JP6791808B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device for controlling a hybrid vehicle including an engine and a motor generator as a power source.

Conventionally, as in Patent Document 1, for example, a hybrid vehicle having an engine and a motor generator as a power source has been known. In such a hybrid vehicle, the battery and the motor generator are electrically connected via an inverter. Then, by driving the motor generator as a generator when the accelerator is off, the regenerative torque of the motor generator can be obtained as the braking torque while charging the battery.

Japanese Unexamined Patent Publication No. 2013-20663

By the way, the battery is provided with an upper limit voltage for the battery voltage for one purpose of protecting the battery. Therefore, charging of the battery is stopped when the battery voltage reaches the upper limit voltage. However, the battery has a characteristic that the battery voltage at the time of charging becomes higher than the open circuit voltage. Therefore, even if the battery voltage reaches the upper limit voltage during charging, there is a possibility that a large dissociation occurs between the open circuit voltage and the upper limit voltage. In particular, in a large vehicle such as a truck, the regenerative torque is larger than that of a general passenger car, so that the difference between the open circuit voltage and the battery voltage during charging tends to be large.

An object of the present invention is to provide a vehicle control device capable of effectively charging a battery when the accelerator is off.

The vehicle control device that solves the above problems is a vehicle control device mounted on a hybrid vehicle, and the hybrid vehicle has a clutch and an accelerator that connect and disconnect the rotation shaft of the engine and the rotation shaft of the motor generator. An auxiliary brake that increases the braking torque of the engine brake when off and has a first operating state in which a first torque is obtained and a second operating state in which a second torque larger than the first torque is obtained. The vehicle control device includes a voltage acquisition unit that acquires a battery voltage, a clutch engagement / disengagement, a regenerative torque of the motor generator, and a control unit that controls an operating state of the auxiliary brake. The control unit controls the clutch in the disengaged state, the regenerative torque in the second torque, and the auxiliary brake in the non-operating state, the clutch in the connected state, and the regenerative torque in the second state. It has a difference between the torque and the first torque, and a partial regenerative state that controls the auxiliary brake to the first operating state. When the battery voltage reaches the upper limit voltage in the regenerative state, the partial regenerative state is provided. Move to.

According to the above configuration, the second torque is embodied by the regenerative torque of the motor generator in the regenerative state, and the second torque is embodied by the first torque by the auxiliary brake and the regenerative torque by the motor generator in the partial regenerative state. As a result, even if the battery voltage reaches the upper limit voltage in the regenerated state, the battery can be charged in the partially regenerated state in which the increase width with respect to the open circuit voltage is smaller than that in the regenerated state. As a result, the battery can be effectively charged while obtaining a braking torque having the same magnitude as that of the auxiliary brake in the second operating state.

In the vehicle control device having the above configuration, the control unit has a non-regenerative state in which the clutch is connected, the regenerative torque is 0, and the auxiliary brake is controlled in the second operating state, and in the partial regenerative state. When the battery voltage reaches the upper limit voltage, it is preferable to shift to the non-regenerative state.

According to the above configuration, it is possible to prevent the battery voltage from exceeding the upper limit voltage while charging the battery to a higher charge rate.
In the vehicle control device having the above configuration, it is preferable that when the battery voltage reaches the upper limit voltage in the regenerative state, the control unit shifts to the partial regenerative state after the battery voltage drops to the open circuit voltage.

According to the above configuration, when the battery voltage reaches the upper limit voltage in the regenerative state, the battery voltage drops to the open circuit voltage and then shifts to the partial regenerative state. As a result, the battery voltage immediately after the transition to the partial regenerative state can be set to a voltage that is higher than the open circuit voltage at that time. As a result, the battery voltage immediately after the transition to the partial regenerative state becomes low, so that the battery can be charged more effectively.

In the vehicle control device having the above configuration, the hybrid vehicle is a switch in which the driver selects the braking torque obtained by the engine brake when the accelerator is off, and is a normal operation position when the auxiliary brake is in an inactive state. The vehicle control device includes the switch having a normal position indicating a normal torque which is a braking torque by an engine brake, a first position indicating the first torque, and a second position indicating the second torque, and the vehicle control device operates the operation. The control unit includes an operation position acquisition unit for acquiring a position, and the control unit has a second partial regeneration state in which the switch is in the second regenerative state to a second partial regeneration state in which the switch is in the second position. It is configured to shift to a state, and further, the clutch is connected to the first regenerative state in which the clutch is disengaged, the regenerative torque is controlled to the first torque, and the auxiliary brake is controlled to the non-operating state. It has a state, a difference between the first torque and the normal torque for the regenerative torque, and a first partial regenerative state for controlling the auxiliary brake to a non-operating state, and the switch is located at the first position. When the battery voltage reaches the upper limit voltage in the first regenerative state, the first partial regenerative state may be entered.

According to the above configuration, the battery can be effectively charged while obtaining the braking torque required by the driver.

The figure which shows the schematic structure of the hybrid vehicle which carries one Embodiment of a vehicle control device. A graph showing an example of the relationship between the charge rate and the battery voltage. The figure which shows an example of the relationship between the motor rotation speed and the braking torque schematically. A flowchart showing an example of normal processing. The flowchart which shows an example of the 1st braking process. The flowchart which shows an example of the 2nd braking process. The graph which shows an example of the transition of the battery voltage at the time of charging. A time chart showing an example of the relationship between switch operating position, clutch state, braking torque, regenerative torque, battery voltage, and charge rate. A time chart showing other examples of the relationship between switch operating position, clutch status, braking torque, regenerative torque, battery voltage, and charge rate. The figure which shows typically an example of the relationship between a motor rotation speed and a braking torque in a modification.

An embodiment of the vehicle control device will be described with reference to FIGS. 1 to 9.
The schematic configuration of the hybrid vehicle will be described with reference to FIG.
As shown in FIG. 1, the vehicle 10 which is a hybrid vehicle includes an engine 11 and a motor generator (hereinafter referred to as M / G) 12 as power sources. The rotating shaft 13 of the engine 11 and the rotating shaft 14 of the M / G 12 are connected to each other by a clutch 15 automatically controlled by a control device 30 which is a vehicle control device. The rotating shaft 14 of the M / G 12 is connected to the drive wheels 18 via the transmission 16 and the drive shaft 17.

The engine 11 is, for example, a diesel engine having a plurality of cylinders, and a torque for rotating the rotating shaft 13 is generated by burning fuel in each cylinder. The torque generated by the engine 11 is transmitted to the drive wheels 18 via the rotation shaft 14, the transmission 16, and the drive shaft 17 of the M / G 12 when the clutch 15 is in the connected state.

The engine 11 includes a retarder 11a as an auxiliary brake. The retarder 11a opens the exhaust valve when the piston reaches near top dead center in the compression stroke when the accelerator is off, discharges the working gas, and closes the exhaust valve in the expansion stroke immediately after the retarder 11a. Increase the braking torque of the engine brake. Similar to a normal engine brake, the retarder 11a generates a larger braking torque as the engine speed Ne increases.

The retarder 11a has a non-operating state, a first operating state, and a second operating state. The non-operating state is a state in which the compression / release operation is not performed in all of the plurality of cylinders, and the normal torque T0, which is the braking torque by the normal engine brake, is obtained. The first operating state is a state in which a first torque T1 which is a braking torque larger than the normal torque T0 can be obtained by performing a compression release operation in a part of a plurality of cylinders. The second operating state is a state in which a second torque T2, which is a braking torque larger than that of the first torque T1, is obtained by performing the compression release operation in all of the plurality of cylinders. The normal torque T0, the first torque T1, and the second torque T2 are obtained when the clutch 15 is in the connected state.

The M / G 12 is electrically connected to the battery 20 via the inverter 21. The battery 20 is a rechargeable and dischargeable secondary battery, and is composed of a plurality of cells electrically connected to each other. The M / G 12 functions as a motor that rotates the rotating shaft 14 by supplying the electric power stored in the battery 20 via the inverter 21. The drive torque generated when the M / G 12 functions as a motor is transmitted to the drive wheels 18 via the transmission 16 and the drive shaft 17. Further, the M / G 12 functions as a generator that stores the electric power generated by utilizing the rotation of the rotating shaft 14 when the accelerator is off, in the battery 20 via the inverter 21. The braking torque generated when the M / G 12 functions as a generator is called a regenerative torque Tr. The regenerative torque Tr can be controlled in a range equal to or less than the maximum regenerative torque Trmax set for each motor rotation speed Nm.

The transmission 16 shifts the drive torque of the rotating shaft 14 of the M / G 12, and transmits the changed torque to the drive wheels 18 via the drive shaft 17. The transmission 16 is configured so that a plurality of gear ratios Rt can be set.

When the M / G 12 functions as a motor, the inverter 21 converts the DC voltage from the battery 20 into an AC voltage to supply electric power to the M / G 12. Further, when the inverter 21 functions the M / G 12 as a generator, the inverter 21 converts the AC voltage from the M / G 12 into a DC voltage and supplies it to the battery 20 to charge the battery 20.

As shown in FIG. 2, the battery 20 has a characteristic that the open circuit voltage Vocv in each cell increases as the charge rate SOC increases. Further, the voltage in each cell becomes higher than the open circuit voltage Vocv during charging and lower during discharging. The highest voltage among the plurality of cells constituting the battery 20 is called the battery voltage Vbat, and the upper limit voltage Vmax is set in the battery voltage Vbat for the purpose of protecting the battery 20.

As shown in FIG. 1, the vehicle 10 includes a switch SW operated by a driver. The switch SW indicates the magnitude of the braking torque required by the driver when the accelerator is off. The switch SW has a normal position (SW = 0), a first position (SW = 1), and a second position (SW = 2) as operating positions. The normal position is an operation position indicating a normal torque T0, and the first position is an operation position indicating a first torque. The second position is an operating position indicating the second torque T2. Each time the switch SW is operated, the switch SW outputs an operation signal indicating an operation position to the hybrid ECU 31, which will be described later.

The engine 11, retarder 11a, clutch 15, inverter 21, and transmission 16 described above are controlled by a control device 30 that controls the vehicle 10.
The control device 30 is composed of a hybrid ECU 31, an engine ECU 32, an inverter ECU 33, a battery ECU 34, a transmission ECU 35, an information ECU 36, and the like, and the ECUs 31 to 36 are connected to each other via, for example, CAN (Control Area Network). ..

Each ECU (Electronic Control Unit) 31 to 36 is mainly composed of a microcontroller in which a processor, a memory, an input interface, an output interface, and the like are connected to each other via a bus. Each ECU 31 to 36 acquires state information, which is information about the state of the vehicle 10, via an input interface, and performs various processes based on the acquired state information, a control program stored in the memory, and various data. To execute.

The hybrid ECU 31 acquires various information output by each of the ECUs 32 to 36 via an input interface. For example, the hybrid ECU 31 has an accelerator opening ACC, which is the opening degree of the accelerator pedal 51, an engine rotation speed Ne, which is the rotation speed of the rotation shaft 13 of the engine 11, and a fuel injection amount in the engine 11, based on a signal from the engine ECU 32. Acquire Gf and so on. The hybrid ECU 31 acquires the motor rotation speed Nm, which is the rotation speed of the rotation shaft 14 of the M / G 12 based on the signal from the inverter ECU 33, and the battery voltage Vbat or the like based on the signal from the battery ECU 34. The hybrid ECU 31 acquires the engagement / disengagement state of the clutch 15, the gear ratio Rt in the transmission 16, and the like based on the signal from the transmission ECU 35. The hybrid ECU 31 acquires the vehicle speed v and the like based on the signal from the information ECU 36. As the operation position acquisition unit, the hybrid ECU 31 acquires the operation position of the switch SW based on the signal from the switch SW.

The hybrid ECU 31 generates various control signals based on the acquired information, and outputs the generated control signals to the ECUs 32 to 36 via the output interface.
The hybrid ECU 31 calculates an engine instruction torque Teref, which is an instruction torque to the engine 11, and outputs a control signal indicating the calculated engine instruction torque Teref to the engine ECU 32.

The hybrid ECU 31 outputs a first operating signal for operating the retarder 11a in the first operating state and a second operating signal for operating the retarder 11a in the second operating state as control signals to the engine ECU 32. The hybrid ECU 31 outputs a control signal to the retarder 11a based on the accelerator opening ACC, the engine speed Ne, the motor speed Nm, and the like at that time. Further, the hybrid ECU 31 outputs a stop signal for stopping the retarder 11a to the engine ECU 32 when a stop condition such as accelerator on is satisfied.

The hybrid ECU 31 calculates a motor instruction torque Tmref which is an instruction torque for the M / G 12, and outputs a control signal indicating the calculated motor instruction torque Tmref to the inverter ECU 33.

The hybrid ECU 31 outputs a control signal instructing the engagement / disengagement of the clutch 15 and a control signal indicating the gear ratio Rt in the transmission 16 to the transmission ECU 35.

The engine ECU 32 acquires the accelerator opening ACC as the opening degree acquisition unit, and the fuel injection amount Gf, injection timing, etc., so that the torque corresponding to the engine instruction torque Teref input from the hybrid ECU 31 acts on the rotating shaft 13. The output of the engine 11 is controlled by controlling the engine 11. Further, the engine ECU 32 controls the operating state of the retarder 11a based on the control signal input from the hybrid ECU 31. When the first operation signal is input from the hybrid ECU 31, the engine ECU 32 controls the retarder 11a to the first operation state until a stop signal or a second operation signal is input from the hybrid ECU 31. When the second operation signal is input from the hybrid ECU 31, the engine ECU 32 controls the retarder 11a to the second operation state until the stop signal or the first operation signal is input from the hybrid ECU 31.

The inverter ECU 33 acquires the motor rotation speed Nm as a rotation speed acquisition unit, and controls the inverter 21 so that the torque corresponding to the motor instruction torque Tmref input from the hybrid ECU 31 acts on the rotation shaft 14.

The battery ECU 34 monitors the charge / discharge current of the battery 20 and calculates the charge rate SOC of the battery 20 based on the integrated value of the charge / discharge current. As a voltage acquisition unit, the battery ECU 34 monitors the voltage value of each cell constituting the battery 20, and outputs the highest voltage value among the voltage values of each cell to the hybrid ECU 31 as the battery voltage Vbat.

The transmission ECU 35 controls the engagement / disengagement of the clutch 15 in response to the engagement / disengagement request of the clutch 15 from the hybrid ECU 31. Further, the transmission ECU 35 controls the gear ratio Rt of the transmission 16 based on the control signal indicating the gear ratio Rt from the hybrid ECU 31.

The information ECU 36 acquires information such as the vehicle speed v of the vehicle 10 based on a signal from the information acquisition unit 53 composed of, for example, a vehicle speed sensor, and outputs the acquired information to the hybrid ECU 31.

In the control device 30 having such a configuration, the hybrid ECU 31 executes various braking processes according to the operation position of the switch SW when the engine 11 is in the driving state and the accelerator opening ACC is 0 (accelerator off). To do. The hybrid ECU 31 has various braking processes such as a normal process executed when the switch SW is in the normal position, a first braking process executed when the switch SW is in the first position, and a switch SW in the second position. It has a second braking process that is performed at some point. The hybrid ECU 31 has a stop condition that the accelerator is operated in the on state during the execution of each braking process and that the switch SW is operated during the execution of each braking process. When the stop condition is satisfied, the hybrid ECU 31 forcibly ends the braking process during execution, and when the stop condition is based on the operation of the switch SW, braking according to the operation position of the switch SW after the operation. Start processing.

In explaining various braking processes, the relationship between the braking torque due to the engine brake according to the operating state of the retarder 11a and the braking torque due to the regeneration of the M / G 12 will be described with reference to FIG.

As shown in FIG. 3, the normal torque T0, the first torque T1 (> T0), and the second torque T2 (> T1) increase as the engine speed Ne, that is, the motor speed Nm increases. Further, in the regenerative torque Tr, the maximum regenerative torque Trmax is set at each motor rotation speed Nm. The maximum regenerative torque Trmax is a constant value larger than the second torque T2 in the range where the motor rotation speed Nm is the rotation speed N1 or less. The maximum regenerative torque Trmax is a value smaller as the motor rotation speed Nm increases in the range where the motor rotation speed Nm is larger than the rotation speed N1. The maximum regenerative torque Trmax becomes equal to the second torque T2 at the rotation speed N2, equals to the first torque T1 at the rotation speed N3, and equals to the normal torque T0 at the rotation speed N4. The regenerative torque Tr can be controlled to a size equal to or less than the maximum regenerative torque Trmax at each motor rotation speed Nm through the inverter 21.

As shown in FIG. 4, the normal process is a braking process in which the normal torque T0 is obtained as the braking torque. In the normal processing, the hybrid ECU 31 first outputs various control signals for controlling the clutch 15 in the disengaged state, the regenerative torque Tr in the normal torque T0, and the retarder 11a in the non-operating state (step S101). The state of step S101 is called a normal regeneration state. The battery voltage Vbat increases with respect to the open circuit voltage Vocv as the charging current increases as the regenerative torque Tr increases.

Next, the hybrid ECU 31 determines whether or not the battery voltage Vbat has reached the upper limit voltage Vmax (step S102). The hybrid ECU 31 maintains a normal regenerative state until the battery voltage Vbat reaches the upper limit voltage Vmax. When the battery voltage Vbat reaches the upper limit voltage Vmax (step S102: YES), the hybrid ECU 31 sets the clutch 15 in the connected state, the M / G 12 in the regenerative stop state (Tr = 0), and the retarder 11a in the inactive state. Various control signals to be controlled are output (step S103), and a series of processes is completed. The state of step S103 is usually referred to as a non-regenerative state.

As shown in FIG. 5, the first braking process is a braking process in which the first torque T1 is obtained as the braking torque. In the first braking process, the hybrid ECU 31 first outputs various control signals for controlling the clutch 15 in the disengaged state, the regenerative torque Tr in the first torque T1, and the retarder 11a in the non-operating state (step S201). The state of step S201 is referred to as the first regeneration state.

Next, the hybrid ECU 31 determines whether or not the battery voltage Vbat has reached the upper limit voltage Vmax (step S202). The hybrid ECU 31 maintains the first regenerative state until the battery voltage Vbat reaches the upper limit voltage Vmax. When the battery voltage Vbat reaches the upper limit voltage Vmax (step S202: YES), the hybrid ECU 31 has the clutch 15 connected, and the regenerative torque Tr is the first partial regenerative torque which is the difference between the first torque T1 and the normal torque T0. It outputs ΔTr1 (= T1-T0) and various control signals for controlling the retarder 11a in the non-operating state (step S203). The state of step S203 is referred to as the first partial regeneration state.

Next, the hybrid ECU 31 determines whether or not the battery voltage Vbat has reached the upper limit voltage Vmax (step S204). The hybrid ECU 31 maintains the first partial regenerative state until the battery voltage Vbat reaches the upper limit voltage Vmax. When the battery voltage Vbat reaches the upper limit voltage Vmax (step S204: YES), the hybrid ECU 31 controls the clutch 15 to the connected state, the M / G 12 to the regenerative stop state, and the retarder 11a to the first operating state. A signal is output (step S205), and a series of processes is completed. The state of step S205 is referred to as the first non-regenerative state.

As shown in FIG. 6, the second braking process is a braking process in which the second torque T2 is obtained as the braking torque. In the second braking process, the hybrid ECU 31 first outputs various control signals for controlling the clutch 15 in the disengaged state, the regenerative torque Tr in the second torque T2, and the retarder 11a in the non-operating state (step S301). The state of step S301 is referred to as the second regeneration state.

Next, the hybrid ECU 31 determines whether or not the battery voltage Vbat has reached the upper limit voltage Vmax (step S302). The hybrid ECU 31 maintains the second regeneration state until the battery voltage Vbat reaches the upper limit voltage Vmax. When the battery voltage Vbat reaches the upper limit voltage Vmax (step S302: YES), the hybrid ECU 31 has the clutch 15 connected, and the regenerative torque Tr is the difference between the second torque T2 and the first torque T1. The torque ΔTr2 (= T2-T1) and various control signals for controlling the retarder 11a to the first operating state are output (step S303). The state of step S303 is referred to as a second partial regeneration state.

Next, the hybrid ECU 31 determines whether or not the battery voltage Vbat has reached the upper limit voltage Vmax (step S304). The hybrid ECU 31 maintains the second partial regenerative state until the battery voltage Vbat reaches the upper limit voltage Vmax. When the battery voltage Vbat reaches the upper limit voltage Vmax (step S304: YES), the hybrid ECU 31 sends various control signals for controlling the clutch 15 to the connected state, the M / G 12 to the regenerative stop state, and the retarder 11a to the second operating state. Output (step S305), and a series of processing is completed. The state of step S305 is referred to as the second non-regenerative state.

At the time of transition from the regenerative state to the partial regenerative state, the hybrid ECU 31 shifts to the partial regenerative state after the battery voltage Vbat that has reached the upper limit voltage Vmax drops to the open circuit voltage Vocv. For example, the hybrid ECU 31 shifts to the partial regenerative state after the rate of change of the battery voltage Vbat in a unit time becomes equal to or less than the threshold value at which the battery voltage Vbat is determined to have dropped to the open circuit voltage Vocv. Further, in the transition from the regenerative state to the partial regenerative state, the hybrid ECU 31 elapses for a predetermined set period after the battery voltage Vbat reaches the upper limit voltage Vmax even if the battery voltage Vbat does not drop to the open circuit voltage Vocv. Then, it shifts to the partial regeneration state. This setting period is preferably set to the longest period in which the change in drivability is suppressed in order to bring the battery voltage Vbat closer to the open circuit voltage Vocv.

That is, if the battery voltage Vbat drops to the open circuit voltage Vocv before the set period elapses, the hybrid ECU 31 shifts to the partially regenerative state. Further, the hybrid ECU 31 shifts to the partial regeneration state after the set period elapses even if the battery voltage Vbat does not drop to the open circuit voltage Vocv. The period between this regenerative state and the partial regenerative state is called the transition period.

With reference to FIG. 7, the transition of the battery voltage Vbat in each of the first and second braking processes described above will be described.
As shown in FIG. 7, when the regenerative state is controlled at time t1, the battery 20 is charged in a state where the battery voltage Vbat is higher than the open circuit voltage Vocv by an increase width ΔVa. Then, at the time t2 when the battery voltage Vbat reaches the upper limit voltage Vmax, the regenerative state shifts to the partial regenerative state. The increase width ΔVb of the battery voltage Vbat in the partially regenerated state is smaller than the increase width ΔVa of the battery voltage Vbat in the regenerative state. Therefore, the partial regeneration state continues until the battery voltage Vbat becomes higher than the upper limit voltage Vmax again. By shifting from the regenerative state to the partial regenerative state in this way, the battery 20 can be continuously charged even if the battery voltage Vbat reaches the upper limit voltage Vmax in the regenerative state.

An example of the operation mode when the accelerator is off will be described with reference to FIGS. 8 and 9.
As shown in FIG. 8, when the switch SW is located at the first position, the driver requests the first torque T1 as the braking torque when the accelerator is off. Then, when the accelerator is operated to the off state at time t10, the first braking process is started, and when the battery voltage Vbat is smaller than the upper limit voltage Vmax, it is controlled to the first regeneration state.

As described above, in the first regenerative state, the clutch (C / L) 15 is in the disengaged state (OFF), the retarder 11a is in the non-operating state, and the regenerative torque Tr of the M / G 12 is controlled by the first torque T1. , The first torque T1 is realized by the regenerative torque Tr. At this time, the braking torque Ta by the engine brake is 0. Then, the battery voltage Vbat rises along with the charge rate SOC of the battery 20, and when the battery voltage Vbat reaches the upper limit voltage Vmax at time t11, the state shifts from the first regenerative state to the first partial regenerative state. At time t11, the battery 20 is at charge rate SOC11.

During the transition period from time t11 to time t12, the clutch 15 is controlled from the disengaged state to the connected state. Further, the regeneration by the M / G 12 is stopped, and the battery voltage Vbat drops to the open circuit voltage Vocv at that time. Due to the existence of this transition period, the battery voltage Vbat immediately after the transition to the first partial regenerative state can be lowered as compared with the case where the battery voltage Vbat is not lowered to the open circuit voltage Vocv at the time of transition.

In the first partial regenerative state, the clutch 15 is in the connected state (ON), the retarder 11a is in the non-operating state, and the regenerative torque Tr of the M / G 12 is controlled by the first partial regenerative torque ΔTr1. That is, in the first partial regenerative state, the first torque T1 is realized by the normal torque T0, which is the braking torque Ta by the normal engine brake, and the regenerative torque Tr by the M / G 12. Further, charging of the battery 20 is started from the charging rate SOC11. Then, the battery voltage Vbat rises along with the charge rate SOC of the battery 20, and when the battery voltage Vbat reaches the upper limit voltage Vmax at time t13, the state shifts from the first partial regenerative state to the first non-regenerative state. At this time, the charge rate SOC is increased to a charge rate SOC13 close to the maximum charge rate SOCmax.

In the first non-regenerative state, the clutch 15 is in the connected state, the retarder 11a is in the first operating state, and the regenerative torque Tr is controlled to 0, so that the first torque T1 is realized by the retarder 11a. Then, at time t14, when the switch SW is operated to the normal position (SW = 0), the retarder 11a is controlled to the non-operating state, so that the normal torque T0 by the engine brake acts as the braking torque Ta.

As shown in FIG. 9, when the switch SW is located at the second position, the driver requests the second torque T2 as the braking torque when the accelerator is off. Then, when the accelerator is operated to the off state at time t20, the second braking process is started, and when the battery voltage Vbat is smaller than the upper limit voltage Vmax, it is controlled to the second regenerative state.

As described above, in the second regenerative state, the clutch (C / L) 15 is in the disengaged state (OFF), the retarder 11a is in the non-operating state, and the regenerative torque Tr of the M / G 12 is controlled by the second torque T2. , The second torque T2 is realized by the regenerative torque Tr. At this time, the braking torque Ta by the engine brake is 0. Then, the battery voltage Vbat rises along with the charge rate SOC of the battery 20, and when the battery voltage Vbat reaches the upper limit voltage Vmax at time t21, the state shifts from the second regenerative state to the second partial regenerative state. At time t21, the battery 20 is at charge rate SOC21.

During the transition period from time t21 to time t22, the clutch 15 is controlled from the disengaged state to the connected state. Further, the regeneration by the M / G 12 is stopped, and the battery voltage Vbat drops to the open circuit voltage Vocv at that time.

In the second partial regenerative state, the clutch 15 is in the connected state (ON), the retarder 11a is in the first operating state, and the regenerative torque Tr of the M / G 12 is controlled by the second partial regenerative torque ΔTr2. That is, in the second partial regenerative state, the second torque T2 is realized by the first torque T1 by the retarder 11a and the regenerative torque Tr by the M / G 12. Further, charging of the battery 20 is started from the charging rate SOC21. Then, the battery voltage Vbat rises along with the charge rate SOC of the battery 20, and when the battery voltage Vbat reaches the upper limit voltage Vmax at time t23, the second partial regenerative state shifts to the second non-regenerative state. At this time, the charge rate SOC is increased to a charge rate SOC23 close to the maximum charge rate SOCmax.

In the second non-regenerative state, the clutch 15 is connected, the retarder 11a is in the second operating state, and the regenerative torque Tr is controlled to 0, so that the second torque T2 is realized by the retarder 11a. Then, at time t24, when the switch SW is operated to the first position, the first braking process is started and the first non-regenerative state is controlled. That is, the first torque T1 by the retarder 11a acts as the braking torque Ta. After that, when the switch SW is operated to the normal position at time t25, the normal processing is started and the normal non-regenerative state is controlled. That is, the normal torque T0 generated by the engine brake acts as the braking torque Ta.

According to the control device 30 of the above embodiment, the effects listed below can be obtained.
(1) In the first and second braking processes, when the battery voltage Vbat reaches the upper limit voltage Vmax while in the regenerative state, the state shifts to the partial regenerative state. In the partially regenerated state, the rising width ΔVb of the battery voltage Vbat is smaller than the rising width ΔVa in the regenerated state. Therefore, even after the battery voltage Vbat reaches the upper limit voltage Vmax in the regenerated state, the battery 20 is continuously charged. Can be done. As a result, the battery 20 can be effectively charged while obtaining the braking torque according to the operation position of the switch SW.

(2) In the first and second braking processes, when the battery voltage Vbat reaches the upper limit voltage Vmax in the partially regenerative state, the state shifts to the non-regenerative state. According to such a configuration, the battery 20 can be charged to a higher charge rate SOC before shifting to the non-regenerative state, and the required braking torque can be obtained while suppressing the battery voltage Vbat from exceeding the upper limit voltage Vmax. Can be done.

(3) In the first and second braking processes, when the battery voltage Vbat reaches the upper limit voltage Vmax in the regenerative state, the hybrid ECU 31 shifts to the partial regenerative state after the battery voltage Vbat drops to the open circuit voltage Vocv. Further, even if the battery voltage Vbat does not drop to the open circuit voltage Vocv, the hybrid ECU 31 shifts to the partially regenerated state after a lapse of a predetermined set period. According to such a configuration, the battery voltage Vbat drops to the vicinity of the open circuit voltage Vocv during the transition period, so that the battery voltage Vbat immediately after the transition to the partially regenerative state is increased by the increase width ΔVb from the open circuit voltage Vocv at that time. can do. As a result, the battery voltage Vbat immediately after the transition to the partial regenerative state becomes lower than the case where the battery voltage Vbat shifts to the partial regenerative state before the battery voltage Vbat drops to the vicinity of the open circuit voltage Vocv, so that the battery reaches a higher charge rate SOC. 20 can be charged. Further, the clutch 15 can be switched from the disengaged state to the connected state by utilizing this transition period.

(4) The hybrid ECU 31 performs a normal process, a first braking process, and a second braking process according to the operation position of the switch SW. As a result, the battery 20 can be effectively charged while obtaining the braking torque required by the driver.

(5) The open circuit voltage Vocv of the battery 20 may differ depending on the temperature conditions and deterioration states at that time. In this respect, each braking process is configured so that the regenerative state is once performed and then the partial regenerative state is performed. Therefore, it is possible to determine in what state the regeneration is performed according to the open circuit voltage Vocv at that time under a simple configuration.

The above embodiment can be modified as appropriate and implemented as follows.
The hybrid ECU 31 may be configured to execute only the second braking process on the vehicle 10 that does not have the switch SW, that is, the vehicle 10 in which the engine brake is constantly increased by the retarder 11a when the accelerator is off. ..

-At the time of transition from the regenerative state to the partial regenerative state, the hybrid ECU 31 may shift to the partial regenerative state after the battery voltage Vbat drops to the open circuit voltage Vocv. Therefore, the hybrid ECU 31 may shift to the partially regenerated state based on the value of the battery voltage Vbat itself, not limited to the rate of change of the battery voltage Vbat. In such a configuration, the hybrid ECU 31 compares the battery voltage Vbat with the open circuit voltage Vocv corresponding to the charge rate SOC at each time based on the characteristics of the battery 20 shown in FIG. 2, so that the battery voltage Vbat reaches the open circuit voltage Vocv. Determine if it has declined.

-The set period may be a period in which the battery voltage Vbat is considered to have dropped to the open circuit voltage Vocv. In this case, the setting period is preferably set based on the results of experiments and simulations performed on the transition of the battery voltage Vbat after charging, and is preferably set to a period in which the change in drivability is suppressed. .. The hybrid ECU 31 may be configured to shift to the partial regeneration state after a lapse of a set period without being based on the battery voltage Vbat.

As shown in FIG. 10, the retarder 11a may have a third operating state in which a third torque T3, which is larger than the first torque T1 and smaller than the second torque T2, is obtained as the braking torque. .. In this case, in the second braking process, when the battery voltage Vbat reaches the upper limit voltage Vmax in the second partial regenerative state, the clutch 15 is connected and the regenerative torque Tr of the M / G 12 is set to the second torque T2. It is preferable to shift to the third partial regenerative torque ΔTr3 (= T2-T3), which is the difference between the third torque T3 and the third torque T3, and the third partial regenerative state in which the retarder 11a is controlled to the third operating state. According to such a configuration, the increase width of the battery voltage Vbat in the third partial regeneration state becomes smaller than the increase width in the second partial regeneration state, so that the battery 20 can be further charged. By gradually reducing the proportion of the regenerative torque Tr in the braking torque according to the operation position of the switch SW in this way, the battery 20 can be charged more effectively.

-The auxiliary brake may be any one that increases the braking torque of the engine brake when the accelerator is off. Therefore, the auxiliary brake is not limited to the retarder 11a that performs the compression release operation, and may be, for example, an exhaust brake that increases the braking torque by the engine brake by reducing the cross-sectional area of the flow path in the exhaust passage of the engine 11.

The control device 30 may be composed of one ECU.

10 ... vehicle, 11 ... engine, 11a ... retarder, 12 ... motor generator, 13 ... rotating shaft, 14 ... rotating shaft, 15 ... clutch, 16 ... transmission, 17 ... drive shaft, 18 ... driving wheel, 20 ... battery, 21 ... Inverter, 30 ... Control device, 31 ... Hybrid ECU, 32 ... Engine ECU, 33 ... Inverter ECU, 34 ... Battery ECU, 35 ... Transmission ECU, 36 ... Information ECU, 51 ... Accelerator pedal, 53 ... Information acquisition unit, SW …switch.

Claims (4)

A vehicle control device installed in a hybrid vehicle.
The hybrid vehicle is a first clutch that connects the rotating shaft of the engine and the rotating shaft of the motor generator in a connectable manner, and an auxiliary brake that increases the braking torque by the engine brake when the accelerator is off, so that the first torque can be obtained. The auxiliary brake has an operating state and a second operating state in which a second torque larger than the first torque is obtained.
The vehicle control device includes a voltage acquisition unit that acquires a battery voltage, a control unit that controls engagement / disengagement of the clutch, regenerative torque of the motor generator, and an operating state of the auxiliary brake.
The control unit controls the clutch in the disengaged state, the regenerative torque in the second torque, and the auxiliary brake in the non-operating state, the clutch in the connected state, and the regenerative torque in the second torque. It has a difference between the first torque and the first torque, and a partial regenerative state that controls the auxiliary brake to the first operating state. When the battery voltage reaches the upper limit voltage in the regenerative state, the regenerative torque is reduced to 0. A vehicle control device that shifts to the partially regenerative state after a transition period . The control unit has a non-regenerative state in which the clutch is engaged, the regenerative torque is 0, and the auxiliary brake is controlled in the second operating state. In the partial regenerative state, the battery voltage is the upper limit voltage. The vehicle control device according to claim 1, wherein the vehicle shifts to the non-regenerative state when the vehicle reaches. The vehicle control device according to claim 1 or 2, wherein the control unit shifts to the partially regenerative state after the battery voltage drops to the open circuit voltage during the transition period . The hybrid vehicle is a switch in which the driver selects the braking torque obtained by the engine brake when the accelerator is off, and the operating position is the braking torque by the normal engine brake when the auxiliary brake is in the non-operating state. The switch has a normal position indicating a torque, a first position indicating the first torque, and a second position indicating the second torque.
The vehicle control device includes an operation position acquisition unit that acquires the operation position.
The control unit sets the regeneration torque to 0 from the second regenerative state, which is the regenerative state, to the second partial regenerative state, which is the partial regenerative state, when the switch is located at the second position. the is configured to migrate through, further the clutch disconnected state, the first torque the regenerative torque, and a first regenerative state for controlling the auxiliary brake inoperative, connecting the clutch It has a state, a difference between the first torque and the normal torque for the regenerative torque, and a first partial regenerative state for controlling the auxiliary brake to a non-operating state, and the switch is located at the first position. Any one of claims 1 to 3 that shifts to the first partial regenerative state after a transition period in which the regenerative torque is set to 0 when the battery voltage reaches the upper limit voltage in the first regenerative state. The vehicle control device according to the section.

Images