Control Method of Vehicle and Vehicle

Abstract

A control method for a vehicle, wherein the vehicle has: a first mode that performs braking force compensation based on a friction brake during regeneration based on a drive motor in a state without an accelerator operation, i.e., during regeneration when the accelerator is off; and a second mode that does not perform braking force compensation based on a friction brake during regeneration when the accelerator is off. The control method for the vehicle includes: performing input restriction on a storage battery; and making the SOC at which the input power to the storage battery becomes zero due to the input restriction different between the first mode and the second mode.

Description

Technical Field

[0001] The present invention relates to a control method for a vehicle and a vehicle. Background Art

[0002] In Japanese Patent JP5712999B, the following technique is disclosed for suppressing overcharging by consuming battery power through forced rotation of an engine based on an electric motor together with regenerative braking. That is, it is disclosed that in motor driving priority, when the regenerative power of the motor exceeds the maximum charging power, i.e., the over-generating power, the rotation of the engine in the operation stop state is restricted more than when it is not over-generating power, and the motor is regeneratively driven within the maximum charging power range.

[0003] When the engine is electrically driven by a generator, noise is generated, and the electric drive is not preferred by the occupants in order to suppress overcharging of the battery and the like. As a result, the occupants may feel discomfort due to the electric drive noise, that is, the noise generated by the electric drive. Summary of the Invention

[0004] The present invention has been made in view of such problems, and an object thereof is to improve the discomfort caused to the occupants by the electric drive noise.

[0005] In a control method for a vehicle according to an aspect of the present invention, the vehicle has: a first mode in which, during regeneration based on a drive motor in a state without an accelerator operation, i.e., during regeneration when the accelerator is off, braking force compensation based on a friction brake is performed; and a second mode in which braking force compensation based on a friction brake is not performed during regeneration when the accelerator is off. The control method for the vehicle includes: performing input restriction on the battery; and making the voltage of the battery for which the input power to the battery becomes zero due to the input restriction or a physical parameter of the battery that affects the voltage different between the first mode and the second mode.

[0006] According to another aspect of the present invention, there is provided a control device for a vehicle corresponding to the above-described control method for a vehicle. Brief Description of the Drawings

[0007] Figure 1 It is a diagram showing a schematic configuration diagram of a vehicle.

[0008] Figure 2 It is an explanatory diagram of a shift position and a drive mode.

[0009] Figure 3 It is a first diagram for explaining friction brake compensation.

[0010] Figure 4 It is a second diagram for explaining friction brake compensation.

[0011] Figure 5 It is a block diagram showing the processing of the vehicle controller.

[0012] Figure 6 It is a diagram showing an example of the battery charging characteristics.

[0013] Figure 7 It is a diagram showing an example of the selection process of the battery charging characteristics represented by a flowchart.

[0014] Figure 8 It is a diagram showing an example of the setting of the switching rate corresponding to the vehicle speed.

[0015] Figure 9 It is a block diagram showing the discharge request process.

[0016] Figure 10 It is a diagram showing an example of the setting process of the discharge start SOC represented by a flowchart.

[0017] Figure 11 It is a diagram showing an example of the setting process of the discharge enable flag represented by a flowchart.

[0018] Figure 12 It is a diagram showing the first example of the timing diagram.

[0019] Figure 13 It is a diagram showing the second example of the timing diagram.

[0020] Figure 14 It is a diagram showing the third example of the timing diagram.

[0021] Figure 15 It is a diagram showing the fourth example of the timing diagram. Detailed implementation mode

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] Figure 1 It is a diagram showing a schematic structural diagram of the vehicle 100. The vehicle 100 includes: an engine 1, a generator 2, a drive motor 3, a gear 4, drive wheels 5, a battery 6, and a braking system 7. The vehicle 100 is a series hybrid vehicle and has a series hybrid mode as a driving mode. When the driving mode is the series hybrid mode, the vehicle 100 drives the generator 2 by the engine 1 to generate electricity, and drives the drive motor 3 with the electricity generated by the generator 2.

[0024] The engine 1 is an internal combustion engine and is configured as a gasoline engine. The engine 1 is connected to the generator 2 in a power-transmittable manner. The generator 2 is a motor generator for power generation and, in addition to power generation, also performs electric drive of the engine 1. The electric drive is performed by driving the engine 1 in a rotationally stopped state with the generator 2. The drive motor 3 is a motor generator for driving and generates the driving force of the vehicle 100. The driving force generated by the drive motor 3 is transmitted to the drive wheels 5 via a reduction gear, i.e., the gear 4. The drive motor 3 is also driven by the power from the drive wheels 5 and performs energy regeneration. The drive motor 3 can charge the regenerated energy as electric power into the storage battery 6.

[0025] The storage battery 6 stores the electric power generated by the generator 2 and the electric power regenerated by the drive motor 3. A discharge start SOC (State Of Charge) is set for the storage battery 6. The SOC is an example of a physical parameter of the storage battery 6 that affects the voltage of the storage battery 6 and indicates the charge state of the storage battery 6. The discharge start SOC is preset to a value for defining the full charge of the storage battery 6. In other words, the full charge of the storage battery 6 is defined by the discharge start SOC. For example, when the SOC as a charge rate is 90%, it is a full charge.

[0026] The braking system 7 includes: a friction brake 71, a brake actuator 72, a brake pedal 73, and a master cylinder 74. The friction brake 71 is provided on the drive wheels 5. The braking force of the friction brake 71 is controlled by the brake actuator 72. The brake actuator 72 controls the braking force based on the brake hydraulic pressure generated by converting the stepping force of the brake pedal 73 by the master cylinder 74.

[0027] The vehicle 100 further includes: a motor controller 10, an engine controller 20, a brake controller 30, and a vehicle controller 40. These controllers 10 to 40 are connected to be communicable with each other. The motor controller 10 is composed of one or more microcomputers including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The motor controller 10 performs various controls by causing the CPU to execute programs stored in the ROM or RAM. The same applies to the engine controller 20, the brake controller 30, and the vehicle controller 40.

[0028] The motor controller 10 controls the generator 2 and the drive motor 3. The motor controller 10 also includes a first inverter that is an inverter for the generator 2 and a second inverter that is an inverter for the drive motor 3. These inverters may also have a structure different from that of the motor controller 10. The motor controller 10 controls the generator 2 and the drive motor 3 by controlling the first inverter and the second inverter.

[0029] The first inverter is connected to the generator 2 and the battery 6. The first inverter converts the alternating current supplied from the generator 2 into direct current and supplies it to the battery 6. Thus, the electric power generated by the generator 2 is charged into the battery 6. The first inverter also converts the direct current supplied from the battery 6 into alternating current and supplies it to the generator 2. Thus, the generator 2 is driven by the electric power of the battery 6. The same applies to the second inverter, the drive motor 3, and the battery 6. Signals such as current, voltage, and SOC are also input from the generator 2, the drive motor 3, and the battery 6 to the motor controller 10.

[0030] The engine controller 20 controls the engine 1, and the brake controller 30 controls the braking system 7. The vehicle controller 40 comprehensively controls the engine 1, the generator 2, the drive motor 3, the braking system 7, etc. Signals from an accelerator opening sensor 61 for detecting the accelerator opening APO, a mode SW62 for selecting a drive mode by the driver's operation, a switching SW63 for switching the presence or absence of the friction brake compensation described later, and a shift position sensor 64 for detecting the shift position (gear position) selected by the driver's operation are input to the vehicle controller 40. A signal from a brake sensor 65 for detecting the brake hydraulic pressure is also input to the vehicle controller 40 via the brake controller 30. The vehicle controller 40, together with the motor controller 10, the engine controller 20, and the brake controller 30, constitutes a controller 50.

[0031] Figure 2 It is an explanatory diagram of the shift position and the drive mode. The vehicle 100 also has a shifter 9. The shifter 9 is a device for selecting a shift position by the driver's operation, and the driver's operation is performed by operating a shift lever and a switch on a gate corresponding to each shift position. The shifter 9 is considered an instantaneous shifter. In the instantaneous shifter 9, the shift lever released by the driver's operation automatically returns to the neutral position, i.e., the original position.

[0032] The gears selectable by the shifter 9 include, in addition to the P gear (parking gear), the R gear (reverse gear), and the N gear (neutral gear), the D gear as the first forward gear and the B gear as the second forward gear. The D gear and the B gear are selected by operating the shift lever on the common D / B gate. When the D gear has been selected, the B gear is selected by operating the shift lever on the D / B gate, and when the B gear has been selected, the D gear is selected. When a gear other than the D gear and the B gear is selected, the D gear is selected by operating the shift lever on the D / B gate.

[0033] The drive modes selectable via mode SW62 include the N mode, S mode, and ECO mode. The N mode is a mode of accelerating by operating the accelerator pedal (standard mode). Therefore, in the N mode, strong regenerative deceleration is not performed by operating the accelerator pedal. The S mode and ECO mode are modes of accelerating and performing regenerative deceleration by operating the accelerator pedal (one-pedal mode), and the ECO mode is a mode more suitable for fuel-cost driving than the S mode. The drive mode changes in the order of the N mode, S mode, and ECO mode each time mode SW62 is pressed, and returns to the N mode after the ECO mode.

[0034] In the S mode and ECO mode, deceleration is generated by regeneration by the drive motor 3. In other words, deceleration is negative acceleration and is represented by a negative value. The regeneration limit amount (the magnitude of the regeneration limit) is set larger in the S mode than in the ECO mode. In other words, regeneration in the S mode is not inhibited compared to the ECO mode. Therefore, the S mode obtains more electric power by regeneration than the ECO mode, and the magnitude of the generated deceleration is also larger.

[0035] The switching SW63 is used to select the first mode for performing friction brake compensation and the second mode for not performing friction brake compensation, and constitutes a selector for the driver to select the operation mode of the friction brake 71 regarding the presence or absence of friction brake compensation. The description of the friction brake compensation is as follows.

[0036] Figure 3 and Figure 4 are diagrams for explaining friction brake compensation using timing diagrams. Figure 3 represents the case of no friction brake compensation, Figure 4 represents the case of having friction brake compensation. Figure 3 、 Figure 4 both represent the changes in various parameters during regeneration based on the drive motor 3 when the accelerator is disengaged for regeneration, that is, in a state where there is no accelerator operation.

[0037] In these examples, by disengaging the accelerator for regeneration, the vehicle speed VSP is made constant, the accelerator opening APO and the brake pedal force are zero. In addition, since the brake pedal force is zero, the friction brake torque is zero. The vehicle speed VSP is constant because the acceleration and deceleration are in balance when going downhill. In these examples, at the beginning of the timing diagram, the target generated electric power is zero and the engine 1 is in the stopped state.

[0038] To compare and explain the differences in the presence or absence of friction brake compensation, the discharge start SOC and discharge end SOC are the same in Figure 3 and Figure 4 , and the changes up to time T3 are the same in Figure 3 and Figure 4 . Therefore, first, the following uses Figure 3The timing chart shown illustrates the changes up to time T3.

[0039] At time T1, the SOC becomes the end-of-discharge SOC. In these examples, the input limit start SOC for the battery 6 is set to the same value as the end-of-discharge SOC. The input limit for the battery 6, i.e., the limit on the input power to the battery 6, is carried out by gradually decreasing the regenerative power of the drive motor 3 in absolute value according to the rise of the SOC. The regenerative power is used to limit the regenerative power to a value below the regenerative power in absolute value. The input limit starts when the regenerative power and the regenerative power are equal, and does not start when the regenerative power is less than the regenerative power in absolute value. By starting such an input limit from time T1, the regenerative power gradually decreases in absolute value.

[0040] At time T1, the regeneration limit of the drive motor 3 also starts. The regeneration limit is carried out by gradually decreasing the regenerative torque of the drive motor 3 in absolute value according to the rise of the SOC. The regeneration limit starts when the regenerative torque and the regenerative torque are equal, and does not start when the regenerative torque is less than the regenerative torque in absolute value. The regenerative torque is used to limit the regenerative torque to a value below the regenerative torque in absolute value. By starting such a regeneration limit from time T1, the regenerative torque also gradually decreases in absolute value.

[0041] At time T1, the regenerative torque is less than the regenerative torque in absolute value. Therefore, the regeneration limit does not start, and the regenerative torque is controlled to the target torque. The target torque is calculated based on the vehicle speed VSP and the accelerator opening APO. The regenerative power obtained from the regenerative torque is also controlled to the target power like the regenerative torque.

[0042] At time T2, the SOC reaches the start-of-discharge SOC, and the target power generation power changes from zero to negative. Therefore, the electric drive of the engine 1 starts, and the battery 6 is discharged by the power consumption of the generator 2. As a result, the absolute values of the regenerative power and the regenerative torque increase. Compared with before time T2, the SOC slowly rises by the amount of discharge. After the regenerative power and the regenerative torque increase in absolute value to the magnitude corresponding to the target power generation power, they start to decrease again in absolute value.

[0043] At time T3, as a result of the regenerative power reaching the regenerative power, the input limit starts. When the input limit starts, the regenerative power is limited to the regenerative power. Similarly, at time T3, as a result of the regenerative torque reaching the regenerative torque, the regeneration limit of the drive motor 3 starts, and the regenerative torque is limited to the regenerative torque. When the regenerative torque is limited to the regenerative torque, the regenerative braking force decreases by an amount corresponding to the difference between the regenerative torque and the target torque.

[0044] In the case of no friction brake compensation, in order to ensure the braking force of the amount reduced due to the regeneration limit, brake operation is required. Therefore, in this example, by starting the brake operation from time T3, the brake pedal force is increased, and correspondingly, the friction brake torque is increased. That is, in the case of no friction brake compensation, when regeneration limit is performed, the driver needs to perform brake operation as needed to cope with the deceleration change caused by the regeneration limit.

[0045] In Figure 4 In the case of the friction brake compensation shown, the friction brake compensation is started from time T3. The friction brake compensation is based on the braking force compensation of the friction brake 71, and is a control for compensating the braking force of the amount reduced due to the regeneration limit with the braking force of the friction brake 71. Therefore, in this case, through the friction brake compensation, the friction brake torque is increased, and the braking force of the amount reduced due to the regeneration limit is compensated. As a result, in this case, even when the regeneration limit is performed, the deceleration is maintained, thus eliminating the trouble of the driver performing the brake operation.

[0046] Noise is generated when the engine 1 is electrically driven by the generator 2. The electric drive is for suppressing overcharging of the battery 6 and the like, and is not desirable for the occupants. As a result, the occupants may feel discomfort due to the electric drive noise.

[0047] In view of such a situation, in the present embodiment, the vehicle controller 40 is configured as follows.

[0048] Figure 5 It is a block diagram showing the processing of the vehicle controller 40. The vehicle controller 40 includes: a friction brake compensation determination unit 41, a regenerative power limit calculation unit 42, a target drive regenerative torque calculation unit 43, a deceleration torque distribution unit 44, and a power generation / discharge control calculation unit 45.

[0049] The friction brake compensation determination unit 41 determines whether there is a setting for friction brake compensation based on the input signal. A signal of the operation mode of the friction brake 71 and a signal of the drive gear are input to the friction brake compensation determination unit 41. The signal of the operation mode is used to determine which one of the first mode and the second mode is selected. The signal of the drive gear is used to determine whether the selected gear is a non-driving gear (P gear or N gear). In the case of a non-driving gear, since friction brake compensation is not required, it can be considered that there is no setting.

[0050] Therefore, when the second mode is selected or a non-driving gear is selected, it is determined that there is no friction brake compensation (setting of no friction brake compensation). On the other hand, when the first mode is selected and a gear other than the non-driving gear is selected, it is determined that there is friction brake compensation (setting of friction brake compensation). When it is determined that there is friction brake compensation, the compensation flag is set to ON, and when it is determined that there is no friction brake compensation, the compensation flag is set to OFF. The compensation flag is input from the friction brake compensation determination unit 41 to the regenerative power limit calculation unit 42 and the deceleration torque distribution unit 44.

[0051] The regenerative power limit calculation unit 42 includes: a first rechargeable power calculation unit 421, a second rechargeable power calculation unit 422, a rechargeable power selection unit 423, a switching rate processing unit 424, and a renewable torque calculation unit 425, and calculates the renewable torque. In other words, the renewable torque is the maximum regenerative torque that can be regenerated in the drive motor 3 with an absolute value upper limit.

[0052] The first rechargeable power calculation unit 421 calculates the regenerative power in the case of the first mode, and the second rechargeable power calculation unit 422 calculates the regenerative power in the case of the second mode. The SOC of the storage battery 6 is input to the first rechargeable power calculation unit 421 and the second rechargeable power calculation unit 422, and in these calculation units 421, 422, the regenerative power is calculated based on the input SOC respectively. The signal of the compensation flag is also input to the second rechargeable power calculation unit 422. In these calculation units 421, 422, the rechargeable power is calculated based on the storage battery charging characteristics described below respectively.

[0053] Figure 6 It is a diagram showing an example of the storage battery charging characteristics. The solid line represents the first charging characteristic C1, and the dashed line represents the second charging characteristic C2. For the sake of explanation, in Figure 6 the first charging characteristic C1 and the second charging characteristic C2 are shown in the same graph, but these characteristics C1, C2 can be defined by mutually different mapping data. The first charging characteristic C1 is applied to the first mode, and the second charging characteristic C2 is applied to the second mode. In the first charging characteristic C1 and the second charging characteristic C2, the rechargeable power of the storage battery 6 is preset according to the SOC respectively, and the charging of the storage battery 6 is performed so as not to exceed the rechargeable power. Therefore, the rechargeable power is, in other words, the inputtable power, and the input limit of the storage battery 6 can be represented by the rechargeable power. The rechargeable power is set for the regenerative power of the drive motor 3 corresponding to the magnitude of the renewable power.

[0054] Under the first charging characteristic C1, when the state of charge (SOC) is less than the first input limit start value α1, no input limit is imposed and the chargeable power is constant. On the other hand, when the SOC is equal to or greater than the first input limit start value α1, an input limit is imposed. The higher the SOC, the smaller the chargeable power is set. Furthermore, when the SOC is equal to or greater than the first zero limit value β1, which is higher than the first input limit start value α1, the chargeable power is zero. The first zero limit value β1 represents the zero limit value β of the input power to the battery 6 in the case where there is friction brake compensation.

[0055] Under the second charging characteristic C2, when the SOC is less than the second input limit start value α2, no input limit is imposed and the chargeable power is constant. On the other hand, when the SOC is equal to or greater than the second input limit start value α2, an input limit is imposed. The higher the SOC, the smaller the chargeable power is set. Furthermore, when the SOC is equal to or greater than the second zero limit value β2, which is higher than the second input limit start value α2, the chargeable power is zero. The second zero limit value β2 is the zero limit value β in the case where there is no friction brake compensation and is set to the SOC at the start of discharge. Therefore, in the SOC equal to or greater than the second zero limit value β2, the reduction of the SOC can be achieved by electric drive.

[0056] The first input limit start value α1 and the second input limit start value α2 are set to different values. In other words, in the first charging characteristic C1 and the second charging characteristic C2, the SOC at which the input limit starts is set to different values. Therefore, the first charging characteristic C1 and the second charging characteristic C2 make the SOC at which the input limit to the battery 6 starts different in the first mode in which the first charging characteristic C1 is applied and the second mode in which the second charging characteristic C2 is applied.

[0057] Similarly, the first zero limit value β1 and the second zero limit value β2 are set to different values. In other words, in the first charging characteristic C1 and the second charging characteristic C2, the SOC at which the chargeable power is zero is set to different values. Therefore, in the first charging characteristic C1 and the second charging characteristic C2, the SOC at which the input power to the battery 6 becomes zero due to the input limit is different in the first mode and the second mode.

[0058] The first input limit start value α1 is set to be less than the second input limit start value α2. Therefore, when the first mode is selected, the input limit starts at a lower SOC than when the second mode is selected. In addition, the first zero limit value β1 is set to be less than the second zero limit value β2. Therefore, when the first mode is selected, the input power to the battery 6 is limited to zero at a lower SOC than when the second mode is selected, thereby stopping regeneration. The first zero limit value β1 can also be set to be less than the second input limit start value α2. The pre-discharge start value γ will be described later.

[0059] In addition, in the present embodiment, as a simple method for managing the charge amount of the battery 6, the parameter for setting the charging characteristics is only the SOC. The control of the input / output power of the battery 6 is set to prevent overcharging of the battery 6, and the battery voltage (the voltage of the battery 6) is controlled within the normal use range through charge limitation and discharge control. The SOC is an index indicating the charge amount of the battery 6, and there is a tendency that the higher the SOC, the higher the battery voltage. Therefore, the charging power of the battery 6 is limited and the discharge is promoted as the SOC increases, thereby controlling the battery voltage to an appropriate voltage. In addition to the SOC, the parameters for preventing overcharging of the battery 6 include the battery voltage and the battery temperature (the temperature of the battery 6). By using at least one or more parameters including the SOC, the battery voltage can be controlled to prevent overcharging. Regarding the battery voltage, in order not to become an overvoltage due to the voltage rise caused by the resistance during charging, the charging power is set lower as the basic voltage (for example, the voltage when there is no load) is higher, thereby preventing overvoltage of the battery 6. Regarding the battery temperature, the lower the battery temperature, the higher the internal resistance value and the greater the voltage rise amount during charging. Therefore, the lower the battery temperature, the more the charging power of the battery 6 can be limited to prevent overvoltage.

[0060] Return to Figure 5 In the first rechargeable power calculation unit 421, the rechargeable power in the first mode is calculated by referring to the first charging characteristic C1 to calculate the rechargeable power. In the second rechargeable power calculation unit 422, the rechargeable power in the second mode is calculated by referring to the second charging characteristic C2 to calculate the rechargeable power. The rechargeable power calculated by the first rechargeable power calculation unit 421 is input to the rechargeable power selection unit 423. The rechargeable power calculated by the second rechargeable power calculation unit 422 is input to the rechargeable power selection unit 423 and the power generation / discharge control calculation unit 45.

[0061] The rechargeable power selection unit 423 selects the rechargeable power based on the input compensation flag. When the compensation flag is ON, the rechargeable power in the first mode is selected, and when it is OFF, the rechargeable power in the second mode is selected. In the rechargeable power selection unit 423, by selecting the rechargeable power, the selection of the battery charging characteristics corresponding to the setting of the presence or absence of friction brake compensation as shown below is performed.

[0062] Figure 7 FIG. is a diagram illustrating an example of the selection process of the battery charging characteristics performed by the vehicle controller 40 through a flowchart. The process of step S1 corresponds to the friction brake compensation determination unit 41, and the processes of step S2 and step S3 correspond to the rechargeable power selection unit 423. In step S1, it is determined whether there is friction brake compensation. If the determination in step S1 is affirmative, the process proceeds to step S2 and the first charging characteristic C1 is selected. That is, in the case of the presence of friction brake compensation, the first charging characteristic C1 is used as a reference for the calculation of the regenerative power limit. If the determination in step S1 is negative, the process proceeds to step S3 and the second charging characteristic C2 is selected. That is, in the case of the absence of friction brake compensation, the second charging characteristic C2 is used as a reference for the calculation of the regenerative power limit. After steps S2 and S3, the process ends.

[0063] Return to Figure 5 The rechargeable power selected by the rechargeable power selection unit 423 is input to the switching rate processing unit 424. The switching rate processing unit 424 performs switching rate processing of the input limit. The switching rate is the rate of change of the input limit corresponding to time, and the rechargeable power is specified as the object as a reduction rate corresponding to time.

[0064] In the case of switching from the second mode to the first mode in the switching rate processing, the switching rate is applied to the rechargeable power in the second mode when the first mode is selected, and the rechargeable power is gradually reduced by changing the rechargeable power according to the switching rate. Moreover, when switching from the second mode to the first mode, the input limit obtained by changing the rechargeable power according to the switching rate in this way is used as the input limit to the battery 6. This is for the following reasons.

[0065] That is, use Figure 6For example, when the SOC is the second input limit start value α2, the input limit starts in the second mode. On the other hand, the rechargeable power has been limited in the first mode. Therefore, in this case, if the input limit in the second mode is directly switched to the input limit in the first mode, the regeneration is restricted due to the sharp decrease in the rechargeable power. As a result, the deceleration decreases sharply in absolute value, causing discomfort to the occupants. Therefore, when switching from the second mode to the first mode, the input limit obtained as described above is used as the input limit for the battery 6. The switching rate is further set as follows.

[0066] Figure 8 FIG. is an example of setting the switching rate corresponding to the vehicle speed VSP. The higher the vehicle speed VSP, the larger the switching rate is set. This is because, in order to limit the change in deceleration within a specified range, the slower the change in the regenerative power needs to be set for a lower vehicle speed with a higher motor torque sensitivity with respect to the change in the regenerative input power. From this perspective, the switching rate can be preset according to the vehicle speed VSP.

[0067] Return to Figure 5 The rechargeable power adopted in the switching rate processing unit 424 is input to the regenerative torque calculation unit 425. The regenerative torque calculation unit 425 calculates the regenerative torque based on the input rechargeable power. The regenerative torque is obtained by making the rechargeable power negative, that is, converting the regenerative power torque into the regenerative torque. The calculated regenerative torque is input to the deceleration torque distribution unit 44.

[0068] The target driving regenerative torque calculation unit 43 calculates the target driving torque based on the vehicle speed VSP and the accelerator opening APO. The target driving torque is preset according to the vehicle speed VSP and the accelerator opening APO. When the accelerator is off and regenerating, a negative target driving torque is calculated as the target regenerative torque. The calculated target regenerative torque is input to the deceleration torque distribution unit 44.

[0069] The deceleration torque distribution unit 44 distributes the input target regenerative torque into the target friction brake torque and the target regenerative torque processed by the deceleration torque distribution unit 44. When the compensation flag is ON and the absolute value of the input target regenerative torque is greater than the regenerative torque, the input target regenerative torque cannot be used for regeneration. Therefore, in this case, the regenerative torque is used as the processed target regenerative torque, and the target friction brake torque is the torque with a magnitude equal to the difference between the input target regenerative torque and the regenerative torque.

[0070] When the compensation flag is ON and the input target regeneration torque is less than or equal to the renewable torque in absolute value, the input target regeneration torque is used as the processed target regeneration torque, and the target friction brake torque is zero. The same applies when the compensation flag is OFF. The target friction brake torque is input from the deceleration torque distribution unit 44 to the brake controller 30, and the processed target regeneration torque is input to the drive control unit 11 of the motor controller 10. The drive control unit 11 controls the drive motor 3 based on the input target regeneration torque.

[0071] The power generation / discharge control arithmetic unit 45 includes a power generation / discharge permission determination unit 451 and a target operation point arithmetic unit 452, and performs arithmetic operations for power generation control in which the engine 1 drives the generator 2 to generate power and discharge control in which the generator 2 electrically drives the engine 1.

[0072] The power generation / discharge permission determination unit 451 sets the power generation / discharge permission flag based on the input signal. In addition to the rechargeable power in the second mode, a preheating request for the engine 1 and other power generation / discharge requests are input to the power generation / discharge permission determination unit 451. The preheating of the engine 1 is based on the engine water temperature and is performed, for example, for preheating the exhaust gas purification catalyst. Since the preheating request is accompanied by the drive of the generator 2, it is executed as a power generation request.

[0073] Other power generation / discharge requests include, for example, power generation requests and discharge requests based on the SOC for energy management of the battery 6. Such discharge requests include, for example, discharge requests for electric drive to suppress overcharging of the battery 6. Other power generation / discharge requirements also include power generation / discharge requirements that are independent of the SOC.

[0074] The power generation / discharge permission flag includes a power generation permission flag and a discharge permission flag. For example, when there is a preheating request, in order to activate the catalyst as soon as possible, the preheating request is prioritized and the power generation permission flag is set to ON. When other power generation / discharge requests are power generation / discharge requests corresponding to the SOC, the power generation permission flag or the discharge permission flag is set to ON. When there is no preheating request and other power generation / discharge requests, the power generation / discharge permission flag is set to OFF. The discharge requirement corresponding to the SOC is performed based on the set discharge start SOC as described below.

[0075] Figure 9 It is a block diagram showing the discharge request process. The vehicle controller 40 also includes a discharge request unit 46. The discharge request unit 46 includes a discharge start SOC setting unit 461 and a discharge request generation unit 462. Signals of the compensation flag and the drive gear are input to the discharge start SOC setting unit 461. In the discharge start SOC setting unit 461, the discharge start SOC is set as described below.

[0076] Figure 10 FIG. is a diagram illustrating an example of a process for setting the SOC at the start of discharge. In step S11, it is determined whether there is a friction brake compensation. In step S12, it is determined whether the vehicle is in the B gear position. When a negative determination is made in step S11 or step S12, the process proceeds to step S14, and the second zero limit value β2 is set as the SOC at the start of discharge. In step S14, the second zero limit value β2 is merely set as the SOC at the start of discharge, and it functions as the SOC at the start of discharge even when there is a friction brake compensation. The second zero limit value β2 is set from the viewpoint of suppressing overcharging of the battery 6. When affirmative determinations are made in both step S11 and step S12, the process proceeds to step S13, and the pre-discharge start value γ is set as the SOC at the start of discharge. Regarding the pre-discharge start value γ, it is described as follows. Figure 6 It is described as follows.

[0077] As Figure 6 shown, assume that the pre-discharge start value γ is a SOC lower than the second zero limit value β2, and the rechargeable power is not zero at the pre-discharge start value γ. By starting the discharge with a SOC where the pre-discharge start value γ is lower than the second zero limit value β2, a pre-electric drive start-of-discharge SOC is configured with a larger margin of SOC compared to the case of starting the electric drive with the second zero limit value β2.

[0078] Assume that the pre-discharge start value γ is a SOC lower than the first zero limit value β1. Therefore, according to the pre-electric drive, the state of regeneration that cannot be performed when the rechargeable power becomes 0 can be continued for a longer time. The pre-discharge start value γ is set from the viewpoint of continuing regeneration (in other words, preventing the absolute value of the regeneration torque from decreasing). In this regard, from the viewpoint of suppressing overcharging, it is different from the second zero limit value β2 that is set as the start-of-discharge SOC for a SOC with zero rechargeable power. The pre-discharge start value γ is, for example, a SOC equal to or higher than the second input limit start value α2.

[0079] When the pre-discharge start value γ is set, the pre-discharge start value γ functions as the start-of-discharge SOC. Therefore, in this case, the second zero limit value β2 does not function as the start-of-discharge SOC. Even when the pre-discharge start value γ is set, the input limit with reference to the second charging characteristic C2 is performed. That is, the pre-discharge start value γ is merely a setting regarding discharge, and for the sake of explanation, it is merely shown together with the pre-discharge start value γ in Figure 6 . Therefore, the pre-discharge start value γ is not particularly reflected in the calculation of the regeneration control. The same applies to the second zero limit value β2 that is the start-of-discharge SOC.

[0080] Return to Figure 9, the set discharge start SOC is input to the discharge request generation unit 462. The SOC is also input to the discharge request generation unit 462, and when the SOC reaches or exceeds the input discharge start SOC, a discharge request is generated. When the input discharge start SOC is the second zero limit value β2, a discharge request corresponding to the second zero limit value β2 is generated as the discharge request. When the input discharge start SOC is the pre-discharge start value γ, a discharge request corresponding to the pre-discharge start value γ is generated as the discharge request. The discharge request is input to the power generation / discharge permission determination unit 451 as other power generation / discharge requests. In this case, the discharge permission flag is set as follows in the power generation / discharge permission determination unit 451.

[0081] Figure 11 FIG. is a diagram showing an example of the process of setting the discharge permission flag performed by the vehicle controller 40 in a flowchart. In step S21, it is determined whether there is a discharge request corresponding to the SOC. If the determination in step S21 is negative, the process ends. If the determination in step S21 is positive, the process proceeds to step S22. In step S22, it is determined whether there is a friction brake compensation. If the determination in step S22 is positive, the process proceeds to step S23, and it is determined whether the SOC is equal to or greater than the second zero limit value β2. That is, in the case of having a friction brake compensation, electric drive is performed from the viewpoint of suppressing overcharging of the battery 6, so the second zero limit value β2 is used as the comparison object for the SOC.

[0082] If the determination in step S23 is positive, the discharge permission flag is set to ON in step S24, and electric drive is permitted. If the determination in step S23 is negative, the discharge permission flag is set to OFF in step S25. Even if the discharge permission flag becomes OFF, the electric drive continues until the SOC becomes less than the discharge end SOC. After step S24 or step S25, the process ends.

[0083] In the case where the determination in step S22 is negative, the process proceeds to step S26, and it is determined whether the SOC is equal to or greater than the pre-discharge start value γ. That is, in the case of having no friction brake compensation, electric drive is performed from the viewpoint of continuing regeneration, so the pre-discharge start value γ is used as the comparison object for the SOC. If the determination in step S26 is positive, the discharge permission flag is set to ON. If the determination in step S26 is negative, the discharge permission flag is set to OFF. After step S27 or step S28, the process ends.

[0084] Return to Figure 5, the power generation / discharge permission flag is input from the power generation / discharge permission determination unit 451 to the target operation point calculation unit 452. The target operation point calculation unit 452 calculates the target operation point of the engine 1. When the power generation / discharge permission flag is ON, the target operation point is calculated based on the preheating request or other power generation / discharge requests. As the target operation point, the target torque and the target rotational speed are calculated. The calculated target torque and target rotational speed are input to the power generation / discharge system SYS. The power generation / discharge permission flag is also input from the power generation / discharge permission determination unit 451 to the power generation / discharge system SYS.

[0085] The power generation / discharge system SYS performs the power generation operation or the electric drive of the engine 1 when the power generation / discharge permission flag is ON. When the power generation permission flag is ON, the power generation operation is performed, and when the discharge permission flag is ON, the electric drive is performed. The power generation / discharge system SYS includes a motor controller 10 and an engine controller 20. The target rotational speed is input to the motor controller 10, and the target torque is input to the engine controller 20 respectively. The power generation / discharge permission flag is input to the motor controller 10 and the engine controller 20 respectively.

[0086] During the power generation operation, the engine 1 generates a target torque matching the target generated power, and the generator 2 generates a torque offsetting the generated torque of the engine 1 in order to reach the target rotational speed matching the target generated power. During the electric drive, the generator 2 is driven at the target rotational speed, and discharge is performed by consuming power by the generator 2. When the power generation / discharge permission flag is OFF, the power generation operation and the electric drive are prohibited.

[0087] The power generation / discharge control calculation unit 45 constitutes a power generation / discharge power control unit that performs power generation / discharge power control for controlling the generated power of the generator 2 and the discharge power of the electric drive based on the engine 1. The power generation / discharge control calculation unit 45 can be regarded as two calculation units, namely a power generation control calculation unit and a discharge control calculation unit, and it can be understood that a power generation power control unit and a discharge power control unit are formed in the power generation / discharge control calculation unit 45. The friction brake compensation determination unit 41, the regenerative power limit calculation unit 42, the target drive regenerative torque calculation unit 43, and the deceleration torque distribution unit 44 constitute a regenerative power control unit RG that performs regenerative power control for controlling the regenerative power of the drive motor 3.

[0088] Figure 12 is a diagram showing a first example of a timing chart corresponding to the control of the present embodiment. Figure 12 shows the changes in the case of friction brake compensation, that is, in the first mode. Figure 12 shows the changes in various parameters during accelerator-off regeneration. The same also applies to the following Figures 13 to 15 .

[0089] At time T11, the SOC exceeds the first input limit start value α1, and the input limit for the battery 6 starts. As a result, the first renewable power and the renewable torque start to decrease in absolute value. The first renewable power represents the renewable power in the case where the friction brake compensation is available. The regenerative torque is controlled to be less than the target torque of the renewable torque in absolute value and is not limited to the renewable torque. The same applies to the first renewable power. Since the first input limit start value α1 is lower than the second input limit start value α2, the input limit starts earlier compared to the case without friction brake compensation.

[0090] At time T12, the first renewable power reaches the target power and the renewable torque reaches the target torque, and the input limit and the regeneration limit are started. As a result, the regenerative power is limited to the first renewable power, and the regenerative torque is limited to the renewable torque. After starting the regeneration limit, corresponding to the amount by which the regenerative torque decreases in absolute value, there is a shortage of deceleration with respect to the target torque. Therefore, at time T12, the friction brake compensation also starts and the friction brake torque starts to increase.

[0091] At time T13, the first renewable power and the renewable torque become zero, and the SOC becomes equal to or higher than the first zero limit value β1. As a result, starting from time T13, since the power input to the battery 6 is limited to zero, the regeneration stops. Therefore, the first renewable power and the renewable torque remain zero, and the SOC remains at the first zero limit value β1.

[0092] Since the first zero limit value β1 is lower than the second zero limit value β2, at time T13, there is a margin in the power reception of the battery 6 compared to the case without friction brake compensation. Therefore, in this example, since the electric drive does not start at time T13, the discomfort caused by the electric drive noise to the occupants is prevented.

[0093] The change rate of the first renewable power corresponding to the SOC in the case where the friction brake compensation is available (the change rate during the start of the regeneration limit between time T12 and time T13) is set to be slower than the response rate of the friction brake torque. As a result, in this example, the friction brake torque compensates for the braking force corresponding to the amount by which the regenerative torque decreases in absolute value with respect to the target torque.

[0094] As a result of the friction brake compensation being delayed with respect to the progress speed of the regeneration limit, the occurrence of a shortage of deceleration with respect to the target torque can be prevented. The friction brake torque can also be the target magnitude to be compensated at time T13. This change rate setting can be performed by setting the limit degree of the input limit in the first mode set in such a way that the higher the SOC, the greater the limit degree.

[0095] Figure 13 This is a second example of a timing chart corresponding to the control of the present embodiment. Similar to Figure 12 the first example shown, Figure 13 it shows a case where friction brake compensation is present. The changes before time T23 are the same as Figure 12 the changes before time T13 in the first example shown. Therefore, the situation after time T23 will be described below.

[0096] In this example, after the input power to the battery 6 is limited to zero at time T23 to stop regeneration, a catalyst preheating request is made as a preheating request at time T24 during the zero input limit. However, the input limit applies to regenerative power control and not to power generation control. That is, the input limit does not affect the catalyst preheating request as a power generation request. Therefore, at time T24, the positive target power generation is calculated based on the catalyst preheating request, and the engine 1 performs a power generation operation corresponding to the target power generation.

[0097] Thereby, even during the input limit of the power to the battery 6, the catalyst can be preheated by preferentially generating power, suppressing the deterioration of exhaust emissions. In addition, at time T24, the SOC is lower than the second zero limit value β2, and there is a margin in the power reception of the battery 6, so there is no particular obstacle during the execution of the power generation operation.

[0098] Figure 14 This is a third example of a timing chart corresponding to the control of the present embodiment. In this example, the case of selecting the first mode from the second mode in the state where the B gear is selected is described. The second regenerative power represents the regenerative power without friction brake compensation. The regenerative torque represents the regenerative torque corresponding to the second regenerative power.

[0099] At time T31, the SOC becomes equal to or higher than the first input limit start value α1. As a result, the absolute value of the first regenerative power starts to decrease. However, since there is no friction brake compensation at time T31, the input limit and regeneration limit based on the first regenerative power are not performed. Therefore, the second regenerative torque does not change particularly.

[0100] At time T32, the SOC becomes equal to or higher than the second input limit start value α2. As a result, the input limit starts, and the absolute value of the second regenerative power starts to decrease. In addition, correspondingly, the absolute value of the second regenerative torque also starts to decrease.

[0101] At time T33, the SOC becomes equal to or greater than the pre-discharge start value γ. Since the B gear is selected without friction brake compensation at time T33, the discharge start SOC is set to the pre-discharge start value γ. Therefore, the target power generation power is calculated as a negative value and pre-electric drive is started. As a result, corresponding to the amount by which the renewable power increases in absolute value, the regeneration stop can be delayed and regeneration can continue further. After the target power generation power becomes constant at time T34, the renewable power and the renewable torque start to decrease again in absolute value as the SOC increases.

[0102] At time T35, the first mode is selected. Therefore, the renewable power becomes a state in which the first renewable power should be applied. However, the first renewable power has already decreased in absolute value compared to the target power at time T35. Therefore, when directly switching the renewable power from the second renewable power to the first renewable power, the result is that the regeneration torque changes sharply and the deceleration decreases sharply in absolute value.

[0103] Therefore, starting from time T35, the above switching rate is applied to the second renewable power when the first mode is selected, and the renewable power that changes according to the switching rate (the renewable power indicated by the double-dashed line) is used for input limitation instead of the first renewable power. Since the first mode is selected starting from time T35, the discharge start SOC and the discharge end SOC of the first mode are applied to the discharge start SOC and the discharge end SOC. As shown in the figure, the discharge start SOC of the first mode is set to the second zero limit value β2.

[0104] The discharge end SOC of the first mode is, for example, an SOC slightly lower than the first zero limit value β1, and the electric drive stops when the SOC is equal to or lower than the discharge end SOC. Starting from time T35, even if the second zero limit value β2 constitutes the discharge start SOC of the first mode, the electric drive continues to be maintained. When the SOC is higher than the discharge end SOC set in the first mode, the electric drive continues to be maintained until it reaches below the discharge end SOC of the first mode. To prevent control fluctuations, the discharge end SOC is set to be lower than the discharge start SOC by a specified magnitude.

[0105] Starting from time T36, the regenerative power is restricted to the renewable power that changes according to the switching rate and gradually decreases in absolute value. Correspondingly, the regeneration torque also gradually decreases in absolute value. Starting from time T36, the friction brake torque also starts to increase corresponding to the decrease in the regenerative power in absolute value. As a result, the braking force corresponding to the regeneration torque that decreases in absolute value with respect to the target torque is compensated.

[0106] At time T37, the renewable power that changes according to the switching rate becomes the first renewable power. As a result, from time T37, the regenerative power is limited by the first renewable power. The regenerative torque and the friction brake torque also become magnitudes corresponding to the regenerative power limited to the first renewable power.

[0107] In this example, slightly before time T37, the SOC becomes the first zero limit value β1, and the first renewable power and the regenerative power become zero. On the other hand, electric drive is in progress. Therefore, the SOC starts to decrease and becomes below the discharge end SOC of the first mode at time T37. As a result, the end condition of the electric drive is satisfied.

[0108] When the electric drive is stopped, correspondingly to the inability to consume power based on the electric drive, the second renewable power and the corresponding regenerative torque decrease in absolute value. Moreover, when the electric drive stops, the SOC does not change, so the second renewable power and the corresponding regenerative torque will remain constant.

[0109] The start determination and end determination of the electric drive are not limited to the SOC. For example, in addition to the voltage of the battery 6 and the power that can be input to the battery 6, which is a physical parameter of the battery 6 that affects the voltage, the regenerative request power and the discharge request power included in the input / output request to the battery 6 can also be used as determination elements, and the determination can be made based on one or more determination elements.

[0110] Figure 15 This is a diagram showing a fourth example of a timing chart corresponding to the control of the present embodiment. In this example, the case of selecting the first mode from the second mode in a state where the D gear is selected is described. At time T41, the SOC becomes equal to or higher than the first input limit start value α1. As a result, the first renewable power starts to decrease in absolute value. However, since there is no friction brake compensation at time T41, the regenerative torque does not change correspondingly.

[0111] At time T42, the first mode is selected, and the friction brake compensation changes from none to present. Therefore, as the renewable power, it becomes a state where the first renewable power should be applied. However, the first renewable power has already decreased significantly in absolute value compared to the case without friction brake compensation. Therefore, from time T42, the second renewable power at the time of selecting the first mode changes according to the switching rate, and this renewable power is used for input limitation instead of the first renewable power. As a result, at time T42, the regenerative power remains in a state of being controlled to the target power, and input limitation is not performed. Therefore, it is possible to prevent the deceleration from decreasing sharply in absolute value.

[0112] At time T43, the renewable power that changes according to the switching rate reaches the target power. Therefore, the regeneration limit of the drive motor 3 is started from time T43, and the regenerative torque that is controlled to the target torque is limited to the renewable torque. At time T43, in order to compensate for the braking force corresponding to the amount of the regenerative torque that decreases in absolute value due to the regeneration limit, the friction brake compensation is also started. As a result, the friction brake torque starts to rise. In this example, at time T43, the SOC reaches the first zero limit value β1, but since the renewable power that changes according to the switching rate is used for the input limit, the SOC continues to rise.

[0113] At time T44, the renewable torque becomes zero. Therefore, the regenerative torque becomes zero and the regeneration stops. At time T44, the friction brake torque generates a deceleration torque corresponding to the decrease in the regenerative torque caused by the limitation of the regenerative power, which is equivalent to the target regenerative torque. According to the switching rate characteristics described above with reference to Figure 8 The change speed of the renewable power according to the switching rate is slower than the response speed of the friction brake torque. As a result, the friction brake compensation follows the progress speed of the regeneration limit, and it is possible to prevent the occurrence of insufficient deceleration with respect to the target torque.

[0114] Next, the main effects of the present embodiment will be described.

[0115] The control method of the vehicle 100 of the present embodiment is for the vehicle 100, which includes: an engine 1, a generator 2, a drive motor 3, and a storage battery 6. The generator 2 is driven by the engine 1 to generate electricity, and the drive motor 3 is driven by the electricity generated by the generator 2, and the regenerative power of the drive motor 3 is supplied to the storage battery 6. The vehicle 100 has: a first mode in which braking force compensation based on the friction brake 71, that is, friction brake compensation, is performed when the accelerator is released and the regeneration is performed, and a second mode in which the friction brake compensation is not performed when the accelerator is released and the regeneration is performed. The control method of the vehicle 100 includes: performing an input limit on the storage battery 6 and making the SOC at which the input power to the storage battery 6 becomes zero different in the first mode and the second mode.

[0116] Here, in the case where there is no friction brake compensation, when the input power to the storage battery 6 is limited to zero, regeneration cannot be performed, and there will be insufficient deceleration with respect to the target torque. Therefore, in this case, in order to make up for the insufficient deceleration caused by the input limit to the storage battery 6, it is necessary to discharge using electric drive. That is, in order to make up for the insufficient deceleration by increasing the rechargeable power of the storage battery 6 through electric drive and performing corresponding regeneration, it is necessary to discharge through electric drive.

[0117] On the other hand, in the case of having friction brake compensation, even if regeneration cannot be performed, the insufficient regenerative torque can be compensated by the friction brake compensation. Therefore, in this case, the SOC that limits the input power to the battery 6 to zero does not need to be set extremely high within the range that will not cause overcharging. In addition, in such an SOC, since the power reception of the battery 6 still has a surplus, it is not necessarily required to perform discharge by electric drive.

[0118] Focusing on the above situation, according to the method of the present embodiment, the SOC that limits the input power to zero is made different in the first mode and the second mode. Therefore, even if the input power is limited to zero, electric drive can be not performed in the first mode. As a result, the discomfort caused to the occupants by the electric drive noise can be improved. In addition, according to such a method, the discomfort caused to the occupants due to insufficient deceleration generated according to the target torque can also be avoided.

[0119] The method of the present embodiment further includes starting the input restriction at a lower SOC when the first mode is selected than when the second mode is selected and stopping the regeneration of the drive motor 3. According to such a method, in the first mode, the input restriction is started earlier and the regeneration is stopped earlier than in the second mode. Therefore, the power reception of the battery 6 when the input power is zero can have a surplus. As a result, even if the input power is limited to zero, electric drive can be not performed in the first mode. Therefore, the discomfort caused to the occupants by the electric drive noise can be improved.

[0120] The method of the present embodiment further includes performing electric drive of the engine 1 by the generator 2, and when the first mode is selected, limiting the input power to the battery 6 to zero by input restriction before starting the electric drive. According to such a method, in the first mode, the electric drive is started after the input power to the battery 6 is limited to zero. Therefore, even if the input power is limited to zero, electric drive can be not performed, thereby improving the discomfort caused to the occupants by the electric drive noise.

[0121] The method of the present embodiment further includes performing regenerative power control for controlling the regenerative power of the drive motor 3 and performing power generation power control for controlling the power generation power of the generator 2. The input restriction is applicable to the regenerative power control and not applicable to the power generation power control. According to such a method, since power generation can be performed regardless of the input restriction, by preferentially improving the electric drive noise and performing power generation, the power generation requirements can be met. Therefore, for example, in the case of having a preheating request, the engine 1 can be operated according to the preheating request regardless of the input restriction, thereby avoiding the situation where preheating cannot be performed due to the input restriction.

[0122] The method of this embodiment further includes: electrically driving the engine 1 by the generator 2, and pre-electrically driving by electrically driving the engine 1 by the generator 2 at an SOC lower than that of the electric drive. When the first mode is selected, the execution of the pre-electric drive is prohibited. According to such a method, in the first mode, depending on the situation where the friction brake can be compensated at the time of regeneration stop, the execution of the pre-electric drive from the viewpoint of continuing regeneration is prohibited. Therefore, the discomfort caused to the occupants by the electric drive noise caused by the pre-electric drive can be improved.

[0123] The method of this embodiment further includes electrically driving the engine 1 by the generator 2. The regeneration of the drive motor 3 is stopped by limiting the input power to the battery 6 to zero. When the first mode is selected during the execution of the electric drive, even when the electric drive start condition of the first mode is not satisfied, that is, even when the SOC does not reach the discharge start SOC of the first mode, during the period when the electric drive end condition of the first mode is not satisfied, that is, during the period when the SOC does not reach the discharge end SOC of the first mode, the electric drive continues. According to such a method, in the first mode, when the electric drive should be performed according to the electric drive start condition and end condition of the first mode but the electric drive is already in progress, by preferentially discharging based on the electric drive, an early reduction of the SOC can be achieved.

[0124] In the method of this embodiment, as the change speed of the input limit with respect to the change in SOC, the change speed of the input limit performed in the first mode is set to be below the response speed of the brake torque for compensating the friction brake 71. In addition, the method of this embodiment sets the change speed of the input limit obtained by changing the input power at a switching rate, that is, the change speed of the renewable power at the switching rate, to be below the response speed of the brake torque for compensating the friction brake. According to these methods, since the regenerative torque of the part damaged by the regeneration limit can be appropriately compensated by the brake torque, the change in deceleration can be appropriately suppressed.

[0125] In the method of this embodiment, when switching from the second mode to the first mode, the switching rate is applied to the rechargeable power in the second mode when the first mode is selected, and the input limit obtained by changing the rechargeable power at the switching rate is used as the input limit to the battery 6. According to such a method, when switching from the second mode to the first mode, by immediately applying the input limit performed in the first mode, a situation where the deceleration changes sharply can be prevented.

[0126] As described above, the embodiments of the present invention have been described, but the above embodiments are only a part of the application examples of the present invention, and do not limit the technical scope of the present invention to the specific structures of the above embodiments.

Claims

1. A control method for a vehicle, the vehicle including an engine, a generator, a drive motor, and a storage battery, the generator being driven by the engine to generate electricity, the drive motor being driven by the electricity generated by the generator, and the regenerative electricity of the drive motor being supplied to the storage battery. Wherein, The vehicle has: a first mode, which performs braking force compensation based on a friction brake during regeneration of the drive motor in a state without an accelerator operation, that is, during regeneration when the accelerator is disengaged; A second mode, which does not perform braking force compensation based on the friction brake during regeneration when the accelerator is disengaged. The control method of this vehicle includes: Performing an input limit on the storage battery; Making the voltage of the storage battery or the physical parameter of the storage battery that affects the voltage, for which the input power to the storage battery becomes zero through the input limit, different in the first mode and the second mode.

2. The control method for a vehicle according to claim 1, Wherein, The physical parameter includes the SOC of the storage battery. When the first mode is selected, the start of the input limit and the stop of the regeneration of the drive motor are performed at a lower SOC than when the second mode is selected.

3. The control method for a vehicle according to claim 1, Wherein, It further includes: electrically driving the engine by the generator. When the first mode is selected, before starting the electric drive, the input power to the storage battery is limited to zero through the input limit.

4. The control method for a vehicle according to claim 1, Wherein, It further includes: Electrically driving the engine by the generator; Performing regenerative power control for controlling the regenerative power of the drive motor; Performing power generation power control for controlling the power generation power of the generator. The input limit is applicable to the regenerative power control and not applicable to the power generation power control.

5. The control method for a vehicle according to claim 1, Wherein, The physical parameter includes the SOC of the storage battery. The control method of this vehicle further includes: Electrically driving the engine by the generator; Performing pre-electric drive by electrically driving the engine by the generator at an SOC lower than the electric drive. When the first mode is selected, execution of the pre-electric drive is prohibited.

6. The control method for a vehicle according to claim 1, Wherein, It further includes: electrically driving the engine by the generator. The regeneration of the drive motor stops by limiting the input power to the storage battery to zero. When the first mode is selected during the execution of the electric drive, even when the start condition of the electric drive in the first mode is not satisfied, the electric drive continues during the period when the end condition of the electric drive in the first mode is not satisfied.

7. The control method for a vehicle according to claim 1, Wherein, The physical parameter includes the SOC of the storage battery. The rate of change of the input limit with respect to the change of the SOC is set to be below the response rate of the brake torque compensated by the friction brake for the rate of change of the input limit performed in the first mode.

8. The vehicle control method according to claim 1, wherein, in the case of transitioning from the second mode to the first mode, as the input limit, an input limit obtained by applying a rate of change to the inputtable power of the drive motor in the case of the second mode when the first mode is selected and changing the inputtable power at the rate of change is used.

9. The vehicle control method according to claim 8, wherein, the rate of change of the input limit obtained by changing the inputtable power at the rate of change is set to be below the response rate of the brake torque compensated by the friction brake.

10. A vehicle including an engine, a generator, a drive motor, and a storage battery, wherein the generator is driven by the engine to generate electricity, the drive motor is driven by the electricity generated by the generator, and the regenerative power of the drive motor is supplied to the storage battery, wherein, it has: a first mode in which, during regeneration based on the drive motor in a state without an accelerator operation, that is, during regeneration when the accelerator is off, braking force compensation based on a friction brake is performed; a second mode in which braking force compensation based on the friction brake is not performed during regeneration when the accelerator is off, and includes a controller that performs the input limit by making the voltage of the storage battery or a physical parameter of the storage battery that affects the voltage, for which the input power to the storage battery is zero due to the input limit to the storage battery, different between the first mode and the second mode.

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