JP2017001585A - Vehicle control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control apparatus capable of suppressing variation in a start responsiveness of a vehicle having an idling-stop function in the case of retaining brake force exerted to the vehicle even after starting an engine initiated by a brake release operation.SOLUTION: An apparatus includes: an engine control part for stopping an engine automatically in the case of meeting a given stoppage condition and starting the engine automatically in the case of meeting a given start condition including a brake release operation; a first ignition cylinder obtainment part for obtaining as to which of plural cylinders is a first ignition cylinder that is initially ignited when the engine starts automatically; a crank angle obtainment part for obtaining a crank angle CA at the first ignition cylinder when the engine stops automatically; and a brake control part for retaining given brake force exerted to the vehicle after a brake release operation included in the start condition is performed. Further, the aforementioned brake force is differentiated in accordance with the crank angle.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vehicle control device for holding a braking force acting on a vehicle after the start of engine restart by a brake release operation in a vehicle having an idle stop function.

  Conventionally, a vehicle having a so-called idle stop function that automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when the predetermined start condition is satisfied after the stop condition is satisfied It has been known.

  In such a vehicle, in order to prevent jumping out at the time of engine start and slipping down on an uphill road, a technique for holding a braking force that acts on the vehicle even after the start of engine start by a brake release operation is known (for example, a patent Reference 1).

JP 2013-071472 A

  However, since the engine output at the start varies due to various factors, if the mode of the braking force to be held after the start of the engine is uniformly determined, the start response of the vehicle varies. Therefore, each time the engine is stopped and started repeatedly by the idle stop function, a situation in which the start response of the vehicle is different may occur, which may give the driver a sense of discomfort.

  Therefore, in view of the above problems, in a vehicle having an idle stop function, a vehicle capable of suppressing variations in start response when holding braking force acting on the vehicle even after the start of engine start by a brake release operation is held. An object is to provide a control device.

In order to achieve the above object, in one embodiment, a vehicle control device includes:
An engine having a plurality of cylinders as a driving force source of the vehicle;
Engine control that automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when a predetermined start condition including a brake release operation is satisfied after the stop condition is satisfied And
A first ignition cylinder acquisition unit that acquires which of the plurality of cylinders is a first ignition cylinder that is initially ignited when the engine is automatically started;
A crank angle obtaining unit for obtaining a crank angle in the first ignition cylinder when the engine is automatically stopped;
A brake control unit that holds a predetermined braking force acting on the vehicle after the brake release operation included in the start condition is performed while the vehicle is stopped;
The brake control unit
The braking force is varied according to the crank angle.

  According to the present embodiment, in a vehicle having an idle stop function, it is possible to suppress variations in start response when the braking force acting on the vehicle is retained even after the start of engine start by a brake release operation. A vehicle control device can be provided.

It is a block diagram which shows an example of a structure of a vehicle control apparatus. It is a schematic block diagram which shows an example of a structure of the brake system containing a brake actuator. It is a figure which shows an example of the detection aspect of the crank angle by a crank angle sensor. It is a figure which shows an example of a crank angle signal. It is a timing chart which shows an example of brake maintenance control and brake maintenance release control by a vehicle control device (idle stop ECU) concerning this embodiment. It is a flowchart which shows notionally an example of the brake holding | maintenance cancellation | release control by the vehicle control apparatus (idle stop ECU) which concerns on this embodiment. The figure which shows an example of the map which prescribes | regulates the braking force (wheel cylinder pressure) hold | maintained by brake holding | maintenance release control. It is a figure which shows the range (stop position range) of the crank angle of the 1st ignition cylinder at the time of an engine stop.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of the configuration of the vehicle control device 1 according to the present embodiment.

  In the figure, the double line represents the power transmission system, the solid line represents the power transmission system, and the dotted line represents the signal transmission system.

  The vehicle control device 1 is mounted on a vehicle and executes vehicle control (idle stop control) related to a so-called idle stop function. In addition, the vehicle control device 1 executes vehicle control (brake holding control) that automatically holds the braking force for maintaining the stop during the stop from the engine stop to the start by the idle top function. Further, the vehicle control device 1 maintains vehicle braking force that acts on the vehicle and gradually reduces the braking force (brake holding release control) even after the start of the engine by the idle stop function based on the brake releasing operation. ). Details will be described later.

  The idle stop function in the present embodiment includes a stop idle stop function that stops the engine 10 on condition that the vehicle is stopped, and a deceleration that can stop the engine 10 in a deceleration state before the vehicle stops. Includes both idle stop functions.

  As shown in FIG. 1, the vehicle control device 1 includes an engine 10, a starter 11, a starter relay 12, a battery 13, an engine ECU (Electronic Control Unit) 20, an idle stop ECU 30, a brake ECU 40, a brake actuator 50, a vehicle speed sensor 60, A negative pressure sensor 70, an MC pressure sensor 80, a crank angle sensor 90, and the like are included.

  The engine 10 is an internal combustion engine (for example, a gasoline engine or a diesel engine) as a driving force source of the vehicle. The engine 10 has a plurality of cylinders (for example, in-line 4 cylinders, V-type 6 cylinders, etc.), and 4 pistons of intake → compression → expansion by ignition → exhaust while pistons inserted in each cylinder reciprocate twice. A process is performed to produce a rotational movement of a crankshaft (not shown).

  The starter 11 is an engine starting means for starting the crankshaft of the engine 10 by rotational driving (cranking). The starter 11 is operated by the power of the battery 13 via the starter relay 12.

  The starter relay 12 is provided in a power supply path from the battery 13 to the starter 11. The starter relay 12 is normally opened (OFF) and is closed (ON) in response to a command from the engine ECU 20.

  The battery 13 is a power storage device that supplies electric power to an auxiliary machine mounted on a vehicle including the starter 11. The battery 13 may be a lead storage battery having a rated voltage of 12V, for example. The battery 13 can charge the generated power of an alternator (not shown) that can generate power using the power from the engine 10.

  The engine ECU 20 is an electronic control unit that controls the operating state of the engine 10. The engine ECU 20 may be constituted by, for example, a microcomputer and the like, and various control processes shown below can be realized by executing various programs stored in the ROM on the CPU.

  The engine ECU 20 closes the starter relay 12 and starts the engine 10 in response to an IG signal (ON signal) input in response to an ignition-on (IG-ON) operation. Further, the engine 10 is stopped by stopping the fuel supply to the engine 10 at a predetermined timing in accordance with an IG signal (OFF signal) input corresponding to the ignition-off (IG-OFF) operation.

  Further, the engine ECU 20 stops and starts the engine 10 by an idle stop function. Specifically, the engine 10 is stopped in response to the engine stop request received from the idle stop ECU 30, and the engine 10 is started in response to the start request received from the idle stop ECU 30.

  Further, the engine ECU 20 executes engine stop position control when stopping the engine 10 in response to the engine stop request received from the idle stop ECU 30. In the engine stop position control, in order to improve the startability of the engine 10, when the engine 10 is stopped by the idle stop function, the engine 10 is stopped in a crank angle range suitable for the next start. Specifically, at the time of the next start, the throttle opening is set so that the cylinder that is ignited first (first ignition cylinder) stops at a target stop crank angle that is set within a crank angle range suitable for the start. The rotational load estimated from the compression torque due to the in-cylinder pressure of each cylinder is controlled.

  The engine ECU 20 can receive a detection signal from a cylinder pressure sensor (not shown) provided in each cylinder.

  The idle stop ECU 30 is an electronic control unit that executes main control processing in the vehicle control apparatus 1 according to the present embodiment. The idle stop ECU 30 may be constituted by, for example, a microcomputer and the like, and various control processes shown below can be realized by executing various programs stored in the ROM on the CPU.

  The idle stop ECU 30 executes control processing (idle stop control) related to the idle stop function. Specifically, when a predetermined engine stop condition (all conditions included) is satisfied, an engine stop request is output to the engine ECU 20 to stop the engine 10. Further, after satisfying the stop condition, when a predetermined engine start condition (at least one of the conditions included therein) is satisfied, a start request is output to the engine ECU 20 to start the engine 10.

  Here, the engine stop condition includes, for example, a predetermined brake operation (depressing the brake pedal more than a predetermined value), a vehicle speed V being a predetermined speed Vth (≧ 0) or less, and the like. Further, the engine stop condition is generated by rotational driving of the engine 10 and negative pressure (for example, negative pressure generated in the intake manifold of the engine 10) supplied to the brake booster 46 (see FIG. 2) is a predetermined value or more. It may include that the state of charge of the battery 13 is good.

  Further, the engine start condition includes, for example, that a brake release operation is performed (a brake pedal depression operation has become a predetermined value or less). Further, the engine start condition may include that the negative pressure supplied to the brake booster 46 has become lower than a predetermined value, that the state of charge of the battery 13 has deteriorated to a predetermined value or higher.

  The idle stop ECU 30 can receive a detection signal corresponding to the brake hydraulic pressure (MC pressure) generated in the master cylinder 47 (see FIG. 2) in response to the driver's brake operation from the MC pressure sensor 80. In addition, a vehicle speed signal corresponding to the vehicle speed V can be received from the vehicle speed sensor 60. In the case of the stop idling stop function, the predetermined speed Vth = 0, and in the case of the deceleration idle stop function, the predetermined speed Vth> 0 (for example, 10 km / h).

  Further, the idle stop ECU 30 is a control for maintaining the stop of the vehicle while the engine 10 is stopped by the idle stop function (from the output of the engine stop request to the output of the start request) and while the vehicle is stopped. Holds power (brake holding control). Specifically, after satisfying the engine stop condition (after outputting the engine stop request) and satisfying both conditions that the vehicle is stopped, a brake holding request is output to the brake ECU 40.

  The idle stop ECU 30 continues to hold the braking force acting on the vehicle when the engine start condition is satisfied by releasing the brake operation after the engine stop condition is satisfied (after the engine stop request is output) and the vehicle is stopped. At the same time, the braking force is gradually reduced (brake holding release control). Specifically, when the engine start condition is satisfied by releasing the brake operation during the brake holding control, a brake holding release request is output to the brake ECU 40.

  The brake ECU 40 is an electronic control unit that controls the operating state of a vehicle brake system (for example, a hydraulic brake system). Specifically, a desired braking force is generated on the vehicle by outputting a control command to the brake actuator 50.

  The brake actuator 50 is output generating means for generating an output for operating a vehicle brake system (hydraulic brake system). Hereinafter, a vehicle brake system including the brake actuator 50 will be described with reference to FIG.

  FIG. 2 is a schematic configuration diagram illustrating an example of a configuration of a vehicle brake system (hydraulic brake system) including the brake actuator 50.

  The brake system includes a brake booster 46, a master cylinder 47, a brake actuator 50, and the like.

  The brake booster 46 amplifies the driver's operating force (brake pedaling force) by the brake pedal 45 using, for example, negative pressure supplied by a negative pressure pipe 48 connected to the intake manifold of the engine 10. The brake booster 46 is provided with a negative pressure sensor 70 that detects the negative pressure.

  The master cylinder 47 takes out the brake operation force amplified by the brake booster 46 as a brake hydraulic pressure (master cylinder pressure (MC pressure)). The master cylinder 47 is connected to the brake actuator 50 in two systems, and the generated MC pressure is introduced into the brake actuator 50.

  The brake actuator 50 includes a front wheel hydraulic system that supplies brake oil pressure (wheel cylinder pressure) to the two front wheel wheel cylinders 49 and a brake oil pressure (wheel cylinder pressure) of the two rear wheel wheel cylinders 49. It has a rear wheel hydraulic system to supply. Since the rear wheel hydraulic system has the same configuration as the front wheel hydraulic system, it is omitted in the figure. Hereinafter, the front wheel hydraulic system will be described.

  The front wheel hydraulic system includes a master cut valve 51, a holding valve 52, a pressure reducing valve 53, a reservoir 54, a hydraulic pump 55, a motor 56, an accumulator 57, and the like.

  The MC pressure introduced from the master cylinder 47 is normally output to the wheel cylinder 49 of each wheel through the normally open master cut valve 51 and the holding valve 52. As a result, the brake system can apply a braking force according to the driver's braking operation to the vehicle.

  Further, by closing the normally open master cut valve 51, the brake hydraulic pressure downstream of the master cut valve 51 can be maintained at the MC pressure immediately before closing. In other words, the brake system can perform the operation corresponding to the above-described brake holding control regardless of the brake operation by performing the operation of the brake actuator 50 according to the control command from the brake ECU 40.

  Further, by opening the normally closed pressure reducing valve from the operation state corresponding to the brake holding, the hydraulic oil is returned to the reservoir 54 and the held brake hydraulic pressure is reduced. That is, when the brake actuator 50 performs such an operation in response to a control command from the brake ECU 40, an operation corresponding to the brake holding release control described above can be performed.

  In the state where the master cut valve 51 is closed, the hydraulic pump 55 is driven by the motor 56 to accumulate pressure in the accumulator 57, thereby generating a brake hydraulic pressure higher than the MC pressure corresponding to the brake operation, and the wheel cylinder 58. Can also be output.

  Returning to FIG. 1, the vehicle speed sensor 60 is a known detection means for detecting the vehicle speed. The vehicle speed sensor 60 transmits a detection signal (vehicle speed signal) corresponding to the vehicle speed to the idle stop ECU 30 via an in-vehicle LAN or the like.

  The negative pressure sensor 70 is a known detection unit that detects the negative pressure supplied to the brake booster 46. The negative pressure sensor 70 transmits a detection signal (negative pressure signal) corresponding to the detected negative pressure to the idle stop ECU 30 via a one-to-one communication line (direct line), an in-vehicle LAN, or the like.

  The MC pressure sensor 80 is a known detection means for detecting the MC pressure. The MC pressure sensor 80 transmits a detection signal (MC pressure signal) corresponding to the detected MC pressure to the idle stop ECU 30 via a direct line, an in-vehicle LAN, or the like.

  The crank angle sensor 90 is a known detection unit that detects the crank angle of the engine 10. The crank angle sensor 90 is, for example, an MRE (Magneto Resistance Effect) sensor. Since the MRE sensor includes an MRE element whose electric resistance changes according to a change in the magnetic field, a pulse signal corresponding to the change in the magnetic field can be output. As shown in FIG. 3 (a diagram showing an example of a crank angle detection mode by the crank angle sensor), the crank angle sensor 90 is provided to face the outer peripheral portion of the rotor 92 that rotates integrally with the crankshaft. The crank angle sensor 90 detects a change in the magnetic field due to the teeth 92 a provided at equal intervals on the outer peripheral portion of the rotating metal rotor 92. Then, a pulse signal (crank angle signal) corresponding to the change in the magnetic field is generated and output.

  Here, as shown in FIG. 4 (a diagram showing an example of the crank angle signal), the crank angle signal is a pulse signal that repeats a narrow rectangular pulse corresponding to the teeth 92a provided at equal intervals on the outer periphery of the rotor 92. It is. Further, as shown in FIG. 3, there is a portion (missing tooth portion 92 b) in which the teeth 92 a are not provided in part in the circumferential direction of the rotor 92. Therefore, a wide rectangular pulse corresponding to the missing tooth portion 92b detected every rotation is sandwiched between repetitions of the narrow rectangular pulse corresponding to the tooth 92a. Accordingly, the crank angle can be detected by counting the narrow rectangular pulses corresponding to the teeth 92a on the basis of the wide pulses corresponding to the missing teeth 92b.

  The crank angle sensor 90 transmits a crank angle signal to the idle stop ECU 30 via an in-vehicle LAN or the like.

  Next, the brake holding control and the brake holding release control will be described in detail with reference to FIG.

  FIG. 5 is a timing chart showing an example of brake holding control and brake holding release control by the vehicle control device 1 (idle stop ECU 30) according to the present embodiment. Specifically, the brake oil pressure (MC pressure L1) from when the engine 10 is stopped after the engine stop condition is satisfied until the start of the engine 10 is started after the engine start condition is satisfied. , Represents a change in the wheel cylinder pressure L2).

  Referring to FIG. 5, first, at time t <b> 0, the engine 10 is stopped by the stop idle stop function, or after the engine 10 is stopped by the deceleration idle stop function, the vehicle is stopped. At this time (time t0), the idle stop ECU 30 outputs a brake holding request to the brake ECU 40, and the brake ECU 40 starts brake holding control in response to the brake holding request.

  From time t0 when the engine 10 is stopped to time t1, the MC pressure L1 corresponding to the brake operation force by the driver decreases with time. On the other hand, the wheel cylinder pressure L2 is held corresponding to the MC pressure at time t0 by closing the master cut valve 51 as described above by brake holding control. Thereby, the stop state of a vehicle can be maintained reliably.

  From time t1 when the stop of the engine 10 continues to time t2, the MC pressure L1 rises once. In the middle, it becomes larger than the time t0. At this time, when the brake ECU 40 determines that the maximum value (MC pressure at time t0) has been updated by monitoring the MC pressure signal from the MC pressure sensor 80, the brake ECU 40 opens the master cut valve 51. That is, in the brake holding control in the present embodiment shown in FIG. 5, when the MC pressure updates the past maximum value, the wheel cylinder pressure is caused to follow the increase in the MC pressure. Thereby, since the wheel cylinder pressure increases following the MC pressure, it is possible to more reliably maintain the vehicle stopped.

  From time t2 when the engine 10 continues to stop to time t3, the MC pressure L1 drops rapidly due to the release of the brake operation by the driver, and becomes zero at time t3. At this time, the brake ECU 40 holds the wheel cylinder pressure L2 at the MC pressure L1 at time t2 by closing the master cut valve 51 again at time t2.

  Since the engine start condition is satisfied at time t3 by releasing the brake operation of the driver, the idle stop ECU 30 outputs an engine start request to the engine ECU 20 and outputs a brake hold release request to the brake ECU 40.

  Between time t3 and time t4 when the engine 10 is starting, the brake ECU 40 adjusts the pressure reducing valve 53 as appropriate, thereby reducing the wheel cylinder pressure L2 at time t4 to a predetermined first pressure BP1. The time until the decompression is completed is set to a time shorter than the time required to complete the start of the engine 10 (time t4).

  When the start of the engine 10 is completed at the time t4, the brake ECU 40 changes the wheel cylinder pressure L2 from the predetermined first pressure BP1 at the time t4 to the time t5 during a predetermined pressure reduction time T1 (time t4 to t5). The pressure is reduced to a predetermined second pressure BP2.

  Subsequently, during the pressure reduction time T2 from time t5 (time t5 to t6), the wheel cylinder pressure L2 is reduced from the second pressure BP2 to 0, and the brake holding release control is ended.

  The engine ECU 20 determines that the engine 10 has been started based on detection signals from various sensors including the crank angle sensor 90, and outputs it to the in-vehicle LAN. Thereby, brake ECU40 can recognize the completion of starting of the engine 10 via vehicle-mounted LAN.

  As described above, even after the engine start condition is satisfied by the brake release operation and the engine 10 is started (after the engine start request is output), the idle stop ECU 30 is connected to the vehicle via the brake ECU 40. Brake holding release control for holding a predetermined braking force to be applied is executed. As a result, the vehicle slips on the slope between time t3 when the brake operation is released and time t4 when the engine 10 is started, or creep force generated after the start of the engine 10 (after time t4). It is possible to prevent the vehicle from jumping out.

  Next, a characteristic operation by the vehicle control device 1 according to the present embodiment, that is, a processing flow of brake holding release control will be described with reference to FIG.

  FIG. 6 is a flowchart conceptually showing an example of brake holding release control by the vehicle control device 1 (idle stop ECU 30) according to the present embodiment.

  This flowchart is executed after the engine 10 is stopped by the idle stop function (after the engine stop request is output) and when the vehicle is stopped.

  In step S101, the idle stop ECU 30 acquires the first ignition cylinder at the next start from the internal memory or the like. As described above, the idle stop ECU 30 determines the first ignition cylinder and then executes the engine stop position control. Therefore, the first ignition cylinder determined by the engine stop position control can be acquired from the internal memory or the like.

  In step S102, the idle stop ECU 30 acquires the crank angle CA of the first ignition cylinder when the engine 10 is stopped based on the crank angle signal received from the crank angle sensor 90.

  The crank angle CA of the first ignition cylinder is a crank angle defined locally with respect to the first ignition cylinder. For example, the crank angle CA of the first ignition cylinder is a crank angle (CA ATDC: Crank Angle After Top Center) after TDC (Top Dead Center) of the first ignition cylinder. Hereinafter, the crank angle detected by the crank angle sensor 90 is referred to as “absolute crank angle”, and is distinguished from the crank angle CA in the first ignition cylinder. However, since the absolute crank angle and the crank angle CA are associated with each other on a one-to-one basis, it is also possible to acquire which one of the first ignition cylinders is based on the absolute crank angle in step S101.

  Steps S103 to S107 are processes for setting the braking force held by the brake hold release control. Specifically, according to the crank angle CA of the first ignition cylinder from maps # 1 to # 3 (see FIG. 8) set in advance so that the braking force (wheel cylinder pressure) to be held is different. Make a map selection.

  In step S103, the idle stop ECU 30 determines whether or not the crank angle CA is not less than the predetermined angle AG1 and not more than the predetermined angle AG2 (> AG1) (AG1 ≦ CA ≦ AG2). The idle stop ECU 30 proceeds to step S105 if the condition is satisfied, and proceeds to step S104 if the condition is not satisfied.

  In step S104, the idle stop ECU 30 determines whether or not the crank angle CA is larger than the predetermined angle AG2 and equal to or smaller than the predetermined angle AG3 (> AG2) (AG2 <CA ≦ AG3). If the determination condition is satisfied, the idle stop ECU 30 proceeds to step S106, and if the determination condition is not satisfied (that is, the crank angle CA is larger than the predetermined angle AG3 and is equal to or less than a predetermined angle AG4 described later (AG3 <CA ≦ AG4)). ), The process proceeds to step S107.

  In step S105, the idle stop ECU 30 selects the map # 1 having the largest brake force (wheel cylinder pressure) to be held among the maps # 1 to # 3.

  In step S106, the idle stop ECU 30 selects the map # 2 having the second largest braking force (wheel cylinder pressure) among the maps # 1 and # 2.

  In step S107, the idle stop ECU 30 selects a map # 3 having the smallest braking force (wheel cylinder pressure) to be held.

  Here, FIG. 7 is a diagram showing an example of a map that defines the braking force (wheel cylinder pressure) held by the brake holding release control.

  Maps # 1 to # 3 shown in FIG. 7 indicate the master cylinder pressure during the period from the completion of the start of the engine 10 described in FIG. 5 until the master cylinder pressure is reduced (from time t4 to time t6 in FIG. 5). It defines how to reduce the amount.

  As described with reference to FIG. 5, the maps # 1 to # 3 linearly increase the wheel cylinder pressure from the predetermined first pressure BP1 to the predetermined second pressure BP2 during the pressure reduction time T1 after the start of the engine 10 is completed. The pressure is reduced, and the wheel cylinder pressure is linearly reduced from a predetermined second pressure BP2 to 0 during the subsequent pressure reduction time T2. The decompression times T1 and T2 are set to the same value in any of the maps # 1 to # 3. On the other hand, the first pressure BP1 and the second pressure BP2 are set to different values in the maps # 1 to # 3.

  In the map # 1, a predetermined pressure BP11 is set as the first pressure BP1, and a predetermined pressure BP21 is set as the second pressure BP2.

  In the map # 2, a predetermined pressure BP12 (<BP11) is set as the first pressure BP1, and a predetermined pressure BP22 (<BP21) is set as the second pressure BP2.

  In the map # 3, a predetermined pressure BP13 (<BP12) is set as the first pressure BP1, and a predetermined pressure BP23 (<BP22) is set as the second pressure BP2.

  That is, the wheel cylinder pressure (braking force acting on the vehicle) held by the brake holding release control is set to increase in the order of map # 3 → map # 2 → map # 1.

  Returning to FIG. 6, in step S <b> 108, the idle stop ECU 30 determines whether or not the engine 10 has been started (that is, whether or not an engine start request is output by itself). The idle stop ECU 30 proceeds to step S109 when the engine 10 is started, and repeats the process of this step until the engine 10 is started when the engine 10 is not started.

  In step S109, the idle stop ECU 30 determines whether the start of the engine 10 is due to a brake release operation. If the engine 10 is started by a brake release operation, the process proceeds to step S110. If not, the current process is terminated.

  In step S110, the idle stop ECU 30 performs brake holding release control along the map selected in any of steps S105 to 107 out of maps # 1 to # 3. That is, the idle stop ECU 30 transmits a brake holding release request including information regarding the selected map to the brake ECU 40. As a result, the brake ECU 40 keeps the braking force (wheel cylinder pressure) corresponding to the selected map based on the information of the maps # 1 to # 3 stored in advance in the internal memory or the like, and according to the passage of time. Reduce braking force (decrease wheel cylinder pressure).

  Next, the operation of the vehicle control device 1 according to the present embodiment will be described with reference to FIG.

  FIG. 8 is a diagram showing a range of the crank angle CA of the first ignition cylinder when the engine 10 is stopped.

  As shown in FIG. 8, the crank angle CA suitable for starting is, for example, between a predetermined angle AG1 and a predetermined angle AG4 with reference to TDC. That is, by the engine stop position control described above, the engine 10 is normally stopped so that the crank angle CA of the first ignition cylinder when the engine 10 is stopped is in a range between the predetermined angle AG1 and the predetermined angle AG4.

  However, although it is suitable for starting, there is a difference (variation) in the output generated when starting the engine 10 between the case where the crank angle CA is closer to the predetermined angle AG1 and the case where the crank angle CA is closer to the predetermined angle AG4. Arise. That is, the closer the crank angle CA is to the predetermined angle AG1, the higher the output generated when the engine 10 is started. The closer the crank angle CA is to the predetermined angle AG4, the more output is generated when the engine 10 is started. It tends to be lower. Therefore, in the case where the braking force held by the brake holding release control is uniformly set, the output at the start of the engine 10 may vary depending on the crank angle CA when the engine 10 is stopped. . That is, every time the engine 10 is repeatedly stopped and started by the idle stop function, the start response of the vehicle at the time of starting the engine 10 may vary. As a result, the driver may feel uncomfortable.

  Therefore, a configuration is adopted in which the braking force held by the brake hold release control is changed according to the crank angle CA of the first ignition cylinder when the engine 10 is stopped. Specifically, within the range from the predetermined angle AG1 to the predetermined angle AG4, as the crank angle CA approaches the predetermined angle AG1 (as the crank angle CA with respect to TDC becomes smaller), the brake holding release control holds it. Set a large braking force. More specifically, as described above, between the predetermined angle AG1 and the predetermined angle AG2 (first range), between the predetermined angle AG2 and the predetermined angle AG3 (second range), and between the predetermined angle AG3 and the predetermined angle AG4 ( Three ranges are set. Then, the braking force (wheel cylinder pressure) held by the brake holding release control is increased in the order of the third range → the second range → the first range. As a result, as the output of the engine 10 at the time of starting increases, the braking force to be held by the brake hold release control increases, so even if the engine output varies due to the influence of the crank angle CA, the vehicle start response varies. It becomes difficult to occur. That is, it is possible to suppress variations in the vehicle start response when the engine 10 is started.

  As mentioned above, although the form for implementing this invention was explained in full detail, this invention is not limited to this specific embodiment, In the range of the summary of this invention described in the claim, various Can be modified or changed.

DESCRIPTION OF SYMBOLS 1 Vehicle control apparatus 10 Engine 11 Starter 12 Starter relay 13 Battery 20 Engine ECU
30 Idle stop ECU (engine control unit, first ignition cylinder acquisition unit, crank angle acquisition unit, brake control unit)
40 Brake ECU
45 Brake pedal 46 Brake booster 47 Master cylinder 48 Negative pressure pipe 49 Wheel cylinder 50 Brake actuator 51 Master cut valve 52 Holding valve 53 Pressure reducing valve 54 Reservoir 55 Hydraulic pump 56 Motor 57 Accumulator 60 Vehicle speed sensor 70 Negative pressure sensor 80 MC pressure sensor 90 Crank angle sensor 92 Rotor 92a Teeth 92b Missing teeth

Claims (1)

An engine having a plurality of cylinders as a driving force source of the vehicle;
Engine control that automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when a predetermined start condition including a brake release operation is satisfied after the stop condition is satisfied And
A first ignition cylinder acquisition unit that acquires which of the plurality of cylinders is a first ignition cylinder that is initially ignited when the engine is automatically started;
A crank angle obtaining unit for obtaining a crank angle in the first ignition cylinder when the engine is automatically stopped;
A brake control unit that holds a predetermined braking force acting on the vehicle after the brake release operation included in the start condition is performed while the vehicle is stopped;
The brake control unit
The braking force is varied according to the crank angle,
Vehicle control device.

Images