JP2011037323A - Hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent occurrence of a driving force generated by execution of feedback control of a motor generator for making actual engine speed close to a target engine speed, prevent battery overcharge occurring in a parking range, and prevent over speed of a motor generator. <P>SOLUTION: A hybrid vehicle includes a target driving force setting means, a driving force control means, a feedback control means for feedback-controlling the motor generator to eliminate deviation of the actual engine speed from the target engine speed, a range detecting means for detecting whether the shift position is the parking range or a neutral range, and a restricting means for restricting the execution of the feedback control by the feedback control means when the shift position is determined to be the parking range or the neutral range and engine operation mode is determined. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle that can prevent over-rotation of a motor generator of a hybrid vehicle that uses an engine and a motor generator as power sources.

  Conventionally, in order to improve fuel efficiency, hybrid vehicles equipped with a motor generator in addition to an engine as a power source have various methods depending on the arrangement of the engine and the motor and the difference in the power transmission mechanism. Hybrid vehicle having one motor generator and one planetary gear mechanism arranged between the two motor generators (Patent Document 1, Patent Document 2), between the two motor generators connected to the engine and the two motor generators There is known a hybrid vehicle (Patent Document 3) that includes two planetary gear mechanisms arranged on the vehicle.

  In the hybrid vehicle described in Patent Document 3, the target driving force and the target driving power are calculated based on the accelerator opening, the vehicle speed, and the shift position, and the operating point of the engine is set based on them. The two motor generators are controlled to balance torque and rotational speed so that the driving force required by the driver can be achieved while maintaining the most efficient operating point. At this time, the motor generator is torque-corrected by feedback control so that the deviation between the actual engine speed and the target engine speed is zero. (Patent Document 4)

JP-A-11-150806 JP 2000-32611 A JP 2002-281607 A Japanese Patent Laid-Open No. 200-296937

However, in the control of the motor generator by the conventional hybrid vehicle, when the shift position is the parking (P) range or the neutral (N) range and the engine is in the idle state, even if the actual engine rotation speed slightly varies, The motor generator outputs torque by feedback control in an attempt to bring the rotation speed closer to the target engine rotation speed.
In the case of this hybrid vehicle, two motor generators are controlled when switching from the drive state of the drive (D) range and the reverse (R) range to the neutral (N) range and the non-drive state of the parking (P) range. Thus, the torque applied to the drive shaft is controlled to be zero, and the power source and the drive shaft are not mechanically separated by the clutch.
Therefore, in this hybrid vehicle, there is a possibility that torque is generated on the drive shaft even though the shift position is in the neutral (N) range and the parking (P) range, and parking (P) There is no particular problem because the output shaft is fixed in the range, but there is a problem that the vehicle starts to move in the neutral (N) range where the output shaft is not fixed.
As a method for solving this problem, in the neutral (N) range, the motor generator does not perform feedback control to bring the actual engine speed close to the target engine speed at all, and the motor generator torque is always set to zero. Can be considered. However, in this case, there is a problem that the motor generator may be over-rotated when the engine is blown up due to engine misalignment or the like.

On the other hand, in a hybrid vehicle, idle driving for engine warm-up may be required when it is not necessary to charge the battery even in the parking (P) range. In this case, if engine speed control by ISC (idle speed control) is not performed, if the engine output is excessive, the battery may be overcharged by controlling the engine speed by the motor generator. For this reason, it may be necessary to control the torque of the motor generator to 0 even in the parking (P) range.
Also in this case, there is a problem that the motor generator may be over-rotated when the engine is blown up due to poor adjustment of the engine or the like as in the neutral (N) range.

  The present invention prevents the generation of driving force caused by the feedback control of the motor generator for bringing the actual engine rotation speed close to the target engine rotation speed, and in particular prevents the battery from being overcharged in the parking range. The purpose is to prevent over-rotation of the generator.

  The present invention provides a target driving force setting means for setting a target driving force according to a driver's request in a hybrid vehicle that outputs power generated from an engine and a motor generator to a driving shaft via a power transmission mechanism. A driving force control means for controlling the engine and the motor generator so as to achieve a target driving force set by the target driving force setting means, and eliminating a deviation between the target engine speed and the actual engine speed. Feedback control means for feedback-controlling the motor generator as described above, and further comprising range detection means for detecting whether the shift position is a parking range or a neutral range, and the shift position is determined by the range detection means. The neutral range is determined and the engine operation mode is If it is determined that the de is characterized in that it comprises limiting means for limiting the implementation of the feedback control by the feedback control means.

  The hybrid vehicle of the present invention can prevent the generation of driving force caused by the feedback control of the motor generator for bringing the actual engine speed close to the target engine speed. In particular, it is possible to prevent overcharging of the battery that occurs in the parking range, and it is possible to prevent over-rotation of the motor generator.

1 is a system configuration diagram of a hybrid vehicle. (Example) It is a control flowchart of a hybrid vehicle. (Example) It is a figure which shows the area | region of the torque correction by a 1st motor generator upper-lower limit rotational speed and feedback control. (Example) It is a figure which shows the torque correction amount by the feedback control of a 1st motor generator. (Example)

The hybrid vehicle according to the present invention prevents the generation of driving force and the overcharging of the battery caused by the feedback control of the motor generator.
Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a hybrid vehicle drive control device. The drive control device 1 includes, as a drive system, an output shaft 3 of an engine 2 that generates a drive force by burning fuel, a first motor generator 4 that generates a drive force by electricity, and an electric energy by drive, and a second motor generator 4. The motor generator 5, the drive shaft 7 connected to the drive wheel 6 of the hybrid vehicle, the output shaft 3, the first motor generator 4, the second motor generator 5, and the first of the power transmission mechanism connected to the drive shaft 7, respectively. A planetary gear mechanism 8 and a second planetary gear mechanism 9 are provided.
The engine 2 includes an air amount adjusting means 10 such as a throttle valve that adjusts the amount of air to be sucked in response to the amount of depression of an accelerator pedal and engine requirements, a fuel injection valve that supplies fuel corresponding to the amount of air to be sucked, etc. Fuel supply means 11 and ignition means 12 such as an ignition device for igniting the fuel. The engine 2 is controlled in the combustion state of the fuel by the air amount adjusting means 10, the fuel supply means 11, and the ignition means 12, and generates a driving force by the combustion of the fuel.
The first motor generator 4 includes a first motor rotor shaft 13, a first motor rotor 14, and a first motor stator 15. The second motor generator 5 includes a second motor rotor shaft 16, a second motor rotor 17, and a second motor stator 18. The first motor stator 15 of the first motor generator 4 is connected to the first inverter 19. The second motor stator 18 of the second motor generator 5 is connected to the second inverter 20. The first motor generator 4 and the second motor generator 5 control the amount of electricity supplied from the battery 21 by the first inverter 19 and the second inverter 20, respectively, and generate driving force by the supplied electricity. Electric energy is generated by driving during regeneration from the drive wheel 6 to charge the battery 21.

The first planetary gear mechanism 8 includes a first sun gear 22, a first planetary carrier 24 that supports a first planetary gear 23 that meshes with the first sun gear 22, and a first ring gear 25 that meshes with the first planetary gear 23. It has. The second planetary gear mechanism 9 includes a second sun gear 26, a first planetary carrier 28 that supports a second planetary gear 27 that meshes with the second sun gear 26, and a second ring gear 29 that meshes with the second planetary gear 27. It has.
The first planetary gear mechanism 8 and the second planetary gear mechanism 9 are arranged such that the rotation center lines of the rotating elements are arranged on the same axis, and the first motor generator 4 is disposed between the engine 2 and the first planetary gear mechanism 8. The second motor generator 5 is arranged on the side away from the engine 2 of the second planetary gear mechanism 9. The first motor generator 4 is mainly operated for charging the battery 21. The second motor generator 5 has a performance capable of running the hybrid vehicle only with a single output, and is mainly operated for running the hybrid vehicle.
A first motor rotor shaft 13 of the first motor generator 4 is connected to the first sun gear 22 of the first planetary gear mechanism 8. The first planetary carrier 24 of the first planetary gear mechanism 8 and the second sun gear 26 of the second planetary gear mechanism 9 are coupled and connected to the output shaft 3 of the engine 2. The first ring gear 25 of the first planetary gear mechanism 8 and the second planetary carrier 28 of the second planetary gear mechanism 9 are coupled and connected to the output portion 30 of the output gear cylinder, and the output portion 30 is connected to a gear or chain. The output shaft is connected to the drive shaft 7 via an output transmission mechanism 31. The second motor rotor shaft 16 of the second motor generator 5 is connected to the second ring gear 29 of the second planetary gear mechanism 9.
As a result, in the drive system of the hybrid vehicle, the driving force is exchanged among the engine 2, the first motor generator 4, the second motor generator 5, and the drive shaft 7.

The air amount adjusting means 10, the fuel supply means 11, the ignition means 12, the first inverter 19 of the first motor generator 4, and the second inverter 20 of the second motor generator 5 of the internal combustion engine 2 are the drive control device 1. Is connected to a drive control unit 32 which is a control system.
The drive control unit 32 is connected to an accelerator detection unit 33, a vehicle speed detection unit 34, an engine rotation speed detection unit 35, and a shift position switch 36. The accelerator detection means 33 detects the amount of depression of the accelerator pedal. The vehicle speed detection means 34 detects the vehicle speed of the hybrid vehicle. The engine speed detection means 35 detects the engine speed of the engine 2. The shift position switch 36 outputs a signal indicating the position of the shift lever selected and operated by the driver.
The drive control unit 32 includes target drive force setting means 37, drive force control means 38, feedback control means 39, range detection means 40, and restriction means 41.
The target driving force setting means 37 is a target for driving the hybrid vehicle according to the accelerator pedal depression amount detected by the accelerator detecting means 33 and the vehicle speed detected by the vehicle speed detecting means 34. The driving force is determined by a preset target driving force search map. The driving force control means 38 is configured so that the driving force transmitted from the driving shaft 7 to the driving wheel 6 becomes the target driving force set by the target driving force setting means 37 and the first and second motors. The torque with the generators 4 and 5 is controlled.
Since there are an infinite number of combinations of torque between the engine 2 and the first and second motor generators 4 and 5, the respective torque distributions are determined depending on the state of charge of the battery 21 and the traveling state of the hybrid vehicle. If the engine is not required, the engine 2 is stopped to improve fuel efficiency.

The feedback control means 39 feedback-controls the torques of the first and second motor generators 4 and 5 so as to eliminate the deviation between the target engine speed and the actual engine speed. The range detection means 40 detects from the signal indicating the position of the shift lever output from the shift position switch 36 whether the shift position is in the parking (P) range or the neutral (N) range.
The limiting means 41 is an engine operation mode in which the shift position is determined by the range detection means 40 to be the parking (P) range or the neutral (N) range, and the hybrid vehicle is driven by the output of the engine 2. If it is determined, the feedback control means 39 limits the implementation of feedback control. The restricting means 41 executes the restriction except when the motor generator rotation speed values of the first and second motor generators 4 and 5 are close to the motor generator upper / lower limit rotation speed.
For example, as shown in FIGS. 3 and 4, the limiting means 41 is configured such that the motor generator rotational speed value of the first motor generator 4 is a value close to the motor generator upper limit rotational speed E (region from D to E). When the value is close to the motor generator lower limit rotation speed B (region from B to C), the feedback control means 39 permits the feedback control of the first motor generator 4 to be performed. Thereby, the feedback control means 39 corrects the torque of the first motor generator 4 so as to eliminate the deviation between the target engine speed and the actual engine speed in the range from D to E and from B to C. Do.
On the other hand, as shown in FIG. 3 and FIG. 4, the limiting means 41 has a value of the motor generator rotational speed of the first motor generator 4 that is close to the motor generator upper limit rotational speed E (area from D to E), and When the value is close to the motor generator lower limit rotational speed B (region from B to C) (region from C to D), the feedback control of the first motor generator 4 by the feedback control means 39 is restricted. Thereby, the feedback control means 39 sets the torque correction amount of the first motor generator 4 to 0 in the region from C to D.
The restricting means 41 permits and restricts the feedback control by the feedback control means 39 for the second motor generator 5 as well as the first motor generator 4.

Next, the operation will be described.
As shown in FIG. 2, the hybrid vehicle drive control device 1 starts control (S01), and determines whether the current running state is the engine operation mode (S02).
It is determined whether or not (mode control: idle control) is permitted (S03). ISC (idle control) is permitted when the shift position is in the parking (P) range or neutral (N) range, and the low vehicle speed state where the vehicle speed is equal to or less than the set vehicle speed continues for a certain period of time and is determined to be in the idle state. The
If the determination (S03) is YES and the ISC is permitted, the torque correction of the feedback control based on the engine speed deviation of the first and second motor generators 4 and 5 at the time of the ISC is permitted. Only when the speed is near (S04), the current process is terminated and the process returns (S05).
If the determination (S03) is NO and the ISC is not permitted, feedback control torque correction based on the engine speed deviation of the first and second motor generators 4 and 5 is performed regardless of the motor generator speed (S06). Then, the current process is terminated and the process returns (S05).
On the other hand, in the case of the motor operation mode in which the determination (S02) is NO and the hybrid vehicle is driven by the outputs of the first and second motor generators 4 and 5, the motor operation mode and the engine rotation speed Ne exceed the determination value A. (S07).
If this determination (S07) is YES and the motor operation mode is Ne> A, torque correction for feedback control based on the engine rotational speed deviation of the first and second motor generators 4 and 5 is performed regardless of the motor generator rotational speed. (S06), the current process is terminated and the process returns (S05).
If this determination (S07) is NO and the motor operation mode is not Ne> A, feedback correction torque correction based on the engine speed deviation of the first and second motor generators 4 and 5 is not performed (S08). The process ends and returns (S05).

Thus, the hybrid vehicle is in the engine operation mode in which the shift unit is determined to be in the parking (P) range or the neutral (N) range by the limiting means 41 and the hybrid vehicle is driven by the output of the engine 2. Is determined, the feedback control unit 39 restricts the implementation of feedback control.
For this reason, this hybrid vehicle generates the driving force that occurs in the neutral (N) range by performing the feedback control of the first and second motor generators 4 and 5 to bring the actual engine speed close to the target engine speed. It is possible to prevent. In particular, this hybrid vehicle overcharges the battery 21 generated in the parking (P) range by performing feedback control of the first and second motor generators 4 and 5 to bring the actual engine speed close to the target engine speed. Can be prevented.
Further, the hybrid vehicle executes the limitation by the limiting means 41 except when the motor generator rotation speed value of the first and second motor generators 4 and 5 is a value close to the motor generator upper and lower limit rotation speed. When the value is close to the generator upper / lower limit rotation speed, the feedback control means 39 is allowed to perform the feedback control, so that it is possible to prevent the driving force from occurring in the neutral (N) range and to generate in the parking (P) range. It is possible to prevent the first and second motor generators 4 and 5 from over-rotating while preventing overcharging of the battery 21 to be performed.

  The hybrid vehicle of the present invention can prevent the generation of driving force and the overcharge of the battery caused by the feedback control based on the engine rotational speed deviation of the first and second motor generators. Can be applied.

DESCRIPTION OF SYMBOLS 1 Drive control apparatus 2 Engine 4 1st motor generator 5 2nd motor generator 7 Drive shaft 8 1st planetary gear mechanism 9 2nd planetary gear mechanism 10 Air quantity adjustment means 11 Fuel supply means 12 Ignition means 19 1st inverter 20 2nd Inverter 21 Battery 32 Drive control unit 33 Accelerator detection means 34 Vehicle speed detection means 35 Engine rotation speed detection means 36 Shift position switch 37 Target drive force setting means 38 Drive force control means 39 Feedback control means 40 Range detection means 41 Limiting means

Claims (2)

In a hybrid vehicle that outputs power generated from an engine and a motor generator to a drive shaft via a power transmission mechanism,
Provided with a target driving force setting means for setting a target driving force according to a driver's request;
Driving force control means for controlling the engine and the motor generator so as to achieve the target driving force set by the target driving force setting means;
Feedback control means for feedback-controlling the motor generator so as to eliminate the deviation between the target engine speed and the actual engine speed,
Provided with range detection means for detecting whether the shift position is a parking range or a neutral range,
Limiting means for limiting the execution of feedback control by the feedback control means when the shift detection means determines that the shift position is the parking range or the neutral range and is in the engine operation mode. A hybrid vehicle comprising:   2. The hybrid vehicle according to claim 1, wherein the limiting unit executes the limitation except when the value of the motor generator rotational speed is a value close to the motor generator upper and lower limit rotational speed.

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