JP2010111201A - Engine start control device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress torque pulsation while satisfying power restriction, and to avoid occurrence of any unintended torque pulsation in a vehicle equipped with an engine and a motor. <P>SOLUTION: An engine start control device includes: a first arithmetic means (30) which calculates the power restriction gain of a first motor on the basis of the power restriction value of a first motor (13, 18) determined according to performance of a battery (14) in starting the engine (11), a basic gain determined on the basis of a transmission function between the engine and the first motor, the detected number of revolutions of the motor and an engine pulsation base torque map; and a selection means (30) which selects a gain which is smaller between a basic damping gain specified by a basic damping gain map and the calculated power restriction gain on the basis of the detected number of revolutions of the engine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of an engine start control device and method for suppressing torque pulsation of an engine at the time of engine start in a vehicle including an engine and a motor such as a hybrid vehicle.

  As this type of device, for example, when the power supply from the battery is good, the torque pulsation caused by the rotation of the engine is suppressed, and the engine and motor are controlled to start the engine. An apparatus has been proposed that controls the engine and the motor so as to start the engine by prohibiting the suppression of torque pulsation when the power supply state is not good (see Patent Document 1).

  Alternatively, when starting the engine, the ignition start rotation speed is set to a rotation speed larger than the resonance rotation speed band, and the torque command of the motor MG1 is set from the vibration suppression torque map set as the execution map. Subsequently, torque limits Tmin and Tmax as upper and lower limits of torque that may be output from the motor MG2 are calculated based on the battery input / output limits Win, Wout, and the like. Subsequently, an apparatus for setting a torque command for the motor MG2 limited by the torque limits Tmin and Tmax has been proposed (see Patent Document 2).

  Alternatively, when the engine is started, a temporary correction torque as a torque for suppressing torque pulsation is obtained from a temporary correction torque setting map set in advance based on the crank angle, and is corrected to the obtained temporary correction torque. There has been proposed an apparatus for driving and controlling the motor MG2 by setting a torque command for the motor MG2 using a correction torque multiplied by a coefficient (see Patent Document 3).

  Alternatively, when the engine start instruction is given, a damping gain is set to be smaller as the elapsed time after the engine is stopped is shorter or the altitude is higher and the outside air pressure is lower. There has been proposed an apparatus for setting a motor torque command and motoring an engine using a product obtained by multiplying a damping torque to be suppressed by a damping gain (see Patent Document 4).

  Alternatively, an apparatus for setting a motor torque command as the sum of a reference torque set based on the target engine speed and target torque of the engine and a correction torque set based on the target speed and speed of the motor. It has been proposed (see Patent Document 5). Alternatively, at the time of starting the engine, vibration caused by torque pulsation generated in the crankshaft should be suppressed, so that the vibration caused by torque pulsation is suppressed by the damping torque from the motor MG1, and the required torque is output. An apparatus for controlling the motor MG1 and the motor MG2 has been proposed (see Patent Document 6).

  Alternatively, the motor MG1 detects the torque pulsation generated in the engine torque from the detection signals from the crank angle detection sensor and the engine water temperature detection sensor during the engine starting operation, and generates the damping torque in phase with the torque pulsation. Has been proposed (see Patent Document 7).

JP 2007-55435 A JP 2006-316663 A JP-A-2005-90307 JP 2007-137375 A JP 2005-45862 A JP 2008-162491 A Japanese Patent No. 3958220

  However, according to the background art described above, when the damping torque to be applied to the motor is limited by, for example, power limitation determined based on the performance of the battery, the waveform of the damping torque is different from the intended torque. Thus, there is a technical problem that torque pulsation of an unintended frequency may occur.

  The present invention has been made in view of the above-mentioned problems, for example, and provides an engine start control device and method capable of suppressing torque pulsation while satisfying power limitation and avoiding unintended torque pulsation. This is the issue.

  In order to solve the above problems, an engine start control device of the present invention is mounted on a vehicle including an engine and a first motor that are connected to each other via a damper, and a storage battery that can supply electric power to the first motor. A crank angle detecting means for detecting a crank angle of the engine; an engine speed that is the engine speed; and a rotation speed detecting means that detects a motor speed that is the speed of the first motor; Storage means for storing an engine pulsation base torque map capable of specifying pulsation torque caused by engine rotation, and a basic damping gain map determined according to resonance generated in a power transmission system including the damper, and the engine When starting the engine, the power limit value of the first motor determined according to the performance of the storage battery and the transmission between the engine and the first motor are determined. A first calculating means for calculating a power limit gain of the first motor based on a basic gain determined by a function, the detected motor rotational speed, and the stored engine pulsation base torque map; Selection means for selecting a smaller one of the basic damping gain specified by the stored basic damping gain map and the calculated power limit gain based on the detected engine speed; and the selection A second calculating means for calculating a damping torque by multiplying the detected gain by the engine pulsation torque specified on the basis of the detected crank angle and the stored engine pulsation base torque map; Setting means for setting the torque of the first motor based on a vibration torque; and the first so as to output the set torque. And control means for driving and controlling over data.

  According to the engine start control device of the present invention, the engine start control device is mounted on a vehicle including an engine such as a hybrid vehicle and a first motor, for example. In the vehicle, the engine and the first motor are connected to each other via a damper such as a torsional damper. Here, the “motor” is typically a motor for driving the vehicle, but may be a motor realized in, for example, a motor generator (motor generator). That is, it may mean a motor generator as long as it can function as a motor.

  The crank angle detection means detects the crank angle of the engine. The rotation speed detection means detects an engine rotation speed that is the rotation speed of the engine and a motor rotation speed that is the rotation speed of the first motor. The rotational speed detection means may directly detect the engine rotational speed and the motor rotational speed, or directly detect one rotational speed of the engine rotational speed and the motor rotational speed, and directly detect the other rotational speed. It may be estimated (that is, indirectly detected) based on the determined rotation speed. Alternatively, the rotational speed detection means may estimate the engine rotational speed and the motor rotational speed according to some physical quantity or parameter.

  For example, the storage means such as a non-volatile memory includes an engine pulsation base torque map that can identify pulsation torque caused by engine rotation, and a basic damping gain map that is determined according to resonance that occurs in a power transmission system including a damper. And store. Here, the engine pulsation base torque map is typically configured as a relationship between the pulsation torque and the crank angle of the engine. The basic vibration suppression gain map is configured as a relationship between the vibration suppression gain and the engine speed or a value obtained by dividing the engine speed by the motor speed.

  Such an engine pulsation base torque map and a basic damping gain map are obtained experimentally, empirically, or by simulation, for example, engine speed, motor speed, crank angle, power transmission system such as a damper or drive shaft. What is necessary is just to obtain | require the relationship between each of a characteristic and each pulsation torque of an engine, and to build based on this calculated | required relationship.

  The “power transmission system including the damper” means members such as a damper, a drive shaft, and a speed reducer for transmitting the driving force output from each of the engine and the first motor to the wheels.

  For example, the first calculation means configured to include a memory, a processor, and the like includes a power limit value of the first motor determined according to the performance of the storage battery when starting the engine, and a transmission between the engine and the first motor. Based on the basic gain determined by the function, the detected motor rotation speed, and the stored engine pulsation base torque map, the power limit gain of the first motor is calculated.

  Here, “when the engine is started” typically means that the normal combustion state has been obtained in the combustion chamber of the engine or the engine has completely exploded from the start of cranking of the engine. It means the period until the time. Furthermore, the normal combustion state is obtained or the engine is in a state of complete explosion from a point that is slightly later in time than the cranking start point or a predetermined minute time from the cranking start point. It may include a time point slightly later than a certain time point, a time point when a normal combustion state is obtained, or a time point when the engine is completely detonated to a time point after a predetermined minute time.

  Further, “based on the engine pulsation base torque map” means based on one of the engine pulsation base torques included in the engine pulsation base torque map. Here, “one engine pulsation base torque” is, for example, the maximum value of the engine pulsation base torque included in the engine pulsation base torque map.

  Note that the power limit gain of the first motor may be calculated in advance for a plurality of motor rotation speeds, and may be stored in the storage means as, for example, a power limit gain map.

  For example, the selection means configured to include a memory, a processor, and the like includes a basic damping gain specified by a stored basic damping gain map and a calculated power limit gain based on the detected engine speed. Select the smaller gain.

  For example, the second calculation means including a memory, a processor, etc. controls the selected gain by multiplying the detected crank angle and the engine pulsation torque specified based on the stored engine pulsation base torque map. Calculate the vibration torque. The “engine pulsation torque” is not limited to the engine pulsation base torque itself included in the engine pulsation base torque map, and may include a value obtained by performing some processing on the engine pulsation base torque.

  For example, the setting means including a memory, a processor, etc. sets the torque of the first motor based on the calculated vibration damping torque. For example, a control unit including a memory, a processor, and the like drives and controls the first motor so as to output a set torque.

  According to the research of the present inventor, in the current vibration suppression control performed to suppress the pulsation torque caused by the rotation of the engine, the vibration suppression torque to be added to the motor theoretically determined in advance is the storage battery. Therefore, there is a possibility that the damping torque as theoretically (that is, for example, intended by a designer or the like) is not added to the motor. Then, it turns out that the frequency of the pulsation torque caused by the rotation of the engine and the frequency of the damping torque generated by the motor are shifted, and torque fluctuation of an unintended frequency occurs, which may worsen the vibration of the vehicle. is doing.

  In the current damping control, the theoretical damping torque is based on the pulsation torque caused by the engine rotation, the basic gain determined by the transfer function between the engine and the motor, and the resonance generated in the damper and drive shaft. It is obtained by multiplying the corresponding damping gain.

  However, in the present invention, when the engine is started by the first calculation means, the power limit value of the first motor determined according to the performance of the storage battery and the basic function determined by the transfer function between the engine and the first motor. Based on the gain, the detected motor speed, and the stored engine pulsation base torque map, the power limit gain of the first motor is calculated.

  Subsequently, based on the detected engine speed and the detected motor speed by the selection means, the smaller one of the basic damping gain and the calculated power limit gain specified by the stored basic damping gain map The gain is selected.

  Subsequently, the damping torque is calculated by multiplying the selected gain by the detected crank angle and the engine pulsation torque specified based on the stored engine pulsation base torque map by the second calculation means.

  That is, in the present invention, when calculating the damping torque, a power limit gain calculated taking into account the power limit value of the first motor can be used, so that the theoretical damping torque can be applied to the first motor. Can be added. For this reason, torque pulsation can be suppressed while satisfying the power limit, and unintended torque pulsation can be avoided.

  In the present invention, as described above, the selection means specifies the calculated power limiting gain and the basic damping gain map determined according to the resonance generated in the power transmission system including the damper (that is, the first The smaller one of the basic damping gains (not including the power limit value of one motor) is selected. This is based on the consideration that if the basic damping gain is smaller than the power limiting gain, the power limiting value of the first motor will not be exceeded even if the basic damping gain is used.

  Thus, by using the smaller one of the power limiting gain and the basic damping gain for the calculation of damping torque, the torque pulsation can be effectively reduced while reducing the damping torque applied to the first motor. Can be suppressed. As a result, energy efficiency can be improved, which is very advantageous in practice.

  In one aspect of the engine start control device of the present invention, the vehicle has a power split means having a planetary gear mechanism, a second motor connected to a rotation shaft of an outer ring gear of the power split means, and a speed of the vehicle. The engine further includes speed detecting means for detecting, the engine is connected to the rotating shaft of the planetary carrier of the power split means via the damper, and the first motor rotates the sun gear of the power split means The rotation speed detecting means is connected to a shaft, and the planetary gear ratio which is the ratio of the detected speed, the detected engine rotation speed, and the number of teeth of the sun gear and the number of teeth of the outer ring gear. Based on the above, the motor rotation speed is detected.

  According to this aspect, even in a vehicle including the engine, the first and second motors, and the power split device, torque pulsation can be suppressed while satisfying the power limit, and occurrence of unintended torque pulsation can be avoided. .

  The vehicle further includes power split means, second motor, and speed detection means. For example, speed detection means such as a speed sensor detects the speed of the vehicle by detecting the rotational speed of the drive shaft, for example.

  The engine is connected to the rotating shaft of the planetary carrier of the power split means via a damper, the first motor is connected to the rotating shaft of the sun gear of the power split means, and the second motor is connected to the power split means. It is connected when the outer ring gear of the means rotates. In this aspect, the first motor is typically a motor realized by a motor / generator.

  The rotational speed detection means detects the motor rotational speed of the first motor based on the detected speed, the detected engine rotational speed, and the planetary gear ratio. Specifically, when the planetary gear ratio is ρ, the rotational speed detection means calculates the value obtained by multiplying the engine rotational speed by a coefficient of (1 + ρ) / ρ and the rotational speed of the drive shaft determined by the detected speed. The motor rotation speed is detected by obtaining a difference value from the value multiplied by (1 / ρ).

  In another aspect of the engine start control device of the present invention, the first calculation means sets the power limit value to the detected motor rotational speed and calculates the engine pulsation base torque in the stored engine pulsation base torque map. The power limit gain is calculated by dividing by a value obtained by multiplying the maximum value and the basic gain.

  According to this aspect, it is relatively easy to calculate the power limit gain that takes into account the power limit value of the first motor.

  The first computing means divides the power limit value by the value obtained by multiplying the detected motor rotation number by the maximum value of the engine pulsation base torque in the stored engine pulsation base torque map and the basic gain. Is calculated. More specifically, the first calculation means uses an expression of (power limit gain) = (power limit value) ÷ {(motor speed) × (maximum value of engine pulsation base torque) × (basic gain)}. To calculate the power limit gain.

  In order to solve the above-described problems, an engine start control method of the present invention is mounted on a vehicle including an engine and a first motor that are connected to each other via a damper, and a storage battery that can supply power to the first motor. A crank angle detecting means for detecting a crank angle of the engine; an engine speed that is the engine speed; and a rotation speed detecting means that detects a motor speed that is the speed of the first motor; An engine comprising an engine pulsation base torque map capable of specifying a pulsation torque caused by engine rotation, and a storage means for storing a basic damping gain map determined in accordance with resonance generated in a power transmission system including the damper. An engine start control method in a start control device, wherein the engine is determined according to the performance of the storage battery when starting the engine Based on a power limit value of one motor, a basic gain determined by a transfer function between the engine and the first motor, the detected motor speed, and the stored engine pulsation base torque map, Based on a first calculation step of calculating a power limit gain of the first motor and the detected engine speed, the basic damping gain specified by the stored basic damping gain map and the calculated A selection step of selecting a smaller one of the power limit gains, and multiplying the selected gain by the engine pulsation torque specified based on the detected crank angle and the stored engine pulsation base torque map. A second calculation step for calculating the damping torque and setting the torque of the first motor based on the calculated damping torque. A setting step of, to output the set torque, and a control step of driving and controlling the first motor.

  According to the engine start control method of the present invention, as in the engine start control device of the present invention described above, torque pulsation can be suppressed while satisfying the power limit, and unintended torque pulsation can be avoided.

  In the engine start control method of the present invention, various aspects of the above-described engine start control device of the present invention can be adopted.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, an embodiment according to an engine start control device of the present invention will be described with reference to the drawings.

<First Embodiment>
A first embodiment of the engine start control device of the present invention will be described with reference to FIGS. 1 to 8.

(Configuration of engine start control device)
First, a vehicle equipped with an engine start control device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the vehicle according to this embodiment.

  In FIG. 1, a vehicle 1 includes an engine 11, a torsional damper 12, a motor 13, a power storage device 14, a transmission (T / M) 15, a differential gear 16, a drive shaft 17, an ECU (Electronic Control Unit) 30, and a plurality of wheels. 40.

  Here, the “torsional damper 12”, the “motor 13”, and the “power storage device 14” according to the present embodiment are examples of the “damper”, the “first motor”, and the “storage battery” according to the present invention, respectively. . The “torsional damper 12”, “transmission 15”, “differential gear 16”, and “drive shaft 17” according to the present embodiment are examples of the “power transmission system” according to the present invention.

  The engine start control device according to the present embodiment detects a crank angle sensor 21 that detects a crank angle of the engine 11, a rotation speed sensor 22 that detects an engine rotation speed that is the rotation speed of the engine 11, and detects the speed of the vehicle 1. The vehicle speed sensor 23 is provided. Here, the “crank angle sensor 21”, “rotational speed sensor 22”, and “vehicle speed sensor 23” according to the present embodiment are respectively referred to as “crank angle detecting means”, “rotational speed detecting means”, and “ It is an example of “speed detection means”.

  The engine start control device is determined in accordance with (i) an engine pulsation torque base map (see FIG. 2) that can specify a pulsation torque caused by the rotation of the engine 11, and resonance generated in the torsional damper 12 and the drive shaft 17. And (ii) a power limit value of the motor 13 determined according to the performance of the power storage device 14 and a transfer function between the engine 11 and the motor 13. The power limit gain of the motor 13 is calculated based on the basic gain, the motor rotational speed that is the rotational speed of the motor 13, and the engine pulsation torque base map. (Iii) Based on the engine rotational speed, ECU 3 for selecting the smaller one of the basic vibration suppression gain and the calculated power limit gain specified by the vibration gain map Further comprising: a.

  The “ECU 30” according to the present embodiment is an example of the “storage unit”, “first calculation unit”, and “selection unit” according to the present invention. In this embodiment, a part of the ECU 30 for various electronic controls is used as a part of the engine start control device.

  The ECU 30 as a part of the engine start control device further detects (iv) the motor rotation speed based on the engine rotation speed detected by the rotation speed sensor 22. Here, when the speed reducer is not disposed between the engine 11 and the motor 13 as in the vehicle 1, the motor speed is equal to the engine speed. The “ECU 30” according to the present embodiment is another example of the “rotational speed detection unit” according to the present invention.

  The ECU 30 as a part of the engine start control device further selects the engine pulsation torque specified based on the detected crank angle from the engine pulsation base torque map (v) as a selected gain (ie, basic vibration suppression). (Vi) set the torque of the motor 13 based on the calculated damping torque, and (vii) output the set torque. The motor 13 is driven and controlled. Here, the “ECU 30” according to the present embodiment is an example of the “second arithmetic unit”, “setting unit”, and “control unit” according to the present invention.

(Engine start control process)
Next, engine start control processing executed by the ECU 30 in the engine start control device configured as described above will be described with reference to FIGS. 2 to 8. This engine start control process is executed mainly when starting the engine while the vehicle is running or when running is started.

  When the ECU 30 starts the engine 11, first, the ECU 13 determines the maximum value of the engine pulsation base torque included in the engine pulsation base torque map as shown in FIG. 2 and the performance of the power storage device 14. Based on the power limit value, the basic gain determined by the transfer function between the engine 11 and the motor 13, and the motor speed detected based on the engine speed detected by the speed sensor 22, the motor 13 Calculate the power limit gain.

  Specifically, the ECU 30 calculates the power limit gain using an equation of (power limit gain) = (motor power limit torque) / {(maximum value of engine pulsation base torque) × (basic gain)}. Here, the “motor power limit torque” is obtained by dividing the power limit value by the motor rotation speed. The relationship between the obtained motor power limit torque and the engine speed / motor speed is as shown in FIG. In the present embodiment, when the motor power limit torque is larger than the motor torque limit value Tml determined by the performance of the motor 13, the motor power limit torque is set to the motor torque limit value Tml.

  Further, the relationship between the power limit gain calculated by the ECU 30 and the engine speed / motor speed is as shown by a solid line in FIG. A dotted line in FIG. 5 represents a basic damping gain determined in accordance with resonance generated in the torsional damper 12 and the drive shaft 17 shown in FIG.

  FIG. 2 is a conceptual diagram showing an example of an engine pulsation base torque map showing the relationship between the engine pulsation base torque and the crank angle according to the present embodiment. The solid line in FIG. 2 indicates the engine pulsation base torque in the steady state of the engine 11, and the dotted line indicates the engine pulsation base torque in the transient state of the engine 11. Here, the “steady state” means a state where the amount of air taken into the engine 11 is stable. On the other hand, the “transient state” means a state where the amount of air sucked into the engine 11 is not stable. For example, the engine 11 during the period from the cranking start time of the engine 11 to the first top dead center is exceeded. Means state.

  As shown in FIG. 2, the engine pulsation base torque in the transient state indicated by the dotted line is smaller than the engine pulsation base torque in the steady state indicated by the solid line. This is because, in the transient state, for example, due to the low rotational speed of the engine 11, the intake air amount is not sufficient, and the torque due to the air compression reaction force is small.

  FIG. 3 is a conceptual diagram showing an example of a basic damping gain map showing the relationship between the basic damping gain and the engine speed according to the present embodiment. The “damper / drive shaft resonance region” in FIG. 3 is a region where the engine speed corresponds to, for example, 300 rpm to 600 rpm.

  FIG. 4 is a conceptual diagram showing an example of the relationship between the motor power limit torque and the engine speed according to the present embodiment. FIG. 5 is a conceptual diagram showing an example of the relationship between the power limit gain (or vibration suppression gain) and the engine speed according to the present embodiment. In this embodiment, since the engine speed and the motor speed are equal, the “engine speed” in FIGS. 4 and 5 may be read as “motor speed”.

  Next, the ECU 30 determines, based on the engine speed detected by the speed sensor 22, the basic damping gain specified by the basic damping gain map as shown in FIG. 3 and the calculated power limiting gain. Select the smaller gain. As shown in FIG. 5, in a region where the engine speed is relatively high, the basic damping gain indicated by the dotted line is smaller than the power limiting gain indicated by the solid line. Therefore, the power limit gain is selected in a region where the engine speed is relatively low, and the basic vibration suppression gain is selected in a region where the engine speed is relatively high.

  FIG. 6 shows the relationship between the smaller one of the basic damping gain and the power limit gain selected by the ECU 30 (hereinafter referred to as “motor limit gain” as appropriate) and the engine speed. FIG. 6 is a conceptual diagram showing an example of the relationship between the motor limit gain and the engine speed according to this embodiment.

  Next, based on the crank angle detected by the crank angle sensor 21, the ECU 30 calculates the damping torque by multiplying the engine pulsation torque specified by the engine pulsation base torque map by the selected motor limit gain.

  Here, a specific description will be given of a method in which the ECU 30 specifies the engine pulsation torque from the engine pulsation base torque map. As appropriate, the engine pulsation base torque indicated by a solid line in FIG. 2 is referred to as a “steady state map”, and the engine pulsation base torque indicated by a dotted line in FIG. 2 is referred to as a “transient map”. The engine pulsation base torque corresponding to the steady map is referred to as “steady engine pulsation base torque”, and the engine pulsation base torque corresponding to the transient map is referred to as “transient engine pulsation base torque”.

  In the period from the cranking start time of the engine 11 to exceeding the first top dead center, the ECU 30 specifies the transient engine pulsation base torque from the transient map based on the detected crank angle. Subsequently, the ECU 30 changes the initial crank angle (that is, the crank angle at the start of cranking) and the maximum value of the crank angle from the specified transient engine pulsation base torque to the specified transient engine pulsation base torque. The engine pulsation base torque is specified by subtracting the value multiplied by the ratio.

  More specifically, the ECU 30 uses the following equation: (engine pulsation torque) = (transient engine pulsation base torque) − (transient engine pulsation base torque) × (initial crank angle) ÷ (maximum crank angle). Specify the pulsation torque. The “maximum crank angle value” is a value obtained by dividing 720 by the number of cylinders of the engine 11.

  In the period from the time when the first top dead center is exceeded to the time when the second top dead center is exceeded, the ECU 30 determines, based on the detected crank angle, the steady engine pulsation base torque and the torque from each of the steady map and the transient map. Identify the transient engine pulsation base torque. Subsequently, the ECU 30 multiplies the difference between the specified transient engine pulsation base torque and the steady engine pulsation base torque by the ratio of the initial crank angle and the maximum crank angle to the identified steady engine pulsation base torque. The engine pulsation torque is specified by adding a value.

  More specifically, the ECU 30 determines (engine pulsation torque) = (steady engine pulsation base torque) + {(transient engine pulsation base torque) − (steady engine pulsation base torque)} × (initial crank angle) / (crank angle). The engine pulsation torque is specified using the equation (maximum value).

  In the period after the second top dead center is exceeded, the ECU 30 identifies the steady engine pulsation base torque from the steady map based on the detected crank angle, and determines the identified steady engine pulsation base torque. Use engine pulsation torque.

  The ECU 30 then sets the torque to be output by the motor 13 by adding the calculated damping torque to the motor torque. Subsequently, the ECU 30 drives and controls the motor 13 so as to output the set torque.

  Here, the damping torque added to the motor torque is as shown in FIG. As shown in FIG. 7, the damping torque added to the motor torque (“motor added torque” in FIG. 7) is between the upper limit value Tmlu and the lower limit value Tmll of the power limit torque of the motor 13. FIG. 7 is a conceptual diagram showing an example of the relationship between the damping torque and the crank angle according to the present embodiment.

  Next, the result of performing a frequency analysis on the damping torque applied to the motor 13 will be described with reference to FIG. FIG. 8 is a conceptual diagram showing an example of the frequency analysis result of the vibration damping torque according to this embodiment. The solid line in FIG. 8 indicates the damping torque applied to the motor 13, and the dotted line indicates the theoretical value of the damping torque (that is, the value when there is no power restriction determined according to the performance of the power storage device 14). Is shown.

  As shown in FIG. 8, the absolute value of the damping torque applied to the motor 13 is smaller than the theoretical value because the power limit value is taken into account, but it can be seen that the frequencies are the same. . For this reason, according to the engine start control device according to the present embodiment, it is possible to avoid the occurrence of unintended torque pulsation.

(Comparative example)
Next, a comparative example of the engine start control device according to the present embodiment will be described with reference to FIGS. 9 to 11.

  In the engine start control device according to the comparative example, the engine pulsation torque specified by, for example, the engine pulsation base torque map as shown in FIG. 2 is added to the basic gain and the basic damping gain map as shown in FIG. By multiplying the specified basic damping gain, the damping torque (see FIG. 9) applied to the motor 13 is calculated.

  Here, the calculated vibration damping torque is a vibration damping torque not taking into account the power limit value determined according to the performance of the power storage device 14 or the like. That is, the calculated damping torque is a theoretical value of the damping torque. FIG. 9 is a conceptual diagram showing an example of the relationship between the damping torque and the crank angle according to the comparative example.

  When the engine start control device according to the comparative example determines the damping torque to be actually applied to the motor 13, it is calculated by comparing the calculated damping torque with the torque corresponding to the power limit value. When the damping torque exceeds the torque corresponding to the power limit value, the torque corresponding to the power limit value is determined as the damping torque to be added to the motor 13.

  Therefore, as shown in FIG. 10, in the region where the calculated vibration damping torque is larger than the upper limit value Tmlu of the power limit torque and the region smaller than the lower limit value Tmll, the vibration damping added to the motor 13 is performed. The torque becomes an upper limit value Tmlu and a lower limit value Tmll of the power limit torque, respectively. Here, the upper limit value Tmlu and the lower limit value Tmll of the power limit torque are examples of torque corresponding to the power limit value. FIG. 10 is a conceptual diagram showing an example of the relationship between the damping torque actually applied to the motor and the crank angle by the engine start control device according to the comparative example.

  Next, FIG. 11 shows the result of frequency analysis performed on the damping torque added to the motor 13 when the damping torque added to the motor 13 is, for example, the upper limit value Tmlu of the motor limit torque. The description will be given with reference. FIG. 11 is a conceptual diagram showing an example of the frequency analysis result of the damping torque according to the comparative example having the same purpose as FIG.

  As shown in FIG. 11, the absolute value of the damping torque applied to the motor 13 is significantly smaller than the theoretical value. Further, it can be seen that torque is generated at an unintended frequency (the right waveform in FIG. 11). That is, in the engine start control device according to the comparative example, the motor 13 causes a torque fluctuation of an unintended frequency.

(Modification)
Next, a modification of the engine start control device according to this embodiment will be described.

  In the engine start control device according to the modification, the relationship between the motor limit gain and the engine speed shown in FIG. 6 is stored in advance in the ECU 30 as a motor limit gain map. Therefore, in the engine start control device according to the modified example, the ECU 30 rotates to the engine pulsation torque specified by, for example, the engine pulsation base torque map shown in FIG. 2 based on the crank angle detected by the crank angle sensor 21. Based on the engine speed detected by the number sensor 22, the damping torque is calculated by multiplying the motor limit gain specified from the motor limit gain map.

  For this reason, in the engine start control device according to the modified example, the load on the ECU 30 can be reduced, which is very advantageous in practice.

<Second Embodiment>
A second embodiment of the engine start control device of the present invention will be described with reference to FIGS. In the second embodiment, the vehicle is provided with a power generation motor, a drive motor, and a power split mechanism, and is the same as the configuration of the first embodiment except that the engine start control process is different corresponding to the configuration. Therefore, in the second embodiment, the description overlapping with that of the first embodiment is omitted, and common portions in the drawings are denoted by the same reference numerals, and FIGS. The description will be given with reference.

  First, a vehicle on which the engine start control device according to the present embodiment is mounted will be described with reference to FIG. FIG. 12 is a block diagram showing the configuration of the vehicle according to the present embodiment having the same purpose as in FIG.

  In FIG. 12, the vehicle 1 includes a power split motor 20 having a power generation motor 18, a drive motor 19, and a planetary gear mechanism. Here, the “power generation motor 18” according to the present embodiment is another example of the “first motor” according to the present invention, and the “drive motor 19” and the “power split mechanism 20” according to the present embodiment are Each is an example of a “second motor” and a “power splitting unit” according to the present invention.

  The engine 11 is connected to the rotating shaft 201 of the planetary carrier of the power split mechanism 20 via the torsional damper 12, and the generator motor 18 is connected to the rotating shaft 202 of the sun gear of the power split mechanism 20. The drive motor 19 is connected to the rotating shaft 203 of the outer ring gear of the power split mechanism 20.

  Here, the motor rotation speed of the generator motor 18 in the vehicle 2 is uniquely determined by the relationship in the alignment chart as shown in FIG. Therefore, the ECU 30 as a part of the engine start control device according to the present embodiment is detected by the rotational speed of the drive shaft 17 determined based on the speed of the vehicle 2 detected by the speed sensor 23 and the rotational speed sensor 22. The motor speed of the generator motor 18 is detected based on the engine speed and the planetary gear ratio ρ of the power split mechanism 20.

  More specifically, the ECU 30 uses the following formula: (motor rotational speed of the generator motor 18) = (1 + ρ) / ρ × (engine rotational speed) − (1 / ρ) × (rotational speed of the drive shaft 17). The motor rotation speed of the generator motor 18 is detected.

  FIG. 13 is an alignment chart of the engine, the generator motor, and the drive shaft according to the present embodiment.

  In the present embodiment, as described above, since the motor rotation speed of the generator motor 18 depends on the rotation speed of the drive shaft 17 (that is, the speed of the vehicle 2), the motor power limit torque obtained by the ECU 30 is as shown in FIG. As described above, the speed differs for each vehicle 2. Here, FIG. 14 is a conceptual diagram showing an example of the relationship between the motor power limit torque and the engine speed according to the present embodiment having the same concept as in FIG.

  In this embodiment, when the motor power limit torque is larger than the motor torque limit value Tml determined by the performance of the generator motor 18, the motor power limit torque is set to the motor torque limit value Tml.

  Therefore, the power limit gain calculated by the ECU 30 is also different for each speed of the vehicle 2 as shown in FIG. Here, FIG. 15 is a conceptual diagram showing an example of the relationship between the power limit gain and the engine speed according to the present embodiment, which has the same concept as in FIG. Note that the dotted line in FIG. 15 indicates the basic damping gain specified by the basic damping gain map shown in FIG. 3, for example.

  After calculating the power limit gain, the ECU 30 calculates the basic vibration suppression gain and the calculated power limit gain based on the engine speed detected by the speed sensor 22 and the speed of the vehicle 2 detected by the vehicle speed sensor 23. Select the smaller of the gains. The relationship between the smaller one of the basic damping gain and the power limit gain selected by the ECU 30 and the engine speed is as shown in FIG. FIG. 16 is a conceptual diagram showing an example of the relationship between the motor limit gain and the engine speed according to the present embodiment having the same concept as in FIG.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed within a scope not departing from the gist or concept of the invention that can be read from the claims and the entire specification. The start control device and method are also included in the technical scope of the present invention.

1 is a block diagram illustrating a configuration of a vehicle according to a first embodiment. It is a conceptual diagram which shows an example of the engine pulsation base torque map which shows the relationship between the engine pulsation base torque and crank angle which concern on 1st Embodiment. It is a conceptual diagram which shows an example of the basic damping gain map which shows the relationship between the basic damping gain and engine speed which concern on 1st Embodiment. It is a conceptual diagram which shows an example of the relationship between the motor power limiting torque and engine speed which concern on 1st Embodiment. It is a conceptual diagram which shows an example of the relationship between the power limiting gain and engine speed which concern on 1st Embodiment. It is a conceptual diagram which shows an example of the relationship between the motor limiting gain and engine speed which concern on 1st Embodiment. It is a conceptual diagram which shows an example of the relationship between the damping torque and crank angle which concern on 1st Embodiment. It is a conceptual diagram which shows an example of the frequency analysis result of the damping torque which concerns on 1st Embodiment. It is a conceptual diagram which shows an example of the relationship between the damping torque and crank angle which concern on the comparative example of 1st Embodiment. It is a conceptual diagram which shows an example of the relationship between the damping torque and the crank angle which the engine starting control apparatus which concerns on the comparative example of 1st Embodiment actually adds to a motor. It is a conceptual diagram which shows an example of the frequency analysis result of the damping torque which concerns on the comparative example of 1st Embodiment. It is a block diagram which shows the structure of the vehicle which concerns on 2nd Embodiment. It is an alignment chart of the engine which concerns on 2nd Embodiment, a generator motor, and a drive shaft. It is a conceptual diagram which shows an example of the relationship between the motor power limiting torque and engine speed which concern on 2nd Embodiment. It is a conceptual diagram which shows an example of the relationship between the power limiting gain and engine speed which concern on 2nd Embodiment. It is a conceptual diagram which shows an example of the relationship between the motor limiting gain and engine speed which concern on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Vehicle, 11 ... Engine, 12 ... Torsional damper, 13 ... Motor, 14 ... Power storage device, 15 ... Transmission, 16 ... Differential gear, 17 ... Drive shaft, 18 ... Electric power generation motor, 19 ... Drive motor, 20 ... Power split mechanism, 21 ... Crank angle sensor, 22 ... Rotation speed sensor, 23 ... Vehicle speed sensor, 30 ... ECU, 40 ... Wheel

Claims (4)

Mounted on a vehicle including an engine and a first motor connected to each other via a damper, and a storage battery capable of supplying electric power to the first motor;
Crank angle detecting means for detecting the crank angle of the engine;
An engine speed that is the engine speed, and a motor speed detector that detects a motor speed that is the speed of the first motor;
Storage means for storing an engine pulsation base torque map capable of specifying a pulsation torque resulting from the rotation of the engine, and a basic damping gain map determined according to resonance generated in a power transmission system including the damper;
When starting the engine, the power limit value of the first motor determined according to the performance of the storage battery, the basic gain determined by the transfer function between the engine and the first motor, and the detected First calculating means for calculating a power limit gain of the first motor based on the stored motor rotation speed and the stored engine pulsation base torque map;
Selecting means for selecting a smaller one of the basic damping gain specified by the stored basic damping gain map and the calculated power limit gain based on the detected engine speed;
Second calculating means for calculating a damping torque by multiplying the selected gain by the engine pulsation torque specified based on the detected crank angle and the stored engine pulsation base torque map;
Setting means for setting the torque of the first motor based on the calculated damping torque;
An engine start control device comprising: control means for drivingly controlling the first motor so as to output the set torque. The vehicle further includes power dividing means having a planetary gear mechanism, a second motor connected to a rotation shaft of an outer ring gear of the power dividing means, and speed detecting means for detecting the speed of the vehicle,
The engine is connected to the rotating shaft of the planetary carrier of the power split means via the damper,
The first motor is connected to a rotating shaft of a sun gear of the power distribution means;
The rotational speed detection means is configured to rotate the motor based on the detected speed, the detected engine rotational speed, and a planetary gear ratio that is a ratio between the number of teeth of the sun gear and the number of teeth of the outer ring gear. The engine start control device according to claim 1, wherein the number is detected.   The first calculating means divides the power limit value by a value obtained by multiplying the detected motor rotational speed by the maximum value of the engine pulsation base torque in the stored engine pulsation base torque map and the basic gain. The engine start control device according to claim 1, wherein the power limit gain is calculated by the calculation. Crank angle detection means for detecting a crank angle of the engine mounted on a vehicle including an engine and a first motor connected to each other via a damper, and a storage battery capable of supplying electric power to the first motor, and the engine An engine pulsation base torque map capable of specifying a pulsation torque resulting from the rotation of the engine, and an engine speed detection means for detecting an engine speed that is the rotation speed of the motor and a motor rotation speed that is the rotation speed of the first motor. And an engine start control method in an engine start control device comprising: a storage means for storing a basic damping gain map determined according to resonance generated in a power transmission system including the damper,
When starting the engine, the power limit value of the first motor determined according to the performance of the storage battery, the basic gain determined by the transfer function between the engine and the first motor, and the detected A first calculation step of calculating a power limit gain of the first motor based on the stored motor rotation speed and the stored engine pulsation base torque map;
A selection step of selecting a smaller one of the basic damping gain specified by the stored basic damping gain map and the calculated power limit gain based on the detected engine speed;
A second calculating step of calculating a damping torque by multiplying the selected gain by the engine pulsation torque specified based on the detected crank angle and the stored engine pulsation base torque map;
A setting step of setting the torque of the first motor based on the calculated damping torque;
And a control step of driving and controlling the first motor so as to output the set torque.

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