Control device

Abstract

To prepare for travel under the next first control after completion of the first control.SOLUTION: When a switch is turned on and a first condition is satisfied, a control device executes first control that controls an engine and first and second motors such that power output is prioritized over fuel efficiency until the power storage ratio of a battery becomes equal to or less than a lower limit ratio or a first ratio in the vicinity of the lower limit ratio. When the switch is turned on and a second condition different from the first condition is satisfied during the first control, the control device terminates the first control and starts a second control that controls the engine and the first and second motors such that the power storage ratio of the battery becomes an upper limit ratio greater than the first ratio or a second ratio equal in the vicinity of the upper limit ratio.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a control device. [Background technology]

[0002] Conventionally, this type of control device has been proposed for use in hybrid vehicles equipped with an engine that outputs power for driving, a first motor (generator) that generates electricity using power from the engine, a second motor (front motor) that outputs power for driving, and a battery (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-136973 Summary of the Invention [Problem to be solved by the invention]

[0004] Some of the above-mentioned control devices execute a first control that controls the engine and the first and second motors so that the battery's charge ratio becomes a first ratio that is a lower limit ratio or a ratio close to the lower limit ratio when the switch is turned on. In such control devices, it is recognized that an important issue is to bring the battery close to full charge after the first control ends in preparation for the next running under the first control.

[0005] The main purpose of the control device of the present disclosure is to prepare for the next running under the first control after the first control has ended. [Means for solving the problem]

[0006] The control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The control device disclosed herein is used in a hybrid vehicle including an engine, a first motor, a planetary gear having three rotating elements connected to the engine, the first motor, and a drive shaft connected to an axle, a second motor connected to the drive shaft, a battery that exchanges power with the first and second motors, and a switch that instructs driving that prioritizes power output over fuel efficiency, and controls the engine and the first and second motors. When a first condition is satisfied while the switch is on, the control device executes a first control that controls the engine and the first and second motors so as to drive by prioritizing power output over fuel efficiency until the battery's power storage rate becomes equal to or lower than a lower limit rate or a first rate close to the lower limit rate. When a second condition different from the first condition is satisfied while the switch is on during the first control, the control device terminates the first control and starts executing a second control that controls the engine and the first and second motors so that the battery's power storage rate becomes an upper limit rate greater than the first rate or a second rate close to the upper limit rate. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the outline of the configuration of a hybrid vehicle 20. [Figure 2] 4 is a flowchart showing an example of a control routine. [Figure 3] 10 is a flowchart showing an example of a setting routine. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating the configuration of a hybrid vehicle 20 equipped with a control device according to the present embodiment. As illustrated, the hybrid vehicle 20 according to the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2 (first and second motors), inverters 41 and 42, a battery 50, a system main relay 56, an auxiliary battery 60, a DC / DC converter 62, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70. The HVECU 70, an engine electronic control unit (hereinafter referred to as "engine ECU") 24, a motor electronic control unit (hereinafter referred to as "motor ECU") 40, and a battery electronic control unit (hereinafter referred to as "battery ECU") 52 (described later) are configured as microprocessors centered around a CPU (not shown), and in addition to the CPU, include a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, and communication ports.

[0010] The engine 22 is configured as an internal combustion engine that outputs power using gasoline, diesel, or the like as fuel. The operation of the engine 22 is controlled by an engine ECU 24. The engine ECU 24 receives, via an input port, a crank angle θcr and other signals from a crank position sensor 23 that detects the rotational position of a crankshaft 26 of the engine 22. The engine ECU 24 outputs various control signals for controlling the operation of the engine 22 via an output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

[0011] The planetary gear 30 is configured as a single-pinion planetary gear mechanism. A rotor of a motor MG1 is connected to a sun gear of the planetary gear 30, a drive shaft 36 connected to drive wheels 39a, 39b via a differential gear 38 is connected to a ring gear, and the crankshaft 26 of the engine 22 is connected to a carrier.

[0012] Motor MG1 is configured as a synchronous generator motor having a rotor with a permanent magnet embedded therein and a stator around which a three-phase coil is wound, and as described above, the rotor is connected to the sun gear of planetary gear 30. Motor MG2, like motor MG1, is configured as a synchronous generator motor, and its rotor is connected to drive shaft 36.

[0013] The inverter 41 is connected to the power line 54 and is configured as a well-known inverter circuit having six transistors and six diodes. Like the inverter 41, the inverter 42 is also connected to the power line 54 and is configured as a well-known inverter circuit having six transistors and six diodes. The inverters 41 and 42 are controlled by the motor ECU 40. The motor ECU 40 receives rotational positions θm1 and θm2, etc. from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, via an input port. The motor ECU 40 outputs switching control signals, etc., to the transistors of the inverters 41 and 42 via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position detection sensors 43 and 44.

[0014] The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and is connected to a power line 54. The battery 50 is managed by a battery ECU 52. The battery ECU 52 receives, via an input port, a voltage Vb of the battery 50 from a voltage sensor 51a attached between the terminals of the battery 50, a current Ib of the battery 50 from a current sensor 51b attached to an output terminal of the battery 50, and a temperature Tb of the battery 50 from a temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates a power storage ratio SOC based on an integrated value of the current Ib of the battery 50 from the current sensor 51b. The power storage ratio SOC is the ratio of the amount of power that can be discharged from the battery 50 to the total capacity of the battery 50. The battery ECU 52 also calculates an output limit Wout and an input limit Win of the battery 50 based on the temperature Tb of the battery 50 from the temperature sensor 51c and the power storage ratio SOC. The output limit Wout is the maximum allowable power (power of a positive value) that may be discharged from the battery 50. The input limit Win is the maximum allowable power (power of a negative value) that may be charged to the battery 50.

[0015] Auxiliary battery 60 is configured as a storage battery, for example a lead storage battery, with a lower voltage than battery 50, and is connected to auxiliary power line 64. Auxiliary power line 64 is connected to low-voltage side power line 54b via a bidirectional DC / DC converter 62. Auxiliary equipment 66 such as a steering device is connected to auxiliary power line 64.

[0016] The HVECU 70 receives inputs, via an input port, of accelerator opening Acc from an accelerator pedal position sensor 84 that detects the depression amount of an accelerator pedal 83, vehicle speed V from a vehicle speed sensor 88, and a switch 90 that instructs driving that prioritizes power output over fuel economy. The HVECU 70 outputs, via an output port, drive control signals to the DC / DC converter 62, etc. As described above, the HVECU 70 is connected to the engine ECU 24, motor ECU 40, and battery ECU 52 via communication ports.

[0017] The hybrid vehicle 20 of this embodiment configured as described above runs in an HV running mode, an EV running mode, etc. The HV running mode is a running mode in which the engine 22 is running and the motors MG1 and MG2 are driven. The EV running mode is a running mode in which the engine 22 is stopped and the motor MG2 is driven.

[0018] In the EV driving mode, the HVECU 70 first sets a required torque Td* required for driving based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm1* for the motor MG1 to 0, and sets a torque command Tm2* for the motor MG2 so that the required torque Td* is output to the drive wheels 39a and 39b. The HVECU 70 then transmits the set torque commands Tm1* and Tm2* for the motors MG1 and MG2 to the motor ECU 40. The motor ECU 40 controls the switching of multiple transistors in the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1* and Tm2*.

[0019] In the HV driving mode, the HVECU 70 sets the required torque Td* using the same processing as in the EV driving mode, and then sets the required power Pd* that the driver requests for driving based on the set required torque Td* and the vehicle speed V. Next, the HVECU 70 sets the power Psoc required for the battery 50 to approach the target rate SOC* as the required charge / discharge power Pb* (a positive value when discharging from the battery 50), and calculates the required power Pe* required of the engine 22 by subtracting the required charge / discharge power Pb* from the required power Pd*. After setting the required power Pe* in this manner, the HVECU 70 sets the target rotation speed Ne* of the engine 22, the target torque Te*, and the torque commands Tm1* and Tm2* of the motors MG1 and MG2 so that the required power Pe* is output from the engine 22 and the required torque Td* is output to the drive wheels 39a and 39b while charging and discharging the battery 50 with power within the ranges of the input / output limits Win and Wout, and transmits these to the engine ECU 24 and the motor ECU 40. The engine ECU 24 controls the intake air amount, fuel injection, ignition, etc. of the engine 22 so that the engine 22 operates at the target rotation speed Ne* and target torque Te*. The motor ECU 40 controls the switching of multiple transistors of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1* and Tm2*.

[0020] Next, the operation of the hybrid vehicle 20 of this embodiment configured as described above, particularly the operation when the switch 90 is turned on, will be described. FIG. 2 is a flowchart showing an example of a control routine executed by the HVECU 70. This routine is repeatedly executed at predetermined time intervals (e.g., every few milliseconds) when the switch 90 is turned on. When this routine is executed, the CPU of the HVECU 70 inputs the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, and a flag F (S100). The flag F indicates whether the first control (sports driving control) is in progress. The flag F is set to 1 in S170 (described later) and to 0 in S150, and is initially set to 0. Next, it is determined whether the accelerator opening Acc is equal to or greater than a threshold value Accref (the first condition is met) (S110), whether the flag F is 1 (S120), and whether the vehicle speed V is 0 (the second condition is met) (S130). The threshold value Accref is a threshold value (e.g., 100%) for determining whether the accelerator opening Acc is fully open or not. When the accelerator opening Acc is less than the threshold value Accref in S110, if the flag F is not set to 1 in S120 or if the flag F is set to 1 and the vehicle speed V is set to 0 in S120, the second control (charging control) is executed (S140), the flag F is set to 0 (S150), and the control routine ends. When the accelerator opening Acc is equal to or greater than the threshold value Accref in S110, the first control is executed (S160), the flag F is set to 1 (S170), and the routine ends. The first control runs the vehicle in EV driving mode, prioritizing power output over fuel efficiency, until the storage ratio SOC of the battery 50 reaches a lower limit Smin (e.g., 20%) determined in advance through experiments, analysis, and machine learning as the lower limit of the storage ratio, or a threshold SOC1 (first ratio), which is a ratio close to that limit, and then runs the vehicle in HV driving mode once the storage ratio SOC of the battery 50 reaches the threshold SOC1 or less.

[0021] Here, the second control will be described. The second control is a control in the above-described HV running mode that uses the required charge / discharge power Pb*, input / output limits Win, and Wout, which are set by a setting routine described later, as the required charge / discharge power Pb* and input / output limits Win and Wout. FIG. 3 is a flowchart showing an example of the setting routine executed by the HVECU 70. When the setting routine is executed, the CPU of the HVECU 70 inputs the power storage ratio SOC calculated by the battery ECU 52 via communication and also inputs a flag Fc (S200). The flag Fc indicates whether the battery 50 is being charged, and is set to a value of 1 in S270 (described later), set to a value of 0 in S300, and set to a value of 0 as an initial value. Next, it is determined whether the flag Fc is set to a value of 1 (S210). When the flag Fc is set to a value of 1, the threshold SOCref (second rate) is set to an upper limit rate Smax previously determined through experiments, analysis, or machine learning as an upper limit value of the power storage rate allowed for the battery 50, or a value S1 (e.g., 80%) that is a rate close to the upper limit rate Smax (S220). When the flag Fc is set to a value of 0, the threshold SOCref is set to a value S2 (e.g., 78%) that is several percent lower than the value S1 (S230). Next, it is determined whether the power storage rate SOC is equal to or lower than the threshold SOCref (S240). When the power storage rate SOC is equal to or lower than the threshold SOCref, it is determined that the battery 50 is not fully charged, and the charge / discharge required power Pb* is set to a predetermined power Pbref (S250). The predetermined power Pbref is a value (e.g., −10 kW) previously determined through experiments, analysis, machine learning, or the like as a power that does not excessively extend the charging time of the battery 50 or excessively increase the load on the battery 50. Then, the input limit Win is set to a predetermined power Win1, and the output limit Wout is set to a value of 0 (S260). The predetermined power Win1 is a predetermined power (e.g., -10 kW) that is the smallest power within the range of charging power that can charge the battery 50 when the battery degradation is progressing slowly. Furthermore, the flag Fc is set to a value of 1 (S270), and the setting routine ends.In the second control using the thus-set required charge / discharge power Pb* and input / output limits Win and Wout, the battery 50 is charged at the required charge / discharge power Pb* (=Pbref) while suppressing output from the battery 50. When the power storage ratio SOC exceeds the threshold value SOCref in S240, the battery 50 is determined to be fully charged, and the required charge / discharge power Pb* is set to 0 (S280), the input / output limits Win and Wout are set to 0 (S290), and the flag Fc is set to 0 (S300), and the setting routine ends. In the second control using the thus-set required charge / discharge power Pb* and input / output limits Win and Wout, charging and discharging of the battery 50 is suppressed to maintain the power storage ratio SOC of the battery 50, but the power consumption of the accessories 66 causes the power storage ratio SOC to decrease. In this case, when the power storage ratio SOC becomes equal to or less than the threshold value SOCref (=S2) in S240, S250 to S270 are executed, and the battery 50 is charged with the required charge / discharge power Pb* (=Pbref) while suppressing the output from the battery 50.

[0022] When switch 90 is turned on (flag F is initially set to 0), and the accelerator opening Acc is less than threshold value Accref, second control at S140 is executed to charge battery 50 or maintain it at a near-fully charged state. When accelerator opening Acc is equal to or greater than threshold value Accref, first control at S160 is executed to reduce the state of charge SOC. If the vehicle is stopped at S130 during first control, first control is terminated and second control at S140 is initiated to charge battery 50, thereby preparing for the next run under first control.

[0023] According to the control device of this embodiment described above, if the vehicle stops during the first control while switch 90 is on, the first control is terminated and the second control is started to be executed, thereby preparing for the next driving under the first control.

[0024] Note that the correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section. Although the embodiments for implementing the present disclosure have been described above, the present disclosure is not limited to these embodiments, and of course can be implemented in various forms within the scope of the present disclosure. [Explanation of symbols]

[0025] 20 Hybrid Vehicles, 70 Hybrid Electronic Control Units (HVECUs).

Claims

[Claim 1] A control device for use in a hybrid vehicle including an engine, a first motor, a planetary gear having three rotating elements connected to the engine, the first motor, and a drive shaft connected to an axle, a second motor connected to the drive shaft, a battery that exchanges electric power with the first and second motors, and a switch that instructs driving that prioritizes power output over fuel economy, the control device controlling the engine and the first and second motors, When a first condition is satisfied while the switch is on, a first control is executed to control the engine and the first and second motors so that the vehicle runs while prioritizing power output over fuel efficiency until the charge rate of the battery becomes equal to or lower than a lower limit rate or a first rate close to the lower limit rate, When a second condition different from the first condition is satisfied during the first control while the switch is on, the first control is terminated and execution of a second control is started in which the engine and the first and second motors are controlled so that the power storage rate of the battery becomes an upper limit rate that is greater than the first rate or a second rate that is close to the upper limit rate. Control device.

Images