JP3707543B2 - Control device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller for a hybrid vehicle, which suppresses the input/output of an excessive electric power to/from a battery in deceleration (when fuel is shut off). SOLUTION: The control unit 10 judges a fuel shut off state of an engine 1 based on the driving condition at present running, and shut off the fuel to be supplied to the engine 1 with a time lag according to the permissible input/ output power to/from the battery 9, thereby reducing the input/output level to/from the battery 9 caused by the timing lag between the control of a generator and that of a motor.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hybrid vehicle.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 11-14650 discloses a technique for generating necessary electric power based on a vehicle running state with the aim of improving efficiency in a series type hybrid vehicle. Although the output of the motor changes from moment to moment as the driving state changes, if power can be supplied from the generator in real time in response to the change in output, the power loss in the battery is minimized and the engine Can be efficiently transmitted to the electric motor.
[0003]
[Problems to be solved by the invention]
In the above vehicle, the electric power used by the electric motor is supplied from the generator in real time, and the charging / discharging of the battery is minimized, thereby not only reducing the power loss but also minimizing the battery mounting capacity. . Since the battery occupies a large cost and weight ratio in the hybrid vehicle, if the battery can be reduced in size, not only the cost but also the fuel efficiency and the power performance can be obtained.
[0004]
On the other hand, however, the following problems occur when the battery mounting capacity is reduced. In other words, when the motor is powering as when the vehicle is accelerating, it is sufficient to supply the necessary power from the generator in real time as described above. However, if the motor regenerates power during deceleration, the battery is small. There is a problem that it is impossible to store all the regenerative power.
[0005]
Therefore, in Japanese Patent Laid-Open No. 8-79914, when the regenerative power becomes excessive at the time of deceleration, the power is consumed by rotating the engine by powering the generator to prevent the battery from being overcharged. are doing.
[0006]
However, in many cases, the fuel supplied to the engine is cut during deceleration to maintain good fuel economy. At the time of this fuel cut, the engine torque decreases instantaneously, the motor that has been powering up to that point is driven from the output shaft and shifts to the power generation state instantaneously, and the generator that has been generating power until then is instantaneously Transition to power running state. If there is a shift in the timing of each transition from power generation to power generation of this motor, the difference between the generated power and the power consumption will increase momentarily, and excessive power will be input and output to the battery. To promote battery deterioration.
[0007]
Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a hybrid vehicle that suppresses excessive power input / output to / from a battery at the time of fuel cut.
[0008]
[Means for Solving the Problems]
A first invention includes an engine, a generator coupled to the output shaft of the engine, an electric motor coupled to a drive shaft of a vehicle, a battery connected to the generator and the electric motor, In a hybrid vehicle control apparatus that supplies and consumes electric power regenerated by the electric motor during deceleration, an operating condition detecting means for detecting an operating condition of the vehicle, and an engine based on the detected operating condition A fuel cut determination means for determining the fuel cut condition, a fuel cut determination delay means for delaying a determination result of the fuel cut determination means by a predetermined delay time, and a fuel cut determination delayed by the fuel cut determination delay means. Engine control means for cutting fuel supplied to the engine in response The predetermined delay time of the fuel cut determination delay means is set by delay time calculation means for calculating the delay time according to the allowable input / output power of the battery. It is characterized by that.
[0010]
First 2 According to the present invention, in the first invention, the predetermined delay time of the fuel cut determination delay means is set by delay time calculation means for calculating the delay time according to an allowable output power of a battery, and the regenerative power by the motor Prior to the occurrence of this, the fuel is cut and the power consumption by the generator is performed.
[0011]
First 3 The invention of the 2 In the invention, the motor continues the motor output corresponding to the power generated by the generator until the motor output is stabilized at a predetermined value after the delay time by the delay time calculation means has elapsed.
[0012]
【The invention's effect】
Therefore, in the first invention, the fuel supply to the engine is maintained until the predetermined delay time elapses after the fuel cut permission condition is satisfied, and the engine torque gradually decreases during this period. If the engine torque has sufficiently decreased, excessive power is input to and output from the battery even if a timing shift occurs between the stepped generator control and the motor control that are performed in accordance with the fuel cut. It is possible to prevent the battery from deteriorating.
[0013]
Also, Since the fuel cut delay time is set according to the allowable input / output power of the battery, the battery input / output power generated when the fuel cut is performed can be suppressed within an allowable range (a range that does not cause deterioration of the battery).
[0014]
First 2 In this invention, the fuel cut delay time is set according to the allowable output power of the battery, and the fuel cut and the power consumption by the generator are performed prior to the generation of the regenerative power by the motor. It can be set short, and the fuel consumption improvement by fuel cut can be obtained to the maximum.
[0015]
First 3 In this invention, the control for matching the power generation (consumption) power of the generator and the power consumption (power generation) of the motor is temporarily interrupted only when the fuel cut is performed, and the fluctuation range of the motor output (load) is suppressed to drive the vehicle. Can be improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0017]
FIG. 1 is a system configuration diagram of a vehicle to which the present invention is applied. In this vehicle, an electric power train 5 that functions as a continuously variable transmission is connected to the engine 1 instead of a conventional mechanical transmission. The electric power train 5 includes a first rotating electric machine (hereinafter referred to as a generator) 2 that is mainly used as a generator and a second rotating electric machine (hereinafter referred to as an electric motor) 4 that is mainly used as an electric motor. . The rotor shaft of the generator 2 is connected to the crankshaft of the engine 1, and the rotor shaft (hereinafter referred to as output shaft) 6 of the electric motor 4 is connected to a drive shaft (rotary shaft to which drive wheels are attached) via a reduction gear.
[0018]
The generator 2 and the motor 4 are AC machines such as permanent magnet AC synchronous motors, and are connected to an inverter 8 respectively. The rotational speeds of the generator 2 and the electric motor 4 are controlled according to the drive frequency of the inverter 8, and the drive frequency ratio of the inverter 8 becomes the rotational speed ratio (transmission ratio) of the input / output shaft of the electric power train 5. A battery 9 (such as a lithium battery or a nickel metal hydride battery) is further connected to the inverter 8.
[0019]
A clutch 3 is interposed between the generator 2 and the electric motor 4, and when the clutch 3 is engaged, the engine 1 and the output shaft 6 are directly connected to drive the output shaft 6 directly by the engine 1. Can do. The clutch 3 is engaged when, for example, the generator rotational speed of the electric power train 5 and the motor rotational speed coincide with each other, and the loss in the generator 2 and the electric motor 4 can be suppressed to improve the fuel efficiency of the vehicle.
[0020]
The electric power train 5 includes a generator rotation speed sensor 24 that detects a rotor rotation speed (hereinafter referred to as “generator rotation speed”) Ni of the generator 2 and a rotor rotation speed (hereinafter referred to as “motor rotation speed”) No. of the electric motor 4. An electric motor rotational speed sensor 21 for detecting the above is attached.
[0021]
On the other hand, an electronically controlled throttle device 14 is provided in the intake passage of the engine 1, and the accelerator operation of the driver is realized so that the target engine torque set according to the generated power required for the throttle opening is realized. Is controlled independently. In addition, the engine 1 is provided with an air flow meter 13 for detecting the intake air amount and a crank angle sensor 23 for detecting the crank angle.
[0022]
The integrated control unit (GCU) 10 basically obtains the driving force requested by the driver based on the accelerator operation amount detected by the accelerator operation amount sensor 22 and controls the transmission so that the required driving force is realized. Torque control of the electric motor 4 is performed via the unit (TCU) 12. Further, the rotational speed control of the generator 2 via the transmission control unit 12 and the engine 1 via the engine control unit (ECU) 11 so that the generated power corresponding to the drive output (power consumption) of the electric motor 4 can be obtained. The torque control is also performed.
[0023]
Further, the integrated control unit 10 regenerates electric power by causing the motor 4 to function as a generator during vehicle deceleration (fuel cut), and further consumes this regenerative power by powering the generator 2 as an electric motor. Balance the power balance even during deceleration.
[0024]
FIG. 2 is a block diagram showing the contents of vehicle control performed by the integrated control unit 10.
[0025]
This will be described. In block B1, the target driving force tFdO [N] is calculated based on the accelerator pedal operation amount APO [deg] and the vehicle speed VSP [km / h]. Specifically, the target driving force tFdO is calculated with reference to a predetermined target driving force map according to the accelerator pedal operation amount APO and the vehicle speed VSP. The driving force map is set according to the state in which fuel is supplied to the engine. The accelerator pedal operation amount APO is detected by the accelerator operation amount sensor 22, and the vehicle speed VSP is calculated by multiplying the rotation speed No [rpm] of the motor 4 detected by the motor rotation speed 21 sensor by a constant G1. The constant G1 is calculated by G1 = 2 × π × r × 60 / (R × 1000) where r is the radius of the driving wheel of the vehicle and R is the reduction ratio from the output shaft of the motor 4 to the driving wheel shaft. Is the value to be
[0026]
In block B2, the target motor output tPo00 [W] is calculated by multiplying the target driving force tFdO [N] by the vehicle speed VSP [m / s]. The vehicle speed VSP is calculated by multiplying the motor rotation speed No [rpm] detected by the motor rotation speed sensor 21 by a constant G2. The constant G2 is a value calculated by G1 = 2 × π × r / (R × 60).
[0027]
In block B3, the target motor output tPo00 [W] is filtered. This filtering process is performed in order to reduce the apparent control response speed of the electric motor 4.
[0028]
In block B4, the target driving force tFd_d [N] at the time of fuel cut is calculated based on the vehicle speed VSP [km / h]. Specifically, the target driving force tFd_d at the time of fuel cut is calculated by referring to the fuel-cut target driving force table according to the vehicle speed VSP. The target driving force tFd_d at the time of fuel cut is set to a negative value (indicating that the vehicle drives the electric motor 4) except for the extremely low vehicle speed range.
[0029]
In block B5, the target motor regenerative power tPo_d [W] at the time of fuel cut is calculated by multiplying the target driving force tFd_d [N] at the time of fuel cut by the vehicle speed VSP [m / s]. The target motor regenerative power tPo_d at the time of fuel cut represents the target value of the regenerative output of the motor 4 (= the kinetic energy of the vehicle consumed per unit time by the regenerative drive of the motor 4).
[0030]
In block B6, the target motor output is selected based on the fuel cut determination flag fFCUT from the fuel cut determination means 30, and when the flag fFCUT is zero (non-fuel cut), the filtered target motor output tPoO [W ] And the flag fFCUT is 1 (fuel cut), the target motor regenerative power tPo_d [W] at the time of fuel cut is selected.
[0031]
The fuel cut determination flag fFCUT is set by the fuel cut determination means 30 comprising the block diagram shown in FIG. In block B30, the charging-side delay time DLFCUTc [ms] is calculated based on the filtered target motor output tPoO [W] and the battery allowable input power BPc [W]. The charging side delay time DLFCUTc is such that the maximum power difference on the battery charging side (input side) generated at that time even when there is a deviation between the generator control and the motor control before and after the fuel cut is performed is the allowable battery input power BPc. It is calculated as the delay time as follows. The battery allowable input power BPc is a value calculated according to the battery temperature and the state of charge, and indicates the upper limit of input power that does not cause battery deterioration.
[0032]
In block B31, the discharge-side delay time DLFCUTd [ms] is calculated based on the filtered target motor output tPoO [W] and the battery allowable output power BPd [W]. The discharge-side delay time DLFCUTd is such that the maximum power difference on the battery discharge side (output side) that occurs at the time even when a deviation occurs between the generator control and the motor control before and after the fuel cut is performed is the battery allowable output power BPd. It is calculated as the delay time as follows. The battery allowable output power BPd is a value calculated according to the battery temperature and the state of charge, and indicates the upper limit of output power that does not cause battery deterioration.
[0033]
In the block B32, the larger one of the charge side delay time DLFCUTc and the discharge side delay time DLFCUTd is selected as the final delay time DLFCUT [ms] and output to the block B36.
[0034]
In block B33, it is determined with hysteresis whether or not the accelerator pedal is fully closed (accelerator pedal operation amount APO is substantially zero). In block B34, whether or not the vehicle speed is equal to or higher than the predetermined vehicle speed is determined with hysteresis. judge. Block B 35 Performs AND processing on both determination results, and outputs a fuel cut condition satisfaction signal to block B36 and block B37 when the output is 1.
[0035]
In block B36, the fuel cut condition satisfaction signal input by the delay time DLFCUT [ms] selected in block B32 is delayed, and in block B37, an AND process is performed between the output of block B35 and the output of block B36 to generate fuel. The value of the cut determination flag fFCUT is determined.
[0036]
In block B7, the target motor output selected in block B6 is divided by the motor rotation speed No [rad / s] to calculate the target motor torque tTo [Nm]. The motor rotation speed No [rad / s] is calculated by multiplying the motor rotation speed No [rpm] detected by the motor rotation speed sensor 21 by a constant G3 (= 2 × π / 60).
[0037]
The calculated target motor torque tTo is sent to the transmission control unit 12, and the torque of the motor 4 is controlled based on the target motor torque tTo. In particular, when the target motor torque tTo is a negative value, the transmission control unit 12 controls the regenerative torque of the motor 4.
[0038]
In block B8, the motor efficiency EFFm is calculated based on the motor rotation speed No [rpm] and the target motor torque tTo [Nm]. In block B9, the target motor output tPo00 [W] is divided by the motor efficiency EFFm, and the power consumption tPg [W] of the motor 4 is calculated. When the fuel cut is not performed, direct power distribution is performed in which the electric power consumed by the electric motor 4 is generated by the electric generator 2 without excess or deficiency, so that the electric motor power consumption tPg corresponds to the target generated electric power of the electric generator 2.
[0039]
In block B10, the generator efficiency EFFg is calculated based on the generator rotational speed Ni [rpm] and the engine torque. The generator rotational speed Ni is detected by the generator rotational speed sensor 24. Further, as the value of the engine torque, a value obtained by performing a predetermined delay process in the block B11 on the output of the block B22 (target engine torque tTe [Nm]), which will be described later, or the output (engine brake torque Te_d [ Nm]) is selected in block B12.
[0040]
In block B12, the output of block B11 is selected when the fuel cut determination flag fFCUT is zero (non-fuel cut), and the output of block B19 is selected when the flag fFCUT is 1 (fuel cut).
[0041]
In block B13, the motor consumption power tPg [W] is divided by the generator efficiency EFFg to calculate the target engine output tPe [W]. In block B14, the target engine output tPe [W] is divided by the vehicle speed VSP [m / s] to calculate the second target driving force tFd [N].
[0042]
In block B15, the target generator rotational speed tNiO [rpm] is calculated based on the second target driving force tFd [N] and the vehicle speed VSP [km / h]. Specifically, the target generator rotational speed tNiO is calculated by referring to a predetermined output distribution map according to the second target driving force tFd and the vehicle speed VSP.
[0043]
Here, the output distribution map is, for example, as shown in FIG. This can be determined, for example, based on the following concept. 5 and 6 show the basic concept of a method for determining the operating point of the engine according to the vehicle speed and the accelerator operation amount (method for determining output distribution).
[0044]
When the driver depresses the accelerator pedal in an attempt to accelerate, the output of the vehicle, that is, the output of the electric motor 4 increases accordingly (FIG. 5). When the same output is generated from the engine 1, the power distribution during powering (combination of engine and generator torque and rotational speed) is traced so as to trace the operating point where the fuel efficiency is the best for each output. Can be determined (FIG. 6).
[0045]
On the other hand, when the accelerator is fully closed, the engine torque is determined according to the engine rotational speed. In this case, there is no degree of freedom in the output distribution setting method, and the engine torque and the engine rotational speed are determined according to the output of the motor 4. The combination is uniquely determined.
[0046]
FIG. 7 shows an example of the target power generation output and the target generator rotation speed determined in accordance with the motor output thus determined. Since there is only one best fuel consumption line and accelerator fully closed torque line, if the output distribution is determined in consideration of only the fuel consumption, the target generator rotational speed is determined from the target power generation output using the relationship shown in FIG. be able to.
[0047]
However, even if the outputs are equal, if the sound vibration performance deteriorates if the engine torque is set too high in a region where the vehicle speed is low, there is a demand to increase the rotation to some extent in such a region. Therefore, in this example, the output distribution is a map corresponding to the vehicle speed and the driving force as a configuration that gives a degree of freedom of setting according to the vehicle speed so as to meet such a demand. FIG. 4 is obtained by simply replacing the relationship of FIG. 7 with a map.
[0048]
As described above, the output distribution map as shown in FIG. 4 is set, and the output distribution map is also set according to the fuel cut state or the fuel supply state of the engine.
[0049]
Returning to FIG. 2, in block B16, the target generator rotational speed tNiO [rpm] is filtered. This filtering process is performed to reduce the apparent control response speed of the generator 2. This filtering process is the same as the filtering process of block B3.
[0050]
In block B17, the target driving force tFd_d [N] at the time of fuel cut is multiplied by the motor efficiency EFFm, and the generated power (regenerative power) tPg_d [W] of the motor 4 at the time of fuel cut is calculated. At the time of fuel cut, the electric power regenerated by the electric motor 4 is consumed by the generator 2 without excess or deficiency, so tPg_d is also the target generator power consumption at the time of fuel cut.
[0051]
In block B18, the target generator power consumption tPg_d [W] is multiplied by the generator efficiency EFFg to calculate the generator output tPe_d [W] at the time of fuel cut. Since the generator 2 rotates the engine 1 at the time of fuel cut, the generator output tPe_d at the time of fuel cut represents the target engine brake output at the time of fuel cut.
[0052]
In block B19, the engine brake torque Te_d [Nm] at the time of fuel cut is calculated based on the generator rotational speed Ni [rpm] (= engine rotational speed). Specifically, the engine brake torque Te_d at the time of fuel cut is set with reference to the engine brake torque table according to the generator rotational speed Ni, and the engine brake torque Te_d at the time of fuel cut is set to a negative value. A negative value of the engine brake torque Te_d at the time of fuel cut indicates that the generator 2 drives the engine 1.
[0053]
In block B20, the target engine brake output tPe_d [W] at the time of fuel cut is divided by the engine brake torque Te_d [Nm] at the time of fuel cut to calculate the target generator rotational speed tNi_d [rad / s] at the time of fuel cut. .
[0054]
In block B21, the final target generator rotational speed tNif is selected based on the fuel cut determination flag fFCUT. When the flag fFCUT is zero (non-fuel cut), the target generator rotational speed tNi [rpm] after the filtering process is used, and when the flag fFCUT is 1 (fuel cut), the constant G4 (= 1 / G3) is used. The converted target generator rotation speed tNi_d [rpm] at the time of fuel cut is selected as the final target motor rotation speed tNif.
[0055]
The final target generator rotational speed tNif is sent to the transmission control unit 12, and the rotational speed of the generator 2 is controlled based on the tNif.
[0056]
On the other hand, in block B22, the target engine output tPe [W] is divided by the generator rotational speed Ni [rad / s] to calculate the target engine torque tTe [Nm]. The generator rotational speed Ni [rad / s] is calculated by multiplying the generator rotational speed Ni [rpm] detected by the generator rotational speed sensor 24 by a constant G3.
[0057]
The calculated target engine torque tTe is sent to the engine control unit 11, and the torque of the engine 1 is controlled based on the target engine torque tTe. Specifically, the throttle opening of the electronically controlled throttle device 14 is controlled, and the engine intake air amount is adjusted. However, when the fuel cut determination flag fFCUT is 1, the fuel supply to the engine 1 is cut, and in this case, the torque control of the engine 1 is interrupted.
[0058]
Since the engine torque at the time of non-fuel cut generally follows a predetermined delay with respect to the throttle opening control, the filter processing of the block B3 and the block B16 is a response delay of such an engine. Is provided to synchronize the control of the motor and generator. On the other hand, since there is no delay as described above in the engine brake torque at the time of fuel cut, the target motor output and the target generator rotational speed at the time of fuel cut are not filtered.
[0059]
The operation at the time of fuel cut by releasing the depression of the accelerator pedal at time t1 during traveling will be described with reference to the time chart of FIG. FIG. 8 shows changes in the accelerator pedal operation amount APO (A), changes in the output (= power consumption) of the motor 4 (B), changes in the generated power (= engine output) of the generator 2 and the engine torque. (C) and the transition of the battery input / output power is shown in (D), respectively. In FIG. 8B, a value greater than zero indicates a power running state of the motor 4, and a value smaller than zero indicates a power generation (regeneration) state. In FIG. 8C, a value greater than zero indicates a power generation state of the generator 2. Smaller than zero indicates a power running state. In FIG. 8D, a value greater than zero indicates a discharged state of the battery 9, and a value smaller than zero indicates a charged state.
[0060]
At t0 to t1, when the accelerator pedal is depressed, the motor 4 is driven and controlled according to the filtered target motor output tPoO [W] obtained by the blocks B1 to B3 (FIG. 8 (B)). The generator 2 is controlled based on the target generated power tPg obtained by the block B9, and the rotational speed is controlled by the target generator rotational speed tNi after the filtering process by the block B16. The engine 1 is output based on the target engine output tPe by the block B13. Is controlled by the engine control unit 11 (FIG. 8C).
[0061]
When the accelerator pedal operation amount APO decreases to zero at time t1, the block B33 of the fuel cut determination means 30 shown in FIG. 3 determines whether or not the accelerator pedal operation amount APO is fully closed with a hysteresis, and a block B34 When the vehicle is traveling at the vehicle speed VSP, the fuel cut condition establishment signal is output to the block B36 and the block B37 by the block B35.
[0062]
In the block B36, the charge side delay time DLFCUTc by the block B30 and the discharge side delay time DFLCUTd by the block B31 are delayed by the time set by the delay time DLFCUT selected high in the block B32, and a fuel cut condition establishment signal is output to the block B37 To do. Therefore, the change in the value of the fuel cut determination flag fFCUT output from the block B37 from zero to 1 is delayed from the time point t1 to the time point t3 when the delay time DLFCUT elapses.
[0063]
As shown in FIG. 8B, the target motor output tPo00 by the blocks B1 and B2 shifts to the power generation side from the time point t1, and the target motor output tPoO after the filtering is performed according to the time constant of the filter by the block B3. It decreases toward the output tPo00, changes from the power running state to the power generation (regeneration) state at time t2, and thereafter gradually approaches the target motor output tPo00.
[0064]
Further, the above change in the target motor output tPo00 shifts the motor target generated power tPg by the block B9 to the power running side from the time t1 as shown in FIG. 8C, and the actual generated power E of the generator 2 is changed to the block B16. According to the time constant of the filter according to the above, it decreases toward the target generator output tPg, changes from the power generation state driven by the engine 1 to the power running state that drives the engine 1 at the time t2, and thereafter toward the target generator output tPg. Asymptotically.
[0065]
The target generated power tPg is shifted to the power running side by shifting the target engine torque tPe obtained by the block B13 from the driving side to the driven side (brake side), and via the block B22 and the engine control unit 11. The actual engine torque F obtained from the engine 1 decreases toward the target engine torque tPe, changes from the driving side to the driven side (brake side) near the time point t2, and thereafter gradually approaches the target engine torque tPe. .
[0066]
After this time t2, the electric motor 4 is driven by the output shaft 6 and is in a power generation (regeneration) state, and the generated electric power is driven by driving the generator 2 to drive the engine 1 by the generator 2. The regenerative control (engine brake) state is reached.
[0067]
When the delay time DLFCUT set in the block B36 of the fuel cut determination means 30 elapses (time point t3), the fuel cut condition flag fFCUT is set to 1 from the block B37, and the engine control unit 11 cuts the fuel to the engine 1. The block B6 is switched, and the electric motor 4 is controlled to generate the target motor regenerative power tPo_d at the time of fuel cut obtained by the blocks B4 and B5.
[0068]
Further, the change of the fuel cut condition flag fFCUT to 1 switches the block B21 so that the target power consumption tPg_d at the time of the fuel cut output by the block B9 based on the target motor regenerative power tPo_d at the time of the fuel cut becomes the block. The generator 2 is controlled via B18 and B20.
[0069]
At this time point t3, by delaying the output of the fuel cut condition flag fFCUT to 1 by the delay time DLFCUT, the filtered target motor output tPoO and the target generator power output from the blocks B3 and B16 are At t2, the power generation state and the power running (consumption) state have already shifted, and are sufficiently close to the target motor regenerative power tPo_d and the target generator power consumption tPg_d at the time of fuel cut, respectively.
[0070]
For this reason, when the control timing of the electric motor 4 and the generator 2 is shifted, for example, when the rise of the target motor regenerative power tPo_d at the time of fuel cut of the electric motor 4 is earlier than the rise of the target power consumption tPg_d of the generator 2, The power that cannot be consumed by the generator 2 is instantaneously charged to the battery 9 as shown by the dotted line in FIG. 8D, but does not exceed the battery allowable input power BPc.
[0071]
When the rise of the target motor regenerative power tPo_d at the time of fuel cut of the motor 4 is delayed from the rise of the target power consumption tPg_d of the generator 2, the power generated by the motor 4 covers the consumption of the generator 2. Although it is not completely discharged from the battery 9 to the generator 2, it is instantaneous as indicated by the solid line in FIG. 8D and does not exceed the battery allowable output power BPd.
[0072]
After this time t3, the generator 2 and the motor 4 are controlled by the target power consumption tPg_d at the time of fuel cut and the target motor regenerative power tPo_d at the time of fuel cut, and the vehicle is regeneratively braked.
[0073]
In the above description, the example in which the delay time of the fuel cut condition flag fFCUT is made variable according to the allowable input / output powers BPc and BPd of the battery 9 is described. However, the present invention is not limited to this. The delay time may be set. In this case, even when the battery allowable input power BPd and the battery allowable output power BPd are minimum, values are set such that the battery input / output power is within the allowable range, and the fuel consumption is somewhat deteriorated.
[0074]
In this embodiment, the fuel supply to the engine is maintained until the predetermined delay time by the block B36 elapses after the fuel cut permission condition by the blocks B33 to B35 is satisfied, and the engine torque F gradually increases during this period. To drop. If the engine torque F is sufficiently reduced, excessive power is input to and output from the battery 9 even if a timing shift occurs between the stepped generator control and the motor control performed in accordance with the fuel cut execution. It is possible to prevent the battery 9 from deteriorating.
[0075]
Further, since the fuel cut delay time is set according to the allowable input / output powers BPc and BPd of the battery 9 by the blocks B30 to B32, the input / output power of the battery 9 generated when the fuel cut is performed is set within the allowable range (battery 9 Within a range that does not cause degradation of
[0076]
FIGS. 9 to 11 are block diagrams of the integrated control unit 10 showing the second embodiment of the present invention. In the first embodiment, after a delay time that varies depending on the state of the battery, the motor, the generator, and While the engine is shifted to the fuel cut control state all at once, in the second embodiment, the control when the motor is not fuel-cut is changed to the control that generates the target motor regenerative power when the fuel is cut. Is switched after a fixed delay time.
[0077]
Therefore, in FIG. 9, the fuel cut determination flag fFCUT1 for the block B6 and the fuel cut determination flag fFCUT2 for the blocks B12, B21 and the engine control unit 11 are independent of each other. The fuel cut determination flag fFCUT1 is the block shown in FIG. The fuel cut determination flag fFCUT2 is delayed according to the block diagram shown in FIG. 10 and 11 constitute the fuel cut determination means 30A.
[0078]
The delay of the fuel cut determination flag fFCUT1 in FIG. 10 is performed by the block B43 having a fixed delay time DLFCUT [ms]. In block B40, it is determined whether or not the accelerator pedal is fully closed (accelerator pedal operation amount APO is substantially zero) with hysteresis. In block B41, whether or not the vehicle speed VSP is equal to or higher than the predetermined vehicle speed is determined. In the block B42, both determination results are ANDed. When the output is 1, the fact that the fuel cut condition is satisfied is output to the block B43 and the block B44.
[0079]
In block B43, the output of the fuel cut condition input by a fixed delay time DLFCUT [ms] is delayed. In block B44, the output of block B41 and the output of block B43 are ANDed to perform fuel cut. The value of the flag fFCUT1 is determined.
[0080]
The fuel cut determination flag fFCUT2 in FIG. 11 is calculated in block B50 based on the filtered target motor output tPoO [W] and the battery allowable output power BPd [W], and the second delay time DLFCUT2 [ms] is calculated. And set as a delay time in the block B54. The second delay time DLFCUT2 is such that the maximum power difference on the battery discharge side (output side) that occurs at the time when a deviation occurs between the generator control and the motor control before and after the fuel cut is performed is the battery allowable output power BPd. It is calculated as the delay time as follows. The battery allowable output power BPd is a value calculated according to the temperature and the state of charge of the battery 9 and indicates the upper limit of the output power that does not cause the battery 9 to deteriorate.
[0081]
Accordingly, whether or not the accelerator pedal is fully closed (accelerator pedal operation amount APO is substantially zero) is determined with hysteresis in block B51, and whether or not the vehicle speed VSP is equal to or higher than the predetermined vehicle speed is determined in block B52. In step B53, both determination results are ANDed. When the output is 1, the fact that the fuel cut condition is satisfied is output to block B54 and block B55.
[0082]
Then, in block B54, the output of the fuel cut condition input by the second delay time DLFCUT2 [ms] set in block B50 is delayed, and in block B55, AND processing of the output of block B53 and the output of block B54 is performed. To determine the value of the fuel cut flag fFCUT2.
[0083]
The operation of the second embodiment will be described with reference to the time chart of FIG. 12A to 12D are the same as those in FIG.
[0084]
When the accelerator pedal is released at time t1 and the accelerator pedal operation amount APO is reduced to zero, the target motor output tPoO after the filter processing of the motor 4 gradually approaches the target motor output (power generation state) tPo00 before the filter passage of the block B3. Block B6 is switched at time t3 when the fuel cut determination flag fFCUT1 is output as 1 after both target motor outputs (tPoO, tPo00) coincide with each other, after decreasing along the time constant curve and in a power generation (regeneration) state. The motor 4 is controlled so as to generate the target motor regenerative power tPo_d at the time of fuel cut obtained by the blocks B4 and B5 (FIG. 12B).
[0085]
On the other hand, the generator 2 shifts the motor target generated power tPg by the block B9 to the power running side from the time t1 as shown in FIG. 12C, and the actual generated power E of the generator 2 is filtered by the block B16. It decreases toward the target generator output tPg according to the constant.
[0086]
The engine 1 shifts the target engine torque tPe obtained by the block B13 from the drive side to the driven side (brake side) by shifting the target generated power tPg of the block B9 to the power running side. The actual engine torque F obtained from the engine 1 via the control unit 11 decreases toward the target engine torque tPe.
[0087]
When the delay time DLFCUT2 set in the block B54 elapses, the fuel cut determination flag fFCUT2 is output to 1 from the block B55, the engine control unit 11 cuts the fuel to the engine 1, the block B21 is switched, and the fuel The generator 2 is controlled via the blocks B18 and B20 so that the target power consumption tPg_d at the time of fuel cut output by the block B9 is based on the target motor regenerative power tPo_d at the time of cut.
[0088]
Due to the timing difference between the delay times DLFCUT1 and DLFCUT2 in FIGS. 12B and 12C, the discharge output based on the regeneration delay by the motor 4 from the battery 9 to the generator 2 is generated between the time points t2 and t3. This is done as shown in FIG.
[0089]
This discharge output power does not exceed the allowable output power BPd of the battery 9 because the delay time DLFCUT2 is set as a function of the battery allowable output power BPd and the filtered target motor output tPoO in the block B50. .
[0090]
The output difference between the target motor output tPo00 (= tPoO) at the time of non-fuel cut of the motor 4 and the target motor regenerative output tPo_d at the time of fuel cut is set as a fixed value that does not increase or decrease depending on the state of the battery. Therefore, the level difference of the driving (braking) force change that occurs when the fuel is cut is constant, and the vehicle driver is not discomforted.
[0091]
In this embodiment, it is possible to improve the drivability of the vehicle by interrupting the control for matching the generated (consumed) power of the generator 2 with the consumed (generated) power of the electric motor 4 only when the fuel cut is executed.
[0092]
That is, the delay time DLFCUT2 is set in order to set the fuel cut delay time DLFCUT2 according to the allowable output power BPd of the battery 9 and cause the fuel cut and power consumption by the generator 2 prior to the generation of regenerative power by the motor 4. Can be set as short as possible, and fuel efficiency improvement by fuel cut can be obtained to the maximum.
[0093]
In addition, the control for matching the power generation (consumption) power of the generator 2 and the power consumption (power generation) of the motor 4 is suspended only during the fuel cut to suppress the fluctuation range of the motor output (load) and drive the vehicle. Can be improved.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a vehicle to which the present invention is applied.
FIG. 2 is a block diagram showing control contents of an integrated control unit.
FIG. 3 is a block diagram showing details of fuel cut determination processing.
FIG. 4 is a graph showing an example of an output distribution map.
FIG. 5 is a diagram for explaining a method for determining output distribution;
FIG. 6 is a view for explaining a method for determining output distribution.
FIG. 7 is a table showing a relationship between a target power generation amount and a target generator rotation speed.
FIG. 8 is a time for explaining the operation by the accelerator pedal operation amount transition (A), the motor output transition (B), the generator power generation transition (C), and the battery input / output power transition (D) at the time of fuel cut. chart.
FIG. 9 is a block diagram showing a second embodiment.
FIG. 10 is a block diagram showing a part of the fuel cut determination means.
FIG. 11 is a block diagram showing another part of the fuel cut determination means.
FIG. 12 shows changes in accelerator pedal operation amount (A), changes in output of an electric motor (B), changes in generated power of a generator (C), and changes in input / output power of a battery (D) during fuel cut according to the second embodiment. The time chart explaining operation | movement by.
[Explanation of symbols]
1 engine
2 Generator
4 Electric motor
9 Battery integrated control unit (GCU)
10 Engine control unit (ECU)
11 Transmission Control Unit (TCU)
12 Electronically controlled throttle device
14 Motor rotation speed sensor
21 Accelerator operation amount sensor
22 Crank angle sensor
23 Generator rotation speed sensor

Claims (3)

An engine, a generator connected to the output shaft of the engine, an electric motor connected to a drive shaft of the vehicle, and a battery connected to the generator and the electric motor; In the hybrid vehicle control device for supplying and consuming the generated power to the generator,
Driving condition detecting means for detecting the driving condition of the vehicle;
Fuel cut determination means for determining a fuel cut condition of the engine based on the detected operating condition;
Fuel cut determination delay means for delaying the determination result of the fuel cut determination means by a predetermined delay time;
Engine control means for cutting fuel to be supplied to the engine in response to the fuel cut judgment delayed by the fuel cut judgment delay means ,
The control apparatus for a hybrid vehicle, wherein the predetermined delay time of the fuel cut determination delay means is set by delay time calculation means for calculating the delay time according to an allowable input / output power of a battery .   The predetermined delay time of the fuel cut determination delay means is set by delay time calculation means for calculating the delay time according to the allowable output power of the battery, and fuel cut and power generation prior to generation of regenerative power by the electric motor. The hybrid vehicle control device according to claim 1, wherein power consumption by the machine is performed. 3. The motor according to claim 2 , wherein the motor continues the motor output corresponding to the power generated by the generator until the motor output is stabilized at a predetermined value after the delay time by the delay time calculation means has elapsed. Hybrid vehicle control device.

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