JP3661413B2 - Torque fluctuation control device for hybrid motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the torque change of the engine with high accuracy in the torque change controller of a hybrid motor. SOLUTION: This hybrid motor, having the motor generator which gives the torque to the output shaft of the engine, is provided with a the following three in a hybrid motor which provides with a generation torque operation part 81, an inertia torque operation part 82, and a pulsation compensating torque operation part 83. The generation torque operation part 81 calculates generation torque according to the operating state of the engine. The inertia torque operation part 82 calculates inertia torque according to the engine speed. The pulsation compensating torque operation part 83 calculates pulsation compensating torque generated by the output shaft according to the output torque and the inertia torque of the engine. The drive or the power generation of the motor generator is controlled so that the pulsation compensating torque is obtained.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a torque fluctuation control device for a hybrid prime mover.
[0002]
[Prior art]
An engine that converts combustion pressure into output shaft torque via a piston that reciprocates in a cylinder causes periodic torque fluctuations in the output shaft. To suppress this torque fluctuation, an electric motor (motor generator) is used in the output shaft. There is known a hybrid prime mover in which torque fluctuations are suppressed by combining them.
[0003]
Conventionally, as this type of hybrid prime mover, for example, one disclosed in Japanese Patent Application Laid-Open No. Sho 62-255534 is provided with a strain gauge on the output shaft of the engine, and the torque fluctuation of the output shaft of the engine is controlled based on the output of the strain gauge. The drive or power generation of the electric motor is controlled so as to be suppressed.
[0004]
Japanese Patent Application Laid-Open No. 61-61929 calculates the generated torque based on the engine speed and the intake pressure, and causes the motor to generate a torque having a phase opposite to the calculated generated torque. ing.
[0005]
[Problems to be solved by the invention]
However, in such a conventional torque fluctuation control device for a hybrid prime mover, not only the cost of the product is increased by providing the strain gauge, but it takes time to process the output of the strain gauge, and the motor control The problem is that it is difficult to ensure responsiveness.
[0006]
Further, if the generated torque is calculated based on the engine rotation speed and the intake pressure, there is a problem that it is not possible to cope with the generated torque fluctuation caused by changes in the ignition timing of the engine and the air-fuel ratio.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a torque fluctuation control device for a hybrid prime mover capable of accurately suppressing engine torque fluctuation.
[0008]
[Means for Solving the Problems]
The present invention is applied to a hybrid prime mover including an engine that applies torque to an output shaft via a movable member that is driven by gas burned in a combustion chamber, and a motor generator that applies torque to the output shaft.
[0009]
Referring to FIG. 3, the invention according to claim 1 calculates an average generated torque calculating unit 81 that calculates a generated torque according to the operating state of the engine, and calculates an average inertia torque according to the rotational speed of the engine. And a pulsation compensation torque calculation unit 83 for calculating the pulsation compensation torque generated by the output shaft in accordance with the average generated torque and the average inertia torque of the engine, so that the pulsation compensation torque can be obtained. Control generator drive or power generation.
[0010]
The torque fluctuation control device for a hybrid prime mover described in claim 2 is applied to a four-cycle engine, and the generated torque calculation unit 81 calculates the average value of the generated torque every time the output shaft rotates 90 degrees.
[0011]
The torque fluctuation control device for a hybrid prime mover according to claim 3 is applied to a four-cycle engine, and the generated torque calculation unit 81 reaches the generated torque determination time every time the output shaft rotates 720 degrees, and is generated at the generated torque determination time. Update the operating conditions that are the data for calculating the torque.
[0012]
The torque fluctuation control device for a hybrid prime mover according to claim 4 is applied to a four-cycle engine, and the generated torque calculation unit 81 is based on an operation state detected before the output shaft rotates 180 degrees from the generated torque determination timing. Calculate the generated torque.
[0013]
The torque fluctuation control device for a hybrid motor according to claim 5 is applied to a four-cycle engine, and the generated torque calculation unit 81 sets the average value of the generated torque in the exhaust stroke to a constant value regardless of the operating conditions.
[0014]
In the torque fluctuation control device for a hybrid prime mover according to claim 6, the generated torque calculation unit 81 sets a characteristic obtained by normalizing the generated torque every time the output shaft rotates 180 degrees, and continuously calculates the generated torque.
[0015]
In the torque fluctuation control device for a hybrid prime mover according to claim 7, the generated torque calculation unit 81 normalizes the generated torque based on the maximum generated torque.
[0016]
In the torque fluctuation control device for a hybrid prime mover according to claim 8, the pulsation compensation torque calculator 81 sets the pulsation compensation torque to a value obtained by multiplying the sum of the output torque of the engine and the inertia torque by -1.
[0017]
In the torque fluctuation control device for a hybrid prime mover according to claim 9, the pulsation compensation torque calculation unit 81 limits the pulsation compensation torque to be equal to or less than the maximum output of the motor generator.
[0018]
In the torque fluctuation control device for a hybrid prime mover according to claim 10, pulsation compensation torque calculation unit 81 sets the maximum output of the motor generator according to the rotation speed and temperature of the motor generator.
In the torque fluctuation control device for a hybrid prime mover according to claim 11, the average inertia torque is calculated according to the rotational speed and the rotational phase of the engine.
[0019]
In the section of the means for solving the above-described problems for explaining the configuration of the present invention, the drawings of the embodiments of the invention are used for easy understanding of the present invention. It is not limited.
[0020]
【The invention's effect】
The torque fluctuation control device for a hybrid prime mover according to claim 1 can accurately suppress the torque fluctuation of the engine by calculating the pulsation compensation torque generated by the output shaft according to the average generated torque and the average inertia torque of the engine. .
[0021]
The torque fluctuation control apparatus for a hybrid prime mover according to any one of claims 2 to 5 can calculate fluctuations in torque generated by a four-cycle engine with sufficient accuracy.
[0022]
The torque fluctuation control device for a hybrid prime mover according to claim 6 or 7 can suppress engine torque fluctuation effectively without using a strain gauge or the like by normalizing the generated torque and continuously calculating the torque.
[0023]
The torque fluctuation control apparatus for a hybrid prime mover according to claim 8 can accurately suppress the engine torque fluctuation by setting the pulsation compensation torque to a value obtained by multiplying the sum of the engine output torque and the inertia torque by -1.
[0024]
The torque fluctuation control device for a hybrid prime mover according to claim 9 or 10 can avoid the pulsation compensation torque from exceeding the maximum output of the motor generator.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0026]
As shown in the engine system diagram of FIG. 1, the four-cycle spark ignition engine 1 converts combustion pressure into crankshaft torque via a piston 5 that reciprocates in a cylinder 6. That is, as each intake valve 2 is opened in the intake stroke in which the piston 5 descends, intake air (air mixture) is sucked into the cylinder 6 from the intake passage 3, and the air-fuel mixture is compressed by the piston 5 in the subsequent compression stroke. Then, the piston 5 is lowered in the expansion stroke that is ignited and burned by the spark plug 16, and the exhaust valve 7 is opened in the exhaust stroke in which the piston 5 rises. Each stroke is repeated continuously.
[0027]
An electric throttle valve 17 that throttles intake air is provided in the intake passage 3. The electric throttle valve 17 is driven to open and close via a step motor 18, and the opening degree is electronically controlled by the control unit 13. The control unit 13 controls the intake air amount in accordance with a target engine torque (shaft torque) signal obtained based on the accelerator opening and the like input from the general control unit. A diesel engine may be used in place of the spark ignition engine 1. In the case of a diesel engine, the engine torque can be controlled by adjusting the fuel injection amount, and an electric throttle valve is not necessary.
[0028]
An injector 4 for injecting fuel is provided in the intake passage 3. The control unit 13 includes an intake air amount Qa detected by the air flow meter 10, a throttle opening TVO detected by the throttle sensor 12, an engine speed Ne and an engine rotation phase detected by the crank angle sensor 11, ₂ A signal corresponding to the oxygen concentration in the exhaust gas detected by the sensor 19, the cooling water temperature Tw detected by the cooling water temperature sensor 21, etc. are input, and the fuel injection and stop from the injector 4 and the fuel injection amount are determined. While adjusting, the ignition timing of the spark plug 6 is adjusted.
[0029]
The engine 1 is mounted on a vehicle, and as shown in FIG. 2, the torque generated by the engine 1 is transmitted to drive wheels via an electromagnetic clutch 50, a continuously variable transmission 57, a differential device (not shown), and the like. An electromagnetic clutch 50 is interposed between the output shaft 52 coupled to the crankshaft of the engine 1 and the input shaft 51 of the continuously variable transmission 57. Instead of the electromagnetic clutch 50, a torque converter, a dry single plate clutch, a wet multi-plate clutch or the like may be provided.
[0030]
The continuously variable transmission (CVT) 57 includes a primary pulley 56 connected to the output side of the input shaft 51 as a variable pulley, and a secondary pulley 66 connected to a drive shaft. These variable pulleys are connected by a V belt 64. ing. The transmission ratio of the continuously variable transmission 57 is controlled by a hydraulic control valve 43 that responds to a command from the CVT control unit 41. In the continuously variable transmission 57, if the width of the V-shaped pulley groove of the primary pulley 56 is reduced, the contact radius of the V-belt 64 on the secondary pulley 66 side is increased, so that a large gear ratio can be obtained.
[0031]
The CVT control unit 41 includes a signal from a primary pulley rotation speed sensor 46 that detects the rotation speed Npri of the primary pulley 56 of the continuously variable transmission 57, a signal from the secondary pulley rotation speed sensor 47 that detects the rotation speed Nsec of the secondary pulley 66, The selected position from the inhibitor switch 48, the accelerator opening corresponding to the amount of depression of the accelerator pedal operated by the driver, the brake switch signal that is turned on when the brake pedal is depressed, and the vehicle speed signal are read and inputted from the general control unit 71. The gear ratio of the continuously variable transmission 57 is controlled according to the target gear ratio signal.
[0032]
A motor generator (M / G) 70 is coupled to the input shaft 51 of the continuously variable transmission 57 as an electric motor that applies torque to the output shaft 52. When the electromagnetic clutch 50 is engaged, the engine 1 and the motor generator 70 serve as a vehicle propulsion source, and when the electromagnetic clutch 50 is released, only the motor generator 70 serves as a vehicle propulsion source.
[0033]
The M / G control unit 71 controls the current of the motor generator 70 via the inverter 72 so that the torque generated by the motor generator 70 becomes the target motor generator torque input from the general control unit.
[0034]
The motor generator 70 is an AC machine such as a three-phase synchronous motor or a three-phase induction motor. The inverter 72 converts the DC charging power of the battery 73 into an AC current during powering operation and supplies it to the motor generator 70, and also during regenerative operation. The AC power generated by the motor generator 70 is converted into a direct current to charge the battery 73.
[0035]
By the way, in the case of the 4-cylinder engine 1, since the four pistons 5 reciprocate in each cylinder 6 and convert the combustion pressure into the torque of the engine output shaft 52, periodic torque fluctuations occur in the engine output shaft 52. .
[0036]
Further, the engine control unit 13 sets the air-fuel ratio of the air-fuel mixture sucked into each cylinder 6 according to the operating conditions to stoichiometric (theoretical air-fuel ratio), a lean air-fuel ratio larger than stoichiometric, and a rich air-fuel ratio smaller than stoichiometric. Next, the fuel injection amount of the injector 4 is controlled. Further, the engine control unit 13 stops the supply of fuel to some cylinders under predetermined cylinder deactivation conditions. That is, in the cylinder deactivation condition, the supply of fuel to the F / C cylinder is stopped and the fuel is supplied only to the combustion cylinder. The characteristic of torque fluctuation generated in the engine output shaft 52 also changes by performing the air-fuel ratio control or the cylinder deactivation control.
[0037]
Therefore, the M / G control unit 71 controls the driving or power generation of the motor generator 70 so as to suppress the torque fluctuation of the engine 1.
[0038]
As shown in FIG. 3, the M / G control unit 71 is detected by the generated torque calculation unit 81 that calculates the generated torque according to the operating state of the engine 1 sent from the engine control unit 13, and the crank angle sensor 11. An inertia torque calculator 82 that calculates an inertia torque according to the engine speed Ne and the phase of the engine rotation, and a motor generator 70 that suppresses torque fluctuations of the engine output shaft 52 according to the sum of the calculated generated torque and the inertia torque. And a pulsation compensation torque calculation unit 83 for calculating the pulsation compensation torque.
[0039]
The generated torque calculation unit 81 inputs the amount of intake air sent from the engine control unit 13, the air-fuel ratio of the air-fuel mixture, the ignition timing, the cylinder number, the fuel supply stop (F / C) signal, etc., and the generated torque for each cylinder. The calculation is performed and the calculated torques generated by all cylinders are added.
[0040]
The generated torque calculation unit 81 reaches the generated torque determination time every time the output shaft 52 rotates 720 degrees, and updates the operation condition that becomes data for calculating the generated torque at the generated torque determination time. The generated torque determination timing is a crank angle at which the piston reaches the bottom dead center in the intake stroke when the intake valve 2 is closed and the introduction of the intake air into the cylinder 6 is almost finished.
[0041]
The generated torque calculation unit 81 calculates the generated torque based on the intake air amount Qa detected 180 degrees before the generated torque determination timing. This is because the air flow meter 10 is interposed upstream of the intake passage 3 so that the engine 1 rotates about 180 degrees before the intake air amount detected by the air flow meter 10 is actually sucked into each cylinder 6. It corresponds to that.
[0042]
As shown in FIG. 5, the generated torque calculation unit 81 calculates the average value of the generated torque for each stroke 90 deg for each cylinder. For example, in the case of the third cylinder, the average value C3i1 of the generated torque in the first half (0 to 90 deg) of the intake stroke, the average value C3i2 of the generated torque in the second half of the intake stroke (0 to 180 deg), and the first half (180 to 270 deg) of the compression stroke ) Generated torque average value C3c1, the second half of the compression stroke (270-360 deg), the generated torque C3c2, the first half of the expansion stroke (360-450 deg), the average generated torque C3b1, the second half of the expansion stroke (450- The average value C3b2 of the generated torque of 540 deg), the average value C3e1 of the generated torque in the first half of the exhaust stroke (540 to 630 deg), and the average value C3e2 of the generated torque in the second half of the exhaust stroke (630 to 720 deg) are calculated.
[0043]
The generated torque calculation unit 81 always sets the average values C3e1 and C3e2 of the generated torque in the first half and second half of the exhaust stroke to constant values regardless of the operating conditions.
[0044]
6 to 9 show characteristics in which the generated torque is set according to the fuel injection amount Tp (= Qa / Ne) or the like for one cylinder. As the fuel injection amount Tp, that is, the intake air amount Qa increases, the positive generation torque increases in the intake stroke, the compression stroke, and the expansion stroke, and the negative generation torque increases in the compression stroke, but occurs in the exhaust stroke. Torque is substantially constant. As the air-fuel ratio changes from lean to rich, the positive generated torque increases in the expansion stroke, but the generated torque is substantially constant in the other strokes. Further, when the ignition timing changes, the generated torque increases or decreases in the expansion stroke, but the generated torque is substantially constant in the other strokes.
[0045]
As shown in FIG. 5, the inertia torque calculator 82 calculates an average value of the inertia torque TNE every 90 degrees.
[0046]
FIG. 10 shows characteristics in which the inertia torque TNE is set according to the engine speed Ne. As the engine speed Ne increases, the inertia torque TNE increases. Inertia torque TNE can be expressed as a function of engine rotation in which positive and negative are reversed each time engine 1 rotates 90 degrees.
[0047]
The pulsation compensation torque calculator 83 calculates and updates the pulsation compensation torque SUM # obtained by multiplying the sum of the calculated generated torque and the inertia torque TNE by −1 every 90 degrees. By multiplying the sum of the generated torque and the inertia torque TNE by −1, a torque whose absolute value is equal to the torque fluctuation of the engine output shaft 51 and whose sign is reversed is generated in the motor generator 70, and the torque of the engine output shaft 51 is Variations can be counteracted.
[0048]
Pulsation compensation torque calculation unit 83 limits pulsation compensation torque SUM # to be generated by motor generator 70 to be equal to or less than the maximum output of motor generator 70. The maximum output of the motor generator 70 is set according to the rotational speed, temperature, and remaining amount of the battery 73.
[0049]
The flowchart of FIG. 4 shows a control program executed in the M / G control unit 71, which is executed at a constant cycle.
[0050]
To explain this, in step S1, the fuel injection amount Tp, the air-fuel ratio LMD (equal ratio correction factor) of the air-fuel mixture, the engine speed Ne, the ignition timing, the cylinder number, the fuel supply stop (F / C) signal, etc. Is read and the combustion cylinder is determined. In step S2, the generated torques C # c1 to C # i2 for each cylinder are calculated and updated according to the operating conditions. In step S3, the inertia torque TNE is calculated and updated according to the engine speed Ne. The pulsation compensation torque SUM # obtained by multiplying the sum of the generated torque and the inertia torque TNE calculated in step S4 by -1 is calculated and updated every 90 degrees. In step S5, the calculated pulsation compensation torque SUM # is limited so as not to exceed the maximum output of the motor generator 70, and this routine is terminated.
[0051]
As another embodiment, the generated torque calculation unit 83 sets a characteristic obtained by normalizing the generated torque of each cylinder every time the output shaft 52 rotates 180 degrees, and estimates the maximum of each cylinder estimated to the normalized characteristic. The generated torque of each cylinder may be continuously calculated by integrating the generated torque. The maximum generated torque of each cylinder is calculated based on the intake amount, air-fuel ratio, ignition timing, etc. of each cylinder.
[0052]
FIG. 11 shows the result of measuring the generated torque while changing the operating conditions of the engine 1. When this characteristic is normalized by the maximum generated torque for every 180 degrees, all the characteristics are substantially the same as shown in FIG. . This normalized characteristic is stored, and continuous data of the generated torque is obtained by multiplying the maximum generated torque estimated from the intake amount, air-fuel ratio, ignition timing, etc. of each cylinder.
[0053]
The inertia torque can be stored as continuous data in the same manner because the gain differs only for each rotation speed of the engine 1.
[0054]
A pulsation compensation torque is calculated by multiplying the sum of the data of the generated torque and the inertia torque normalized in this way by -1. Thereby, since the pulsation compensation torque is continuously calculated, the torque fluctuation of the engine output shaft 51 can be continuously suppressed as in the case where the strain gauge is used.
[Brief description of the drawings]
FIG. 1 is a system diagram of an engine showing an embodiment of the present invention.
FIG. 2 is a system diagram of a motor generator and the like.
FIG. 3 is a block diagram of the same M / G control unit.
FIG. 4 is a flowchart showing the same control content.
FIG. 5 is an explanatory view showing a calculation example of pulsation compensation torque.
FIG. 6 is a characteristic diagram showing the relationship between the fuel injection amount and the generated torque in the intake stroke.
FIG. 7 is a characteristic diagram showing the relationship between the fuel injection amount and the generated torque in the compression stroke.
FIG. 8 is a characteristic diagram showing the relationship between the fuel injection amount and the generated torque in the expansion stroke.
FIG. 9 is a characteristic diagram showing the relationship between the fuel injection amount and the generated torque in the exhaust stroke.
FIG. 10 is a characteristic diagram showing the relationship between engine speed and generated torque.
FIG. 11 is a characteristic of measuring generated torque by changing engine operating conditions in another embodiment.
FIG. 12 is a characteristic diagram of the generated torque similarly normalized by the maximum generated torque.
[Explanation of symbols]
1 Engine 13 Engine control unit 51 Continuous transmission input shaft 52 Engine output shaft 57 Continuous transmission 70 Motor generator 71 M / G control unit 81 Generated torque calculation unit 82 Inertia torque calculation unit 83 Pulsation compensation torque calculation unit

Claims (11)

An engine for applying torque to the output shaft via a movable member driven by gas burned in the combustion chamber;
An electric motor for applying torque to the output shaft;
In the hybrid prime mover with
Generated torque calculation means for calculating an average generated torque according to the operating state of the engine;
An inertia torque calculating means for calculating an average inertia torque according to the rotational speed of the engine;
Pulsation compensation torque calculating means for calculating a pulsation compensation torque generated by the output shaft according to an average generated torque and an average inertia torque of the engine,
A torque fluctuation control device for a hybrid prime mover, wherein driving or power generation of the electric motor is controlled so that the pulsation compensation torque is obtained. The engine is a four-cycle engine that sequentially reaches an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke every time the output shaft rotates 720 degrees,
2. The torque fluctuation control device for a hybrid prime mover according to claim 1, wherein the generated torque calculating means calculates an average value of the generated torque every time the output shaft rotates 90 degrees. The engine is a four-cycle engine that sequentially reaches an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke every time the output shaft rotates 720 degrees,
The generated torque calculation means reaches a generated torque determination time every time the output shaft rotates 720 degrees, and updates operating conditions as data for calculating the generated torque at the generated torque determination time. 3. A torque fluctuation control device for a hybrid prime mover according to 1 or 2.   The said generated torque calculating means calculates the said generated torque based on the driving | running state detected before the said output shaft rotated 180 degrees from the said generated torque determination time, The hybrid prime mover of Claim 3 characterized by the above-mentioned. Torque fluctuation control device.   5. The torque fluctuation control of a hybrid prime mover according to claim 2, wherein the generated torque calculation means sets the average value of the generated torque in the exhaust stroke to a constant value regardless of operating conditions. 6. apparatus.   2. The hybrid prime mover according to claim 1, wherein the generated torque calculation means sets the characteristic obtained by normalizing the generated torque every time the output shaft rotates 180 degrees and continuously calculates the generated torque. Torque fluctuation control device.   The torque fluctuation control device for a hybrid prime mover according to claim 6, wherein the generated torque calculation means normalizes the generated torque based on a maximum generated torque.   8. The pulsation compensation torque calculating means sets the pulsation compensation torque to a value obtained by multiplying the sum of the output torque and inertia torque of the engine by −1. Torque fluctuation control device for hybrid motor.   The torque fluctuation control device for a hybrid prime mover according to any one of claims 1 to 8, wherein the pulsation compensation torque calculation means limits the pulsation compensation torque to be equal to or less than a maximum output of the electric motor.   10. The torque fluctuation control device for a hybrid prime mover according to claim 9, wherein the pulsation compensation torque calculation means sets a maximum output of the electric motor in accordance with a rotation speed and a temperature of the electric motor. 11. The torque fluctuation control device for a hybrid prime mover according to claim 1, wherein the average inertia torque is calculated in accordance with an engine rotation speed and a rotation phase.

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