JP5618007B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to an improvement in traveling control when a vehicle is coasting.

  2. Description of the Related Art Conventionally, in a vehicle having a power interrupting device that interrupts power transmission between an engine and a drive wheel, a vehicular travel control device that interrupts the power transmission by the power interrupting device during inertial traveling has been known. . For example, this is the clutch control device described in Patent Document 1. In Patent Document 1, a clutch provided in a power transmission path functions as the power interrupting device, and the clutch control device is operated when the accelerator pedal is suddenly returned from a state where the accelerator pedal is depressed. In addition, the clutch is released to cut off power transmission between the engine and the drive wheels. By doing so, the fuel consumption rate can be improved.

Japanese Patent Application Laid-Open No. 2002-227885 JP 2003-074682 A JP 2000-074201 JP 2007-187090 A JP 2001-233196 A JP 2007-291919 A

  The driver expects that a so-called engine brake will be applied when the accelerator pedal that has been depressed is suddenly returned, and therefore, a certain degree of deceleration is considered to occur. However, as in the clutch control device of Patent Document 1, if the power transmission between the engine and the drive wheels is interrupted uniformly on the condition that the accelerator pedal is suddenly returned, for example, at a low vehicle speed. When the running resistance of the vehicle is small, for example, a feeling of deceleration that is poorer than the driver's expectation can be obtained, which may cause the driver to feel uncomfortable. Such a problem is not yet known.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicular travel control device that can improve fuel efficiency and reduce a sense of incongruity caused by a driver during inertial driving. It is to provide.

The gist of the first invention for achieving the above object is as follows: (a) In a vehicle provided with a power interrupting device that interrupts power transmission between the engine and the drive wheels, the power interrupting device during inertial running. A vehicle running control device for executing free-run control for shutting off the power transmission and stopping the engine by (b) starting the free-run control based on the vehicle speed before starting the free-run control. And determining an estimated vehicle deceleration when the free-run control is started, and (c) calculating the estimated vehicle deceleration and the target vehicle deceleration at the start of the free-run control. The free-run control is executed when the absolute value of the difference is smaller than a predetermined deceleration difference determination value .

In this way, if the free-run control is executed, the engine does not become a running load. Therefore, compared to the case where the power transmission between the engine and the drive wheels is not cut off during the inertia running, It is possible to improve fuel consumption. Further, when the free run control is executed, it is considered that a vehicle deceleration close to the target vehicle deceleration at the start of the free run control, for example, a vehicle deceleration close to a desired vehicle deceleration can be easily obtained. Therefore, even if the free-run control is executed, it is possible to reduce a sense of incongruity that occurs to the driver that the feeling of deceleration is poor. That is, it is possible to improve fuel efficiency by executing the free run control while suppressing deterioration of drivability during inertial running. More specifically, the desired vehicle deceleration is a vehicle deceleration requested by the driver. The fuel consumption is, for example, the travel distance per unit fuel consumption, and the improvement in fuel consumption is that the travel distance per unit fuel consumption is increased, or the fuel consumption rate (= fuel consumption). / Drive wheel output) is reduced. Conversely, the reduction (deterioration) in fuel consumption means that the travel distance per unit fuel consumption is shortened or the fuel consumption rate is increased. Further, the free run control is executed when the estimated vehicle deceleration is close to the target vehicle deceleration at the start of the free run control. It is possible to easily determine the fuel efficiency, and it is possible to improve fuel efficiency by executing the free-run control while suppressing deterioration of drivability during inertial running.

Further, it is an gist of the second invention, a first shot Ming running control apparatus for a vehicle, and estimates the estimated vehicle deceleration based on the gradient of the traveling path of travel (a) said vehicle (B) The target vehicle deceleration at the start of the free-run control is determined based on the gradient of the travel path. In this way, since the vehicle deceleration during inertial traveling changes according to the gradient of the traveling road, whether the free-run control is executed as compared with the case where the gradient of the traveling road is not taken into account. It is possible to appropriately judge whether or not.

The gist of the third invention is the vehicle travel control apparatus according to the second invention, wherein the target vehicle deceleration at the start of the free-run control is smaller as the descending slope of the travel path is larger. It is characterized by. Here, the greater the descending slope of the travel path, the easier the vehicle is accelerated by the slope, so the driver does not expect a large vehicle deceleration. Therefore, according to the third aspect of the invention, it is possible to determine the target vehicle deceleration at the start of the free-run control in accordance with the deceleration feeling that the driver expects on the downhill traveling road. is there.

The gist of the fourth invention is the vehicular travel control apparatus according to the second invention or the third invention, wherein when the travel path is an up slope, the travel path is an up slope. Compared with the case where there is no, the free-run control is easily performed. Here, on the uphill traveling road, when the free run control is executed during coasting, the vehicle decelerates due to the uphill in addition to wheel rolling resistance and air resistance. It is difficult for the driver to feel uncomfortable that the feeling is poor. Therefore, according to the fourth aspect of the present invention, fuel efficiency is improved by positively executing the free-run control while suppressing the uncomfortable feeling caused by the free-run control on an uphill traveling road. Is possible.

Further, it is an gist of the fifth aspect of the present invention, there is provided a travel control device for the first shot light vehicle, the free-run control start-time target vehicle deceleration is, the free-run control is started in the coasting It is characterized by determining whether or not to execute the free-run control as the previous vehicle deceleration. In this way, by detecting the vehicle deceleration before the start of the free-run control, the target vehicle deceleration for determining whether or not to execute the free-run control can be obtained. It can be determined whether or not to execute the free-run control.

According to a sixth aspect of the present invention, there is provided a vehicle travel control apparatus according to any one of the first to fifth aspects, wherein: (a) the vehicle includes an electric motor that generates a vehicle braking force. (B) When the free run control is started, the vehicle braking force of the electric motor is controlled so that the actual vehicle deceleration approaches the target vehicle deceleration during the free run control. And In this way, when the free-run control is started, it is possible to reduce the sense of discomfort by giving the driver a feeling of deceleration with the vehicle braking force of the electric motor.

Here, preferably, in the vehicle travel control device according to any one of the first invention to the fifth invention, (a) the vehicle includes an electric motor coupled to the drive wheels; (B) In the free run control, the torque of the motor is made zero.

It is a figure which shows notionally the structure of the drive system which concerns on the hybrid vehicle which is one Example of this invention. It is a functional block diagram of Example 1 for demonstrating the principal part of the control function with which the electronic control apparatus of FIG. 1 was equipped. The vehicle deceleration estimation means included in the electronic control unit of FIG. 2 is used to estimate the free-run estimated vehicle deceleration, and experimentally obtained in advance the free-run estimated vehicle deceleration, the gradient of the travel path, and the vehicle speed. It is the figure which showed the set and set relationship. FIG. 3 is a diagram showing a relationship between a target vehicle deceleration at the start of free run and a vehicle speed V on a flat ground in the control of the electronic control unit of FIG. 2. FIG. 3 is a diagram illustrating a relationship between a target vehicle deceleration at the start of free run at a certain vehicle speed and a gradient of a travel path in the control of the electronic control unit of FIG. 2. FIG. 5 is a flowchart of a second embodiment for explaining a main part of a control operation of the electronic control device of FIG. 2, that is, a control operation for executing free-run control. It is a functional block diagram of Example 2 for demonstrating the principal part of the control function with which the electronic control apparatus of FIG. 1 was equipped. FIG. 9 is a flowchart of a second embodiment for explaining a main part of the control operation of the electronic control device of FIG. 7, that is, a control operation for executing vehicle deceleration control during coasting. FIG. 2 is a schematic skeleton diagram of a hybrid vehicle to which the present invention is applied, different from the hybrid vehicle of FIG. 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram conceptually showing the structure of a drive system relating to a hybrid vehicle 8 (hereinafter also simply referred to as “vehicle 8”) according to an embodiment of the present invention. A hybrid vehicle 8 shown in FIG. 1 includes a vehicle drive device 10 (hereinafter referred to as “drive device 10”), a differential gear device 21, a pair of left and right axles 22, a pair of left and right drive wheels 24, and a hydraulic control circuit. 34, an inverter 56, and an electronic control unit 58. The drive device 10 functions as a driving power source for driving and is an engine 12 such as a known gasoline engine or diesel engine, and engine output control for performing engine output control such as starting or stopping of the engine 12 or throttle control. The apparatus 14 includes an electric motor MG that is an electric motor for driving that functions as a driving power source for driving, an engine intermittent clutch K0, a torque converter 16, and an automatic transmission 18. As shown in FIG. 1, the vehicle 8 has a power generated by one or both of the engine 12 and the electric motor MG, the torque converter 16, the automatic transmission 18, the differential gear device 21, and a pair of left and right axles. 22 is configured to be transmitted to a pair of left and right drive wheels 24 via each. Therefore, the vehicle 8 can selectively travel between the engine travel that travels with the power of the engine 12 and the EV travel (motor travel) that stops the engine 12 and travels exclusively with the power of the electric motor MG. it can. In the engine running, the electric motor MG may generate assist torque depending on the running state.

  The electric motor MG is connected to the drive wheels 24, and is, for example, a three-phase synchronous motor, and functions as a motor (motor) that generates power and a generator (generator) that generates reaction force. A motor generator. For example, the electric motor MG generates a vehicle braking force by regenerative operation.

  The power transmission path between the engine 12 and the electric motor MG is provided with an engine intermittent clutch K0 which is a generally known wet multi-plate hydraulic friction engagement device. The engine interrupting clutch K0 functions as a power interrupting device that operates with the hydraulic pressure supplied from the hydraulic control circuit 34 and selectively interrupts power transmission between the engine 12 and the drive wheels 24. Specifically, an engine output shaft 26 (for example, a crankshaft), which is an output member of the engine 12, is connected to the rotor 30 of the electric motor MG so as not to rotate relative to the engine 30 by engaging the engine intermittent clutch K0. The clutch K0 is disengaged from the rotor 30 of the electric motor MG. In short, the engine output shaft 26 is selectively connected to the rotor 30 of the electric motor MG via the engine intermittent clutch K0. Therefore, the engine intermittent clutch K0 is engaged during the engine travel and is released during the motor travel. Further, the rotor 30 of the electric motor MG is connected to a pump impeller 16p, which is an input member of the torque converter 16, so as not to be relatively rotatable.

  The automatic transmission 18 constitutes a part of a power transmission path between the torque converter 16 and the drive wheels 24, and transmits the power of the engine 12 or the electric motor MG to the drive wheels 24. The automatic transmission 18 is a stepped automatic transmission that performs clutch-to-clutch shift by changing the engagement elements in accordance with a preset relationship (shift diagram). In other words, the automatic transmission 18 is an automatic transmission mechanism in which any one of a plurality of predetermined shift speeds (speed ratios) is alternatively established, and in order to perform such a shift, A planetary gear unit and a plurality of clutches or brakes operated by hydraulic pressure from the hydraulic control circuit 34 are provided.

  The torque converter 16 is a fluid transmission device interposed between the electric motor MG and the automatic transmission 18. The torque converter 16 includes a pump impeller 16p that is an input side rotating element, a turbine impeller 16t that is an output side rotating element, and a stator impeller 16s. The torque converter 16 transmits the power input to the pump impeller 16p to the turbine impeller 16t via a fluid (hydraulic oil). The stator impeller 16s is connected to a transmission case 36, which is a non-rotating member, via a one-way clutch. The torque converter 16 includes a lock-up clutch LU that selectively connects the pump impeller 16p and the turbine impeller 16t directly to each other between the pump impeller 16p and the turbine impeller 16t. The lockup clutch LU is controlled by the hydraulic pressure from the hydraulic control circuit 34.

  In the hybrid vehicle 8, for example, when shifting from the motor travel to the engine travel, the engine speed Ne is increased by the engagement of the engine intermittent clutch K <b> 0 and the engine 12 is started.

  Further, when the vehicle is being decelerated with the foot brake depressed, or during inertial driving in which the vehicle braking operation and acceleration operation by the driver are released, the electronic control unit 58 causes the electric vehicle MG to regenerate the traveling vehicle 8. Electric motor regeneration control for supplying the regenerative energy obtained by braking to the power storage device 57 is performed. Specifically, in the motor regeneration control, the power transmission between the engine 12 and the drive wheel 24 is interrupted by releasing the engine intermittent clutch K0, the engine 12 is stopped, and the electric motor MG is driven by the inertial energy of the vehicle 8. Regenerative operation is performed. Then, the inertia energy is regenerated as electric power and charged from the electric motor MG to the power storage device 57. During the execution of the motor regeneration control, the lockup clutch LU is engaged. In addition, during the inertia traveling, the electronic control unit 58 uses the engine intermittent clutch K0 instead of the motor regeneration control depending on the traveling state of the vehicle 8 in order to improve the fuel consumption. And free-run control for stopping the engine 12 is executed. The free-run control does not aim to perform vehicle braking in order to regenerate electric power, so the motor MG does not perform vehicle braking, and the torque Tmg (hereinafter referred to as motor torque Tmg) of the motor MG is made zero. Is preferred. That is, it is preferable that the electric motor MG is idled. In this way, the vehicle 8 is caused to run idle by executing the above-described free-run control. However, the motor torque Tmg may be slightly generated so as to generate a running resistance in a pseudo manner during the execution of the free run control.

  The vehicle 8 includes a control system as exemplified in FIG. The electronic control device 58 shown in FIG. 1 includes a function as a vehicular travel control device that performs control related to the travel of the vehicle 8, and includes a so-called microcomputer. As shown in FIG. 1, the electronic control unit 58 is supplied with various input signals detected by each sensor provided in the hybrid vehicle 8. For example, a signal indicating the accelerator opening degree Acc, which is the depression amount of the accelerator pedal 71 detected by the accelerator opening sensor 60, and a rotation speed (motor rotation speed) Nmg of the motor MG detected by the motor rotation speed sensor 62 are represented. Signal, a signal representing the rotational speed (engine rotational speed) Ne of the engine 12 detected by the engine rotational speed sensor 64, a rotational speed of the turbine impeller 16t of the torque converter 16 detected by the turbine rotational speed sensor 66 (turbine A signal representing the vehicle speed V detected by the vehicle speed sensor 68, a signal representing the throttle opening θth of the engine 12 detected by the throttle opening sensor 70, and the signal obtained from the power storage device 57 A signal representing the remaining charge (charged state) SOC of the power storage device 57, the acceleration sensor 72 A signal representing the vehicle acceleration in the front-rear direction of the vehicle 8 detected by the electronic control unit 58 is input to the electronic control unit 58. Here, the motor rotation speed Nmg detected by the motor rotation speed sensor 62 is the input rotation speed of the torque converter 16, and corresponds to the rotation speed (pump rotation speed) Np of the pump impeller 16p in the torque converter 16. . The turbine rotational speed Nt detected by the turbine rotational speed sensor 66 is the output rotational speed of the torque converter 16, and the rotational speed Natin of the transmission input shaft 19 in the automatic transmission 18, that is, the transmission input rotational speed. Corresponds to Natin. The rotational speed Natout of the output shaft 20 (hereinafter referred to as the transmission output shaft 20) of the automatic transmission 18, that is, the transmission output rotational speed Natout corresponds to the vehicle speed V. In this embodiment, the vehicle acceleration and the vehicle deceleration are both changes in the vehicle speed V per unit time and can take either positive or negative values. However, while the vehicle acceleration takes the acceleration direction as the positive direction, In the vehicle deceleration, the deceleration direction is the positive direction.

  Various output signals are supplied from the electronic control device 58 to each device provided in the hybrid vehicle 8.

  Further, the vehicle 8 includes a navigation system 80 (hereinafter referred to as a navigation 80) as shown in FIG. The navigation 80 includes a storage medium 82 such as a CD-ROM, DVD-ROM, or HDD (hard disk drive), for example, and has a function of executing known navigation control using road map information stored in the storage medium 82. Have. In the road map information, as is generally known, an actual road is represented by links as a plurality of sections divided by a plurality of nodes and connecting the nodes. For each link, a link ID (road number) is determined in order to distinguish each link. In addition, for each link ID, the start point and end point coordinates defined by the node, the average curvature radius and road length and road gradient and altitude as road information, road types such as general roads, expressways and one-way streets, intersections And information on each node such as a passing point on a straight road are stored in the storage medium 82, and information for each link ID is also included in the road map information. Further, the storage medium 82 is configured such that the electronic control device 58 can read the road map information.

  FIG. 2 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 58. As shown in FIG. 2, the electronic control unit 58 includes an inertia travel determination unit 90 as an inertia travel determination unit, a vehicle deceleration estimation unit 92 as a vehicle deceleration estimation unit, and a target as a target vehicle deceleration determination unit. The vehicle deceleration determination means 94, the vehicle deceleration determination means 96 as a vehicle deceleration determination part, and the free run control execution means 98 as a free run control execution part are provided.

  The inertia traveling determination means 90 determines whether or not the vehicle 8 is traveling inertia. The inertia traveling means that the vehicle 8 travels in a state where both the vehicle braking operation and the acceleration operation by the driver are released, the engine intermittent clutch K0 is engaged, and the vehicle 8 is applied with a so-called engine brake. Accordingly, the inertial running determination means 90 is such that when the vehicle braking operation and the acceleration operation are both released, the engine intermittent clutch K0 is engaged, and the vehicle 8 is traveling, the vehicle 8 is inertially traveling. Judge that it is inside. Although the electric motor regeneration control may be executed during the inertia traveling, it does not matter whether the electric motor regeneration control is executed. The case where the vehicle braking operation is released is, for example, a case where the brake is off when the foot brake is not depressed. The case where the acceleration operation is released is, for example, a case where the accelerator is off when the accelerator pedal 71 is not depressed. Further, during high-speed driving, the driver may maintain a slight accelerator opening Acc in order to weaken the so-called engine brake. In this way, a slight accelerator opening is required in order to weaken the engine brake (driving load of the drive system). The case where the speed Acc is maintained and the vehicle speed V gradually decreases due to running resistance is also included when the acceleration operation is released.

The vehicle deceleration estimating means 92, when the inertial running determination means 90 determines that the vehicle 8 is inertially running, when the freerun control is started before the freerun control is started. Estimated vehicle deceleration GFrd (hereinafter referred to as free-run estimated vehicle deceleration GFrd). In other words, the free-run estimated vehicle deceleration GFrd is an estimated vehicle deceleration immediately after the start of the free-run control. The free-run estimated vehicle deceleration GFrd has a vehicle deceleration direction as a positive direction, and its unit is, for example, m / s ² . The vehicle 8 after the start of the free run control is decelerated by the running resistance, and the running resistance is the sum of the air resistance, the gradient resistance, and the rolling resistance of the wheels (the driving wheel 24 and the driven wheel). The estimated vehicle deceleration GFrd can be calculated based on the gradient of the travel path and the vehicle speed V if the gradient of the travel path on which the vehicle 8 travels and the vehicle speed V are known. In this embodiment, the relationship between the free-run estimated vehicle deceleration GFrd, the gradient of the travel path, and the vehicle speed V is experimentally obtained and set in advance as shown in FIG. Calculates the free-run estimated vehicle deceleration GFrd from the preset relationship shown in FIG. 3 based on the gradient of the travel path and the vehicle speed V. That is, the estimated vehicle deceleration GFrd at the time of free run is estimated. In FIG. 3, since the air resistance and rolling resistance increase as the vehicle speed V increases, the estimated vehicle deceleration GFrd during free run increases. Further, as the gradient of the travel path increases in the downward direction, the gradient resistance decreases, so that the free-run estimated vehicle deceleration GFrd decreases. Note that the gradient of the travel road may be obtained from the road map information used by the navigation 80 or may be detected by sensors included in the vehicle 8.

  The target vehicle deceleration determining means 94, when the inertia traveling determination means 90 determines that the vehicle 8 is inertial traveling, before the free run control is started, A vehicle deceleration Grdt (hereinafter referred to as a free-run start target vehicle deceleration Grdt) is determined. Here, the driver expects the vehicle 8 to decelerate due to the engine brake and the running resistance while the vehicle 8 is coasting, and the target vehicle deceleration Grdt at the start of the free run is expected by the driver during the coasting. It is experimentally determined in advance so that the vehicle deceleration at which a feeling of deceleration can be obtained. Therefore, since the target vehicle deceleration Grdt at the start of free run is experimentally determined in accordance with the vehicle deceleration expected by the driver during inertial driving, the request requested by the driver at the start of the free run control. It can be said that this is vehicle deceleration.

  Specifically, in this embodiment, the relationship between the target vehicle deceleration Grdt at the start of the free run, the gradient of the travel path on which the vehicle 8 travels, and the vehicle V is experimentally determined in advance as shown in FIGS. It has been. FIG. 4 shows the relationship between the target vehicle deceleration Grdt at the start of free run and the vehicle speed V on a flat ground (gradient = 0 deg), and FIG. 5 shows the target vehicle deceleration Grdt at the start of free run at a certain vehicle speed V. This represents the relationship with the gradient of the travel path. In FIG. 4, the higher the vehicle speed V, the smaller the free-run start target vehicle deceleration Grdt. The driver has a running sensation that the higher the vehicle speed V, the faster the automatic transmission 18 is shifted to the higher gear speed and the engine brake becomes ineffective, so that the vehicle 8 decelerates as the vehicle speed V increases. It is because it will not expect. In FIG. 5, the free-run start target vehicle deceleration Grdt decreases as the descending slope of the travel path increases. This is because the gradient resistance decreases as the descending gradient of the travel path increases, and the driver does not expect the vehicle 8 to decelerate. As described above, the target vehicle deceleration determination means 94 is based on the predetermined relationship shown in FIGS. 4 and 5 based on the vehicle speed V and the gradient of the travel path before the free run control is started. The target vehicle deceleration Grdt at the start of the free run is determined. The vehicle speed V and the gradient of the travel path on which the target vehicle deceleration Grdt at the start of free run is determined are determined based on the vehicle speed V and the vehicle speed V on which the vehicle deceleration estimation means 92 estimates the free vehicle estimated speed GFrd. It is preferably the same as the gradient of the travel path.

  Further, the target vehicle deceleration determining means 94, when the travel path on which the vehicle 8 travels is an uphill, is not related to the predetermined relationship shown in FIGS. The target vehicle deceleration Grdt is determined to be the same value as the free-run estimated vehicle deceleration GFrd estimated by the vehicle deceleration estimating means 92. In this way, when the traveling road is an uphill grade, the determination of the vehicle deceleration determining means 96 described later is affirmed, and when the running road is not an uphill slope, that is, downhill or flat. This is because the free-run control is easier to execute. Note that the case where the traveling road has an upward slope may be a case where the slope of the traveling road is larger than zero with the upward direction as a positive direction. This is a case where the slope is an ascending slope that is equal to or higher than a predetermined slope where resistance can be felt.

  The vehicle deceleration judgment unit 96 calculates the free-run estimated vehicle deceleration GFrd estimated by the vehicle deceleration estimation unit 92 and the free-run start target vehicle deceleration Grdt determined by the target vehicle deceleration determination unit 94. A deceleration obtained by obtaining the absolute value of the vehicle deceleration difference DGrd (= GFrd−Grdt), which is the difference DGrd between the estimated vehicle deceleration GFrd during free run and the target vehicle deceleration Grdt at the start of free run. It is determined whether or not the difference determination value DG1rd is smaller. Whether or not the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference determination value DG1rd is a condition for starting execution of the free-run control. That is, the vehicle deceleration determination means 96 is under an execution start condition that the free-run control is more easily performed as the free-run estimated vehicle deceleration GFrd is closer to the free-run start target vehicle deceleration Grdt. It can be said that it is determined whether to execute the free-run control. In other words, when the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference judgment value DG1rd, the estimated vehicle deceleration GFrd at the time of free run is This means that the free run control is executed when the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference judgment value DG1rd. It can be said that the closer the estimated vehicle deceleration GFrd is to the target vehicle deceleration Grdt at the start of free run, the easier the free run control is performed. The deceleration difference determination value DG1rd is experimentally determined in advance so that the driver does not feel that the feeling of deceleration is poor when the free-run control is executed and the free-run control is easily executed. ing.

  The free-run control execution means 98 cuts off the power transmission between the engine 12 and the drive wheels 24 and stops the engine 12 by the engine intermittent clutch K0 during the coasting according to the determination of the vehicle deceleration determination means 96. The free run control is executed. In the free-run control, the engine intermittent clutch K0 is released and the engine 12 is stopped. In this embodiment, the motor MG is idled during the execution of the free run control. Specifically, the free-run control execution means 98 determines that the free-run control execution means 98 determines that the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference determination value DG1rd. Execute control. On the other hand, when it is determined that the absolute value of the vehicle deceleration difference DGrd is equal to or greater than the deceleration difference determination value DG1rd, the free run control is not executed. For example, in that case, the motor regeneration control may be executed without executing the free run control.

  In addition, when the free run control execution means 98 starts executing the free run control, when an acceleration operation (accelerator on) is performed, for example, when the accelerator pedal 71 is subsequently depressed, the free run control is executed. finish.

  Here, as described above, the target vehicle deceleration determination means 94 determines the target vehicle deceleration at the start of free run from the predetermined relationship shown in FIGS. 4 and 5 before the free run control is started. Although Grdt is determined, the vehicle deceleration is detected by the acceleration sensor 72 before, for example, the free-run control during the inertial running is started (immediately before) without following FIG. 4 and FIG. The target vehicle deceleration Grdt at the start of the run may be the vehicle deceleration before the start of free-run control during inertial traveling. If it is before the start of the free-run control during inertial driving, the vehicle deceleration at that time is considered to be the vehicle deceleration expected by the driver, for example, the drive system acts as a driving load. is there. As such, if the target vehicle deceleration determining means 94 determines the target vehicle deceleration Grdt at the start of free run, the vehicle deceleration determining means 96 determines that the target vehicle deceleration Grdt at the start of free run is the above inertial running. It is determined whether or not to execute the free-run control on the assumption that the vehicle deceleration before the start of the free-run control.

  FIG. 6 is a flowchart for explaining a main part of the control operation of the electronic control unit 58, that is, a control operation for executing the free-run control. For example, the control operation is repeated with a very short cycle time of about several milliseconds to several tens of milliseconds. Executed. For example, the control operation shown in FIG. 6 is started when the free-run control is not yet executed. The control operation shown in FIG. 6 is executed alone or in parallel with other control operations.

  First, in step (hereinafter, “step” is omitted) SA1 in FIG. 6, it is determined whether or not the vehicle 8 is coasting. If the determination of SA1 is affirmative, that is, if the vehicle 8 is coasting, the process proceeds to SA2. On the other hand, if the determination of SA1 is negative, the process proceeds to SA6. SA1 corresponds to the inertia running determination means 90.

  In SA2 corresponding to the vehicle deceleration estimation means 92, the vehicle speed V and the gradient of the travel path are detected and acquired. Then, assuming that the free-run control is executed, the estimated vehicle deceleration GFrd when the free-run control is started, that is, the estimated vehicle deceleration GFrd at the time of free-run is calculated as the vehicle speed V and the travel path. And the slope of the. After SA2, the process proceeds to SA3.

  In SA3 corresponding to the target vehicle deceleration determining means 94, the vehicle speed V and the gradient of the travel path are acquired and the like, and the target vehicle deceleration Grdt at the start of the free run is determined as the vehicle speed V and the travel. Based on the slope of the road, it is determined from the predetermined relationship shown in FIGS. Here, the target vehicle deceleration Grdt at the start of the free run may be immediately calculated based on the vehicle speed V and the gradient of the travel path, or based on the vehicle speed V, a predetermined relationship shown in FIG. First, the value on the flat ground is calculated first, and the value on the flat ground may be calculated after being corrected according to the predetermined relationship shown in FIG. 5 based on the gradient of the traveling road. In addition, when the travel path on which the vehicle 8 travels is an uphill slope, the target vehicle deceleration Grdt at the start of the free run is equal to SA2 regardless of the predetermined relationship shown in FIGS. It is determined to be the same value as the estimated vehicle deceleration GFrd at the time of free run.

  Also, in SA3, the target vehicle deceleration Grdt at the start of free run does not follow the above-described FIG. 4 and FIG. 5, for example, assuming that the free run control is executed, The vehicle deceleration detected before (just before) the start of control may be used. In such a case, the gradient of the traveling road may or may not be removed from the above-mentioned upward gradient. After SA3, the process proceeds to SA4.

  In SA4 corresponding to the vehicle deceleration determination means 96, the difference DGrd between the free-run estimated vehicle deceleration GFrd estimated in SA2 and the free-run start target vehicle deceleration Grdt determined in SA3. A vehicle deceleration difference DGrd is calculated, and it is determined whether or not the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference determination value DG1rd. If the determination at SA4 is affirmative, that is, if the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference determination value DG1rd, the process proceeds to SA5. On the other hand, if the determination at SA4 is negative, the operation proceeds to SA6.

  In SA5, the free run control is executed. On the other hand, in SA6, the free run control is not executed. SA5 and SA6 correspond to the free-run control execution means 98.

  According to the above-described embodiment, the free-run start target vehicle deceleration Grdt is determined based on the vehicle speed V before the free-run control is started, and the free-run estimated vehicle deceleration GFrd. Is estimated. The free-run control is executed when the absolute value of the vehicle deceleration difference DGrd (= GFrd−Grdt) is smaller than the deceleration difference determination value DG1rd. That is, it can be said that the free-run control is more easily performed as the free-run estimated vehicle deceleration GFrd is closer to the free-run start target vehicle deceleration Grdt. If the free-run control is executed in this way, when the free-run control is executed, a vehicle deceleration close to the free-run start target vehicle deceleration Grdt, for example, a request requested by the driver Since it is considered that a vehicle deceleration close to the vehicle deceleration is easily obtained, even if the free-run control is executed, it is possible to reduce a sense of incongruity that occurs to the driver that the feeling of deceleration is poor. In the free-run control, the engine 12 does not become a traveling load, so that the fuel consumption of the vehicle 8 is improved as compared with the case where the power transmission between the engine 12 and the drive wheels 24 is not interrupted during the inertia traveling. It is possible. That is, it is possible to improve fuel efficiency by executing the free run control while suppressing deterioration of drivability during inertial running.

  Further, since the estimated vehicle deceleration GFrd at the time of free run is estimated before the free run control is started, it is determined whether or not to execute the free run control. It is avoided that the free-run control is immediately stopped because the vehicle deceleration to be performed is inappropriate. Therefore, frequent engine start can be reduced, and energy loss due to engine start can be suppressed.

  Further, according to the present embodiment, the free-run control execution means 98 is determined when the vehicle deceleration determination means 96 determines that the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference determination value DG1rd. The free run control is executed. Accordingly, the fact that the free run control is executed when the estimated vehicle deceleration GFrd at the time of free run is close to the target vehicle deceleration Grdt at the start of free run can be easily performed using the deceleration difference judgment value DG1rd. It is possible to realize.

  Further, according to the present embodiment, the vehicle deceleration estimating means 92 estimates the free-run estimated vehicle deceleration GFrd based on the gradient of the travel path on which the vehicle 8 travels. The target vehicle deceleration determining means 94 determines the free-run start target vehicle deceleration Grdt based on the gradient of the travel path. Here, the vehicle deceleration during inertial traveling changes according to the gradient of the travel path. Therefore, it is possible to appropriately determine whether or not to execute the free-run control as compared with a case where the gradient of the travel path is not taken into consideration.

  Further, according to the present embodiment, as shown in FIG. 5, the free-run start target vehicle deceleration Grdt decreases as the descending slope of the travel path increases. Here, the greater the descending slope of the travel path, the easier the vehicle 8 is accelerated by the slope, so the driver does not expect a large vehicle deceleration. Therefore, it is possible to determine the free-run start target vehicle deceleration Grdt in accordance with the feeling of deceleration that the driver expects on a downhill traveling road.

  Further, according to the present embodiment, the target vehicle deceleration determination means 94 does not depend on the predetermined relationship shown in FIG. 4 and FIG. 5 when the travel path on which the vehicle 8 travels is an uphill. The free-run start target vehicle deceleration Grdt is determined to be the same value as the free-run estimated vehicle deceleration GFrd estimated by the vehicle deceleration estimation means 92. Then, the vehicle deceleration difference DGrd becomes zero, and it is determined that the absolute value of the vehicle deceleration difference DGrd is smaller than the deceleration difference determination value DG1rd. The free-run control is easily performed as compared with the case where the travel path is not an uphill slope. Here, when the free-run control is executed during coasting on the uphill traveling road, the vehicle 8 decelerates due to the uphill in addition to the rolling resistance and air resistance of the wheels. It is difficult for the driver to feel uncomfortable that the feeling of deceleration is poor. Therefore, it is possible to improve fuel efficiency by positively executing the free run control while suppressing the uncomfortable feeling caused by the free run control on an uphill traveling road.

  Further, according to the present embodiment, the vehicle deceleration determination means 96 assumes that the target vehicle deceleration Grdt at the start of free run is the vehicle deceleration before the start of free run control during the inertia running, and the free run It may be determined whether or not to execute control. If so, the free-run start target vehicle deceleration Grdt for determining whether to execute the free-run control is detected by detecting the vehicle deceleration before the free-run control is started. Therefore, it is possible to determine whether or not to execute the free-run control in a simple and appropriate manner.

  Next, another embodiment of the present invention will be described. In the following description, parts common to the embodiments are denoted by the same reference numerals and description thereof is omitted.

  In this embodiment (second embodiment), the electronic control device 58 of the first embodiment is replaced with an electronic control device 160. In the first embodiment, the control for determining whether or not to execute the free run control has been mainly described. In the second embodiment, the control after the start of the free run control will be mainly described. FIG. 7 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 160. As shown in FIG. 7, the electronic control device 160 includes a free run determination unit 164 as a free run determination unit, a target vehicle deceleration determination unit 166 as a target vehicle deceleration determination unit, and an electric motor as a motor torque control unit. Torque control means 168.

  The free run determination means 164 in FIG. 7 determines whether or not the free run control has been started. For example, when the free run control execution means 98 of the first embodiment starts the free run control, it is determined that the free run control is started. Further, it may be determined from the operating state of the engine 12, the operating state of the engine intermittent clutch K0, the motor torque Tmg, and the like.

  The target vehicle deceleration determining means 166 detects the vehicle speed V from the vehicle speed sensor 68 when the free-run determining means 164 determines that the free-run control is started, and travels the vehicle position from the road map information. Get the slope of the road. Then, based on the vehicle speed V and the gradient of the travel path, a predetermined motor deceleration target vehicle deceleration that is a vehicle deceleration target value for determining the motor torque Tmg corresponding to the vehicle braking force of the motor MG. Determine Grdmgt. The target vehicle deceleration Grdmgt for electric motor control is the target at the start of the free run in that it is experimentally determined in advance so as to obtain a vehicle deceleration that provides a deceleration feeling expected by the driver during inertial driving. This is the same as the vehicle deceleration Grdt, except that the vehicle speed V that is the basis for the determination and the acquisition timing of the gradient of the travel path are after the start of the free-run control. In short, the target vehicle deceleration Grdmgt for motor control is the target vehicle deceleration during the free-run control. The target vehicle deceleration determining means 166 is the same as the above-described target vehicle deceleration for motor control, in the same manner as the target vehicle deceleration determining means 94 of the first embodiment determines the free vehicle start target vehicle deceleration Grdt. Determine Grdmgt. For example, the target vehicle deceleration determination means 166 first replaces the vertical axis in FIG. 4 with the motor control target vehicle deceleration Grdmgt, and from the predetermined relationship of FIG. The vehicle deceleration Grdmgt is determined based on the vehicle speed V. Then, the target vehicle deceleration determining means 166 replaces the vertical axis with the motor control target vehicle deceleration Grdmgt in FIG. According to the determined relationship, the motor control target vehicle deceleration Grdmgt obtained from FIG. 4 is corrected so that the motor control target vehicle deceleration Grdmgt becomes smaller as the descending slope becomes larger. At this time, since the driver does not expect the feeling of deceleration during coasting on the down slope as much as the flat ground, the target vehicle deceleration Grdmgt for motor control on the down slope is always higher than the target vehicle deceleration Grdmgt for motor control on the flat ground. Get smaller.

  On the other hand, the target vehicle deceleration determining means 166 detects the current actual vehicle deceleration by the acceleration sensor 72 when the gradient of the travel path is an upward gradient, and the motor control target vehicle deceleration Grdmgt. Is determined to be the same value as the detected actual vehicle deceleration. In this way, when the travel path is an uphill slope, the motor torque control means 168 described later is configured so that the motor control target vehicle deceleration Grdmgt is the actual vehicle deceleration in the vehicle deceleration control described later. As a result, the motor torque Tmg is controlled. In short, the electric motor torque control means 168 sets the electric motor torque Tmg to zero in the upward gradient. The case where the gradient of the travel path is an upward slope may be a case where the slope of the travel path is greater than zero with the upward direction as a positive direction. This is a case where the gradient is higher than a predetermined gradient enough to feel the gradient resistance.

  When the target vehicle deceleration determination unit 166 determines the motor control target vehicle deceleration Grdmgt, the motor torque control unit 168 determines that the actual vehicle deceleration detected by the acceleration sensor 72 is the motor control target. Vehicle deceleration control for controlling the motor torque Tmg so as to approach the vehicle deceleration Grdmgt is executed. The electric motor torque Tmg corresponds to the vehicle braking force of the electric motor MG. For example, in the vehicle deceleration control, the motor torque control means 168 calculates a difference obtained by subtracting the actual vehicle deceleration from the motor control target vehicle deceleration Grdmgt, and takes into account the gear ratio of the automatic transmission 18 and the like. Above, the motor torque Tmg is controlled so that the calculated vehicle deceleration difference approaches zero. In the vehicle deceleration control, the electric motor torque Tmg is basically generated in the deceleration direction of the vehicle 8, that is, the regeneration direction, but may be generated in the acceleration direction of the vehicle 8. Further, it is preferable that the lockup clutch LU is engaged during the execution of the vehicle deceleration control. During execution of the vehicle deceleration control, the actual vehicle deceleration is sequentially detected by the acceleration sensor 72, and at the same time, the target vehicle deceleration determination means 166 determines that the target vehicle deceleration Grdmgt for motor control is the vehicle speed V and the travel. It is updated sequentially according to the gradient of the road.

  Further, when the execution of the vehicle deceleration control is started, the electric motor torque control means 168 ends the vehicle deceleration control when an acceleration operation is performed, for example, when the accelerator pedal 71 is depressed thereafter.

  FIG. 8 is a flowchart for explaining a main part of the control operation of the electronic control device 160, that is, a control operation for executing the vehicle deceleration control during inertial traveling, and is extremely short, for example, about several milliseconds to several tens of milliseconds. It is executed repeatedly at cycle time. The control operation shown in FIG. 8 is executed alone or in parallel with other control operations.

  First, in SB1 of FIG. 8, it is determined whether or not the free-run control is started. For example, if the free-run control has been started and has not yet finished, it is determined that the free-run control has been started. When the determination of SB1 is affirmed, that is, when the free-run control is started, the process proceeds to SB2. On the other hand, when the determination of SB1 is negative, this flowchart ends. Note that SB1 corresponds to the free-run determining unit 164. Even if the vehicle deceleration control is executed in SB8, which will be described later, the determination of SB1 does not change from positive to negative for that reason.

  In SB2, the vehicle speed V is detected by the vehicle speed sensor 68, and the gradient of the traveling path at the vehicle position is acquired from the road map information. After SB2, the process proceeds to SB3.

  In SB3, the vertical axis in FIG. 4 is replaced with the motor control target vehicle deceleration Grdmgt, and the motor control target vehicle deceleration Grdmgt on the flat ground is determined from the predetermined relationship in FIG. It is determined based on V. After SB3, the process proceeds to SB4.

  In SB4, it is determined whether or not the gradient of the travel path acquired in SB2 is an uphill, that is, whether or not the travel path is an uphill. If the determination in SB4 is affirmative, that is, if the gradient of the travel path is an upward gradient, the process proceeds to SB5. On the other hand, if the determination at SB4 is negative, the operation proceeds to SB6. The case where the gradient of the travel path is determined to be an upward slope in SB4 may be a case where the gradient of the travel path is larger than zero with the upward direction as the positive direction. This is a case where the driver has an ascending gradient that is equal to or greater than a predetermined gradient (upward is a positive direction) that allows the driver to feel the gradient resistance while the vehicle is traveling.

  In SB5, the motor control target vehicle deceleration Grdmgt determined in SB3 is corrected according to the fact that the gradient of the travel path is an upward gradient. Specifically, the actual actual vehicle deceleration is detected by the acceleration sensor 72, and the motor control target vehicle deceleration Grdmgt is corrected to the same value as the detected actual vehicle deceleration. After SB5, the process proceeds to SB8.

  In SB6, it is determined whether or not the gradient of the travel path acquired in SB2 is a downward slope, that is, whether or not the travel path is a downhill. For example, the case where the gradient of the travel road is determined to be a downward slope in SB6 may be a case where the slope of the travel road is greater than zero with the downward direction as a positive direction. This is a case where the driver has a downward gradient equal to or greater than a predetermined gradient (downward is a positive direction) to the extent that the driver can feel that the gradient resistance is smaller than that of a flat ground during vehicle travel. If the determination at SB6 is affirmative, that is, if the gradient of the travel path is a downward gradient, the process proceeds to SB7. On the other hand, if the determination at SB6 is negative, the operation proceeds to SB8.

  In SB7, the motor control target vehicle deceleration Grdmgt determined in SB3 is corrected according to the fact that the gradient of the travel path is a downward gradient. More specifically, the vertical axis in FIG. 5 is replaced with the target vehicle deceleration Grdmgt for motor control, and according to the predetermined relationship of FIG. The target vehicle deceleration Grdmgt for motor control determined in SB3 is corrected so that the target vehicle deceleration Grdmgt becomes smaller. After SB7, the process proceeds to SB8. SB2 to SB7 correspond to the target vehicle deceleration determination means 166.

  In SB8 corresponding to the motor torque control means 168, the vehicle deceleration control is executed. For example, in the vehicle deceleration control, an actual vehicle deceleration is detected by the acceleration sensor 72, and a difference obtained by subtracting the actual vehicle deceleration from the target motor deceleration Grdmgt for motor control is calculated. Then, the motor torque Tmg is controlled so that the calculated difference approaches zero.

  According to the above-described embodiment, when the free-run control is started, the motor torque control means 168 determines that the actual vehicle deceleration detected by the acceleration sensor 72 is the target vehicle deceleration Grdmgt for motor control. The vehicle deceleration control for controlling the motor torque Tmg so as to approach (target vehicle deceleration during free-run control) is executed. The electric motor torque Tmg corresponds to the vehicle braking force of the electric motor MG. Therefore, when the free-run control is started, the driver can feel a sense of deceleration with the vehicle braking force of the electric motor MG, and the uncomfortable feeling can be reduced. When the travel path is an uphill slope, the motor torque control means 168 determines that the motor control target vehicle deceleration Grdmgt is the actual vehicle deceleration in the vehicle deceleration control. To control. In short, the electric motor torque control means 168 sets the electric motor torque Tmg to zero in the upward gradient. Therefore, since the electric motor MG does not generate vehicle braking force on the uphill traveling road, fuel efficiency can be improved on the uphill traveling road. In addition, even when the motor torque Tmg is set to zero on an uphill traveling road, it is possible to give the driver a feeling of deceleration due to the uphill slope and to suppress the uncomfortable feeling.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  For example, in the above-described first embodiment, the free run control is started during coasting, but the start of the free run control may be simultaneously with the start of coasting or the free run control. May be started after the start of the coasting.

  In the second embodiment, the vehicle 8 is a hybrid vehicle including one electric motor MG. For example, as illustrated in FIG. 9, the vehicle 8 includes two electric motors, that is, a first electric motor MG1 and a second electric motor MG2. The hybrid vehicle 200 may be replaced. In FIG. 9, the hybrid vehicle 200 includes an engine 12, a first electric motor MG1, a planetary gear device 202 as a differential mechanism, a second electric motor MG2, and the like. The power of the engine 12 or the second electric motor MG2 is transmitted from the ring gear R0 of the planetary gear unit 202 to the pair of drive wheels 24 via the differential gear unit 21, the pair of axles 22, and the like in order. The planetary gear device 202 includes a carrier CA0 connected to the engine 12, a sun gear S0 connected to the first electric motor MG1, a ring gear R0 connected to the driving wheel 24 and integrally rotated with the second electric motor MG2, and a ring gear. Each of R0 and sun gear S0 is meshed with a pinion gear P0 that is rotatably supported by carrier CA0. In the planetary gear device 202 configured as described above, the first electric motor MG1 outputs a reaction torque that opposes the engine torque Te, so that power is transmitted from the engine 12 to the drive wheels 24. On the contrary, the first electric motor MG1 is caused to idle so that the power transmission between the engine 12 and the drive wheels 24 is interrupted. That is, in the hybrid vehicle 200, the first electric motor MG1 and the planetary gear device 202 correspond to the power interrupting device of the present invention. The second electric motor MG2 generates a vehicle braking force by regenerative operation. In this inertial traveling of the hybrid vehicle 200, for example, the first electric motor MG1 is idled and the engine 12 is stopped, and a pseudo engine brake is generated by the regenerative operation of the second electric motor MG2.

  In the first embodiment, the vehicle 8 includes the electric motor MG. However, the vehicle 8 may be replaced with an engine vehicle that does not include the electric motor MG. Further, the vehicle 8 may be replaced with the hybrid vehicle 200 shown in FIG.

  In the above-described second embodiment, when the vehicle deceleration control is executed, the vehicle deceleration control may be started at the same time as the free-run control is started. The free run control may be started after a delay.

  Further, in the above-described first embodiment, when the travel path on which the vehicle 8 travels is ascending, the free-run start target vehicle deceleration Grdt is determined to be the same value as the free-run estimated vehicle deceleration GFrd. As a result, the free-run control is easier to execute than when the travel path is not uphill, but the free-run control is performed when the travel path is up-gradient by other methods. It may be easier to implement. For example, when the travel path is an uphill slope, the free run control execution means 98 may execute the free run control regardless of the determination of the vehicle deceleration determination means 96. Alternatively, when the travel path is an uphill slope, the deceleration difference determination value DG1rd is set to a larger value than when it is not an uphill slope so that the free-run control can be easily performed. Good.

  In the first and second embodiments, as shown in FIG. 1, the electric motor MG is connected to the pump impeller 16p of the torque converter 16, but not the pump impeller 16p, the transmission output shaft. It may be connected to 20.

  In the first and second embodiments, the motive power of the engine 12 and the motive power of the electric motor MG are both transmitted to the common drive wheel 24, but the vehicle 8 is connected to one wheel of the front wheel and the rear wheel. The power of the engine 12 may be transmitted and the power of the electric motor MG may be transmitted to the other wheel. In that case, the front wheels and the rear wheels are drive wheels of the vehicle 8.

  In the first and second embodiments, the vehicle 8 includes the automatic transmission 18 as shown in FIG. 1, but the automatic transmission 18 is not essential.

  In the first and second embodiments, the torque converter 16 includes the lockup clutch LU. However, the torque converter 16 may not include the lockup clutch LU. Further, the torque converter 16 is not essential.

  In the above-described first embodiment, SA3 is executed after SA2 in the flowchart of FIG. 6, but the execution order of SA2 and SA3 may be switched. For example, SA2 is executed after SA3. There is no problem.

  In the above-described first embodiment, the free-run control is more easily performed as the free-run estimated vehicle deceleration GFrd is closer to the free-run start target vehicle deceleration Grdt. Whether or not it is easy to execute can be determined by various determination methods. For example, when the vehicle 8 travels on different slopes under the same vehicle speed conditions, the difference between the free-run estimated vehicle deceleration GFrd and the free-run start target vehicle deceleration Grdt (vehicle deceleration difference DGrd) If the number of times that free-run control is executed increases as the value becomes smaller, it is determined that free-run control is easier to execute as the free-run estimated vehicle deceleration GFrd is closer to the target vehicle deceleration Grdt at the start of free-run. it can.

  Further, the plurality of embodiments described above can be implemented in combination with each other, for example, by setting priorities. For example, when the first embodiment and the second embodiment are combined and executed, when the free run control is started in SA5 of the flowchart of FIG. 6, the determination of SB1 of the flowchart of FIG. 8 is affirmative. Is done.

8,200: Hybrid vehicle (vehicle)
12: Engine 24: Drive wheels 58, 160: Electronic control device (vehicle travel control device)
202: Planetary gear device (power interrupting device)
MG: Electric motor K0: Engine intermittent clutch (power intermittent device)
MG1: First electric motor (power interrupter)
MG2: Second electric motor (electric motor)

Claims (6)

A vehicle having a power interrupting device that interrupts power transmission between an engine and a drive wheel, and executing free-run control that interrupts the power transmission by the power interrupting device and stops the engine during inertial running A travel control device for
Before starting the free run control, determine the target vehicle deceleration at the start of the free run control based on the vehicle speed, and estimate the estimated vehicle deceleration at the start of the free run control,
The free run control is executed when the absolute value of the difference between the estimated vehicle deceleration and the target vehicle deceleration at the start of the free run control is smaller than a predetermined deceleration difference judgment value. A vehicle travel control device. Estimating the estimated vehicle deceleration based on the gradient of the travel path on which the vehicle travels;
The vehicle travel control apparatus according to claim 1, wherein a target vehicle deceleration at the start of the free run control is determined based on a gradient of the travel path. The vehicle travel control apparatus according to claim 2 , wherein the target vehicle deceleration at the start of the free-run control is smaller as the descending slope of the travel path is larger. Wherein when the traveling road is an upward slope, as compared to the case where the traveling road is not the up slope, the vehicle according to claim 2 or 3, characterized in that easily the free-run control is executed Travel control device. The target vehicle deceleration at the start of the free run control is determined to be the vehicle deceleration before the start of the free run control during the inertia running, and it is determined whether to execute the free run control. The vehicle travel control device according to claim 1 . The vehicle includes an electric motor that generates a vehicle braking force,
When starting the free running control claims 1-5, characterized in that to control the vehicle braking force of the motor so that the actual vehicle deceleration to approach the target vehicle deceleration in the free-run control The vehicle travel control device according to any one of the above.

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