JP2007245779A - Method for controlling amount of assist torque - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accelerate a hybrid vehicle more smoothly when it is driven at low speeds, the hybrid vehicle performing torque assist during which the output of an engine is assisted by a motor. <P>SOLUTION: The amount Tmg of torque supplied from the motor 2 to the engine 1 is determined using the product of the amount g (dθ/dt) of motor torque based on the time rate dθ/dt of change of accelerator opening θ and a vehicle speed coefficient h(v) determined based on vehicle speed v. Also, the vehicle speed coefficient h(v) in a low vehicle speed range in which the vehicle speed v is below a first predetermined vehicle speed v1 is made smaller than the vehicle speed coefficient h(v) in other vehicle speed ranges. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an assist torque amount control method used in a hybrid vehicle that performs torque assist for assisting engine output by a motor.

  In recent years, various hybrid vehicles have been conceived in which not only the engine but also the power from the motor is used in combination to improve fuel efficiency. An example of such a hybrid vehicle is one that performs torque assist that assists engine output by a motor.

The amount of torque supplied to the engine from the motor of such a hybrid vehicle is calculated as the engine output torque based on the vehicle speed and the accelerator opening, and the time change rate of the accelerator opening and the elapsed time from the start of the acceleration operation. The target acceleration is determined on the basis of this, and is determined by subtracting the calculated engine output torque from the total torque required to obtain the determined target acceleration. (For example, see Patent Document 1.)
JP 2004-166386 A

  Thus, when controlling the amount of torque supplied from the motor to the engine by the method described in Patent Document 1, if the accelerator pedal is depressed quickly during low-speed traveling, the target acceleration becomes a large value, and thus the target acceleration. The total torque required to obtain the torque increases, and therefore the amount of torque supplied from the motor to the engine also increases. For this reason, even if there is no intention of sudden acceleration, a large torque is supplied from the motor, which may give the driver and other occupants a sense of incongruity. In particular, when the vehicle speed is lower than the vehicle speed during steady driving, specifically when entering a garage, when climbing a slope in a multilevel parking garage, or when driving at a low vehicle speed that is less than the driving speed when following a congested road, When the accelerator is depressed, even if the opening speed is the same, the output change is not constant, and when the assist torque amount is determined with reference to the accelerator opening speed at such a low vehicle speed, the behavior of the vehicle is jerky. A malfunction that can be felt may occur.

  The present invention is configured to solve such problems and to accelerate the vehicle more smoothly during low-speed traveling.

  That is, one of the assist torque amount control methods according to the present invention is used in a hybrid vehicle that performs torque assist that assists engine output by a motor, and is based on the motor torque amount and the vehicle speed based on the time change rate of the accelerator opening. An assist torque amount control method for determining the amount of torque to be supplied from the motor to the engine, wherein the amount of torque supplied from the motor to the engine is smaller than in other vehicle speed regions in a vehicle speed region where the vehicle speed is below a predetermined vehicle speed. It is characterized by.

  It is also used in hybrid vehicles that perform torque assist to assist engine output by the motor, and the amount of torque supplied from the motor to the engine is determined based on the amount of motor torque based on the time change rate of the accelerator opening and the accelerator opening. In the accelerator opening range where the accelerator opening is lower than the predetermined accelerator opening, the amount of torque supplied from the motor to the engine is smaller than other accelerator opening ranges. It is characterized by.

  If this is the case, the amount of torque supplied from the motor to the engine is reduced during low-speed operation, so when the accelerator pedal is depressed quickly during low-speed operation, large assistance is provided regardless of whether or not the vehicle intends to accelerate rapidly. It is possible to prevent the torque from being generated, and therefore, it is possible to prevent the occurrence of a problem that makes the driver and other passengers feel uncomfortable. In addition, if the influence of the time change rate of the accelerator opening on the amount of torque supplied from the motor to the engine during low-speed driving is reduced to reduce the torque amount as a whole, the vehicle speed is particularly lower than that during steady-state driving. At low vehicle speeds, specifically when entering the garage, when climbing slopes in multilevel parking lots, or at low vehicle speeds below the traveling speed when following a congested road, the same opening speed is applied when the accelerator is depressed. Even if it exists, it is possible to prevent the occurrence of a problem that makes the vehicle feel jerky due to the fact that the output change is not constant.

  According to the assist torque control method according to the present invention, the amount of torque supplied from the motor to the engine is reduced during low-speed operation, so whether or not there is a willingness to accelerate suddenly when the accelerator pedal is depressed quickly during low-speed operation. Regardless of the large torque supplied from the motor can be prevented. Therefore, the vehicle can be accelerated more smoothly when traveling at a low speed, and therefore, it is possible to prevent the occurrence of a problem that makes the driver and other passengers feel uncomfortable. In addition, if the influence of the time change rate of the accelerator opening on the amount of torque supplied from the motor to the engine during low-speed driving is reduced to reduce the torque amount as a whole, the vehicle speed is particularly lower than that during steady-state driving. At low vehicle speeds, specifically when entering the garage, when climbing slopes in multilevel parking lots, or when driving at low speeds that are less than the traveling speed when following a congested road, the same opening speed is applied when the accelerator is depressed. Even if it exists, it is possible to prevent the occurrence of a problem that makes the vehicle feel jerky due to the fact that the output change is not constant.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The assist torque amount control method according to the present embodiment includes a drive unit KU that is a drive unit having an engine 1 for traveling driving and a motor 2 for traveling driving as shown in FIG. 1, and a control device that controls the driving unit KU. 7 is a method for controlling the engine 1 of the hybrid vehicle.

  The drive unit KU is formed by directly connecting the engine 1 and the motor 2 so as to rotate integrally. That is, the rotor 2a of the motor 2 is connected to the output shaft 1a of the engine 1 so as to rotate integrally around the same axis. The left and right wheels 3 are driven by these powers to run.

  The motor 2 has a function of starting the engine 1 by applying a driving force to the output shaft 1a when the operation of the engine 1 is stopped. Further, after the engine 1 is started, the operation state of the motor 2 is changed to a power running state in which a driving force is applied to the output shaft 1a in the same direction as the rotation direction of the output shaft 1a to perform torque assist, and from the output shaft 1a It is configured to be switchable to a regenerative state in which driving force is applied to generate power. That is, when the engine 1 is operating, the motor 2 in the power running state is in the same direction as the rotational direction of the output shaft 1a with respect to the output shaft 1a of the engine 1 in order to reduce the fuel consumption of the engine 1. Torque is output to the drive unit and the desired output is supplied as the entire drive unit KU. When the accelerator pedal 8 is not depressed and the charge amount of the battery 4 is small, the motor 2 is set in a regenerative state, and the motor 2 receives driving force from the output shaft 1a to generate power, The battery 4 is charged with the obtained electric power.

  The power supplied from the drive unit KU is transmitted to the automatic transmission 5. Then, after the rotation of the output shaft 1 a is shifted by the automatic transmission 5, the power is transmitted to the left and right wheels 3 via the differential mechanism 6. The automatic transmission 5 has the same configuration as a known automatic transmission with a torque converter used in a conventional automobile. Also, the differential mechanism 6 has the same configuration as that known as that used in conventional automobiles.

  On the other hand, as schematically shown in FIG. 2, the control device 7 mainly includes a microcomputer system including a central processing unit 12, a storage device 13, an input interface 14, and an output interface 15. It is configured. The input interface 14 includes an accelerator opening signal a output from an accelerator state sensor 16 for detecting the opening θ of the accelerator pedal 8, and a brake hydraulic pressure that presses the brake disc 11 with a brake operating force from the brake pedal 9. The hydraulic pressure signal b output from the hydraulic pressure sensor 17 for detecting the brake hydraulic pressure p connected to the master cylinder 10 to be converted into the vehicle, the vehicle speed signal c output from the vehicle speed sensor 18 for detecting the vehicle speed v, the battery At least a charge amount signal d indicating the charge amount E of the battery output from 4 is input. On the other hand, from the output interface, the fuel injection signal e for the fuel injection valve 19 of the engine 1, the ignition pulse f for the spark plug 20 of the engine 1, and the motor 2 to the engine 1 for the motor 2. At least an output control signal g indicating an assist torque amount Tmg that is a supplied torque amount is output.

  Further, the control device 7 assists based on the vehicle speed v indicated by the vehicle speed signal c, the accelerator opening θ indicated by the accelerator opening signal a, and the opening speed dθ / dt which is the time change rate of the accelerator opening θ. An assist torque amount control program for calculating the torque amount Tmg is incorporated at least. This assist torque amount control program is activated every time an ignition switch (not shown) is turned on, and at a predetermined time, for example, at an interval of 0.1 second from the time when the ignition switch (not shown) is turned on. I am trying to start with.

  The assist torque amount Tmg includes an accelerator opening amount f (θ) that is a motor torque amount based on the accelerator opening θ, an opening speed term g (dθ / dt) that is a motor torque amount based on the opening speed dθ / dt, and the vehicle speed. Based on the vehicle speed coefficient h (v), which is a function of v, it is calculated by the following equation (1).

Tmg = f (θ) + g (dθ / dt) h (v) (1)
Specifically, the control device 7 stores an accelerator opening term map in which an accelerator opening term f (θ) corresponding to a typical accelerator opening θ is stored, and an opening corresponding to a typical opening speed dθ / dt. An open speed term map storing a speed term g (dθ / dt) and a vehicle speed coefficient map storing a vehicle speed coefficient h (v) corresponding to a representative vehicle speed v are stored, and the accelerator opening signal a , The opening degree dθ / dt calculated from the change over time of the accelerator opening θ indicated by the accelerator opening signal a, and the vehicle speed v indicated by the vehicle speed signal c. ), An opening speed term g (dθ / dt), and a vehicle speed coefficient h (v). Here, an accelerator opening term map, a vehicle speed coefficient map, and a vehicle speed coefficient map in the present embodiment are shown in FIGS. 3A, 3B, and 3C, respectively.

  The accelerator opening term f (θ) and the opening speed term g (dθ / dt) are the actual output of the engine 1 at each accelerator opening θ and the drive unit KU required at each accelerator opening θ. And an additional output amount of the drive unit KU required at each opening speed dθ / dt is obtained based on experiments. In the present embodiment, the accelerator opening term f (θ) is set to a constant value, that is, 0 at an accelerator opening θ equal to or less than the predetermined accelerator opening θm, and the predetermined accelerator opening θm is set to When the accelerator opening degree θ is higher, the accelerator opening degree term f (θ) increases linearly as the accelerator opening degree θ increases in order to determine that a torque corresponding to start acceleration is required and perform assist. I have to. The predetermined accelerator opening θm is set to about 14 to 15% in a vehicle having an accelerator opening of 10% during steady running at 40 km / h, for example. Further, the opening speed term g (dθ / dt) is also set to a constant value, that is, 0 at an opening speed dθ / dt equal to or lower than a predetermined opening speed (dθ / dt) m, and the predetermined accelerator opening ( At an opening speed dθ / dt exceeding dθ / dt) m, the opening speed term g (dθ / dt) is also increased as the opening speed dθ / dt increases to determine that a large torque is required and to assist. It is designed to increase linearly. In this embodiment, the accelerator opening term f (θ) and the opening speed term g (dθ / dt) increase linearly as the accelerator opening θ or the opening speed dθ / dt increases. However, it may be increased stepwise, and the torque increase rate may be increased as the accelerator opening θ or the opening speed dθ / dt increases.

  Accordingly, if the accelerator is depressed rapidly during low-speed driving, the opening speed term g (dθ / dt) increases corresponding to the increase of the accelerator depressing speed dθ / dt. In order to prevent sudden acceleration even though there is no intention to accelerate, the vehicle speed v is set at the boundary between the steady running and the other running as shown in FIG. In the low vehicle speed region, which is a vehicle speed region below the first predetermined vehicle speed v1, the vehicle speed coefficient h (v) is made smaller than the vehicle speed coefficient h (v) in other vehicle speed regions. Specifically, in a vehicle speed region (hereinafter referred to as a high vehicle speed region) that is equal to or higher than a first predetermined vehicle speed v1 set in the vicinity of the vehicle speed when entering a garage, climbing a slope of a multilevel parking lot, or traveling along a congested road. In some cases, the vehicle speed coefficient h (v) is always set to 1, and when the vehicle speed v is in the low vehicle speed region, the vehicle speed coefficient h (v) is set to a value smaller than 1. That is, the first predetermined vehicle speed v1 corresponds to the predetermined vehicle speed in the claims.

  Furthermore, in the present embodiment, when the vehicle speed v is in the first low vehicle speed region, which is a region lower than the minimum speed at which the vehicle moves, that is, the creep travel speed or the second predetermined vehicle speed v2 set in the vicinity of the walking speed, The vehicle speed coefficient h (v) is always 0. When the vehicle speed v is in the second low vehicle speed region that is equal to or higher than the second predetermined vehicle speed v2 and lower than the first predetermined vehicle speed v1, the vehicle speed coefficient h (v) is a linear function of the vehicle speed v. The corresponding value. Specifically, the vehicle speed coefficient h (v) is set based on the following equation (2).

h (v) = (v−v2) / (v1−v2) (v is vehicle speed (km / h)) (2)
That is, the vehicle speed coefficient h (v) takes a value of 0 or more and less than 1 in the second low vehicle speed region.

  The vehicle speed coefficient map stores a vehicle speed coefficient h (v) calculated based on the expression (2) for a typical vehicle speed v in the second low vehicle speed region. In the present embodiment, the first predetermined vehicle speed v1 is set to 12 km / h, and the second predetermined vehicle speed v2 is set to 5 km / h. However, the first predetermined vehicle speed v1 and the second predetermined vehicle speed v2 are set to 5 km / h. The vehicle speed v2 is not limited to this example, and may be set arbitrarily.

  Here, the control procedure by the assist torque amount control program will be described with reference to FIG. 4 which is a flowchart.

  First, in step S1, the vehicle speed v and the accelerator opening θ are detected through the vehicle speed signal c and the accelerator opening signal a. Then, the process proceeds to step S2.

  Next, in step S2, the accelerator opening change per unit time is determined based on the accelerator opening θ detected in step S1, the previous accelerator opening θ0, and the elapsed time t from when the previous accelerator opening θ0 was detected. It calculates as opening speed d (theta) / dt, and progresses to step S3.

  In step S3, the accelerator opening degree term f (θ) using the accelerator opening degree θ detected in step S1 as a parameter, and the opening speed term g (dθ / dt) using the opening speed dθ / dt calculated in step S2 as parameters. Each is calculated and it progresses to step S4.

  In step S4, it is determined whether the vehicle speed v detected in step S1 is in the high vehicle speed region, the first low vehicle speed region, or the second low vehicle speed region. When the vehicle speed v is in the high vehicle speed region, the process proceeds to step S5. When the vehicle speed v is in the first low vehicle speed region, the process proceeds to step S6. When the vehicle speed v is in the second low vehicle speed region, the process proceeds to step S7.

  In step S5, the vehicle speed coefficient h (v) is set to 1, and the process proceeds to step S8.

  In step S6, the vehicle speed coefficient h (v) is set to 0, and the process proceeds to step S8.

  In step S7, the vehicle speed coefficient h (v) is determined based on the equation (2) using the vehicle speed v as a parameter, and the process proceeds to step S8. Specifically, the vehicle speed coefficient h (v) is determined by interpolation calculation with reference to the vehicle speed coefficient map.

  In step S8, based on the accelerator opening term f (θ), the opening speed term g (dθ / dt), and the vehicle speed coefficient h (v), the assist torque amount Tmg is calculated using the equation (1). The output control signal g is output to the motor 2 so that the motor 2 outputs a torque corresponding to the assist torque amount Tmg, and the process proceeds to step S9.

  In step S9, the accelerator opening degree θ detected in step S1 is stored in the control device 7 as the previous accelerator opening degree θ0.

  Here, the control action by the assist torque control program is shown in FIG. 3, the elapsed time is plotted on the horizontal axis, the opening speed dθ / dt, the opening speed term g (dθ / dt), and the vehicle speed coefficient h (v ) Will be described with reference to FIG.

  First, when the vehicle speed v is in the high vehicle speed range, that is, when the vehicle speed is 12 km / h or more, the control of the steps S1, S2, S3, S4, S5, S8, and S9 is sequentially performed. As described above, the vehicle speed coefficient h (v) is set to 1. Accordingly, when the opening speed dθ / dt is changed as shown in FIG. 5, the opening speed term g (dθ / dt) increases as the opening speed dθ / dt of the accelerator pedal 8 increases in this vehicle speed region. And the vehicle speed coefficient h (v) also increase correspondingly and show a change with time as shown by the solid line in FIG. Then, the assist torque amount Tmg also increases correspondingly.

  On the other hand, when the vehicle speed v is in the first low vehicle speed range, i.e., below 5 km / h, the control of the steps S1, S2, S3, S4, S6, S8, and S9 is sequentially performed. The vehicle speed coefficient h (v) is set to 0 as described above. Therefore, even if the opening speed dθ / dt is changed as shown in FIG. 5, the opening speed term g (dθ / dt) in this vehicle speed range regardless of the opening speed dθ / dt of the accelerator pedal 8. And the vehicle speed coefficient h (v) remain 0 as shown by the one-dot chain line in FIG. That is, in this speed region, no matter how large the opening speed dθ / dt of the accelerator pedal 8 is, it is not reflected in the assist torque amount Tmg, and the assist torque amount Tmg is calculated from the equation (1). Only the term f (θ) is reflected. Further, since the accelerator opening θ is also small in this vehicle speed region, the accelerator opening term f (θ) is also small as shown in FIG. 3A, and in particular, the accelerator opening less than the predetermined accelerator opening θm. At θ, the accelerator opening term f (θ) is a constant value, that is, 0. Therefore, even if the accelerator pedal 8 is operated rapidly, the assist torque amount Tmg is much higher than when the vehicle speed v is in the high vehicle speed range. Can be small.

  Further, when the vehicle speed v is the second low vehicle speed region, that is, the region of 5 km / h or more and less than 12 km / h, the control of the steps S1, S2, S3, S4, S7, S8, and S9 is sequentially performed. In step S7, as described above, the vehicle speed coefficient h (v) is determined based on the equation (2) using the vehicle speed v as a parameter. Therefore, the vehicle speed coefficient h (v) is a value greater than or equal to 0 and less than 1. It is. Therefore, when the opening speed dθ / dt is changed as shown in FIG. 5, the opening speed term g (dθ / dt) and the vehicle speed coefficient h (v) are changed as shown by the broken line in FIG. Is smaller than that when the vehicle speed v is in the high vehicle speed region. That is, the time-dependent change of the assist torque amount Tmg is also smaller than when the vehicle speed v is in the high vehicle speed region, and is as large as when the vehicle speed v is in the high vehicle speed region even if the accelerator pedal 8 is operated rapidly. Assist torque is not generated.

  If the assist torque amount control method according to the present embodiment is adopted, as described above, the vehicle speed v is lower than the vehicle speed at the time of steady running, specifically, when entering the garage, the slope climbing of the multilevel parking lot Or the vehicle speed coefficient h (v) is smaller than 1 which is a value in the high vehicle speed region. Further, since the assist torque amount Tmg is determined by the equation (1) using the product of the open speed term g (dθ / dt) and the vehicle speed coefficient h (v), the vehicle speed v is in the low vehicle speed region. In this case, the influence of the opening speed dθ / dt on the assist torque amount Tmg can be reduced. That is, when the accelerator pedal 8 is depressed quickly when the vehicle speed v is in the low vehicle speed region, it is possible to prevent a large assist torque Tmg from being generated regardless of whether or not there is an intention to accelerate rapidly. Further, when the vehicle speed v is in the low vehicle speed region, the vehicle speed coefficient h (v) is set to be smaller than 1 which is a value in the high vehicle speed region, so that when the accelerator is depressed, the same opening speed dθ / dt is obtained. However, it is possible to prevent a problem that the vehicle behavior is felt jerky due to the fact that the output change is not constant. Therefore, the vehicle can be accelerated more smoothly when the vehicle speed v is in the low vehicle speed region.

  The present invention is not limited to the embodiment described above.

  For example, in the above-described embodiment, a mode in which the vehicle speed coefficient h (v) is determined as described below can be considered.

  Specifically, the vehicle speed coefficient h (v) in the vehicle speed region where the vehicle speed v is equal to or higher than the predetermined vehicle speed v3 is always 1, and the vehicle speed coefficient h (v) in the vehicle speed region where the vehicle speed v is lower than the predetermined vehicle speed v3 is always 0. The vehicle speed coefficient h (v) in the vehicle speed region where the vehicle speed v is equal to or higher than the predetermined vehicle speed v4 is always 1, and the vehicle speed coefficient h (v) in the vehicle speed region where the vehicle speed v is lower than the predetermined vehicle speed v4 is expressed by the following equation (3). A mode of determining using can be considered.

h (v) = v / v4 (3)
In addition, although the above-described embodiment assumes a mode in which a small motor 2 of about 10 kW is combined with a mini vehicle, when a larger motor of 30 kW or more is used, the first low vehicle speed region and the second In any of the low vehicle speed regions, the vehicle speed coefficient h (v) is made to correspond to the vehicle speed v in a linear function, and the rate of change of the vehicle speed coefficient h (v) with respect to the speed is larger in the second low vehicle speed region than in the first low vehicle speed region. You may employ | adopt the aspect to do. Further, the vehicle speed coefficient h (v) does not necessarily correspond to the vehicle speed v in a linear function as long as the value is set to decrease as the vehicle speed decreases. For example, the vehicle speed coefficient h (v) corresponds to the vehicle speed v in a quadratic function. You may make it make it.

  Furthermore, in the above-described embodiment, the assist torque Tmg is determined by using the product of the opening speed term g (dθ / dt) and the vehicle speed coefficient h (v), but the opening speed term g ( dθ / dt) and the accelerator opening coefficient h (θ) which is a function of the accelerator opening, and the accelerator opening coefficient h (θ) is used as the accelerator opening θ, for example, in steady running. Accelerator below the first predetermined accelerator opening θ1 set in the vicinity of the boundary between the time and other states, specifically when entering the garage, when climbing the slope of a multilevel parking garage, or in the vicinity of the accelerator opening when traveling on a congested road It is also possible to consider a mode in which the accelerator opening coefficient is smaller than the accelerator opening coefficient h (θ) in the other accelerator opening area, that is, in the high accelerator opening area where the accelerator opening θ is equal to or greater than the first predetermined accelerator opening θ1. It is done.

  For example, when the accelerator opening degree θ is in the high accelerator opening range, the accelerator opening coefficient h (θ) is always 1, and the accelerator opening degree θ is set in the vicinity of the accelerator opening degree during running near the walking speed. 2 The accelerator opening coefficient h (θ) in the first low accelerator opening region that is equal to or smaller than the predetermined accelerator opening θ2 is always 0, and the first opening when the accelerator opening θ is equal to or larger than the second predetermined accelerator opening θ2. In the second low accelerator opening range below the predetermined accelerator opening θ1, a mode in which the accelerator opening coefficient h (θ) is calculated by the following equation (4) is also conceivable.

h (θ) = (θ−θ2) / (θ1−θ2) (4)
Then, instead of the vehicle speed coefficient map described above, an accelerator opening coefficient map storing an accelerator opening coefficient h (θ) corresponding to a typical accelerator opening θ is stored in the control device 7, and an assist torque amount control program is stored. Alternatively, the accelerator opening coefficient h (θ) may be calculated instead of the vehicle speed coefficient, and the assist torque amount Tmg may be calculated by the following equation (5).

Tmg = f (θ) + g (dθ / dt) h (θ) (5)
Even with this configuration, since the accelerator opening θ is small during low speed operation and the accelerator opening θ is large during high speed operation, the accelerator opening θ is specifically determined during low speed operation, as in the above-described embodiment. To prevent a large assist torque Tmg from being generated regardless of the intention of sudden acceleration when the accelerator pedal 8 is depressed quickly when the accelerator pedal is in the first low accelerator opening region or the second low accelerator opening region. Can do. Further, in the low accelerator opening region, the accelerator opening coefficient h (θ) is set to a value smaller than 1 which is the value of the high accelerator opening region, and therefore the same opening speed dθ / dt when the accelerator is depressed. However, it is possible to prevent the occurrence of a problem that makes the vehicle feel jerky due to the fact that the output change is not constant. Therefore, even if this aspect is adopted, the vehicle can be accelerated more smoothly during low-speed traveling. The first predetermined accelerator opening θ1 and the second predetermined accelerator opening θ2 are not limited to the example described above, and may be set arbitrarily.

  Further, the mode of connection between the engine and the motor is not limited to that described in the above-described embodiment. For example, a mode in which the output shaft of the engine and the output shaft of the motor are connected by a chain, belt, gear, or the like. It may be adopted.

  Further, a value obtained by dividing the opening speed term g (dθ / dt) by the low speed region assist decrease degree H (v), which is a function that is 1 when the vehicle speed v1 is equal to or higher than the predetermined vehicle speed v1 and increases as the vehicle speed v decreases. The assist torque amount Tmg may be determined based on the above. Further, based on a value obtained by dividing the opening speed term g (dθ / dt) by an accelerator opening coefficient H (θ) which is 1 when the accelerator opening θ1 is equal to or larger than a predetermined accelerator opening θ1 and increases as the accelerator opening θ decreases. The assist torque amount Tmg may be determined. In addition, an assist torque reduction amount Tr (> 0) that is an amount by which the vehicle speed v or accelerator opening θ and the assist torque are reduced in order to reduce the assist torque amount Tmg more greatly as the vehicle speed v or the accelerator opening θ decreases. And the assist torque reduction amount Tr may be subtracted from the assist torque amount Tmg calculated based on the opening speed term g (dθ / dt) at a vehicle speed v or accelerator opening θ that is equal to or less than a predetermined value.

  In addition, various changes may be made without departing from the spirit of the present invention.

1 is a schematic diagram showing a vehicle according to an embodiment of the present invention. Schematic which shows the control apparatus which concerns on the same embodiment. Schematic which shows an example of the accelerator opening degree term map memorize | stored in the control apparatus which concerns on the same embodiment, a vehicle speed coefficient map, and a vehicle speed coefficient map. The flowchart which shows the process which the control apparatus which concerns on the same embodiment performs. Explanatory drawing concerning the same embodiment.

Explanation of symbols

1 ... Engine 7 ... Control device v ... Vehicle speed θ ... Accelerator opening

Claims (2)

Assist torque amount that is used in hybrid vehicles that perform torque assist that assists the output of the engine with a motor, and that determines the amount of torque that is supplied from the motor to the engine based on the amount of motor torque based on the time change rate of the accelerator opening and the vehicle speed A control method,
An assist torque amount control method characterized in that, in a vehicle speed region where the vehicle speed is lower than a predetermined vehicle speed, a torque amount supplied from the motor to the engine is smaller than in other vehicle speed regions. Assists in determining the amount of torque to be supplied from the motor to the engine based on the motor torque amount based on the time change rate of the accelerator opening and the accelerator opening, which is used in a hybrid vehicle that performs torque assist that assists the engine output by the motor. A torque amount control method,
An assist torque amount control method characterized in that, in an accelerator opening range where the accelerator opening is lower than a predetermined accelerator opening, the amount of torque supplied from the motor to the engine is smaller than other accelerator opening ranges.

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