JP2009024638A - Vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further suitably suppress a torque variation in an internal combustion engine. <P>SOLUTION: A vibration control device (100) includes: a predicting means (100) for predicting at least either a first torque variation caused by combustion in a combustion chamber of an internal combustion engine (200), or a second torque variation caused by air compression in the combustion chamber; and a control means (100) for controlling vibration over the internal combustion engine so that at least either the first torque variation or the second torque variation is offset or suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of a vibration damping control device for suppressing torque fluctuation of an internal combustion engine such as an engine.

  In the technical field of an internal combustion engine such as an engine, in order to suppress torque fluctuation (that is, torque vibration) of the internal combustion engine, a torque having a phase opposite to the torque fluctuation is output from an electric motor or the like. A technique for canceling or suppressing (hereinafter, such a technique is referred to as “vibration control”) is known. For example, according to the technique disclosed in Patent Document 1, an internal combustion engine that cannot directly output torque from an electric motor to an output shaft of the internal combustion engine (for example, an output shaft of the internal combustion engine via a planetary gear mechanism). Thus, the torque fluctuation can be canceled or suppressed for the internal combustion engine of the type in which the generator and the motor are connected.

JP 2006-67655 A

  In such a technique, the torque fluctuation is uniquely calculated based on the rotational speed and crank angle of the internal combustion engine. That is, if the rotation speed of the internal combustion engine is the same, the torque fluctuation is calculated by assuming that the torque fluctuation is also the same. However, even if the rotational speed, torque and output of the internal combustion engine are the same, due to differences in the operation line of the internal combustion engine (for example, whether it is operating on the output line or operating on the fuel consumption line, etc.) Depending on the operating conditions of the internal combustion engine. For this reason, even if the rotation speed of the internal combustion engine is the same, it is assumed that the torque fluctuation is different. For this reason, the technique for calculating the torque fluctuation based on the rotational speed and the crank angle described above includes a technical problem that the torque fluctuation cannot be canceled or suppressed appropriately.

  On the other hand, in order to solve the above-mentioned problem, there is also a technique for offsetting or suppressing the torque fluctuation by measuring the actually generated torque fluctuation and performing the measured torque fluctuation by feedback control. . However, since it is necessary to perform feedback control after measuring the actual torque fluctuation, there is a technical problem that the torque fluctuation cannot be canceled or suppressed suitably or completely. .

  The present invention has been made in view of, for example, the above-described conventional problems, and an object of the present invention is to provide a vibration suppression control device that makes it possible to more suitably suppress, for example, torque fluctuations of an internal combustion engine.

  In order to solve the above problem, the vibration suppression control device of the present invention provides a first torque fluctuation caused by combustion in the combustion chamber of the internal combustion engine and a second torque caused by air compression in the combustion chamber. Predicting means for predicting at least one of fluctuations, and controlling the internal combustion engine so that at least one of the first torque fluctuation and the second torque fluctuation predicted by the predicting means is offset or suppressed. Control means for performing vibration control.

  According to the vibration suppression control device of the present invention, torque fluctuations calculated based on the above-described rotation speed and crank angle (in other words, torque fluctuations caused by hardware factors of the internal combustion engine, Apart from the fluctuation), at least one of the first torque fluctuation caused by combustion and the second torque fluctuation caused by air compression is predicted. As a result, vibration suppression control is performed so that at least one of the predicted first torque fluctuation and second torque fluctuation is canceled or suppressed.

  Here, the first torque fluctuation caused by the combustion and the second torque fluctuation caused by the air compression are torque fluctuations that change according to the operating conditions of the internal combustion engine. Even if the operating conditions of the internal combustion engine differ due to the difference in torque, torque fluctuations that change in accordance with the different operating conditions can be offset or suppressed appropriately. Thereby, compared with the technique which cancels or suppresses the torque fluctuation calculated based on the rotation speed and the crank angle, the torque fluctuation generated in the internal combustion engine can be canceled or suppressed more suitably. .

  In addition, since at least one of the first torque fluctuation and the second torque fluctuation is predicted in advance, vibration suppression control can be performed by so-called feedforward control. For this reason, compared with the technique which cancels or suppresses the actually measured torque fluctuation by the feedback control, the torque fluctuation generated in the internal combustion engine can be canceled or suppressed more suitably.

  Furthermore, in view of the fact that it is difficult to directly predict the torque fluctuation itself that changes according to the driving conditions, in the present invention, the factors of the torque fluctuation that changes according to the driving conditions are two factors (that is, Combustion and air compression), torque fluctuations that change according to operating conditions are predicted as first torque fluctuations and second torque fluctuations. As a result, it is possible to predict the torque fluctuation (that is, the first torque fluctuation and the second torque fluctuation) that change according to the operating conditions more appropriately and accurately. As a result, torque fluctuations generated in the internal combustion engine can be offset or suppressed more appropriately.

  In one aspect of the vibration damping control device of the present invention, the prediction means predicts the first torque fluctuation based on at least one of ignition timing, excess air ratio, and air-fuel ratio.

  According to this aspect, it is possible to predict the first torque fluctuation suitably and accurately.

  In the aspect of the vibration suppression control apparatus that predicts the first torque fluctuation based on at least one of the ignition timing, the excess air ratio, and the air-fuel ratio as described above, the prediction means includes the ignition timing, the excess air ratio, and the You may comprise so that the said 1st torque fluctuation | variation may be estimated using the map or numerical formula which shows matching with at least 1 of an air fuel ratio and the said 1st torque fluctuation | variation.

  If comprised in this way, a 1st torque fluctuation | variation can be estimated comparatively easily.

  In another aspect of the vibration damping control device of the present invention, the prediction means predicts the second torque fluctuation based on at least one of intake pipe pressure and intake valve closing timing.

  According to this aspect, it is possible to predict the second torque fluctuation suitably and accurately.

  In the aspect of the vibration suppression control apparatus that predicts the second torque fluctuation based on at least one of the intake pipe pressure and the intake valve closing timing as described above, the predicting means includes the intake pipe pressure and the intake valve close timing. You may comprise so that the said 2nd torque fluctuation | variation may be estimated using the map or numerical formula which shows matching with at least 1 and the said 2nd torque fluctuation | variation.

  If comprised in this way, a 2nd torque fluctuation | variation can be estimated comparatively easily.

  In another aspect of the vibration damping control device of the present invention, the predicting means predicts a third torque fluctuation generated due to at least one of a reciprocating inertia force and friction of a piston provided in the internal combustion engine, and the control means For the internal combustion engine such that an overall torque fluctuation obtained by adding up at least one of the first torque fluctuation and the second torque fluctuation and the third torque fluctuation is offset or suppressed. To control vibration.

  According to this aspect, in addition to the first torque fluctuation and the second torque fluctuation that change according to the operating condition, the third torque fluctuation that does not change according to the operating condition (in other words, torque caused by a hardware factor of the internal combustion engine) It is possible to cancel or suppress the overall torque fluctuation of the internal combustion engine as a whole in consideration of the fluctuation, that is, the torque fluctuation calculated based on the rotation speed and the crank angle described above. Thereby, the torque fluctuation which generate | occur | produces in an internal combustion engine can be canceled or suppressed more suitably.

  In the aspect of the vibration suppression control apparatus that predicts the third torque fluctuation as described above, the prediction means may be configured to predict the third torque fluctuation based on the rotational speed of the internal combustion engine.

  If comprised in this way, a 3rd torque fluctuation | variation can be estimated suitably and accurately.

  The operation and other advantages of the present invention will become more apparent from the embodiments described below.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(1) Basic Configuration First, a configuration of an embodiment according to a hybrid vehicle to which a control device of the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram conceptually showing the structure of the hybrid vehicle of this embodiment.

  In FIG. 1, a hybrid vehicle 10 includes a transmission mechanism 11, wheels 12, an ECU 100, an engine 200, a motor generator MG1 (hereinafter appropriately referred to as “MG1”), a motor generator MG2 (hereinafter appropriately referred to as “MG2”), power A split mechanism 300, an inverter 400, a battery 500, and an SOC sensor 510 are provided.

  Transmission mechanism 11 is a transmission shaft (in other words, an axle) for transmitting the power output from engine 200 and motor generator MG2 to the wheels.

  The wheels 12 are means for transmitting the power transmitted through the transmission mechanism 11 to the road surface. In FIG. 1, the left and right wheels are shown. There are a total of four.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like and is configured to be able to control the entire operation of the hybrid vehicle 10. It is an example of the “vibration control device” according to the invention.

  The engine 200 is a gasoline engine that is an example of an “internal combustion engine” according to the present invention, and functions as a main power source of the hybrid vehicle 10. The detailed configuration of the engine 200 will be described later.

  Motor generator MG1 is configured to function as a generator for charging battery 500 or supplying electric power to motor generator MG2, and further as an electric motor for assisting the driving force of engine 200.

  Motor generator MG2 is configured to function as an electric motor for assisting the power of engine 200 or as a generator for charging battery 500.

  The motor generator MG1 and the motor generator MG2 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. Prepare. However, other types of motor generators may be used.

  The power split mechanism 300 is a planetary gear mechanism including a sun gear, a planetary carrier, a pinion gear, and a ring gear (not shown). Among these gears, the rotation shaft of the sun gear on the inner periphery is connected to the motor generator MG1, and the rotation shaft of the ring gear on the outer periphery is connected to the motor generator MG2. The rotation shaft of the planetary carrier located between the sun gear and the ring gear is connected to the engine 200 (more specifically, the drive shaft of the engine 200). The rotation of the engine 200 is performed by the planetary carrier and further the pinion gear. The engine 200 is transmitted to the sun gear and the ring gear, and the power of the engine 200 is divided into two systems. In the hybrid vehicle 10, the rotating shaft of the ring gear is connected to the transmission mechanism 11 in the hybrid vehicle 10, and the driving force is transmitted to the wheels 12 through the transmission mechanism 11.

  Inverter 400 converts DC power extracted from battery 500 into AC power and supplies it to motor generator MG1 and motor generator MG2, and also converts AC power generated by motor generator MG1 and motor generator MG2 into DC power. The battery 500 can be supplied. The inverter 400 may be configured as a part of a so-called PCU (Power Control Unit).

  The battery 500 is a rechargeable storage battery configured to be able to function as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2.

  The SOC sensor 510 is a sensor configured to be able to detect the remaining battery level that represents the state of charge of the battery 500. The SOC sensor 510 is electrically connected to the ECU 100, and the SOC value of the battery 500 detected by the SOC sensor 510 is always grasped by the ECU 100.

  Next, referring to FIG. 2, the configuration of the main part of engine 200 will be described with a part of the operation thereof. Here, FIG. 2 is a schematic diagram of the engine 200. In FIG. 2, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof is omitted as appropriate.

  The engine 200 combusts the air-fuel mixture through an ignition operation by an ignition device 202 in which a part of an ignition plug (not shown) is exposed in a combustion chamber in the cylinder 201, and is generated in accordance with an explosion force caused by the combustion. The reciprocating motion of the piston 203 can be converted into the rotational motion of the crankshaft 205 via the connecting rod 204. A crank position sensor 206 that detects the rotational position (ie, crank angle) of the crankshaft 205 is installed in the vicinity of the crankshaft 205. The crank position sensor 206 is electrically connected to the ECU 100, and the ECU 100 is configured to be able to control the ignition timing and the like of the ignition device 202 based on the crank angle detected by the crank position sensor 206. Yes.

  Below, the principal part structure of the engine 200 is demonstrated with a part of the operation | movement.

  At the time of fuel combustion in the cylinder 201, the air sucked from the outside passes through the intake pipe 207 and is mixed with the fuel injected from the injector 214 at the intake port 213 to become the above-mentioned air-fuel mixture. The fuel is stored in the fuel tank 215 and is pumped and supplied to the injector 214 via the delivery pipe 216 by the action of the low pressure pump 217. The injector 214 is electrically connected to the ECU 100, and is configured to be able to inject the supplied fuel into the intake port 213 according to the control of the ECU 100. Incidentally, the form of the injection means for injecting the fuel does not have to adopt a so-called intake port injector configuration as shown in the figure. For example, the pressure of the fuel pumped by the low pressure pump is further increased by the high pressure pump, You may have forms, such as what is called a direct injection injector etc. comprised so that a fuel could be directly injected in the cylinder 201 inside.

  The communication state between the inside of the cylinder 201 and the intake pipe 207 is controlled by opening and closing the intake valve 218. The air-fuel mixture combusted inside the cylinder 201 becomes exhaust and is led to the exhaust pipe 221 via the exhaust port 220 when the exhaust valve 219 that opens and closes in conjunction with the opening and closing of the intake valve 218 is opened.

  A cleaner 208 is disposed on the intake pipe 207 to purify air sucked from the outside. An air flow meter 209 is further disposed on the downstream side (cylinder side) of the cleaner 208. The air flow meter 209 has a form called a hot wire type, and is configured to be able to directly detect the mass flow rate of the sucked air. The air flow meter 209 is electrically connected to the ECU 100, and the detected mass flow rate of the intake air is constantly grasped by the ECU 100.

  A throttle valve 210 that adjusts the amount of intake air related to the air sucked into the cylinder 201 is disposed downstream of the air flow meter 209 in the intake pipe 207. A throttle position sensor 212 is electrically connected to the throttle valve 210, and is configured to be able to detect a throttle angle that is the opening degree.

  The slot valve motor 211 is a motor that is electrically connected to the ECU 100 and configured to drive the throttle valve 210. The ECU 100 is configured to be able to control the driving state of the throttle valve motor 211 based on the accelerator opening detected by the accelerator position sensor 800 described above. (Corner) is controlled.

  The throttle valve 210 is a kind of electronically controlled throttle valve as described above, and the throttle opening degree can be controlled by the ECU 100 regardless of the driver's intention (that is, the accelerator opening degree).

  A three-way catalyst 223 is installed in the exhaust pipe 221. The three-way catalyst 223 is a catalyst capable of purifying CO (carbon monoxide), HC (hydrocarbon), and NOx (nitrogen oxide) discharged from the engine 200, respectively. An air-fuel ratio sensor 222 is disposed on the exhaust pipe 221 upstream of the three-way catalyst 223. The air-fuel ratio sensor 222 is configured to detect the air-fuel ratio of the engine 200 from the exhaust gas discharged through the exhaust port 220. The air-fuel ratio sensor 222 is electrically connected to the ECU 100, and the detected air-fuel ratio is constantly grasped by the ECU 100.

  In addition, a temperature sensor 224 for detecting the temperature of the cooling water for cooling the engine 200 is disposed in the water jacket installed in the cylinder block that houses the cylinder 201. The temperature sensor 224 is electrically connected to the ECU 100, and the detected cooling water temperature is constantly grasped by the ECU 100.

  Note that at least a part of the operating conditions of the engine 200 described above are measured by the ECU 100 for vibration suppression control, which will be described in detail later. Specifically, the ignition timing (ignition timing) SA in the ignition device 202, the air-fuel ratio A / F, the intake pipe pressure Pm that is the output of a pressure sensor (not shown) installed in the intake pipe 207, and the intake valve 218 are closed. The intake valve closing timing IVC, which is the timing to be performed, is measured by the ECU 100. The ECU 100 is configured to be able to calculate the rotational speed Nm of the engine 200 based on the rotational position of the crankshaft 205.

(2) Basic Operation of Hybrid Vehicle 10 In the hybrid vehicle 10 of FIG. 1, the power distribution of the motor generator MG1, which functions mainly as a generator, the motor generator MG2 which functions mainly as an electric motor, and the engine 200 is divided into an ECU 100 and a power split. Controlled by the mechanism 300, the running state is controlled. Below, operation | movement of the hybrid vehicle 10 according to several situations is demonstrated.

(2-1) When Starting For example, when starting the hybrid vehicle 10, the motor generator MG2 is driven as an electric motor using the electric energy of the battery 500. Engine 200 is cranked by the power of motor generator MG2, and engine 200 is started.

(2-2) Starting At the time of starting, two types of modes can be adopted depending on the storage state of the battery 500 based on the output signal of the SOC sensor 510. For example, at the time of normal start (that is, SOC is good), since it is not necessary to charge battery 500 by motor generator MG1, engine 200 starts only for warm-up, and hybrid vehicle 10 The vehicle starts with the power of the generator MG2. On the other hand, when the state of charge is not good (that is, the SOC is lowered), motor generator MG1 functions as a generator by the power of engine 200, and battery 500 is charged.

(2-3) During light load traveling For example, when traveling at a low speed or down a gentle slope, the efficiency of the engine 200 is relatively poor, and fuel injection through the injector 214 is stopped. Engine 200 is stopped and hybrid vehicle 10 travels only with the power from motor generator MG2. At this time, if the SOC is lowered, engine 200 starts to drive motor generator MG1, and battery 500 is charged by motor generator MG1.

(2-4) Normal Traveling In a driving region where the fuel efficiency or combustion efficiency of the engine 200 is relatively good, the hybrid vehicle 10 travels mainly by the power of the engine 200. At this time, the power of the engine 200 is divided into two systems by the power split mechanism 300, one of which is transmitted to the wheels 12 via the direct shaft, the main power shaft and the transmission mechanism 11, and the other drives the motor generator MG1. To be used for power generation. Furthermore, motor generator MG2 is driven by the generated electric power, and the power of engine 200 is assisted by motor generator MG2. At this time, if the SOC is lowered, the output of engine 200 is increased, and a part of the electric power generated by motor generator MG1 is charged to battery 500.

(2-5) During braking When deceleration is performed, the motor generator MG2 is rotated by the power transmitted from the wheels 12 via the transmission mechanism 11 to operate as a generator. Thereby, the kinetic energy of the wheel 12 is converted into electric energy, and so-called “regeneration” is performed in which the battery 500 is charged.

(3) Basic Control of Engine 200 Next, basic control operation of the engine 200 will be described. ECU 100 repeatedly calculates an engine request output, which is an output required for engine 200, at a constant cycle. At this time, the ECU 100 determines the current accelerator opening and vehicle speed from a map stored in advance in a ROM based on an accelerator opening detected by an accelerator position sensor (not shown) and a vehicle speed detected by a vehicle speed sensor (not shown). The corresponding output shaft torque (torque to be output to the transmission mechanism 11) is calculated.

  Further, ECU 100 obtains the required power generation amount based on the output signal of SOC sensor 510, and corrects the output shaft torque with reference to the required power generation amount and the required amounts of various auxiliary devices (such as an air conditioner and power steering). Thus, the engine required output is calculated. It should be noted that the calculation method of the engine required output may be as executed in a known hybrid vehicle, and the details thereof may be variously changed as necessary.

(4) First Operation Example of Vibration Control of Engine 200 Next, with reference to FIG. 3 to FIG. 5, vibration control of the engine 200 (that is, control unique to the hybrid vehicle 10 according to the present embodiment (that is, A first operation example of torque fluctuation suppression control will be described. FIG. 3 is a flowchart conceptually showing a flow of the first operation example of the vibration damping control of the engine 200 in the hybrid vehicle 10 according to this embodiment, and FIG. 4 is a torque generated due to combustion. 5 is a graph showing torque fluctuations caused by fluctuations, reciprocating inertia force and friction, and torque fluctuations as a whole of the engine 200. FIG. 5 shows the engine 200 when the engine speed and torque are the same. 6 is a graph showing the torque when the combustion state (specifically, the ignition timing SA) is different.

  As shown in FIG. 3, first, a parameter indicating the current driving state is acquired based on outputs from various sensors provided in the hybrid vehicle 10 by the operation of the ECU 100 (step S101). Specifically, the ignition timing SA, the air-fuel ratio A / F, the intake pipe pressure Pm, the intake valve closing timing IVC, and the rotation speed Nm are acquired by the ECU 100.

  Thereafter, torque fluctuations caused by combustion in the engine 200 are predicted by the operation of the ECU 100 based on the ignition timing SA and the air-fuel ratio A / F among the parameters indicating the current operating state acquired in step S101. (Step S102). This prediction operation is performed using a map or a mathematical expression showing the correspondence between the ignition timing SA and the air-fuel ratio A / F and the torque fluctuation generated due to the combustion in the engine 200.

  Subsequently, the operation of the ECU 100 is caused by the reciprocating inertia force and friction (friction) of the piston 203 in the engine 200 based on the rotation speed Nm among the parameters indicating the current operating state acquired in step S101. Torque fluctuation is predicted (step S103). That is, the torque fluctuation resulting from the engine 200 as hardware is predicted. This prediction operation is performed using a map or a mathematical expression showing the correspondence between the rotational speed Nm and the reciprocating inertia force of the piston 203 in the engine 200 and the torque fluctuation generated due to the friction.

  Note that torque fluctuations caused by reciprocal inertia and friction (friction) differ from torque fluctuations caused by combustion, depending on the operating conditions of the engine 200 (specifically, the rotational speed Nm). Will not change. Therefore, by using the rotation speed Nm, it is possible to appropriately predict the torque fluctuation caused by the reciprocating inertia force and the friction (friction).

  Thereafter, the operation of the ECU 100 calculates a damping gain that takes into account the torque fluctuation predicted in step S102 and the torque fluctuation predicted in step S103 (step S104). The damping gain is a parameter for controlling the motor generator MG2 that applies torque for performing damping control. In other words, the vibration suppression gain substantially applies torque from the motor generator MG2 to the engine 200 (specifically, the drive shaft of the engine 200) that can cancel or suppress torque fluctuation. Are control parameters input to the motor generator MG2.

  Thereafter, vibration suppression control is performed based on the vibration suppression gain calculated in step S104 under the control of the ECU 100 (step S105). That is, the torque for canceling or suppressing the torque fluctuation of the engine 200 as a whole in which the torque fluctuation predicted in step S103 is added to the torque fluctuation predicted in step S102 (specifically, the engine 200 as a whole). Torque from the motor generator MG2 is applied to the engine 200 (specifically, the drive shaft of the engine 200).

  Specifically, the torque fluctuation generated due to combustion in the engine 200 shown in the upper part of FIG. 4 is generated due to the reciprocating inertia force and friction (friction) of the piston 203 in the engine 200 shown in the middle part of FIG. The torque for canceling or suppressing the torque fluctuation of the engine 200 as a whole shown in the lower part of FIG. 4 in consideration of the torque fluctuation (specifically, the torque having the opposite phase to the torque fluctuation shown in the lower part of FIG. 4) Is added to engine 200 from motor generator MG2.

  Here, as shown in FIG. 5, the torque fluctuation generated due to the combustion in engine 200 changes according to the operating condition of engine 200. For example, if the ignition timing SA is changed under the condition that the engine speed Nm, torque, and output are the same, as shown in FIG. 3, the torque peak value and the timing for taking the peak value (in other words, , Phase) is changing. Therefore, if the torque fluctuation calculated based on the rotational speed Nm and the crank angle is only canceled or suppressed as in the background art described above, the torque fluctuation that changes according to the operating condition of the engine 200 is suitable. Therefore, it is impossible to cancel or suppress the torque fluctuation of the engine 200 as a whole. However, in the present embodiment, since the torque fluctuation that changes according to the operating conditions is predicted in this way, the operating conditions of the engine 200 (for example, the above-described ignition timing SA, air-fuel ratio A / F, etc.) are different. Even if it becomes a thing, the torque fluctuation | variation which changes according to this different driving | running condition can be canceled or suppressed suitably. Thereby, the engine is compared with the technology that cancels or suppresses only the torque fluctuation (in other words, the torque fluctuation predicted in step S103) calculated based on the rotational speed Nm and the crank angle in the background art described above. The torque fluctuation generated in 200 can be offset or suppressed more suitably.

  In addition, since the torque fluctuation generated due to the combustion in the engine 200 is predicted in advance, vibration suppression control can be performed by so-called feedforward control. For this reason, compared with the technique which cancels or suppresses the actually measured torque fluctuation by the feedback control, the torque fluctuation generated in the engine 200 can be canceled or suppressed more suitably.

  Furthermore, since the torque fluctuation of the engine 200 can be canceled or suppressed suitably, the inconvenience that the torque of the engine 200 fluctuates unnecessarily or unintentionally can be suitably prevented. Thereby, the hybrid vehicle 10 can be controlled so that the efficiency of the hybrid system is optimized (for example, the charge / discharge balance is matched).

  From the viewpoint of canceling or suppressing torque fluctuations that vary according to operating conditions, the torque fluctuations generated due to the reciprocating inertia force and friction of the piston 203 in the engine 200 described above do not necessarily have to be predicted. . However, from the viewpoint of more preferably canceling out or suppressing the torque fluctuation of the engine 200 as a whole, as described above, the torque fluctuation generated due to the reciprocating inertia force and friction of the piston 203 in the engine 200 is predicted. It is preferable.

  In the above description, the torque fluctuation generated due to the combustion in the engine 200 and the torque fluctuation generated due to the reciprocating inertia force and friction of the piston 203 in the engine 200 are predicted separately. However, using a map or a mathematical expression showing the correspondence between the ignition timing SA, the air-fuel ratio A / F, the rotational speed Nm, and the torque fluctuation of the engine 200 as a whole, combustion in the engine 200 and reciprocating inertia force of the piston 203 in the engine 200 In addition, it is possible to directly predict the torque fluctuation of the engine 200 as a whole considering each of the friction.

  In the above description, the torque fluctuation caused by the combustion in the engine 200 is predicted using both the ignition timing SA and the air-fuel ratio A / F. However, even if any one of the ignition timing SA and the air-fuel ratio A / F is used, the torque fluctuation generated due to the combustion in the engine 200 may be predicted. In this case, it is preferable to use a map or a mathematical expression that indicates a correspondence between any one of the ignition timing SA and the air-fuel ratio A / F and a torque fluctuation generated due to combustion in the engine 200. Furthermore, even when the torque fluctuation generated due to combustion in the engine 200 is predicted using both the ignition timing SA and the air-fuel ratio A / F, the ignition timing SA and the air-fuel ratio A / F The torque fluctuation generated due to the combustion in the engine 200 may be predicted using the addition value, the multiplication value, and other calculation values.

  Further, in the above description, the torque fluctuation generated due to the combustion in the engine 200 is predicted using the air-fuel ratio A / F. However, instead of the air-fuel ratio A / F, a torque fluctuation generated due to combustion in the engine 200 may be predicted using the excess air ratio λ.

  In the above description, the vibration suppression control in the hybrid vehicle 10 has been described. However, the above vibration suppression control is also applied to a vehicle other than the hybrid vehicle 10 (for example, a normal vehicle including only the engine 200). May be. It goes without saying that even in this case, the various effects described above can be enjoyed accordingly.

  In the above description, a configuration in which torque is applied to engine 200 from motor generator MG2 is used as an example in order to perform vibration suppression control. However, it goes without saying that other configurations (for example, various existing configurations used for damping control) may be used.

(5) Second Operation Example of Vibration Control of Engine 200 Next, a second operation example of the vibration suppression control in the hybrid vehicle 10 according to the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a flowchart conceptually showing a flow of the second operation example of the vibration suppression control of the engine 200 in the hybrid vehicle 10 according to the present embodiment. FIG. 7 shows the same engine speed and torque. 6 is a graph showing the torque when the air compression state (specifically, intake valve closing timing IVC) in engine 200 is different under the conditions.

  The same operations as those described with reference to FIG. 3 are denoted by the same step numbers, and detailed description thereof is omitted.

  As shown in FIG. 6, first, a parameter indicating the current driving state is acquired based on outputs from various sensors provided in the hybrid vehicle 10 by the operation of the ECU 100 (step S101).

  Thereafter, the actual compression ratio ε is predicted by the operation of the ECU 100 based on the intake valve closing timing IVC among the parameters indicating the current operating state acquired in step S101 (step S201).

  Thereafter, due to the operation of the ECU 100, the air compression in the engine 200 is caused based on the intake pipe pressure Pm and the actual compression ratio ε predicted in step S201 among the parameters indicating the current operating state acquired in step S101. The generated torque fluctuation is predicted (step S202). This prediction operation is performed using a map or a mathematical expression showing the correspondence between the intake pipe pressure Pm and the actual compression ratio ε and the torque fluctuation generated due to the air compression in the engine 200.

  Subsequently, the operation of the ECU 100 is caused by the reciprocating inertia force and friction (friction) of the piston 203 in the engine 200 based on the rotation speed Nm among the parameters indicating the current operating state acquired in step S101. The torque fluctuation to be performed is predicted (step S103).

  Thereafter, the operation of the ECU 100 calculates a damping gain considering the torque fluctuation predicted in step S202 and the torque fluctuation predicted in step S103 (step S104).

  Thereafter, vibration suppression control is performed based on the vibration suppression gain calculated in step S104 under the control of the ECU 100 (step S105). That is, the torque for canceling or suppressing the torque fluctuation of the engine 200 as a whole in which the torque fluctuation predicted in step S103 is added to the torque fluctuation predicted in step S202 (specifically, the engine 200 as a whole). Torque from the motor generator MG2 is applied to the engine 200 (specifically, the drive shaft of the engine 200).

  Here, as shown in FIG. 7, the torque fluctuation generated due to the air compression in engine 200 changes according to the operating conditions of engine 200. For example, if the intake valve closing timing IVC is changed under the conditions where the engine speed Nm, torque and output are the same, as shown in FIG. In other words, the phase) is changing. Therefore, if the torque fluctuation calculated based on the rotational speed Nm and the crank angle is only canceled or suppressed as in the background art described above, the torque fluctuation that changes according to the operating condition of the engine 200 is suitable. Therefore, it is impossible to cancel or suppress the torque fluctuation of the engine 200 as a whole. However, in the present embodiment, since the torque fluctuation that changes in accordance with the operating conditions is predicted in this way, the operating conditions of the engine 200 (for example, the intake valve closing timing IVC described above, etc.) are different. However, torque fluctuations that change according to the different operating conditions can be canceled or suppressed appropriately. Thereby, the engine is compared with the technology that cancels or suppresses only the torque fluctuation (in other words, the torque fluctuation predicted in step S103) calculated based on the rotational speed Nm and the crank angle in the background art described above. The torque fluctuation generated in 200 can be offset or suppressed more suitably.

  In addition, since the torque fluctuation generated due to the air compression in the engine 200 is predicted in advance, the vibration suppression control can be performed by so-called feedforward control. For this reason, compared with the technique which cancels or suppresses the actually measured torque fluctuation by the feedback control, the torque fluctuation generated in the engine 200 can be canceled or suppressed more suitably.

  Furthermore, since the torque fluctuation of the engine 200 can be canceled or suppressed suitably, the inconvenience that the torque of the engine 200 fluctuates unnecessarily or unintentionally can be suitably prevented. Thereby, the hybrid vehicle 10 can be controlled so that the efficiency of the hybrid system is optimized (for example, the charge / discharge balance is matched).

  Note that the operation described with reference to FIG. 3 and the operation described with reference to FIG. 6 may be combined. That is, torque fluctuations caused by combustion in engine 200, torque fluctuations caused by air compression in engine 200, and torque fluctuations caused by reciprocating inertia force and friction of piston 203 in engine 200 The vibration suppression control may be performed so as to cancel or suppress the torque fluctuation of the entire engine 200 in consideration of the above.

  In view of the fact that it is difficult to directly predict the torque fluctuation itself that changes according to the driving conditions, in the present embodiment, the factors of the torque fluctuation that changes according to the driving conditions are two factors (that is, , Combustion and air compression), and two types of torque fluctuations that change according to the operating conditions are predicted separately. As a result, torque fluctuations that change according to operating conditions (that is, torque fluctuations that occur due to combustion in engine 200 and torque fluctuations that occur due to air compression in engine 200) are predicted more appropriately and accurately. can do. As a result, torque fluctuations generated in engine 200 can be offset or suppressed more appropriately.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Is also included in the technical scope of the present invention.

It is a block diagram which shows notionally the composition of the hybrid vehicle of this embodiment. It is a schematic diagram of an engine. It is a flowchart which shows notionally the flow of the 1st operation example of the vibration suppression control of the engine in the hybrid vehicle which concerns on this embodiment. It is a graph which shows the torque fluctuation which arises due to combustion, the torque fluctuation which arises due to reciprocating inertia force and friction, and the torque fluctuation as the whole engine. It is a graph which shows a torque in case the engine speed and a torque are the same conditions, when the combustion state (specifically, ignition timing) in an engine differs. It is a flowchart which shows notionally the flow of the 2nd operation example of the vibration suppression control in the hybrid vehicle which concerns on this embodiment. It is a graph which shows a torque when the rotation speed of an engine and a torque are the same conditions, and the air compression state (specifically, intake valve closing timing) in an engine differs.

Explanation of symbols

10 Hybrid vehicle 100 ECU
200 Engine 300 Power split mechanism 400 Inverter 500 Battery MG1, MG2 Motor generator

Claims (7)

Predicting means for predicting at least one of a first torque fluctuation caused by combustion in the combustion chamber of the internal combustion engine and a second torque fluctuation caused by air compression in the combustion chamber;
Control means for performing vibration damping control on the internal combustion engine such that at least one of the first torque fluctuation and the second torque fluctuation predicted by the prediction means is canceled or suppressed. A vibration suppression control device.   2. The vibration damping control device according to claim 1, wherein the prediction unit predicts the first torque fluctuation based on at least one of an ignition timing, an excess air ratio, and an air-fuel ratio.   The predicting means predicts the first torque fluctuation using a map or a mathematical formula showing correspondence between at least one of the ignition timing, the excess air ratio, and the air-fuel ratio and the first torque fluctuation. The vibration suppression control device according to claim 2.   4. The vibration damping control according to claim 1, wherein the predicting unit predicts the second torque fluctuation based on at least one of an intake pipe pressure and an intake valve closing timing. 5. apparatus.   The predicting means predicts the second torque fluctuation using a map or a mathematical formula showing correspondence between at least one of the intake pipe pressure and the intake valve closing timing and the second torque fluctuation. The vibration suppression control device according to claim 4. The predicting means predicts a third torque fluctuation generated due to at least one of a reciprocating inertia force and friction of a piston provided in the internal combustion engine;
The control means controls the internal combustion engine so that a total torque fluctuation obtained by adding at least one of the first torque fluctuation and the second torque fluctuation and the third torque fluctuation is canceled or suppressed. The vibration suppression control device according to any one of claims 1 to 5, wherein vibration suppression control is performed on the engine.   The vibration control apparatus according to claim 6, wherein the prediction unit predicts the third torque fluctuation based on a rotation speed of the internal combustion engine.

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