JP2008024178A - Driving force controller for hybrid car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase responsiveness to a target driving force in a hybrid car equipped with an engine and motor/generator as a power source. <P>SOLUTION: An integrated controller 20 for controlling the driving force of a hybrid car is provided with: a correction torque calculation part 300 for estimating the influence of the disturbance torque of a power train equipped with an engine 1 and a motor/generator 5, and for calculating correction torque Tc for correcting target driving torque tTw according to the influence; and a filter processing part 100 for removing or reducing frequency components which are a predetermined value or more from a change gear output revolution speed No as the basis of the calculation of the target driving torque tTw. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to driving force control of a hybrid vehicle that combines an engine that is an internal combustion engine and a motor that is a rotating electrical machine as a power source, and relates to the followability of the actual driving torque with respect to the target driving torque, in other words, the motor torque and the engine. The present invention relates to a technology for improving torque response.

The present applicant has already proposed the invention described in Patent Document 1 as an invention for controlling the driving force of a hybrid vehicle.
In the technique described in Patent Document 1, the engine and the motor are drive-coupled by a two-degree-of-freedom power transmission mechanism (such as a planetary gear mechanism), and the speed is changed by controlling the difference between the engine speed and the motor speed. In a hybrid vehicle with a powertrain system that changes the ratio,
A device for controlling the driving force of this hybrid vehicle
Target driving force generating means for generating target driving power and target driving torque based on the accelerator opening and the vehicle speed;
Target engine rotation speed calculation means for calculating the target engine rotation speed from the target drive power;
A target for setting the target motor torque and the target engine torque so that an excess or deficiency of the actual drive torque with respect to the target drive torque does not occur and a deviation of the actual engine rotation speed with respect to the target engine rotation speed is reduced. Torque calculating means.
According to the control device described in Patent Document 1, since the torque consumed by the speed change operation can be calculated even during the speed change operation in which the speed ratio is changed, Thus, the target drive torque can be realized with high precision, and the acceleration feeling desired by the driver can be obtained.
JP 2004-248410 A

  By the way, the hybrid vehicle is affected by disturbance torque input from outside the power train to the power train system in addition to the situation of the power train system in which the shifting operation consumes motor torque and engine torque. In addition, frequency components are mixed when generating the target drive power and target drive torque described above, and frequency components are mixed when setting the target motor torque and the target engine torque based on the target drive power and the target drive torque. There are circumstances of the control system. For this reason, if the disturbance torque and the frequency component are so large that they cannot be ignored for the control system, or if the frequency component is in a band that is not preferable for control, the actual motor torque and the engine torque are set to the target motor torque described above. In addition, the present applicant has found that there is a concern that the responsiveness deteriorates when following the target engine torque.

  An object of the present invention is to propose a control device that solves the above-described concern about deterioration of responsiveness in driving force control of a hybrid vehicle.

To this end, the hybrid vehicle driving force control apparatus according to the present invention is provided in a power train having an engine and a motor / generator as a power source according to claim 1, and is adapted to the traveling state and the driving state. In a driving force control device for a hybrid vehicle that calculates a target driving torque and controls the driving force of the engine and the motor / generator so as to follow the target driving torque.
A correction torque calculating means for calculating the correction torque for estimating the influence of the disturbance torque of the power train and correcting the target drive torque according to the influence;
A frequency component greater than or equal to a predetermined value is removed or reduced from at least one of the correction torque calculated by the correction torque calculation means, the target drive torque, and the information on the driving state and the driving state that are the basis for calculating the target driving torque. It is characterized by comprising high frequency removing means.

  According to the driving force control apparatus for a hybrid vehicle of the present invention, since the target driving torque correction means eliminates the influence of disturbance torque, the actual motor torque and the engine torque follow the target motor torque and the target engine torque satisfactorily. Responsiveness is improved. In addition, since the high frequency component which is not preferable for control away from the frequency characteristic of the target drive torque is removed, the response is improved.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 shows a power train of a front engine / rear wheel drive hybrid vehicle having a hybrid drive device to which the transmission state switching control device of the present invention can be applied, where 1 is an engine and 2 is a drive wheel (rear wheel). is there.
In the power train of the hybrid vehicle shown in FIG. 1, the automatic transmission 3 is arranged in tandem at the rear of the engine 1 in the longitudinal direction of the vehicle in the same manner as a normal rear wheel drive vehicle, and the engine 1 (crankshaft 1a) is rotated. A motor / generator 5 is provided in combination with the shaft 4 that transmits to the input shaft 3a of the automatic transmission 3.

The motor / generator 5 acts as a motor or acts as a generator (generator), and is disposed between the engine 1 and the automatic transmission 3.
More specifically, a first clutch 6 is inserted between the motor / generator 5 and the engine 1 and, more specifically, between the shaft 4 and the engine crankshaft 1a, and the engine 1 and the motor / generator 5 are disconnected by the first clutch 6. Join as possible.
Here, the transmission torque capacity of the first clutch 6 can be changed continuously or stepwise. For example, the transmission torque capacity can be changed by continuously controlling the clutch hydraulic oil flow rate and the clutch hydraulic pressure with a proportional solenoid. It consists of a simple wet multi-plate clutch.

More specifically, a second clutch 7 is inserted between the motor / generator 5 and the automatic transmission 3 and more specifically between the shaft 4 and the transmission input shaft 3a. The second clutch 7 causes the motor / generator 5 and the automatic transmission to be inserted. 3 are separably connected.
Similarly to the first clutch 6, the second clutch 7 can change the transmission torque capacity continuously or stepwise. For example, the proportional hydraulic solenoid can continuously control the clutch hydraulic fluid flow rate and the clutch hydraulic pressure to transmit torque. It consists of a wet multi-plate clutch whose capacity can be changed.

The automatic transmission 3 is the same as that described in pages C-9 to C-22 on the "Skyline New Car (CV35) Manual" issued by Nissan Motor Co., Ltd. in January 2003. By selectively engaging or releasing a shift friction element (such as a clutch or a brake), a transmission path (shift stage) is determined by a combination of engagement and release of these shift friction elements.
Therefore, the automatic transmission 3 shifts the rotation from the input shaft 3a at a gear ratio corresponding to the selected shift speed and outputs it to the output shaft 3b.
This output rotation is distributed and transmitted to the left and right rear wheels 2 as drive wheels by the differential gear device 8, and is used for traveling of the vehicle.
However, it goes without saying that the automatic transmission 3 is not limited to the stepped type as described above, and may be a continuously variable transmission.

  In the power train of FIG. 1 including the automatic transmission 3 described above, when the electric travel (EV) mode used at low load / low vehicle speed including when starting from a stopped state is required, the first clutch 6 Is released, the second clutch 7 is engaged, and the automatic transmission 3 is in a power transmission state.

When the motor / generator 5 is driven in this state, only the output rotation from the motor / generator 5 reaches the transmission input shaft 3a, and the automatic transmission 3 changes the rotation to the input shaft 3a to the selected shift speed. The speed is changed according to the speed and output from the transmission output shaft 3b.
Then, the rotation from the transmission output shaft 3b reaches the rear wheel 2 via the differential gear device 8, and the vehicle can be electrically driven (EV traveling) only by the motor / generator 5.

When hybrid driving (HEV driving) mode used when driving at high speeds, during heavy loads, or when the amount of power that can be taken out by the battery is low, both the first clutch 6 and the second clutch 7 are engaged, The automatic transmission 3 is brought into a power transmission state.
In this state, the output rotation from the engine 1, or both the output rotation from the engine 1 and the output rotation from the motor / generator 5 reach the transmission input shaft 3a, and the automatic transmission 3 is connected to the input shaft 3a. Is rotated according to the currently selected shift speed and output from the transmission output shaft 3b.
The rotation from the transmission output shaft 3b then reaches the rear wheel 2 via the differential gear device 8, and the vehicle can be hybrid-driven (HEV-driven) by both the engine 1 and the motor / generator 5.

  In such HEV traveling, when the engine 1 is operated with the optimal fuel efficiency, if the energy becomes surplus, the surplus energy is converted into electric power by operating the motor / generator 5 as a generator by this surplus energy, and this generated power is converted into electric power. By accumulating power to be used for driving the motor of the motor / generator 5, the fuel consumption of the engine 1 can be improved.

In FIG. 1, the second clutch 7 that detachably couples the motor / generator 5 and the drive wheel 2 is interposed between the motor / generator 5 and the automatic transmission 3,
As shown in FIG. 2, even if the second clutch 7 is interposed between the automatic transmission 3 and the differential gear device 8, the same function can be achieved.

In addition, in FIG. 1 and FIG. 2, a dedicated second clutch 7 is added before or after the automatic transmission 3,
Instead, as the second clutch 7, as shown in FIG. 3, a shift friction element for selecting a forward shift stage or a shift friction element for selecting a reverse shift stage existing in the automatic transmission 3 may be used.

The engine 1, the motor / generator 5, the first clutch 6, and the second clutch 7 that constitute the power train of the hybrid vehicle shown in FIGS. 1 to 3 are controlled by a system as shown in FIG.
In the following description, it is assumed that the power train is as shown in FIG. 3 (existing speed change friction element in the automatic transmission 3 as the second clutch 7).

  The control system of FIG. 4 includes an integrated controller 20 that integrally controls the operating point of the power train. The operating point of the power train includes the target engine torque tTe, the target motor / generator torque tTm, and the target transmission of the first clutch 6. It is defined by the torque capacity tTc1 (first clutch command pressure tPc1) and the target transmission torque capacity tTc2 (second clutch command pressure tPc2) of the second clutch 7.

In order to determine the operating point of the power train, the integrated controller 20
A signal from the engine rotation sensor 11 for detecting the engine speed Ne;
A signal from the motor / generator rotation sensor 12 for detecting the motor / generator rotation speed Nm;
A signal from the input rotation sensor 13 for detecting the transmission input rotation speed Ni,
A signal from the output rotation sensor 14 that detects the transmission output rotation speed No,
A signal from an accelerator opening sensor 15 for detecting an accelerator pedal depression amount (accelerator opening APO) representing a required load state of the engine 1;
A signal from a storage state sensor 16 that detects a storage state SOC (carryable power) of the battery 9 that stores power for the motor / generator 5 is input.

  Among the sensors described above, the engine rotation sensor 11, the motor / generator rotation sensor 12, the input rotation sensor 13, and the output rotation sensor 14 can be arranged as shown in FIGS.

The integrated controller 20 determines the driving force of the vehicle desired by the driver from the accelerator opening APO relating to the driving state, the battery storage state SOC, and the transmission output speed No (vehicle speed VSP) relating to the driving state among the above input information. Is selected, the target engine torque tTe, the target motor / generator torque tTm, the target first clutch transmission torque capacity tTc1 (first clutch command pressure tPc1), and the target 2 Clutch transmission torque capacity tTc2 (second clutch command pressure tPc2) is calculated.
The target engine torque tTe is supplied to the engine controller 21, and the target motor / generator torque tTm is supplied to the motor / generator controller 22.

The engine controller 21 controls the engine 1 so that the engine torque Te becomes the target engine torque tTe.
The motor / generator controller 22 controls the motor / generator 5 via the battery 9 and the inverter 10 so that the torque Tm (or the rotational speed Nm) of the motor / generator 5 becomes the target motor / generator torque tTm.
The integrated controller 20 generates solenoid currents corresponding to the target first clutch transmission torque capacity tTc1 (first clutch command pressure tPc1) and the target second clutch transmission torque capacity tTc2 (second clutch command pressure tPc2). 2 Supply to the hydraulic control solenoid (not shown) of the clutch 7 so that the transmission torque capacity Tc1 (first clutch pressure Pc1) of the first clutch 6 matches the target transmission torque capacity tTc1 (first clutch command pressure tPc1) Further, the first clutch 6 and the second clutch 7 are set such that the transmission torque capacity Tc2 (second clutch pressure Pc2) of the second clutch 7 matches the target second clutch transmission torque capacity tTc2 (second clutch command pressure tPc2). The fastening force is controlled individually.

  Further, the integrated controller 20 selects the above-described operation mode (EV mode, HEV mode), and targets engine torque tTe, target motor / generator torque tTm, target first clutch transmission torque capacity tTc1 (first clutch command pressure tPc1), In addition, control for calculating the target second clutch transmission torque capacity tTc2 (second clutch command pressure tPc2) is performed.

FIG. 5 is a block diagram showing the above-described control in the integrated controller 20.
Referring to FIG. 5, the filter processing unit 100 uses a high cut filter (also referred to as a low pass filter) to obtain a transmission output rotational speed No corresponding to the vehicle speed VSP from a predetermined value included in the signal. A process of reducing or removing the frequency, that is, the high frequency component is performed, and the processed signal Nof is output to the target driving force calculation unit 200.

  The target driving force calculation unit 200 calculates the target driving torque tTw of the driving wheel 2 with reference to the map shown in FIG. 6 based on the signal of the processed transmission output speed Nof and the signal of the accelerator opening APO, The calculated target drive torque tTw is output to the correction torque calculator 300 and the target value generator 400.

  The correction torque calculation unit 300 receives a signal indicating the transmission output speed No corresponding to the vehicle speed VSP and the signal indicating the target drive torque tTw. The correction torque calculation unit 300 calculates a torque Tc for correcting the target drive torque tTw based on the transmission output rotation speed No, and inputs the correction torque Tc to the target value generation unit 400. The process for obtaining the correction torque Tc will be described later.

The target value generation unit 400 determines the target engine torque tTe and the target motor / generator torque tTm based on the correction torque Tc, the target drive torque tTw, the engine torque Te, and the speed ratio Gr of the automatic transmission 3 described above. Compute and output the results of these computations. Between these values Tc, tTw, tTe, tTm, and Gr, the relationship shown in the following equation is established.
Tc + tTw = (tTe + tTm) × Gr (1)
Gr is a gear ratio of the automatic transmission 3 as described above, and is calculated from, for example, a shift position.

  Here, when calculating the engine torque Te, the general controller 20 determines between the throttle opening of an engine (not shown), the reference engine speed obtained from the vehicle speed VSP and the overall transmission ratio of the vehicle transmission system, and the actual engine speed Ne. It can be obtained from the engine rotation deviation.

  FIG. 7 is a flowchart showing the control shown in FIG. The integrated controller 20 executes the control shown in FIG. 7 at regular intervals of 10 ms, for example. Describing along the flowchart shown in FIG. 7, in the first step S1, the detected accelerator opening APO, the detected transmission output rotational speed No, and the obtained engine torque Te are read. Instead of reading the transmission output rotational speed No, the wheel speed of the drive wheel 2 may be detected, and a value obtained by multiplying the detected value by the fixed gear ratio of the differential gear device 8 may be read.

In the next step S2, a processed transmission output rotational speed Nof in which vibration in the high frequency region is reduced or eliminated is calculated from the read transmission output rotational speed No. For example, the low-pass filter process shown in the following equation is performed on the transmission output rotational speed No.

  In the next step S3, the target drive torque tTw is determined by referring to the map shown in FIG. 6 based on the processed transmission output rotational speed Nof calculated in step S2 and the accelerator opening APO read in step S1. Ask. This processed transmission output rotational speed Nof corresponds to the vehicle speed VSP.

In the next step S4, a correction torque is calculated. For example, the disturbance observer control means shown in FIG. 8 is used as the correction torque calculation means.
Here, the control shown in FIG. 8 will be explained. Jo is (FIGS. 1 to 3) the inertia of the drive system shown in FIG. 3, J is an estimated value of the inertia of the drive system, τ is an observer time constant, and Tdo is actually The inevitable disturbance torque generated, Td is the estimated disturbance torque, Kd is the correction gain obtained according to the estimated disturbance torque Td, and Tc is the correction torque.
The correction gain Kd is obtained based on the estimated disturbance torque Td with reference to the characteristic diagram shown in FIG. If the absolute value of the estimated disturbance torque Td is equal to or less than the threshold value Td1, the correction gain Kd is a constant value Kd1. If the absolute value of the estimated disturbance torque Td is not less than the threshold value Td1 and not more than the threshold value Td2, the correction gain Kd becomes larger than Kd1 as it becomes larger than the threshold value Td1. If the absolute value of the estimated disturbance torque Td is greater than or equal to the threshold value Td2, the correction gain Kd is a constant value Kd2. Thus, the correction gain Kd is not a constant value Kd2, but has a characteristic that takes a small value in a region where the absolute value of the estimated disturbance torque Td is small. Considering that there is some error in bit rate, it is intended to be a protection and adjustment item that prevents the control system from failing due to the calculated disturbance torque.

Returning to FIG. In the next step s5, the following equation is used based on the engine torque Te read in step S1, the target drive torque tTw obtained in step S3, and the correction torque Tc obtained in step S4. A target engine torque tTe and a target motor / generator torque tTm are generated.
tTe = tTw / Gr (3)
tTm = (tTe−Te) + Tc / Gr (4)
When the target engine torque tTe and the target motor / generator torque tTm are calculated in step S5, the present control is exited.

By the way, according to the above-described embodiment, the transmission output rotational speed No corresponding to the traveling state (vehicle speed VSP) and the equivalent of the driving state are provided in the power train including the engine 1 and the motor / generator 5 as power sources. The target drive torque tTw corresponding to the accelerator opening APO to be calculated is calculated, and the torque Tm of the motor / generator 5 is set so as to follow the target drive torque tTw, that is, the torque Te of the engine 1 follows the target engine torque tTe. In the hybrid vehicle driving force control device that controls to follow the generator torque tTm,
A correction torque calculator 300 that estimates the influence of disturbance torque on the power train and calculates a correction torque Tc for correcting the target drive torque tTw according to the influence;
A filter processing unit 100 for removing a frequency component in a high frequency band equal to or higher than a predetermined value from the information value No of the running state serving as a basis for calculating the target drive torque tTw;
The case where the engine controller 21 is controlled so as to follow the target engine torque tTe and the case where the motor / generator controller 22 is controlled so as to follow the target motor / generator torque tTm are reliably eliminated. In addition, it is possible to reliably eliminate the influence of high frequency components. According to the present embodiment, since the influence of the low frequency component and the influence of the low frequency component can be individually excluded, it can be compensated that the target acceleration cannot be obtained due to disturbance or the like, and the actual drive with respect to the target drive torque tTw The response of the torque is improved, and the acceleration feeling desired by the driver can be obtained.

In other words, the disturbance torque that is unavoidable in the characteristics of the power train is vibration in the low frequency region. Therefore, by providing means (correction torque calculation unit 300) for correcting the target drive torque tTw so as to eliminate this vibration, the power train The responsiveness can be effectively improved.
Further, since the noise generated in the control system shown in FIG. 5 is a vibration in a high and low frequency region, the response as the control system is effectively improved by providing means (filter processing unit 100) for reducing or removing this vibration. Can be made.

  In this embodiment, as shown in FIG. 5, a filter processing unit 100 is provided on the upstream side of the arrow in the block diagram, and the information value of the running state serving as a basis for calculating the target drive torque tTw, that is, the transmission output rotational speed No. The high frequency component is removed or reduced from the above. Although not shown in the drawings, the high frequency component may be removed or reduced from the target driving torque tTw, or the high frequency component may be removed or reduced from the correction torque Tc. If it is acceptable in terms of cost, high frequency components may be removed or reduced from a plurality of No, tTw, and Tc.

In this embodiment, as shown in FIGS. 1 to 3, the engine 1 and the motor / generator 5 are drivingly coupled, and the motor / generator 5 and the driving wheel 2 are drivingly coupled.
In the hybrid vehicle having such a configuration, the response to the target drive torque tTw is improved, and the acceleration feeling desired by the driver can be obtained.

Further, in this embodiment, as shown in FIGS. 1 to 3, the automatic transmission 3 is inserted in the drive transmission path on the drive wheel 2 side from the motor / generator 5.
In the hybrid vehicle constituting the drive system as shown in FIGS. 1 to 3, the response delay of the engine torque can be compensated by adding the difference between the estimated engine torque and the target engine torque to the target motor torque. Therefore, the response of the actual engine torque Te and the response of the motor / generator torque Tm to the target drive torque tTw are improved, and the acceleration feeling desired by the driver can be obtained.

  The above description is merely an example of the present invention, and the present invention can be variously modified without departing from the spirit of the present invention.

1 is a schematic plan view showing a power train of a hybrid vehicle to which a driving force control device of the present invention can be applied. It is a schematic plan view which shows the power train of the other hybrid vehicle which can apply the driving force control apparatus of this invention. It is a schematic plan view which shows the power train of the further another hybrid vehicle which can apply the driving force control apparatus of this invention. FIG. 4 is a skeleton diagram showing an automatic transmission in the power train shown in FIGS. FIG. 5 is a block diagram showing functions of the integrated controller shown in FIG. It is a map referred in order to obtain | require target drive torque. It is a flowchart showing execution of the control system shown in FIG. 5 by the integrated controller shown in FIG. It is a block diagram of the disturbance observer which shows the calculation of the correction torque Tc in the control system. FIG. 9 is a characteristic diagram for obtaining a correction gain of the disturbance observer illustrated in FIG. 8.

Explanation of symbols

1 Engine 2 Drive wheel (rear wheel)
3 Automatic transmission 4 Transmission shaft 5 Motor / generator 6 First clutch 7 Second clutch 8 Differential gear device 9 Battery
10 Inverter
11 Engine rotation sensor
12 Motor / generator rotation sensor
13 Transmission input rotation sensor
14 Transmission output rotation sensor
15 Accelerator position sensor
16 Battery charge sensor
20 Integrated controller
21 Engine controller
22 Motor / generator controller

Claims (3)

Provided in a power train having an engine and a motor / generator as a power source, calculate a target driving torque according to the running state and the driving state, and set the driving force of the engine and the motor / generator so as to follow the target driving torque. In the driving force control device for a hybrid vehicle to be controlled,
A correction torque calculating means for calculating the correction torque for estimating the influence of the disturbance torque of the power train and correcting the target drive torque according to the influence;
A frequency component greater than or equal to a predetermined value is removed or reduced from at least one of the correction torque calculated by the correction torque calculation means, the target drive torque, and the information on the driving state and the driving state that are the basis for calculating the target driving torque. A driving force control device for a hybrid vehicle, characterized by comprising high-frequency removing means. In the hybrid vehicle driving force control device according to claim 1,
A driving force control apparatus for a hybrid vehicle, wherein the engine and the motor / generator are drivingly coupled, and the motor / generator and driving wheels are drivingly coupled. The driving force control apparatus for a hybrid vehicle according to claim 2,
The driving force control apparatus for a hybrid vehicle, wherein the power train includes a transmission in a drive transmission path closer to the driving wheel than the motor / generator.

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