JP3097734B2 - Drive control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize desired operation of a controller and improve control on each engine in a hybrid system made up of rotating force by an internal combustion engine and a motor, by detecting or estimating torque having an influence on the engine and compensating the torque previously. SOLUTION: Torque Tin from a hybrid engine is applied to a second motor 1202 through a differential gear 1203. Then, a torque T2 as a desired output torque Tout can be obtained when a difference between a torque command (command value T2) and the torque Tin applied to the second motor 1202 in the hybrid engine is instructed by a controller 220.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power source control device for a vehicle, and more particularly to a hybrid in which an internal combustion engine and a motor act on each other to rotate, and are mounted as a power source for driving wheels of an automobile. The present invention relates to a vehicle drive control device of the type described above.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine (hereinafter referred to as an engine)
Various types of hybrid vehicles have been proposed which are equipped with a motor and a motor, and are driven together or selectively to be used as a power source of the vehicle (for example, Japanese Patent Application Laid-Open No. Hei 7-135701). In the system in this publication, an engine and a first
, A second motor having two axes, a first differential gear, a second differential gear, and driving tires.

[0003] The torque of the engine and the first motor is applied to the second motor through a first differential gear. Hereinafter, this combination of the engine, the first motor, and the operating gear is referred to as a hybrid engine. The second motor is characterized in that the motor shaft protrudes in both directions, and the second differential gear distributes torque to the left and right wheels to drive the vehicle. In this hybrid system, the driving force of the vehicle is obtained by the hybrid engine and the second motor.

[0004]

However, in the above-described drive control device, the following inconvenience occurs because the torque of the hybrid engine and the torque of the second motor interact with each other. In this drive control device, the driver requests the output torque to the vehicle using the accelerator pedal. When the second motor torque is controlled in accordance with the torque request value, the torque applied from the hybrid engine to the second motor is reduced. 2 is added to the output torque of the second motor, and a torque greater than the command value is applied to the vehicle. Further, when the required torque is distributed to the hybrid engine and the second motor, a change in mechanical torque of the hybrid engine is slower than a change in electric torque of the second motor. The problem that cannot be obtained arises.

[0005] Further, in the rotational speed feedback control conventionally used, the torque which becomes a disturbance is mainly friction and the like.
This friction torque is smaller than the torque generated by the second motor to be controlled, and this disturbance torque does not pose any practical problem in performing feedback control. However, in the present drive control device, the magnitude of the torque applied from the hybrid engine to the second motor has a magnitude that drives the vehicle. Since this value is the same level as the second motor torque to be controlled, a state in which a large disturbance torque is equivalently applied to the rotation speed control system will result. When such a large disturbance torque is present, if the feedback control gain of the controller is increased to improve the followability of the rotation speed control of the second motor, the control system becomes unstable due to the influence of the disturbance torque. However, if the gain is reduced in order to stabilize the control system, the error between the rotational speed command value and the actual value increases, causing a problem that controllability deteriorates.

As described above, in the above-described vehicle drive device,
Since the amount of torque applied from the hybrid engine to the second motor is large, a phenomenon occurs in which the controllability of the second motor deteriorates. Therefore, in the present invention, in a hybrid system having a hybrid engine and a second motor,
An object of the present invention is to improve the control performance of a hybrid system by compensating for torques that affect each other in order to improve individual controllability.

[0007]

According to the present invention, in order to achieve the above object, a hybrid engine including an internal combustion engine and a first motor and an output shaft of the hybrid engine are provided. A drive control device connected to an input shaft of a second motor having two input / output shafts, and an output shaft of the second motor connected to drive wheels via a differential gear; A torque command value is input or calculated, a torque value applied from the hybrid engine to the input shaft of the second motor is obtained, and based on this value, the torque command value of the second motor is corrected in a feedforward manner. By doing so, the controllability of the second motor can be improved.

According to a second aspect of the present invention, the torque command value of the second motor is determined based on a signal based on an operation amount of an accelerator pedal. When the command value is corrected by the control described in claim 1 for the torque applied from the hybrid engine to the second motor, the torque specified by the accelerator pedal is applied to the vehicle. Feeling is improved.

According to a third aspect of the present invention, a torque command value of the second motor is determined based on a command value and a detection value of an output shaft speed of the second motor. Correcting the torque applied from the hybrid engine to the second motor by the method described in claim 1 with respect to this command value improves the responsiveness and stability when controlling the rotation speed of the second motor. I do.

According to a fourth aspect of the present invention, a torque command value of the second motor is determined based on a command value and a detection value of an output shaft rotation position of the second motor. Correcting the torque applied from the hybrid engine to the second motor by the method described in claim 1 with respect to this command value improves responsiveness and stability when controlling the rotational position of the second motor. I do.

According to a fifth aspect of the present invention, the torque input from the hybrid engine to the input shaft of the second motor is determined from an input value such as a current command value of the second motor and an output value such as a change in rotation speed. The estimation is performed using a disturbance observer according to the related art.
This estimation predicts the output value of the motor from the input value of the motor and its transfer function, and the difference between the predicted output value and the actually measured value is due to the torque applied externally to the system. It is a technology to be considered. According to this method, the torque applied to the second motor can be estimated, and the torque command value can be corrected based on the estimated value.

According to a sixth aspect of the present invention, there is provided a method for calculating a torque value applied to an input shaft of a second motor. The engine torque and the torque of the first motor are estimated respectively, and the applied torque is calculated using the specifications of the differential gear. In this case, if the control device for the engine and the first motor measures or estimates the output torque of each, it is also possible to substitute the values.

[0013]

Next, a first embodiment of the present invention will be described. Since the power source of this embodiment is composed of an engine and a motor, the vehicle is a hybrid vehicle. Further, the motor described here means a rotating electric machine that performs both functions of driving and power generation.

FIG. 1 shows the overall configuration of the hybrid vehicle in the first embodiment. In FIG. 1, reference numeral 1204 denotes an engine, which is a known in-line four-cylinder engine using gasoline as a fuel in the present embodiment. The first differential gear 1203 is a known planetary gear having three axes, each of which is connected to the engine 1204, the first motor 1201, and the second motor 1202. The first motor 1201 is
It is a known permanent magnet type three-phase synchronous motor, which is vector-controlled by an inverter not described here. The second motor 1202 is a known permanent magnet type three-phase synchronous motor, and as shown in FIG. 2, a shaft 601 connected to a rotor 604 having N poles and S poles of a permanent magnet.
Reference numeral 602 denotes a structure extending in both directions in the axial direction of the rotor 604, and the current of the winding 603 is vector-controlled by an inverter not described herein.

A rotor position detector (not shown), for example, a known resolver is used for the first motor 1201 and the second motor 1202, and outputs a rotor position signal to be used for the above-described vector control. Can be The second differential gear 1205 connects the shaft 602 of the second motor 1202 with the left and right wheels 1206. Here, the first motor 1
201 controls the rotation speed of the shaft connected to the first motor 1201 so that even if the rotation speed of the second motor 1202, that is, the vehicle speed changes, the engine 1 is controlled independently of this change.
An operation of controlling the number of rotations of 204 to a desired value is performed. First
The control method of the motor 1201 is omitted.

The second motor 1202 is a second motor 1
The shaft torque of 202 is controlled. This torque command value is set so that the torque commanded by the driver using the accelerator is output to the shaft 602 of the motor 1202 at 202 via the controller at 220 during normal running of the hybrid vehicle. In this case, as shown in FIG. 11, even if an attempt is made to control the second motor 1202 with the torque command value T2, the torque T
is applied, the output torque To of the actual vehicle
ut does not reach the desired value T2.

Therefore, since the torque Tin is applied to the second motor 1202 from the hybrid engine via the first differential gear 1203, as shown in FIG. 3, a torque command (command value T2) by the accelerator is used. And the second motor 1
202, the torque Tin applied from the hybrid engine
And the controller 220 instructs the difference from the above, the torque T2 can be obtained as a desired output torque Tout for the vehicle.

The control at this time will be described with reference to the flowchart shown in FIG. In step 501,
After inputting the torque command value T2, the torque Tin acting from the hybrid engine is input to the controller 220 in step 502. Then, in step 503,
The command torque correction unit corrects the torque command value T2 by subtracting the torque Tin acting from the hybrid engine.
Here, the torque command value of the second motor is obtained from the accelerator command, but it is also possible to determine the torque command value from the states of the accelerator command and the brake command.

As an application of this embodiment, there is an application in a case where the engine torque output Tin of the hybrid engine is stopped during running by fuel cut or the like. At the time of fuel cut, a sudden loss of torque is felt. However, by compensating for this decrease in torque with the torque of the second motor 1202, it is possible to reduce the loss of torque. further,
Engine 1 with first motor 1201 of hybrid engine
It is also applicable when starting 204. In this case, by compensating the generated torque of the second motor 1202 according to the torque Tin input to the second motor 1202 from the hybrid engine, the second motor 1202
Of the output torque can be suppressed. With this control, for example, the vehicle does not move even when the engine is started when the vehicle is stopped, and no torque shock is generated when the engine is started when the vehicle is propelled.

The torque value input from the hybrid engine to the second motor 1202 is obtained by estimating the engine torque from the operating state of the engine (rotational speed, throttle opening, air amount, fuel injection amount, etc.) The torque of the first motor 1201 is estimated from the command torque of the first motor 1201 or the current / voltage of the first motor 1201, and is calculated from the engine torque and the torque of the first motor 1201 in consideration of the gear ratio of the operating gear 1. I do. In this calculation, when the control device of the engine and the first motor 1201 estimates or measures the respective torques, it is also possible to calculate based on the values. As another method for obtaining the torque input to the second motor 1202, the input shaft torque can be directly measured by a torque sensor or the like. As described above, since the torque value input to the second motor 1202 is known, it is possible to compensate the torque command value of the second motor 1202 based on this value.

By the above means, the output torque can be controlled according to the accelerator operation amount, and the operation feeling of the hybrid vehicle can be improved. Also, the above control method can be applied when the torque command value of the second motor is given from another control device. In the control system of the hybrid system, first, a torque value applied from the hybrid engine to the input shaft of the second motor 1202 is taken. This torque value may be a torque measurement value using a torque sensor or the like, or the first motor 12
01, the input / output torque of the engine 1204 (actually measured or estimated) and the torque estimated value applied to the second motor 1202 from the specifications of the first differential gear 1203.

The torque command value of the second motor 1202 is
A value obtained by converting an accelerator command into a torque command value, or a value determined by feedback control such as PI and PID based on deviations of the number of rotations and the rotational position is used. The present invention is characterized in that the determined torque command value is corrected in a feedforward manner based on the torque value applied to the second motor 1202 from the hybrid engine.

By this feedforward control, the second
In the control of the motor 1202, it is possible to correct in advance the amount of torque applied to the second motor 1202 from the hybrid engine which has been conventionally treated as a disturbance. As a result, the change in the torque input from the hybrid engine does not act as a disturbance, and the second motor 1
The controllability of the hybrid system 202 can be improved, and thus the controllability of the entire hybrid system can be improved.

Next, a second embodiment of the present invention will be described. The overall configuration of the hybrid vehicle of the second embodiment is the same as that of the first embodiment.
Since the content is the same as that of FIG. 1 in the embodiment, a control portion different from the embodiment 1 will be described below. The purpose of controlling the second motor 1202 in this embodiment is to control the number of rotations or the rotation angle of the second motor 1202 to a desired value. For example, in FIG. 1, when the engine 1204 is started by the first motor 1201, the rotation speed of the second motor 1202 is controlled to 0 so that the vehicle does not move, or the rotation position is fixed to an arbitrary value. It is used for such control. In addition, when the vehicle is driven at the command speed, the controllability is improved.

First, a case where the number of rotations of the second motor 1202 is controlled will be described with reference to FIG. The torque Tin input from the hybrid engine to the second motor 1202 in 201 is the second motor 1
In the rotation speed control system 202, it acts as a disturbance and causes deterioration of the rotation speed controllability. That is, when torque is input from the hybrid engine to the second motor 1202, the rotation speed of the second motor 1202 increases, and conversely, when the torque is absorbed, the rotation speed decreases. In the related art, a feedback control system for the rotation speed is configured to control the rotation speed to a desired value. However, when the input torque component from the outside is large, the disturbance torque cannot be compensated for only by feedback. In other words, increasing the feedback gain makes the system easier to oscillate,
When the feedback gain is reduced, the error between the command value of the rotational speed and the actual value increases. Therefore, in the present invention,
Focusing on the fact that the input torque to the second motor 1202 can be estimated or measured as shown in the first embodiment, a means for improving the controllability of the rotational speed by feed-forward compensating this torque in advance is provided. FIG. 6 shows a flowchart of this control. First, in step 101, a rotation speed command value w2 is input, and then in step 102, the actual value of the rotation speed is measured. Then, in step 103, the torque value Tin input from the hybrid engine to the second motor 1202 is fetched,
Next, in step 104, the torque command value of the second motor 1202 is calculated by PI or PID control based on the difference between the rotation speed command value and the actually measured value, and the second command is calculated from this value.
Of the motor 1202 is subtracted from the torque applied from the hybrid engine.

Here, an engine start method using the control of the present invention will be described. First, rotation speed feedback control is performed by the second motor 1202 so that the rotation speed of the shaft becomes zero. Then, in this state, the engine is started using the first motor as a starter.
Then, the vehicle does not move, and the starting operation can be stably performed.

In addition, the present method can be applied to the case where the vehicle speed is controlled to a desired value by automatic driving of the vehicle or the like, and the output of the second motor 1202 is always maintained even when the engine of the hybrid engine is started or stopped. The shaft torque can be kept constant, and good controllability can be obtained. Also, at the time of the rotation angle control, similarly to the rotation speed control, the torque input from another engine to the motor 1202 is compensated in advance, so that the rotation angle controllability can be improved. FIG. 7 shows a control configuration of the present invention at the time of rotation angle control, and FIG. 8 shows a flowchart. The difference between the rotation speed control and the rotation angle control is as follows.
Since the control target is only a change based on a change from the rotation speed w of the second motor 1202 to the rotation angle θ, a detailed description is omitted.

Next, a third embodiment of the present invention will be described. If the torque input from the hybrid engine cannot be estimated as in the first and second embodiments, the torque control system calculates the disturbance torque applied to the input shaft of the second motor 1202 as shown in FIG. It is also possible to compensate using the observer. The observer estimates a torque to be a disturbance from a transfer function indicating the relationship between the torque command value of the second motor 1202, the actual rotation angle of the output shaft, and the input / output value. Here, the torque of the second motor 1202, the command value, and the actual rotation angle were selected for the input of the observer. However, since the purpose of this means is to estimate the disturbance torque, the input of the second motor 1202 It is also possible to use other input and transfer functions, such as estimating disturbance torque using the current of 1202, the actual rotation speed or the actual rotation angle, and the transfer function indicating the relationship between the current and the rotation speed or the rotation angle. is there.

According to this method, the torque applied from the hybrid engine to the second motor 1202 can be estimated, and the controllability can be improved using the estimated value as in the first and second embodiments. In the above-described embodiment, another effect is a smooth start operation of the engine. When the engine 1204 is started by the first motor 1201 in a state where the vehicle is stopped, the torque applied to the second motor 1202 greatly changes before and after the start of the engine. Therefore, the second motor 12
It is necessary to control the torque 02, the number of rotations, or the rotation angle to prevent torque shock and erroneous starting. In this case the second
In order to control the rotation speed and rotation angle of the motor 1202 to desired values, the control method of the present invention is effective.

As another form of the start operation, the second operation
After starting the vehicle with the motor 1202, the engine may be started at a certain speed. In this case, the torque transmitted to the tires suddenly changes before and after the engine starts, causing an unpleasant shock or a sudden change in the number of revolutions of the vehicle. Patents can be used.

Further, when the engine is stopped during driving due to a fuel cut or the like, a sudden torque loss occurs.
It is also possible to prevent this feeling of torque loss by assisting the loss of engine torque with the second motor 1202. In addition, when the vehicle speed is controlled to a desired value, the controllability is improved by using the present control method.

In the above embodiment, the rotor position detector (not shown) is attached to the motor, but a signal from a rotation detector attached to the engine may be used. Further, in order to simplify the motor structure, it is possible to perform a known sensorless control of the synchronous motor without using the rotor position detector. Further, an induction motor or a reluctance motor can be used instead of the synchronous motor. Even when an induction motor or a reluctance motor is used, known sensorless control without using a rotor position detector or a rotation speed detector can be applied.

The internal combustion engine of the first embodiment has a series
Although a cylinder gasoline engine was used, the number of cylinders is irrelevant to the gist of the present invention. Further, it may be a diesel engine. In FIG. 1, the engine 1204 and the first motor 1201 are connected to the second motor 1202 via the first differential gear 1203. However, according to the present invention, the torque input to the second motor 1202 is The control amount of the second motor 1202 is corrected based on the value.
With respect to the configuration of the hybrid engine until the torque is input to the engine 02, for example, as shown in FIG.
04 and the motors 1202 and 1207 can be combined in series.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a hybrid vehicle according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram schematically showing a motor having two axes in FIG. 1;

FIG. 3 is a block diagram illustrating torque control of the first embodiment.

FIG. 4 is a flowchart illustrating a calculation of torque control according to the first embodiment.

FIG. 5 is a block diagram illustrating rotation speed control according to a second embodiment of the present invention.

FIG. 6 is a flowchart illustrating a calculation of a rotation speed control according to a second embodiment.

FIG. 7 is a block diagram illustrating rotation angle control.

FIG. 8 is a flowchart showing a calculation of rotation angle control.

FIG. 9 is a block diagram illustrating torque control using an observer according to a third embodiment of the present invention.

FIG. 10 is an overall configuration diagram showing another structure of the hybrid vehicle.

FIG. 11 is a block diagram showing a conventional torque control.

[Explanation of symbols]

201 Torque applied from hybrid system to second motor 202 Second motor 203 Controller 206 Observer 1201 First motor 1202 Second motor 1203 First differential gear 1204 Internal combustion engine 1205 Second differential gear 1206 Tire 1207 Motor

Claims (5)

(57) [Claims] 1. A hybrid engine comprising an internal combustion engine and a first motor, a second motor for increasing / decreasing an output shaft torque of the hybrid engine, and an output shaft of the second motor via a differential gear. A drive control device connected to the driving wheels, wherein the second motor is controlled based on a torque command value of the second motor, and is applied from the hybrid engine to an input shaft of the second motor. A torque calculating means for obtaining a torque as an applied torque calculation value; and a correcting means for subtracting and correcting the torque command value of the second motor by the applied torque calculation value, wherein the torque command value of the second motor is at least The said
2 based on the command value and the detected value of the output shaft speed of the motor
Drive control device, characterized in that the output. 2. A housing comprising an internal combustion engine and a first motor.
An hybrid engine and an output shaft torque of the hybrid engine
And the output of this second motor
A drive control device in which the power shaft is connected to the drive wheels via differential gears
In location, the second based on the torque command value of said second motor
Control the motor, and from the hybrid engine to the input shaft of the second motor.
Torque that determines the applied torque as the calculated applied torque
Torque calculating means, and calculating the applied torque by the torque command value of the second motor.
Correction means for performing a subtraction correction by a value, wherein a torque command value of the second motor is calculated based on at least a command value and a detection value of a rotational position of an output shaft of the second motor. Control device. 3. A housing comprising an internal combustion engine and a first motor.
An hybrid engine and an output shaft torque of the hybrid engine
And the output of this second motor
A drive control device in which the power shaft is connected to the drive wheels via differential gears
In location, the second based on the torque command value of said second motor
Control the motor, and from the hybrid engine to the input shaft of the second motor.
Torque that determines the applied torque as the calculated applied torque
Torque calculating means, and calculating the applied torque by the torque command value of the second motor.
Correction means for performing subtraction correction by a value corresponding to at least the output torque value or motor current of the second motor and the number of rotations or rotation of the output shaft from the hybrid engine to the second motor input shaft. A drive control device for estimating based on an angle. 4. A housing comprising an internal combustion engine and a first motor.
An hybrid engine and an output shaft torque of the hybrid engine
And the output of this second motor
A drive control device in which the power shaft is connected to the drive wheels via differential gears
In location, the second based on the torque command value of said second motor
Control the motor, and from the hybrid engine to the input shaft of the second motor.
Torque that determines the applied torque as the calculated applied torque
Torque calculating means, and calculating the applied torque by the torque command value of the second motor.
Correction means for performing subtraction correction by a value, wherein a torque applied from the hybrid engine to the second motor input shaft is calculated from at least an internal combustion engine torque in the hybrid engine and a torque of the first motor. Drive control device. 5. The drive control device according to claim 3, wherein the torque command value of the second motor is calculated based on at least a signal linked to an operation amount of an accelerator pedal.