Control device for hybrid vehicle

Abstract

A control device for a hybrid vehicle includes a setting portion that sets an engine torque and a motor generator torque in accordance with a requested torque and an information collecting portion that collects travel information including current vehicle speed and acceleration of the hybrid vehicle and, in a case where, when the hybrid vehicle is decelerated, an allowable upper limit of the engine torque allowed to be output is larger than the requested torque, the setting portion estimates a vehicle stop transition period, with reference to a deceleration pattern in which is estimated a change of a deceleration with time until the hybrid vehicle traveling at the vehicle speed and at the deceleration indicated by the travel information is stopped, and sets the engine torque to which a charging torque calculated using the vehicle stop transition period is added and a negative motor generator torque corresponding to the charging torque.

Description

CONTROL DEVICE FOR HYBRID VEHICLE

[0001] The present invention relates to a control device for a hybrid vehicle.

[0002] Conventionally, hybrid vehicles that include an engine and a motor generator that are driving sources, and a power storage portion that transmits and receives electric power to and from the motor generator have been known. In such a hybrid vehicle, in order to comply with a requested torque requested at acceleration, in addition to an engine torque, a motor generator torque is output in some cases. Patent Literature 1 discloses a control device that controls a generator motor that is a motor generator.

[0003] Patent Literature 1: JP H7-123509 A

[0004] In order to prevent shortage of a charge amount of a power storage portion, it is a possible measure to, for example, when an allowable upper limit of an engine torque that is allowed to be output is larger than a requested torque in a hybrid vehicle at deceleration, perform charging of the power storage portion while decelerating the hybrid vehicle by setting an engine torque to which a charging torque used for charging the power storage portion is added. At this time, the charging torque should be set in accordance with a vehicle stop transition period until the hybrid vehicle is stopped such that the power storage portion is charged neither too much nor too little when the hybrid vehicle is stopped. However, it is difficult to estimate the vehicle stop transition period, and when the charging torque is set in accordance with the vehicle stop transition period estimated with low accuracy, the power storage portion cannot be sufficiently charged, and a torque assist by the motor generator cannot be ensured, so that there is a concern that a fuel efficiency improvement effect and an exhaust gas reduction effect by the torque assist cannot be continuously obtained. Therefore, a technique capable of increasing accuracy of estimation of the vehicle stop transition period has been desired. Note that, in Patent Literature 1, no consideration is given to setting the engine torque by adding the charging torque in the hybrid vehicle during deceleration.

[0005] The present invention has been devised to solve at least a part of the problem described above, and an object of the present invention is to provide a technology capable of increasing accuracy of estimation of a vehicle stop transition period in a control device of a hybrid vehicle.

[0006] The present invention has been devised to solve at least a part of the problem described above, and can be implemented as the following aspects.

[0007] (1) According an aspect of the present invention, a control device for a hybrid vehicle is provided. The control device is a control device for a hybrid vehicle including an engine and a motor generator that are driving sources and a power storage portion that supplies electric power to the motor generator and stores electric power generated by the motor generator and includes a setting portion that sets an engine torque that is output from the engine and a motor generator torque that is output from the motor generator in accordance with a requested torque requested by the hybrid vehicle and an information collecting portion that collects travel information including at least current vehicle speed and acceleration of the hybrid vehicle, and, in a case where, while the hybrid vehicle is decelerated, an allowable upper limit of the engine torque that is allowed to be output is larger than the requested torque, after estimating, with reference to a deceleration pattern in which change of a deceleration with time until the hybrid vehicle traveling at the vehicle speed and the deceleration that is a negative acceleration, the vehicle speed and the deceleration being indicated by the travel information, is stopped is estimated, a vehicle stop transition period until the hybrid vehicle is stopped and calculating a charging torque used for charging the power storage portion using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets a negative motor generator torque corresponding to the charging torque.

[0008] According to the above-described configuration, the engine torque to which the charging torque is added is set and also the negative motor generator toque corresponding to the charging torque is set while the hybrid vehicle is decelerated, so that the power storage portion can be charged while the hybrid vehicle is decelerated. Moreover, the vehicle stop transition period is estimated with reference to the deceleration pattern, so that accuracy of estimation of the vehicle stop transition period can be increased. Furthermore, the charging torque is calculated using the vehicle stop transition period, so that it is possible to prevent the charge amount of the power storage portion from becoming too much or too little when the hybrid vehicle is stopped. As a result, a torque assist by the motor generator at acceleration is ensured, so that it is possible to continuously achieve the fuel efficiency improvement effect and the exhaust gas reduction effect by the torque assist. It is also possible to avoid consumption of extra fuel due to a decrease in charge and discharge efficiency of the power storage portion that occurs when the current charge amount is excessive.

[0009] (2) In the control device of the above-described aspect, in which, in a case where, when the hybrid vehicle is decelerated at the deceleration smaller than a reference deceleration set as a reference in advance, the allowable upper limit of the engine torque is larger than the requested torque, after estimating the vehicle stop transition period with reference to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit magnification set in advance and calculating the charging torque using the vehicle stop transition period, the setting portion may set the engine torque to which the charging torque is added and set the negative motor generator torque corresponding to the charging torque. According to the above-described configuration, when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration, the charging torque is calculated using the vehicle stop transition period estimated with reference to the lower limit deceleration pattern, so that a secondary battery can be charged more efficiently than when a deceleration pattern based on a deceleration smaller than the reference deceleration is referred to.

[0010] (3) In the control device of the above-described aspect, in a case where, while the hybrid vehicle is accelerated or travels at a constant speed, the allowable upper limit of the engine torque is larger than the requested torque, after estimating the vehicle stop transition period with reference to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit magnification set in advance and calculating the charging torque using the vehicle stop transition period, the setting portion may set the engine torque to which the charging torque is added and set the negative motor generator torque corresponding to the charging torque. According to the above-described configuration, even when the hybrid vehicle is accelerated or travels at a constant speed, the charging torque is calculated using the vehicle stop transition period estimated with reference to the lower limit deceleration pattern, so that the power storage portion can be charged even when the hybrid vehicle is accelerated or travels at a constant speed. Therefore, even when the hybrid vehicle is decelerated at a low frequency, it is possible to prevent the charge amount of the power storage portion form becoming insufficient.

[0011] (4) In the control device of the above-described aspect, the setting portion may calculate the charging torque using a subtracted charge amount obtained by subtracting a current charge amount of the power storage portion and a regenerative charge amount that can be regenerated before the hybrid vehicle is stopped from a target charge amount that is a target of the charge amount of the power storage portion and the vehicle stop transition period. According to the above-described configuration, the charging torque is calculated using the subtracted charge amount in consideration of the regenerative charge amount, so that it is possible to prevent the charge amount of the power storage portion from becoming excessive when the hybrid vehicle is stopped. As a result, it is possible to further avoid consumption of extra fuel due to a decrease in charge and discharge efficiency of the power storage portion that occurs when the charge amount is excessive.

[0012] (5) In the control device of the above-described aspect, the setting portion may be able to refer to the deceleration pattern adjusted in accordance with at least one of a characteristic of the hybrid vehicle, a surrounding environment of the hybrid vehicle during traveling, and a driver who is driving the hybrid vehicle. According to the above-described configuration, it is possible to refer to the deceleration pattern adjusted in accordance with a situation, so that it is possible to further improve the accuracy of estimation of the vehicle stop transition period. Therefore, accuracy of calculation of the charging torque is also increased, so that it is possible to further prevent the charge amount of the power storage portion from becoming too much or too little when the hybrid vehicle is stopped.

[0013] It should be noted that the present invention can be realized in various aspects and, for example, can be realized in aspects of a hybrid vehicle in which the control device is mounted, a control method for controlling the hybrid vehicle, or the like.

[0014] Fig. 1 is an explanatory diagram illustrating an example of a hybrid vehicle including a control device of a first embodiment.Fig. 2 is explanatory graphs illustrating changes of vehicle speed, EG torque, and current charge amount with time.Fig. 3 is explanatory graphs illustrating speed change of the hybrid vehicle until the hybrid vehicle is stopped.Fig. 4 is an explanatory graph illustrating a deceleration pattern used in estimating a vehicle stop transition period.Fig. 5 is an explanatory graph illustrating the vehicle stop transition period when the vehicle is decelerated in accordance with each deceleration pattern.Fig. 6 is an explanatory graph illustrating a regenerative charge amount regenerated when the vehicle is decelerated at a constant deceleration.Fig. 7 is an explanatory graph illustrating that the regenerative charge amount varies in accordance with a value of deceleration.Fig. 8 is a flowchart illustrating steps of torque setting processing of the first embodiment.Fig. 9 is explanatory graphs illustrating changes of vehicle speed and current charge amount with time.Fig. 10 is a flowchart illustrating steps of torque setting processing of a second embodiment.

[0015] Fig. 1 is an explanatory diagram illustrating an example of a configuration of a hybrid vehicle 1 including a control device 20 (details will be described later) of a first embodiment. The hybrid vehicle 1 includes, in addition to the control device 20, an engine 11, a transmission 12, a propeller shaft 13, a differential gear 14, a drive shaft 15, tires 16, a motor generator 17, and a secondary battery 18.

[0016] In the hybrid vehicle 1, an engine torque (which will be hereinafter referred to as an EG torque) that is output from the engine 11 is transmitted as an axle torque to the propeller shaft 13. At power running, a motor generator torque (which will be hereinafter referred to as an MG torque) that is output from the motor generator 17 using electric power supplied from the secondary battery 18 is transmitted as an axle torque to the propeller shaft 13. The axle torque is transmitted as a driving torque to the tires 16 via the differential gear 14 and the drive shaft 15. The engine 11 and the motor generator 17 are driving sources of the hybrid vehicle 1.

[0017] On the other hand, at regeneration, the axle torque is transmitted as the MG torque to the motor generator 17. The MG torque is used for power generation performed by the motor generator 17. Electric power generated by the motor generator 17 is charged to the secondary battery 18. As described above, the secondary battery 18 as a power storage portion supplies electric power to the motor generator 17 at power running and stores electric power generated by the motor generator 17 at regeneration.

[0018] The control device 20 includes a setting portion 21, an EG drive control portion 23, an MG drive control portion 25, and an information collecting portion 27. The setting portion 21 sets the EG torque that is output from the engine 11 and the MG torque that is output from the motor generator 17 in accordance with a requested torque requested by the hybrid vehicle 1. Herein, the requested torque is calculated in accordance with a stepping amount of an accelerator pedal (not illustrated) or a stepping amount of a brake pedal (not illustrated) of the hybrid vehicle 1. The EG drive control portion 23 drives the engine 11 in accordance with the set EG torque. The MG drive control portion 25 drives the motor generator 17 in accordance with the set MG torque. The information collecting portion 27 collects travel information related to the traveling hybrid vehicle 1. The information collecting portion 27 periodically collects travel information while the hybrid vehicle 1 is in operation, and transmits a signal indicating the information to the setting portion 21. The travel information includes, for example, current vehicle speed and acceleration of the hybrid vehicle 1, a current charge amount of the secondary battery 18, a rotation speed of the motor generator 17, or the like. The acceleration acquired by the travel information includes not only a positive acceleration but also a negative acceleration representing a deceleration.

[0019] Fig. 2 is explanatory graphs illustrating changes of the vehicle speed of the hybrid vehicle 1, the EG torque, and the current charge amount CC of the secondary battery 18 with time. (A) of Fig. 2 illustrates change of the vehicle speed of the hybrid vehicle 1 with time. An ordinate in (A) of Fig. 2 represents change of the vehicle speed of the hybrid vehicle 1 and an abscissa in (A) of Fig. 2 represents time. Note that abscissas in (B) and (C) of Figs. 2 that will be described next similarly represent time. (B) of Fig. 2 illustrates change of the EG torque that is output by the engine 11 with time. An ordinate in (B) of Fig. 2 represents the EG torque that is output by the engine 11. In (B) of Fig. 2, a solid line b1 represents the EG torque that changes with time, and a one dot chain line b2 represents the requested torque that changes with time. (C) of Fig. 2 illustrates changes of the current charge amount CC of the secondary battery 18 with time. An ordinate in (C) of Fig. 2 represents the current charge amount CC of the secondary battery 18. A solid line c1 in (C) of Fig. 2 represents the current charge amount CC of the secondary battery 18 that changes with time. A broken line c2 in (C) of Fig. 2 represents a target charge amount ST that is a target of the charge amount of the secondary battery 18. For example, the target charge amount ST is preferably set so that the charge amount remains even after the vehicle is accelerated to a maximum speed in a state where the stepping amount of the accelerator pedal is 100%. A one dot chain line c3 in (C) of Fig. 2 will be described later.

[0020] At a timing t1, when an acceleration request for acceleration to the vehicle speed V (see (A) of Fig. 2) is detected based on an increase in the stepping amount of the accelerator pedal, the requested torque is calculated in accordance with the stepping amount. At this time, the information collecting portion 27 transmits, as the travel information, a signal indicating information, such as, for example, an intake air amount, an intake pipe pressure, a fuel injection amount, a rotation speed, or the like, in the engine 11 to the setting portion 21. The setting portion 21 sets the EG torque to a value equal to or less than an upper limit (allowable upper limit) of the allowable range that satisfies an emission standard of an exhaust gas from the engine 11, based on the information. By this setting, the EG torque starts increasing at the timing t1, as indicated by the solid line b1 in (B) of Fig. 2.

[0021] The allowable range that satisfies the emission standard of the exhaust gas from the engine 11 means an allowable range that satisfies an emission standard of harmful substances, such as nitrogen oxide (NOx), particulate matter (PM), hydrocarbon (HC), carbon monoxide (CO), or the like, in the exhaust gas emitted from the hybrid vehicle 1. The allowable range is calculated using an engine model represented by a physical formula, a numerical map, a neural network, or the like created by a physical model, an experimental formula, or a combination thereof. The allowable range at a next time point is calculated by inputting driving conditions (a rotation speed, a load, or the like) and state quantities (a boost pressure, an EGR rate, or the like) at a current time to the engine model. Note that a method of setting the allowable range is not limited to a method using the engine model, and an arbitrary method may be used.

[0022] The EG torque in a period from the timing t1 to a timing t3 is the EG torque of the allowable upper limit. As indicated by the solid line b1 and the one dot chain line b2 in (B) of Fig. 2, the allowable upper limit of the EG torque that is allowed to be outputted is smaller than the requested torque during the period. In this case, the setting portion 21 sets the EG torque that is equal to or less than the allowable upper limit, and then, sets a difference between the EG torque and the requested torque as the MG torque. That is, in the period from the timing t1 to the timing t3, the MG torque is set as an assist of the EG torque that is set to a level equal to or lower than the allowable upper limit. At this time, as indicated by the solid line c1 in (C) of Fig. 2, in the period from the timing t1 to the timing t3, the charge amount of the secondary battery 18 is reduced by an amount corresponding to the MG torque used for assisting the EG torque.

[0023] As the vehicle speed of the hybrid vehicle 1 approaches the vehicle speed V (see (A) of Fig. 2), the stepping amount of the accelerator pedal starts decreasing at a timing t2, so that the requested torque also starts decreasing (see (B) of Fig. 2). Thereafter, at the timing t3, the requested torque that decreases and the EG torque that increases while keeping the allowable upper limit become equal to each other (the solid line b1 and the one dot chain line b2 intersect with each other). At this time, a state of the allowable upper limit of the EG torque and the requested torque shifts to a state where the allowable upper limit is larger than the required torque.

[0024] In a period from a timing t4 to a timing t5, the vehicle speed of the hybrid vehicle 1 is maintained at the vehicle speed V. That is, in this period, the hybrid vehicle 1 travels at a constant speed. When stepping on the accelerator pedal starts at the timing t5, deceleration of the hybrid vehicle 1 is started along with decrease of the EG torque. At this time, the requested torque also starts decreasing to turn to a negative requested torque. While the requested torque is negative, brake regeneration is performed. At the timing t6, the EG torque becomes 0. Then, at a timing t7, the vehicle speed also becomes 0, and thus, the hybrid vehicle 1 is stopped.

[0025] In a period from the timing t5 to the timing t7, a state where, when the hybrid vehicle 1 decelerates, the allowable upper limit of the EG torque is larger than the requested torque is held. At the timing t5, when a deceleration request is detected based on an increase in a stepping amount of a brake pedal, with this as a trigger, the setting portion 21 sets the EG torque to which the charging torque for charging the secondary battery 18 is added in order to perform deceleration regeneration for charging the secondary battery 18 while decelerating the hybrid vehicle 1. In other words, the EG torque set at this time is a torque obtained by adding the charging torque to the torque for driving the hybrid vehicle 1. The setting portion 21 sets a negative MG torque corresponding to the charging torque. The negative MG torque means an MG torque at regeneration in which electric power that is stored in the secondary battery 18 is generated.

[0026] A subtracted charge amount ΔSoC and the vehicle stop transition period f are used for calculating the charging torque. The subtracted charge amount ΔSoC is a charge amount obtained by subtracting the current charge amount CC (see the solid line c1 in (C) of Fig. 2) of the secondary battery 18 and the regenerative charge amount P that can be recovered by the brake regeneration before the hybrid vehicle 1 is stopped from the target charge amount ST (see the broken line c2 in (C) of Fig. 2) that is a target of the charge amount of the secondary battery 18. The one dot chain line c3 in (C) of Fig. 2 represents the charge amount obtained by subtracting only the regenerative charge amount P from the target charge amount ST. That is, the regenerative charge amount P starts having a value after the deceleration is started at the timing t5. Therefore, in the period from the timing t1 to the timing t5, because the regenerative charge amount P does not have a value, the subtracted charge amount ΔSoC is a value obtained by subtracting only the current charge amount CC (the solid line c1) of the secondary battery 18 from the target charge amount ST (the broken line c2) (indicated as an arrow with arrowheads at both ends between the solid line c1 and the broken line c2). On the other hand, in the period from the timing t5 and the timing t7, the subtracted charge amount ΔSoC is a value obtained by further subtracting the current charge amount CC (the solid line c1) of the secondary battery 18 from the charge amount (the one dot chain line c3) obtained by subtracting only the regenerative charge amount P from the target charge amount ST (indicated as an arrow with arrowheads at both ends between the solid line c1 and the one dot chain line c3). As illustrated in (C) of Fig. 2, the subtracted charge amount ΔSoC is 0 at and after the timing t6, and charging is performed only by brake regeneration in a period from the timing t6 to the timing t7. In other words, in the period from the timing t6 to the timing t7, the difference between the target charge amount ST and the current charge amount CC of the secondary battery 18 is equal to the regenerative charge amount P (the solid line c1 and the one dot chain line c3 match). Details of calculation of the regenerative charge amount P will be described later.

[0027] The vehicle stop transition period f used for calculation of the charging torque in addition to the subtracted charge amount ΔSoC is a period until the hybrid vehicle 1 is stopped. The vehicle stop transition period f is estimated by the setting portion 21 with reference to a deceleration pattern illustrated in Fig. 4, and details thereof will be described later. The charging torque is calculated by dividing the subtracted charge amount ΔSoC by the vehicle stop transition period f and the rotation speed of the motor generator 17. Note that the current charge amount CC of the secondary battery 18 and the rotation speed of the motor generator 17 change from moment to moment but can be acquired from the travel information sequentially collected by the information collecting portion 27. The rotation speed of the motor generator 17 used for calculating the charging torque may be a current rotation speed, may be the rotation speed at a next time point calculated in consideration of a current deceleration, or may be an average value of the current rotation speed and the rotation speed at the next time point.

[0028] In the period from the timing t5 to the timing t7, the secondary battery 18 is charged while the hybrid vehicle 1 is decelerated, and then, at the timing t7, the hybrid vehicle 1 is stopped and the requested torque also becomes 0. Note that, in the period from the timing t5 to the timing t6, the EG torque to which the charging torque is added is set, but when the EG torque is larger than the allowable upper limit, the charging torque is preferably adjusted to be equal to or lower than the allowable upper limit.

[0029] Next, estimation of the vehicle stop transition period f will be described with reference to Figs. 3 to 5. Fig. 3 is explanatory graphs illustrating speed change of the hybrid vehicle 1 until the hybrid vehicle is stopped. (A) of Fig. 3 illustrates change of the vehicle speed with time. (B) of Fig. 3 illustrates change of acceleration and deceleration (negative acceleration) with time. An ordinate in (A) of Fig. 3 represents the vehicle speed of the hybrid vehicle 1 and an ordinate in (B) of Fig. 3 represents acceleration and deceleration of the hybrid vehicle 1. Abscissas in (A) and (B) of Figs. 3 represent time.

[0030] As illustrated in (A) and (B) of Figs. 3, in a period P1, a driver reduces the stepping amount of the accelerator pedal (acceleration) as approaching a target vehicle speed while accelerating the hybrid vehicle 1. In a period P2, the driver makes the stepping amount of the accelerator pedal constant (makes the acceleration zero) in order to maintain a constant speed. In a period P3, the driver senses a vehicle stop event (a red light, a stop of a preceding vehicle, or the like) and starts stepping the brake pedal (deceleration). In a period P4, the driver adjusts the stepping amount of the brake pedal (deceleration) toward a stop position. In a period P5, the driver gradually reduces the stepping amount of the brake pedal (deceleration) in order to reduce an impact at a time of stopping the vehicle, and the vehicle is stopped. As illustrated in (B) of Fig. 3, the deceleration at and after the period P3 is not constant and, in a general market driving trend, the deceleration is gentle at start of deceleration (the period P3), the deceleration is increased as approaching to the stopping position (the period P4), and impact relaxation at a time of stopping the vehicle is adjusted immediately before stopping (the period P5).

[0031] In (A) of Fig. 3, when it is assumed that the acceleration (deceleration) at each time point continues to be constant, it is possible to estimate a period from each time point to a time at which the hybrid vehicle 1 is stopped (that is, the vehicle stop transition period f). For example, when an extension line Lc extending along an inclination at the time point Tc is set and also an intersection point Nc at which the extension line Lc intersects with the time axis is set, the vehicle stop transition period f is estimated as a period from the time point Tc to the intersection point Nc. On the other hand, since extension lines La and Lb extending along inclinations of time points Ta and Tb do not intersect with the time axis, the vehicle stop transition period f cannot be estimated (becomes infinite). This means that the vehicle stop transition period f cannot be estimated when the hybrid vehicle 1 is accelerated or travels at a constant speed because it is unknown when the vehicle stop event occurs, and the vehicle stop transition period f can be estimated only when the hybrid vehicle 1 starts decelerating. Note that, as the period shifts from the period P3 to the periods P4 and P5, the vehicle stop transition period f is estimated to be shorter (indicated as a plurality of arrows with arrowheads at both ends between the timing t5 and the timing t7 in (A) of Fig. 2) and, when the vehicle speed becomes 0, the vehicle stop transition period f is also estimated to be 0.

[0032] Fig. 4 is an explanatory graph of a deceleration pattern DP used when the setting portion 21 estimates the vehicle stop transition period f. An ordinate in Fig. 4 represents the deceleration of the hybrid vehicle 1 and an abscissa in Fig. 4 represents the vehicle speed of the hybrid vehicle 1. The deceleration pattern DP is a pattern obtained by estimating change of the deceleration with time until the hybrid vehicle 1 traveling at the vehicle speed and the deceleration indicated by the travel information is stopped. For example, when the vehicle speed and the deceleration of the hybrid vehicle 1 are at a point D on the deceleration pattern DP, it is estimated that the change of the deceleration of the hybrid vehicle 1 with time corresponds to the deceleration pattern DP. The deceleration pattern DP is created by performing market traveling of the vehicle, collecting a plurality of pieces of data in which each vehicle speed (a speed for every 15 km / h of the vehicle speed in this embodiment) and a deceleration at each vehicle speed are associated with each other, and defining, among decelerations corresponding to each vehicle speed, a deceleration larger than 90% of the decelerations as a deceleration at each vehicle speed. The deceleration larger than 90% of the decelerations among the decelerations corresponding to each vehicle speed means, for example, that a deceleration of 2.75 km / s corresponds to a vehicle speed of 60 km / h in the deceleration pattern DP, and the deceleration of 2.75 km / s is a deceleration larger than deceleration values indicated by 90% of data among various deceleration values corresponding to the vehicle speed of 60 km / h in the data accumulated by market traveling. The deceleration pattern DP shows a trend that the deceleration is small when the vehicle speed is relatively high and is large when the vehicle speed is relatively low. The deceleration pattern DP may be stored in the setting portion 21, and may be stored in a separate device that can communicate with the setting portion 21. The separate device may be provided either inside or outside the hybrid vehicle 1.

[0033] The deceleration pattern DPc is a pattern obtained by multiplying a value of the deceleration at each vehicle speed of the deceleration pattern DP by 0.6. For example, when the vehicle speed and the deceleration of the hybrid vehicle 1 are at a point Dc, since the point Dc is not on the deceleration pattern DP, the change of the deceleration of the hybrid vehicle 1 with time cannot be estimated using the deceleration pattern DP. Therefore, in this embodiment, a deceleration pattern DPc passing through the point Dc is created by multiplying the value of the deceleration at each vehicle speed of the deceleration pattern DP by a specific value (0.6 for the deceleration pattern DPc). Of course, any one of the values of the decelerations at the vehicle speeds is multiplied by the same specific value. With reference to the deceleration pattern DPc created in the above-described manner, change of the deceleration of the hybrid vehicle 1 traveling at the vehicle speed and the deceleration indicated at the point Dc with time can be estimated. As described above, in this embodiment, by using the deceleration pattern DP as a reference, creating a deceleration pattern (an example of which is described as the deceleration pattern DP above) that matches the vehicle speed and the deceleration of the hybrid vehicle 1 by multiplying the deceleration pattern DP by a specific value as appropriate in accordance with the vehicle speed and the deceleration of the hybrid vehicle 1, change of the deceleration of the hybrid vehicle 1 traveling at arbitrary vehicle speed and deceleration with time can be estimated.

[0034] Fig. 5 is an explanatory graph illustrating the vehicle stop transition period s of the hybrid vehicle 1 when the hybrid vehicle 1 is decelerated in accordance with each deceleration pattern. A curved line CV indicates the vehicle stop transition period s when the hybrid vehicle 1 is decelerated in accordance with the deceleration pattern DP. As indicated by a point D (corresponding to the point D in Fig. 4), the vehicle stop transition period s when the hybrid vehicle 1 traveling at a vehicle speed of 120 km / h is decelerated in accordance with the deceleration pattern DP is estimated to be about 49 seconds. A curved line CVc indicates the vehicle stop transition period s when the hybrid vehicle 1 is decelerated in accordance with the deceleration pattern DPc (a pattern obtained by multiplying the value of the deceleration at each vehicle speed of the deceleration pattern DP by 0.6). As indicated by a point Dc (corresponding to the point Dc in Fig. 4), the vehicle stop transition period s when the hybrid vehicle 1 traveling at a vehicle speed of 60 km / h is decelerated in accordance with the deceleration pattern DPc is estimated to be about 24 seconds. Each of curved lines CVa, CVb, CVd, and CVe indicates the vehicle stop transition period s when the hybrid vehicle 1 is decelerated in accordance with a corresponding one of deceleration patterns (not illustrated) obtained by multiplying the value of the deceleration at each vehicle speed of the deceleration pattern DP by 0.1, 0.4, 0.8, and 1.2.

[0035] In this embodiment, the setting portion 21 can refer to a deceleration pattern adjusted in accordance with at least one of a characteristic of the hybrid vehicle 1, a surrounding environment of the hybrid vehicle 1 during traveling, and the driver who is driving the hybrid vehicle 1 (hereinafter, the three pieces of information will be referred to as adjustment reference information) as the deceleration pattern DP serving as the above-described reference. In this embodiment, the deceleration pattern is adjusted in accordance with all of the three pieces of adjustment reference information described above. The characteristic of the hybrid vehicle 1 is a characteristic, such as traveling resistance, engine brake working, or the like, of the hybrid vehicle 1 at deceleration. The surrounding environment of the hybrid vehicle 1 during traveling includes an inter-vehicle distance between the hybrid vehicle 1 and a preceding vehicle, whether forward visibility of the hybrid vehicle 1 is good or bad, a quantity of vehicles present around the hybrid vehicle 1 (congestion information), a road network and an arrangement of traffic lights around the hybrid vehicle 1, topography, weather, or the like. The inter-vehicle distance and the forward visibility are acquired from an image captured by a forward image capturing camera provided in the hybrid vehicle 1. The quantity of vehicles present around the hybrid vehicle 1 is acquired from a Vehicle Information and Communication System (VICS) (VICS is a registered trademark) or the like. The driver who is driving the hybrid vehicle 1 is identified by an image captured by a driver imaging camera provided in the hybrid vehicle 1, an input to the setting portion 21 by the driver himself / herself, or the like. When a plurality of deceleration patterns that serve as a reference (deceleration patterns to be multiplied by a specific value as appropriate in accordance with the vehicle speed and the deceleration of the hybrid vehicle 1) are stored, the setting portion 21 adjusts the deceleration pattern by selecting a deceleration pattern in accordance with the above-described adjustment reference information. On the other hand, when the deceleration pattern serving as a reference is independently stored, the setting portion 21 adjusts the deceleration pattern in accordance with the adjustment reference information described above (for example, multiplies the value of the deceleration at each vehicle speed by a value set for each vehicle speed based on the adjustment reference information). When a plurality of reference deceleration patterns that serve as a reference are stored, after a deceleration pattern is selected based on a part of the above-described adjustment reference information, the deceleration pattern may be further adjusted in accordance with the adjustment reference information whose deceleration pattern was not used as a reference for selecting the deceleration pattern.

[0036] In a case where, when the hybrid vehicle 1 is decelerated, the allowable upper limit of the EG torque is larger than the requested torque (between the timing t5 and the timing t7 in Fig. 2), the setting portion 21 estimates the vehicle stop transition period s with reference to the deceleration pattern illustrated in Fig. 4 (see Fig. 5). Then, as described above, after calculating the charging torque using the vehicle stop transition period s, the setting portion 21 sets the EG torque to which the charging torque is added, and sets the negative MG torque corresponding to the charging torque. The charging torque is calculated by dividing the subtracted charge amount ΔSoC (see (C) of Fig.2) by the vehicle stop transition period f and the rotation speed of the motor generator 17, as described above.

[0037] Next, calculation of the regenerative charge amount P used for calculating the subtracted charge amount ΔSoC will be described with reference to Figs. 6 and 7. Fig. 6 is an explanatory graph illustrating the regenerative charge amount P regenerated before the hybrid vehicle 1 is decelerated at a constant deceleration to be stopped. An ordinate in Fig. 6 represents the regenerative charge amount P and an abscissa in Fig. 6 represents the vehicle speed of the hybrid vehicle 1. Each value on the ordinate in Fig. 6 is a value normalized with setting the regenerative charge amount P assumed to be 1.0 when the hybrid vehicle 1 traveling at a vehicle speed of 120 km / h is decelerated at a constant deceleration to be stopped. As illustrated in Fig. 6, the larger the value of the vehicle speed is, the larger the regenerative charge amount P becomes.

[0038] Fig. 7 is an explanatory graph illustrating that, when the hybrid vehicle 1 is decelerated, the regenerative charge amount P varies in accordance with the value of the deceleration. An ordinate in Fig. 7 represents the regenerative charge amount P and an abscissa in Fig. 7 represents the deceleration. Each value on the ordinate in Fig. 7 is a value normalized with the regenerative charge amount P when the hybrid vehicle 1 is decelerated at the deceleration OD assumed to be 1.0. As illustrated in Fig. 7, in the hybrid vehicle 1, when the hybrid vehicle 1 is decelerated at the deceleration OD, the regenerative charge amount P is maximized, and when the hybrid vehicle 1 is decelerated at a deceleration smaller than the deceleration OD or a deceleration larger than the deceleration OD, the regenerative charge amount P is smaller than that when the hybrid vehicle 1 is decelerated at the deceleration OD.

[0039] In Fig. 7, it is indicated that, since the regenerative charge amount P is 0 at a deceleration equal to or less than a deceleration mD, the deceleration when the driver makes the stepping amount of the accelerator pedal 0 and causes the hybrid vehicle 1 to perform inertial traveling is the deceleration mD. The deceleration mD is caused by a friction loss of a power train and the traveling resistance of the hybrid vehicle 1. On the other hand, it is indicated that, when the deceleration is larger than the deceleration OD, a torque necessary for deceleration exceeds a torque (charging torque) that can be regenerated by the motor generator 17, so that a mechanical friction brake operates and the regenerative charge amount P decreases. In the above-described manner, even when the hybrid vehicle 1 is decelerated from the same vehicle speed, the regenerative charge amount P varies in accordance with the value of the deceleration. For example, in the period from the timing t1 to the timing t5 in Fig. 2, since the deceleration is smaller than the deceleration mD (the hybrid vehicle 1 is not decelerated), the regenerative charge amount P is 0. On the other hand, when deceleration is started at the timing t5, the deceleration becomes larger than the deceleration mD, and the regenerative charge amount P starts having a value. While the hybrid vehicle 1 is decelerated, with reference to the vehicle speed and the deceleration of the hybrid vehicle 1 included in the travel information collected by the information collecting portion 27, the setting portion 21 calculates, assuming that the hybrid vehicle 1 is decelerated while keeping the deceleration, the regenerative charge amount P using a map or a mathematical expression with the value of the vehicle speed (Fig. 6) and a value of the deceleration (Fig. 7) as inputs and the regenerative charge amount P as an output. The map or the mathematical expression is expressed in a form of, for example, the regenerative charge amount P = the vehicle speed influence × a deceleration influence. Weighting on each of the value of the vehicle speed and the value of the deceleration in the map or the mathematical expression may be arbitrarily set.

[0040] Fig. 8 is a flowchart illustrating steps of torque setting processing. The torque setting processing is periodically executed while the hybrid vehicle 1 is traveling. When the torque setting processing is started, the setting portion 21 first determines whether the requested torque requested by the hybrid vehicle 1 is larger than the allowable upper limit of the EG torque (Step S11).

[0041] When the requested torque is larger than the allowable upper limit of the EG torque (Step S11: YES), the setting portion 21 sets the EG torque equal to or smaller than the allowable upper limit, and then, sets a difference between the EG torque and the requested torque as the MG torque (Step S13). In other words, the setting portion 21 sets the EG torque to a value equal to or less than the allowable upper limit and sets the MG torque such that a sum of the EG torque and the MG torque is equal to the requested torque. After setting each of the EG torque and the MG torque (Step S13), the setting portion 21 terminates the torque setting processing.

[0042] On the other hand, when the allowable upper limit of the EG torque is larger than the requested torque (Step S11: NO), the setting portion 21 determines whether the hybrid vehicle 1 is decelerated (Step S15). Specifically, with reference to the travel information periodically collected by the information collecting portion 27, the setting portion 21 determines whether the hybrid vehicle 1 is decelerated, based on the acceleration of the hybrid vehicle 1 indicated by the travel information. In this embodiment, when the acceleration indicated by the travel information is a negative acceleration (deceleration), the hybrid vehicle 1 is considered to be decelerated. When the hybrid vehicle 1 is not decelerated (Step S15: NO), the setting portion 21 terminates the torque setting processing.

[0043] On the other hand, when the hybrid vehicle 1 is decelerated (Step S15: YES), setting portion 21 calculates the charging torque with reference to the deceleration pattern (Fig. 4) (Step S17). Specifically, the setting portion 21 estimates the vehicle stop transition period s (Fig. 5) with reference to the deceleration pattern (Fig. 4), and calculates the charging torque by dividing the subtracted charge amount ΔSoC (Fig. 2) by the estimated vehicle stop transition period f and the rotation speed of the motor generator 17. Note that the rotation speed of the motor generator 17 can be referred to from the travel information periodically collected by the information collecting portion 27.

[0044] After the charging torque is calculated (Step S17), the setting portion 21 sets the EG torque to which the charging torque is added, and sets the negative MG torque corresponding to the charging torque (step S19). Thereafter, the setting portion 21 terminates the torque setting processing.

[0045] Fig. 9 is explanatory graphs illustrating change of the vehicle speed of the hybrid vehicle 1 and the current charge amount CC of the secondary battery 18 with time when the hybrid vehicle 1 is caused to travel in a worldwide harmonized light duty driving test cycle (WLTC) mode on a vehicle simulation program. An ordinate in (A) of Fig. 9 represents the vehicle speed of the hybrid vehicle 1 and an ordinate in (B) of Fig. 9 represents the current charge amount CC of the secondary battery 18. Abscissas in (A) and (B) of Figs. 9 represent time. That is, the hybrid vehicle 1 starts traveling at a left end of the abscissa, and the hybrid vehicle 1 terminates traveling (ignition is turned off) at a right end of the abscissa. (B) of Fig. 9 illustrates a target charge amount ST.

[0046] As illustrated in (A) of Fig. 9, the hybrid vehicle 1 terminates traveling after stopping a plurality of times and, as illustrated in (B) of Fig. 9, charging of the secondary battery 18 is performed each time deceleration for stopping the hybrid vehicle 1 is started. Since the hybrid vehicle 1 is traveling in an order of an urban area, a suburban area, and an expressway, as illustrated in (A) of Fig. 9, the vehicle speed tends to increase as proceeding toward right along the abscissa (as time elapses). Along with that, as illustrated in (B) of Fig. 9, an extent of decrease in the current charge amount CC increases, and an extent of increase of the current charge amount CC due to charging during deceleration (charging in the period from the timing t5 to the timing t7 illustrated in (C) of Fig. 2) also increases.

[0047] In evaluation based on traveling in the WLTC mode described with reference to Fig. 9, a fuel efficiency improvement rate was 19.1% and a reduction rate of nitrogen oxides (NOx) in an exhaust gas was 32.6% in the hybrid vehicle 1, in contrast to a vehicle of a comparative example that does not include the secondary battery 18 and has only the engine as the drive source. The exhaust gas that was a target to be evaluated at this time was an exhaust gas before passing through an exhaust purification catalyst. Since a ratio of the current charge amount CC of the hybrid vehicle 1 after traveling in the WLTC mode to that before traveling in the WLTC mode was 101.8%, it was shown that an exhaust gas reduction effect can be continuously exhibited by an assist of the EG torque by the MG torque (torque assist) in the hybrid vehicle 1.

[0048] According to the hybrid vehicle 1 including the control device 20 of the first embodiment described above, the EG torque to which the charging torque is added is set during deceleration and the negative MG torque corresponding to the charging torque is set, so that the secondary battery 18 can be charged during deceleration of the hybrid vehicle 1. Moreover, the vehicle stop transition period f is estimated with reference to the deceleration pattern, so that accuracy of estimation of the vehicle stop transition period f can be increased. Furthermore, the charging torque is calculated using the vehicle stop transition period f, so that it is possible to prevent the charge amount of the secondary battery 18 from becoming too much or too little when the hybrid vehicle 1 is stopped. As a result, the torque assist by the motor generator 17 at acceleration (the assist by the MG torque when the requested torque is larger than the allowable upper limit of the EG torque) is ensured, so that it is possible to continuously achieve the fuel efficiency improvement effect and the exhaust gas reduction effect by the torque assist. It is also possible to avoid consumption of extra fuel due to a decrease in charge and discharge efficiency of the secondary battery 18 that occurs when the current charge amount CC is excessive.

[0049] Moreover, in the hybrid vehicle 1 including the control device 20 of the first embodiment, the setting portion 21 calculates the charging torque using the subtracted charge amount ΔSoC (the charge amount obtained by subtracting the regenerative charge amount P and the current charge amount CC from the target charge amount ST) and the vehicle stop transition period f. Thus, the charging torque is calculated using the subtracted charge amount ΔSoC in consideration of the regenerative charge amount P, so that it is possible to prevent the current charge amount CC of the secondary battery 18 from becoming excessive when the hybrid vehicle 1 is stopped. As a result, it is possible to further avoid consumption of extra fuel due to a decrease in the charge and discharge efficiency of the secondary battery 18 that occurs when the current charge amount CC is excessive.

[0050] In the hybrid vehicle 1 including the control device 20 of the first embodiment, the setting portion 21 can refer to the deceleration pattern adjusted in accordance with the adjustment reference information (the characteristic of the hybrid vehicle 1, the surrounding environment of the hybrid vehicle 1 during traveling, and the driver who is driving the hybrid vehicle 1). Thus, the deceleration pattern adjusted in accordance with a situation can be referred to, so that it is possible to further increase the accuracy of estimation of the vehicle stop transition period f. Therefore, accuracy of calculation of the charging torque is also increased, so that it is possible to further prevent the current charge amount CC of the secondary battery 18 from becoming too much or too little when the hybrid vehicle 1 is stopped.

[0051] Fig. 10 is a flowchart illustrating steps of torque setting processing that is performed in a hybrid vehicle including a control device according to a second embodiment. In the torque setting processing (Fig. 10) that is performed in the second embodiment, processes of Steps S16, S21, and 23 are further added to the torque setting processing (Fig. 8) described in the first embodiment. In description of Fig. 10, description of Steps S11, S13, S15, S17, and S19 that are same as those in Fig. 8 will be omitted.

[0052] In the second embodiment, when the hybrid vehicle is decelerated (Step S15: YES), the setting portion 21 determines whether the hybrid vehicle is decelerated at a deceleration smaller than a reference deceleration set as a reference in advance (Step S16). The reference deceleration is a deceleration that is regarded as a minimum. When the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration is, for example, when, assuming that the reference deceleration is a deceleration mD (in Fig. 7), the hybrid vehicle is decelerated at a deceleration having a value on left of the deceleration mD on the abscissa in Fig. 7. When the hybrid vehicle is not decelerated at a deceleration smaller than the reference deceleration (Step S16: NO), that is, when the hybrid vehicle is decelerated at a deceleration larger than the reference deceleration, similar to the first embodiment, the setting portion 21 executes processes of Steps S17 and S19.

[0053] On the other hand, when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES), or when the hybrid vehicle is not decelerated (Step S15: NO), the setting portion 21 calculates the charging torque with reference to a lower limit deceleration pattern (Step S21). The lower limit deceleration pattern is a deceleration pattern obtained by multiplying the deceleration pattern DP that serves as a reference by a lower limit magnification set in advance. In this embodiment, the lower limit magnification is 0.1, but an arbitrary value smaller than 1 is set therefor. In step S21, the setting portion 21 estimates the vehicle stop transition period s with reference to the lower limit deceleration pattern, and calculates the charging torque by dividing the subtracted charge amount ΔSoC (Fig. 2) by the estimated vehicle stop transition period f and the rotation speed of the motor generator 17. In this embodiment, since the lower limit magnification is 0.1, the vehicle stop transition period s is estimated by applying the vehicle speed of the hybrid vehicle 1 to the curved line CVa illustrated in Fig. 5.

[0054] After calculating the charging torque with reference to the lower limit deceleration pattern (Step S21), the setting portion 21 sets the EG torque to which the charging torque is added, and sets the negative MG torque corresponding to the charging torque (Step S23). Thereafter, the setting portion 21 terminates the torque setting processing.

[0055] One of triggers for executing Step S21 and Step S23 is that the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES). Even when the hybrid vehicle is decelerated, in a case where the deceleration is minimal, in accordance with the method for estimating the vehicle stop transition period f described in Fig. 3, the vehicle stop transition period f estimated by setting an extension line along an inclination at a time of the deceleration is prolonged (as described in Fig. 5, the vehicle stop transition period f is similarly prolonged also when the vehicle stop transition period f is estimated using the deceleration pattern of Fig. 4). In addition, since the charging torque calculated by using the vehicle stop transition period f prolonged as described above becomes small, there is a concern that the charging efficiency is significantly decreased. In this embodiment, in consideration of the above-described point, when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES), the charging torque is calculated with reference to the lower limit deceleration pattern (Step S21). Thus, it is possible to prevent the charging efficiency of the motor generator 17 when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration from being significantly reduced.

[0056] Another trigger for executing Step S21 and Step S23 is that the hybrid vehicle is not decelerated (Step S15: NO). In the torque setting processing executed while the hybrid vehicle 1 is traveling, a time when the hybrid vehicle is not decelerated is a time when the hybrid vehicle is accelerated or travels at a constant speed. At this time, according to the method of estimating the vehicle stop transition period f described with reference to Fig. 3, the vehicle stop transition period f cannot be estimated (becomes infinite) even when the extension lines (illustrated as the extension lines La and Lb) along the inclination at the traveling time point are set. In this regard, in this embodiment, even when the hybrid vehicle is not decelerated (when the hybrid vehicle is accelerated or travels at a constant speed), the charging torque is calculated with reference to the lower limit deceleration pattern (Step S21) on a premise that the allowable upper limit of the EG torque is larger than the requested torque (Step S11: NO). Thus, even when the hybrid vehicle is accelerated or travels at a constant speed, the secondary battery 18 can be charged by setting the negative MG torque in accordance with the charging torque.

[0057] Also in the second embodiment described above, similar to the first embodiment, by ensuring the torque assist by the motor generator 17 at acceleration, it is possible to continuously achieve the fuel efficiency improvement effect and the exhaust gas reduction effect by the torque assist.

[0058] In the second embodiment, when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES), the charging torque is calculated using the vehicle stop transition period f estimated with reference to the lower limit deceleration pattern, so that the secondary battery 18 can be more efficiently charged than when the deceleration pattern based on a deceleration smaller than the reference deceleration (the deceleration pattern adjusted by multiplying the deceleration pattern serving as a reference by a specific value so that the deceleration pattern matches a deceleration smaller than the reference deceleration, see Fig. 4) is referred to.

[0059] Moreover, in the second embodiment, even when the hybrid vehicle is accelerated or travels at a constant speed, the charging torque is calculated using the vehicle stop transition period f estimated with reference to the lower limit deceleration pattern, so that, even when the hybrid vehicle is accelerated or travels at a constant speed, the secondary battery 18 can be charged. Therefore, even when the hybrid vehicle is decelerated at a low frequency, it is possible to prevent the charge amount of the secondary battery 18 from becoming insufficient.

[0060] <Variations of Examples> The present invention is not limited to the embodiments described above and can be carried out in various embodiments without departing from the spirit thereof and, for example, the following variations are also possible. ・The adjustment may not be performed in accordance with all the adjustment reference information.First Variation

[0061] Although, in the above-described embodiments, the control device 20 includes the EG drive control portion 23 and the MG drive control portion 25, the control device 20 is not limited thereto. The control device 20 may not include the EG drive control portion 23 and the MG drive control portion 25. In such a case, the EG drive control portion 23 and the MG drive control portion 25 provided outside the control device 20 receive the EG torque and the MG torque set by the setting portion 21, and then, drive the engine 11 and the motor generator 17 in accordance with the EG torque and the MG torque in the hybrid vehicle 1.Second Variation

[0062] Although, in the above-described embodiments, the secondary battery 18 is used as the power storage portion, the power storage portion is not limited thereto. For example, the power storage portion may be a capacitor.Third Variation

[0063] Although, in the above-described embodiments, the deceleration pattern can be adjusted in accordance with all of the three pieces of adjustment reference information, adjustment of the deceleration pattern is not limited thereto. For example, the deceleration pattern may be adjustable in accordance with at least one of the three pieces of adjustment reference information.Fourth Variation

[0064] Although, in the second embodiment, either when the hybrid vehicle is not decelerated (Step S15: NO) or when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES), the charging torque is calculated with reference to the lower limit deceleration pattern (Step S21), calculation of the charging torque is not limited thereto. For example, the charging torque may not be calculated (Step S21) when the hybrid vehicle is not decelerated (Step S15: NO), and the charging torque may be calculated (Step S21) only when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES). Similarly, the charging torque may be calculated (Step S21) only when the hybrid vehicle is not decelerated (Step S15: NO), and the charging torque may not be calculated (Step S21) when the hybrid vehicle is decelerated at a deceleration smaller than the reference deceleration (Step S16: YES).Fifth Variation

[0065] Although, in the second embodiment, the lower limit deceleration pattern is a deceleration pattern obtained by multiplying the deceleration pattern DP serving as a reference by the lower limit magnification set in advance, the lower limit deceleration pattern is not limited thereto. For example, the lower limit deceleration pattern may be created in advance without multiplying the deceleration pattern DP by the lower limit magnification.

[0066] Aspects of the present invention have been described above based on the embodiments and the variations, the embodiments of the aspects described above are intended to facilitate understanding of the aspects of the present invention and do not limit the aspects of the present invention. The aspects of the present invention may be changed and improved without departing from the gist and the scope of the claims, and the aspects of the present invention include equivalents thereof. In addition, if the technical features are not described as essential in the present specification, the technical features can be appropriately deleted.

[0067] The present invention can also be implemented in the following aspects.First Application Example

[0068] A control device for a hybrid vehicle including an engine and a motor generator that are driving sources and a power storage portion that supplies electric power to the motor generator and stores electric power generated by the motor generator, the control device including: a setting portion that sets an engine torque that is output from the engine and a motor generator torque that is output from the motor generator in accordance with a requested torque requested by the hybrid vehicle; and an information collecting portion that collects travel information including at least current vehicle speed and acceleration of the hybrid vehicle, in which, in a case where, when the hybrid vehicle is decelerated, an allowable upper limit of the engine torque that is allowed to be output is larger than the requested torque, after estimating, with reference to a deceleration pattern in which change of a deceleration with time until the hybrid vehicle traveling at the vehicle speed and the deceleration that is a negative acceleration, the vehicle speed and the deceleration being indicated by the travel information, is stopped is estimated, a vehicle stop transition period until the hybrid vehicle is stopped and calculating a charging torque used for charging the power storage portion using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets a negative motor generator torque corresponding to the charging torque.Second Application Example

[0069] The control device for a hybrid vehicle described in the first application example, in which, in a case where, when the hybrid vehicle is decelerated at the deceleration smaller than a reference deceleration set as a reference in advance, the allowable upper limit of the engine torque is larger than the requested torque, after estimating the vehicle stop transition period with reference to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit magnification set in advance and calculating the charging torque using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets the negative motor generator torque corresponding to the charging torque.Third Application Example

[0070] The control device for a hybrid vehicle described in the first or second application example, in which, in a case where, when the hybrid vehicle is accelerated or travels at a constant speed, the allowable upper limit of the engine torque is larger than the requested torque, after estimating the vehicle stop transition period with reference to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit magnification set in advance and calculating the charging torque using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets the negative motor generator torque corresponding to the charging torque.Fourth Application Example

[0071] The control device for a hybrid vehicle described in any one of the first to third application example, in which the setting portion calculates the charging torque using a subtracted charge amount obtained by subtracting a current charge amount of the power storage portion and a regenerative charge amount that can be regenerated before the hybrid vehicle is stopped from a target charge amount that is a target of the charge amount of the power storage portion and the vehicle stop transition period.Fifth Application Example

[0072] The control device for a hybrid vehicle described in any one of the first to fourth application examples, in which the setting portion is able to refer to the deceleration pattern adjusted in accordance with at least one of a characteristic of the hybrid vehicle, a surrounding environment of the hybrid vehicle during traveling, and a driver who is driving the hybrid vehicle.

[0073] 1 HYBRID VEHICLE 11 ENGINE 12 TRANSMISSION 13 PROPELLER SHAFT 14 DIFFERENTIAL GEAR 15 DRIVE SHAFT 16 TIRE 17 MOTOR GENERATOR 18 SECONDARY BATTERY 20 CONTROL DEVICE 21 SETTING PORTION 23 EG DRIVE CONTROL PORTION 25 MG DRIVE CONTROL PORTION 27 INFORMATION COLLECTING PORTION

Claims

1. A control device for a hybrid vehicle including an engine and a motor generator that are driving sources and a power storage portion that supplies electric power to the motor generator and stores electric power generated by the motor generator, the control device comprising: a setting portion that sets an engine torque that is output from the engine and a motor generator torque that is output from the motor generator in accordance with a requested torque requested by the hybrid vehicle; and an information collecting portion that collects travel information including at least current vehicle speed and acceleration of the hybrid vehicle, wherein, in a case where, when the hybrid vehicle is decelerated, an allowable upper limit of the engine torque that is allowed to be output is larger than the requested torque, after estimating, with reference to a deceleration pattern in which change of a deceleration with time until the hybrid vehicle traveling at the vehicle speed and the deceleration that is a negative acceleration, the vehicle speed and the deceleration being indicated by the travel information, is stopped is estimated, a vehicle stop transition period until the hybrid vehicle is stopped and calculating a charging torque used for charging the power storage portion using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets a negative motor generator torque corresponding to the charging torque.

2. The control device for a hybrid vehicle according to claim 1, wherein, in a case where, when the hybrid vehicle is decelerated at the deceleration smaller than a reference deceleration set as a reference in advance, the allowable upper limit of the engine torque is larger than the requested torque, after estimating the vehicle stop transition period with reference to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit magnification set in advance and calculating the charging torque using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets the negative motor generator torque corresponding to the charging torque.

3. The control device for a hybrid vehicle according to claim 1, wherein, in a case where, when the hybrid vehicle is accelerated or travels at a constant speed, the allowable upper limit of the engine torque is larger than the requested torque, after estimating the vehicle stop transition period with reference to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit magnification set in advance and calculating the charging torque using the vehicle stop transition period, the setting portion sets the engine torque to which the charging torque is added and sets the negative motor generator torque corresponding to the charging torque.

4. The control device for a hybrid vehicle according to claim 1, wherein the setting portion calculates the charging torque using a subtracted charge amount obtained by subtracting a current charge amount of the power storage portion and a regenerative charge amount that can be regenerated before the hybrid vehicle is stopped from a target charge amount that is a target of a charge amount of the power storage portion and the vehicle stop transition period.

5. The control device for a hybrid vehicle according to any one of claims 1 to 4, wherein the setting portion is able to refer to the deceleration pattern adjusted in accordance with at least one of a characteristic of the hybrid vehicle, a surrounding environment of the hybrid vehicle during traveling, and a driver who is driving the hybrid vehicle.

Images