, in the present embodiment, when the engine speed NE decreases during the synchronous control, the synchronous control is prohibited.

  If engine 100 is stopped (YES in S104), engine speed NE is detected (S110). If engine speed NE is equal to or less than negative threshold value A (YES in S112), synchronous control of rotation speed NR of ring gear 328 is prohibited (S114). Thereby, engine 100 can be prevented from rotating in reverse. Therefore, for example, the mechanical oil pump 910 driven by the engine 100 can be prevented from sucking out oil from the hydraulic circuit 930.

  If engine 200 is operating independently (YES in S120), engine speed NE is detected (S130). If engine speed NE is equal to or less than negative threshold value B (YES in S132), synchronous control of rotation speed NR of ring gear 328 is prohibited (S134). Thereby, the engine 100 can be prevented from stalling.

  As described above, according to the ECU that is the control apparatus according to the present embodiment, the rotational speed NR of the ring gear of the power split mechanism becomes the target rotational speed NR (T) by increasing or decreasing the rotational speed of the first MG. Synchronous control is executed. During the execution of the synchronous control, the synchronous control is prohibited when the engine speed NE becomes equal to or less than a negative threshold value A when the engine is stopped. In addition, during the execution of the synchronization control, if the engine speed NE is equal to or less than a positive threshold value B during engine operation, the synchronization control is prohibited. Thereby, it is possible to prevent the engine from rotating backward or stalling.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram which shows the hybrid vehicle carrying ECU which is a control apparatus which concerns on embodiment of this invention. It is a figure which shows a hybrid system and an automatic transmission. It is a figure which shows a hydraulic control apparatus. It is a functional block diagram of ECU which is a control device concerning an embodiment of the invention. It is a figure (the 1) which shows the alignment chart of a power split device. It is a flowchart which shows the control structure of the program which ECU which is a control apparatus which concerns on embodiment of this invention performs. FIG. 8 is a second diagram showing a nomographic chart of the power split mechanism. FIG. 9 is a third diagram illustrating a nomographic chart of the power split mechanism. FIG. 6 is a diagram (No. 4) illustrating an alignment chart of a power split mechanism;

Explanation of symbols

  100 hybrid system, 200 engine, 310 power split mechanism, 311 1st MG, 312 2nd MG, 320 planetary gear, 322 sun gear, 324 pinion gear, 326 carrier, 328 ring gear, 400 automatic transmission, 404 input shaft, 406 output shaft, 431 C1 clutch 432 C2 clutch, 433 C3 clutch, 441 B1 brake, 442 B2 brake, 450 one-way clutch (F), 800 ECU, 802 ROM, 804 shift lever, 806 position switch, 808 accelerator pedal, 810 accelerator opening sensor, 812 brake Pedal, 814 pedal force sensor, 816 electronic throttle valve, 818 throttle opening sensor, 820 engine speed Capacitors, 822 the input shaft rotational speed sensor, 824 an output shaft rotational speed sensor, 826 an oil temperature sensor, 828 temperature sensor, 830 rpm sensor, 832 a hydraulic sensor, 840 synchronization control unit, 842 prohibition unit.

Claims (8)

A differential mechanism having a first rotating element coupled to the first rotating electrical machine, a second rotating element coupled to the second rotating electrical machine, and a third rotating element coupled to the engine; A first state in which torque input from the second rotating element is transmitted to the wheel and a second state in which transmission of torque from the second rotating element to the wheel is interrupted. A power train control device comprising a switching mechanism capable of switching between,
In the second state, at least one of the first rotating electrical machine and the second rotating electrical machine is controlled so that the rotational speed of the second rotating element becomes a target rotational speed. Means for executing synchronous control;
A control apparatus for a power train, comprising: prohibiting means for prohibiting the synchronization control when the engine speed becomes a predetermined value or less during execution of the synchronization control.   2. The power train control device according to claim 1, wherein the prohibiting unit includes a unit for prohibiting the synchronization control when the engine speed is equal to or lower than a predetermined positive value during operation of the engine. .   2. The power train control device according to claim 1, wherein the prohibiting unit includes a unit for prohibiting the synchronization control when the engine speed is equal to or lower than a predetermined negative value when the engine is stopped. 3. . A differential mechanism having a first rotating element coupled to the first rotating electrical machine, a second rotating element coupled to the second rotating electrical machine, and a third rotating element coupled to the engine; A first state in which torque input from the second rotating element is transmitted to the wheel and a second state in which transmission of torque from the second rotating element to the wheel is interrupted. A power train control method comprising a switching mechanism capable of switching between,
In the second state, at least one of the first rotating electrical machine and the second rotating electrical machine is controlled so that the rotational speed of the second rotating element becomes a target rotational speed. Executing synchronous control to perform,
During the execution of the synchronization control, the method for controlling the power train includes a step of prohibiting the synchronization control when the engine speed becomes a predetermined value or less.   5. The power train according to claim 4, wherein the step of prohibiting the synchronization control includes a step of prohibiting the synchronization control when the rotational speed of the engine becomes a predetermined positive value or less during operation of the engine. Control method.   5. The power train according to claim 4, wherein the step of prohibiting the synchronization control includes the step of prohibiting the synchronization control when the engine speed becomes equal to or less than a predetermined negative value when the engine is stopped. Control method.   The program which makes a computer implement | achieve the control method in any one of Claims 4-6.   A computer-readable recording medium recording a program for causing a computer to implement the control method according to claim 4.

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