Control device for a vehicle

Abstract

A control device for a vehicle that suppresses loss of opportunity to execute idle stop control and suppresses erroneous permission of idle stop control. At the time of power-on, if the permission determination result of idle stop control stored at the time of last power-off is permission, and if the voltage passivation value after a passivation process is performed on the output voltage of the electric storage device during the period from the power-on time point to the time point of a predetermined time at which an initialization process is executed is a predetermined voltage or more that can ensure engine start, idle stop control is permitted, so regardless of the length of the period from the last power-off time point to the present power-on time point, the state of the electric storage device including discharge of the electric storage device can be inferred from the voltage passivation value, and by comparing the permission determination using the voltage passivation value with the permission determination result stored at the time of last vehicle power-off, the determination accuracy of the permission determination of idle stop control at the present power-on can be ensured.

Description

Technical Field

[0001] This invention relates to a control device for a vehicle equipped with an engine starting device. Background Technology

[0002] Vehicle control devices equipped with an engine and a starting device are well known. The starting device includes a motor configured to drive the engine to rotate and an energy storage device that supplies power to the motor, thereby starting the engine. For example, the engine control device described in Patent Document 1 is such a device. Patent Document 1 discloses the following technique: before determining the battery charging rate after the vehicle has started, if the time elapsed since the vehicle last stopped is within a certain period, it determines whether the automatic stop condition for the engine based on idle stop control is met, based on the battery charging rate calculated at the time the vehicle last stopped.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-113724 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, the longer the storage time, the more easily the battery's charge rate decreases due to discharge. In contrast, Patent Document 1 discloses a technique where the higher the battery's charge rate at the time of the last stop, the longer the storage time is set. However, the determination is based solely on the battery's charge rate at the time of the last stop. Therefore, it is possible to erroneously allow idle stop control. Alternatively, in a method based on the battery's charge rate at the time of the last stop, if the storage time exceeds a certain period, idle stop control is not allowed, thus potentially excessively missing opportunities to execute idle stop control.

[0008] The present invention was made against the background of the above circumstances, and its object is to provide a vehicle control device that can suppress the loss of opportunity to perform idle stop control and suppress the false permission of idle stop control.

[0009] Technical solutions for solving the problem

[0010] The essence of the first invention is: (a) a control device for a vehicle, the vehicle having an engine and a starting device, the starting device having a motor configured to drive the engine to rotate and an energy storage device for supplying power to the motor, the engine being started using the motor, the control device for the vehicle including a starting control unit, the starting control unit (b) determining whether to allow idle stop control that temporarily stops the operation of the engine based on whether the state of the energy storage device is such that the engine can be started by the starting device, and storing the permission determination result of the idle stop control when the power supply to the vehicle is disconnected, on the other hand, (c) when the power supply to the vehicle is turned on, if the permission determination result of the idle stop control stored at the last time the power supply was disconnected is allowed, and the voltage passivation value after passivation processing of the output voltage of the energy storage device during the period from the time the power supply is turned on to the time when the initialization process of the control device is executed is above a predetermined voltage that can guarantee the starting of the engine, the idle stop control is allowed.

[0011] Furthermore, in the control device of the vehicle described in the first invention, the second invention, when the power is turned on, if the allowable determination result of the idle stop control stored when the power was last turned off is not allowed, or if the voltage passivation value is lower than the predetermined voltage, the starting control unit does not allow the idle stop control and performs the start-up using the motor. The starting control unit then determines again whether to allow the idle stop control based on whether the output voltage of the energy storage device during the start-up transition is a second predetermined voltage that is set to a value lower than the predetermined voltage and can guarantee the start-up of the engine.

[0012] Furthermore, in the vehicle control device described in the second invention, the third invention includes idle stop control comprising idle stop control before starting and idle stop control after starting. Idle stop control before starting is a control that prevents the engine from starting and keeps it in a standby state when the power is turned on but the vehicle is not started, while idle stop control after starting is a control that temporarily stops the running engine while the vehicle is moving or stopped. Idle stop control before starting is the idle stop control that stores the permission determination result when the power is off. Idle stop control before starting is the idle stop control that performs the permission determination when the power is turned on. Idle stop control after starting is the idle stop control that does not allow idle stop control before starting when the power is turned on but performs the permission determination when the motor is started.

[0013] Furthermore, in the control device of the vehicle described in any one of the first to third inventions, the fourth invention involves the starting control unit setting a voltage value above the open-circuit voltage of the energy storage device as the initial value of the voltage passivation value and starting the passivation process.

[0014] Furthermore, in the vehicle control device described in any one of the first to third inventions, the fifth invention allows the idle stop control when the power is turned on, provided that the voltage passivation value is above the predetermined voltage and the temperature of the energy storage device is above the predetermined temperature that can guarantee the starting of the engine.

[0015] Invention Effects

[0016] According to the first invention, when the vehicle's power is turned on, if the idle stop control permission determination result stored at the last time the vehicle's power was turned off is allowed, and the voltage passivation value after passivation processing of the battery's output voltage during the predetermined time from the power-on time to the time when the initialization process of the control device is executed is above a predetermined voltage that can guarantee engine starting, then idle stop control is allowed. Therefore, regardless of the length of the period from the last power-off time to the current power-on time, the current state of the battery, including the battery's discharge, can be inferred from the voltage passivation value. By comparing the permission determination result using the voltage passivation value with the permission determination result stored at the last time the vehicle's power was turned off, the accuracy of the permission determination for idle stop control at the time of power-on can be ensured. Thus, the loss of opportunity to execute idle stop control can be suppressed, and false permission of idle stop control can be suppressed.

[0017] Furthermore, according to the second invention, when the power is turned on, if the determination result of the allowance of idle stop control stored at the time of the last power disconnection is not allowed, or if the voltage passivation value is lower than a predetermined voltage, idle stop control is not allowed, thus suppressing false allowance of idle stop control. At this time, when starting the motor, the determination of whether idle stop control is allowed is made again based on whether the output voltage of the energy storage device during the start-up transition is higher than a second predetermined voltage that can guarantee engine starting, thus suppressing the loss of opportunity to perform idle stop control.

[0018] Furthermore, according to the third invention, the idle stop control that stores the permission determination result when the power is off is the idle stop control before starting, and the idle stop control that performs the permission determination when the power is on is the idle stop control before starting. Therefore, it is possible to suppress the loss of opportunity to perform idle stop control before starting and to suppress false permission of idle stop control before starting. Additionally, the idle stop control that does not allow idle stop control before starting when the power is on but performs the permission determination when starting the motor is used is the idle stop control after starting. Therefore, it is possible to suppress the loss of opportunity to perform idle stop control after starting.

[0019] Furthermore, according to the fourth invention, the voltage value above the open-circuit voltage of the energy storage device is set as the initial value of the voltage passivation value and passivation treatment is started. Therefore, it is possible to suppress the inrush current caused by the capacitor component after the power is turned on and the voltage drop caused by the operation of the equipment, thus preventing misjudgments.

[0020] Furthermore, according to the fifth invention, when the power is turned on, idling stop control is allowed when the voltage passivation value is above a predetermined voltage and the temperature of the energy storage device is above a predetermined temperature that can ensure the starting of the engine. Therefore, by taking into account the temperature that affects the output power of the energy storage device, the accuracy of the determination of whether idling stop control is allowed when the power is turned on can be appropriately ensured. Attached Figure Description

[0021] Figure 1 This is a diagram illustrating the general configuration of a vehicle to which the present invention is applied, and also a diagram illustrating the control functions and main parts of the control system used for various controls in the vehicle.

[0022] Figure 2 This is a diagram showing an example of the starter voltage when starting an engine using a second starting device (starter motor).

[0023] Figure 3 It is a flowchart illustrating the main parts of the control operation of the electronic control device, a flowchart for suppressing the loss of the opportunity to perform idle stop control and suppressing the false permission of idle stop control, and a flowchart executed in the previous stroke.

[0024] Figure 4 This is a flowchart illustrating the main parts of the control operation of the electronic control device. It is a flowchart for the control operation used to suppress the loss of the opportunity to perform idle stop control and to suppress the false permission of idle stop control. It is a flowchart executed in this trip.

[0025] Explanation of reference numerals in the attached figures

[0026] 10: Vehicles

[0027] 12: Engine

[0028] 18: Second starting device (starting device)

[0029] 32: Starter motor (motor)

[0030] 34: Low-voltage battery (energy storage device)

[0031] 70: Electronic control device (control device)

[0032] 76: Starting Control Unit Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] Example

[0035] Figure 1 This diagram illustrates the general configuration of a vehicle 10 to which the present invention is applied, and also illustrates the control functions and main components of the control system used for various controls in the vehicle 10. Figure 1 In the vehicle 10, there is an engine 12, an automatic transmission 14, a first starting device 16, a second starting device 18, a DC-DC converter 20, an electrical load 22, a start button 24, etc.

[0036] Engine 12 is the power source of vehicle 10. Engine 12 is a known internal combustion engine such as a gasoline engine or a diesel engine. Engine 12 controls its output torque, i.e., engine torque Te, by using an electronic control device 70 (described later) to control an engine control device (not shown) that includes a throttle actuator, a fuel injection device, an ignition device, etc.

[0037] The automatic transmission 14 may be, for example, a known planetary gear automatic transmission, a known dual-clutch transmission (DCT) of the same meshing type parallel two-shaft type, a known belt-type continuously variable transmission (CVT), or a known electric continuously variable transmission (CVT). The automatic transmission 14 is connected to the engine 12 in a manner capable of transmitting power, and transmits power from the engine 12 to the drive wheel side (not shown).

[0038] The first starting device 16 includes an electric motor MG and a high-voltage battery 26. The electric motor MG is an electric generator that functions as both an engine that generates mechanical power using electricity and a generator that generates electricity using mechanical power. The electric motor MG is connected to the high-voltage battery 26 via an integrated converter. The high-voltage battery 26 is an energy storage device that receives and supplies power to the electric motor MG. The electric motor MG's torque, i.e., MG torque Tm, is controlled by the converter using the electronic control device 70 described later. During traction, the electric motor MG is driven using power supplied from the high-voltage battery 26. During regeneration, the electric motor MG supplies the generated electricity to the high-voltage battery 26.

[0039] The electric motor MG is connected to the crankshaft 12a of the engine 12 via the drive belt 28 of the vehicle 10 in a manner capable of transmitting power. Therefore, the electric motor MG has the function of driving the engine 12 to rotate through traction when the engine 12 is stopped, thus starting the engine 12. In other words, the first starting device 16 is a starting device that uses the electric motor MG to start the engine 12. Furthermore, the electric motor MG has the function of assisting the engine 12's power through traction when the engine 12 is running. Additionally, the electric motor MG has the function of generating electricity using the engine 12's power through regenerative braking when the engine 12 is running. Furthermore, the electric motor MG has the function of generating electricity by utilizing the driven force input from the drive wheels through regenerative braking during deceleration.

[0040] Similar to the electric motor MG, auxiliary equipment in the vehicle 10, such as the A / C compressor 30 (which serves as an air conditioning compressor), a power steering pump (not shown), and a water pump (not shown), are operatively connected to the crankshaft 12a of the engine 12 via a drive belt 28, and are each driven by the engine 12. When the electric motor MG, A / C compressor 30, etc., are connected to the crankshaft 12a, for example, via an electromagnetic clutch (not shown), the auxiliary equipment such as the A / C compressor 30 is released by the electromagnetic clutch and is driven solely by the operation of the electric motor MG. In other words, the electric motor MG has the function of driving the auxiliary equipment such as the A / C compressor 30 during the idle stop control CTspidl, which temporarily stops the operation of the engine 12.

[0041] The idle stop control CTspidl is an automatic engine stop control that automatically stops the engine 12 from operating due to factors such as fuel cut-off, and automatically restarts and resumes operation when recovery conditions such as brake pedal release and / or accelerator pedal depressing are met. The idle stop control CTspidl includes First Idling Stop (FIS) and Stop and Start (S&S). The First Idling Stop (FIS) is a control that keeps the engine 12 in a standby state where it is not running when the vehicle 10 is powered on but not in motion. The Stop and Start (S&S) is a control that temporarily stops the running engine 12 while the vehicle 10 is moving or stationary. The Stop and Start (S&S) is a normal idle stop control. The power supply state of the vehicle 10 is the ignition-on state (“IG-ON”) described later.

[0042] The second starting device 18 includes a starter motor 32 and a low-voltage battery 34. The starter motor 32 is a motor configured to drive the engine 12 to rotate. The starter motor 32 is driven by electricity supplied from the low-voltage battery 34. The low-voltage battery 34 is an energy storage device that supplies electricity to the starter motor 32. The starter motor 32 is a starting motor used to start the engine 12. In other words, the starter motor 32 is a dedicated motor that drives the engine 12 to rotate when the engine 12 is started, thus starting the engine 12. The second starting device 18 is a starting device that uses the starter motor 32 to start the engine 12.

[0043] The DC-DC converter 20 is connected to the high-voltage battery 26. The DC-DC converter 20 charges the low-voltage battery 34 and / or supplies power to the electrical load 22 by stepping down the voltage of the high-voltage battery 26. The low-voltage battery 34 is connected to the DC-DC converter 20 and is charged by the DC-DC converter 20 using power supplied from the high-voltage battery 26 as a source. The low-voltage battery 34 is a low-voltage power supply device configured to be charged by the high-voltage battery 26 and to supply power to the starter motor 32. The high-voltage battery 26 is a high-voltage battery that stores electricity at a voltage higher than that of the low-voltage battery 34, and is a high-voltage power supply device configured to charge the low-voltage battery 34. The high-voltage battery 26 is, for example, a lithium-ion battery, a nickel-metal hydride battery, or other secondary battery. The low-voltage battery 34 is, for example, a lead-acid battery or other secondary battery.

[0044] Electrical load 22 refers to various electrical devices that operate using power supplied from a low-voltage power source such as low-voltage battery 34. Examples of electrical load 22 include windshield wipers, blower motors, and navigation systems. Although not shown in the diagram, the power used to operate various ECUs (Electronic Control Units) such as the electronic control device 70 described later is also supplied by the low-voltage battery 34.

[0045] The start button 24 is a power switch operated by the driver to switch the power supply state in the vehicle 10, i.e., the vehicle power state. The start button 24 is, for example, a momentary push-button switch, pressed by the driver to the on position. Each time the start button 24 is pressed to the on position, it outputs a power switch signal PSon corresponding to that position to the electronic control unit 70 (described later). The electronic control unit 70 detects the driver's operation of the start button 24 based on the power switch signal PSon.

[0046] The vehicle's power supply states include, for example, an ignition-off state ("IG-OFF"), an auxiliary equipment-on state ("ACC"), and an ignition-on state ("IG-ON"). The "IG-OFF" state, for example, is a power supply state used to prevent the vehicle from moving and also to disable some functions unrelated to vehicle movement; it is a power-off state for vehicle 10. The "ACC" state, for example, is a power supply state used to turn off the instrument cluster (not shown) to prevent the vehicle from moving but to enable some functions unrelated to vehicle movement; it is a power-on state for vehicle 10. The "IG-ON" state, for example, is a power supply state used to illuminate the instrument cluster to enable the vehicle to move; it is a power-on state for vehicle 10.

[0047] The vehicle 10 also includes an electronic control unit 70 that includes control devices for the vehicle 10. The electronic control unit 70 is configured to include a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, and input / output interfaces. The CPU utilizes the temporary storage function of RAM and performs signal processing according to a program pre-stored in the ROM, thereby executing various controls of the vehicle 10. The electronic control unit 70 may include various computers for engine control, transmission control, etc., as needed.

[0048] The electronic control unit 70 is supplied with various signals based on the detection values ​​of various sensors (such as DC-DC converter 20, start button 24, engine speed sensor 50, MG speed sensor 52, vehicle speed sensor 54, accelerator opening sensor 56, throttle opening sensor 58, brake switch 60, etc.) of the vehicle 10. These signals include (e.g., DC-DC power supply voltage VLdc, power switch signal PSon, engine speed Ne as the speed of engine 12, MG speed Nm as the speed of electric motor MG, vehicle speed V, accelerator opening θacc as the amount of driver's accelerator operation indicating the magnitude of driver's acceleration operation, throttle opening θth as the opening of electronic throttle, brake activation signal Bon as a signal indicating the state of the brake pedal operated by the driver to activate the wheel brakes).

[0049] The DC-DC power supply voltage VLdc is the output voltage of the DC-DC converter 20, which is supplied to the low-voltage battery 34 after stepping down the voltage of the high-voltage battery 26. It represents the output voltage of the low-voltage battery 34. The DC-DC converter 20 is configured to include, for example, a dedicated ECU that has the function of detecting the DC-DC power supply voltage VLdc. Based on the detection value of the low-voltage battery sensor 62 provided in the vehicle 10, the temperature of the low-voltage battery 34 (THlowb) and the charging / discharging current of the low-voltage battery 34 (Ilowb) are supplied to the DC-DC converter 20.

[0050] The DC-DC converter 20 calculates the state of charge (SOC) of the low-voltage battery 34 based, for example, on the cumulative value of the low-voltage battery charging / discharging current Ilowb. The SOC represents the state of charge of the low-voltage battery 34, i.e., the state of charge value, and represents the ratio of remaining charge capacity to full charge capacity, i.e., the charge rate. The maximum output power of the low-voltage battery 34, i.e., the output power, is smaller, for example, in low-temperature regions where the low-voltage battery temperature THlowb is lower than the normal operating temperature. Furthermore, the output power of the low-voltage battery 34 is smaller, for example, in regions with low SOC, the lower the SOC. Alternatively, the low-voltage battery temperature THlowb and the low-voltage battery charging / discharging current Ilowb can be supplied to the electronic control device 70, and the electronic control device 70 can calculate the SOC.

[0051] The electronic control unit 70 outputs various command signals to the various devices (such as engine 12, automatic transmission 14, electric motor MG, DC-DC converter 20, starter motor 32, etc.) of the vehicle 10. These signals include engine control command signal Se for controlling engine 12, transmission control command signal Sat for controlling automatic transmission 14, MG control command signal Sm for controlling electric motor MG, DC-DC control command signal Sdc for controlling DC-DC converter 20, and starter control command signal Sst for controlling starter motor 32.

[0052] In order to realize various controls in the vehicle 10, the electronic control unit 70 includes an engine control unit, namely engine control unit 72, a transmission control unit, namely transmission control unit 74, and a start control unit, namely start control unit 76.

[0053] The engine control unit 72 calculates the driver's driving demand on the vehicle 10 by applying the accelerator opening θacc and vehicle speed V to a driving demand mapping. This driving demand mapping is a pre-determined relationship, either experimentally or in design. The driving demand is, for example, the required driving torque Trdem [Nm] of the drive wheels. The required driving force Frdem [N] of the drive wheels can also be used as the driving demand. The engine control unit 72 outputs an engine control command signal Se to the engine 12 to control the engine 12 in a manner that takes into account transmission losses, auxiliary machine loads, and the gear ratios of the automatic transmission 14 to achieve the required driving torque Trdem.

[0054] The transmission control unit 74 uses a predetermined shift mapping to determine the shift of the automatic transmission 14, and outputs a transmission control command signal Sat to the automatic transmission 14 as needed, i.e., based on the result of its shift determination. The shift mapping is, for example, a predetermined relationship on a two-dimensional coordinate system with vehicle speed V and required drive torque Trdem as variables, having shift lines for determining the shift of the automatic transmission 14.

[0055] The starting control unit 76 determines whether there is a starting request for the engine 12 that switches the operating state, i.e., the control state, of the engine 12 from a stopped state to an operating state. For example, the starting control unit 76 determines whether there is a starting request for the engine 12 based on whether the idle speed stop control FIS was not executed when the vehicle power supply was set to "IG-ON", or whether the idle speed stop control CTspidl was released during the execution of the idle speed stop control CTspidl, for example, by setting the brake on signal Bon to off. In this embodiment, the starting request for the engine 12 that accompanies the release of the idle speed stop control CTspidl is referred to as a restart request for the engine 12 when distinguished from the initial starting request for the engine 12 that accompanies the change from "IG-OFF" to "IG-ON" of the vehicle power supply.

[0056] When the starting control unit 76 determines that there is a starting request for the engine 12, it essentially performs the starting operation using the first starting device 16. Specifically, when the starting control unit 76 determines that there is a starting request for the engine 12, it outputs an MG control command signal Sm to the electric motor MG to output the starting torque Tcr. The starting control unit 76, in conjunction with the starting operation of the engine 12 based on the electric motor MG, outputs an engine control command signal Se to the engine 12 to start fuel supply, engine ignition, etc. The starting torque Tcr is a predetermined torque required to start the engine 12 and increase the engine speed Ne. The starting torque Tcr is, for example, a certain torque predetermined based on the specifications of the engine 12.

[0057] Here, when the engine 12 is started, for example when the discharge capacity of the high-voltage battery 26 is small or it is difficult to supply power from the high-voltage battery 26, it is difficult to properly control the electric motor MG. Therefore, for example, when the vehicle 10 is in a predetermined extremely low temperature environment where it is determined that the electric motor MG cannot be properly controlled, it is sometimes difficult to start the engine 12 based on the start-up using the first starting device 16.

[0058] When the engine 12 is started, if the vehicle 10 is in a predetermined extremely low temperature environment where the electric motor MG cannot be properly controlled, the starting control unit 76 will use the second starting device 18 instead of the first starting device 16. Specifically, when the starting control unit 76 determines that there is a starting requirement for the engine 12, and the vehicle 10 is in a predetermined extremely low temperature environment, it will output a starter control command signal Sst to the starter motor 32 to start the engine 12 based on the starter motor 32. The starting control unit 76, in conjunction with the engine 12 starting based on the starter motor 32, will output an engine control command signal Se to the engine 12 to start fuel supply, engine ignition, etc. When the engine 12 is in a completely detonated state, the starting control unit 76 will release the starter control command signal Sst and stop the starting based on the starter motor 32.

[0059] Thus, when starting the engine 12, the starting control unit 76 prioritizes starting the engine 12 using the first starting device 16 over starting the engine 12 using the second starting device 18. In other words, in starting the engine 12 during the transition from "IG-OFF" to "IG-ON" of the vehicle power supply, and in starting the engine 12 during the release of the idle stop control CTspidl, starting the engine 12 using the first starting device 16 is prioritized. On the other hand, in extremely low temperature environments, starting the engine 12 using the second starting device 18 instead of the first starting device 16 is performed. Furthermore, when starting the engine 12 for the first time during the transition from "IG-OFF" to "IG-ON" of the vehicle power supply, since the starting torque Tcr required by the engine 12 before preheating tends to increase, starting the engine 12 using the second starting device 18 can also be performed.

[0060] When starting the engine 12, starting using the first starting device 16 may fail. If starting using the first starting device 16 fails, the starting control unit 76 performs starting the engine 12 using the second starting device 18. In this way, starting the engine 12 using the second starting device 18 has a backup function for starting the engine 12.

[0061] Since starting the engine using the second starting device 18 serves as a backup function, it is preferable not to execute the idle speed stop control CTspidl if starting the engine 12 using the second starting device 18 cannot be guaranteed. The starting control unit 76 allows the idle speed stop control CTspidl if starting the engine 12 using the second starting device 18 can be guaranteed. On the other hand, the starting control unit 76 prohibits the idle speed stop control CTspidl if starting the engine 12 using the second starting device 18 cannot be guaranteed.

[0062] If the low-voltage battery 34 is in good condition, the starting of the engine 12 using the second starting device 18 can be guaranteed. The starting control unit 76 determines whether to allow the idle stop control CTspidl based on whether the state of the low-voltage battery 34 is sufficient to guarantee the starting of the engine 12 using the starter motor 32. The state of the low-voltage battery 34 is represented by its deterioration state, its state of charge (SOC), etc. The state of the low-voltage battery 34 can be determined, for example, based on the output voltage of the low-voltage battery 34 when the engine 12 using the second starting device 18 is successfully started, i.e., the DC-DC power supply voltage VLdc, or the starter start voltage VLst. The starter start voltage VLst is the DC-DC power supply voltage VLdc during the transition of the starter motor 32's rotation at the point when the engine 12 using the second starting device 18 is successfully started. In other words, the voltage VLst when the starter is started is, for example, the DC-DC power supply voltage VLdc at the time when the engine 12 is completely detonated and the engine 12 has started to rotate.

[0063] Figure 2 This is a diagram illustrating an example of the starter voltage VLst during engine 12 starting using the second starting device 18. Figure 2 In this context, time point t1 represents the time when the engine 12 starts running using the second starting device 18, i.e., the time when the starter motor 32 begins to drive. When the starter motor 32 begins to drive, the DC-DC power supply voltage VLdc decreases from the open circuit voltage OCV. When the engine 12 starts successfully and the starter motor 32 stops driving, the DC-DC power supply voltage VLdc rises towards the open circuit voltage OCV (referring to time point t2 and later). The DC-DC power supply voltage VLdc at the time when the engine 12 starts successfully, i.e., the time when the starter motor 32 stops driving, is the starter voltage VLst (referring to time point t2). The open circuit voltage OCV is the voltage between the terminals of the low-voltage battery 34 when no load is applied to the low-voltage battery 34.

[0064] return Figure 1The starting control unit 76 uses the voltage VLst when the starter is started and the charge amount SOC of the low-voltage battery 34 to determine whether the low-voltage battery 34 is in good condition, and determines whether to allow the idle stop control CTspidl based on whether the low-voltage battery 34 is in good condition.

[0065] The conditions under which CTspidl (Idle Stop Control) is permitted include: the case where the vehicle power supply is allowed to be switched from "IG-OFF" to "IG-ON" during the next trip without starting, and the case where the vehicle power supply is allowed to be switched from "IG-ON" to "IG-ON" during the next trip after starting. The FIS (Idle Stop Control) permission determination for the non-starting idle stop control FIS and the S&S (Idle Stop Control) permission determination for the starting idle stop control S&S can be performed separately. When the FIS permission determination result is "permitted," the FIS permission flag becomes active; when the FIS permission determination result is "disallowed," the FIS permission flag becomes inactive. Similarly, when the S&S permission determination result is "permitted," the S&S permission flag becomes active; when the S&S permission determination result is "disallowed," the S&S permission flag becomes inactive.

[0066] The FIS (Free Idle Speed ​​Control) permission determination result is the result of the permission determination for the idle stop control FIS (Free Idle Speed ​​Control) during the next trip when the vehicle 10 is not started. Therefore, when the power supply to the vehicle 10 is disconnected, that is, when the vehicle power supply is set to "IG-OFF", the start control unit 76 stores the permission determination result of the idle stop control CTspidl, especially the FIS permission determination result, in a non-volatile memory, for example. Even when the vehicle power supply is set to "IG-OFF", some parts of various ECUs, such as the electronic control unit 70, continue to operate for a certain period of time. In addition, even when the vehicle power supply is set to "IG-OFF", ECUs related to the detection functions of safety functions, vehicle key, etc., continue to operate. Furthermore, the start control unit 76 may also store the S&S (Free Slow and Slow Speed ​​Control) permission determination result in a non-volatile memory, for example, when the vehicle power supply is set to "IG-OFF". Alternatively, the start control unit 76 may also set the S&S permission flag to active when the vehicle power supply is set to "IG-OFF", that is, the S&S permission flag is active by default.

[0067] However, even when the vehicle power is set to "IG-OFF", the state of charge (SOC) of the low-voltage battery 34 will decrease due to discharge caused by standby power and other factors. Therefore, if the vehicle power is set to "IG-ON" and the permission determination for the idle stop control FIS (free-running system) stored from the previous trip is used, the idle stop control FIS may be incorrectly enabled when the vehicle is not in motion.

[0068] The idle speed stop control FIS when not in motion preferably begins after a preparation period TRp, which is the period from the time the vehicle power is set to "IG-ON" until a predetermined time TMf is executed after the initialization process of various ECUs such as the electronic control unit 70. Therefore, after the preparation period TRp, it is necessary to determine the permission for the idle speed stop control FIS when not in motion. The initialization process is, for example, a known initialization process in computers.

[0069] During the period when the vehicle power supply is set to "IG-OFF", the DC-DC converter 20 is not operating, therefore, the cumulative value of the low-voltage battery charge / discharge current Ilowb is unknown. During the short preparation period TRp, it is difficult to determine the state of charge (SOC) by not using the cumulative value of the low-voltage battery charge / discharge current Ilowb.

[0070] Alternatively, the following method could be considered: During the preparation period (TRp), for example, driving the starter motor 32 while the engine 12 cannot be driven to rotate, even if the starter motor 32 is idling, and detecting the voltage VLst when the starter is started to determine the permission for the idle stop control FIS when not in motion. However, in the method of allowing the starter motor 32 to idle, there is a possibility that the voltage drop of the DC-DC power supply voltage VLdc may cause various ECUs to be reset, and the initialization process of various ECUs to be redone, resulting in a longer initialization process. Moreover, there is a possibility that after the vehicle power supply is just set to "IG-ON", the voltage drop of the high-voltage battery 26 caused by the DC-DC converter 20 is unstable, and the voltage drop of the DC-DC power supply voltage VLdc caused by the operation of the starter motor 32 is large, making it easy for various ECUs to be reset. Furthermore, the idle stop control FIS when not in motion aims to achieve quietness and fuel consumption reduction by stopping the engine 12, but the operation of the starter motor 32 may impair the quietness.

[0071] Therefore, the starting control unit 76 extrapolates the state of the low-voltage battery 34 after "IG-ON" by adding the discharge amount of the low-voltage battery 34 during the "IG-OFF" period to the "IG-ON" state based on the ECU voltage passivation value VLse of TRp during the preparation period. The starting control unit 76 uses the FIS allowance determination result using the ECU voltage passivation value VLse and the FIS allowance determination result stored during the "IG-OFF" period of the previous trip to determine the FIS allowance determination for the "IG-ON" period of the current trip. The ECU voltage passivation value VLse is the voltage passivation value obtained by performing passivation treatment on the DC-DC power supply voltage VLdc during the preparation period.

[0072] Specifically, during the preparation period TRp, the start control unit 76 calculates the ECU voltage passivation value VLse using the following formula (1) for each predetermined control cycle. In the following formula (1), "VLse(n)" is the ECU voltage passivation value VLse calculated in the current control cycle. "VLse(n-1)" is the ECU voltage passivation value VLse calculated in the previous control cycle. "VLdc" is the DC-DC power supply voltage VLdc detected in the current control cycle. "S" is a predetermined passivation amount greater than 1. The start control unit 76 sets "VLse(n)" calculated at the time point after the preparation period TRp as the ECU voltage passivation value VLse for FIS permission determination. The ECU voltage passivation value VLse is used to calculate the ECU voltage passivation value VLse by, for example, using a value that smooths the change in DC-DC power supply voltage VLdc in a short period immediately after "IG-ON", thereby suppressing erroneous determinations of FIS permission.

[0073] VLse(n)=VLse(n-1)+(VLdc-VLse(n-1)) / S...(1)

[0074] In Equation (1), for example, a predetermined voltage value above the open-circuit voltage OCV of the low-voltage battery 34 is preset as the initial value of the ECU voltage passivation value VLse, that is, the value set to "VLse(n-1)" in the initial calculation using Equation (1). This is to suppress the inrush current caused by the capacitor component immediately after "IG-ON" and the voltage drop caused by the operation of various ECUs, etc., which could lead to incorrect determination of the FIS allowance. In this way, the starting control unit 76 sets the voltage value above the open-circuit voltage OCV as the initial value of the ECU voltage passivation value VLse and begins the passivation process of the DC-DC power supply voltage VLdc in TRp during the preparation period.

[0075] The starting control unit 76 determines whether the allowance result of the idle stop control CTspidl, especially the FIS allowance result, stored when the vehicle power supply was "IG-ON" and the vehicle power supply was "IG-OFF" is allowed. Additionally, the starting control unit 76 determines whether the ECU voltage passivation value VLse is above the predetermined voltage VLsef that ensures the starting of the engine 12. When the ECU voltage passivation value VLse is low, that is, when the state of charge (SOC) of the low-voltage battery 34 is low (which can be inferred by analogy), the output power of the low-voltage battery 34 decreases, making it difficult to restart the idle stop control FIS from a standstill. The predetermined voltage VLsef is, for example, a predetermined threshold used to ensure the restart of the idle stop control FIS from a standstill.

[0076] The starting control unit 76, when the vehicle power supply is "IG-ON", if it determines that the FIS permission determination result stored during the last "IG-OFF" period of the vehicle power supply is permitted, and if it determines that the ECU voltage passivation value VLse is above the predetermined voltage VLsef, then it permits the idle stop control CTspidl, especially the idle stop control FIS when the vehicle is not started. Permitting the idle stop control FIS when the vehicle is not started means setting the FIS permission determination to permitted and setting the FIS permission flag to active.

[0077] The starting control unit 76, when the vehicle power supply is "IG-ON", if it determines that the FIS permission determination result stored during the last "IG-OFF" period of the vehicle power supply is not allowed, or if it determines that the ECU voltage passivation value VLse is lower than the predetermined voltage VLsef, then it does not allow the idle stop control FIS when the vehicle is not started. Disallowing the idle stop control FIS when the vehicle is not started means setting the FIS permission determination to not allow and deactivating the FIS permission flag.

[0078] When the starting control unit 76 does not allow idle stop control FIS before starting, it outputs an initial starting request for the engine 12. At this time, starting the engine 12 using the first starting device 16 can be considered. Since it is unclear whether starting the engine 12 using the second starting device 18 can be guaranteed, it is preferable to also prohibit idle stop control S&S after starting. On the other hand, if the initial starting of the engine 12 is performed using the engine 12 with the second starting device 18, it can be confirmed whether starting the engine 12 using the second starting device 18 can be guaranteed. Therefore, when the starting control unit 76 does not allow idle stop control FIS before starting, it does not prohibit idle stop control S&S after starting, and sets the initial starting request for the engine 12 to be a starting request based on starting the starter motor 32, i.e., an initial starter start request. In other words, when the vehicle power supply is "IG-ON", the start control unit 76 maintains the state of activating the S&S permission flag and performs the start-up of the engine 12 using the starter motor 32 if the FIS permission determination result stored when the vehicle power supply was "IG-OFF" is not allowed, or if the ECU voltage passivation value VLse is lower than the predetermined voltage VLsef.

[0079] When starting the engine 12 using the starter motor 32, the starting control unit 76 determines whether to allow idle stop control CTspidl, and especially idle stop control S&S after starting, based on whether the voltage VLst at starter start is above a second predetermined voltage VLstf that can guarantee the starting of the engine 12. The second predetermined voltage VLstf is, for example, a predetermined threshold used to determine whether the condition of the low-voltage battery 34 is good enough to guarantee the starting of the engine 12 using the second starting device 18, and is set to a value lower than the predetermined voltage VLsef.

[0080] Specifically, when the voltage VLst is above the second predetermined voltage VLstf during start-up, the starter control unit 76 maintains the S&S enable flag active. In this case, the starter control unit 76 may also switch the FIS enable flag from inactive to active. On the other hand, when the voltage VLst is below the second predetermined voltage VLstf during start-up, the starter control unit 76 switches the S&S enable flag to inactive.

[0081] When the low-voltage battery temperature Thlowb is low during the "IG-ON" phase of this trip, the output power of the low-voltage battery 34 decreases, potentially making it difficult to restart the idle stop control FIS from a standstill. Therefore, the start control unit 76 can also determine whether the low-voltage battery temperature Thlowb is above a predetermined temperature Thlowbf that ensures the starting of the engine 12. The predetermined temperature Thlowbf is, for example, a predetermined threshold used to ensure the restart of the idle stop control FIS from a standstill.

[0082] Alternatively, when the vehicle power supply is "IG-ON", the starting control unit 76, based on determining that the ECU voltage passivation value VLse is above or above the predetermined voltage VLsef, and determining that the low-voltage battery temperature THlowb is above or above the predetermined temperature THlowbf, may allow idle stop control CTspidl, especially idle stop control FIS when not in motion. The starting control unit 76 may also, when the vehicle power supply is "IG-ON", disallow idle stop control FIS when not in motion if it determines that the low-voltage battery temperature THlowb is below the predetermined temperature THlowbf.

[0083] Figure 3 and Figure 4 The flowcharts are respectively the main parts of the control operation of the electronic control device 70, and the flowcharts are for the control operation of suppressing the loss of the opportunity to execute the idle stop control CTspidl and suppressing the false permission of the idle stop control CTspidl, for example, when it is executed while driving. Figure 3 This is a flowchart that was executed during the last trip. Figure 4This is the flowchart for the process executed during this trip. Furthermore, for convenience, the execution... Figure 3 The time of the journey relative to the execution Figure 4 The current schedule is set to the last schedule, but it is currently in progress. Figure 3 This was during this trip.

[0084] exist Figure 3 In this flowchart, each step corresponds to the function of the starting control unit 76. The permission determination for starting idle stop control CTspidl in the previous trip is performed. In step S10 (hereinafter, "step"), the condition of the low-voltage battery 34 is determined based on the starter voltage VLst and the state of charge (SOC) of the low-voltage battery 34. Based on the condition of the low-voltage battery 34, the FIS permission determination for the next trip is performed. Next, in S20, it is determined whether the vehicle power supply is set to "IG-OFF". If the determination in S20 is negative, S10 is executed. If the determination in S20 is positive, in S30, the FIS permission determination result from S10 is stored in a non-volatile memory or the like.

[0085] exist Figure 4 In this process, each step of the flowchart corresponds to the function of the starting control unit 76. After the vehicle power is "IG-ON" in this trip, the ECU voltage passivation value VLse is calculated before the preparation period TRp. Then, in S40, it is determined whether the FIS permission determination result stored in the previous trip is permitted. If the determination in S40 is yes, in S50, it is determined whether the low-voltage battery temperature THlowb is above the predetermined temperature THlowbf and the ECU voltage passivation value VLse is above the predetermined voltage VLsef. If the determination in S50 is yes, in S60, the FIS permission determination is set to permitted, the FIS permission flag is activated, and the permission determination of the idle stop control CTspidl ends. The S&S permission flag is kept active. If the determination in S40 is no, or if the determination in S50 is no, in S70, the FIS permission determination is set to disallowed, the FIS permission flag is deactivated, and the initial starter start request is output. At this point in time, the S&S allow flag remains active. Next, in S80, it is determined whether the starter voltage VLst is above the second predetermined voltage VLstf. If the determination in S80 is yes, in S90, the S&S allow flag remains active, and the allowance determination for the idle stop control CTspidl ends. In this case, the FIS allow flag can also be switched from inactive to active. If the determination in S80 is no, the S&S allowance determination is set to disallowed, the S&S allow flag is deactivated, and the allowance determination for the idle stop control CTspidl ends.

[0086] As described above, according to this embodiment, when the vehicle power supply is "IG-ON", if the allowed determination result of the idle stop control CTspidl stored during the previous "IG-OFF" period is allowed, and the ECU voltage passivation value VLse is above the predetermined voltage VLsef, then the idle stop control CTspidl is allowed. Therefore, regardless of the length of the period from the previous "IG-OFF" time point to the current "IG-ON" time point, the current state of the low-voltage battery 34, including the discharge of the low-voltage battery 34, can be inferred from the ECU voltage passivation value VLse. By comparing the allowed determination result of the idle stop control CTspidl using the ECU voltage passivation value VLse with the allowed determination result of the idle stop control CTspidl stored during the previous "IG-OFF" period, the accuracy of the allowed determination of the idle stop control CTspidl during the current "IG-ON" period can be ensured. Thus, the loss of opportunity to execute the idle stop control CTspidl can be suppressed, and the false allowance of the idle stop control CTspidl can be suppressed. By suppressing the false permission of the idle stop control CTspidl, it is possible to suppress the situation where the engine 12 is difficult to restart from the idle stop control CTspidl.

[0087] Furthermore, according to this embodiment, when the vehicle power supply is "IG-ON", if the allowed determination result of the idle stop control CTspidl stored during the previous "IG-OFF" period of the vehicle power supply is not allowed, or if the ECU voltage passivation value VLse is lower than the predetermined voltage VLsef, the idle stop control CTspidl is not allowed, thus suppressing the false allowance of the idle stop control CTspidl. At this time, when starting using the starter motor 32 is performed, the allowance of the idle stop control CTspidl is determined again based on whether the voltage VLst when the starter is started is higher than the second predetermined voltage VLstf, thus suppressing the loss of the opportunity to execute the idle stop control CTspidl.

[0088] Furthermore, according to this embodiment, the idle stop control CTspidl that stores the permission determination result when "IG-OFF" is the idle stop control FIS when not started, and the idle stop control CTspidl that performs the permission determination when "IG-ON" is the idle stop control FIS when not started. Therefore, it is possible to suppress the loss of opportunity to execute the idle stop control FIS when not started, and to suppress the false permission of the idle stop control FIS when not started. In addition, the idle stop control CTspidl that does not allow the idle stop control FIS when not started when "IG-ON" but performs the permission determination when starting using the starter motor 32 is the idle stop control S&S after start-up. Therefore, it is possible to suppress the loss of opportunity to execute the idle stop control S&S after start-up.

[0089] Furthermore, according to this embodiment, the voltage value above the open circuit voltage OCV of the low-voltage battery 34 is set as the initial value of the ECU voltage passivation value VLse. During the preparation period, the passivation treatment of the DC-DC power supply voltage VLdc in TRp is performed. Therefore, it is possible to suppress the situation where the allowable determination of the idle stop control CTspidl is mistakenly made due to the surge current caused by the capacitor component immediately after "IG-ON" and the voltage drop caused by the operation of various ECUs.

[0090] Furthermore, according to this embodiment, during "IG-ON", when the ECU voltage passivation value VLse is above the predetermined voltage VLsef and the low-voltage battery temperature THlowb is above the predetermined temperature THlowbf, the idle stop control CTspidl is allowed. Therefore, by taking into account the low-voltage battery temperature Thlowb, which affects the output power of the low-voltage battery 34, the accuracy of the determination of the allowable idle stop control CTspidl during this "IG-ON" can be appropriately ensured.

[0091] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention may also be applied in other ways.

[0092] For example, in the foregoing embodiments Figure 4 In the flowchart, if only FIS allowance determination is performed, then S70-S90 can be omitted. Alternatively, in S50, it is sufficient to determine whether the ECU voltage passivation value Vlse is above the predetermined voltage VLsef, and it is not necessary to determine whether the low-voltage battery temperature Thinkb is above the predetermined temperature THlowbf. Thus, Figure 4 The flowchart can be modified appropriately.

[0093] In addition, in the aforementioned embodiments, the idle stop control CTspidl includes the idle stop control S&S after starting and the idle stop control FIS when not starting. If only the FIS permission determination is performed, then at least the idle stop control FIS when not starting is required.

[0094] Furthermore, in the aforementioned embodiments, vehicle 10 may also be a series hybrid vehicle, etc., and does not necessarily need to have an automatic transmission 14. Additionally, vehicle 10 has a first starting device 16 and a second starting device 18, but at least the second starting device 18 is sufficient. If vehicle 10 only has the second starting device 18, it can have a known alternator driven by engine 12 to generate electricity as a device for charging the low-voltage battery 34, and does not need to have a DC-DC converter 20.

[0095] Furthermore, the above description is merely one implementation method, and the present invention can be implemented in various ways with modifications and improvements based on the knowledge of those skilled in the art.

Claims

1. A control device for a vehicle, the vehicle comprising an engine and a starting device, the starting device having a motor configured to drive the engine to rotate and an energy storage device for supplying power to the motor, the motor being used to start the engine, the control device characterized in that it includes a starting control unit, the starting control unit, Based on whether the state of the energy storage device is such that the engine can be started by the start-up mechanism, it is determined whether idle stop control, which temporarily stops the engine, is allowed. Furthermore, when the vehicle's power is disconnected, the determination result of allowing idle stop control is stored. On the other hand... When the vehicle's power is turned on, if the permission determination result of the idle stop control stored at the last time the power was turned off is allowed, and the voltage passivation value after passivation processing of the output voltage of the energy storage device during the period from the time the power is turned on to the time when the initialization process of the control device is executed is above the predetermined voltage that can guarantee the starting of the engine, then the idle stop control is allowed.

2. The vehicle control device according to claim 1, characterized in that, The starting control unit, when the power is turned on, if the allowed determination result of the idle speed stop control stored when the power was last turned off is not allowed, or if the voltage passivation value is lower than the predetermined voltage, does not allow the idle speed stop control, and then performs the starting operation using the motor. The starting control unit determines whether to allow the idle stop control based on whether the output voltage of the energy storage device during the start-up transition is above a second predetermined voltage that is set to a value lower than the predetermined voltage and can ensure the start of the engine.

3. The vehicle control device according to claim 2, characterized in that, The idle stop control includes idle stop control when the vehicle is not started and idle stop control after the vehicle has started. The idle stop control when the vehicle is not started prevents the engine from starting when the power is on and the vehicle is not in motion, keeping it in a standby state. The idle stop control after the vehicle has started temporarily stops the running engine while the vehicle is in motion or stationary. The idle stop control that stores the permission determination result when the power is disconnected is the idle stop control when the engine is not started. The idle stop control that performs the permission determination when the power is turned on is the idle stop control when the engine is not running. The idle stop control that is not allowed when the power is turned on but is allowed when the motor is started is the idle stop control after starting.

4. The vehicle control device according to any one of claims 1 to 3, characterized in that, The start-up control unit sets a voltage value above the open-circuit voltage of the energy storage device as the initial value of the voltage passivation value and begins the passivation process.

5. The vehicle control device according to any one of claims 1 to 3, characterized in that, When the power is turned on, the starting control unit allows the idle speed stop control if the voltage passivation value is above the predetermined voltage and the temperature of the energy storage device is above the predetermined temperature that can guarantee the starting of the engine.

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