JP2018199373A - Crank angle estimation method of hybrid vehicle, crank angle control method of hybrid vehicle, and crank angle estimation device of hybrid vehicle - Google Patents

Abstract

To provide a crank angle estimation method of a hybrid vehicle, a crank angle control method of a hybrid vehicle, and a crank angle estimation device of a hybrid vehicle capable of improving crank angle estimation accuracy.SOLUTION: A motor controller 12 connects an engine 1 and a motor 5; drives the motor 5 in a direction that the engine 1 is reversely rotated in a state that fuel injection and ignition for the engine 1 are stopped; detects a motor rotation angle θm when the engine 1 is reversely rotated; calculates a disturbance torque estimation value Trbst that acts on the motor 1; and based on the relationships between θm when the sign of the gradient of the Trbst is reversed and a crank angle θint when an intake valve of a cylinder #1 of the engine 1 is opened, calculates a crank angle estimation value θc from the motor rotation angle θm.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a crank angle estimation method, a crank angle control method, and a crank angle estimation device for a hybrid vehicle.

  Conventionally, in a hybrid vehicle using an engine and a motor as a power source, a crank angle is estimated using a detection value of a motor angle sensor and a detection value of a crank angle sensor (see, for example, Patent Document 1).

Japanese Patent No. 3770235

However, the conventional crank angle estimation method has a problem that the estimation accuracy of the crank angle is low because the estimation accuracy of the crank angle depends on the detection variation of the crank angle sensor.
One of the objects of the present invention is to provide a crank angle estimation method, a crank angle control method, and a crank angle estimation device for a hybrid vehicle that can improve the estimation accuracy of the crank angle.

  In the crank angle estimation method for a hybrid vehicle according to an embodiment of the present invention, the motor rotation angle when the motor is driven and the engine is rotated in the reverse direction is detected or estimated, and disturbance torque acting on the motor is estimated. Then, based on the relationship between the motor rotation speed when the sign of the disturbance torque gradient is reversed and the crank angle when the intake valve of a predetermined cylinder of the engine opens, an estimated crank angle value is calculated from the motor rotation angle.

  Therefore, the crank angle estimation method for a hybrid vehicle according to the present invention can improve the estimation accuracy of the crank angle.

It is a schematic block diagram of the power train in the hybrid vehicle of Embodiment 1. FIG. 3 is a schematic configuration diagram of a powertrain control system according to the first embodiment. 1 is a schematic configuration diagram of a motor controller 12 according to a first embodiment. FIG. 3 is a block diagram illustrating crank angle estimation control according to the first embodiment. FIG. 5 is a relationship diagram between a crank angle of the engine 1 and intake / exhaust valve opening / closing timing. FIG. 3 is a relationship diagram between a combustion stroke of the engine 1 and intake / exhaust valve opening / closing timing. FIG. 3 is a relationship diagram between a crank angle of the engine 1 and an engine compression reaction force. 3 is a characteristic diagram of a compression reaction force generated for each cylinder of the engine 1. FIG. It is a compression reaction force characteristic figure in case an initial position is an arbitrary position which is not a compression top dead center. FIG. 4 is a relationship diagram between an initial crank angle (ATDC conversion) and a maximum compression reaction force ratio. 4 is a flowchart showing a specific processing flow of crank angle estimation control and vibration suppression optimal crank angle control according to the first embodiment. 3 is a time chart illustrating a crank angle estimation operation according to the first embodiment.

Embodiment 1
FIG. 1 is a schematic configuration diagram of a power train in the hybrid vehicle of the first embodiment.
In the hybrid vehicle according to the first embodiment, the automatic transmission 3 is arranged in tandem on the vehicle longitudinal direction rear side of the engine (power source) 1, and the rotation of the engine 1 from the crankshaft 1 a is transmitted to the transmission input shaft of the automatic transmission 3. A motor generator 5 (hereinafter referred to as a motor) is provided in combination with the motor torque shaft 4 for transmission to 3a. The engine 1 is a 6-cylinder, 4-stroke reciprocating gasoline engine in which the opening / closing timing of the intake and exhaust valves is linked to the rotational movement of the crank angle. The motor 5 is located between the engine 1 and the automatic transmission 3 and outputs torque to the motor torque shaft 4. The motor 5 functions as an electric motor or a generator depending on the operating state. A first clutch 6 is interposed between the crankshaft 1a and the motor torque shaft 4, and the engine 1 and the motor 5 are detachably coupled by the first clutch 6. The first clutch 6 is capable of continuously changing the transmission torque (clutch engagement) capacity. For example, the transmission torque (clutch engagement) capacity is controlled by continuously controlling the clutch hydraulic oil flow rate and the clutch hydraulic pressure with a proportional solenoid. The wet multi-plate clutch can be changed.

  The motor 5 and the automatic transmission 3 are directly connected to each other by the connection between the motor torque shaft 4 and the transmission input shaft 3a. The automatic transmission 3 is a stepped type, and the rotation from the transmission input shaft 3a is shifted at a gear ratio corresponding to the selected shift speed and is output to the transmission output shaft 3b. The rotation of the transmission output shaft 3b is distributed and transmitted to the left and right rear wheels (drive wheels) 2 and 2 by the differential gear device 8, and is used for traveling of the vehicle. In the first embodiment, as the second clutch 7 that detachably couples the motor 5 and the rear wheels 2 and 2, a shift friction element for selecting a forward shift stage or a shift for selecting a reverse shift stage existing in the automatic transmission 3 is used. Diverting friction elements. Similar to the first clutch 6, the second clutch 7 can continuously change the transmission torque capacity.

  In the power train shown in FIG. 1, when the electric travel (EV) mode used at low load and low vehicle speed including when starting from a stopped state is required, the first clutch 6 is released and the second clutch 7 To put the automatic transmission 3 into a power transmission state. By driving the motor 5 in this state, the vehicle travels only with the output of the motor 5 (EV traveling). On the other hand, when the hybrid travel (HEV travel) mode used for high speed travel or heavy load travel is required, both the first clutch 6 and the second clutch 7 are engaged, and the automatic transmission 3 is brought into the power transmission state. To do. By driving the engine 1 and the motor 5 in this state, the vehicle travels by the outputs of both the engine 1 and the motor 5 (HEV travel). In the HEV driving mode, when the engine 1 is operated with the optimum fuel efficiency, when the energy becomes surplus, the surplus energy is converted into electric power by operating the motor 5 as a generator by this surplus energy, and this generated power is converted into the electric power of the motor 5. The fuel consumption of the engine 1 can be improved by storing the electric power so as to be used for driving the motor.

FIG. 2 is a schematic configuration diagram of a powertrain control system according to the first embodiment.
The vehicle controller 10 calculates the target drive torque of the vehicle based on the engine speed, motor rotation, and vehicle information (accelerator opening, vehicle speed, gear position, power generation request, first clutch engaged state, etc.), and the target drive torque Is distributed to the target engine torque and the target motor torque and output to the controllers 11 and 12. The engine controller 11 calculates an engine torque command for realizing the target engine torque, and drives the engine 1. The engine controller 11 calculates the engine speed from the crank angle detected by the crank angle sensor 13. The motor controller 12 calculates a motor torque command value that realizes the target motor torque, and drives the motor 5. The motor controller 12 calculates the motor rotation speed from the motor rotation angle detected by the resolver 14.

FIG. 3 is a schematic configuration diagram of the motor controller 12 according to the first embodiment.
The motor controller 12 inputs the target motor torque and the motor rotation speed from the vehicle controller 10 and outputs the motor rotation speed to the vehicle controller 10. The motor controller 12 includes a rotation speed calculation unit 15, a motor torque control unit 16, a motor current control unit 17, and a crank angle estimation unit 18. The rotation speed calculation unit 15 calculates the motor rotation speed from the output of the resolver 14. The motor torque control unit 16 calculates a motor torque command value from the target motor torque, the motor rotation angle, the motor rotation speed, and a crank angle estimated value described later, and outputs the motor torque command value to the motor current control unit 17. The motor current control unit 17 determines the motor drive current according to the motor torque command value and outputs it to the inverter 19. The inverter 19 supplies a three-phase current to the motor 5 according to the motor drive current. The crank angle estimation unit 18 calculates a crank angle estimation value from the motor rotation angle and a disturbance torque estimation value (compression reaction force estimation value) described later, and outputs the crank angle estimation value to the motor torque control unit 16.

  The motor controller 12 controls the first clutch 6 when the engine 1 is stopped in a stopped state in order to suppress floor vibration that occurs when the engine is started from a stopped state, such as when the engine is restarted after an idle stop. The second clutch 7 is engaged, and the motor 5 is angle-controlled (rotational speed control) based on the crank angle estimated value calculated by the crank angle estimator 18 so that the crank angle becomes a predetermined vibration suppression optimum crank angle. ) Perform the optimal crank angle control. The vibration suppression optimum crank angle is an initial crank angle that can suppress the amplitude level of floor vibration generated when the engine speed passes through the resonance band to an allowable level, that is, an initial crank angle effective for vibration suppression. Since there is a correlation between the initial crank angle and the amplitude level of the floor vibration, the optimum vibration suppression crank angle is obtained in advance by experiments, simulations, or the like.

In the above-mentioned optimum crank angle control, it is important to improve the estimation accuracy of the crank angle. However, in the conventional crank angle estimation method, the estimation accuracy deteriorates because the estimation accuracy of the crank angle depends on the detection variation of the crank angle sensor. There is a scene to do. Therefore, in the first embodiment, with the aim of improving the estimation accuracy of the crank angle, the crank angle estimation control unit 18 executes the crank angle estimation control as described below prior to the above-described optimal crank angle control.
FIG. 4 is a block diagram illustrating crank angle estimation control according to the first embodiment.
First, a negative rotation angle command value θm * is set as the rotation angle command value of the motor 5 necessary for crank angle estimation in order to rotate the engine 1 in the reverse rotation direction. The “reverse direction” is a direction opposite to the rotational direction (forward direction) that becomes the combustion stroke of the engine 1. “Turning” is a state in which the crankshaft 1a is rotated by the motor 5 in a state where fuel injection and ignition to the engine 1 are stopped.

The addition point 20 generates a difference between θm * and the motor rotation angle θm.
The gain block 21 multiplies the output of the addition point 20 by a predetermined gain a to generate a motor rotation speed command value ωm *.
The summing point 22 generates the difference between ωm * and the motor rotational speed ωm.
The multiplier 23 multiplies the output of the addition point 22 by a predetermined gain b to generate a motor torque command value Tm *.
The addition point 24 generates a final motor torque command value Tfin * that is a difference between Tm * and a disturbance torque estimated value Trbst described later.
The actual plant block 25 represents an actual plant as a control target (motor 5) instead. The actual plant block 25 multiplies Tfin * by the transfer function Gp ′ (s) to generate ωm. By outputting Tfin * to the actual plant, the angle of the motor 5 can be controlled so as to follow and converge on θm *.

The integration block 26 integrates ωm to generate a motor rotation angle θm.
The filter block 27 has a function as a low-pass filter, and generates the reference motor torque Tref by multiplying Tfin * by the transfer function H (s).
The filter block 28 functions as a filter, and multiplies ωm by a transfer function H (s) / Gp (s) to generate a motor applied torque estimated value Tact. Gp (s) is a model of the transfer function between the torque input to the controlled object and the motor rotation speed. That is, the transfer function H (s) / Gp (s) is the inverse model 1 / Gp (s) of the transfer function H (s) and the transfer function Gp (s) between the torque input to the controlled object and the motor rotation speed. Is the product of H (s) / Gp (s) is a proper transfer function. That is, in the fractional function representing H (s) / Gp (s), the numerator order is lower than the denominator order. The filter blocks 27 and 28 are disturbance torque estimation units.
The addition point 29 generates Trbst which is the difference between Tact and Tref. Trbst is input to the crank angle estimation unit 18 as the compression reaction force estimation value Tc.
The crank angle estimator 18 receives θm and Tc as inputs, and calculates a crank angle estimated value θc based on the relationship between the intake / exhaust valve opening / closing timing and the crank angle, which is obtained in advance by desktop examination using engine specifications.

Hereinafter, the crank angle estimation control according to the first embodiment will be described in detail.
FIG. 5 is a relationship diagram between the crank angle of the engine 1 and the intake / exhaust valve opening / closing timing.
As in the engine 1, in an engine in which the opening / closing timing of the intake / exhaust valve is interlocked with the rotational movement of the crank angle, as shown in FIG. 5, the valve opening section and the opening / closing timing of the intake valve and the exhaust valve are the cam shape and crank angle. It is determined uniformly according to.
In the first embodiment, the intake valve closing timing in the compression stroke (crank angle from compression top dead center TDC: θint) and the exhaust valve opening timing in the exhaust stroke (crank angle from compression top dead center TDC: θext) Paying attention, in the engine 1 having the relationship of the following formula (1), the engine 1 is rotated in the reverse direction.
θint <θext (1)

FIG. 6 is a relationship diagram between the combustion stroke of the engine 1 and the intake / exhaust valve opening / closing timing.
In a four-stroke engine such as the engine 1, the combustion stroke is one cycle at a crank angle of 720 °, and the combustion cycle proceeds in the order of intake → compression → expansion → exhaust. FIG. 6 shows the combustion cycle in a certain cylinder and the open / close state of the intake / exhaust valve during the rotational motion. The section in which the motor 5 directly connected to the engine 1 receives the reaction force is a state in which a differential pressure with reference to the atmospheric pressure is generated inside the rotating cylinder, that is, a section in which both the intake and exhaust valves are closed (all valves (Closed section) only. In FIG. 6, the closed section of the intake / exhaust valve is shown by a solid line, and the overlapping section corresponds to this. When expressed using the crank angle θint as the intake valve closing timing and the crank angle θext as the exhaust valve opening timing, the valve fully closed section is (θint + θext).

FIG. 7 is a relationship diagram between the crank angle of the engine 1 and the engine compression reaction force.
In FIG. 7, the vertical axis represents the reaction force [N · m] acting on the motor 5, and the horizontal axis represents the crank angle [deg]. The waveform is a waveform obtained by adding up reaction forces for each cylinder generated when the engine 1 (6-cylinder engine) is rotated by the motor 5 with the first clutch 6 engaged. At this time, the initial angle before the start of the rotational motion was an angle at which an arbitrary cylinder is positioned at the compression top dead center TDC. For the vertical axis, the torque acting in the opposite direction to the rotation direction of the motor 5 is the reaction force (positive value). If the right rotation is the forward rotation direction with respect to the vehicle traveling direction, the reaction force is left This is the rotational torque, and the reaction force with respect to the reverse rotation direction (left rotation) becomes the right rotation torque.

Normally, when the engine 1 is rotated in the forward rotation direction, a change in the in-cylinder pressure generated in the valve fully closed section represented by (θint + θext) acts on the motor 5 as a reaction force torque. This reaction force torque waveform has periodicity, and the cycle is a compression reaction force cycle θcyc calculated from one cycle of the combustion stroke and the number of cylinders. Further, from various engine specifications, the maximum peak value of the waveform is generated at a predetermined crank angle before compression top dead center TDC (maximum compression reaction force crank angle θmax).
On the other hand, when the engine 1 is rotated in the reverse rotation direction, it has a periodicity obtained from the compression reaction force cycle θcyc and the compression reaction force maximum crank angle θmax as in the normal rotation direction, but before reaching the first maximum peak. There is a scene in which a large reaction force is lost once (compression reaction force loss). In the crank angle estimation control of the first embodiment, the estimation accuracy of the crank angle is improved by detecting the sign inversion of the gradient of the reaction torque waveform.

FIG. 8 is a characteristic diagram of compression reaction force generated for each cylinder of the engine 1.
In FIG. 8, only the cylinders that actually generate the reaction force (existing in the valve fully closed section) with respect to the reaction torque applied to the motor 5 shown in FIG. 7 are extracted and applied to the motor 5 for each cylinder. The reaction torque is depicted. In the case of a six-cylinder engine, there are a total of three cylinders that generate reaction force in a section rotated about θcyc in the forward direction and the reverse direction from the initial position (compression TDC) similar to FIG. These cylinders are designated as cylinders # 1, # 2, and # 3, and the initial position at this time is the compression top dead center (TDC) of cylinder # 1.

When the engine 1 is rotated in the forward direction, the cylinder # 1 and the cylinder # 2 give a reaction force. The reaction force mainly due to the increase in the in-cylinder pressure in the compression stroke in the cylinder # 2 is dominant, and in addition to this, it is influenced by the reaction force due to the decrease in the in-cylinder pressure (negative pressure) in the exhaust stroke in the cylinder # 1. At this time, when the relationship expressed by the following equation (2) using θext, θcyc, and θmax is satisfied, the reaction force loss due to the exhaust valve opening in cylinder # 1 is the reaction force increase region (positive) in cylinder # 2. Occurs in the gradient region).
θext <(θcyc−θmax) (2)
However, when the formula (2) is not established as shown in FIG. 8, that is, when θext> (θcyc−θmax), after the reaction force peak in the cylinder # 2 is exceeded, that is, the gradient is negative. Because the reaction force loss (negative gradient) of cylinder # 1 occurs, since the gradient is negative in both cases, it is difficult to detect the compression reaction force loss.

On the other hand, when the engine 1 is rotated in the reverse direction, the cylinder # 1 and the cylinder # 3 give a reaction force, and the reaction force mainly due to the increase in the in-cylinder pressure in the expansion stroke in the cylinder # 3 is dominant. In addition to this, in addition to this, it is affected by the reaction force due to the decrease in the cylinder pressure (negative pressure) in the compression stroke in the cylinder # 1. Here, it should be noted that the notation of the combustion stroke in the reverse direction is aligned with the forward direction for convenience and is different from an actual physical phenomenon.
In the reverse rotation direction, when the relationship expressed by the following equation (3) using θint, θcyc, and θmax is established, the intake valve opening in cylinder # 1 (although the valve closing timing is normal in the normal rotation direction) The reaction force loss due to the valve opening in the reverse rotation direction) occurs in the reaction force increase region (positive gradient) in the cylinder # 3.
θint <(θcyc−θmax) (3)

In FIG. 8, because the engine specifications satisfy Equation (3), before the reaction force peak in cylinder # 3 is reached, that is, in a region where the gradient is positive, the gradient becomes negative due to the reaction force loss of cylinder # 1. Therefore, by detecting the sign inversion of the gradient, it is possible to easily detect the compression reaction force loss.
Since the sign reversal of the gradient of the motor reaction force occurs uniformly at the crank angle θint that becomes the intake valve closing timing, the crank angle when this reversal phenomenon (compression reaction force loss) is detected is set to θint. Thus, highly accurate crank angle estimation can be realized.
In the first embodiment, the engine having the relationship shown in the formula (1) is assumed, and the right sides of the formula (2) and the formula (3) are the same. In order to estimate the crank angle, the engine 1 is rotated in the reverse direction.

FIG. 9 is a compression reaction force characteristic diagram when the initial position is an arbitrary position that is not the compression top dead center.
In the same engine specifications as in FIG. 8, the cylinders that give the reaction force to the motor 5 when the engine 1 is idling from the stopped state are extracted as cylinder # 1, cylinder # 2, and cylinder # 3, respectively, and their combined reaction force is extracted. Torque is shown in the top row. However, in FIG. 9, the initial position is a position rotated by θinit from the compression top dead center of cylinder # 1.
In the case of FIG. 9, as in FIG. 8, reaction force is generated by the cylinder # 1 and the cylinder # 2 in the forward rotation direction. In this case, in addition to the equation (2), the sign inversion of the reaction torque gradient can be detected only when the relationship shown in the following equation (4) considering the initial position θinit is satisfied.
(θext−θinit) <(θcyc−θmax−θinit) (4)
Similarly, in the reverse rotation direction, the sign reversal of the gradient of the reaction torque can be detected when the relationship of the following equation (5) considering θinit in addition to the equation (3) is satisfied.
(θint + θinit) <(θcyc−θmax + θinit) (5)
As described above, even if the initial position is an arbitrary position, in the engine 1 having the specifications of Equation (1), the sign of the reaction torque gradient is reversed by rotating the engine 1 in the reverse direction. The detectable equation (5) is established, and the crank angle can be estimated with high accuracy.

FIG. 10 is a relationship diagram between the initial crank angle (ATDC conversion) and the maximum compression reaction force ratio.
In FIG. 10, the vertical axis represents the maximum compression reaction force ratio [−], and the horizontal axis represents the initial crank angle θinit (ATDC conversion). The horizontal axis represents the maximum compression reaction force ratio for each arbitrary step value in the compression reaction force cycle θcyc with the compression top dead center of any cylinder as a reference (zero point). The maximum compression reaction force ratio on the vertical axis indicates the ratio of the force acting on the motor torque shaft 4 at the pressure generated by the compression and expansion of the air inside the cylinder during engine rotation. Yes. The force acting on the motor torque shaft 4 is calculated for each cylinder by calculating the force acting on the motor torque shaft 4 based on the engine specifications such as the cylinder surface area, valve opening / closing timing, and the amount of rotation. Is the total. Further, in order to see the influence on the vibration immediately after the engine 1 is started, the rotation amount from the start of rotation is set to one cycle of θcyc. At this time, values obtained by normalizing the maximum value of the compression reaction force generated in each θinit with respect to the value of ATDC 0 ° are plotted.

As is clear from FIG. 10, there is a difference in the maximum compression reaction force ratio when the engine rotates to θcyc after engine start according to θinit, and the compression reaction force is the vibration excitation force generated immediately after engine start. Assuming that, there is a vibration suppression optimum crank angle θideal that is an initial crank angle effective for vibration suppression.
In the first embodiment, the crank angle is estimated quickly and accurately by the crank angle estimation control, and then the crank angle is controlled to θideal by the optimal crank angle control, thereby suppressing floor vibration at the time of restarting the engine. To reduce the sense of incongruity

FIG. 11 is a flowchart showing a specific processing flow of crank angle estimation control and optimum crank angle control according to the first embodiment. This process is executed, for example, during idle stop.
In step S1, it is detected that the vehicle is stopped (vehicle speed 0 km / h) and the engine 1 is stopped (engine speed 0 rpm).
In step S2, the first clutch 6 is engaged to maintain the stopped state, and the second clutch 7 is released to maintain the stopped state even during control.
In step S3, as the rotation angle command value θm * of the motor 1 necessary for crank angle estimation, a rotation angle at which the sign reversal of the gradient of the compression reaction force waveform acting on the motor 5 occurs reliably is set. θm * is a negative value for rotating the engine 1 in the reverse rotation direction, and is, for example, a value for two cycles of the compression reaction force cycle θcyc− (2 × θcyc). It should be noted that θm * is provided with a rate of change limit of more than a certain value in order to prevent vehicle vibration accompanying sudden rotation due to step input.

In step S4, the angle of the motor 5 is controlled so that the motor rotation angle θm follows θm *.
In step S5, the remaining angle obtained by dividing θm by θcyc is stored as the estimated crank angle value θc as the estimated crank angle value θcon before correction.
In step S6, it is determined whether or not a phenomenon has occurred in which the sign of the compression reaction force estimated value Tc is reversed. If YES, the process proceeds to step S7. If NO, the process returns to step S4.
In step S7, the deviation between the crank angle θint that is the intake valve closing timing and the previous value θcon_z of the estimated crank angle before correction is stored in θoff. Since θint is a positive value and θcon_z is a negative value, the deviation is obtained by adding both. Note that the initial value of θoff is 0.

In step S8, θc is a value obtained by subtracting θoff from θcon.
In step S9, θm * is reset for optimal crank angle control. Specifically, the difference value (θcyc−θint) between θcyc and θint, which is the rotation angle required to reach the top dead center, and the vibration suppression optimum crank angle θideal are subtracted from the previous value θm_z of the motor rotation angle. Let the value be a new θm *.
In step S10, the angle of the motor 5 is controlled so that θm follows the newly set θm *.
In step S11, it is determined whether or not θm has reached θm *, that is, whether or not the crank angle has reached θideal. If YES, this control is terminated, and if NO, the process returns to step S10.

FIG. 12 is a time chart showing the crank angle estimation operation of the first embodiment.
At time t1, since the stop state and the stop state of the engine 1 are detected, the motor controller 12 starts crank angle estimation control, and the crank angle estimation unit 18 starts estimation of the crank angle. The rotation angle command value θm * is a value that causes sign reversal in the gradient of the compression reaction force acting on the motor 5 when the engine 1 is rotated in the reverse direction, for example, a negative value that is twice the compression reaction force cycle θcyc ( -2 x θcyc).
In the section from time t1 to t2, the compression reaction force estimated value Tc does not change the sign of the gradient, so the crank angle estimated correction value θoff is not updated with the initial value 0 stored, and the crank angle estimated value θc is not corrected. The crank angle estimated value θcon, that is, the remainder angle obtained by dividing the motor rotation angle θm by θcyc is continuously calculated.

At time t2, since the sign reversal of the gradient of Tc was detected, the crank angle θint, which is the valve closing timing of the intake valve obtained in advance from a desk study using the engine specifications, was used to calculate θint and the estimated crank angle value before correction. The deviation from the previous value θcon_z is stored in θoff. Thereby, after time t2, highly accurate θc in which the deviation between θcon and the true crank angle value is corrected is obtained. At time t2, θm * for optimal crank angle control is reset. Specifically, with respect to the previous value θm_z of the motor rotation angle at the time of detecting the sign reversal of the gradient (time t2), the difference between θcyc and θint, which is the rotation angle required to reach top dead center, and vibration suppression A value obtained by subtracting the optimum crank angle θideal.
At time t3, since θm has reached θm *, that is, the crank angle has reached θideal, the optimal crank angle control is terminated. As a result, cranking of the engine 1 is performed from the vibration suppression optimal crank angle θideal when the engine is restarted, so that floor vibration during the engine restart can be suppressed and a sense of discomfort given to the occupant can be reduced.

In the first embodiment, the disturbance torque estimated value Trbst when the engine 1 is rotated in the reverse direction by the motor 5 is regarded as the compression reaction force of the engine 1 acting on the motor 5, and the Trbst, the motor rotation angle θm, and the crank angle are A crank angle estimated value θc is calculated based on the engine compression reaction force characteristic. By considering Trbst as the compression reaction force, the motor rotation angle θm (actually the remainder angle obtained by dividing θm by the period of the compression reaction force) when the compression reaction force loss occurs (the sign of the compression reaction force gradient is reversed) Therefore, it is possible to associate the motor rotation angle θm with the crank angle. If the correlation between θm and the crank angle can be established, the crank angle can be estimated from the sequentially detected θm.
In the crank angle estimation control according to the first embodiment, by detecting the compression reaction force loss that occurs mechanically in conjunction with the crank angle, the crank angle of the crank angle is compared with the conventional estimation method that depends on the detection variation of the crank angle sensor. The estimation accuracy can be improved. Generally, a resolver that detects the rotation angle of a motor has a higher resolution than a crank angle sensor. Therefore, by estimating the crank angle from θm, the crank angle can be accurately estimated in the motor controller 12 having no crank angle information. As a result, since the control accuracy of vibration suppression optimal crank angle control is improved, floor vibration at the time of engine restart can be reduced.

The first embodiment has the following effects.
(1) A crank angle estimation method for a hybrid vehicle using a motor 5 and an engine 1 as a power source, wherein the engine 5 is connected to the motor 5 and fuel injection and ignition to the engine 1 are stopped. When 1 is driven in the reverse direction and the motor rotation angle θm when the engine 1 is reverse is detected, the estimated disturbance torque Trbst acting on the motor 1 is calculated, and the sign of the Trbst gradient is reversed Is calculated from the motor rotation angle θm based on the relationship between the angle θm of the engine 1 and the crank angle θint when the intake valve of the cylinder # 1 of the engine 1 is opened.
Therefore, it is possible to improve the estimation accuracy of the crank angle by detecting the sign inversion of the gradient of the compression reaction force generated mechanically in conjunction with the crank angle and associating the crank angle with θm. Further, by rotating the engine 1 in the reverse rotation direction, it is possible to facilitate detection of the compression reaction force loss as compared with the case of rotating in the normal rotation direction. Furthermore, since the compression reaction force loss occurs before the compression reaction force reaches the first maximum peak, the time required for estimating the crank angle can be shortened.

(2) The crank angle θint from the compression top dead center TDC corresponding to the opening timing of the intake valve of the cylinder # 1 during the reverse rotation of the engine 1 is the crank angle from the TDC corresponding to the peak timing of the disturbance torque (θcyc -Θmax). That is, the relationship of Expression (3) is established for the engine 1.
Therefore, before the compression reaction force reaches its peak, that is, in the region where the gradient of the compression reaction force is positive, the compression reaction force is lost due to the intake valve opening, so that the sign inversion of the compression reaction force can be reliably generated.

(3) The crank angle θint from the compression top dead center TDC corresponding to the closing timing of the intake valve of the cylinder # 1 during the reverse rotation of the engine 1 is the opening of the exhaust valve of the cylinder # 1 during the normal rotation of the engine 1. It is smaller than the crank angle θext from the TDC corresponding to the timing. That is, the relationship of Expression (1) is established for the engine 1.
Therefore, the probability that the sign of the compression reaction force is reversed when the compression reaction force is lost can be increased as compared with the case where the engine 1 is rotated forward.

(4) Calculate the estimated crank angle θcon before correction from the motor rotation angle θm and the cycle of the compression reaction force of the engine 1, and calculate the crank angle θint when the intake valve of the cylinder # 1 of the engine 1 opens and the gradient of the disturbance torque The crank angle estimation correction value θoff is calculated from the deviation from the motor rotation angle when the sign is reversed, and the crank angle estimation value θc is calculated by correcting θcon with θoff.
Therefore, the crank angle can be estimated with high accuracy.

(5) Using the formula 5 Gp '(s) of the motor 5 that inputs the final motor torque command value Tfin * and outputs the motor speed ωm, the inverse 1 / Gp ( The disturbance torque estimated value Trbst is estimated by subtracting the reference motor torque Tref obtained by multiplying Tfin * by H (s) from the motor applied torque estimated value Tact multiplied by s) and the low-pass filter H (s).
Therefore, the disturbance torque acting on the motor 5 can be accurately estimated by using the inverse model of the controlled object (motor 5).

(6) The engine 1, the first clutch 6, the motor generator 5, the second clutch 7, and the rear wheels 2 and 2 are arranged in the order of arrangement of the transmission paths, and the motor controller 12 is in the engaged state of the first clutch 6 and the second A crank angle control method for a hybrid vehicle in which the crank angle of the engine 1 is stopped at the vibration suppression optimum crank angle by the motor generator 5 in the released state of the clutch 7, and the crank angle estimated value θc calculated by the crank angle estimating unit 18 Based on the above, the crank angle is stopped at the vibration suppression optimum crank angle.
Therefore, highly accurate optimum crank angle control can be realized, and floor vibration during engine restart can be reduced. Further, since the estimation time of the crank angle can be shortened, the crank angle can be made the vibration suppression optimum crank angle at an early stage. Thereby, even when the time from the start of the idle stop to the engine restart is short, the optimum crank angle control can be executed.

(7) A crank angle estimation device for a hybrid vehicle using the motor 5 and the engine 1 as a power source, wherein the engine 1 and the motor 5 are connected to each other, and the engine 1 and the motor 5 are connected. The motor controller 12 that drives the motor 5 in the direction in which the engine 1 reverses while the fuel injection and ignition to 1 are stopped, the resolver 14 that detects the rotation angle θm of the motor 1, and the estimated disturbance torque Trbst of the motor 5 Based on the relationship between the disturbance torque estimator to be calculated (filter blocks 27 and 28), θm when the sign of the Trbst gradient is inverted, and the crank angle θint when the intake valve of the predetermined cylinder # 1 of the engine 1 opens And a crank angle estimating unit 18 for calculating a crank angle estimated value θc from the motor rotation angle θm.
Therefore, it is possible to improve the estimation accuracy of the crank angle by detecting the sign inversion of the gradient of the compression reaction force generated mechanically in conjunction with the crank angle and associating the crank angle with θm. Further, by rotating the engine 1 in the reverse rotation direction, it is possible to facilitate detection of the compression reaction force loss as compared with the case of rotating in the normal rotation direction. Furthermore, since the compression reaction force loss occurs before the compression reaction force reaches the first maximum peak, the time required for estimating the crank angle can be shortened.

(Other embodiments)
As mentioned above, although the form for implementing this invention was demonstrated based on embodiment, the concrete structure of this invention is not limited to embodiment, The design change of the range which does not deviate from the summary of invention And the like are included in the present invention.
For example, the second clutch 7 may be configured such that the transmission torque capacity can be changed by continuously engaging and releasing a plurality of friction elements of the automatic transmission 3. The automatic transmission 3 may be a continuously variable transmission.
In FIG. 4, Tc (Trbst) output from the addition point 29 may be filtered by a notch filter to remove the frequency component of the torque ripple of the motor 5. Alternatively, Tc may be filtered with a low pass filter to remove high frequency components. Thereby, the estimation dispersion | variation resulting from a torque ripple, measurement noise, etc. can be reduced.

1 engine
2 Rear wheel (drive wheel)
5 Motor generator
6 First clutch
7 Second clutch
12 Motor controller (motor controller)
13 Crank angle sensor
14 Resolver (motor rotation angle detector)
18 Crank angle estimator
27 Filter block (disturbance torque estimation unit)
28 Filter block (disturbance torque estimation unit)

Claims (7)

A method for estimating a crank angle of a hybrid vehicle using a motor and an engine as power sources,
Connecting the engine and the motor, driving the motor in a direction in which the engine reverses in a state where fuel injection and ignition to the engine are stopped;
Detecting or estimating a motor rotation angle when the engine is rotating in reverse, and estimating a disturbance torque acting on the motor;
Based on the relationship between the motor rotation angle when the sign of the disturbance torque gradient is reversed and the crank angle when the intake valve of the predetermined cylinder of the engine opens, a crank angle estimation value is calculated from the motor rotation angle. Crank angle estimation method for hybrid vehicle. The crank angle estimation method for a hybrid vehicle according to claim 1,
A hybrid vehicle in which the crank angle from the compression top dead center corresponding to the opening timing of the intake valve at the time of reverse rotation of the engine is smaller than the crank angle from the compression top dead center corresponding to the peak timing of the disturbance torque Crank angle estimation method. The crank angle estimation method for a hybrid vehicle according to claim 2,
The crank angle from the compression top dead center corresponding to the closing timing of the intake valve during reverse rotation of the engine is the crank angle from the compression top dead center corresponding to the valve opening timing of the exhaust valve during normal rotation of the engine. Crank angle estimation method for hybrid vehicle smaller than The crank angle estimation method for a hybrid vehicle according to any one of claims 1 to 3,
Calculate a pre-correction crank angle estimated value from the motor rotation angle and the cycle of the compression reaction force of the engine,
A crank angle estimation correction value is calculated from a deviation between the crank angle when the intake valve of the engine is opened and the motor rotation angle when the sign of the gradient of the disturbance torque is reversed,
A crank angle estimation method for a hybrid vehicle, wherein the crank angle estimation value is calculated by correcting the crank angle estimation value before correction with the crank angle estimation correction value. The crank angle estimation method for a hybrid vehicle according to any one of claims 1 to 4,
The motor torque command value is input to the motor torque command value and the motor torque command value is used to calculate the motor torque command value from a value obtained by multiplying the motor rotation speed by the inverse of the formula model and a low-pass filter. A method for estimating a crank angle of a hybrid vehicle, wherein the disturbance torque is estimated by subtracting a value multiplied by the low-pass filter. The engine, the first clutch, the motor, the second clutch, and the drive wheels are arranged in the transmission path arrangement order,
A method for controlling a crank angle of a hybrid vehicle, wherein a motor controller stops a crank angle of the engine at a predetermined optimum crank angle by the motor when the first clutch is engaged and the second clutch is released. ,
A crank angle control method for a hybrid vehicle that stops the crank angle of the engine at the optimum crank angle based on a crank angle estimation value calculated using the crank angle estimation method according to any one of claims 1 to 5. A crank angle estimation device for a hybrid vehicle using a motor and an engine as power sources,
A clutch connecting the engine and the motor;
A motor control unit configured to drive the motor in a reverse direction of the engine in a state where the engine and the motor are coupled and fuel injection and ignition to the engine are stopped;
A motor rotation angle detector for detecting the rotation angle of the motor;
A disturbance torque estimating unit for estimating a disturbance torque acting on the motor;
Based on the relationship between the motor rotation angle when the sign of the disturbance torque gradient is inverted and the crank angle when the intake valve of the predetermined cylinder of the engine opens, a crank angle estimation value is calculated from the motor rotation angle. A crank angle estimation unit;
A crank angle estimation device for a hybrid vehicle comprising:

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