JP7159580B2 - hybrid car - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hybrid vehicle, and more specifically, a planetary gear in which three rotating elements arranged in order in a collinear diagram are connected in this order to the rotating shaft of a first motor, the output shaft of an engine, and the drive shaft connected to the axle. The present invention relates to a hybrid vehicle including a mechanism and a second motor that inputs and outputs power to a drive shaft.

Conventionally, as this type of hybrid vehicle, there has been proposed a vehicle drive system in which an engine output shaft, an output member on the axle side, and a rotating electric machine are respectively driven and connected to different rotating elements of a differential gear device. (See, for example, Patent Document 1). 2. Description of the Related Art A vehicle control device that controls a vehicle drive device, when stopping an engine, performs stop control that controls a rotating electric machine so as to gradually reduce the rotation speed of the engine toward a target stop position, and also controls vehicle acceleration. A correction torque that cancels the inertia torque generated by the moment of inertia of the rotating electric machine is derived in response to and is controlled so that the correcting torque is output from the rotating electric machine after the stop control is completed. As a result, even when the vehicle is accelerating or decelerating, the engine can be stopped at a predetermined target stop position with high accuracy.

JP 2010-167908 A

A differential value of the number of revolutions of a motor that inputs and outputs power to a drive shaft connected to an axle is also commonly used to detect the acceleration of a vehicle. A resolver is often used as a sensor for detecting the rotation speed of a motor, but in this case, the secondary error of the resolver (in the case of a shaft angle multiplier of 2X) may act as a low-frequency component or a DC component on the rotation speed of the motor. There is a factor of acceleration calculation error.

A main object of the hybrid vehicle of the present invention is to calculate a correction torque more appropriately according to the acceleration of the vehicle.

The hybrid vehicle of the present invention employs the following means in order to achieve the above main object.

The hybrid vehicle of the present invention is
engine and
a first motor capable of inputting and outputting power;
a planetary gear mechanism in which three rotating elements arranged in order in a collinear diagram are connected in this order to the rotation shaft of the first motor, the output shaft of the engine, and the drive shaft connected to the axle;
a second motor capable of inputting and outputting power to the drive shaft;
stop torque to be output from the first motor so that when the engine is stopped, the output shaft of the engine stops within a predetermined rotation angle range in order to improve startability of the engine next time; is calculated, and the correction torque to be output from the first motor in order to cancel the inertia torque generated by the moment of inertia of the first motor according to the acceleration of the vehicle is calculated based on the differential value of the rotation speed of the second motor. a control device that calculates and controls the first motor so that the sum of the stopping torque and the correction torque is output from the first motor;
A hybrid vehicle comprising
When the rotation speed of the second motor is equal to or higher than a threshold rotation speed, the control device calculates the correction torque based on the effective torque output to the drive shaft and the moment of inertia of the first motor.
It is characterized by

In the hybrid vehicle of the present invention, basically, when stopping the engine, the output shaft of the engine stops within a predetermined rotation angle range in order to improve the startability of the engine next time. 1 Calculate the stopping torque to be output from the motor. On the other hand, in order to cancel the inertia torque generated by the moment of inertia of the first motor according to the acceleration of the vehicle, the correction torque to be output from the first motor is calculated based on the differential value of the rotation speed of the second motor. When the rotation speed of the motor is equal to or higher than the predetermined rotation speed, the correction torque is calculated based on the effective torque output to the drive shaft and the moment of inertia of the first motor. Then, the first motor is controlled so that the sum of the stop torque and the correction torque is output from the first motor. Here, the threshold rotation speed is the rotation speed range in which the second-order error of the resolver that detects the rotation speed of the second motor becomes a low-frequency component and a DC component with respect to the rotation speed of the second motor, causing an error. is determined in advance as the lower limit of rotation speed or a rotation speed slightly smaller than this. As a result, it is possible to more properly calculate the correction torque according to the acceleration of the vehicle.

In the hybrid vehicle of the present invention, the control device calculates a differential value of the rotation speed of the second motor as the rotation speed increases in a predetermined rotation speed region in which the threshold rotation speed is the lower limit rotation speed. The correction torque may be calculated so as to change from the torque to the correction torque calculated based on the effective torque and the moment of inertia of the first motor. This makes it possible to smoothly switch between the correction torque calculated based on the differential value of the rotational speed of the second motor, the effective torque, and the correction torque calculated based on the moment of inertia of the first motor.

1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the invention; FIG. FIG. 10 is an explanatory diagram using a collinear chart showing the relationship between the rotational speeds of the rotating elements of the planetary gear 30 when deceleration occurs while the engine 22 is stopped; 4 is a flowchart showing an example of a correction torque processing routine executed by HVECU 70; 4 is a flow chart showing an example of a differential correction torque calculation process; 7 is a flowchart showing an example of simple correction torque calculation processing; It is an explanatory view showing an example of a driving force setting map converted into running resistance. It is explanatory drawing which shows an example of the reflection rate setting map for running resistance. FIG. 10 is an explanatory diagram showing an example of an estimated gradient reflection rate setting map; FIG. 11 is a flow chart showing an example of a correction torque processing routine of a modified example; FIG. FIG. 4 is an explanatory diagram showing an example of a differential expression reflection rate setting map;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing the outline of the configuration of a hybrid vehicle 20 as one embodiment of the present invention. As illustrated, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as "HVECU"). 70 and.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 .

Although not shown, the engine ECU 24 is configured as a microprocessor centering on a CPU, and in addition to the CPU, it has a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. . Signals from various sensors necessary for controlling the operation of the engine 22, such as the crank angle θcr from the crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22, are input to the engine ECU 24 from the input port. It is Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through an output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23 .

The planetary gear 30 is configured as a single pinion planetary gear mechanism. The sun gear of the planetary gear 30 is connected to the rotor of the motor MG1. A ring gear of the planetary gear 30 is connected to a drive shaft 36 that is connected to drive wheels 39a and 39b via a differential gear 38. As shown in FIG. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28 .

The motor MG1 is configured as, for example, a synchronous generator-motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator-motor, and has a rotor connected to the drive shaft 36 . Inverters 41 , 42 are connected to motors MG<b>1 , MG<b>2 and are connected to battery 50 via power line 54 . The motors MG1 and MG2 are rotationally driven by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as a “motor ECU”) 40 .

Although not shown, the motor ECU 40 is configured as a microprocessor centering on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. . The motor ECU 40 receives signals from various sensors necessary to drive and control the motors MG1 and MG2, such as rotational position θm1 from rotational position detection sensors 43 and 44 for detecting the rotational positions of the rotors of the motors MG1 and MG2. , .theta.m2, etc. are input through the input port. As the rotational position detection sensors 43 and 44, resolvers are used in the embodiment. The motor ECU 40 outputs switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 through output ports. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions .theta.m1 and .theta.m2 of the rotors of the motors MG1 and MG2 from the rotational position detection sensors 43 and 44, respectively.

The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the inverters 41 and 42 via a power line 54 . The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52 .

Although not shown, the battery ECU 52 is configured as a microprocessor centering on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 through an input port. Signals input to the battery ECU 52 include, for example, the voltage Vb of the battery 50 from the voltage sensor 51a installed between the terminals of the battery 50 and the current of the battery 50 from the current sensor 51b attached to the output terminal of the battery 50. Ib, the temperature Tb of the battery 50 from the temperature sensor 51c attached to the battery 50 can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the power storage ratio SOC based on the integrated value of the current Ib of the battery 50 from the current sensor 51b, and sets the input/output limits Win, Wout of the battery 50 based on the calculated power storage ratio SOC and the battery temperature Tb. is calculated. The power storage ratio SOC is the ratio of the amount of electric power that can be discharged from the battery 50 to the total capacity of the battery 50 . The input/output limits Win, Wout of the battery 50 are the maximum charging/discharging power to which the charging/discharging of the battery 50 is allowed.

Although not shown, the HVECU 70 is configured as a microprocessor centering on a CPU, and in addition to the CPU, has a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Signals from various sensors are input to the HVECU 70 through input ports. Signals input to the HVECU 70 include, for example, an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81 . Further, the accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83, the brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, and the vehicle speed sensor 88. Vehicle speed V and the like can also be mentioned. The HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via communication ports, as described above. The HVECU 70 also calculates an estimated gradient θ as an estimated value of the road gradient. The estimated gradient .theta. can be calculated, for example, from the torque (effective driving force) output to the drive shaft 36 and the vehicle weight M as .theta.=arcsin(Td*/(M.g)). The effective driving force Tcr can be calculated by Equation (2), which will be described later.

The hybrid vehicle 20 of the embodiment thus configured runs in a hybrid running (HV running) mode or an electric running (EV running) mode. Here, the HV travel mode is a mode in which the vehicle travels with the engine 22 being operated, and the EV travel mode is a mode in which the vehicle travels without the engine 22 being operated.

The HVECU 70 first sets a required torque Td* required for running (to be output to the drive shaft 36) based on the accelerator opening Acc from the accelerator off-pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. do. Subsequently, the set required torque Td* is multiplied by the rotational speed Nd of the drive shaft 36 to calculate the required traveling power Pdrv* required for traveling. Here, as the rotation speed Nd of the drive shaft 36, a rotation speed obtained by multiplying the rotation speed Nm2 of the motor MG2 or the vehicle speed V by a conversion factor can be used. Then, the required charging/discharging power Pb* of the battery 50 (positive value when the battery 50 is charged) is added to the calculated required driving power Pdrv* to set the required power Pe* required for the vehicle. Here, charging/discharging required power Pb* is set based on difference ΔSOC between power storage ratio SOC of battery 50 and target ratio SOC* so that the absolute value of difference ΔSOC becomes small. Next, it is determined whether the current driving mode is the HV driving mode or the EV driving mode, and if it is determined to be the EV driving mode, it is determined whether or not the required power Pe* is greater than the starting threshold value Pstart. judge. Here, starting threshold value Pstart is a threshold value for determining whether or not to start engine 22 , and is set to a value lower than output limit Wout of battery 50 . When it is determined that the required power Pe* is equal to or less than the starting threshold value Pstart, it is determined that the EV driving mode is to be continued, the torque command Tm1* for the motor MG1 is set to 0, and the input/output limits Win, Wout of the battery 50 are set. The torque command Tm2* for the motor MG2 is set so that the required torque Td* (required running power Pdrv*) is output to the drive shaft 36 within the range. Then, the torque commands Tm1* and Tm2* are transmitted to the motor ECU 40. Motor ECU 40 performs switching control of transistors of inverters 41 and 42 so that motors MG1 and MG2 are driven by torque commands Tm1* and Tm2*.

On the other hand, when it is determined that the required power Pe* is greater than the starting threshold value Pstart, an engine start process is executed in which the engine 22 is started by cranking the motor MG1 in order to shift from the EV running mode to the HV running mode. When the engine 22 is started and shifts to the HV running mode, the required power Pe* is output from the engine 22, and the required torque Td* is output to the drive shaft 36 within the range of the input/output limits Win, Wout of the battery 50. , the target operating point (target rotation speed Ne*, target torque Te*) of the engine 22 and torque commands Tm1*, Tm2* of the motors MG1, MG2 are set. The target operating point (target rotational speed Ne*, target torque Te*) of the engine 22 is determined by selecting an optimum operation line that optimizes fuel efficiency by taking noise, vibration, etc. into consideration among the operating points (rotational speed, torque) of the engine 22. An operation point (rotational speed, torque) on the optimum operation line corresponding to the required power Pe* is obtained and set in advance. A target operating point (target rotation speed Ne*, target torque Te*) of the engine 22 is transmitted to the engine ECU 24 . The torque commands Tm1* and Tm2* for the motors MG1 and MG2 are transmitted to the motor ECU 40. The engine ECU 24 performs intake air amount control, fuel injection control, ignition control, etc. of the engine 22 so that the engine 22 is operated based on the target operating point. Motor ECU 40 controls inverters 41 and 42 as described above.

When the vehicle is traveling in the HV driving mode, the requested power Pe* is compared with the stop threshold value Pstop, and if it is determined that the requested power Pe* is smaller than the stopping threshold value Pstop, the HV driving mode is switched to the EV driving mode. Then, the operation of the engine 22 is stopped. At this time, in order to improve startability when the engine 22 is started next time, the engine 22 stop processing is executed so that the crank angle when the engine 22 is stopped is within a predetermined crank angle range. Specifically, first, the rotation speed Ne and the crank angle θ of the engine 22 are detected. Subsequently, a torque command Tm1* (stopping torque) for the motor MG1 is calculated so that the rotation speed Ne of the engine 22 becomes the target rotation speed at the time of stopping determined by experiment or the like with respect to the crank angle θ, and the motor MG1 is stopped. The rotational speed Ne of the engine 22 is decreased by controlling with the calculated torque command Tm1*. Then, a torque command Tm1* (stopping torque) for the motor MG1 is calculated so that the crank angle finally stops within a predetermined crank angle range, and the motor MG1 is controlled by the calculated torque command Tm1* to stop the engine 22. do.

Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, in particular, the operation when the operation of the engine 22 is stopped will be described. As described above, the engine stop processing by the motor MG1 is executed. At this time, when the vehicle accelerates or decelerates, inertia torque acts on the crankshaft 26 of the engine 22 due to the acceleration (deceleration). FIG. 2 is a collinear diagram showing the relationship between the rotational speeds of the rotating elements of the planetary gear 30 when deceleration occurs while the engine 22 is stopped. In the figure, ρ indicates the gear ratio of the planetary gear 30 (the number of teeth of the sun gear/the number of teeth of the ring gear). The S axis indicates the rotation speed of the sun gear of the planetary gear 30, which is the rotation speed Nm1 of the motor MG1, the C axis indicates the rotation speed of the carrier of the planetary gear 30, which is the rotation speed Ne of the engine 22, and the R axis is the rotation speed of the motor MG2. The rotational speed Nr of the ring gear of the planetary gear 30, which is Nm2, is shown. The rotation speed Nd of the drive shaft 36 is obtained by multiplying the rotation speed Nm2 of the motor MG2 (the rotation speed Nr of the ring gear) by the gear ratio G. Now, let us consider a case in which the vehicle decelerates from a straight line in a collinear chart and is about to shift to a dashed line. In this case, if this deceleration does not change the rotation speed Nm1 of the motor MG1, a torque (inertia torque) acts on the crankshaft 26 of the engine 22 in a direction to stop the rotation. In the embodiment, a correction torque Tgp is calculated as torque to be output from the motor MG1 in order to cancel this inertia torque, and the engine 22 is stopped by adding this correction torque Tgp to the torque Tm2 of the motor MG1 by the engine stop processing. The crank angle at that time is kept from deviating from a predetermined crank angle range. FIG. 3 is a flow chart showing an example of a correction torque processing routine executed by the HVECU 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, every several milliseconds).

When the correction torque processing routine is executed, the HVECU 70 first executes processing for inputting the rotational speed Nm2 of the motor MG2 (step S100). In the embodiment, the rotational speed Nm2 of the motor MG2 is calculated based on the rotational position θm2 of the rotor of the motor MG2 from the rotational position detection sensor 44, and is inputted from the motor ECU 40 through communication.

Subsequently, the absolute value of the input rotation speed Nm2 of the motor MG2 is compared with the threshold values Nref1 and Nref2 (step S110). Here, the threshold value Nref1 is such that the secondary error of the resolver as the rotational position detection sensor 44 that detects the rotational speed Nm2 of the motor MG2 becomes a low frequency component and a direct current component with respect to the rotational speed Nm2 of the motor MG2. It is predetermined as a lower limit rotation speed or a rotation speed smaller than the lower limit rotation speed in the rotation speed range. The threshold Nref2 is a number of revolutions smaller than the threshold Nref1 and is for providing hysteresis.

When it is determined in step S110 that the absolute value of the rotation speed Nm2 of the motor MG2 is less than the threshold value Nref2, the correction torque Tgp is calculated by a differential equation (step S130). Calculation of the correction torque Tgp by a differential formula is performed by a differential formula correction torque calculation process illustrated in FIG. Calculation of the correction torque Tgp by a differential formula will be described later. On the other hand, when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref1, the correction torque Tgp is calculated using a simple formula (step S150). Calculation of the correction torque Tgp by the simple formula is performed by the simple formula correction torque calculation process illustrated in FIG. Calculation of the correction torque Tgp by a simple formula will also be described later. When the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref2 and less than the threshold value Nref1, it is determined whether or not it is the first round of control (step S120). The correction torque Tgp is calculated (step S130), and when it is determined that it is not the first round of control, the correction torque Tgp is calculated by the previous formula (step S140). The first round of control means the first time when addition of the correction torque Tgp is started. The previous formula means the formula (differential formula or simple formula) used when calculating the correction torque Tgp when this routine was executed last time. Therefore, when it is not the first round of control, the region where the threshold value Nref2 or more and the threshold value Nref1 is less than the threshold value Nref1 is a hysteresis of whether the correction torque Tgp is calculated by the differential formula or the simple formula, and the differential formula is frequently used. This suppresses switching between the calculation of the correction torque Tgp and the calculation of the correction torque Tgp by the simple formula.

After calculating the correction torque Tgp, it is determined whether or not the engine stop process is in progress (step S160). When it is determined that the engine stop process is being performed, the process of adding the correction torque Tgp to the torque (stop torque) to be output from the motor MG1 by the engine stop process is performed (step S170), and the routine ends. When it is determined that the engine stop processing is not being performed, the processing of adding the correction torque Tgp to the torque to be output from the motor MG1 is prohibited (step S170), and this routine ends.

Calculation of the corrected torque Tgp by the differential formula is performed by first multiplying the rotational speed Nm2 of the motor MG2 by the gear ratio G to calculate the rotational speed Nd of the drive shaft 36 ( step S200). Subsequently, the rotational speed Nd calculated the last time this routine was executed (previous Nd) is subtracted from the calculated rotational speed Nd to calculate the drive shaft rotational speed deviation ΔNd (step S210). Here, the drive shaft rotational speed deviation ΔNd becomes a differential value of the rotational speed Nd of the drive shaft 36 when divided by the control period.

Subsequently, a basic correction torque Tgpb is calculated from the drive shaft rotational speed deviation ΔNd (step S220). A torque Tm1 of the motor MG1 is expressed by the following equation (1). The first term on the right side is the torque for balancing the torque Te of the engine 22, the second term on the right side is the inertia torque due to the rate of change of the rotation speed Ne of the engine 22, and the third term on the right side is the torque of the drive shaft 36. It is the inertia torque due to the rate of change of the rotation speed Nd. Ie is the moment of inertia of the engine 22, Ig is the moment of inertia of the motor MG1, ωe is the angular velocity of the crankshaft 26, and ωd is the angular velocity of the drive shaft 36. Since the moment of inertia due to the acceleration (deceleration) of the vehicle is the moment of inertia due to the rate of change in the rotational speed Nd of the drive shaft 36, the third term on the right side of equation (1) can be obtained. The time derivative of the angular velocity ωd can be obtained by dividing the drive shaft rotational speed deviation ΔNd by the control cycle and converting the units. The third term on the right side can be calculated. In the embodiment, the calculated third term on the right side is used as the basic correction torque Tgpb.

Then, the calculated basic correction torque Tgpb is guarded against upper and lower limits to calculate the correction torque Tgp (step S230), and the routine ends. The upper and lower limit guard sets the basic correction torque Tgpb to the correction torque Tgp when the basic correction torque Tgpb is within the range consisting of the maximum torque Tmax and the minimum torque Tmin that are allowable as the correction torque Tgp, and the basic correction torque Tgpb is set to the maximum torque Tmax or more. When the basic correction torque Tgpb is less than the minimum torque Tmin, the minimum torque Tmin is used as the correction torque Tgp.

Calculation of the correction torque Tgp by the simple formula first calculates the effective driving force Tcr of the drive shaft 36 (step S300), as shown in the simple formula correction torque calculation process of FIG. As shown in the following equation (2), the effective driving force Tcr is the engine direct torque output from the engine 22 and output to the drive shaft 36 via the planetary gear 30 and the torque output from the motor MG2 and output to the drive shaft 36. calculated as the sum of the motor running torque The engine direct torque can be converted from the torque Tm1 of the motor MG1.

Subsequently, a running resistance-converted basic driving force Trlb obtained by converting the running resistance to the drive shaft 36 is calculated (step S310). In the embodiment, the basic driving force Trlb converted to running resistance is determined by experiments or the like in advance from the relationship between the vehicle speed V and the basic driving force Trlb converted to running resistance, and is stored as a driving force setting map converted to running resistance. Then, the running resistance converted basic driving force Trlb is obtained. FIG. 6 shows an example of a driving force setting map converted into running resistance. As shown in the figure, the running resistance converted basic driving force Trlb increases as the vehicle speed V increases. Then, a running resistance reflection factor α is calculated based on the rotational speed Nd of the drive shaft 36 (step S320), and the running resistance equivalent basic driving force Trlb is multiplied by the running resistance reflection factor α to obtain the running resistance equivalent driving force Trl. Calculate (step S330). In the embodiment, the relationship between the rotational speed Nd of the drive shaft 36 and the running resistance reflection rate α is determined in advance and stored as a running resistance reflection rate setting map. When the rotational speed Nd is given, the running resistance reflection rate α is derived from the map. An example of the running resistance reflection rate setting map is shown in FIG. As shown in the figure, in the embodiment, the running resistance reflection rate α is 100% when the absolute value of the rotation speed Nd of the drive shaft 36 is large, and 0% when it is small.

Next, an estimated gradient converted basic driving force Tθb as a driving force acting on the drive shaft 36 is calculated based on the estimated gradient θ (step S340). The estimated slope-converted basic driving force Tθb is obtained by predetermining the relationship between the estimated slope θ and the estimated slope-converted basic driving force Tθb and storing it as an estimated slope-converted driving force setting map. The gradient conversion basic driving force Tθb is derived, or the force (Mgsin θ: M is the mass of the vehicle) acting in the longitudinal direction of the vehicle with respect to the estimated gradient θ is calculated and converted to the torque of the drive shaft 36. can be obtained by Then, the muscle low gradient reflection rate β is calculated based on the rotation speed Nd of the drive shaft 36 (step S350), and the estimated gradient converted basic driving force Tθb is multiplied by the estimated gradient reflection rate β to obtain the estimated gradient converted driving force Tθ. is calculated (step S360). In the embodiment, the estimated gradient reflection rate β is determined by predetermining the relationship between the rotation speed Nd of the drive shaft 36 and the estimated gradient reflection rate β and storing it as an estimated gradient reflection rate setting map. Given the rotational speed Nd, the estimated gradient reflection rate β is derived from the map. An example of the estimated gradient reflection rate setting map is shown in FIG. As shown in the figure, in the embodiment, the estimated gradient reflection rate β is 100% when the absolute value of the rotation speed Nd of the drive shaft 36 is large, and 0% when it is small.

Subsequently, the drive shaft effective torque Td is calculated as the sum of the effective driving force Tcr, the running resistance converted driving force Trl, and the estimated gradient converted driving force Tθ (step S370). The basic correction torque Tgpb is converted from the driving shaft execution torque Td (step S380). As described above, the inertia torque of the motor MG1 is the third term on the right side of Equation (1). The time differential of the angular velocity ωd of the drive shaft 36 can be obtained by dividing the torque of the drive shaft 36 by the moment of inertia. It can be obtained by dividing the moment of inertia of 39a and 39b, the total moment of inertia of the vehicle weight (converted to the moment of inertia), and the like. Since the total moment of inertia can be predetermined, using these values the time derivative of the angular velocity .omega.d of the drive shaft 36 can be obtained. As described above, the moment of inertia (Ig) of the motor MG1 can be determined in advance, so the third term on the right side can be calculated. In the embodiment, the calculated third term on the right side is used as the basic correction torque Tgpb.

Then, the calculated basic correction torque Tgpb is subjected to upper/lower limit guarding to calculate the correction torque Tgp (step S390), and the routine ends. The upper/lower limit guard is the same as step S230 of the differential correction torque calculation process of FIG.

In the hybrid vehicle 20 of the embodiment described above, when the absolute value of the rotation speed Nm2 of the motor MG2 is less than the threshold value Nref2, the correction torque Tgp is calculated by a differential expression, and the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref1. When , the correction torque Tgp is calculated by a simple formula. The threshold value Nref1 is the rotational speed at which the secondary error of the resolver as the rotational position detection sensor 44 that detects the rotational speed Nm2 of the motor MG2 causes an error as a low frequency component or a DC component with respect to the rotational speed Nm2 of the motor MG2. Since the rotation speed is the lower limit of the range or a rotation speed smaller than this, when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref1, the correction torque Tgp is calculated by a simple formula, whereby the angular velocity ωd of the drive shaft 36 is calculated. can be calculated more properly. As a result, it is possible to more properly calculate the correction torque according to the acceleration of the vehicle. In addition, when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref2 and less than the threshold value Nref1, the correction torque Tgp is calculated by the previous formula. can be suppressed from being frequently switched.

In the hybrid vehicle 20 of the embodiment, when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref2 and less than the threshold value Nref1, the correction torque Tgp is calculated using the previous formula. However, the correction torque Tgp1 based on the differential formula and the correction torque Tgp2 based on the simple formula may be gradually replaced in a region where the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref2 and less than the threshold value Nref1. In this case, instead of the correction torque processing routine of FIG. 3, the correction torque processing routine of FIG. 9 may be executed.

In the correction torque processing routine of FIG. 9, first, it is determined whether or not the engine stop processing is being performed (step S500). When it is determined that the engine stop processing is not being performed, the correction torque Tgp is set to 0, and this routine ends.

When it is determined that the engine is being stopped, the rotation speed Nm2 of the motor MG2 is input (step S510), and the differential expression reflection rate K1 is set based on the absolute value of the rotation speed Nm2 of the motor MG2 (step S520). In the embodiment, the differential expression reflection rate K1 is determined by predetermining the relationship between the absolute value of the rotation speed Nm2 of the motor MG2 and the differential expression reflection rate K1 and storing it as a differential expression reflection rate setting map. Given the absolute value of Nm2, it was set by deriving the corresponding differential equation reflection rate K1 from the map. An example of the differential expression reflection rate setting map is shown in FIG. In the map of FIG. 10, the differential expression reflection rate K1 is 100% when the absolute value of the rotation speed Nm2 of the motor MG2 is less than the threshold value Nref2, and It gradually decreases as the absolute value of the rotation speed Nm2 increases, and is 0% when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref1.

Subsequently, the differential correction torque Tgp1 is calculated by the differential correction torque calculation process of FIG. 4 (step S530), and the correction torque Tgp2 is calculated by the simple correction torque calculation process of FIG. 5 (step S540). ). Then, as shown in the following equation (3), the corrected torque Tgp1 by the differential formula multiplied by the differential formula reflection rate K1 and the corrected torque Tgp2 by the simple formula multiplied by subtracting the differential formula reflection rate K1 from 100 and multiplied by (step S550), and the routine ends.

Tgp=K1・Tgp1+(100−K1)・Tgp2 (3)

In a hybrid vehicle that executes the correction torque processing routine of such a modified example, it is possible to smoothly switch between the correction torque Tgp1 based on the differential formula and the correction torque Tgp2 based on the simple formula. The differential expression reflection rate K1 is 100% when the absolute value of the rotation speed Nm2 of the motor MG2 is less than the threshold value Nref2, and is 0% when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or higher than the threshold value Nref1. When the absolute value of the number Nm2 is less than the threshold value Nref2, the correction torque Tgp is calculated by a differential formula, and when the absolute value of the rotation speed Nm2 of the motor MG2 is equal to or greater than the threshold value Nref1, the correction torque Tgp is calculated by a simple formula. As a result, the differential value of the angular velocity ωd of the drive shaft 36 can be calculated more appropriately, and the correction torque corresponding to the acceleration of the vehicle can be calculated more appropriately.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the engine 22 corresponds to the "engine", the motor MG1 corresponds to the "first motor", the planetary gear 30 corresponds to the "planetary gear mechanism", the motor MG2 corresponds to the "second motor", HVECU 70, engine ECU 24, and motor ECU 40 correspond to a "control device."

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the manufacturing industry of hybrid vehicles and the like.

20 hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheels, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 46 capacitor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 70 hybrid electronic control unit (HVECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor , MG1, MG2 motors.

Claims (1)

engine and
a first motor capable of inputting and outputting power;
a planetary gear mechanism in which three rotating elements arranged in order in a collinear diagram are connected in this order to the rotation shaft of the first motor, the output shaft of the engine, and the drive shaft connected to the axle;
a second motor capable of inputting and outputting power to the drive shaft;
stop torque to be output from the first motor so that when the engine is stopped, the output shaft of the engine stops within a predetermined rotation angle range in order to improve startability of the engine next time; and differentiate the correction torque to be output from the first motor in order to cancel the inertia torque generated by the moment of inertia of the first motor according to the acceleration of the vehicle based on the differential value of the rotation speed of the second motor. a control device for controlling the first motor so that the sum of the stop torque and the correction torque, which is calculated by a formula correction torque calculation process , is output from the first motor;
A hybrid vehicle comprising
When the number of rotations of the second motor is equal to or higher than the threshold number of rotations, the control device divides the effective torque output to the drive shaft by the moment of inertia of the drive shaft. calculating the correction torque by a simplified correction torque calculation process different from the differential correction torque calculation process by multiplying by the reciprocal of the gear ratio of the planetary gear mechanism ;
A hybrid vehicle characterized by:

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