JP5370673B2 - Hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle that controls an engine operating point in a vehicle powered by an engine and a motor generator.

Vehicles include a so-called hybrid vehicle that includes an engine and a motor generator (electric motor) in addition to the engine as a drive source to improve fuel efficiency.
In this hybrid vehicle, the target engine power of the engine is calculated by adding the power required by the engine to be output by the vehicle (hereinafter referred to as “vehicle required power”) and the required power generation power, so that the target engine power can be output. Of these points, the operating point at which the fuel consumption rate is minimum is set as the target operating point, and the engine torque and the motor generator torque are controlled so that the operating point of the engine becomes the target operating point.

JP 2007-191079 A

  The control device for a hybrid vehicle according to Patent Document 1 requires vehicle power so that the engine rotational speed and the motor rotational speed are the same when there is a margin in the state of charge (SOC) of the battery during acceleration of the vehicle. Accordingly, a target engine speed and a target engine torque are calculated by an engine operating point search map (see FIG. 5), and control is performed based on the calculated target engine speed and target engine torque.

  By the way, conventionally, in the control of a hybrid vehicle, the vehicle required power is a value representing the driver's intention, and even if the target engine power increases due to an increase in the vehicle required power, there is no sense of incongruity, but there is no problem. The generated power is determined mainly by the state of charge of the battery and is determined regardless of the driver's intention. Therefore, when shifting from the “P” range to the “R” range, the target generated power in the “P” range is set to “R”. The engine speed is suddenly increased because it is set lower than the “range”, and power generation is not performed in the “N” range, so the “N” range is shifted to the “D” range. Even in such a case, the engine speed rapidly increases, and drivability deteriorates.

  Therefore, the present invention provides a hybrid vehicle that aims to limit the amount of increase (decrease) in target power generation per hour to the target power generation power that changes in accordance with the state of charge (SOC) of the battery. It is to provide.

The present invention provides a hybrid vehicle that outputs power generated from an engine and a motor generator to a drive shaft via a power transmission mechanism, and includes a required drive force setting unit that sets a required drive force in response to a driver's request. a control means for controlling and the motor-generator is controlled so as to output a target generated power to the engine so that the required driving force set by the required driving force setting means outputs the target engine power provided, wherein control means comprises a charging state detecting means for detecting a state of charge of the battery, and a target generated power calculating means for calculating a target generated power in accordance with the state of charge of the battery detected by the charge state detecting means, wherein The target generated power calculating means is configured to calculate one cycle of the calculated target generated power and the calculated target generated power. The required power generation power change amount is calculated from the value of the calculated power generation power change, and the calculated target power generation power is greater than a value of the calculated target power generation power one cycle before, When the amount is equal to or less than a preset limit value, control is performed so that the calculated target generated power can be output, and the calculated required generated power change amount exceeds the preset limit value. Is provided with limit control output means for performing control so that a value obtained by adding the preset limit value to a value one cycle before the calculated target generated power can be output as the target generated power. And

  The hybrid vehicle of the present invention performs limit control so that the value of the target generated power does not change abruptly, eliminating the need to change the value of the target engine power abruptly, thereby contributing to the improvement of drivability. Make it possible.

FIG. 1 is a flowchart of control in the control means. (Example) FIG. 2 is a time chart of control in the control means. (Example) FIG. 3 is a system configuration diagram of the control apparatus for the hybrid vehicle. (Example) FIG. 4 is a block diagram of the control means. (Example) FIG. 5 is a diagram of an engine operating point search map. (Example)

The present invention achieves the object of improving drivability without the need to change the target engine power value rapidly by restricting the target generated power value so that it does not change suddenly.
Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

1 to 5 show an embodiment of the present invention.
In FIG. 3, 1 is an engine mounted on a hybrid vehicle as a vehicle, and 2 is a control device for the hybrid vehicle.
The control device 2 includes an output shaft 3 of an engine 1 that is a driving source for outputting torque, a first motor generator 4 and a second motor generator 5 as motor generators, and a transmission gear mechanism 7 for driving wheels 6. And a power transmission mechanism (differential gear mechanism) 9 coupled to the output shaft 3, the first motor generator 4, the second motor generator 5, and the drive shaft 8, respectively. ing.
The control device 2 also includes a first inverter 10 that controls the operation of the first motor generator 4, a second inverter 11 that controls the operation of the second motor generator 5, the first inverter 10, and the second inverter Control means 12 communicated with the inverter 11 is provided. Each power supply terminal of the first inverter 10 and the second inverter 11 is connected to a battery 13 as a power storage device.

  The power transmission mechanism 9 is a so-called four-shaft power input / output device, which includes the output shaft 3 and the drive shaft 8 of the engine 1, and the first motor generator 4 on the engine 1 side and the drive shaft 8 side. The second motor generator 5 is arranged, the power of the engine 1, the power of the first motor generator 4 and the power of the second motor generator 5 are combined and output to the drive shaft 8, and the engine 1 and the first motor generator 5 are combined. Power is transferred between the first motor generator 4, the second motor generator 5, and the drive shaft 8.

The power transmission mechanism 9 is configured by arranging a first planetary gear mechanism 14 and a second planetary gear mechanism 15 in which two rotation elements are connected to each other.
The first planetary gear mechanism 14 includes a first sun gear 16, a first pinion gear 17 that meshes with the first sun gear 16, and a first ring gear 18 that meshes with the first pinion gear 17. And a first carrier 19 connected to the first pinion gear 17.
The second planetary gear mechanism 15 includes a second sun gear 20, a second pinion gear 21 meshed with the second sun gear 20, and a second ring gear 22 meshed with the second pinion gear 21. , And a second carrier 23 connected to the second pinion gear 212.

In the power transmission mechanism 9, the first carrier 19 of the first planetary gear mechanism 14 is connected to the output shaft 3 of the engine 1, and the second carrier 23 of the second planetary gear mechanism 15 is The first planetary gear mechanism 14 is connected to the first ring gear 18.
A first motor generator 4 is connected to the first sun gear 16 via a first motor output shaft 24. The output shaft 3 of the engine 1 is connected to the first carrier 19 and the second sun gear 20. The drive shaft 8 is connected to the first ring gear 18 and the second carrier 23 via the transmission gear mechanism 7. The second motor generator 5 is connected to the second ring gear 22 via the second motor output shaft 25.
The second motor generator 5 is configured to drive wheels via a second motor output shaft 25, a second ring gear 22, a second carrier 23, a first ring gear 18, a transmission gear mechanism 7, and a drive shaft 8. 6 can be directly connected to the vehicle, and the vehicle can be driven only by a single output.
That is, in the power transmission mechanism 9, the first carrier 19 of the first planetary gear mechanism 14 and the second sun gear 20 of the second planetary gear mechanism 15 are coupled and connected to the output shaft 3 of the engine 1. The first ring gear 18 of the first planetary gear mechanism 14 and the second carrier 23 of the second planetary gear mechanism 15 are coupled and connected to the drive shaft 8, and the first planetary gear mechanism 14 The first motor generator 4 is connected to one sun gear 16, the second motor generator 5 is connected to the second ring gear 22 of the second planetary gear mechanism 15, the engine 1, the first motor generator 4, Power is exchanged between the second motor generator 5 and the drive shaft 8.

As shown in FIG. 4, the control means 12 communicates with an engine speed sensor 26 that detects the engine speed and an accelerator sensor 27 that detects the amount of depression of the accelerator pedal as the accelerator opening, and responds to the driver's request. Required driving force setting means 28 for setting the required driving force to control the engine 1 to output the target engine power so as to obtain the required driving force set by the required driving force setting means 28 and the first The motor generator 4 and the second motor generator 5 are controlled so as to output the target power generation power.
The control means 12 outputs a predetermined control value for operating the first motor generator 4 and the second motor generator 5 to control the operation of the first inverter 10 and the second inverter 11, as well as the engine 1. To control the operation.
Further, the battery 13 has a function of storing electricity when the first motor generator 4 and the second motor generator 5 are regenerated.

Further, as shown in FIG. 4, the control unit 12 includes a charge state detection unit 29 that communicates with the battery 13 and detects the state of charge (SOC) of the battery 13, and is detected by the charge state detection unit 29. A target generated power calculating means 30 for calculating a target generated power (P_req) according to the state of charge of the battery 13 is provided, and the target generated power (P_req) calculated this time and the previously calculated target generated power (P_req_out_prev) When the difference (change amount: (P_dif)) is less than a preset limit value (upl), control is performed so that the target power generation power calculated this time can be output, and the target power generation power (P_req) calculated this time. The difference (change amount: (P_dif)) from the previously calculated target generated power (P_req_out_prev) is preset. When the limit value (upl) is exceeded, the control is performed so that a value obtained by adding a preset limit value (upl) to the previously calculated target generated power (P_req_out_prev) can be output as the current target generated power Control output means 31 is provided, and control value output means 32 for outputting control values to the engine 1, the first generator 4, and the second generator 5 is further provided.
The target generated power calculation means 30 communicates with a shift position detection sensor 33 that detects the shift position (shift position) and searches for the target generated power according to the state of charge (SOC) of the battery 13. A search map 34 is provided. Therefore, the target generated power is also calculated according to the shift position.
The limit control output unit 31 includes a storage unit (memory) 35 that communicates with the shift position detection sensor 33 and stores various calculated values.
The limit control output means 31 varies the value of the limit value depending on whether the difference between the currently generated target generated power and the previously calculated target generated power is a positive value or a negative value.
Further, the limit control output means 31 is executed in accordance with a change in the shift position.

  Further, the control means 12 incorporates an engine operating point search map as shown in FIG. In the engine operating point search map of FIG. 5, the target engine speed and the target engine torque are calculated according to the power to be output from the engine 1 required by the vehicle (hereinafter referred to as “vehicle required power”). Is used to control the engine 1, the motor generator 4 and the motor generator 5.

Next, the control of this embodiment will be described based on the flowchart of FIG.
The routine in FIG. 1 is periodically executed (for example, every 20 ms), and the calculated target generated power (P_req_out) is periodically updated.
As shown in FIG. 1, when the program of the control means 12 is started (step A01), first, the target generated power (P_req) is searched by the target generated power search map 34 according to the state of charge (SOC) (step A02). A required power generation power change amount (P_dif) is calculated from the retrieved target power generation power (P_req) and a value (P_req_out_prev) one cycle before the calculated target power generation power (P_req_out) calculated as a calculation result of this routine. (Step A03).
This required power generation change amount (P_dif) is
P_dif = P_req−P_req_out_prev
Is calculated by
Then, it is determined whether or not the required power generation change amount (P_dif) is positive (P_req is larger than the calculated target power generation value ( P_req_out_prev ) one cycle before) (step A04).
If this step A04 is YES, it is determined whether or not the required power generation power change amount (P_dif) is larger than the target power generation power increase limit value (upl) (step A05).
When this step A05 is YES, the increase amount is limited by the target generation power increase amount limit value (upl) with reference to the value (P_req_out_prev) one cycle before the calculated target generation power (P_req_out) (step A06). ).
P_req_out = P_req_out_prev + upl
If step A05 is NO, no such restriction is imposed (step A07).
P_req_out = P_req
On the other hand, if step A04 is NO, it is determined whether the required power generation power change amount (P_dif) is larger than the target power generation power reduction amount limit value (dl) (step A08).
When this step A08 is NO, the reduction amount is limited by the target generation power reduction amount limit value (dl) with reference to the value (P_req_out_prev) one cycle before the calculated target generation power (P_req_out) (step A09). ).
P_req_out = P_req_out_prev + dl
If step A08 is YES, no such restriction is imposed (step A07).
P_req_out = P_req
Then, after the process of Step A06, after the process of Step A07, or after the process of Step A09, a calculated target generated power (P_req_out) is calculated (Step A10), and the calculated calculated target generated power ( P_req_out) and the target drive power are calculated, the vehicle required power is calculated, the target engine speed (Ne) and the target engine torque (Te) are calculated using an engine operating point search map as shown in FIG. This calculated target generated power (P_req_out) is temporarily stored in the storage means 35. Next, when this flowchart is executed, the calculated target generated power (P_req_out) Used as a value (P_req_out_prev) one cycle before.
Then, the program is returned (step A11).

FIG. 2 shows a control time chart of this embodiment.
In the time chart of FIG. 2, for comparison, it is assumed that P_req_out in the absence of this control is the target generated power P_req, and in the presence of this control, P_req_out has been processed as described above. The graph is divided as “conventional example” when there is no main control, and “present example” when there is main control.
In the time chart in FIG. 2, the time 0 to T1 is the “P” range, the time T1 to T2 is the “R” range, the time T2 to T3 is the “N” range, and the time after the time T3 is the “D” range. I think it ’s shifting. In each range, the target generated power changes. Also, “Ne_id” on the target engine speed axis is the idling engine speed. When the shift is changed to the “N” range, the target generated power is forcibly set to zero (0), the engine speed is set to “Ne_id”, and the engine torque is set to zero (0).
In the conventional example, when the “P” range is changed to the “R” range (time T1), the calculated target generated power changes from PreqA to PreqB. As a result, the target engine speed changes rapidly from Ne_A to Ne_B in accordance with the engine operating point search map of FIG. Similarly, when changing from the “N” range to the “D” range (time T3), the target engine speed changes rapidly from Ne_id to Ne_B.
On the other hand, in the present embodiment, when the “P” range is changed to the “R” range (time T1), the calculated target generated power tends to change from PreqA to PreqB. In order to surpass, the amount of increase is limited, and this is a gradual change. Similarly, when changing from the “N” range to the “D” range (time T3), the target engine speed slightly changes from Ne_id and then gradually changes.

As a result, in this embodiment, the control means 12 calculates the target power generation power calculated this time when the difference between the target power generation power calculated this time and the target power generation power calculated last time is less than a preset limit value. If the difference between the target generated power calculated this time and the previously calculated target generated power exceeds a preset limit value, the target generated power calculated previously is set in advance. There is provided limit control output means 31 for controlling so that a value obtained by adding the limit value can be output as the current target generated power. That is, the result of limiting the amount of change so that the calculated target generated power does not change rapidly is used as the final target generated power for searching the engine operating point.
As a result, limit control is performed so that the value of the target generated power does not change suddenly, so even if the target generated power, which is one of the factors for searching for the engine operating point, suddenly changes, this is handled. Therefore, it is not necessary to change the target engine power value rapidly. Therefore, it is possible to prevent the target engine speed and the target engine torque from changing suddenly. Thereby, it is possible to contribute to the improvement of drivability.
Further, the limit control output unit 31 varies the value of the limit value depending on whether the difference between the target generated power calculated this time and the previously calculated target generated power is a positive value or a negative value. That is, different limits of change are used when the target power generation power increases and when the target power generation power decreases.
As a result, when the amount of positive change (when the generated power increases), which is very uncomfortable for the driver, is large, a smaller limit value is used, so the degree of freedom of adaptation can be expanded and drivability is improved. Can contribute.
Further, the limit control output means 31 is executed in accordance with the change of the shift position.
As a result, even when the neutral (N) range or the parking (P) range is shifted to the travel (D) range, it is possible to realize smooth control in which the engine speed does not change suddenly.
Furthermore, in the control means 12, by setting the limit of the change amount when the target power generation power increases to be smaller than the limit of the change amount when the target power generation power decreases, there is a greater sense of discomfort. The change when the engine speed increases can be reduced.

  The hybrid vehicle control device according to the present invention can be applied to various vehicles.

DESCRIPTION OF SYMBOLS 1 Engine 2 Control apparatus of hybrid vehicle 3 Engine output shaft 4 1st motor generator 5 2nd motor generator 8 Drive shaft 9 Power transmission mechanism 10 1st inverter 11 2nd inverter 12 Control means 13 Battery 14 1st Planetary gear mechanism 15 second planetary gear mechanism 27 accelerator sensor 28 required driving force setting means 29 charge state detection means 30 target generated power calculation means 31 limit control output means 32 control value output means 33 shift position detection sensor

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,
The engine is controlled to output the target engine power is to be required driving force set by the required driving force setting means comprises a driving force demand setting module that sets a required driving force in response to a request of the driver And a control means for controlling the motor generator so as to output the target power generation power,
Wherein said control means comprises a charging state detecting means for detecting a state of charge of the battery, and a target generated power calculating means for calculating a target generated power in accordance with the state of charge of the battery detected by the charge state detecting means,
The target generated power calculation means is
Calculating a required power generation power change amount from the calculated target power generation power and a value of one cycle before the calculated target power generation power,
The calculated target generated power is greater than a value one cycle before the calculated target generated power;
If the calculated required power generation power change amount is less than or equal to a preset limit value, control to output the calculated target power generation power,
When the calculated required power generation power change amount exceeds the preset limit value, a value obtained by adding the preset limit value to a value one cycle before the calculated target power generation power is obtained. A hybrid vehicle characterized by comprising restriction control output means for controlling so as to be able to output as target generated power. The hybrid vehicle according to claim 1 , wherein the restriction control output unit is executed in accordance with a change in shift position.

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