JP2000186591A - Ion current detecting device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wrong determination of a misfire or the like according to the ion current detection result by limiting the combustion state determination of an internal combustion engine based on an ion current according to the current flowing through a motor and a motor control device of a hybrid vehicle. SOLUTION: An electric control unit(ECU) 40 reads a voltage value of an ignition plug 16 part generated by an ion current, and compares the read value with a designated value to conduct the required control operation when a misfire is determined. In the ion current detecting device of a hybrid vehicle, when a large current flows through a motor, noise is generated to have a bad influence to the ion current to cause wrong determination of a misfire. When a misfire determination limiting routine is executed, the noise present is determined when the detection values Im of currents of motors MG1, MG2 are larger than a designated amount, when the change rate (dIm/dt) of the detected current value is larger than a designated value, or when a regenerative control current Irm flows. Thus, it is possibe to prevent wrong determination of the engine combustion state according to the detection of an ion current influenced by noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion current detecting device for an internal combustion engine, and more particularly to an ion current detecting device for an internal combustion engine applied to a hybrid vehicle using both the power of an engine and a motor.

[0002]

2. Description of the Related Art A four-cycle internal combustion engine has two pistons.
Intake, compression, expansion (combustion), and exhaust of a mixture of air and fuel in a cylinder (cylinder) by two reciprocating motions 4
One combustion cycle consisting of a stroke is performed. In a four-cycle internal combustion engine, this one combustion cycle is performed during two rotations of the crankshaft, and the expansion work of the combustion gas in the expansion stroke is transmitted to the crankshaft as a rotational force to obtain an output.

[0003] In an internal combustion engine having a plurality of cylinders, if the air-fuel mixture is not optimally and reliably burned during the expansion stroke of each cylinder, an abnormal load is applied to the other cylinders to damage the internal combustion engine or to cause unburned gas outflow. The catalyst that purifies the exhaust gas may be damaged. Therefore, in order to ensure stable operation of the internal combustion engine, in the related art, it is always detected whether or not combustion is reliably performed in each cylinder. For example, the ion current generated between the spark plug gaps during the expansion stroke is determined. And determines whether or not misfire, knock or pre-ignition has occurred, and performs various controls for ensuring stable operation of the internal combustion engine according to the result of the determination. Specifically, as a result of detecting the ion current, when it is determined that a misfire has occurred, the amount of fuel supply to the cylinder next time is increased or stopped, and when it is determined that knock has occurred, the ignition timing of the cylinder is retarded. Side, and when it is determined that pre-ignition has occurred, control such as increasing the amount of fuel supply to the cylinder is performed. For example, Japanese Patent Laid-Open No. 5-2
See No. 6091.

[0004]

However, when the internal combustion engine misfire detection device disclosed in Japanese Patent Application Laid-Open No. 5-26091 is applied to a hybrid vehicle in which a vehicle is driven by using the power of an engine and a motor together, When a large current flows in a motor drive control device including a motor, a generator that supplies electricity for driving the motor, an inverter, and a battery during operation, noise occurs, which affects the ion current. There is a problem that misfire is erroneously determined in spite of normality.

FIGS. 14A and 14B are diagrams showing current waveforms of the ion current. FIG. 14A shows the current waveform of the ion current at the time of normal operation, and FIG. In FIG. 14, the horizontal axis represents time, and the vertical axis represents current value. In hybrid vehicles,
When the current shown in FIG. 14A is normal, that is, when the current flowing through the motor is small, there is no noise in the ion current, so that the detection of the ion current is good, but the noise generation shown in FIG. At the time, that is, when the current flowing through the motor is large, or when the current suddenly changes, noise is added to the ion current.

Therefore, the present invention solves the above-mentioned problem, and does not erroneously determine that a misfire, knock, or pre-ignition has occurred from the detection result of the ion current affected by noise even when applied to a hybrid vehicle. An object of the present invention is to provide an ion current detection device for an internal combustion engine.

[0007]

An ion current detecting device for an internal combustion engine according to a first embodiment of the present invention which solves the above-mentioned problem is such that power output from at least one of the internal combustion engine and the electric motor is transmitted to driving wheels. An ion current detecting device for detecting an ion current generated between electrodes of a spark plug provided in a cylinder of the internal combustion engine; Current detection means for detecting a current flowing to a motor control means for driving a motor; combustion state determination means for determining a combustion state of the internal combustion engine based on an ion current detected by the ion current detection means; Limiting the determination by the combustion state determination means in accordance with the electric current flowing through the electric motor and the electric motor control means detected by the current detection means A baked state determination limiting means, characterized by comprising a.

According to the above configuration, the judgment by the combustion state judging means is limited in accordance with the electric current flowing through the electric motor and the electric motor control means detected by the electric current detecting means. An erroneous determination of the combustion state of the engine can be avoided. In the ion current detection device for an internal combustion engine according to the present invention, the electric motor control means includes a battery and an inverter.

In the ion current detecting device for an internal combustion engine according to the present invention, the motor control means includes a generator for generating electric power based on an output of the internal combustion engine. An ion current detection device for an internal combustion engine according to a second embodiment of the present invention that solves the above-described problem includes control means for controlling transmission of power output from at least one of the internal combustion engine and the electric motor to driving wheels, and the internal combustion engine. Ion current detection means for detecting an ion current generated between the electrodes of the ignition plug provided in the cylinder of, the ion current detection device of the internal combustion engine,
Torque command value calculation means for calculating a torque command value required for the electric motor; combustion state determination means for determining a combustion state of the internal combustion engine based on an ion current detected by the ion current detection means; A combustion state determination restricting unit that restricts the determination by the combustion state determination unit in accordance with the torque command value of the electric motor calculated by the command value calculation unit.

According to the above configuration, the determination by the combustion state determining means is limited in accordance with the torque required for the electric motor detected by the torque command value calculating means. An erroneous determination of the combustion state of the engine can be avoided. In the ion current detection device for an internal combustion engine according to the present invention, the combustion state determination restricting unit restricts the determination by the combustion state determination unit when the operating state of the internal combustion engine is during start-up or acceleration / deceleration.

According to the above limitation, the determination of the combustion state of the engine is not performed at a time when the ion current detection means is easily affected by noise from the electric current flowing through the motor and the motor control means. it can. In the ion current detection device for an internal combustion engine according to the present invention, the combustion state determination restricting means restricts the determination by the combustion state determination means during a period in which the electric motor performs regenerative braking.

According to the above limitation, the combustion state of the engine is not determined at the time of regenerative braking of the electric motor, which is easily affected by the noise from the electric motor and the electric motor control means, so that erroneous judgment of the combustion state of the engine is avoided. it can. The ion current detection device for an internal combustion engine according to the present invention further includes engine stabilization means for stabilizing the internal combustion engine in accordance with the ion current detected by the ion current detection means.

[0013]

FIG. 1 is a block diagram of an embodiment of an ion current detecting device for an internal combustion engine according to the present invention. In the figure,
Reference numeral 1 denotes a cylinder block of an engine generally designated by 100, 2 denotes a piston, 3 denotes a cylinder head, 4 denotes a combustion chamber,
5 indicates an intake manifold, and 6 indicates an exhaust manifold. The intake manifold 5 is connected to an air cleaner 10 through a surge tank 7, an intake duct 8, and an air flow meter 9.
It is connected to the. Throttle valve 1 in intake duct 8
The fuel injection valve 12 is disposed in the intake manifold 5 so as to inject fuel toward the intake port 13. An exhaust pipe 14 is connected to the exhaust manifold 6,
A three-way catalytic converter 15 for purifying three components of HC, CO and NOx at the same time is provided in the exhaust pipe 14. The ignition plug 16 is provided for igniting the air-fuel mixture introduced into the combustion chamber 4.

The electronic control unit 40 is composed of a digital computer and is connected to a ROM 42, a RAM 43, a B.B. RAM 43a, C
A PU 44, an input port 45 and an output port 46 are provided. B. The RAM 43a is a backup RAM provided to keep stored data even when the supply voltage from the battery is lost.

Next, a plurality of detectors for detecting the state of the engine 100 and an input section of the electronic control unit 40 will be described. A water temperature sensor 30 for detecting a cooling water temperature THW is provided in the water jacket of the cylinder block 1. The output signal of the water temperature sensor 30 is input to the input port 45 via the A / D converter 47. The air flow meter 9 generates an output voltage proportional to the intake air amount GA, and this output voltage is also input to the input port 45 via the A / D converter 47. An upstream air-fuel ratio sensor 31 disposed in the exhaust manifold 6 and a downstream air-fuel ratio sensor 32 disposed in the exhaust pipe 14 respectively detect the oxygen concentration in the exhaust, and their output signals are also A / A. The data is input to the input port 45 via the D converter 47.

A crank angle sensor 33 built in the distributor 25 detects the crank angle of the engine 100 and outputs one pulse signal every time the engine 100 rotates at a crank angle of 30 degrees (hereinafter referred to as 30 ° CA). The crank angle reference sensor 34 detects the top dead center T of the compression stroke of the first cylinder every two rotations (720 ° CA) of the crankshaft of the engine 100.
In the vicinity of DC and near the top dead center TDC of the compression stroke of the fourth cylinder having a phase difference of 360 ° CA from this top dead center,
Two pulse signals serving as references are output to determine the injection timing and ignition timing of each cylinder. The cylinder discrimination is performed during two revolutions of the crankshaft after the start of the engine 100 using the two pulse signals. The engine speed NE is calculated from the crank angle reference sensor 34.
The pulse signals from these crank angle sensors are directly input to the input port 45.

On the other hand, the output of the electronic control unit 40
It comprises an output port 46 and drive circuits 48 and 49. The fuel injection valve 12 is connected to a drive circuit 48, is opened according to a conventional fuel injection control, and injects fuel toward the intake port 13. The ignition plug 16 is connected to a drive circuit 49 via an ignition circuit 35 including an ionic current detection circuit for detecting whether or not combustion has been reliably performed in the combustion chamber 4, and according to conventional ignition timing control. At the ignition timing, the combustion of the air-fuel mixture in the combustion chamber 4 is started.
The ion current detection circuit in the ignition circuit 35 includes the ignition plug 1
A voltage signal corresponding to the amount of cations generated in 6 is output to A / D converter 47.

The engine 100 includes a throttle valve 11 from the intake system.
A mixture of the air sucked in through the air and the fuel injected from the fuel injection valve 12 is sucked into the combustion chamber 4, and the linear motion of the piston 2 depressed by the explosion of the mixture is converted into the rotational motion of the crankshaft 51. Convert. The crankshaft 51 is mechanically coupled to a power transmission gear 53 via a planetary gear 52, a starter motor MG1, and a drive motor MG2. The power transmission gear 53 is gear-coupled to a differential gear 54. Therefore, the institution 100,
The power output from any one of the motor MG1 and the motor MG2 is finally transmitted to the left and right drive wheels 55 and 56 of the vehicle.

Next, an ion current detecting device for an internal combustion engine according to the present invention will be described. FIG. 2 is a diagram showing an electric circuit system for detecting an ionic current and preventing ignition at the time of ignition. The electric circuit system shown in FIG. 2 includes an igniter 201, a battery 202, an ignition coil 203, a spark plug 16, an ion current detection circuit 210, and an ECU 40. The igniter 201 includes a primary winding 203a to which a voltage is applied from a battery 202 and a primary winding 203a.
Power transistor 2 connected between power supply 03a and ground
04 and a resistor 204a. One end of a secondary winding 203b of the ignition coil 203 is connected to the ignition plug 16, and the other end is grounded via a capacitor 205 and a diode 206 for preventing a backflow of the ignition current. A zener diode 207 is connected in parallel to the capacitor 205,
A circuit in which a switching element 208 composed of, for example, an SCR and an ion current detection resistor 209 are connected in series is connected in parallel to the diode 206. The ignition plug 16 has a discharge electrode 16a connected to the secondary winding 203b of the ignition coil 203, and a ground electrode 16b opposed to and grounded. Ion current detection circuit 210
Is composed of a capacitor 205, a Zener diode 207, a switching element 208, and a resistor 209.

The ECU 40 outputs a control signal C to the power transistor 204 constituting the igniter 201 and detects, from the terminal 211, an ionic current I generated in the spark plug 16 after the spark plug 16 is discharged based on the control signal C. Further, the ECU 40 includes the switching element 20.
The switching signal S for conducting or blocking the switching element 208 is output to the gate terminal 212 of the switching element 208.

Next, an electric circuit for detecting an ion current will be described below. FIG. 2 is a diagram showing an electric circuit system for detecting an ion current and preventing ignition at the time of misfire and ON ignition. First, the detection of the ion current will be described. Institution 1
00, the control signal C from the ECU 40
The power transistor 204 is turned on / off by the power supply and the current is supplied to and cut off from the primary winding 203 a of the ignition coil 203.
A high voltage is induced at 03b. As a result, a spark discharge is generated from the ground electrode 16b of the ignition plug 16 toward the discharge electrode 16a, and the air-fuel mixture in the combustion chamber 4 is burned. The capacitor 205 is charged by the discharge current at this time. Note that this charging voltage is the Zener diode 207
Is clamped and held at a constant voltage.

When normal combustion is performed in the combustion chamber 4, the electric charge charged in the capacitor 205 is transferred to the resistor 209 and the switching element 20 in the direction shown in FIG.
8. Discharge flows through the secondary winding 203b and the spark plug 16. The voltage generated at both ends of the resistor 209 when the ion current I flows through the resistor 209 is output from the terminal 211 as a voltage value corresponding to the amount of cations generated at the spark plug 16. D converter 4
After being input to A / D conversion 7 and read by the CPU 44.

The ECU 40 compares the voltage value read when the combustion cycle of the engine 100 is in the expansion stroke with a predetermined value to determine misfire, and determines that a misfire has occurred since the read voltage value is smaller than the predetermined value. Increases the fuel injection amount for the cylinder, for example, a plurality of times, and if it is still determined that the misfire is still occurring, turns on the indicator light and stops the fuel supply to the cylinder.

The ECU 40 also determines whether or not knock has occurred based on the voltage signal output from the terminal 211. If it is determined that knock has occurred, control is performed to correct the ignition timing of the cylinder to the retard side. I do. The ECU 40 also determines whether or not pre-ignition has occurred based on the voltage signal output from the terminal 211, and when it is determined that pre-ignition has occurred, controls to increase the amount of fuel supply to the cylinder.

Next, the ON ignition when the control signal C is ON will be described below. The ion current detection circuit 21 shown in FIG.
In order to prevent a current from flowing between the electrodes of the ignition plug 16 when the control signal C is ON, so-called ON ignition is set to 0.
A switching element 208 is provided. FIG. 3 is a time chart illustrating a control example of the switching element 208.
In FIG. 3, the horizontal axis indicates time. The upper part shows the on / off state of the control signal C of the power transistor 204, and the lower part shows the on / off state of the switching signal S of the switching element 208. From FIG. 3, it can be seen that the on / off timings of the control signal C and the switching signal S are inverted.
By sending the switching signal S from the ECU 40 in this way, the electromotive force induced in the secondary winding 203b when the control signal C is turned on causes grounding → the resistor 209 → the switching element 208 → the Zener diode 207 → the secondary winding 2
Even if a current flows through the path from 03b to the spark plug 16 to the ground, the switching element 208 can cut off the current because the switching signal S to the gate of the switching element 208 is off. In this way, the occurrence of on-ignition due to the application of the primary current is accurately prevented.

Next, in the ion current detection device for an internal combustion engine applied to the hybrid vehicle shown in FIG. 1, when a large current flows through the motor during operation of the engine, noise occurs and adversely affects the ion current. The control for avoiding erroneous determination that a misfire has occurred in spite of the normal operating state of the engine will be described below. FIG. 4 is a flowchart of a misfire determination restriction routine. This routine is executed every 720 ° CA at a predetermined cycle. First, step 40
In step 1, the presence / absence of noise is determined based on the detected values of the currents of the motors MG1 and MG2. If it is determined that there is noise, this routine is terminated.
Go to 02. The detection of the currents of the motors MG1 and MG2 is shown in FIG.
Are performed by the current detectors 195 to 198 shown in FIG. In the determination of the presence / absence of the noise, it is determined from the experimental results that noise occurs in the following cases. That is, the current detector 195 to
When the current value Im detected by 198 is larger than a predetermined value, when the rate of change of the detected current value (dIm / dt) is larger than a predetermined value, or when the regenerative braking current Irm flows,
It is determined that noise has occurred (noise is present). Further, the determination of the presence or absence of the noise may be determined from a torque command value required for motors MG1 and MG2 described later.

In step 402, it is determined whether or not the engine 100 has started, based on whether or not the engine speed NE of the engine 100 has exceeded 400 RPM. If NE <400 RPM, it is determined that the engine 100 has started, and this routine is executed. End, NE ≧
At 400 RPM, it is determined that the engine 100 has been started, and the routine proceeds to step 403. In step 403, the engine 100
Is determined to be during acceleration or deceleration. If the determination is YES, this routine ends. If the determination is NO, the routine proceeds to step 404. It is determined whether the engine 100 is accelerating or decelerating based on the intake air amount G detected by the air flow meter.
Load GN = GA / N from A and the engine speed NE of the engine 100
E (g / rev) is calculated, and it is determined from the change rate of the load. In addition, even if the load of the engine 100 is detected from a change in the opening of the throttle valve from an intake pressure sensor (not shown) that detects the air pressure in the intake pipe or from an opening sensor (not shown) of the throttle valve. Good.

In step 404, it is determined whether or not the misfire rate MFR is equal to or greater than a predetermined value K. If MFR ≧ K, it is determined that a misfire has occurred, and the process proceeds to step 405. It is determined that the combustion state of 100 is stable, and this routine ends. The misfire rate MFR is a value obtained by counting the number (x) of misfires detected by the counter during a plurality (n) of combustion cycles of the engine 100 and calculating x / n.

In step 405, the misfire flag MFFLG of the corresponding cylinder is set to 1, and an indicator light (not shown) is turned on to notify the driver of the vehicle. The misfire flag MF
When the FLG is set, the fuel injection amount of the corresponding cylinder is increased to stabilize the combustion state of the engine 100, or the fuel injection of the corresponding cylinder is stopped to discharge unburned HC toward the catalyst. Control so as not to damage the catalyst.

Next, a process of calculating a torque command value required for the motors MG1 and MG2 will be described. Before that, a power output device for the engine and the motor will be described. FIG. 5 is a schematic configuration diagram of the power output device of the engine and the motor shown in FIG. The power output device 200 includes the engine 100, the engine 100
The planetary carrier 52 is mechanically coupled to the crankshaft 51 of the planetary gear 52, the motor MG1 coupled to the sun gear 61 of the planetary gear 52, the motor MG2 coupled to the ring gear 62 of the planetary gear 52, and the motors MG1, MG2. It comprises a motor control device 180. As shown in FIG.
One axis is provided with a resolver 71 for detecting the rotation angle θs, and the axis of the ring gear 62 is provided with a resolver 72 for detecting the rotation angle θr. Here, the planetary gear 52 will be described.

FIG. 6 is a sectional view of the planetary gear. The planetary gear 52 is provided inside the planetary gear 52, and is connected to a hollow sun gear shaft penetrating through the center of the crankshaft 51, and a planetary gear 5.
2 and a plurality of (four in the figure) planetary pinion gears provided between the sun gear 61 and the ring gear 62 and revolving around the sun gear 61 while rotating. 63, a planetary carrier 64 coupled to the end of the crankshaft 51 and supporting the rotating shaft of each planetary pinion gear 63;
It is provided with.

In the planetary gear 52, the sun gear 6
1 is connected to a shaft of MG1 via a sun gear shaft, a ring gear 62 is connected to a shaft of MG2 and connected to a differential gear 54 via a ring gear shaft and a power transmission gear 53, and a planetary pinion gear 63 is connected to a crankshaft 51. Be linked. Sun gear 61, ring gear 62
When the power to be input / output to any two of the three shafts of the sun gear shaft, the ring gear shaft and the crankshaft 51 respectively coupled to the planetary carrier 64 is determined, the power to be input / output to the remaining one shaft is It is determined based on the power that is input to and output from the determined two axes.

Next, the motor control device 180 for controlling the driving of the motors MG1 and MG2 will be described. The motor control device 180 includes a first drive circuit 191 for driving the motor MG1 and a second drive circuit 19 for driving the motor MG2.
2, a motor control unit 190 for controlling the first and second drive circuits, a battery 194 as a secondary battery, and the like. The motor control unit 190 includes a CPU (not shown), a RAM, a ROM, an input port, an output port,
The ECU 40 includes a / D converter, a drive circuit, and the like.
It has an interface to communicate with. The motor control unit 190 includes a rotation angle θs of the sun gear shaft from the resolver 71, a rotation angle θr of the ring gear shaft from the resolver 72, and an accelerator pedal position sensor 164a.
Pedal position AP (depression amount of accelerator pedal 164), brake pedal position sensor 1
Brake pedal position BP (depression amount of brake pedal 165) from 65a, shift position sensor 18
4, the shift position SP (switching position of the shift lever 182), the current values Iu1 and Iv1 from the two current detectors 195 and 196 provided in the first drive circuit 191, and the shift position SP provided in the second drive circuit 192. Two current detectors 19
7, 198, and the remaining capacity BR from the remaining capacity detector 199 for detecting the remaining capacity of the battery 194.
M or the like is input to the input port directly or via an A / D converter.

A description will now be given of a process of calculating a torque command value required for the motors MG1 and MG2 for determining the presence or absence of noise when detecting an ion current. FIG.
6 is a flowchart of a torque control routine of the power output device shown in FIG. This routine is performed by the motor control unit (M) of the motor control device 180 in the power output device 200.
CU) 190 at predetermined intervals, for example, every 1 ms. First, at step 701, the rotational speed Nr of the ring gear shaft is read. The rotation speed Nr of the ring gear shaft is obtained from the rotation angle θr of the ring gear shaft detected by the resolver 72. In step 702, the accelerator pedal position AP detected from the accelerator pedal position sensor 164a is read. In step 703, a torque Tr to be output to the ring gear shaft is calculated. Here, a map for calculating the torque Tr will be described.

FIG. 8 is a diagram showing a map for calculating a torque command value Tr from the rotational speed Nr and the accelerator pedal position AP. The rotational speed Nr of the ring gear shaft is
The accelerator pedal position AP is obtained by reading the output of the accelerator pedal position sensor 164a.
The torque command value Tr is calculated from the rotational speed Nr of the ring gear shaft and the accelerator pedal position AP according to a map shown in FIG.

Returning to FIG. In step 704,
The output energy Pr (= Tr × Nr) to be output to the ring gear shaft is calculated from the output command value Tr and the rotation speed Nr.
In step 705, a target torque Tet and a target rotation speed Net of the engine 100 are set based on the output energy Pr calculated in step 704. The energy Pr output to the engine 100 is equal to the product of the torque and the number of revolutions of the engine 100, and there are countless combinations. The number Net is set as shown below.

Pr = Tet × Net Next, at step 706, the target rotational speed N of the sun gear shaft
The target rotational speed Net, which is set in place of the rotational speed Ne of the engine 100 in place of st, is substituted into the following equation to obtain the target rotational speed Net. Ns = Nr- (Nr-Net) .times. [(1 + .rho.) /. Rho.] Where .rho. = The number of teeth of the sun gear / the number of teeth of the ring gear In steps 707 to 709, the set target torque Tet and target rotation speed Net of the engine 100 are set. Motor MG1 (FIG. 9) and the motor MG using the target rotation speed Nst of the sun gear shaft.
2 (FIG. 13) and the control of the engine 100 are executed.

As for the control of the engine 100, Step 7
Target torque Tet and target rotation speed Net set in 05
It is controlled to be driven by. Specifically, from the motor control unit (MCU) 190 to the electronic control unit (E
The target torque Tet and the target rotation speed Net are transmitted to the CU) 40 by communication, and the ECU 40 receives them and
The opening degree control of the throttle valve 11, the control of the fuel injection amount from the fuel injection valve 12, and the ignition plug 1 are performed so that the torque and the rotation speed of 00 become the target torque Tet and the target rotation speed Net.
The ignition timing of No. 6 is controlled.

Next, a process of calculating a torque command value required for the motor MG1 will be described. FIG. 9 is a flowchart of a control routine for the motor MG1. This routine is executed by the motor control unit (MCU) 190 of the motor control device 180 in the power output device 200 at a predetermined cycle, for example, every 1 ms. First, in step 901, the number of rotations Ns of the sun gear shaft is read. The rotation speed Ns of the sun gear shaft is obtained from the rotation angle θs of the sun gear shaft detected by the resolver 71. Next, at step 902, the read rotation speed Ns of the sun gear shaft and the target torque T of the engine 100 set by the torque control routine of FIG.
The torque command value Tct (= Tm1t) of the motor MG1 is calculated from the following equation using et and the target rotation speed Nst of the sun gear shaft.

Tm1t = Tet [ρ / (1 + ρ)] + k3
(Nst−Ns) + k4∫ (Nst−Ns) dt Here, k3 and k4 are proportional constants. The first on the right side of the above equation
The term is obtained from the balance of the operating collinear in the alignment chart described below with reference to FIGS. 10 to 12, and the second term on the right side is a proportional term that cancels the deviation of the rotation speed Ns from the target rotation speed Nst, The third term on the right side is an integral term for eliminating the steady-state error.
Therefore, in a steady state (when the deviation of the rotation speed Ns from the target rotation speed Nst is 0), the torque command value Tm1 of the motor MG1 is determined by the first right-hand side obtained from the balance of the operating collinear line.
Will be set equal to the term.

Before explaining the alignment chart, the operation of the power output apparatus will be briefly described. FIG. 10 is a diagram showing the relationship between the rotation speed and torque of the engine and the ring gear shaft in the power output device shown in FIG. FIG. 10 shows that the engine 100 is operated at a rotation speed Ne, a torque Te, and an output P (= P1),
When the ring gear shaft is operated at the same output P but different rotation speed Nr, torque Tr, and output P2, that is, when the power output from the engine 100 is converted into torque and applied to the ring gear shaft. 4 shows the relationship between the rotation speed and torque of the engine 100 and the ring gear shaft.

FIG. 11 is a first alignment chart showing the relationship between the rotational speed and torque of the three shafts connected to the planetary gears in the power output device shown in FIG. FIG. 12 is a second alignment chart. The three axes of the planetary gear 52 (the sun gear axis, the ring gear axis, and the planetary carrier 64 (the crankshaft 5
According to the teaching of the mechanics, the relationship between the rotation speed and the torque in 1) can be expressed as a diagram called a collinear diagram illustrated in FIGS. 11 and 12 and can be solved geometrically. The relationship between the rotation speed and the torque of the three axes in the planetary gear 52 can be mathematically analyzed by calculating the energy of each axis without using the above-mentioned alignment chart. In the present embodiment, a description will be given using a collinear chart for ease of description.

In FIG. 12, the vertical axis is the three rotation speed axes, and the horizontal axis is the ratio of the three polar positions. That is,
When the coordinate axes S and R of the sun gear axis and the ring gear axis are set at both ends, the coordinate axis C of the planetary carrier 64 is determined as an axis that internally divides the axis S and the axis R into 1: ρ. here,
ρ = number of teeth of sun gear / number of teeth of ring gear. Now, it is assumed that the engine 100 is operating at the rotation speed Ne and the ring gear shaft is operating at the rotation speed Nr. Therefore, the coordinate axis C of the planetary carrier 64 to which the crankshaft 51 of the engine 100 is coupled is assumed. The rotation speed N of the engine 100
can be plotted on the coordinate axis R of the ring gear shaft. By drawing a straight line passing through these two points, the rotation speed Ns of the sun gear shaft can be obtained as the rotation speed represented by the intersection of the straight line and the coordinate axis S. This straight line is called an operating collinear line. The rotation speed Ns can be obtained by the following equation using the rotation speed Ne and the rotation speed Nr.

Ns = Nr− (Nr−Ne) × [(1 + ρ) / ρ] Thus, in the planetary gear 52, the sun gear 61,
When any two rotations of the ring gear 62 and the planetary carrier 64 are determined, the remaining one rotation is determined based on the determined two rotations. Next, the torque Te of the engine 100 is applied to the drawn operation collinear line from the bottom to the top as an action line of the coordinate axis C of the planetary carrier 64. Since this motion collinear can be treated as a rigid body when a force as a vector is applied to the torque, the torque Te applied on the coordinate axis C is equal to the force applied to two different parallel lines of action. Can be separated into a torque Tes on the coordinate axis S and a torque Ter on the coordinate axis R. At this time, the magnitudes of the torques Tes and Ter are expressed by the following two equations.

Tes = Te × [ρ / (1 + ρ)] Ter = Te × [1 / (1 + ρ)] In order for the operating collinear to be stable in this state, the forces of the operating collinear may be balanced. . That is, on the coordinate axis S, the torque T of the same magnitude as the torque
m1 is applied, and on the coordinate axis R, a torque Tm2 having the same magnitude and the opposite direction is applied to the resultant force of the torque Tor and the torque Ter having the same magnitude as the torque Tr output to the ring gear shaft and having the opposite direction. It is. The torque Tm1 can be applied by the motor MG1, and the torque Tm2 can be applied by the motor MG2. At this time, the motor MG1 applies a torque in a direction opposite to the direction of rotation.
Functions as a generator, and regenerates electric energy Pm1 represented by the product of the torque Tm1 and the rotation speed Ns from the sun gear shaft. In the motor MG2, since the direction of rotation and the direction of torque are the same, the motor MG2 operates as an electric motor and outputs electric energy Pm2 represented by the product of the torque Tm2 and the number of revolutions Nr to the ring gear shaft as power.
Here, if the electric energy Pm1 is made equal to the electric energy Pm2, all of the electric power consumed by the motor MG2 can be regenerated and supplied by the motor MG1. For this purpose, all of the input energy may be output, and therefore, the energy Pe output from the engine 100 and the energy Pr output to the ring gear shaft may be made equal. That is, the energy Pe expressed by the product of the torque Te and the rotation speed Ne is made equal to the energy Pr expressed by the product of the torque Tr and the rotation speed Nr.

Referring to FIG. 10, the torque Te output from the engine 100 operating at the output P1 and the rotational speed N
is converted into torque and output to the ring gear shaft as power represented by the torque Tr and the rotational speed Nr with the same energy. As described above, the power output to the ring gear shaft is transmitted to the drive shaft via the power transmission shaft, and transmitted to the drive wheels 55 and 56 via the differential gear 54. Therefore, since a linear relationship is established between the power output to the ring gear shaft and the power transmitted to the drive wheels 55 and 56, the drive wheels 55 and
6, the power transmitted to the ring gear shaft can be controlled.

In the alignment chart shown in FIG. 11, the rotation speed Ns of the sun gear shaft is positive, but depending on the rotation speed Ne of the engine 100 and the rotation speed Nr of the ring gear shaft, as shown in the alignment chart of FIG. May be negative. At this time, in the motor MG1, the direction of rotation and the direction in which the torque acts are the same, so that the motor MG1 operates as an electric motor, and the electric energy P represented by the product of the torque Tm1 and the number of revolutions Ns
Consumes m1. On the other hand, in the motor MG2, since the direction of rotation and the direction in which torque acts are opposite, the motor MG2
Operates as a generator, and regenerates electric energy Pm2 represented by the product of torque Tm2 and rotation speed Nr from the ring gear shaft. In this case, the electric energy Pm1 consumed by the motor MG1 and the electric energy P regenerated by the motor MG2
By making m2 equal, the electric energy Pm1 consumed by the motor MG1 can be exactly covered by the motor MG2.

Although the basic torque conversion in the power output device of the present invention has been described above, the power output device of the present invention converts all the power output from the engine 100 into a torque and outputs the converted power to the ring gear shaft. In addition to institution 1
In addition to the operation of converting all of the power output from the motor 00 to the torque and outputting the torque to the ring gear shaft, the power output from the engine 100 (the product of the torque Te and the rotation speed Ne) and the motor M
Electric energy Pm1 regenerated or consumed by G1;
By adjusting the electric energy Pm2 consumed or regenerated by the motor MG2, an operation of finding surplus electric energy and discharging the battery 194, an operation of supplementing the insufficient electric energy with the electric power stored in the battery 194, and the like. Various operations can be performed.

In the above operating principle, the planetary gear 52, the motor MG1, the motor MG2, the transistor T
The power conversion efficiency by r1 to Tr16 and the like is set to a value 1 (= 1
00%). In practice, since the efficiency is lower than 100%, the energy Pe output from the engine 100 is set to a value slightly larger than the energy Pr output to the ring gear shaft, or conversely, the energy Pr output to the ring gear shaft is output from the engine 100. It is necessary to make the value slightly smaller than the energy Pe. For example, the energy Pe output from the engine 100 may be a value calculated by multiplying the energy Pr output to the ring gear shaft by the reciprocal of the conversion efficiency. Further, the torque Tm2 of the motor MG2 is a value calculated from the power regenerated by the motor MG1 multiplied by the efficiency of both motors in the state of the alignment chart of FIG.
In the state of the collinear chart, the power consumed by the motor MG1 may be calculated by dividing the power consumed by the motor MG1 by the efficiency of both motors. In the planetary gear 52, energy is lost as heat due to mechanical friction or the like. However, the loss is extremely small in view of the total amount, and the efficiency of the synchronous motor used for the motors MG1 and MG2 is extremely close to 100%. It is also known that the transistors Tr1 to Tr16 have extremely low on-resistance. Therefore, the power conversion efficiency is extremely close to 100%.

Returning to the flowchart of FIG. In step 903, the rotation angle θs of the sun gear shaft detected by the resolver 71 is read. In step 904, the current values Iu1 and Iu1 detected by the current detectors 195 and 196,
Read Iv1. In step 905, the following coordinate conversion (three-phase to two-phase conversion) is performed. The coordinate conversion is to convert the current values of the d-axis (linear component) and the q-axis (horizontal component) of the permanent magnet type synchronous motor. And the q-axis current is an essential amount in torque control. It is also possible to control three phases from the beginning.

[0051]

(Equation 1)

Next, at step 906, a voltage command value is calculated. That is, after the current values are converted into two-axis current values in step 905, the current values Id1 and Iq1 flowing through each axis obtained from the torque command value Tct of the motor MG1 and the deviation ΔId1 (=
Id1t-Id1) and ΔIq1 (= Iq1t-Iq1) are obtained, and the voltage command values Vd1 and Vq1 of each axis are proportional to the deviation ΔI and the deviation Δ
It is determined by the following formula from the accumulated value of I times.

Vd1 = kp1 × ΔId1 + Σki1 × ΔId1 Vq1 = kp2 × ΔIq1 + Σki2 × ΔIq1 Here, kp1, kp2, ki1 and ki2 are respective coefficients set so as to conform to the characteristics of the motor. Next, at step 907, inverse coordinate conversion (two-phase to three-phase conversion) of the voltage command value is performed by the following equation, and voltages Vu1, Vv1, and Vw1 to be actually applied to the three-phase coil of the motor MG1 are obtained.

[0054]

(Equation 2)

Next, at step 908, the transistors Tr1 to Tr6 of the first drive circuit 191 are turned on and off to perform PWM.
Execute control. The calculation process of the torque command value required for motor MG2 will be described. FIG. 13 shows the motor MG2.
4 is a flowchart of a control routine of FIG. This routine is executed by the motor control unit (MCU) 190 of the motor control device 180 in the power output device 200 for a predetermined period.
For example, it is executed every 1 ms. First, step 1301
Then, using the torque command value Trt to be output to the ring gear shaft and the torque command value Tm1t of the motor MG1, the motor MG2 which is the torque command value to be output to the sun gear shaft from the following equation.
Of the torque command value Tat (= Tm2t) required for the above.

Tm2t = Trt-Tm1t / ρ In step 1302, the rotation angle θr of the ring gear shaft detected by the resolver 72 is read. Step 130
In step 3, the current values Iu2 and Iv2 detected by the current detectors 197 and 198 are read. In step 1304, the following coordinate conversion (three-phase to two-phase conversion) is performed. The coordinate conversion is to convert the current values of the d-axis (linear component) and the q-axis (horizontal component) of the permanent magnet type synchronous motor. And the q-axis current is an essential amount in torque control. It is also possible to control three phases from the beginning.

[0057]

(Equation 3)

Next, at step 1305, a voltage command value is calculated. That is, the current values Id2 and Iq2 flowing through each axis obtained from the torque command value Tat of the motor MG2 after the conversion into the current values of the two axes in step 1304 and the deviation ΔId2
(= Id2t−Id2) and ΔIq2 (= Iq2t−Iq2), and the voltage command values Vd2 and Vq2 of each axis are obtained from the following equation from the proportional component of the deviation ΔI and the accumulated component of the deviation ΔI for i times.

Vd2 = kp1 × ΔId2 + Σki1 × ΔId2 Vq2 = kp2 × ΔIq2 + Σki2 × ΔIq2 Here, kp1, kp2, ki1 and ki2 are respective coefficients set so as to conform to the characteristics of the motor. Next, at step 1306, the reverse coordinate conversion of the voltage command value (two-phase
The three-phase conversion) is performed by the following equation, and the voltages Vu2, Vv2, and Vw2 actually applied to the three-phase coil of the motor MG1 are obtained.

[0060]

(Equation 4)

Next, at step 1307, the transistors Tr11 to Tr16 of the second drive circuit 192 are turned on and off to execute PWM control. As described above, the motor M
The torque command value Tct required for G1 is calculated by step 902 in the flowchart of FIG. 9, and the torque command value Tat required for motor MG2 is calculated by step 1301 in the flowchart of FIG. Since the calculated required torque command values Tct and Tat correspond to the current values of the motors MG1 and MG2, the determination of the presence / absence of noise with respect to the ion current is based on the required torque command value Tc.
When t and Tat are larger than predetermined values, the required torque command value Tc
When the rate of change of t, Tat (dTct / dt, dTat / dt) is greater than a predetermined value, or when the required torque command values Tct, Tat are suddenly set to 0 so as to perform regenerative braking,
It is determined that noise has occurred (noise is present).

The hybrid vehicle system to which the present invention can be applied is not limited to the above embodiment. The present invention is also applicable to a series type, a parallel type, a coexistence type of both, and the like.

[0063]

As described above, according to the present invention,
Since the determination by the combustion state determining means is limited in accordance with the electric current flowing through the electric motor and the electric motor control means detected by the electric current detection means, the combustion of the engine based on the detection of the ion current affected by the noise by the electric motor and the electric motor control means Misjudgment of the state can be avoided.

As described above, according to the present invention, the determination by the combustion state determining means is limited in accordance with the torque required for the motor detected by the torque command value calculating means. An erroneous determination of the combustion state of the engine based on the detection of the ion current affected by the noise can be avoided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of an ion current detection device for an internal combustion engine according to the present invention.

FIG. 2 is a diagram showing an electric circuit system that detects an ion current and prevents ignition at the time of misfire and ON ignition.

FIG. 3 is a time chart illustrating a control example of a switching element.

FIG. 4 is a flowchart of a misfire determination restriction routine.

FIG. 5 is a schematic configuration diagram of a power output device of the engine and the motor shown in FIG. 1;

FIG. 6 is a sectional view of a planetary gear.

7 is a flowchart of a torque control routine of the power output device shown in FIG.

FIG. 8 is a diagram showing a map for calculating a torque command value Tr from a rotational speed Nr and an accelerator pedal position AP.

FIG. 9 is a flowchart of a control routine for a motor MG1.

10 is a diagram showing a relationship between the engine and the rotation speed and torque of a ring gear shaft in the power output device shown in FIG. 5;

11 is a first collinear diagram showing a relationship between a rotation speed and a torque of three shafts coupled to a planetary gear in the power output device shown in FIG. 5;

12 is a second alignment chart showing a relationship between the rotation speed and the torque of the three shafts coupled to the planetary gears in the power output device shown in FIG. 5;

FIG. 13 is a flowchart of a control routine for a motor MG2.

FIG. 14 is a diagram showing a current waveform of an ion current;
(A) is a diagram showing a current waveform of an ion current at the time of normality, and (B) is a diagram showing a current waveform of an ion current at the time of noise generation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder block 2 ... Piston 4 ... Combustion chamber 5 ... Intake manifold 6 ... Exhaust manifold 12 ... Fuel injection valve 16 ... Ignition plug 35 ... Ignition circuit 40 ... Electronic control unit (ECU) 51 ... Crank shaft 52 ... Planetary gear 61 ... Sun gear 62 ring gear 63 planetary pinion gear 64 planetary carrier 71, 72 resolver 180 motor controller 190 motor control unit (MCU) 194 battery 195, 196, 197, 198 current detector MG1, MG2 motor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60K 8/00 B60K 9/00 Z (72) Inventor Hiroshi Kanai 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor (72) Inventor Toshifumi Takaoka 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Toshio Inoue 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masaki Kusada 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Takashi Suzuki 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Makoto Yamazaki Toyota Town, Toyota City, Aichi Prefecture No. 1 Toyota Motor Corporation F term (reference) 3G019 AA09 BA01 CD09 DC06 EA01 3G084 AA03 BA13 DA04 DA28 EA02 FA07 FA10 FA19 FA20 FA24 FA30 FA33 FA39 3G093 AA07 BA04 BA14 BA20 CA01 CA05 CB00 DA00 DA01 DA05 DA06 DA07 DA09 DA11 DA12 DB01 DB19 DB20 DB28 EA05 FA10 FB05

Claims (7)

[Claims] A control means for controlling transmission of power output from at least one of an internal combustion engine and an electric motor to driving wheels, and an ionic current generated between electrodes of a spark plug provided in a cylinder of the internal combustion engine Current detection means for detecting an electric current, wherein the current detection means detects current flowing to the electric motor and a motor control means for driving the electric motor, and the ion current detection means Combustion state determining means for determining a combustion state of the internal combustion engine based on the ionic current detected by the motor; and the combustion state determining means in response to a current flowing through the electric motor and the electric motor control means detected by the current detecting means Combustion state determination limiting means for limiting the determination by
An ion current detection device for an internal combustion engine, comprising: 2. The ionic current detection device for an internal combustion engine according to claim 1, wherein said motor control means includes a battery and an inverter. 3. The electric motor control means includes a generator for generating electric power based on an output of the internal combustion engine.
Or the ion current detection device for an internal combustion engine according to 2. 4. A control means for controlling transmission of power output from at least one of an internal combustion engine and an electric motor to driving wheels, and an ionic current generated between electrodes of a spark plug provided in a cylinder of the internal combustion engine. Current detection device for an internal combustion engine, comprising: a torque command value calculation device that calculates a torque command value required for the electric motor; and an ion detected by the ion current detection device. Combustion state determining means for determining a combustion state of the internal combustion engine based on a current; and a combustion state for limiting the determination by the combustion state determining means in accordance with a torque command value of the electric motor calculated by the torque command value calculating means. An ion current detection device for an internal combustion engine, comprising: a determination restriction unit. 5. The internal combustion engine according to claim 3, wherein the combustion state determination restricting unit restricts the determination by the combustion state determination unit when the operating state of the internal combustion engine is during start-up or acceleration / deceleration. Ion current detector. 6. The ionic current detection device for an internal combustion engine according to claim 3, wherein said combustion state determination limiting means limits the determination by said combustion state determination means during a period in which said electric motor performs regenerative braking. 7. The engine according to claim 1, further comprising engine stabilizing means for stabilizing the internal combustion engine in accordance with the ion current detected by the ion current detecting means.
Item 10. The ion current detection device for an internal combustion engine according to item 8.