Control device of hybrid vehicle

Abstract

To provide a technology capable of improving estimation accuracy of a stop transition period in a control device of a hybrid vehicle.SOLUTION: A control device of a hybrid vehicle includes a setting part for setting engine torque and motor generator torque in accordance with request torque, and an information collection part for collecting travel information including a current vehicle speed and acceleration of the hybrid vehicle. The setting part estimates a stop transition period with reference to a deceleration pattern obtained by estimating a change in deceleration over time till reaching a stop of the hybrid vehicle traveling at a vehicle speed and at a deceleration being a negative acceleration shown by the travel information if an allowable upper limit of the engine torque that allows an output is greater than the request torque when the hybrid vehicle decelerates, sets the engine torque obtained by adding charging torque calculated by using the stop transition period and sets negative motor generation torque corresponding to the charging torque.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, hybrid vehicles are known that are equipped with an engine and a motor generator as drive sources, and an electricity storage unit that exchanges electric power with the motor generator. In such hybrid vehicles, motor generator torque may be output in addition to engine torque in order to meet the torque requirement required during acceleration. Patent Document 1 discloses a control device that controls a generator motor that corresponds to the motor generator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-123509 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to suppress a shortage of the charge amount of the electric storage unit, for example, when the allowable upper limit of the engine torque that allows the output of the hybrid vehicle during deceleration is larger than the required torque, it is possible to set the engine torque with the charging torque for charging the electric storage unit added thereto, thereby charging the electric storage unit while decelerating the hybrid vehicle. In this case, the charging torque should be set according to the stop transition period until the hybrid vehicle stops, so that the electric storage unit is charged without excess or deficiency when the hybrid vehicle stops. However, it is difficult to estimate this stop transition period, and if the charging torque is set according to the stop transition period estimated with low accuracy, the electric storage unit cannot be sufficiently charged and the torque assist by the motor generator cannot be secured, so that the fuel efficiency improvement effect and the exhaust gas reduction effect by the torque assist cannot be continuously obtained. Therefore, a technology that can improve the estimation accuracy of the stop transition period has been desired. Note that Patent Document 1 does not take into consideration setting the engine torque with the charging torque added thereto in a hybrid vehicle during deceleration.

[0005] The present invention has been made to solve at least part of the above-mentioned problems, and aims to provide a technology that can improve the estimation accuracy of the stop transition period in a control device for a hybrid vehicle. [Means for solving the problem]

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0007] (1) According to one aspect of the present invention, there is provided a control device for a hybrid vehicle, the control device including an engine and a motor generator as drive sources, and an electricity storage unit that supplies electric power to the motor generator and stores the electric power generated by the motor generator, the control device including: a setting unit that sets an engine torque output from the engine and a motor generator torque output from the motor generator according to a required torque required for the hybrid vehicle, and an information collection unit that collects travel information including at least a current vehicle speed and acceleration of the hybrid vehicle, and when an allowable upper limit of the engine torque that is allowed to be output is greater than the required torque while the hybrid vehicle is decelerating, the setting unit estimates a stop transition period until the hybrid vehicle stops by referring to the vehicle speed indicated by the travel information and a deceleration pattern that estimates a change over time in the deceleration of the hybrid vehicle traveling at a deceleration that is a negative acceleration, and calculates a charging torque for charging the electricity storage unit using the stop transition period, and then sets the engine torque with the charging torque added thereto, and sets a negative motor generator torque according to the charging torque.

[0008] According to this configuration, the engine torque with the charging torque added thereto is set during deceleration of the hybrid vehicle, and a negative motor generator torque corresponding to the charging torque is set, so that the power storage unit can be charged during deceleration of the hybrid vehicle. In addition, the stop transition period is estimated by referring to the deceleration pattern, so that the estimation accuracy of the stop transition period can be improved. Furthermore, the charging torque is calculated using the stop transition period, so that it is possible to prevent the charge amount of the power storage unit from being excessive or insufficient when the hybrid vehicle is stopped. As a result, the torque assist by the motor generator during acceleration is ensured, so that the effect of improving fuel efficiency and the effect of reducing exhaust gas due to the torque assist can be continuously obtained. In addition, it is also possible to avoid excess fuel consumption due to a decrease in the charge / discharge efficiency of the power storage unit that occurs when the charge amount becomes excessive.

[0009] (2) In the control device of the above embodiment, when the hybrid vehicle is decelerating at a deceleration rate that is smaller than a reference deceleration rate that is preset as a standard, and the allowable upper limit of the engine torque is greater than the required torque, the setting unit may estimate the stop transition period by referring to a lower limit deceleration pattern that is obtained by multiplying the deceleration pattern by a lower limit multiplier that is preset, calculate the charging torque using the stop transition period, set the engine torque plus the charging torque, and set a negative motor generator torque corresponding to the charging torque. According to this configuration, when the hybrid vehicle decelerates at a deceleration rate smaller than the reference deceleration rate, the charging torque is calculated using the stop transition period estimated by referring to the lower limit deceleration pattern, so that the secondary battery can be charged more efficiently than when a deceleration pattern based on a deceleration rate smaller than the reference deceleration rate is referred to.

[0010] (3) In the control device of the above embodiment, when the hybrid vehicle is accelerating or traveling at a constant speed and the allowable upper limit of the engine torque is greater than the required torque, the setting unit may estimate the stop transition period by referring to a lower limit deceleration pattern multiplied by a preset lower limit multiplier to the deceleration pattern, calculate the charging torque using the stop transition period, set the engine torque plus the charging torque, and set a negative motor generator torque corresponding to the charging torque. According to this configuration, even when the hybrid vehicle is accelerating or running at a constant speed, the charging torque is calculated using the stop transition period estimated by referring to the lower limit deceleration pattern, so that the power storage unit can be charged even when the hybrid vehicle is accelerating or running at a constant speed. Therefore, even when the hybrid vehicle is not decelerated frequently, it is possible to prevent the charge amount of the power storage unit from becoming insufficient.

[0011] (4) In the control device of the above embodiment, the setting unit may calculate the charging torque using a subtraction charge amount obtained by subtracting a current charge amount of the power storage unit and a regenerative charge amount that can be regenerated before the hybrid vehicle comes to a stop from a target charge amount that is a target for the charge amount of the power storage unit, and the stop transition period. According to this configuration, since the charging torque is calculated using the subtracted charge amount that takes into account the regenerative charge amount, it is possible to prevent the charge amount of the power storage unit from becoming excessive when the hybrid vehicle is stopped. As a result, it is possible to further prevent excess fuel consumption due to a decrease in the charge / discharge efficiency of the power storage unit that occurs when the charge amount becomes excessive.

[0012] (5) In the control device of the above embodiment, the setting unit may be capable of referring to the deceleration pattern adjusted according to at least one of characteristics of the hybrid vehicle, an environment surrounding the hybrid vehicle while traveling, and a driver driving the hybrid vehicle. According to this configuration, since it is possible to refer to the deceleration pattern adjusted according to the situation, it is possible to further improve the estimation accuracy of the stop transition period. Therefore, since the calculation accuracy of the charging torque is also improved, it is possible to further prevent the charge amount of the power storage unit from being overcharged or undercharged when the hybrid vehicle is stopped.

[0013] The present invention can be realized in various forms, for example, in the form of a hybrid vehicle equipped with the control device, a control method for a hybrid vehicle, and the like. [Brief description of the drawings]

[0014] [Figure 1] 1 is an explanatory diagram illustrating a hybrid vehicle equipped with a control device of a first embodiment. [Diagram 2] FIG. 4 is an explanatory diagram showing changes over time in vehicle speed, EG torque, and current charge amount. [Diagram 3] FIG. 4 is an explanatory diagram showing a speed change of a hybrid vehicle until the vehicle comes to a stop. [Figure 4]FIG. 4 is an explanatory diagram of a deceleration pattern used when estimating a stop transition period. [Diagram 5] FIG. 11 is an explanatory diagram showing a stop transition period when decelerating according to each deceleration pattern. [Figure 6] FIG. 4 is an explanatory diagram showing the amount of regenerative charge regenerated when decelerating at a constant deceleration rate. [Figure 7] FIG. 11 is an explanatory diagram showing that the regenerative charge amount varies depending on the value of the deceleration rate. [Figure 8] 5 is a flowchart showing a procedure of a torque setting process according to the first embodiment. [Figure 9] FIG. 4 is an explanatory diagram showing changes over time in vehicle speed and current charge amount. [Figure 10] 10 is a flowchart showing a procedure of a torque setting process according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] First Embodiment 1 is an explanatory diagram illustrating the configuration of a hybrid vehicle 1 equipped with a control device 20 (described in detail later) according to a first embodiment. In addition to the control device 20, the hybrid vehicle 1 is equipped with 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, engine torque (hereinafter referred to as EG torque) output from the engine 11 is transmitted to the propeller shaft 13 as axle torque. During power running, motor generator torque (hereinafter referred to as MG torque) output from the motor generator 17 using electric power supplied from a secondary battery 18 is transmitted to the propeller shaft 13 as axle torque. The axle torque is transmitted to the tires 16 as drive torque via the differential gear 14 and the drive shaft 15. The engine 11 and the motor generator 17 serve as drive sources for the hybrid vehicle 1.

[0017] On the other hand, during regeneration, the axle torque is transmitted to the motor generator 17 as MG torque. This MG torque is used for power generation by the motor generator 17. The electric power generated by the motor generator 17 is charged to the secondary battery 18. In this way, the secondary battery 18 serves as a power storage unit, supplying electric power to the motor generator 17 during power running, and storing the electric power generated by the motor generator 17 during regeneration.

[0018] The control device 20 includes a setting unit 21, an EG drive control unit 23, an MG drive control unit 25, and an information collection unit 27. The setting unit 21 sets the EG torque output from the engine 11 and the MG torque output from the motor generator 17 according to the required torque required for the hybrid vehicle 1. Here, the required torque is calculated according to the depression amount of an accelerator pedal (not shown) and a brake pedal (not shown) of the hybrid vehicle 1. The EG drive control unit 23 drives the engine 11 according to the set EG torque. The MG drive control unit 25 drives the motor generator 17 according to the set MG torque. The information collection unit 27 collects travel information related to the hybrid vehicle 1 during travel. The information collection unit 27 periodically collects the travel information while the hybrid vehicle 1 is operating, and transmits a signal indicating the information to the setting unit 21. The travel information includes, for example, the current vehicle speed and acceleration of the hybrid vehicle 1, the current charge amount of the secondary battery 18, the rotation speed of the motor generator 17, and the like. The acceleration acquired from the driving information includes not only positive acceleration but also negative acceleration indicating deceleration.

[0019] FIG. 2 is an explanatory diagram showing the change over time of the vehicle speed, EG torque, and the current charge amount CC of the secondary battery 18 of the hybrid vehicle 1. FIG. 2(A) shows the change over time of the vehicle speed of the hybrid vehicle 1. The vertical axis of FIG. 2(A) shows the vehicle speed of the hybrid vehicle 1, and the horizontal axis of FIG. 2(A) shows time. The horizontal axes of FIG. 2(B) and (C) described below also show time. FIG. 2(B) shows the change over time of the EG torque output by the engine 11. The vertical axis of FIG. 2(B) shows the EG torque output by the engine 11. The solid line b1 of FIG. 2(B) shows the EG torque that changes over time, and the dashed line b2 shows the required torque that changes over time. FIG. 2(C) shows the change over time of the current charge amount CC of the secondary battery 18. The vertical axis of FIG. 2(C) shows the current charge amount CC of the secondary battery 18. The solid line c1 in Fig. 2(C) indicates the current charge amount CC of the secondary battery 18, which changes over time. The dashed line c2 in Fig. 2(C) indicates the target charge amount ST, which is the target charge amount of the secondary battery 18. The target charge amount ST is preferably set so that a charge amount remains even after accelerating to the maximum speed with the accelerator pedal depressed to 100%, for example. The dashed dotted line c3 in Fig. 2(C) will be described later.

[0020] At time t1, when an acceleration request to accelerate to vehicle speed V (see FIG. 2(A)) is detected due to an increase in accelerator pedal depression, a required torque is calculated according to the depression amount. At this time, the information collecting unit 27 transmits a signal indicating information such as the intake air amount, intake pipe pressure, fuel injection amount, and rotation speed of the engine 11 as driving information to the setting unit 21. Based on this information, the setting unit 21 sets the EG torque below the upper limit of the allowable range (allowable upper limit) that satisfies the emission standards for exhaust gas from the engine 11. With this setting, the EG torque starts to increase from time t1, as shown by the solid line b1 in FIG. 2(B).

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

[0022] The EG torque between timing t1 and timing t3 is the allowable upper limit of the EG torque. As shown by the solid line b1 and the dashed line b2 in FIG. 2B, the allowable upper limit of the EG torque allowed to be output during this period is smaller than the required torque. In this case, the setting unit 21 sets an EG torque equal to or lower than the allowable upper limit, and sets the difference between this EG torque and the required torque as the MG torque. That is, between timing t1 and timing t3, the MG torque is set as a supplement to the EG torque set to be equal to or lower than the allowable upper limit. At this time, as shown by the solid line c1 in FIG. 2C, the charge amount of the secondary battery 18 during the period from timing t1 to timing t3 is reduced by the amount of the MG torque used to supplement the EG torque.

[0023] As the vehicle speed of the hybrid vehicle 1 approaches vehicle speed V (see FIG. 2(A)), the depression amount of the accelerator pedal starts to decrease from time t2, and the required torque also starts to decrease (see FIG. 2(B)). After that, at time t3, the decreasing required torque becomes equal to the EG torque that increases while maintaining the allowable upper limit (solid line b1 and dashed dotted line b2 intersect). At this time, the allowable upper limit of the EG torque transitions to a state where it is greater than the required torque.

[0024] Between timing t4 and timing t5, the vehicle speed of the hybrid vehicle 1 is maintained at vehicle speed V. That is, during this time, the hybrid vehicle 1 travels at a constant speed. When depression of the brake pedal begins from timing t5, the hybrid vehicle 1 begins to decelerate as the EG torque decreases. At this time, the required torque also begins to decrease and transitions to a negative required torque. Brake regeneration is performed while the required torque is negative. Also, at timing t6, the EG torque becomes 0. Then, at timing t7, the vehicle speed also becomes 0, and the hybrid vehicle 1 comes to a stop.

[0025] During the period from timing t5 to timing t7, when the hybrid vehicle 1 is decelerating, the allowable upper limit of the EG torque is greater than the required torque. When a deceleration request is detected at timing t5 due to an increase in the depression amount of the brake pedal, the setting unit 21 uses this as a trigger to set an EG torque that is an added amount of charging torque for charging the secondary battery 18 in order to perform deceleration regeneration in which the secondary battery 18 is charged while decelerating the hybrid vehicle 1. In other words, the EG torque that is set at this time is a torque that is a sum of the torque for driving the hybrid vehicle 1 and the charging torque. In addition, the setting unit 21 sets a negative MG torque according to the charging torque. The negative MG torque means an MG torque during regeneration in which power is generated to be stored in the secondary battery 18.

[0026] The charge torque is calculated using the net charge amount ΔSoC and the vehicle stop transition period f. The net charge amount ΔSoC is the charge amount obtained by subtracting the current charge amount CC of the secondary battery 18 (see solid line c1 in FIG. 2C) and the regenerative charge amount P that can be recovered by brake regeneration before the hybrid vehicle 1 comes to a stop from the target charge amount ST (see dashed line c2 in FIG. 2C), which is the target charge amount of the secondary battery 18. The dashed-dotted line c3 in FIG. 2C indicates the charge amount obtained by subtracting only the regenerative charge amount P from the target charge amount ST. In other words, the regenerative charge amount P begins to have a value after deceleration begins at timing t5. Therefore, between timing t1 and timing t5, the charge subtraction amount ΔSoC is a value obtained by subtracting only the current charge amount CC (solid line c1) of the secondary battery 18 from the target charge amount ST (dashed line c2) because the regenerative charge amount P does not have a value (shown as an arrow with arrowheads at both ends between the solid line c1 and dashed line c2). On the other hand, between timing t5 and timing t7, the charge subtraction amount ΔSoC is a value obtained by subtracting only the regenerative charge amount P from the target charge amount ST (dash-dotted line c3) and further subtracting the current charge amount CC (solid line c1) of the secondary battery 18 (shown as an arrow with arrowheads at both ends between the solid line c1 and dash-dotted line c3). As shown in FIG. 2C, after timing t6, the charge subtraction amount ΔSoC becomes 0, and charging is performed only by brake regeneration between timing t6 and timing t7. In other words, during the period from timing t6 to 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 dashed dotted line c3 coincide with each other). The calculation of the regenerative charge amount P will be described in detail later.

[0027] The stop transition period f used in the calculation of the charging torque in addition to the charge subtraction amount ΔSoC is the period until the hybrid vehicle 1 stops. The stop transition period f is estimated by the setting unit 21 by referring to the deceleration pattern described in FIG. 4, and will be described in detail later. The charging torque is calculated by dividing the charge subtraction amount ΔSoC by the 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 obtained from the traveling information successively collected by the information collecting unit 27. The rotation speed of the motor generator 17 used in the calculation of the charging torque may be the current rotation speed, may be the rotation speed at the next time calculated taking into account the current deceleration, or may be the average value of the current rotation speed and the rotation speed at the next time.

[0028] Between timing t5 and timing t7, the hybrid vehicle 1 decelerates while charging the secondary battery 18, and then at timing t7, the hybrid vehicle 1 comes to a stop and the required torque becomes 0. Note that, between timing t5 and timing t6, an EG torque that includes the charging torque is set, but if the EG torque is greater than the allowable upper limit, it is preferable to adjust the charging torque so that it is equal to or less than the allowable upper limit.

[0029] Next, the estimation of the stop transition period f will be described with reference to Figs. 3 to 5. Fig. 3 is an explanatory diagram showing the speed change of the hybrid vehicle 1 until the vehicle comes to a stop. Fig. 3(A) shows the change in vehicle speed over time. Fig. 3(B) shows the change in acceleration and deceleration (negative acceleration) over time. The vertical axis of Fig. 3(A) shows the vehicle speed of the hybrid vehicle 1, and the vertical axis of Fig. 3(B) shows the acceleration and deceleration of the hybrid vehicle 1. The horizontal axis of Figs. 3(A) and (B) shows time.

[0030] As shown in FIG. 3(A)(B), in period P1, the driver accelerates the hybrid vehicle 1 and reduces the accelerator pedal depression (acceleration) as the vehicle approaches a target vehicle speed. In period P2, the driver keeps the accelerator pedal depression constant (acceleration 0) to maintain a constant speed. In period P3, the driver senses a stop event (a red light or a preceding vehicle is stopped, etc.) and starts depressing the brake pedal (deceleration). In period P4, the driver adjusts the brake pedal depression (deceleration) toward the stopping position. In period P5, the driver gradually reduces the brake pedal depression (deceleration) to mitigate the impact when the vehicle stops, and the vehicle stops. As shown in FIG. 3(B), the deceleration after period P3 is not constant, and in the general market driving tendency, the deceleration is gradual at the start of deceleration (period P3), and the deceleration increases as the stopping position approaches (period P4), and adjustments are made to mitigate the impact when the vehicle stops just before stopping (period P5).

[0031] In FIG. 3(A), if it is assumed that the acceleration (deceleration) at each time point continues at a constant rate, it is possible to estimate the period from each time point until the hybrid vehicle 1 stops (i.e., the stop transition period f). For example, when an extension line Lc along the slope of the time point Tc is set and an intersection point Nc where the extension line Lc intersects with the time axis is set, the stop transition period f is estimated as the period from the time point Tc to the intersection point Nc. On the other hand, the extension lines La and Lb along the slope of the times Ta and Tb do not intersect with the time axis, so the stop transition period f cannot be estimated (becomes infinite). This means that when the hybrid vehicle 1 is accelerating or traveling at a constant speed, it is unclear when a stop event will occur, so the stop transition period f cannot be estimated, and it becomes possible to estimate the stop transition period f only when the hybrid vehicle 1 starts to decelerate. Furthermore, as the period progresses from P3 to periods P4 and P5, the length of the stop transition period f is estimated to be shorter (illustrated as multiple arrows with arrowheads at both ends between timing t5 and timing t7 in Figure 2(A)), and when the vehicle speed becomes 0, the stop transition period f is also estimated to be 0.

[0032] FIG. 4 is an explanatory diagram of the deceleration pattern DP used by the setting unit 21 when estimating the stop transition period f. The vertical axis of FIG. 4 indicates the deceleration of the hybrid vehicle 1, and the horizontal axis of FIG. 4 indicates the vehicle speed of the hybrid vehicle 1. The deceleration pattern DP is a pattern that estimates the change over time in the deceleration of the hybrid vehicle 1 traveling at the vehicle speed and deceleration indicated by the traveling information until the hybrid vehicle 1 stops. For example, when the vehicle speed and deceleration of the hybrid vehicle 1 are at point D on the deceleration pattern DP, the change over time in the deceleration of the hybrid vehicle 1 is estimated to follow the deceleration pattern DP. The deceleration pattern DP was created by running the vehicle in the market, collating a plurality of data in which each vehicle speed (in this embodiment, a vehicle speed every 15 km / h) corresponds to the deceleration at each vehicle speed, and defining the deceleration at each vehicle speed as the deceleration that is greater than 90% of the deceleration corresponding to each vehicle speed. The deceleration that is greater than 90% of the decelerations corresponding to each vehicle speed means, for example, that in the deceleration pattern DP, a deceleration of 2.75 km / s corresponds to a vehicle speed of 60 km / h, and this deceleration of 2.75 km / s is greater than the deceleration value indicated by 90% of the various deceleration values ​​corresponding to a vehicle speed of 60 km / h in data collected from market driving. The deceleration pattern DP shows a tendency that the deceleration is small when the vehicle speed is relatively high, and the deceleration is large when the vehicle speed is relatively low. The deceleration pattern DP may be stored in the setting unit 21, or may be stored in a separate device that can communicate with the setting unit 21. This separate device may be provided either inside or outside the hybrid vehicle 1.

[0033] The deceleration pattern DPc is a pattern in which the deceleration value at each vehicle speed in the deceleration pattern DP is multiplied by 0.6. For example, when the vehicle speed and deceleration of the hybrid vehicle 1 are at point Dc, point Dc is not on the deceleration pattern DP, so that the change over time in the deceleration of the hybrid vehicle 1 cannot be estimated using the deceleration pattern DP. For this reason, in this embodiment, the deceleration value at each vehicle speed in the deceleration pattern DP is multiplied by a specific value (0.6 in the deceleration pattern DPc) to create a deceleration pattern DPc that passes through point Dc. Of course, all of the deceleration values ​​at each vehicle speed are multiplied by the same specific value. By referring to the deceleration pattern DPc created in this way, the change over time in the deceleration of the hybrid vehicle 1 traveling at the vehicle speed and deceleration shown at point Dc can be estimated. In this manner, in this embodiment, the deceleration pattern DP is used as a reference, and a specific value is appropriately multiplied by the deceleration pattern DP depending on the vehicle speed and deceleration of the hybrid vehicle 1 to create a deceleration pattern (exemplified as deceleration pattern DPc in the above explanation) that is suited to the vehicle speed and deceleration, thereby making it possible to estimate the change over time in the deceleration of the hybrid vehicle 1 traveling at any vehicle speed and deceleration.

[0034] FIG. 5 is an explanatory diagram showing the stop transition period s of the hybrid vehicle 1 when decelerating according to each deceleration pattern. A curve CV shows the stop transition period s when decelerating according to the deceleration pattern DP. As shown by point D (corresponding to point D in FIG. 4), the stop transition period s when the hybrid vehicle 1 with a vehicle speed of 120 km / h decelerates according to the deceleration pattern DP is estimated to be about 49 seconds. Moreover, a curve CVc shows the stop transition period s when decelerating according to the deceleration pattern DPc (a pattern in which the deceleration value at each vehicle speed in the deceleration pattern DP is multiplied by 0.6). As shown by point Dc (corresponding to point Dc in FIG. 4), the stop transition period s when the hybrid vehicle 1 with a vehicle speed of 60 km / h decelerates according to the deceleration pattern DPc is estimated to be about 24 seconds. Each of the curves CVa, CVb, CVd, and CVe indicates a stop transition period s when decelerating according to a deceleration pattern (not shown) obtained by multiplying the deceleration value at each vehicle speed in the deceleration pattern DP by 0.1, 0.4, 0.8, and 1.2, respectively.

[0035] In this embodiment, the setting unit 21 can refer to the deceleration pattern adjusted according to at least one of the characteristics of the hybrid vehicle 1, the surrounding environment of the hybrid vehicle 1 during travel, and the driver who is driving the hybrid vehicle 1 (hereinafter, these three pieces of information are referred to as adjustment reference information) as the deceleration pattern DP that serves as the above-mentioned reference. In this embodiment, the deceleration pattern is adjusted according to all of the above-mentioned three pieces of adjustment reference information. The characteristics of the hybrid vehicle 1 refer to characteristics during deceleration such as the running resistance of the hybrid vehicle 1 and the effectiveness of the engine brake. The surrounding environment of the hybrid vehicle 1 during travel refers to the distance between the hybrid vehicle 1 and the preceding vehicle, whether the forward visibility of the hybrid vehicle 1 is good or bad, the number of vehicles existing around the hybrid vehicle 1 (traffic jam information), the road network and traffic light arrangement around the hybrid vehicle 1, the topography, weather, and the like. The distance between the vehicles and the forward visibility are acquired from images captured by a camera for capturing the forward view equipped in the hybrid vehicle 1, and the like. The number of vehicles existing around is acquired from VICS (Vehicle Information and Communication System, VICS is a registered trademark) and the like. The driver who drives the hybrid vehicle 1 is identified by an image captured by a camera for capturing images of the driver provided in the hybrid vehicle 1 or by the driver's own input to the setting unit 21. When a plurality of deceleration patterns serving as a reference (a deceleration pattern to which a specific value is appropriately multiplied according to the vehicle speed and deceleration of the hybrid vehicle 1) are stored, the setting unit 21 adjusts the deceleration pattern by selecting a deceleration pattern according to the above-mentioned adjustment reference information. On the other hand, when a single deceleration pattern serving as a reference is stored, the setting unit 21 adjusts the deceleration pattern according to the above-mentioned adjustment reference information (for example, multiplying the deceleration value at each vehicle speed by a value set for each vehicle speed based on the adjustment reference information). In addition, when a plurality of deceleration patterns serving as a reference are stored, after selecting a deceleration pattern based on a part of the above-mentioned adjustment reference information, the setting unit 21 may further adjust the deceleration pattern according to the adjustment reference information that was not used as a criterion for selecting the deceleration pattern.

[0036] When the hybrid vehicle 1 is decelerating and the allowable upper limit of the EG torque is greater than the required torque (between timing t5 and timing t7 in FIG. 2), the setting unit 21 refers to the deceleration pattern described in FIG. 4 to estimate the stop transition period s (see FIG. 5). Then, as described above, the setting unit 21 calculates the charging torque using the stop transition period s, and sets the EG torque to which the charging torque is added, and sets a negative MG torque according to the charging torque. As described above, the charging torque is calculated by dividing the net charging amount ΔSoC (see FIG. 2(C)) by the stop transition period f and the rotation speed of the motor generator 17.

[0037] Next, the calculation of the regenerative charge amount P used in calculating the net charge amount ΔSoC will be described with reference to Figs. 6 and 7. Fig. 6 is an explanatory diagram showing the regenerative charge amount P that is regenerated while the hybrid vehicle 1 decelerates at a constant deceleration and comes to a stop. The vertical axis of Fig. 6 indicates the regenerative charge amount P, and the horizontal axis of Fig. 6 indicates the vehicle speed of the hybrid vehicle 1. Each value on the vertical axis of Fig. 6 is a normalized value, with the regenerative charge amount P set to 1.0 when the hybrid vehicle 1, traveling at a speed of 120 km / h, decelerates at a constant deceleration and comes to a stop. As shown in Fig. 6, the regenerative charge amount P increases as the vehicle speed increases.

[0038] FIG. 7 is an explanatory diagram showing that when the hybrid vehicle 1 decelerates, the regenerative charge amount P varies depending on the value of the deceleration. The vertical axis of FIG. 7 indicates the regenerative charge amount P, and the horizontal axis of FIG. 7 indicates the deceleration. Each value on the vertical axis of FIG. 7 is a normalized value assuming that the regenerative charge amount P when the hybrid vehicle 1 decelerates at deceleration OD is 1.0. As shown in FIG. 7, in the hybrid vehicle 1, the regenerative charge amount P is maximum when the hybrid vehicle 1 decelerates at deceleration OD, and when the hybrid vehicle 1 decelerates at a deceleration smaller than or larger than deceleration OD, the regenerative charge amount P is smaller than when the hybrid vehicle 1 decelerates at deceleration OD.

[0039] In FIG. 7, the regenerative charge amount P becomes 0 at deceleration less than the deceleration mD, and therefore the deceleration when the driver depresses the accelerator pedal to 0 and the hybrid vehicle 1 is allowed to inertial travel is the deceleration mD. This deceleration mD is caused by friction loss in the power train and the running resistance of the hybrid vehicle 1. On the other hand, when the deceleration becomes greater than the deceleration OD, the torque required for deceleration exceeds the torque (charging torque) that can be regenerated by the motor generator 17, and therefore the mechanical friction brake operates and the regenerative charge amount P decreases. In this way, even if the hybrid vehicle 1 decelerates from the same vehicle speed, the regenerative charge amount P varies depending on the value of the deceleration. For example, between timing t1 and timing t5 in FIG. 2, the deceleration is smaller than the deceleration mD (the hybrid vehicle 1 is not decelerating), and therefore the regenerative charge amount P is 0. On the other hand, when deceleration starts from timing t5, the deceleration becomes greater than the deceleration mD, and the regenerative charge amount P begins to have a value. When the hybrid vehicle 1 is decelerating, the setting unit 21 refers to the vehicle speed and deceleration of the hybrid vehicle 1 included in the traveling information collected by the information collecting unit 27, and assumes that the hybrid vehicle 1 will decelerate while maintaining the deceleration, and calculates the regenerative charge amount P using a map or a formula in which the vehicle speed value (FIG. 6) and the deceleration value (FIG. 7) are input and the regenerative charge amount P is output. The map or formula is expressed in the form of, for example, regenerative charge amount P=vehicle speed effect×deceleration effect. Furthermore, the weighting of the vehicle speed value and the deceleration value in the map or formula may be set arbitrarily.

[0040] 8 is a flowchart showing the procedure of the torque setting process. The torque setting process is periodically executed while the hybrid vehicle 1 is traveling. When the torque setting process is started, the setting unit 21 first determines whether the required torque required of the hybrid vehicle 1 is greater than the allowable upper limit of the EG torque (step S11).

[0041] If the required torque is greater than the allowable upper limit of the EG torque (step S11: YES), the setting unit 21 sets an EG torque equal to or less than the allowable upper limit, and sets the difference between this EG torque and the required torque as the MG torque (step S13). In other words, the setting unit 21 sets the EG torque equal to or less than the allowable upper limit so that the sum of the EG torque and the MG torque is equal to the required torque, and also sets the MG torque. After setting each of the EG torque and the MG torque (step S13), the setting unit 21 ends the torque setting process.

[0042] On the other hand, if the allowable upper limit of the EG torque is greater than the required torque (step S11: NO), the setting unit 21 determines whether the hybrid vehicle 1 is decelerating (step S15). In detail, the setting unit 21 refers to the traveling information periodically collected by the information collecting unit 27, and determines whether the hybrid vehicle 1 is decelerating based on the acceleration of the hybrid vehicle 1 indicated by the traveling information. In this embodiment, if the acceleration indicated by the traveling information is negative acceleration (deceleration), the hybrid vehicle 1 is deemed to be decelerating. If the hybrid vehicle 1 is not decelerating (step S15: NO), the setting unit 21 ends the torque setting process.

[0043] On the other hand, if the hybrid vehicle 1 is decelerating (step S15: YES), the setting unit 21 refers to the deceleration pattern (FIG. 4) and calculates the charging torque (step S17). In detail, the setting unit 21 estimates the stop transition period s (FIG. 5) by referring to the deceleration pattern (FIG. 4), and calculates the charging torque by dividing the net charging amount ΔSoC (FIG. 2) by the estimated stop transition period f and the rotation speed of the motor generator 17. The rotation speed of the motor generator 17 can be referred to from the traveling information periodically collected by the information collecting unit 27.

[0044] After calculating the charging torque (step S17), the setting unit 21 sets the EG torque to which the charging torque is added, and sets a negative MG torque according to the charging torque (step S19). After that, the setting unit 21 ends the torque setting process.

[0045] FIG. 9 is an explanatory diagram showing the change over time in the vehicle speed and the current charge amount CC of the secondary battery 18 when the hybrid vehicle 1 is driven in WLTC (Worldwide harmonized Light duty driving Test Cycle) mode on a vehicle simulation program. The vertical axis of FIG. 9(A) shows the vehicle speed of the hybrid vehicle 1, and the vertical axis of FIG. 9(B) shows the current charge amount CC of the secondary battery 18. The horizontal axis of FIG. 9(A) and (B) shows time. That is, the hybrid vehicle 1 starts to drive at the left end of the horizontal axis, and the hybrid vehicle 1 stops to drive (ignition is turned off) at the right end of the horizontal axis. FIG. 9(B) also shows the target charge amount ST.

[0046] As shown in Fig. 9(A), the hybrid vehicle 1 stops several times before stopping, but as shown in Fig. 9(B), the secondary battery 18 is charged every time the vehicle starts decelerating to stop. Since the hybrid vehicle 1 travels in urban areas, suburban areas, and expressways in that order, the vehicle speed tends to increase toward the right along the horizontal axis (as time passes), as shown in Fig. 9(A). Accordingly, as shown in Fig. 9(B), the decrease in the current charge amount CC increases, but the increase in the current charge amount CC due to charging during deceleration (charging from timing t5 to timing t7 illustrated in Fig. 2(C)) also increases.

[0047] In an evaluation of running in the WLTC mode described in FIG. 9, the hybrid vehicle 1 had a fuel efficiency improvement rate of 19.1% and a reduction rate of nitrogen oxides (NOx) in the exhaust gas of 32.6% compared to a comparative vehicle that does not have the secondary battery 18 and is driven only by an engine. The exhaust gas evaluated at this time was exhaust gas before passing through an exhaust purification catalyst. In addition, the current charge amount CC of the hybrid vehicle 1 after running in the WLTC mode compared to before running in the same mode was 101.8%, which showed that the hybrid vehicle 1 can continuously achieve the effect of reducing exhaust gas by assisting the EG torque with the MG torque (torque assist).

[0048] According to the hybrid vehicle 1 equipped with the control device 20 of the first embodiment described above, the EG torque with the charging torque added thereto during deceleration is set, 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. In addition, since the stop transition period f is estimated by referring to the deceleration pattern, the estimation accuracy of the stop transition period f can be improved. Furthermore, since the charging torque is calculated using the stop transition period f, it is possible to suppress the occurrence of an excess or deficiency in the charge amount of the secondary battery 18 when the hybrid vehicle 1 is stopped. As a result, the torque assist by the motor generator 17 during acceleration (assistance by the MG torque when the required torque is larger than the allowable upper limit of the EG torque) is ensured, so that the effect of improving fuel efficiency and the effect of reducing exhaust gas due to the torque assist can be continuously obtained. In addition, it is also possible to avoid excess fuel consumption due to a decrease in the charge / discharge efficiency of the secondary battery 18 that occurs when the current charge amount CC becomes excessive.

[0049] Furthermore, in the hybrid vehicle 1 equipped with the control device 20 of the first embodiment, the setting unit 21 calculates the charging torque using the subtraction charge amount ΔSoC (the charging amount obtained by subtracting the regenerative charging amount P and the current charging amount CC from the target charging amount ST) and the vehicle stop transition period f. Therefore, since the charging torque is calculated using the subtraction charge amount ΔSoC taking into account the regenerative charging amount P, it is possible to prevent the current charging 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 prevent excess fuel consumption due to a decrease in the charging and discharging efficiency of the secondary battery 18 that occurs when the current charging amount CC becomes excessive.

[0050] Furthermore, in the hybrid vehicle 1 equipped with the control device 20 of the first embodiment, the setting unit 21 can refer to a deceleration pattern adjusted according to adjustment reference information (characteristics of the hybrid vehicle 1, the surrounding environment of the hybrid vehicle 1 while traveling, and the driver who is driving the hybrid vehicle 1). As a result, since it is possible to refer to a deceleration pattern adjusted according to the situation, it is possible to further improve the estimation accuracy of the stop transition period f. Therefore, since the calculation accuracy of the charging torque is also improved, it is possible to further prevent the current charge amount CC of the secondary battery 18 from being excessive or insufficient when the hybrid vehicle 1 is stopped.

[0051] <Second embodiment> Fig. 10 is a flowchart showing the procedure of the torque setting process performed in a hybrid vehicle equipped with the control device of the second embodiment. In the torque setting process (Fig. 10) performed in the second embodiment, the processes of step S16 and steps S21 and S23 are further added to the torque setting process (Fig. 8) described in the first embodiment. In the description of Fig. 10, the description of steps S11, S13, S15, S17, and S19 that are the same as those in Fig. 8 will be omitted.

[0052] In the second embodiment, when the hybrid vehicle is decelerating (step S15: YES), the setting unit 21 determines whether the hybrid vehicle is decelerating at a deceleration smaller than a reference deceleration that is preset as a reference (step S16). The reference deceleration is a deceleration that is considered to be extremely small. When the hybrid vehicle is decelerating at a deceleration smaller than the reference deceleration, for example, when the reference deceleration is deceleration mD (FIG. 7), the hybrid vehicle is decelerating at a deceleration value that is on the left side of the deceleration mD on the horizontal axis in FIG. 7. When the hybrid vehicle is not decelerating at a deceleration smaller than the reference deceleration (step S16: NO), that is, when the hybrid vehicle is decelerating at a deceleration larger than the reference deceleration, the setting unit 21 executes the processes of steps S17 and S19, similarly to the first embodiment.

[0053] On the other hand, when the hybrid vehicle is decelerating at a deceleration rate smaller than the reference deceleration rate (step S16: YES), or when the hybrid vehicle is not decelerating (step S15: NO), the setting unit 21 refers to the lower limit deceleration pattern and calculates the charging torque (step S21). The lower limit deceleration pattern is a deceleration pattern obtained by multiplying the reference deceleration pattern DP by a lower limit magnification rate set in advance. In this embodiment, the lower limit magnification rate is set to 0.1, but any value smaller than 1 is set. In step S21, the setting unit 21 estimates the stop transition period s by referring to the lower limit deceleration pattern, and calculates the charging torque by dividing the subtracted charge amount ΔSoC (FIG. 2) by the estimated stop transition period f and the rotation speed of the motor generator 17. In this embodiment, since the lower limit magnification rate is 0.1, the stop transition period s is estimated by applying the vehicle speed of the hybrid vehicle 1 to the curve CVa shown in FIG. 5.

[0054] After calculating the charging torque by referring to the lower limit deceleration pattern (step S21), the setting unit 21 sets the EG torque to which the charging torque is added, and sets a negative MG torque according to the charging torque (step S23). After that, the setting unit 21 ends the torque setting process.

[0055] One of the triggers for executing step S21 and step S23 is that the hybrid vehicle decelerates at a deceleration smaller than the reference deceleration (step S16: YES). Even when the hybrid vehicle is decelerating, if the deceleration is extremely small, the stop transition period f estimated by setting an extension line along the gradient at the time of deceleration is lengthened according to the estimation method of the stop transition period f described in FIG. 3 (as described in FIG. 5, the stop transition period f is also lengthened when it is estimated using the deceleration pattern of FIG. 4). Then, the charging torque calculated using such a lengthened stop transition period f becomes small, so there is a risk of the charging efficiency being significantly reduced. In this embodiment, in consideration of the above point, when the hybrid vehicle is decelerating 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). In this way, a significant decrease in the charging efficiency by the motor generator 17 when the hybrid vehicle is decelerating at a deceleration smaller than the reference deceleration is suppressed.

[0056] Another trigger for executing step S21 and step S23 is when the hybrid vehicle is not decelerating (step S15: NO). In the torque setting process executed while the hybrid vehicle 1 is running, when the hybrid vehicle is not decelerating, it means when the hybrid vehicle is accelerating or running at a constant speed. In this case, according to the estimation method of the stop transition period f described in FIG. 3, even if an extension line (illustrated as extension lines La, Lb) along the slope at the time of running is set, the stop transition period f cannot be estimated (becomes infinite). In this respect, in this embodiment, even when the hybrid vehicle is not decelerating (when the hybrid vehicle is accelerating or running at a constant speed), it is assumed that the allowable upper limit of the EG torque is larger than the required torque (step S11: NO), and the charging torque is calculated by referring to the lower limit deceleration pattern (step S21). In this way, even when the hybrid vehicle is accelerating or running at a constant speed, it is possible to charge the secondary battery 18 by setting a negative MG torque according to the charging torque.

[0057] In the second embodiment described above, similarly to the first embodiment, by ensuring torque assist by motor generator 17 during acceleration, it is possible to continuously obtain the effects of improving fuel efficiency and reducing exhaust gases due to the torque assist.

[0058] Furthermore, in the second embodiment, when the hybrid vehicle is decelerating at a deceleration smaller than the reference deceleration (step S16: YES), the charging torque is calculated using the stop transition period f estimated with reference to the lower limit deceleration pattern, so that the secondary battery 18 can be charged more efficiently than when a deceleration pattern based on a deceleration smaller than the reference deceleration (a deceleration pattern adjusted to match deceleration smaller than the reference deceleration by multiplying the reference deceleration pattern by a specific value, see Figure 4) is referenced.

[0059] In the second embodiment, even when the hybrid vehicle is accelerating or running at a constant speed, the charging torque is calculated using the stop transition period f estimated with reference to the lower limit deceleration pattern, so that the secondary battery 18 can be charged even when the hybrid vehicle is accelerating or running at a constant speed. Therefore, even when the hybrid vehicle is not decelerated frequently, it is possible to prevent the charge amount of the secondary battery 18 from becoming insufficient.

[0060] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible. · It is not necessary to adjust according to all adjustment criteria information.

[0061] [Variation 1] In the above embodiment, the control device 20 includes the EG drive control unit 23 and the MG drive control unit 25, but is not limited to this. The control device 20 does not need to include the EG drive control unit 23 and the MG drive control unit 25. In such a case, the EG drive control unit 23 and the MG drive control unit 25 provided outside the control device 20 in the hybrid vehicle 1 receive the EG torque and the MG torque set by the setting unit 21, and then drive the engine 11 and the motor generator 17 according to the EG torque and the MG torque.

[0062] [Variation 2] In the above embodiment, the secondary battery 18 is used as the power storage unit, but this is not limiting. For example, the power storage unit may be a capacitor.

[0063] [Variation 3] In the above embodiment, the deceleration pattern is adjustable according to all three pieces of adjustment reference information, but this is not limited thereto. For example, the deceleration pattern may be adjustable according to at least one of the three pieces of adjustment reference information.

[0064] [Variation 4] In the second embodiment, the charging torque is calculated (step S21) by referring to the lower limit deceleration pattern when either the hybrid vehicle is not decelerating (step S15: NO) or the hybrid vehicle is decelerating at a deceleration rate smaller than the reference deceleration (step S16: YES), but this is not limited to the above. For example, the charging torque may not be calculated (step S21) when the hybrid vehicle is not decelerating (step S15: NO), and the charging torque may be calculated (step S21) only when the hybrid vehicle is decelerating at a deceleration rate smaller than the reference deceleration (step S16: YES). Similarly, the charging torque may be calculated (step S21) only when the hybrid vehicle is not decelerating (step S15: NO), and the charging torque may not be calculated (step S21) when the hybrid vehicle is decelerating at a deceleration rate smaller than the reference deceleration (step S16: YES).

[0065] [Variation 5] In the second embodiment, the lower limit deceleration pattern is a deceleration pattern obtained by multiplying the reference deceleration pattern DP by a lower limit magnification factor that is set in advance, but is not limited to this. For example, the lower limit deceleration pattern may be created in advance without multiplying the deceleration pattern DP by a lower limit magnification factor.

[0066] Although the present aspect has been described above based on the embodiment and modified examples, the above-mentioned embodiment of the aspect is intended to facilitate understanding of the present aspect and does not limit the present aspect. The present aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in the present aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

[0067] The present invention can also be realized in the following forms. [Application example 1] A control device for a hybrid vehicle including an engine and a motor generator as drive sources, and a power storage unit that supplies electric power to the motor generator and stores electric power generated by the motor generator, a setting unit that sets an engine torque output from the engine and a motor generator torque output from the motor generator in accordance with a required torque required for the hybrid vehicle; an information collecting unit that collects driving information including at least a current vehicle speed and acceleration of the hybrid vehicle; The control device for a hybrid vehicle, when the hybrid vehicle is decelerating and an allowable upper limit of the engine torque at which output is permitted becomes greater than the required torque, the setting unit refers to the vehicle speed indicated by the traveling information and a deceleration pattern that estimates a change over time in deceleration of the hybrid vehicle traveling at a deceleration that is negative of the acceleration until the hybrid vehicle comes to a stop, estimates a stop transition period until the hybrid vehicle comes to a stop, calculates a charging torque for charging the power storage unit using the stop transition period, sets the engine torque plus the charging torque, and sets a negative motor generator torque corresponding to the charging torque. [Application example 2] A control device for a hybrid vehicle according to Application Example 1, The control device for a hybrid vehicle, when the hybrid vehicle is decelerating at a deceleration smaller than a reference deceleration preset as a standard and the allowable upper limit of the engine torque is greater than the required torque, the setting unit estimates the stop transition period by referring to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit multiplier preset, calculates the charging torque using the stop transition period, sets the engine torque plus the charging torque, and sets a negative motor generator torque corresponding to the charging torque. [Application example 3] The control device for a hybrid vehicle according to the first or second aspect of the present invention, The control device for a hybrid vehicle, when the hybrid vehicle is accelerating or traveling at a constant speed and the allowable upper limit of the engine torque is greater than the required torque, the setting unit estimates the stop transition period by referring to a lower limit deceleration pattern multiplied by a preset lower limit multiplier to the deceleration pattern, calculates the charging torque using the stop transition period, sets the engine torque plus the charging torque, and sets a negative motor generator torque corresponding to the charging torque. [Application example 4] A control device for a hybrid vehicle according to any one of Application Examples 1 to 3, The control device for a hybrid vehicle, wherein the setting unit calculates the charging torque using a subtracted charge amount obtained by subtracting a current charge amount of the power storage unit and a regenerative charge amount that can be regenerated before the hybrid vehicle comes to a stop from a target charge amount that is a target for the charge amount of the power storage unit, and the stop transition period. [Application example 5] A control device for a hybrid vehicle according to any one of Application Examples 1 to 4, A control device for a hybrid vehicle, wherein the setting unit is capable of referring to the deceleration pattern adjusted according to at least one of characteristics of the hybrid vehicle, the surrounding environment of the hybrid vehicle while traveling, and a driver driving the hybrid vehicle. [Explanation of symbols]

[0068] 1. Hybrid vehicle 11…Engine 12…Gearbox 13…Propeller shaft 14…Differential gear 15…Drive shaft 16…Tire 17...Motor generator 18…Secondary battery 20...Control device 21. Setting section 23...EG drive control unit 25...MG drive control unit 27…Information Gathering Department

Claims

1. A control device for a hybrid vehicle including an engine and a motor generator as drive sources, and a power storage unit that supplies electric power to the motor generator and stores electric power generated by the motor generator, a setting unit that sets an engine torque output from the engine and a motor generator torque output from the motor generator in accordance with a required torque required for the hybrid vehicle; an information collecting unit that collects driving information including at least a current vehicle speed and acceleration of the hybrid vehicle; The control device for a hybrid vehicle, when the hybrid vehicle is decelerating and an allowable upper limit of the engine torque at which output is permitted becomes greater than the required torque, the setting unit refers to the vehicle speed indicated by the traveling information and a deceleration pattern that estimates a change over time in deceleration of the hybrid vehicle traveling at a deceleration that is negative of the acceleration until the hybrid vehicle comes to a stop, estimates a stop transition period until the hybrid vehicle comes to a stop, calculates a charging torque for charging the power storage unit using the stop transition period, sets the engine torque plus the charging torque, and sets a negative motor generator torque corresponding to the charging torque.

2. The control device for a hybrid vehicle according to claim 1, The control device for a hybrid vehicle, when the hybrid vehicle is decelerating at a deceleration smaller than a reference deceleration preset as a standard and the allowable upper limit of the engine torque is greater than the required torque, the setting unit estimates the stop transition period by referring to a lower limit deceleration pattern obtained by multiplying the deceleration pattern by a lower limit multiplier preset, calculates the charging torque using the stop transition period, sets the engine torque plus the charging torque, and sets a negative motor generator torque corresponding to the charging torque.

3. The control device for a hybrid vehicle according to claim 1, The control device for a hybrid vehicle, when the hybrid vehicle is accelerating or traveling at a constant speed and the allowable upper limit of the engine torque is greater than the required torque, the setting unit estimates the stop transition period by referring to a lower limit deceleration pattern multiplied by a preset lower limit multiplier to the deceleration pattern, calculates the charging torque using the stop transition period, sets the engine torque plus the charging torque, and sets a negative motor generator torque corresponding to the charging torque.

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

5. A control device for a hybrid vehicle according to any one of claims 1 to 4, A control device for a hybrid vehicle, wherein the setting unit is capable of referring to the deceleration pattern adjusted according to at least one of the characteristics of the hybrid vehicle, the surrounding environment of the hybrid vehicle while traveling, and the driver driving the hybrid vehicle.

Images