JP2016222100A - Drive control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control system that can control a battery to a proper SOC without impairing fuel economy improvement effect.SOLUTION: In the drive control system, a determination torque calculation part 23 calculates a determination torque obtained based on an engine torque when an engine 2 is operated at an operation point that shows good heat efficiency in accordance with SOC of the battery 11, and an operation control part 24 controls operation of the engine 2 and a motor 3 by a target engine torque and a target motor torque obtained based on a relationship between a driver's request torque and the determination torque.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive control system that controls engine operation based on a target engine torque and controls motor operation based on a target motor torque.

  In a hybrid vehicle running with an engine and a motor, the drive control system determines the target engine torque and the target motor torque so as to satisfy the driver's required torque.

  In this type of conventional drive control system, for the purpose of improving fuel efficiency, it is determined whether or not there is an engine operating point in a predetermined region determined based on the maximum thermal efficiency line, and the engine operating point is in the predetermined region. In the case where the engine operating point does not exist, the engine operating point is corrected so as to be within a predetermined region.

JP 2013-071467 A

  Here, when the battery that charges and discharges with the motor becomes overcharged or overdischarged, the deterioration proceeds. Therefore, it is required to manage the SOC (State of Charge) of the battery so as to be within a predetermined range (for example, 40% to 80%).

  However, in the device described in Patent Document 1, the engine operating point is determined only from the viewpoint of improving fuel efficiency, and the engine operating point is not determined in consideration of the SOC of the battery. For this reason, although the thing of patent document 1 can implement | achieve an improvement in a fuel consumption by correct | amending an engine operating point in the predetermined | prescribed area | region, it does not consider about SOC of a battery and a battery is overcharged. Or it may become an overdischarge.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a drive control system that can manage the SOC of an appropriate battery without impairing the fuel efficiency improvement effect.

  One aspect of the invention of a drive control system that solves the above problems is to detect an accelerator operation amount in a drive control system that controls engine operation based on a target engine torque and controls motor operation based on the target motor torque. An accelerator operation amount detection unit that detects the engine speed, an engine speed detection unit that detects the engine speed, a request torque calculation unit that calculates a driver's request torque based on the accelerator operation amount and the engine speed, and battery charging A remaining charge detection unit that detects the remaining amount, and a determination torque that is calculated based on the engine torque when the engine is operated at a heat efficient operating point, according to the remaining charge of the battery. A target engine torque and a target motor obtained based on a relationship between the calculation unit and the required torque and the determination torque The torque, and from those having an operation control unit for controlling the operation of the engine and the motor.

  Thus, according to the present invention, the determination torque used when determining the target engine torque and the target motor torque is set based on the engine torque when the engine is operated at an operating point with good thermal efficiency. The determination torque corresponding to the remaining charge amount is calculated. Since the operation of the engine and the motor is controlled using the determination torque calculated in this manner, it is possible to manage the SOC of the battery appropriately without impairing the fuel efficiency improvement effect.

FIG. 1 is a diagram illustrating a drive control system according to an embodiment of the present invention, and is a configuration diagram illustrating a vehicle including the drive control system. FIG. 2 is a diagram showing a determination torque map used in the drive control system according to the embodiment of the present invention. FIG. 3 is a diagram showing a power generation determination torque map used in the drive control system according to the embodiment of the present invention in a tabular format. FIG. 4 is a table showing a discharge determination torque map used in the drive control system according to the embodiment of the present invention in a tabular form. FIG. 5 is a graph showing a power generation determination torque map used in the drive control system according to the embodiment of the present invention in a graph format. FIG. 6 is a graph showing a discharge determination torque map used in the drive control system according to the embodiment of the present invention in a graph format. FIG. 7 is a flowchart showing an engine operating point determination process executed by the drive control system according to the embodiment of the present invention. FIG. 8 is a diagram illustrating a state in which the engine operating point is determined so that the motor generates power in the drive control system according to the embodiment of the present invention. FIG. 9 is a diagram showing a state where the engine operating point is determined so that the motor discharges in the drive control system according to the embodiment of the present invention. FIG. 10 is a diagram illustrating a state in which the engine operating point is determined so that the motor does not operate based on the determination torque map when the SOC is 60% in the drive control system according to the embodiment of the present invention. . FIG. 11 is a diagram showing a list of target engine operating points and motor torques with respect to required torque in the drive control system according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIGS. 1-11 is a figure explaining embodiment of the drive control system which concerns on embodiment of this invention.

  As shown in FIG. 1, a vehicle 1 equipped with a drive control system according to an embodiment of the present invention includes an engine 2, a transmission 4, and wheels 6.

  The engine 2 is composed of, for example, a 4-cycle gasoline engine, and generates power for driving the vehicle.

  The transmission 4 changes the power generated by the engine 2. The transmission 4 includes a clutch 7, and the power from the engine 2 is interrupted by the clutch 7.

  The transmission 4 includes a ring gear 5. The ring gear 5 constitutes a differential device together with a pinion gear, a side gear, and the like (not shown). Wheels 6 are connected to the side gear of the differential device via left and right drive shafts 5a. The power shifted by the transmission 4 is input to the ring gear 5 and then transmitted to the left and right wheels 6.

  The vehicle 1 includes a motor 3, a speed reducer 8, a battery 11, an inverter 12, and an ECU 20.

  The motor 3 is a rotating electrical machine that functions as an electric motor and a generator, and is connected to a battery 11 via an inverter 12. The motor 3 generates power running torque or power generation torque (regenerative torque) by the ECU 20 controlling the inverter 12.

  The motor 3 is connected to the ring gear 5 via the speed reducer 8 and assists the traveling of the vehicle 1 by powering with the electric power supplied from the battery 11. The motor 3 generates power by being driven by the power transmitted from the ring gear 5.

  Thus, the vehicle 1 in the present embodiment is configured as a hybrid vehicle capable of assisting the power of the engine 2 by the motor 3. The motor 3 is not limited to the ring gear 5 but may be connected to the power transmission path from the engine 2 to the wheels 6.

  The vehicle 1 also includes an accelerator operation amount detection unit 16 and an engine speed detection unit 17. The accelerator operation amount detector 16 is provided, for example, in an accelerator pedal (not shown) and detects the accelerator operation amount. The engine speed detector 17 is provided, for example, on the crankshaft of the engine 2 and detects the engine speed.

  The ECU 20 includes a computer unit that includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), a flash memory, an input port, an output port, and a network module. ing.

  A program for causing the computer unit to function as the ECU 20 is stored in the ROM of the ECU 20 together with various constants, various maps, and the like. That is, in the ECU 20, the computer unit functions as the ECU 20 when the CPU executes a program stored in the ROM.

  The ECU 20 determines the target engine torque and the target motor torque so as to satisfy the driver's required torque. Then, the ECU 20 controls the operation of the engine 2 based on the target engine torque, and controls the operation of the motor 3 based on the target motor torque.

  The ECU 20 includes a request torque calculation unit 21 that calculates the driver's request torque and a remaining charge detection unit 22 that detects the remaining charge of the battery 11. Hereinafter, the remaining charge of the battery 11 is referred to as SOC (State Of Charge).

  The required torque calculation unit 21 calculates the driver's required torque based on the accelerator operation amount detected by the accelerator operation amount detection unit 16 and the engine speed detected by the engine speed detection unit 17.

  Note that, as another embodiment of the present invention, the vehicle 1 includes a vehicle speed detection unit 18 that detects the traveling speed of the vehicle, and is detected by the accelerator operation amount detected by the accelerator operation amount detection unit 16 and the vehicle speed detection unit 18. The required torque of the driver may be calculated based on the travel speed of the vehicle.

  The remaining charge detection unit 22 detects the SOC by measuring and integrating the current input to and output from the battery 11 with the current sensor 13. The SOC is a value (%) represented by “current remaining capacity / full charge capacity × 100” of the battery 11.

  The ECU 20 includes a determination torque calculation unit 23 and an operation control unit 24.

  The determination torque calculation unit 23 calculates a determination torque obtained based on the engine torque when the engine 2 is operated at an operating point with good thermal efficiency according to the SOC of the battery 11. As described later, the determination torque includes a power generation determination torque α and a discharge determination torque β.

  The operation control unit 24 controls the operations of the engine 2 and the motor 3 based on the target engine torque and the target motor torque obtained based on the relationship between the required torque and the determination torque.

  The ROM of the ECU 20 is referred to when the engine operating point (target engine torque) is determined, the power generation determination torque map referred to when the power generation determination torque α is calculated, and the discharge determination torque β. The discharge determination torque map is stored. These determination torque map, power generation determination torque map, and discharge determination torque map are obtained from experiments and the like.

  As shown in FIG. 2, the determination torque map is obtained by determining the power generation determination torque α and the discharge determination torque β as the determination torque for each engine rotation speed with the torque and the engine rotation speed as the vertical axis and the horizontal axis, respectively. is there.

  The torque line of the power generation determination torque α is set below the optimum thermal efficiency line so as to be substantially parallel to the optimum thermal efficiency line. The torque line of the discharge determination torque β is set above the optimum thermal efficiency line so as to be substantially parallel to the optimum thermal efficiency line.

  Therefore, the torque line of the power generation determination torque α and the torque line of the discharge determination torque β are set so as to be substantially parallel to each other across the thermal efficiency optimum line.

  Here, the optimum thermal efficiency line is a line that passes through the center of the engine efficiency line indicated by the chain line, and determines the engine torque for operating the engine 2 at an operating point with good thermal efficiency for each engine speed. .

  Therefore, in the determination torque map, the region sandwiched between the torque line of the power generation determination torque α and the torque line of the discharge determination torque β has higher thermal efficiency of the engine 2 and can improve the fuel efficiency of the engine 2 than outside this region. This is an important area.

  In the present embodiment, the ECU 20 sets the target engine torque so that the operating point of the engine 2 is in a region sandwiched between the torque line of the power generation determination torque α and the torque line of the discharge determination torque β.

  Further, the power generation determination torque α and the discharge determination torque β are changed according to the SOC of the battery 11. Specifically, the torque line of the power generation determination torque α is set downward as the SOC increases. That is, as shown in FIG. 5, when the SOC of the battery 11 is low, the battery 11 is not overcharged even if power generation is performed by the operation of the engine 2, so that the operation of the engine 2 with a large torque is allowed. Such a torque line of engine torque is set. On the other hand, when the SOC of the battery 11 is high, there is a possibility of overcharging when power is generated by the operation of the engine 2. Therefore, the torque of the engine torque such that power generation is not actively performed by the operation of the engine 2. A line is set.

  Further, as shown in FIG. 6, the torque line of the discharge determination torque β is set upward as the SOC decreases. That is, when the SOC of the battery 11 is high, the battery 11 is not overdischarged even when the motor 3 is actively operated and discharged, so that the torque that allows the operation of the engine 2 to be a small torque is allowed. A line is set. On the other hand, when the SOC of the battery 11 is low, there is a possibility of overdischarge if the motor 3 is actively operated. Therefore, an engine torque torque line is set so that the engine 2 operates actively.

  For example, as shown in FIG. 2, when the driver's required torque A is smaller than the power generation determination torque α, the ECU 20 operates the engine 2 with the power generation determination torque α as an engine operating point (target engine torque). When the SOC of the battery 11 is higher than the SOC of the battery 11 corresponding to the power generation determination torque α, the ECU 20 sets the power generation determination torque α ′ corresponding to the higher SOC of the battery 11 to the engine operating point (target engine torque). Then, the engine 2 is operated.

  That is, the ECU 20 obtains the target engine torque based on the relationship between the power generation determination torque α set according to the SOC of the battery 11 and the driver's required torque A, and the target engine thus obtained is obtained. The operation of the engine 2 is controlled based on the torque. As a result, it is possible to manage the SOC of an appropriate battery without impairing the fuel efficiency improvement effect.

  The power generation determination torque α is calculated by the determination torque calculation unit 23 of the ECU 20 with reference to the power generation determination torque maps shown in FIGS. Here, FIG. 3 shows the power generation determination torque map in a tabular format, and FIG. 5 shows the power generation determination torque map in a graph format.

  Here, in the present embodiment, the SOC management range of the battery 11 is set to 40% to 80% in order to prevent the battery 11 from being overcharged or overdischarged to cause deterioration.

  In the power generation determination torque maps shown in FIGS. 3 and 5, the torque line of the power generation determination torque α is set to be lower as the SOC becomes higher.

  That is, when the SOC is 40%, it is necessary to actively generate power by operating the engine 2 in order to prevent the SOC from further decreasing and causing overdischarge. Set higher than%.

  When the SOC is 60%, it is not necessary to generate power more actively than when the SOC is 40%. Therefore, the power generation determination torque α is set lower than when the SOC is 40%.

  Further, when the SOC is 80% or more, if the power generation is performed by the operation of the engine 2, the SOC further rises and becomes overcharged. Regardless, the power generation determination torque α is 0N.

  The power generation determination torque α when the SOC is 80% or more is not limited to 0 N, and may be a very low value so that excessive charging is not performed by the operation of the engine 2.

  The discharge determination torque β is calculated by the determination torque calculation unit 23 of the ECU 20 with reference to the discharge determination torque map shown in FIGS. Here, FIG. 4 shows the discharge determination torque map in a table format, and FIG. 6 shows the discharge determination torque map in a graph format.

  In the discharge determination torque map shown in FIGS. 4 and 6, the torque line of the discharge determination torque β is set to be higher as the SOC becomes lower.

  That is, when the SOC of the battery 11 is 80%, it is necessary to discharge the motor 3 by actively operating the motor 3 in order to prevent the SOC from further rising and being overcharged. , The SOC is set lower than when it is 60%.

  Further, when the SOC is 60%, it is not necessary to operate the motor 3 more actively than when the SOC is 80%. Therefore, the discharge determination torque β is set higher than when the SOC is 80%.

  Further, when the SOC is 40% or less, if the discharge is performed by the operation of the motor 3, the SOC further decreases and becomes overdischarged. Therefore, the engine speed is set so that the discharge is not performed by the operation of the motor 3. Regardless, the discharge determination torque β is 200N. Here, 200N is a value larger than the maximum torque that the engine 2 can generate.

  Note that the discharge determination torque β when the SOC is 40% or less is not limited to 200 N, and may be a very high value such that excessive discharge is not performed by the operation of the motor 3.

  As described above, in this embodiment, the engine is not operated on one thermal efficiency optimum line as in the prior art, but the thermal efficiency optimum line is sandwiched between the two torque lines of the power generation determination torque α and the discharge determination torque β. Since the engine 2 is operated in the region set in this way, the fuel efficiency improvement effect is not impaired. Further, by changing the two torque lines of the power generation determination torque α and the discharge determination torque β in accordance with the SOC, the engine 2 is configured so that the battery 11 is not overcharged or overdischarged while satisfying the driver's required torque A. And the motor 3 can be operated.

  Engine operating point determination processing by the drive control system according to the present embodiment configured as described above will be described with reference to the flowchart of FIG.

  As shown in FIG. 7, first, the ECU 20 detects the accelerator operation amount by the accelerator operation amount detector 16 and detects the engine speed by the engine speed detector 17 (step S1).

  Next, the ECU 20 calculates the required torque A of the driver by the required torque calculation unit 21 based on the accelerator operation amount and the engine speed detected in step S1 (step S2). The ECU 20 may detect the vehicle speed instead of the engine speed at step S1, and calculate the required torque A based on the vehicle speed and the accelerator operation amount at step S2.

  Next, the ECU 20 detects the SOC of the battery 11 by the remaining charge detection unit 22 (step S3).

  Next, the ECU 20 calculates a power generation determination torque α based on the SOC and the engine speed (step S4).

  Next, the ECU 20 calculates whether or not the required torque A is smaller than the power generation determination torque α (step S5).

  When the determination in step S5 is “YES” (when the required torque A is smaller than the power generation determination torque α), the ECU 20 determines a target engine operating point (target engine torque) and a target motor torque in step S6.

  Specifically, the ECU 20 sets the target engine operating point (target engine torque) to a value equal to the power generation determination torque α.

  Here, the difference between the target engine torque and the required torque A is set as the target motor torque. Specifically, when the required torque A is smaller than the power generation determination torque α, that is, when the target engine torque is set to a value equal to the power generation determination torque α, the target engine torque and the required torque are α−A. The difference is set as the target motor torque, and the operation of the motor 3 is controlled. At this time, since the required torque A is smaller than the power generation determination torque α, the ECU 20 operates the engine 2 with a target engine torque α that is larger than the driver's required torque A, but an excess amount exceeding the driver's required torque A. The operation of the engine 2 with the engine torque of the above is used for the operation of the motor 3 to generate power. In this way, since the engine 2 is operated at a heat efficient operating point, fuel efficiency can be improved, and the motor 3 is operated at an engine torque exceeding the driver's required torque. Since it is used for power generation, energy can be used efficiently. Further, the ECU 20 calculates the power generation determination torque α according to the SOC and sets the target engine torque based on the relationship between the power generation determination torque α and the driver's required torque A, so that the fuel efficiency improvement effect is not impaired. Overcharging of the battery 11 can be prevented.

  Here, in the drive control system according to the present embodiment, the target motor torque is the difference between the target engine torque and the required torque A. Therefore, when the torque of the motor 3 during power running is a positive value B, the target motor torque The relationship of engine torque = A + B is established. Therefore, in step S6, the ECU 20 sets the target motor torque to a negative value -B that is the torque of the motor 3 during power generation. In this way, the motor 3 generates power with a power generation torque that is the difference between the target engine torque and the required torque A. Thereafter, the ECU 20 ends the process of the flowchart of FIG.

  On the other hand, when the determination in step S5 is “NO” (when the required torque A is equal to or greater than the power generation determination torque α), the ECU 20 calculates the discharge determination torque β based on the SOC of the battery 11 and the engine speed (step S5). S7).

  Next, the ECU 20 calculates whether or not the required torque A is equal to or less than the discharge determination torque β (step S8).

  When the determination in step S8 is “YES” (when the required torque A is equal to or less than the discharge determination torque β), the ECU 20 sets the target engine operating point (target engine torque) to a value equal to the required torque A, and the target The motor torque is set to 0 (step S9). That is, since the ECU 20 operates the engine 2 at an operating point with good thermal efficiency and does not operate the motor 3, the battery 11 is neither overcharged nor overdischarged. At this time, since the target engine torque is set based on the power generation determination torque α and the discharge determination torque β according to the SOC of the battery 11, the SOC of the battery 11 is sufficiently secured. In this way, the drive control system according to the present embodiment can manage the SOC of an appropriate battery without impairing the fuel efficiency improvement effect. Thereafter, the ECU 20 ends the process of the flowchart of FIG.

  On the other hand, when the determination in step S8 is “NO” (when the required torque A is greater than the discharge determination torque β), the ECU 20 sets a target engine operating point (target engine torque) and a target motor torque in step S10. To do.

  Specifically, the ECU 20 sets the target engine operating point (target engine torque) to a value equal to the discharge determination torque β.

  Here, the difference between the target engine torque and the required torque A is set as the target motor torque. Specifically, when the required torque A is larger than the discharge determination torque β, that is, when the target engine torque is set to a value equal to the discharge determination torque β, the ECU 20 determines that the required torque and the target engine torque are A−β. The difference is set as the target motor torque, and the operation of the motor 3 is controlled. At this time, since the required torque A is larger than the discharge determination torque β, the ECU 20 operates the engine 2 with a target engine torque β that is smaller than the driver's required torque A, but is insufficient with respect to the driver's required torque A. The engine torque is compensated by the operation of the motor 3. In this way, since the engine 2 is operated at a heat efficient operating point, fuel efficiency can be improved, and the engine torque that is insufficient with respect to the driver's required torque is compensated by operating the motor 3, so that Can be used efficiently. Further, the ECU 20 calculates the discharge determination torque β according to the SOC and sets the target engine torque based on the relationship between the discharge determination torque β and the driver's required torque A, so that the fuel efficiency improvement effect is not impaired. Overcharging of the battery 11 can be prevented.

  Here, in the drive control system according to the present embodiment, the target motor torque is the difference between the required torque A and the target engine torque. Therefore, when the torque of the motor 3 during power running is a positive value B, the target motor torque The relationship of engine torque = A−B is established. Therefore, in step S10, the ECU 20 sets the target motor torque to a positive value B that is the torque of the motor 3 during power running. In this way, the motor 3 generates a power running torque that is the difference between the required torque A and the target engine torque, and assists the engine 2. Thereafter, the ECU 20 ends the process of the flowchart of FIG.

  Next, the results of the engine operating point determination process when the SOC is 60%, 40%, and 80% will be described by applying specific numerical values. Note that 60%, 40%, and 80% of the SOC are an intermediate value, a lower limit value, and an upper limit value of the SOC management range in the present embodiment.

(When SOC is 60%)
When the SOC is 60% of the intermediate value of the management range, the determination torque map is as shown in FIG. 8, FIG. 9, and FIG. 8, 9, and 10, the power generation determination torque α and the discharge determination torque β when the engine speed is 4000 rpm are 50 N and 90 N, respectively.

  As shown in FIG. 8, when the required torque A of the driver when the engine speed is 4000 rpm is 30 N, the required torque A is smaller than the power generation determination torque α, so the ECU 20 determines the engine operating point as the power generation determination torque. Set to α. Then, the ECU 20 operates the engine with a target engine torque (50 N) equal to the power generation determination torque α.

  Further, the ECU 20 operates the motor 3 with −20N that is the difference between the target engine torque and the required torque A as the target motor torque. That is, the ECU 20 causes the motor 3 to generate power using the surplus engine torque (20N) with respect to the required torque A.

  As shown in FIG. 9, when the required torque A when the engine speed is 4000 rpm is 120 N, the required torque A is larger than the discharge determination torque β, so the ECU 20 sets the engine operating point to the discharge determination torque β. Set. Then, the ECU 20 operates the engine with a target engine torque (90 N) equal to the discharge determination torque β.

  Further, the ECU 20 operates the motor 3 with 30N, which is the difference between the target engine torque and the required torque A, as the target motor torque. In other words, the ECU 20 supplements the insufficient torque (30N) with respect to the required torque A by the power running torque of the motor 3.

  As shown in FIG. 10, when the required torque A when the engine speed is 4000 rpm is 80 N, the required torque A is not less than the power generation determination torque α and not more than the discharge determination torque β. The engine 2 is operated with the required torque A as the target engine torque, and the motor 3 is not operated.

  As described above, in any of FIGS. 8, 9, and 10, the ECU 20 operates the engine so that the engine operating point (target engine torque) enters the region sandwiched between the power generation determination torque α and the discharge determination torque β. A point is set. Thereby, appropriate discharge and charge can be performed without impairing the fuel efficiency improvement effect. The above operation is executed not only when the SOC is 60% but also when the SOC is in the range of 40% to 80%.

(When SOC is 40%)
When the SOC is 40% of the lower limit value of the management range, the discharge determination torque β is set to 200 N, which is a very high value, regardless of the engine speed, as shown in FIGS.

  As a result, the required torque A does not become larger than the discharge determination torque β. Therefore, when the required torque A is equal to or greater than the power generation determination torque α, the ECU 20 operates the engine 2 with the required torque A as the target engine torque, and the motor 3 Does not work.

  On the other hand, the power generation determination torque α when the SOC is 40% is set to a value larger than the power generation determination torque α when the SOC is 60% as shown in FIGS. For this reason, the engine torque allocated to the power generation by the motor 3 is increased, and the power generation is promoted.

  Thus, when the SOC of the battery 11 is the lower limit value of the management range, the ECU 20 operates the engine 2 with the driver's required torque A and operates the motor 3 if the driver's required torque A is equal to or greater than the power generation determination torque α. Does not work. On the other hand, if the driver's required torque A is smaller than the power generation determination torque α, the target engine torque is set equal to the power generation determination torque α, and the difference between the target engine torque and the driver's required torque A is set as the target motor torque. Electric power is generated by the motor 3. Thereby, the overdischarge of the battery 11 is prevented.

  As described above, when the SOC is 40%, the ECU 20 sets the target engine torque and the target motor torque so that the power running torque is not output from the motor 3 and power generation by the motor 3 is promoted. Even when the SOC is smaller than 40% due to an electrical load other than the motor 3, the ECU 20 performs the same control as described above.

(When SOC is 80%)
When the SOC is 80% of the upper limit value of the management range, the power generation determination torque α is set to 0N, which is a very small value, regardless of the engine speed, as shown in FIGS.

  As a result, the required torque A does not become smaller than the power generation determination torque α. Therefore, when the required torque A is equal to or less than the discharge determination torque β, the ECU 20 operates the engine 2 with the required torque A as the target engine torque, and the motor 3 Does not work.

  On the other hand, the discharge determination torque β when the SOC is 80% is set to a value smaller than the discharge determination torque β when the SOC is 60%, as shown in FIGS. That is, the discharge of the battery 11 is promoted by the motor assist.

  Thus, when the SOC of the battery 11 is the upper limit value of the management range, the ECU 20 operates the engine 2 with the driver's required torque A and the motor 3 if the driver's required torque A is equal to or less than the discharge determination torque β. Does not work. On the other hand, if the driver's required torque A is larger than the discharge determination torque β, the target engine torque is set equal to the discharge determination torque β, and the difference between the target engine torque and the driver's required torque A is set as the target motor torque. The motor 3 is operated and discharge is performed. Thereby, overcharge of the battery 11 is prevented.

  As described above, when the SOC is 80%, the ECU 20 generates the target engine torque and the target motor torque so that the motor 3 does not generate power and the discharge of the battery 11 due to the power running of the motor 3 is promoted. Set. Even when the SOC is greater than 80% due to an electrical load other than the motor 3, the ECU 20 performs the same control as described above.

  The effects of the drive control system of the present embodiment described above will be described.

  In the drive control system of the present embodiment, the determination torque calculation unit 23 calculates a determination torque obtained based on the engine torque when the engine 2 is operated at an operating point with good thermal efficiency according to the SOC of the battery 11. Then, the operation control unit 24 operates the engine 2 and the motor 3 with the target engine torque and the target motor torque obtained based on the relationship between the driver's required torque A and the determination torque.

  From such a configuration, the determination torque (power generation determination torque α and discharge determination torque β) used when determining the target engine torque and the target motor torque is the engine torque (thermal efficiency) when the engine is operated at a thermal efficiency operating point. In addition, a determination torque corresponding to the SOC of the battery 11 is calculated. Since the operation of the engine and the motor is controlled using the determination torque calculated in this manner, it is possible to manage an appropriate SOC of the battery without impairing the fuel efficiency improvement effect.

  In the drive control system of the present embodiment, the determination torque calculation unit 23 calculates the power generation determination torque α during power generation according to the SOC of the battery 11.

  When the required torque A is smaller than the power generation determination torque α, the operation control unit 24 operates the engine 2 using the power generation determination torque α as the target engine torque, and determines the difference between the target engine torque and the required torque A as the target motor torque. The motor 3 is operated as follows.

  With this configuration, as shown in FIG. 11, when the required torque A is smaller than the power generation determination torque α, the engine 2 is operated with the power generation determination torque α as the target engine torque.

  That is, as shown in FIG. 11, when the required torque A is in the operating point correction region below the power generation determination torque α, the target engine operating point is corrected to be pulled up to the torque line of the power generation determination torque α. For this reason, fuel consumption can be improved.

  Further, by setting the difference between the target engine torque and the required torque A as the target motor torque, the motor 3 is operated so as to generate power generation torque. For this reason, the electric power generated by the motor 3 is charged in the battery 11, and overdischarge of the battery 11 can be prevented.

  Further, since the power generation determination torque α is calculated according to the SOC of the battery 11, it is possible to achieve both improvement in fuel efficiency and prevention of overdischarge of the battery 11. As a result, the SOC of the battery can be managed while improving the fuel efficiency.

  In the drive control system of the present embodiment, the determination torque calculation unit 23 calculates the discharge determination torque β during discharge according to the SOC of the battery 11.

  When the required torque A is greater than the discharge determination torque β, the operation control unit 24 operates the engine 2 using the discharge determination torque β as the target engine torque, and calculates the difference between the target engine torque and the required torque A as the target motor torque. The motor 3 is operated as follows.

  With this configuration, as shown in FIG. 11, when the required torque A is larger than the discharge determination torque β, the engine 2 is operated with the discharge determination torque β as the target engine torque.

  That is, as shown in FIG. 11, when the required torque A is in the operating point correction region above the discharge determination torque β, the target engine operating point is corrected to be lowered to the torque line of the discharge determination torque β. For this reason, fuel consumption can be improved.

  Further, by setting the difference between the target engine torque and the required torque A as the target motor torque, the motor 3 is operated so as to generate power generation torque. For this reason, the battery 11 is discharged by the power running of the motor 3, and the overcharge of the battery 11 can be prevented.

  In addition, since the discharge determination torque β is calculated according to the SOC of the battery 11, it is possible to achieve both improvement in fuel efficiency and prevention of overcharge of the battery 11. As a result, the SOC of the battery 11 can be managed while improving fuel efficiency.

  In the drive control system of the present embodiment, the determination torque calculation unit 23 calculates the power generation determination torque α during power generation and the discharge determination torque β during discharge according to the SOC of the battery 11.

  Then, when the required torque A is equal to or greater than the power generation determination torque α and the required torque A is equal to or less than the discharge determination torque β, the operation control unit 24 operates the engine 2 with the required torque A as the target engine torque, and the motor 3 Does not work.

  With this configuration, as shown in FIG. 11, when the required torque A is equal to or greater than the power generation determination torque α and the required torque A is equal to or less than the discharge determination torque β, the engine 2 is operated with the required torque A as the target engine torque. The

  That is, as shown in FIG. 11, when the required torque A is below the discharge determination torque β and above the power generation determination torque α, the target engine operating point is set equal to the required torque A. The motor torque of the motor 3 becomes zero. As a result, the SOC of the battery 11 can be managed while improving fuel efficiency.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

  For example, the SOC management range is not limited to 40% to 80%. Further, the values in the determination torque map, the power generation determination torque map, and the discharge determination torque map are examples, and these values differ depending on what balance it is desired to achieve both fuel efficiency improvement and SOC management. When priority is given to improving the fuel efficiency, it is preferable that the torque lines of the power generation determination torque α and the discharge determination torque β be close to the optimum thermal efficiency line. Also, the optimum value in each map differs depending on whether the assumed running pattern is mainly urban running or high-speed running.

2 Engine 3 Motor 11 Battery 16 Accelerator operation amount detector 17 Engine speed detector 21 Required torque calculator 22 Remaining charge detector 23 Determination torque calculator 24 Operation controller

Claims (4)

In a drive control system that controls engine operation based on a target engine torque and controls motor operation based on a target motor torque,
An accelerator operation amount detector for detecting an accelerator operation amount;
An engine speed detector for detecting the engine speed;
A required torque calculation unit that calculates a driver's required torque based on the accelerator operation amount and the engine speed;
A remaining charge detection unit for detecting the remaining charge of the battery;
A determination torque calculation unit that calculates a determination torque obtained based on an engine torque when the engine is operated at a thermal efficient operating point according to a remaining charge of the battery;
A drive control system comprising: an operation control unit that controls operations of the engine and the motor based on a target engine torque and a target motor torque obtained based on a relationship between the required torque and the determination torque. The determination torque calculation unit calculates a power generation determination torque during power generation according to a remaining charge of the battery,
The operation controller is
When the required torque is smaller than the power generation determination torque, the engine is operated with the power generation determination torque as a target engine torque,
The drive control system according to claim 1, wherein the motor is operated with a difference between the target engine torque and the required torque as a target motor torque. The determination torque calculation unit calculates a discharge determination torque at the time of discharging according to a remaining charge of the battery,
The operation controller is
When the required torque is greater than the discharge determination torque, the engine is operated with the discharge determination torque as a target engine torque,
The drive control system according to claim 1 or 2, wherein the motor is operated with a difference between the target engine torque and the required torque as a target motor torque. The determination torque calculation unit calculates a power generation determination torque during power generation and a discharge determination torque during discharge according to the remaining charge of the battery,
The operation controller is
When the required torque is equal to or greater than the power generation determination torque and the required torque is equal to or less than the discharge determination torque, control is performed so that the engine is operated with the required torque as a target engine torque and the motor is not operated. The drive control system according to any one of claims 1 to 3, wherein:

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