JP5332756B2 - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a hybrid vehicle which appropriately executes a failure determination operation for a lock mechanism. <P>SOLUTION: The control device of the hybrid vehicle includes an engagement mechanism configured to fix the rotation of a first motor generator, and is applied to the hybrid vehicle for switching between a continuously variable transmission mode and a fixed transmission mode by using the engagement element. A failure determination means determines whether the engagement mechanism has failed or not when the hybrid vehicle is not traveling. In this structure, the failure of the engagement element is appropriately determined without causing a sense of incongruity to a driver during traveling. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

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

  Hybrid vehicles that include a power source such as a generator (first motor generator) and an electric motor (second motor generator) in addition to the engine are known. In a hybrid vehicle, the engine is operated in a highly efficient state as much as possible, while excess or deficiency of driving force or engine braking force is compensated by the first motor generator or the second motor generator.

  For example, Patent Document 1 proposes a hybrid vehicle including a lock mechanism (brake) that fixes rotation of a first motor generator. In this technique, the rotation of the first motor generator is fixed by a lock mechanism, and the engine is started.

Japanese Patent Laid-Open No. 9-109694

  However, the above-described Patent Document 1 does not describe a method for appropriately determining the failure of the lock mechanism.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for a hybrid vehicle that can appropriately determine a failure of a lock mechanism.

In one aspect of the present invention, a control device for a hybrid vehicle is an engagement configured to be able to fix rotation of the first motor generator by engaging an engine and first and second motor generators. And is applied to a hybrid vehicle that switches between a continuously variable transmission mode and a fixed transmission mode using the engagement element, and the engagement mechanism fails when the hybrid vehicle is not driving. Failure determination means for determining whether the first motor generator is applied, and the failure determination means performs control to apply the torque of the first motor generator, and the rotation of the first motor generator is performed even when the torque is applied. When the number does not change, it is determined that the engagement mechanism has failed.

The control device for a hybrid vehicle has an engagement mechanism configured to be able to fix the rotation of the first motor generator, and switches between the continuously variable transmission mode and the fixed transmission mode using the engagement element. It is suitably applied to a hybrid vehicle. Specifically, the failure determination means determines whether or not the engagement mechanism has failed when the hybrid vehicle is not driving. Thereby, it is possible to appropriately determine the failure of the engaging element without causing the driver to feel uncomfortable during traveling. Preferably, the failure determination means performs control to apply the torque of the first motor generator, and if the rotation speed of the first motor generator does not change even when the torque is applied, the engagement mechanism fails. It is good to judge that it is.

  In one aspect of the hybrid vehicle control device, the failure determination means is at least one of the case where the brake is turned on and the shift range is set to the parking range while the engine is stopped. Then, it is determined whether or not the engagement mechanism has failed.

  According to this aspect, the failure of the engaging element can be appropriately determined while the hybrid vehicle is stopped.

  The control apparatus for a hybrid vehicle in the present invention has an engagement mechanism configured to be able to fix the rotation of the first motor generator, and switches between the continuously variable transmission mode and the fixed transmission mode using the engagement element. The present invention is preferably applied to a hybrid vehicle to be performed. Specifically, the failure determination means determines whether or not the engagement mechanism has failed when the hybrid vehicle is not driving. Thereby, it is possible to appropriately determine the failure of the engaging element without causing the driver to feel uncomfortable during traveling.

It is a figure showing the schematic structure of the hybrid vehicle concerning this embodiment. It is a figure for demonstrating the malfunction which generate | occur | produces when drive | working with a lock failure. It is a flowchart which shows the failure determination process of the locking mechanism in this embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[Device configuration]
FIG. 1 shows a schematic configuration of a hybrid vehicle to which the hybrid vehicle control device of the present embodiment is applied.

  FIG. 1 shows a hybrid vehicle called a mechanical distribution type two-motor type, and the hybrid vehicle includes an engine (internal combustion engine) 1, a first motor generator MG1, a second motor generator MG2, and a power distribution mechanism. 20.

  An engine 1 corresponding to a power source and a first motor generator MG1 are connected to a power distribution mechanism 20. A second motor generator MG2 that is a power source for assisting torque (driving force) or braking force of the driving shaft 3 is connected to the driving shaft 3 (so-called peller shaft) of the power distribution mechanism 20. . Further, the drive shaft 3 is connected to the left and right drive wheels 9 via a final speed reducer 8. The first motor generator MG1 and the second motor generator MG2 are electrically connected via a battery, an inverter, or an appropriate controller, or directly, and the first motor generator MG1 and the second motor generator MG2 generate electric power generated by the first motor generator MG1. The second motor generator MG2 is configured to be driven.

  The engine 1 is a heat engine that generates power by burning fuel, and examples thereof include a diesel engine and a gasoline engine. The first motor generator MG1 generates power mainly by receiving torque from the engine 1 and rotating, and a reaction force of torque accompanying power generation acts. By controlling the rotation speed of first motor generator MG1, the engine rotation speed of engine 1 changes continuously. Such a speed change mode is called a continuously variable speed change mode. The second motor generator MG2 is a device that assists (assists) driving force or braking force. When assisting the driving force, the second motor generator MG2 functions as an electric motor upon receipt of electric power. On the other hand, when assisting the braking force, the second motor generator MG2 functions as a generator that is rotated by the torque transmitted from the drive wheels 9 to generate electric power.

  The power distribution mechanism 20 is a so-called single pinion type planetary gear mechanism, and includes a ring gear R1, a carrier C1, and a sun gear S1. The carrier C1 holds a pinion gear CP1 that meshes with both the ring gear R1 and the sun gear S1.

  The output shaft 2 of the engine 1 is connected to the carrier C1 of the first planetary gear mechanism. One end of the rotor 11 of the first motor generator MG1 is connected to the sun gear S1 of the first planetary gear mechanism. The ring gear R1 is connected to the drive shaft 3. The first motor generator MG1 is provided with a resolver 45 configured to be able to detect the rotation of the first motor generator MG1 (specifically, the rotor 11). The resolver 45 supplies a detection signal Sig8 corresponding to the detected rotational speed to the ECU 4.

  The other end of the rotor 11 of the first motor generator MG1 is connected to the lock mechanism 7. The lock mechanism 7 mainly includes a clutch 7a and an actuator 7b. For example, the lock mechanism 7 is configured by a wet multi-plate clutch or the like, and is configured to be able to fix the rotor 11 of the first motor generator MG1 using a frictional force. The lock mechanism 7 functions as an engagement mechanism in the present invention.

  Specifically, in clutch 7a of lock mechanism 7, one clutch plate is fixed to a case or the like, and the other clutch plate is connected to rotor 11 of first motor generator MG1. The lock mechanism 7 is configured to be able to engage and disengage the clutch 7a using the actuator 7b. The lock mechanism 7 fixes the rotor 11 of the first motor generator MG1 and the sun gear S1 of the power distribution mechanism 20 by engaging the clutch 7a. In this case, the lock mechanism 7 functions as a frictional engagement element, for example, and sets the rotation speed of the rotor 11 in the first motor generator MG1 to “0 (rpm)”. Further, the lock mechanism 7 releases the engagement of the clutch 7a, thereby releasing the rotor 11 of the first motor generator MG1 and releasing the sun gear S1 of the power distribution mechanism 20. The lock mechanism 7 controls the engagement / release of the clutch 7a based on the control signal Sig5 transmitted from the ECU 4.

  In the state where the lock mechanism 7 is disengaging the clutch 7a, the engine speed of the engine 1 is continuously changed by continuously changing the rotation speed of the first motor generator MG1, thereby realizing the continuously variable transmission mode. Is done. On the other hand, when the lock mechanism 7 is engaged with the clutch 7a, the transmission ratio determined by the power distribution mechanism 20 is in an overdrive state (that is, the engine speed of the engine 1 is smaller than the speed of the drive shaft 3). The fixed shift mode is realized.

  The power supply unit 30 includes an inverter 31, a converter 32, an HV battery 33, and a converter 34. The first motor generator MG1 is connected to the inverter 31 by a power line 37, and the second motor generator MG2 is connected to the inverter 31 by a power line 38. The inverter 31 is connected to the converter 32, and the converter 32 is connected to the HV battery 33. Further, the HV battery 33 is connected to the auxiliary battery 35 via the converter 34.

  Inverter 31 exchanges power with motor generators MG1 and MG2. During regeneration of the motor generator, the inverter 31 converts the electric power generated by the motor generators MG1 and MG2 into the direct current and supplies the direct current to the converter 32. Converter 32 converts the electric power supplied from inverter 31 to charge HV battery 33. On the other hand, when the motor generator is powered, the DC power output from the HV battery 33 is boosted by the converter 32 and supplied to the inverter 31, and then supplied to the motor generator MG 1 or MG 2 via the power line 37 or 38.

  The electric power of the HV battery 33 is converted into a voltage by the converter 34 and supplied to the auxiliary battery 35, and used for driving various auxiliary machines.

  The operation of the inverter 31, the converter 32, the HV battery 33, and the converter 34 is controlled by the ECU 4. The ECU 4 controls the operation of each element in the power supply unit 30 by transmitting the signal Sig4. A necessary signal indicating the state of each element in the power supply unit 30 is supplied to the ECU 4 as a control signal Sig4. Specifically, SOC (State Of Charge) indicating the remaining battery capacity of the HV battery 33, input restriction / output restriction of the HV battery 33, and the like are supplied to the ECU 4 as a signal Sig4.

  The ECU (Electronic Control Unit) 4 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown). The ECU 4 controls them by transmitting and receiving control signals Sig1 to Sig3 among the engine 1, the first motor generator MG1, and the second motor generator MG2. Further, the ECU 4 performs control to switch engagement / release of the lock mechanism 7 by transmitting a control signal Sig 5 to the lock mechanism 7. In the present embodiment, the ECU 4 determines a failure of the lock mechanism 7 based on the detection signal Sig8 supplied from the resolver 45. Therefore, the ECU 4 corresponds to a failure determination unit in the present invention.

  Here, the reason for performing the failure determination of the lock mechanism 7 will be described. In the present embodiment, the ECU 4 makes a determination regarding a lock failure in the lock mechanism 7. The “lock failure” refers to a failure that hardens when the lock mechanism 7 is engaged. For example, the “lock failure” corresponds to a state where the lock mechanism 7 is erroneously engaged (hereinafter the same).

  With reference to FIG. 2, the malfunction which arises when drive | working with a lock failure is demonstrated concretely. 2A to 2C show examples of collinear diagrams when the lock mechanism 7 has a lock failure. Specifically, FIGS. 2A to 2C show the operation states of the first motor generator MG1, the engine 1, and the second motor generator MG2 (uniquely the drive shaft 3) in order from the left, respectively. A collinear diagram is shown. The vertical direction corresponds to the number of rotations, and the upward direction corresponds to the forward rotation.

  Fig.2 (a) has shown an example of the alignment chart at the time of vehicle advance at the time of a lock failure. When the lock mechanism 7 has a lock failure, as shown in FIG. 2 (a), the rotation speed of the first motor generator MG1 is maintained at approximately "0". The number may stay in the resonance band. In this case, a continuous load may be applied to the input shaft in the engine 1.

  FIG. 2B shows an example of a nomographic chart when the vehicle moves backward when a lock failure occurs. When the lock mechanism 7 has a lock failure, the rotation speed of the first motor generator MG1 is maintained at approximately “0”. Therefore, as shown in FIG. . In this case, there is a risk of poor lubrication in the engine 1.

FIG. 2C shows an example of a nomograph at the time of engine start at the time of lock failure. When the lock mechanism 7 is normal, cranking is started in the first motor generator MG1 in response to an engine start request, and the rotation speed of the first motor generator MG1 and the like changes. However, when the lock mechanism 7 has a lock failure, the rotation speed of the first motor generator MG1 is maintained at approximately “0”. Therefore, when the engine is started, as shown in FIG. Almost no change in the rotational speed of the motor generator MG1 or the like occurs. In this case, in the inverter of first motor generator MG1, there is a possibility that current concentrates on a specific phase (U, V, or W).
[Failure judgment method]
Next, a failure determination method for the lock mechanism 7 in the present embodiment will be described.

  In the present embodiment, the ECU 4 determines the failure of the lock mechanism 7 by applying the torque of the first motor generator MG1 (hereinafter referred to as “MG1 torque”). In this case, since the vehicle may move due to the reaction force, the ECU 4 determines the failure of the lock mechanism 7 when stopping and vehicle restraint can be guaranteed. Specifically, the ECU 4 determines a failure of the lock mechanism 7 when not driving. This is because the driving is not hindered, that is, the driver does not feel uncomfortable. Hereinafter, a condition used for determining whether or not lock failure detection may be performed is referred to as a “lock failure detection condition”. This lock failure detection condition is determined from the viewpoint that it does not interfere with traveling when a failure is detected (that is, the driver does not feel uncomfortable).

  Specifically, the ECU 4 performs control to apply the MG1 torque when such a lock failure detection condition is satisfied, and based on the detection signal Sig8 from the resolver 45 when the control is performed, the ECU 4 Perform failure determination. That is, the ECU 4 determines whether or not there is a change in the rotational speed (in other words, a change in position) of the first motor generator MG1 based on the detection signal Sig8 from the resolver 45, so that the lock failure of the lock mechanism 7 occurs. Is detected. Specifically, the ECU 4 determines that the lock mechanism 7 is normal when the rotation speed change of the first motor generator MG1 occurs, and the rotation speed change of the first motor generator MG1 does not occur. In this case, it is determined that there is a lock failure.

  When the lock mechanism 7 is normal, the lock mechanism 7 is released in a situation where the above-described lock failure detection condition is satisfied. Therefore, when the MG1 torque is applied, the rotation speed change of the first motor generator MG1 is changed. Will occur. On the other hand, when the lock mechanism 7 has a lock failure, the lock mechanism 7 is in a mis-engaged state. Therefore, even if MG1 torque is applied, the rotational speed change of the first motor generator MG1 is changed. Will not occur. Therefore, when the MG1 torque is applied, the ECU 4 determines that the lock mechanism 7 is normal when there is a change in the rotation speed of the first motor generator MG1, and the change in the rotation speed of the first motor generator MG1 occurs. If not, it is determined that there is a lock failure.

  And ECU4 restrict | limits the system operation | movement in a vehicle, when the lock failure of the lock mechanism 7 is detected as mentioned above. Specifically, the ECU 4 prohibits vehicle travel or engine start. By doing so, it is possible to appropriately prevent the occurrence of secondary defects in other components as described above.

  Here, specific examples (first to fourth examples) of the above-described lock failure detection condition will be described.

  In the first example, the start of a trip (in other words, the ignition key is turned on) is used as a lock failure detection condition. That is, the ECU 4 determines a failure of the lock mechanism 7 by applying MG1 torque as an initial check every time a trip is started. In the second example, turning on the P range while the engine is stopped is used as a lock failure detection condition. That is, the ECU 4 determines the failure of the lock mechanism 7 by applying the MG1 torque every time the shift range is set to the parking range (P) while the engine is stopped.

  In the third example, stopping by turning on a brake (foot brake) while the engine is stopped is used as a lock failure detection condition. That is, the ECU 4 determines a failure of the lock mechanism 7 by applying MG1 torque every time the brake is stopped while the engine is stopped. In the fourth example, use of a service tool for performing failure diagnosis or the like is used as a lock failure detection condition. That is, the ECU 4 applies the MG1 torque when a service tool (for example, TasCAN) is connected to the connector in the vehicle and the service tool requests the ECU 4 to detect a failure. Perform a failure judgment.

  Next, the failure determination process of the lock mechanism 7 in this embodiment will be described with reference to the flowchart shown in FIG. This process is repeatedly executed by the ECU 4 at a predetermined cycle.

  First, in step S101, the ECU 4 determines whether or not a lock failure detection condition is satisfied. That is, the ECU 4 determines whether or not the driver does not feel uncomfortable even when the lock failure is detected. For example, the ECU 4 determines whether or not at least one of the above-described first to fourth examples is satisfied. Specifically, the ECU 4 requests a failure detection from the service tool, whether the ignition key is turned on, whether the P range is set while the engine is stopped, whether the brake is stopped when the engine is stopped, or not. It is determined whether or not there is.

  If the lock failure detection condition is satisfied (step S101; Yes), the process proceeds to step S102. On the other hand, when the lock failure detection condition is not satisfied (step S101; No), the process proceeds to step S105. In this case, the ECU 4 performs normal traveling without performing failure determination of the lock mechanism 7 (step S105), and the process ends.

  In step S102, the ECU 4 performs control to apply MG1 torque. Specifically, ECU 4 controls first motor generator MG1 such that a predetermined torque that is set in advance is applied from first motor generator MG1. For example, the predetermined torque is set to a torque sufficient to overcome the friction torque in the shaft of first motor generator MG1 and rotate first motor generator MG1. Then, the process proceeds to step S103.

  In step S103, the ECU 4 determines whether or not a change in the rotational speed of the first motor generator MG1 has occurred based on the detection signal Sig8 supplied from the resolver 45. In other words, it is determined whether or not a position change has occurred in the first motor generator MG1.

  If there is a rotation speed change (step S103; Yes), the process proceeds to step S104. In this case, the ECU 4 determines that there is no lock failure (step S104). And a process progresses to step S105 and ECU4 implements normal driving | running | working. Thereafter, the process ends.

  On the other hand, when there is no rotation speed change (step S103; No), a process progresses to step S106. In this case, the ECU 4 determines that there is a lock failure (step S106). Then, the process proceeds to step S107. In step S107, the ECU 4 limits the system operation in the vehicle, that is, performs limited travel. Specifically, the ECU 4 prohibits vehicle travel or engine start. Then, the process ends.

  According to the failure determination process described above, it is possible to appropriately determine the lock failure of the lock mechanism 7 without causing the driver to feel uncomfortable during traveling. Further, by restricting the system operation in the case of a lock failure, it is possible to appropriately prevent problems occurring in other components.

1 Engine 3 Drive shaft 4 ECU
7 Lock mechanism 7a Clutch 20 Power distribution mechanism 33 HV battery 45 Resolver MG1 First motor generator MG2 Second motor generator

Claims (2)

An engagement mechanism configured to be able to fix the rotation of the first motor generator by engaging with the engine, and the first and second motor generators. Applies to hybrid vehicles that switch between step-speed mode and fixed-speed mode
A failure determining means for determining whether or not the engagement mechanism has failed when the hybrid vehicle is not driving ;
The failure determination means performs control to apply the torque of the first motor generator, and the engagement mechanism fails when the rotation speed of the first motor generator does not change even when the torque is applied. A control apparatus for a hybrid vehicle, characterized in that it is determined that   The failure determination means determines whether or not the engagement mechanism has failed when the brake is turned on and the shift range is set to the parking range while the engine is stopped. The control apparatus of the hybrid vehicle of Claim 1 which performs this determination.

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