Vehicle control device

Abstract

The present application achieves smooth vehicle control without causing discomfort to the occupant. A vehicle control device (11) has: an engine control section (63) that performs IS control in accordance with satisfaction of a prescribed stop condition, and engine restart control in accordance with satisfaction of a prescribed restart condition; a steep slope gentle descent control section that, during travel of the host vehicle on a downhill road and in the event that a deceleration control request related to HDC control is generated, performs deceleration control based on a target vehicle speed VStg regardless of a brake operation by a driver of the host vehicle; and an information acquisition section (61) that acquires information on a progress condition including a start and an end of the engine restart control. In the event that an engine restart request related to the IS control and a deceleration control request related to the HDC control are generated overlapping in time, the engine control section prioritizes the engine restart control, and the steep slope gentle descent control section permits execution of deceleration control based on the target vehicle speed VStg based on the progress condition including the start and the end of the engine restart control.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle control device having an idle stop function, which is a function of stopping an engine that is a drive source of a host vehicle when a prescribed stop condition is satisfied. BACKGROUND

[0002] In the past, a vehicle control device having an idle stop function, which is a function of stopping an engine that is a drive source of a host vehicle when a prescribed stop condition (for example, vehicle speed is zero and brake is on) is satisfied, has been known as a target of saving fuel, reducing electromagnetic interference, reducing vibration noise, and the like. In the following description, "idle stop" is sometimes abbreviated as "IS".

[0003] As one example of the above-described vehicle control device, in Patent Literature 1, there is disclosed an invention of a vehicle control device having: an IS control portion that stops an engine in accordance with establishment of a prescribed stop condition, and performs engine restart control in accordance with establishment of a prescribed restart condition after the engine is stopped; a steep slope gentle descent control portion that performs speed control in such a manner that a target vehicle speed VStg is not exceeded regardless of a driver's brake operation in traveling on a downhill road; and a steep slope gentle descent control setting portion that sets an active state and an inactive state of the steep slope gentle descent control portion. In the following description, "steep slope gentle descent" is sometimes abbreviated as "HDC".

[0004] In the vehicle control device of Patent Literature 1, there is a possibility that a situation in which an engine restart request related to IS control and a speed control (deceleration control) request related to HDC control overlap in time occurs. In this case, both the engine restart request related to IS control and the deceleration control request related to HDC control require relatively large electric power in response to each request. Therefore, in the situation in which the engine restart request related to IS control and the deceleration control request related to HDC control overlap in time, there is a concern that the request of one side cannot be responded to, and a passenger feels discomfort.

[0005] For example, if the engine is stopped by IS control in HDC control, downhill performance achieved by HDC control in the course of the downhill road cannot be sufficiently exerted.

[0006] Therefore, in the vehicle control device of Patent Literature 1, the IS control portion adopts a configuration in which the stop of the engine is prohibited in a case where HDC control is set to the active state.

[0007] According to the vehicle control device of Patent Literature 1, it is possible to achieve IS control and HDC control at the same time.

[0008] PRIOR ART DOCUMENTS

[0009] Patent Literature

[0010] Patent Literature 1: Japanese Patent Application Laid-Open No. 2020-012434 SUMMARY

[0011] However, in the vehicle control device of Patent Literature 1, in a scenario in which an engine restart request related to IS control and deceleration control request related to HDC control overlap in time, one of IS control and HDC control is exclusively executed, and thus, in a case where the deceleration control request related to HDC control is responded to, the engine restart request related to IS control cannot be responded to. As a result, for the vehicle control device of Patent Literature 1, there is a concern that a passenger can feel discomfort.

[0012] The present application has been made in view of the above-described circumstances, and has an object to provide a vehicle control device capable of achieving smooth vehicle control without causing a passenger to feel discomfort even in a scenario in which an engine restart request related to IS control and deceleration control request related to HDC control overlap in time.

[0013] To achieve the above object, a vehicle control device according to an embodiment of the present application is characterized by including: an engine control portion that performs idling stop control of stopping driving of an engine that is a drive source of a host vehicle in accordance with satisfaction of a prescribed stop condition, and that performs engine restart control in accordance with satisfaction of a prescribed restart condition; a steep slope gentle descent control portion that performs deceleration control based on a target vehicle speed that is set in advance in a case where the host vehicle is running on a downhill road and a deceleration control request related to steep slope gentle descent control is generated, regardless of a brake operation by a driver of the host vehicle; and an information acquisition portion that acquires information on a progress state including start and end of the engine restart control, wherein the engine control portion gives priority to the engine restart control in a case where an engine restart request related to the idling stop control and the deceleration control request related to the steep slope gentle descent control overlap in time, and the steep slope gentle descent control portion allows execution of the deceleration control based on the target vehicle speed based on the acquired information on the progress state including the start and the end of the engine restart control.

[0014] EFFECT OF THE INVENTION

[0015] The vehicle control device according to the embodiment of the present application can achieve smooth vehicle control without causing a passenger to feel discomfort even in a scenario in which an engine restart request related to IS control and deceleration control request related to HDC control overlap in time. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a configuration block diagram showing an outline of the vehicle control device of the embodiment of the present application.

[0017] Figure 2 is a flowchart for an action explanation of the vehicle control device for the embodiment of the present application.

[0018] Figure 3A is a timing chart for an action explanation of the vehicle control device for the case where the engine shifts to the knock state within the prescribed time from the start point of the engine restart control.

[0019] Figure 3B is a timing chart for an action explanation of the vehicle control device for the case where the engine does not shift to the knock state within the prescribed time from the start point of the engine restart control.

[0020] Figure 4 is a flowchart for an action explanation of the vehicle control device for the modification of the embodiment of the present application.

[0021] Explanation of Reference Numerals

[0022] 11 vehicle control device

[0023] 41 engine

[0024] 51 HDC-ECU (steep slope slow descent control section)

[0025] 53 ENG-ECU

[0026] 57 VSA-ECU (steep slope slow descent control section)

[0027] 61 information acquisition section

[0028] 63 engine control section (judgment section) DETAILED DESCRIPTION

[0029] Hereinafter, the vehicle control device of the embodiment of the present application will be described in detail with appropriate reference to the drawings.

[0030] Further, in the drawings shown below, common reference numerals are attached in principle between components having common functions or between components having mutually corresponding functions. In addition, the size and the shape of the components are sometimes deformed or exaggerated for the sake of explanation. Outline of the vehicle control device 11 of the embodiment of the present application

[0031] First, the outline of the vehicle control device 11 of the embodiment of the present application will be described with reference to Figure 1 Figure 1 is a configuration block diagram showing an outline of the vehicle control device 11 of the embodiment of the present application. ​

[0032] The vehicle control device 11 of the embodiment of the present application has a function of enabling smooth vehicle control that does not cause a passenger to feel discomfort even in a situation in which an engine restart request related to IS control and a deceleration control request related to HDC control are generated overlapping in time.

[0033] To achieve the above function, as shown in Figure 1 the vehicle control device 11 of the embodiment of the present application is configured such that the input-type elements 13 and the output-type elements 15 are connected in a manner enabling data communication therebetween, for example, via a communication medium 17 such as a CAN (Controller Area Network).

[0034] As shown in Figure 1 the configuration of the input-type elements 13 includes an ignition key switch (IG key switch) 21, a radar 23, a camera 25, a vehicle speed sensor 27, a wheel speed sensor 29, a brake pedal sensor 31, an accelerator pedal sensor 33, a brake hydraulic pressure sensor 35, an HDC start switch 37, and an MMI (Man-Machine Interface) 39.

[0035] On the other hand, as shown in Figure 1 the configuration of the output-type elements 15 includes an ACC (Adaptive Cruise Control)-ECU 50, an HDC (Hill Descent Control)-ECU 51, an ENG-ECU 53, an ESB (Electric Servo Brake)-ECU 55, and a VSA (Vehicle Stability Assist; VSA is a registered trademark)-ECU 57.

[0036] The IG key switch 21 is a switch that is operated when power is supplied to each of the electrical components mounted on the vehicle via a not-shown vehicle-mounted storage battery. If the IG key switch 21 is operated to be turned on, power is supplied to the ACC-ECU 50, the HDC-ECU 51, the ENG-ECU 53, the ESB-ECU 55, and the VSA-ECU 57, and these ECUs 50, 51, 53, 55, and 57 are respectively started.

[0037] The radar 23 has a function of irradiating a radar wave to a target object including another vehicle traveling in front of the host vehicle, and receiving a radar wave reflected by the target object, thereby acquiring distribution information of the target object including a distance from the target object and a direction of the target object.

[0038] As the radar 23, for example, a laser radar, a millimeter wave radar, a centimeter wave radar, an ultrasonic wave radar, or the like can be appropriately used. The radar 23 is provided in a lower portion of a front grill of the host vehicle or the like. Distribution information of an object obtained by the radar 23 is transmitted to the ACC-ECU 50 via the communication medium 17.

[0039] The camera 25 has an optical axis inclined to an obliquely lower portion of a front of the host vehicle, and has a function of capturing an image in a proceeding direction of the host vehicle. As the camera 25, for example, a CMOS (Complementary Metal Oxide Semiconductor) camera, a CCD (Charge Coupled Device) camera, or the like can be appropriately used. The camera 25 is provided on a central upper portion of a windshield of the host vehicle or the like. An image information of the proceeding direction of the host vehicle captured by the camera 25 is transmitted to the ACC-ECU 50 as an image signal generated by an interlaced scanning method such as NTSC (National Television Standards Committee) or the like via the communication medium 17.

[0040] The vehicle speed sensor 27 has a function of detecting a travel speed (vehicle speed) VS of the vehicle. Information of the vehicle speed VS detected by the vehicle speed sensor 27 is transmitted to the ESB-ECU 55 or the like via the communication medium 17.

[0041] The wheel speed sensor 29 has a function of detecting a rotational speed (wheel speed) of each wheel (not shown) provided on the host vehicle, respectively. Information of the wheel speed of each wheel detected by the wheel speed sensor 29 is transmitted to the VSA-ECU 57 via the communication medium 17.

[0042] The brake pedal sensor 31 has a function of detecting an operation amount and a torque of a brake pedal (not shown) implemented by the driver. Information of the operation amount and the torque of the brake pedal detected by the brake pedal sensor 31 is transmitted to the ESB-ECU 55 or the like via the communication medium 17.

[0043] The accelerator pedal sensor 33 has a function of detecting an operation amount of an accelerator pedal (not shown) implemented by the driver. Information of the operation amount of the accelerator pedal detected by the accelerator pedal sensor 33 is transmitted to the VSA-ECU 57 or the like via the communication medium 17.

[0044] The brake hydraulic pressure sensor 35 has a function of detecting a brake hydraulic pressure in a supply liquid path of a VSA device (vehicle behavior stabilizing device; not shown) in a brake hydraulic system. Information of the hydraulic pressure in the supply liquid path of the VSA device detected by the brake hydraulic pressure sensor 35 is transmitted to the ESB-ECU 55 or the like via the communication medium 17.

[0045] HDC start switch 37 is a switch operated by the occupant when the HDC control is set to the on state (activated). HDC start switch 37 is located, for example, around the driver's seat. HDC start switch 37 receives setting information from the occupant to set the HDC control to the on state or the off state, and outputs the received setting information to the vehicle control unit 11.

[0046] The MMI (Man-Machine Interface) 39 is used, for example, when inputting setting information for the Adaptive Cruise Control (ACC) function. The ACC function setting information input via the MMI 39 is transmitted to the ACC-ECU 50, etc., via the communication medium 17.

[0047] Next, let's explain. Figure 1 Output element 15 is shown.

[0048] The ACC-ECU50, belonging to output element 15, is a microcomputer consisting of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. This microcomputer operates as follows: it reads and executes programs and data stored in the ROM, performing various functions including information acquisition, ACC control, and LSF control.

[0049] The ACC-ECU50 acquires various information, including the distribution information of objects obtained by radar 23, the image information of the vehicle's direction of travel captured by camera 25, the vehicle speed VS information detected by vehicle speed sensor 27, and the setting information of ACC function input via ACC operation switch 81 belonging to MMI (Man-Machine Interface) 39.

[0050] In addition, while the vehicle speed VS is maintained within the set speed range, the ACC-ECU50 performs follow control (ACC control) including acceleration control and deceleration control in a manner that maintains the distance from the preceding vehicle to the set distance without the need for operation of the accelerator pedal and brake pedal.

[0051] Furthermore, when the vehicle's speed is lower than the set speed (e.g., 30 km / h) in traffic jams on highways, the ACC-ECU50 performs follow control (LSF control) that includes acceleration control and deceleration control, in a way that maintains the distance from the preceding vehicle at the set distance without the need for operation of the accelerator pedal and brake pedal.

[0052] The HDC-ECU 51 derives the gradient angle of the place where the host vehicle is present. More specifically, the HDC-ECU 51 derives the gradient angle of the road surface, for example, based on the acceleration in the stationary state obtained by subtracting the acceleration in the direction of travel obtained by differentiating the vehicle speed Vs detected by the vehicle speed sensor 27 from the acceleration output from an acceleration sensor (not shown).

[0053] In addition, the HDC-ECU 51 performs deceleration control in such a manner as to suppress the acceleration due to the downward gradient when the host vehicle is traveling on a downward slope. Such deceleration control is referred to as HDC (Hill Descent Control) control.

[0054] The HDC-ECU 51 transmits a deceleration control request for HDC control to the VSA-ECU 57 when the host vehicle is traveling on a downward slope and the HDC activation switch 37 is set to the on state. Thus, the HDC-ECU 51 cooperates with the VSA-ECU 57 to perform deceleration control based on the target vehicle speed VStg set in advance regardless of the brake operation by the driver of the host vehicle.

[0055] Further, the HDC-ECU 51 corresponds to a part of the "steep slope gentle descent control section" of the present application. In addition, the case where the HDC activation switch 37 is set to the on state corresponds to the case where a deceleration control request related to the steep slope gentle descent (HDC) control is generated.

[0056] The ENG-ECU 53 has an information acquisition section 61 and an engine control section 63.

[0057] The ENG-ECU 53 is composed of a microcomputer having a CPU, a ROM, a RAM, and the like. The microcomputer reads the program and data stored in the ROM and operates in such a manner as to perform the execution control of the various functions including the information acquisition function and the engine control function possessed by the ENG-ECU 53.

[0058] The information acquisition section 61 has a function of acquiring various information including the depression amount of the accelerator pedal, the depression amount of the brake pedal, the vehicle speed Vs of the host vehicle, the engine rotational speed NE, the power supply voltage Vbg of the vehicle-mounted storage battery, and the progress status including the start and end of engine restart control.

[0059] The engine control section 63 has a function of controlling the drive of the engine 41 in accordance with the depression amount of the accelerator pedal and the like. More specifically, the engine control section 63 controls a throttle valve (not shown) that adjusts the intake air amount of the engine 41, an injector (not shown) that injects fuel gas, an ignition plug (not shown) that ignites the fuel, and the like.

[0060] The engine control section 63 has an idling stop function of stopping the engine 41 that is a drive source of the host vehicle when a stop condition is satisfied. Here, as the "stop condition", for example, these conditions that the vehicle speed VS of the host vehicle is in a low speed region (vehicle speed VS < vehicle speed threshold value VSth), the brake pedal is depressed, and the accelerator pedal is not depressed are adopted.

[0061] The engine control section 63, in a case where the stop condition that is a trigger point of performing engine 41 stop control is satisfied, as a principle, considers that there is a driving intention of stopping the drive of the engine 41 and performs control of stopping the drive of the engine 41.

[0062] In addition, the engine control section 63 has a function of considering that an engine restart request is generated when a prescribed restart condition is satisfied and restarting the engine 41. Here, the "restart condition" can be, for example, a condition that the accelerator pedal is depressed and a condition that the foot is removed from the brake pedal.

[0063] Further, the engine control section 63 has a function of detecting a voltage fluctuation of a vehicle-mounted battery (power supply) that occurs with the engine restart and judging whether the power supply voltage recovers from a reduced state to a normal state.

[0064] In addition, the engine control section 63 has a function of judging whether an elapsed time from a start point of engine restart control exceeds a prescribed time.

[0065] Further, the engine control section 63 monitors the voltage fluctuation of the power supply, and in a case where the voltage value of the power supply increases from a prescribed voltage threshold value or less to exceed the voltage threshold value, makes a judgment that the voltage of the power supply recovers from a reduced state to a normal state.

[0066] The engine control section 63 corresponds to the "judging section" of the present application.

[0067] The ESB-ECU 55 is constituted by a microcomputer having a CPU, a ROM, a RAM, and the like. The microcomputer reads and executes programs and data stored in the ROM to work in a manner of performing control of execution of various functions including the brake force control function possessed by the ESB-ECU 55.

[0068] The ESB-ECU 55 has a function of generating a brake hydraulic pressure (secondary hydraulic pressure) by operating an electric cylinder device (for example, refer to Japanese Patent Application Publication No. 2015-110378 (JP 2015-110378 A): not illustrated) by driving of the brake motor 43 in accordance with the brake hydraulic pressure generated by a master cylinder (not illustrated).

[0069] The VSA-ECU57 consists of a microcomputer with a CPU, ROM, RAM, etc. This microcomputer reads and executes the programs and data stored in the ROM to perform various functions, including the braking control function based on ACC and the vehicle attitude stabilization function of the VSA-ECU57.

[0070] For example, the VSA-ECU57 receives a deceleration control command from the HDC-ECU51 and uses the pump motor 45 to drive the pressure pump (not shown), thereby controlling the braking force of the four wheels to match the target hydraulic pressure of each wheel.

[0071] In summary, when a deceleration control requirement related to HDC is generated, VSA-ECU57 works in conjunction with HDC-ECU51 to perform deceleration control based on a pre-set target vehicle speed VStg, regardless of the braking operation performed by the driver of the vehicle.

[0072] VSA-ECU57 and HDC-ECU51 together constitute the "Hill Descent Control Unit" of the present invention. VSA-ECU57 performs the function of "performing deceleration control based on target vehicle speed VStg" among the functions of the "Hill Descent Control Unit" of the present invention.

[0073] [Operation of the vehicle control device 11 according to an embodiment of the present invention]

[0074] Next, refer to Figure 2 The operation of the vehicle control device 11 according to an embodiment of the present invention will be explained. Figure 2 This is a flowchart illustrating the operation of the vehicle control device 11 used in an embodiment of the present invention.

[0075] As a premise, Figure 2 In step S11 shown, for the vehicle control device 11 of this embodiment, engine restart requirements related to IS control and deceleration control requirements related to HDC control are generated concurrently in time. Furthermore, it is assumed that the vehicle is on a downhill road. It is assumed that the automatic transmission (not shown) is set to a forward gear.

[0076] exist Figure 2 In step S11 shown, the engine control unit 63 of ENG-ECU53 starts the restart control of engine 41 according to the engine restart request related to IS control. Then, the power supply voltage VTG of the vehicle battery is supplied to the starter motor (not shown), thereby rotating the crankshaft (not shown) of engine 41.

[0077] Furthermore, at the point in step S11, the deceleration control requirements related to HDC control are retained.

[0078] In step S12, the vehicle control device 11 initially sets the cumulative value CNT of the timer (not shown) to (0).

[0079] In step S13, the vehicle control device 11 increments the cumulative value CNT of the timer (CNT = CNT + 1).

[0080] In step S14, the engine control section 63 belonging to the ENG-ECU 53 performs a judgment as to whether the engine rotational speed NE acquired by the information acquisition section 61 exceeds the knock threshold value NEth corresponding to the knock state of the engine 41. Here, the knock state of the engine 41 means a state in which the engine 41 is driven autonomously without the assistance of the starter motor.

[0081] In the case where the judgment of the result of the judgment in step S14 is such that the engine rotational speed NE does not exceed the knock threshold value NEth (NO in step S14), the vehicle control device 11 advances the flow of the process to the next step S15. On the other hand, in the case where the judgment of the result of the judgment in step S14 is such that the engine rotational speed NE exceeds the knock threshold value NEth (YES in step S14), the vehicle control device 11 jumps the flow of the process to step S16.

[0082] In step S15, the vehicle control device 11 performs a judgment as to whether the cumulative value CNT of the timer exceeds the time threshold value CNTth, which is a threshold value corresponding to the knock time at which it is assumed that the engine 41 will shift to the knock state if it is normal.

[0083] In the case where the judgment of the result of the judgment in step S15 is such that the cumulative value CNT of the timer does not exceed the time threshold value CNTth (NO in step S15), the vehicle control device 11 returns the flow of the process to step S13 and sequentially performs the subsequent process.

[0084] On the other hand, in the case where the judgment of the result of the judgment in step S15 is such that the cumulative value CNT of the timer exceeds the time threshold value CNTth (YES in step S15), the vehicle control device 11 advances the flow of the process to the next step S16.

[0085] In step S16, the engine control section 63 belonging to the ENG-ECU 53 permits the execution of the HDC control.

[0086] In summary, in the vehicle control device 11 of the embodiment of the present application, the engine control section 63 cancels the reservation of the request for deceleration control related to the HDC control and allows execution of the HDC control in the case where the engine 41 shifts to the knock state or the time from the start of the engine restart control of the engine 41 has elapsed by a knock time set as a time at which the engine 41 would shift to the knock state if it were normal.

[0087] 〔Timing operation of the vehicle control device 11 of the embodiment of the present application〕

[0088] Next, the timing operation of the vehicle control device 11 of the embodiment of the present application will be described with reference to Figure 3A , Figure 3B

[0089] Figure 3A is a timing chart for explaining the operation of the vehicle control device 11 in the case where the engine 41 shifts to the knock state within a prescribed time from the start of the engine restart control. Figure 3B is a timing chart for explaining the operation of the vehicle control device 11 in the case where the engine 41 does not shift to the knock state within a prescribed time from the start of the engine restart control.

[0090] 〔Case where the engine 41 shifts to the knock state within a prescribed time〕

[0091] First, the timing operation of the vehicle control device 11 in the case where the engine 41 shifts to the knock state within a prescribed time from the start of the engine restart control will be described with reference to Figure 3A As a premise, it is assumed that the host vehicle is present on a downhill road. In addition, it is assumed that the shift position of the automatic transmission is set to the forward range.

[0092] At time tO to t1 immediately before, the brake operation state indicated by the presence or absence of the brake pedal depression operation is the on state (brake pedal depression operation). The engine restart state is the off state (no engine restart). The engine rotation speed NE is zero (engine 41 is stopped). The power supply voltage VTG of the vehicle-mounted storage battery is the light load potential. The cumulative value CNT of the timer is (0). The HDC control state is the standby state (execution of the HDC control is not allowed). The caliper pressure is the braking force in accordance with the brake operation. The vehicle speed VS of the host vehicle is zero (parking state).

[0093] At time t1, the brake operation state shifts from the on state to the off state (no brake pedal depression operation). Along with this, the engine restart state shifts from the off state (no engine restart) to the on state (engine restart). In summary, at time t1, the engine restart control is started.

[0094] ​At this time t1, the engine rotation speed NE is still zero (the engine 41 is stopped). The power supply voltage VTG of the vehicle-mounted storage battery is still the light load potential. The cumulative value CNT of the timer is still (0). The HDC control state is shifted from the standby state to the semi-activation state (allowing execution of a part of the HDC control: allowed because the brake hydraulic pressure maintenance and the brake hydraulic pressure reduction based on the pump motor 45 do not require large electric power. However, the brake hydraulic pressure increase based on the pump motor 45 requires large electric power, and is not allowed). The caliper pressure is sharply reduced from the brake force in accordance with the brake operation. The vehicle speed VS of the host vehicle is still zero (the stop state).

[0095] Immediately before the time t2, the brake operation state maintains the off state (no brake pedal depression operation). The engine restart state maintains the on state (with engine restart). The engine rotation speed NE is the rotation speed characteristic in accordance with the rotation force of the crankshaft based on the starter motor. The power supply voltage VTG of the vehicle-mounted storage battery is the heavy load potential of the characteristic due to the operation of the starter motor, which is lower than the light load potential. The cumulative value CNT of the timer is the value that is linearly increased according to the passage of time (however, CNT < CNTth). The HDC control state maintains the semi-activation state. The caliper pressure maintains the value sharply reduced from the brake force in accordance with the brake operation (the brake force due to the brake hydraulic pressure maintenance based on the pump motor 45). The vehicle speed VS of the host vehicle is the acceleration characteristic in accordance with the gradient angle of the downhill road.

[0096] At the time t2, the engine rotation speed NE exceeds the burst threshold value NEth corresponding to the burst state of the engine 41. Along with this, the engine restart state is shifted from the on state (with engine restart) to the off state (without engine restart). The HDC control state is shifted from the semi-activation state to the activation state (allowing execution of the HDC control: allowing the entire brake hydraulic pressure increase, maintenance, and reduction based on the pump motor 45).

[0097] At this time t2, the brake operation state maintains the off state (no brake pedal depression operation). The power supply voltage VTG of the vehicle-mounted storage battery is the voltage value near the voltage threshold value VTGth, which is an index of the heavy load stable electric power supply with respect to the starter motor, the pump motor 45, and the like. The cumulative value CNT of the timer is the value that is linearly increased according to the passage of time (however, CNT < CNTth). The caliper pressure still maintains the value sharply reduced from the brake force in accordance with the brake operation. The vehicle speed VS of the host vehicle is the value slightly exceeding the target vehicle speed VStg.

[0098] After time t2, the brake operation state remains in the off state (no brake pedal depression operation). The engine restart state remains in the off state (no engine restart). The engine rotation speed NE assumes a speed value (NE > NEth) in accordance with the accelerator pedal-based acceleration operation. The power supply voltage VTG of the on-vehicle storage battery assumes a light load potential (VTG > VTGth). The cumulative value CNT of the timer assumes a value that increases linearly with the passage of time. The HDC control state remains in the active state. The caliper pressure that indicates the braking force assumes a value in accordance with the HDC control deceleration control. The vehicle speed VS of the host vehicle assumes a value that converges around the target vehicle speed VStg.

[0099] 〔Case where engine 41 does not shift to the explosion state within a prescribed time from the start point of engine restart control〕

[0100] Next, the time-series action of the vehicle control device 11 in the case where the engine 41 does not shift to the explosion state within a prescribed time from the start point of engine restart control will be described with reference to Figure 3B As a premise, it is assumed that the host vehicle exists on a downhill road. In addition, it is assumed that the shift position of the automatic transmission is set to the forward range.

[0101] At times tO to tll, the brake operation state is in the on state (brake pedal depression operation). The engine restart state is in the off state (no engine restart). The engine rotation speed NE is zero (engine 41 stopped). The power supply voltage VTG of the on-vehicle storage battery assumes a light load potential. The cumulative value CNT of the timer is (0). The HDC control state is in the standby state (HDC control execution not permitted). The caliper pressure assumes a braking force in accordance with the brake operation. The vehicle speed VS of the host vehicle is zero (parking state).

[0102] At time tl l, the brake operation state shifts from the on state to the off state (no brake pedal depression operation). In conjunction with this, the engine restart state shifts from the off state (no engine restart) to the on state (engine restart). In summary, at time tl l, the engine restart control is started.

[0103] At this time tl l, the engine rotation speed NE is still zero (engine 41 stopped). The power supply voltage VTG of the on-vehicle storage battery still assumes a light load potential. The cumulative value CNT of the timer is still (0). The HDC control state shifts from the standby state to the semi-active state. The caliper pressure sharply and abruptly decreases from the braking force in accordance with the brake operation. The vehicle speed VS of the host vehicle is still zero (parking state).

[0104] Immediately before time tl l ~ tl 2, the brake operation state is maintained in the closed state (no brake pedal depression operation). The engine restart state is maintained in the open state (engine restart is present). The engine rotation speed NE assumes a rotation speed characteristic in conformity with the rotation force of the crankshaft realized by the starter motor. The power supply voltage VTG of the vehicle-mounted storage battery assumes a heavy load potential characteristic caused by the operation of the starter motor, which is lower than the light load potential. The cumulative value CNT of the timer assumes a value that increases linearly with the passage of time (however, CNT < CNTth). The HDC control state is maintained in the semi-active state. The caliper pressure is maintained at a value that sharply decreases from the brake force in conformity with the brake operation. The vehicle speed VS of the host vehicle assumes an acceleration characteristic in conformity with the gradient angle of the downhill road.

[0105] At time tl 2, the cumulative value CNT of the timer exceeds the time threshold value CNTth (CNT > CNTth) corresponding to the knock time at which it is assumed that the engine 41 would shift to the knock state if the engine 41 were to normally operate.

[0106] Further, at this time tl 2, the power supply voltage VTG of the vehicle-mounted storage battery also just exceeds the index, i.e., the voltage threshold value VTGth, at which stable power supply with respect to the heavy load of the starter motor, the pump motor 45, etc. is possible.

[0107] However, at this time tl 2, the engine rotation speed NE does not reach the knock threshold value NEth corresponding to the knock state of the engine 41 for some reason such as abnormality of the starter motor.

[0108] In this case, execution of the HDC control is permitted at this time tl 2. That is, the HDC control state shifts from the semi-active state to the active state. In summary, in the case where the engine 41 does not shift to the knock state within the prescribed time from the start point (time tl l) related to the engine restart control, execution of the HDC control is permitted until the point (time tl 2) at which the cumulative value CNT of the timer exceeds the above-described time threshold value CNTth (CNT > CNTth).

[0109] At this time tl 2, the brake operation state is maintained in the closed state (no brake pedal depression operation). The engine restart state is maintained in the open state (engine restart is present). The HDC control state shifts from the semi-active state to the active state. The caliper pressure is still maintained at a value that sharply decreases from the brake force in conformity with the brake operation. Since execution of the deceleration control related to the HDC control is not performed, the vehicle speed VS of the host vehicle assumes a value that sharply exceeds the target vehicle speed VStg.

[0110] After time t12, the brake operation state maintains the off state (no brake pedal depression operation). The engine restart state maintains the on state (engine restart is present). The engine rotation speed NE assumes a rotation speed characteristic that corresponds to the rotation force of the crankshaft achieved by the starter motor (however, NE < NEth). The power supply voltage VTG of the vehicle-mounted battery maintains a voltage value in the vicinity of the voltage threshold VTGth. The cumulative value CNT of the timer assumes a value that increases linearly with the passage of time. The HDC control state maintains the active state. The caliper pressure assumes a value that corresponds to the deceleration control of the HDC control. The vehicle speed VS of the host vehicle assumes a characteristic that gradually converges on the vicinity of the target vehicle speed VStg.

[0111] 〔Action of the vehicle control device 11 of the modified example of the present application〕

[0112] Next, the action of the vehicle control device 11 of the modified example of the present application will be described with reference to Figure 4 Figure 4 is a flowchart for the action explanation of the vehicle control device 11 of the modified example of the present application.

[0113] As a premise, in Figure 4 the step S21 shown in FIG. 8, for the vehicle control device 11 of the modified example of the present application, the engine restart request related to the IS control and the deceleration control request related to the HDC control are generated in time overlap. In addition, it is assumed that the host vehicle is present on a downhill road. It is assumed that the shift position of the automatic transmission is set to the forward range.

[0114] In Figure 4 the step S21 shown in FIG. 8, the engine control section 63 belonging to the ENG-ECU 53 starts the restart control of the engine 41 in accordance with the engine restart request related to the IS control. Then, the power supply voltage VTG of the vehicle-mounted battery is supplied to the starter motor (not shown), whereby the crankshaft (not shown) of the engine 41 is rotated.

[0115] Further, at the point of time of the step S21, the deceleration control request related to the HDC control is retained.

[0116] In the step S22, the information acquisition section 61 belonging to the ENG-ECU 53 acquires the power supply voltage VTG of the vehicle-mounted battery in the state where the starter motor is connected to the terminal as a heavy load.

[0117] In the step S24, the engine control section 63 belonging to the ENG-ECU 53 performs the judgment as to whether the engine rotation speed NE acquired by the information acquisition section 61 exceeds the knock threshold NEth corresponding to the knock state of the engine 41.

[0118] ​In the case where the result of the determination in step S24 is a determination that the engine rotational speed NE does not exceed the kickback threshold NEth (NO in step S24), the modified vehicle control device 11 advances the flow of the process to the next step S25. On the other hand, in the case where the result of the determination in step S24 is a determination that the engine rotational speed NE exceeds the kickback threshold NEth (YES in step S24), the modified vehicle control device 11 jumps the flow of the process to step S26.

[0119] In step S25, the modified vehicle control device 11 performs a determination as to whether the power supply voltage VTG of the vehicle-mounted storage battery exceeds a criterion, i.e., a voltage threshold VTGth, for which stable power supply with respect to a heavy load such as the starter motor or the pump motor 45 is possible.

[0120] In the case where the result of the determination in step S25 is a determination that the power supply voltage VTG of the vehicle-mounted storage battery does not exceed the voltage threshold VTGth (NO in step S25), the modified vehicle control device 11 returns the flow of the process to step S22 and sequentially executes the following process.

[0121] On the other hand, in the case where the result of the determination in step S25 is a determination that the power supply voltage VTG of the vehicle-mounted storage battery exceeds the voltage threshold VTGth (YES in step S25), the modified vehicle control device 11 advances the flow of the process to the next step S26.

[0122] In step S26, the engine control section 63 belonging to the ENG-ECU 53 allows execution of the HDC control.

[0123] In summary, in the modified vehicle control device 11, the engine control section 63 cancels the reservation of the deceleration control request related to the HDC control and allows execution of the HDC control in the case where the engine 41 shifts to the kickback state or the power supply voltage VTG of the vehicle-mounted storage battery exceeds the criterion, i.e., the voltage threshold VTGth, for which stable power supply with respect to a heavy load such as the starter motor or the pump motor 45 is possible.

[0124] 〔Effects of the vehicle control device 11 of the embodiment of the present application〕

[0125] Next, the effects of the vehicle control device 11 of the embodiment of the present application will be described.

[0126] The vehicle control device 11 based on the first viewpoint has an engine control section 63 that performs idling stop control (IS control) that stops driving of an engine 41 that is a drive source of the host vehicle in accordance with satisfaction of a prescribed stop condition, and that performs engine restart control in accordance with satisfaction of a prescribed restart condition, a steep slope gentle descent control section (HDC-ECU 51, VSA-ECU 57) that performs deceleration control based on a target vehicle speed VStg that is set in advance in the case where the host vehicle is running on a downhill road and a deceleration control request related to steep slope gentle descent control (HDC control) is generated, regardless of a brake operation by a driver of the host vehicle, and an information acquisition section 61 that acquires information on a progress condition including start and end of the engine restart control.

[0127] And the following configuration is adopted: in the case where the engine restart request related to the IS control and the deceleration control request related to the HDC control are generated overlapping in time, the engine control section 63 prioritizes the engine restart control, and the steep slope gentle descent control section (HDC-ECU 51, VSA-ECU 57) allows execution of the deceleration control based on the target vehicle speed VStg based on the acquired progress condition including the start and end of the engine restart control.

[0128] As a premise, both the engine restart request related to the IS control and the deceleration control request related to the HDC control require relatively large electric power in order to respond to the request. Therefore, in the case where a power source mounted on the host vehicle is shared as a power source used when responding to the engine restart request related to the IS control and a power source used when responding to the deceleration control request related to the HDC control, and in the case where the engine restart request related to the IS control and the deceleration control request related to the HDC control are generated overlapping in time, there is a concern that the capacity of the power source will be insufficient to respond to both of the requests at the same time, resulting in discomfort for the occupant.

[0129] In view of this, in the vehicle control device 11 based on the first viewpoint, in the case where the engine restart request related to the IS control and the deceleration control request related to the HDC control are generated overlapping in time, the engine control section 63 prioritizes the engine restart control, whereby the engine restart request can be responded to promptly. Thus, smooth vehicle control that does not cause discomfort for the occupant can be achieved. Further, in the point of setting the host vehicle to a state in which the host vehicle can run, the engine restart control is performed prioritizing the HDC control based on the design idea that the matter on the downhill road should be prioritized compared to the speed control based on the target vehicle speed VStg, whereby the engine is set to an operating state.

[0130] On the other hand, the steep slope gentle descent control section allows execution of deceleration control based on the target vehicle speed VStg based on the acquired progress condition including the start and the end related to engine restart control, for example, until completion of the start and the end related to engine restart control, whereby it is possible to promptly respond to a deceleration control request related to HDC control after engine restart. Thus, it is possible to prevent an unexpected HDC control failure caused by a shortage of power supply capacity that can occur when IS control and HDC control are executed at the same time.

[0131] In addition, in the deceleration control based on the target vehicle speed VStg related to HDC control, it is possible to improve the degree of freedom in setting the target vehicle speed VStg. This is because, for the purpose of suppressing the situation in which HDC control is executed as much as possible at the time of conflict between IS control and HDC control, it is not necessary to take measures such as setting the target vehicle speed VStg high.

[0132] According to the vehicle control device 11 based on the first viewpoint, even in a scenario in which an engine restart request related to IS control and a deceleration control request related to HDC control occur overlapping in time, it is possible to achieve smooth vehicle control that does not cause discomfort to the occupant.

[0133] In addition, it is possible to prevent an unexpected HDC control failure caused by a shortage of power supply capacity that can occur when IS control and HDC control are executed at the same time.

[0134] In addition, in the deceleration control based on the target vehicle speed VStg related to HDC control, it is possible to improve the degree of freedom in setting the target vehicle speed VStg. As a result, it is possible to improve the marketability when traveling on a steep and steep downhill road.

[0135] Furthermore, since it is possible to suppress conflict of load power that the power supply should correspond to, it is also possible to expect a secondary effect of reducing the power supply capacity (pursuing power supply weight reduction).

[0136] In addition, the vehicle control device 11 based on the second viewpoint can also adopt the following configuration in the vehicle control device 11 based on the first viewpoint: the steep slope gentle descent control section allows execution of deceleration control based on the target vehicle speed VStg in a case where engine restart has not ended within a prescribed time from a start point of engine restart.

[0137] In the vehicle control device 11 based on the second viewpoint, the steep slope gentle descent control section allows execution of deceleration control based on the target vehicle speed VStg in a case where the engine restart has not ended within the prescribed time from the start point of the engine restart. Even in a case where the engine restart is not smoothly executed for some reason such as a starter motor malfunction, execution of deceleration control based on the target vehicle speed VStg is allowed upon elapse of the prescribed time from the start point of the engine restart.

[0138] According to the vehicle control device 11 based on the second viewpoint, on the basis of the effect of the vehicle control device 11 based on the first viewpoint, even in a case where the engine restart is not smoothly executed for some reason, execution of deceleration control based on the target vehicle speed VStg is timely and accurately performed upon elapse of the prescribed time from the start point of the engine restart.

[0139] In addition, the vehicle control device 11 based on the third viewpoint has an engine control section 63 that performs idle stop control (IS control) that stops driving of the engine 41 that is a drive source of the host vehicle in accordance with satisfaction of a prescribed stop condition, and that performs engine restart control in accordance with satisfaction of a prescribed restart condition, a steep slope gentle descent control section (HDC-ECU 51, VSA-ECU 57) that performs deceleration control based on a target vehicle speed VStg that is set in advance in a case where the host vehicle is traveling on a downhill road and a deceleration control request related to steep slope gentle descent control (HDC control) is generated, regardless of a brake operation by a driver of the host vehicle, and an information acquisition section 61 that acquires information on a progress condition including start and end of the engine restart control.

[0140] A power source used when the engine restart control is performed and a power source used when the deceleration control is performed share one power source mounted on the host vehicle.

[0141] The engine control section 63 (judgment section) that monitors a voltage variation of the one power source that occurs with the engine restart and judges whether the voltage of the one power source recovers from a reduced state to a normal state is further provided.

[0142] A configuration can also be adopted in which, in a case where an engine restart request related to the IS control and a deceleration control request related to the HDC control are generated overlapping in time, the engine control section 63 preferentially performs the engine restart control, and the steep slope gentle descent control section allows execution of deceleration control based on the target vehicle speed VStg in a case where the engine control section 63 (judgment section) makes a judgment that the voltage of the one power source recovers from the reduced state to the normal state.

[0143] In the vehicle control device 11 based on the third viewpoint, as with the vehicle control device 11 based on the first viewpoint, in a case where the engine restart request related to the IS control and the deceleration control request related to the HDC control are generated overlapping in time, the engine control section 63 prioritizes the engine restart control, whereby the engine restart request can be responded to promptly. Thus, smooth vehicle control that does not cause discomfort to the occupant can be achieved.

[0144] On the other hand, the steep slope gentle descent control section, in a case where the engine control section 63 (the determination section) makes a determination that the voltage of the one power source has returned to the normal state from the reduced state, allows execution of the deceleration control based on the target vehicle speed VStg, whereby the deceleration control request related to the HDC control can be responded to promptly until the voltage of the one power source returns to the normal state.

[0145] Thus, an unexpected HDC control failure caused by a shortage of power source capacity that can occur when the IS control and the HDC control are executed simultaneously can be prevented.

[0146] In addition, in the deceleration control related to the HDC control based on the target vehicle speed VStg, as with the vehicle control device 11 based on the first viewpoint, the degree of freedom of the setting of the target vehicle speed VStg can be increased. This is because, for the purpose of suppressing the situation where the HDC control is executed as much as possible at the time of the conflict between the IS control and the HDC control, there is no need to take measures such as setting the target vehicle speed VStg high.

[0147] According to the vehicle control device 11 based on the third viewpoint, as with the vehicle control device 11 based on the first viewpoint, even in a scenario where the engine restart request related to the IS control and the deceleration control request related to the HDC control are generated overlapping in time, smooth vehicle control that does not cause discomfort to the occupant can be achieved.

[0148] In addition, an unexpected HDC control failure caused by a shortage of power source capacity that can occur when the IS control and the HDC control are executed simultaneously can be prevented.

[0149] In addition, in the deceleration control related to the HDC control based on the target vehicle speed VStg, the degree of freedom of the setting of the target vehicle speed VStg can be increased. As a result, the marketability when running on a steep and steep downhill road can be improved.

[0150] Furthermore, since the conflict of the load power that the power source should cope with can be suppressed, a secondary effect of reducing the power source capacity (pursuing power source weight reduction) can also be expected.

[0151] The vehicle control device 11 based on the fourth aspect can further include the engine control section 63 (the determination section) determining whether or not the elapsed time from the start point related to the engine restart control exceeds a prescribed time. The steep slope gentle descent control section permits execution of the deceleration control based on the target vehicle speed VStg in a case where the determination is made by the engine control section 63 that the elapsed time from the start point related to the engine restart control exceeds the prescribed time.

[0152] In the vehicle control device 11 based on the fourth aspect, the steep slope gentle descent control section permits execution of the deceleration control based on the target vehicle speed VStg in a case where the determination is made by the engine control section 63 that the elapsed time from the start point related to the engine restart control exceeds the prescribed time. Here, as the prescribed time, a time length equivalent to the knock time, which is assumed to be a time when the engine 41 shifts to the knock state if it is normal, is set, for example.

[0153] In this case, the steep slope gentle descent control section permits execution of the deceleration control based on the target vehicle speed VStg after the elapsed time from the start point related to the engine restart control exceeds the knock time, which is assumed to be a time when the engine 41 shifts to the knock state if it is normal, in other words, until the engine 41 shifts to the knock state.

[0154] According to the vehicle control device 11 based on the fourth aspect, it is possible to permit execution of the deceleration control based on the target vehicle speed VStg until the engine 41 shifts to the knock state.

[0155] Further, since the reference of whether or not the engine 41 shifts to the knock state is made by the elapsed time from the start point related to the engine restart control, it is possible to perform the switching from the IS control to the HDC control simply and in a timely manner.

[0156] Further, the vehicle control device 11 based on the fifth aspect can be configured as the vehicle control device 11 based on the third aspect, in which the engine control section 63 (the determination section) monitors the voltage variation of the one power supply, and makes the determination that the voltage of the one power supply recovers from the reduced state to the normal state in a case where the voltage value of the one power supply increases from below the prescribed voltage threshold VTGth to exceed the voltage threshold VTGth.

[0157] In the vehicle control device 11 based on the fifth viewpoint, the engine control section 63 (determination section) makes a determination that the voltage of the one power supply has returned to the normal state in which stable power supply is possible even with respect to a heavy load, in the case where the voltage value of the one power supply increases from below the prescribed voltage threshold VTGth to above the voltage threshold VTGth. Here, as the prescribed voltage threshold VTGth, a threshold value is set at which stable power supply with respect to a heavy load such as the starter motor or the pump motor 45 is possible.

[0158] In this case, the engine control section 63 makes a determination that the voltage of the one power supply has returned to the normal state in which stable power supply is possible even with respect to a heavy load, in the case where the voltage value of the one power supply increases from below the prescribed voltage threshold VTGth to above the voltage threshold VTGth.

[0159] According to the vehicle control device 11 based on the fifth viewpoint, the timing at which the power supply capability of the one power supply returns can be accurately grasped, and thus the switching from IS control to HDC control can be performed in a timely and accurate manner.

[0160] 〔Other Embodiments〕

[0161] The various embodiments described above represent examples of the embodiment of the present application. Therefore, the technical scope of the present application cannot be limitatively interpreted by these examples. The present application can be implemented in various ways without departing from the gist thereof or the main features thereof.

[0162] For example, in the description of the vehicle control device 11 of the embodiment of the present application, the HDC-ECU 51 and the VSA-ECU 57 jointly constitute the "steep slope gradual descent control section" of the present application, but the present application is not limited to this example.

[0163] For example, the "steep slope gradual descent control section" of the present application can also be constituted by a consolidated ECU having the functions of the HDC-ECU 51 and the VSA-ECU 57.

[0164] As with the above, the "vehicle control device" of the present application can also be constituted by a consolidated ECU having the functions of the HDC-ECU 51 and the VSA-ECU 57, to which the function of the ENG-ECU 53 is additionally attached.

Claims

1. A vehicle control device, characterized in that, have: The engine control unit performs idle stop control to stop the drive of the engine, which is the drive source of the vehicle, based on the satisfaction of the prescribed stop conditions, and performs engine restart control based on the satisfaction of the prescribed restart conditions. The hill descent control unit, when the vehicle is traveling downhill and a deceleration control requirement related to hill descent control is generated, performs deceleration control based on a pre-set target speed regardless of the braking operation performed by the driver. and The information acquisition unit acquires information on the progress status, including the start and completion of processes related to engine restart control. When engine restart requirements related to idle stop control and deceleration control requirements related to hill descent control overlap in time, the engine control unit prioritizes engine restart control, and the hill descent control unit... If the engine restart has not ended by the point in time from the start of the engine restart based on the process status, and a predetermined time defined by the burst time has elapsed, the execution of deceleration control based on the target vehicle speed is permitted, where the burst time is the time at which the engine is assumed to transition to the burst state.

2. A vehicle control device, characterized in that, have: The engine control unit performs idle stop control to stop the drive of the engine, which is the drive source of the vehicle, based on the satisfaction of the prescribed stop conditions, and performs engine restart control based on the satisfaction of the prescribed restart conditions. The hill descent control unit, when the vehicle is traveling downhill and a deceleration control requirement related to hill descent control is generated, performs deceleration control based on a pre-set target speed regardless of the braking operation performed by the driver. and The information acquisition unit acquires information on the process status, including the start and end of processes related to engine restart control. The power supply used for executing the engine restart control and the power supply used for executing the deceleration control share a single power source in this vehicle. It also has a judgment unit that monitors the voltage fluctuation of the power supply that occurs during engine restart and determines whether the voltage of the power supply has recovered from a reduced state to a normal state. When engine restart requirements related to idle stop control and deceleration control requirements related to hill descent control overlap in time, the engine control unit prioritizes engine restart control, and the hill descent control unit allows the execution of deceleration control based on the target vehicle speed when the determination unit determines that the voltage of one power source has returned to normal from a reduced state. The determination unit further determines whether the elapsed time from the start point related to engine restart control based on the process status exceeds a predetermined time defined by the burst time, which is the time it is assumed that the engine will transition to a burst state. If the determination unit determines that the elapsed time since the start point related to engine restart control has exceeded the predetermined time, and if the determination unit does not determine that the voltage of the power supply has recovered from the reduced state to the normal state at the time the determination is made, the hill descent control unit allows the execution of deceleration control based on the target vehicle speed.

3. The vehicle control device according to claim 2, characterized in that, The judgment unit monitors the voltage fluctuation of the power supply, and when the voltage value of the power supply increases from below a predetermined voltage threshold to exceed the voltage threshold, it makes a judgment that the voltage of the power supply has returned to a normal state from a reduced state.

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