Vehicle control unit

Abstract

Vehicle control unit, which includes the following: a deceleration level control unit (407) that controls a deceleration level of a vehicle (100), wherein If, during the journey of the vehicle (100), which is traveling with a disengaged power transmission mechanism between a power engine and wheels, a deceleration request is made and the power engine is started by engaging the power transmission mechanism, the deceleration level of the vehicle (100) is controlled such that the deceleration level becomes a target deceleration level, which is calculated from a first target deceleration level and a second target deceleration level, wherein The first target deceleration level is generated after the engagement of the power transmission mechanism is complete, and is based on a power machine braking system, and the second target slowdown level is generated in response to the slowdown request, whereby the deceleration level of the vehicle (100) corresponding to a braking torque, which is caused by the first target deceleration level and by the second target deceleration level, is reduced by a modified first target deceleration level.

Description

Technical area

[0001] The present invention relates to a vehicle control device, and more particularly to a vehicle control device that controls a deceleration level of a vehicle when, during an automatic stop of an engine, the engine is restarted by engaging a power transmitting mechanism between the engine and the wheels. State of the art

[0002] In recent years, in order to improve fuel economy, an automatic engine stop / start system that automatically stops an engine when a vehicle is stopped and restarts the engine using a starter at the time of vehicle start-up has been widely adopted. Furthermore, JP 2006-200370 A (Patent Literature 1) proposes a technique in which the engine is automatically stopped when a predetermined condition for automatic engine stop (for example, a state where an accelerator pedal is not depressed for a predetermined time or more) is met during vehicle travel, and the power transmission path between the engine and the wheels is disengaged, so that the vehicle coasts while minimizing engine speed reduction, thereby further reducing fuel consumption.

[0003] Furthermore, in JP 5 531 915 B2 (Patent Literature 2), a technique is proposed in which a starting clutch is ready in a half-engagement state when the generation of the final engine restart request is predicted based on an operation amount of a brake pedal, the vehicle speed, and the like during an eco-running operation in which the fuel supply is stopped and the vehicle is caused to run by coasting, thereby improving the acceleration responsiveness.

[0004] Patent 3 shows a vehicle control device and a vehicle control method including a controller. Furthermore, the controller of Patent 3 is configured to allow engine cranking by increasing clutch torque at a time when a deceleration request is detected during coasting.

[0005] PTL 4 shows a vehicle control system. Furthermore, the vehicle control system of PTL 4 is applied to a vehicle having an engine with a plurality of cylinders, a power transmission path between the engine and drive wheels, and a clutch device. In detail, PTL 4 describes an adaptation of the power transmission path.

[0006] PTL 5 shows a vehicle travel control unit. PTL 5 also addresses the fuel economy of a vehicle during coasting. In detail, PTL 5 proposes maintaining brake vacuum when braking is necessary.

[0007] PTL 6 shows a brake control system. Furthermore, PTL 6 describes the adjustment of the engine brake torque reduction amount so that the variation in the torque converter transmission torque becomes small. Citation listPatent literature PTL 1: JP 2006-200370 A PTL 2: JP 5531915 B2 PTL 3: DE 10 2015 113 299 A1 PTL 4: DE 11 2012 006 619 T5 PTL 5: DE 11 2012 007 072 T5 PTL 6: JP 2005- 313 831 A Summary of the inventionTechnical problem

[0008] When restarting (cranking) is initiated by the starter in the coasting state described above, the starter is activated and cranking is initiated at the time when the engine speed reaches the level at which the starter and the engine can be engaged. However, as the number of restarts and the number of starter activations increases, the durability of the starter decreases. In view of the above, when the wheels have sufficient driving force, the power transmission path between the stopped engine and the drive wheels is engaged, so that kinetic energy of the vehicle is transferred to the engine to start it, thereby enabling the engine to be restarted (cranked) without activating the starter.However, since the power transmission path is engaged when the engine is stopped, the actual deceleration level increases relative to the deceleration level required by a driver or the vehicle. Consequently, there may be a problem of degraded drivability.

[0009] The present invention has been made in view of the problems described above, and it is an object of the present invention to provide a vehicle control device capable of preventing deterioration of drivability during coasting, wherein an engine is automatically stopped and a power transmission path between the engine and the wheels is disengaged. Solution to the problem

[0010] In order to solve the problems described above, a vehicle control device according to the present invention includes a deceleration level control unit that controls a deceleration level of a vehicle such that, during travel of the vehicle continuing to travel with a power transmission mechanism between an engine and wheels disengaged, when a deceleration request is performed and the engine is started by engagement of the power transmission mechanism, the deceleration level becomes a target deceleration level calculated from a first target deceleration level generated after engagement of the power transmission mechanism is completed and a second target deceleration level generated in response to the deceleration request. Advantageous effects of the invention

[0011] As described above, according to the present invention, it becomes possible to provide a vehicle control device capable of preventing the deterioration of drivability during coasting, wherein the engine is automatically stopped and the power transmission path between the engine and the wheels is disengaged.

[0012] Other configurations, actions and effects of the present invention will be described in detail in the following embodiments. Brief description of the drawings [ Fig. 1] Fig. 1 is an example of an overall configuration of a vehicle including a vehicle control device according to the present invention. [ Fig. 2] Fig. 2 is an example of an internal configuration of the vehicle control device according to the present invention. [ Fig. 3] Fig. 3 is an example of the behavior of a vehicle deceleration level in a case where a deceleration request is performed and an engine 101 is started by engagement of a clutch 130, with respect to the vehicle control device according to the present invention. [ Fig. 4] Fig. 4 is an exemplary control block configuration of an ECU 110 of the vehicle control device according to the present invention. [ Fig. 5] Fig. 5 is an exemplary detailed block of a block 407 of the vehicle control device according to the present invention. [ Fig. 6] Fig. 6 is an exemplary flowchart of a block 401 of the vehicle control system according to the present invention. [ Fig. 7] Fig. 7 is an exemplary flowchart of step 403 of the vehicle control device according to the present invention. [ Fig. 8] Fig. 8 is an exemplary flowchart of step 703 of the vehicle control device according to the present invention. [ Fig. 9] Fig. 9 is an exemplary flowchart of a block 404 of the vehicle control system according to the present invention. [ Fig. 10] Fig. 10 is an exemplary flowchart of a block 405 of the vehicle control system according to the present invention. [ Fig. 11] Fig. 11 is an exemplary flowchart of a block 406 of the vehicle control system according to the present invention. [ Fig. 12] Fig. 12 is an exemplary flowchart of block 406 of the vehicle controller according to the present invention. [ Fig. 13] Fig. 13 is an exemplary flowchart of a block 501 of the vehicle control system according to the present invention. [ Fig. 14] Fig. 14 is an example of the behavior of the vehicle deceleration level in the case where the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, with respect to the vehicle control device according to the present invention. [ Fig. 15] Fig. 15 is an exemplary flowchart of a block 502 of the vehicle controller according to the present invention. [ Fig. 16] Fig. 16 is an example of the behavior of the vehicle deceleration level in the case where the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, with respect to the vehicle control device according to the present invention. [ Fig. 17] Fig. 17 is an exemplary flowchart of a block 503 of the vehicle control system according to the present invention. [ Fig. 18] Fig. 18 is an example of an oxygen storage amount in a catalyst in the case where the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, relating to the vehicle control device according to the present invention. [ Fig. 19] Fig. 19 is an exemplary flowchart of a block 408 of the vehicle controller according to the present invention. Description of embodiments

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First embodiment

[0014] A first embodiment of the present invention will be described with reference to Fig. 1 to 13 described. Fig. 1 is an example of an overall configuration of a vehicle including a vehicle control device according to the present invention.

[0015] In Fig. 1, a vehicle 100 includes an engine body 101 (also simply referred to as an internal combustion engine or engine) as a driving power source and a torque converter 102 provided on an output side of the engine 101. A transmission 103 is coupled to an output side of the torque converter 102. A type of the engine 101 may be any driving power source that causes the vehicle 100 to travel, and examples thereof include a port-injection type gasoline engine or an in-cylinder injection type gasoline engine and a diesel engine. Regarding a structure of the engine 101, it may be a reciprocating engine or a Wankel-type rotary engine.

[0016] Further, the engine 101 includes a starter 104 and a generator 105 that supplies electric power to the vehicle 100. The starter 104 may be, for example, a starter motor including a DC motor, a gear mechanism, and a gear push mechanism. The starter 104 is driven by the electric power supplied from a power source 106 and starts the engine 101 based on a start request. With respect to the power source 106, for example, a lead-acid battery may be suitably used, and various types of secondary batteries such as a lithium-ion secondary battery or storage batteries such as a capacitor may be used. Further, the generator 105 may be, for example, an alternator including an induction generator, a rectifier, and a voltage adjusting mechanism.The power source 106 stores the electrical power generated by the generator 105 and supplies the electrical power to electrical vehicle components such as the starter 104, a headlight (not shown), and various controllers.

[0017] The engine 101 also includes a crankshaft 107. The crankshaft 107 is provided on one side thereof with a signal plate 108 having a predetermined pattern formed thereon for detecting a crank angle signal, whereas on the other side of the crankshaft 107, a ring gear integral with a drive plate (not shown) for transmitting the drive force to the transmission is provided. A crank angle sensor 109, which detects irregularities in the pattern of the signal plate 108 and outputs a pulse signal, is mounted near the signal plate 108. Based on the pulse signal output from the crank angle sensor 109, an engine control unit (hereinafter referred to as ECU) 110 calculates a rotational speed (engine speed) of the engine 101.

[0018] Further, as intake system components of the engine 101, an intake manifold 111 that distributes intake air to each cylinder, a throttle valve 112, an air flow sensor 113, and an air cleaner 114 are mounted. The throttle valve 112 is an electrically controlled throttle device that controls an optimal throttle valve opening degree by calculating and outputting the optimal throttle opening degree using the ECU 110. The optimal throttle opening degree is calculated based on a signal from an accelerator pedal sensor 116 that detects a depression amount of an accelerator pedal 115, a signal from a brake pedal sensor 118 that detects a depression amount of a brake pedal 117, a signal from a vehicle speed sensor 120 that detects the vehicle speed from a rotational speed of wheels 119L and 119R, and other signals sent from each of other sensors.The air flow sensor 113 measures an air flow rate drawn in by the air cleaner 114 and outputs the air flow rate to the ECU 110. The ECU 110 calculates a fuel amount corresponding to the measured air amount and outputs the fuel amount to a fuel injection valve 121 as a valve opening timing. Regarding a valve opening timing, fuel injection is started at a predetermined timing set by the ECU 110 based on the signal from the crank angle sensor 109. As a result of this operation, the intake air and the fuel injected from the fuel injection valve 121 are mixed within a cylinder of the engine 101, thereby forming an air-fuel mixture. An ignition timing of the air-fuel mixture is also set by the ECU 110 based on the signal from the crank angle sensor 109.The air / fuel mixture within the cylinder is ignited by a spark plug 123, which is excited via an ignition coil 122, causing a combustion explosion.

[0019] The engine 101 also transfers the kinetic energy obtained by the above-described combustion explosion to the crankshaft 107 to generate rotational drive force. The drive plate (not shown) is mounted on the transmission side of the crankshaft 107 and is directly connected to the input side of the torque converter 102. On the other hand, the output side of the torque converter 102 is input to the transmission 103.The transmission 103 is a transmission body with a step-variable transmission mechanism or a belt-and-pulley type continuously variable transmission mechanism controlled by a transmission control unit (hereinafter referred to as TCU) 124 to determine a correct transmission gear or gear ratio based on engine information (engine speed, vehicle speed, and throttle opening degree) and gear range information 126 of a gear shift lever 125, thereby controlling an optimal transmission gear ratio. The transmission gear ratio control is performed by controlling the hydraulic pressure of the transmission using a mechanical oil pump 127 while the engine 101 is started and using an electric oil pump 128 while the engine 101 is stopped.Furthermore, a clutch mechanism 130 is provided between the transmission mechanism and a differential mechanism 129. The clutch mechanism 130 is engaged when the drive force is transmitted from the transmission mechanism to the differential mechanism 129 to drive the wheels 119, whereas the clutch mechanism 130 is disengaged when a reverse drive force is disconnected from the wheels 119, so that the reverse drive force is not transmitted to the transmission mechanism.

[0020] Further, the wheels 119L and 119R are provided with brake disc rotors 131L and 131R and brake pads 132L and 132R, which ensure braking force of the wheels 119L and 119R. When the brake pedal 117 is depressed, a depression force is transmitted to a master cylinder 134 through a brake booster 133. Along with this, brake fluid (brake oil) filling the brake pipe 135 is pushed out from the master cylinder 134, and the hydraulic pressure in a brake pipe 135 is changed, which is detected by a hydraulic unit (hereinafter referred to as HU) 136. The HU 136 can brake the wheels 119L and 119R by controlling the brake pads 132L and 132R by actuating the hydraulic pressure in a brake pipe 137 filled with brake fluid (brake oil) based on the detected hydraulic pressure. A drum brake can be used as the braking device for the wheels 119L and 119R.Furthermore, instead of the hydraulic ones that can be actuated according to the depression amount of the brake pedal 117, the brake pads 132L and 132R may be those provided with an electric actuator mechanism that can be actuated by a command value from the HU 136.

[0021] When the vehicle 100 is traveling, the clutch 130 is disengaged to cut off the reverse drive force, and the engine 101 is stopped, thereby creating a state where running resistance is minimized. This can improve fuel economy.

[0022] Fig. 2 is an example of an internal configuration of the vehicle control device according to the present embodiment. Note that in the present embodiment, the ECU 110 is treated as part of the vehicle control device. Therefore, in the present embodiment, the on-board control device is a combination of the ECU 110, the TCU 120, and the HU 136. In the ECU 20, an input / output unit (I / O unit) 102 is set within a central processing unit (CPU) 201. The I / O unit 202 converts electrical signals from each sensor arranged in the engine into signals for digital calculation processing and also converts control signals for digital calculation into drive signals of an actual actuator.A crank angle sensor 203, an intake air flow sensor 204, an intake pipe pressure sensor 205, a vehicle speed sensor 206, an accelerator pedal sensor 207, a brake pedal sensor 208, and an ignition switch 209 are input to the I / O unit 202. Output signals from the CPU 201 are transmitted to fuel injection valves 211 to 214 and ignition coils 215 to 218 via a driver 210.

[0023] Hereinafter, a problem to be solved by the vehicle control device according to the present embodiment will be described with reference to Fig. 3. It should be noted that Fig. 3 is an example of the behavior of a vehicle deceleration level in a case where a deceleration request is performed and the engine 101 is started by engagement of the clutch 130, with respect to the vehicle control device according to the present embodiment.

[0024] In Fig. In FIG. 3, a horizontal axis represents time, and a vertical axis represents the accelerator pedal opening degree 301, a brake pedal depression amount 302, a clutch engagement command 303, a fuel injection command 304, an engine speed 305, a braking torque 306, a vehicle deceleration level 307, and a brake device hydraulic pressure 308. At a time 309 during vehicle travel, an automatic engine stop condition based on an accelerator pedal off state is satisfied, with the accelerator pedal opening degree 301 being zero. At this time, the clutch 130 is disengaged by the clutch engagement off command 303, and fuel injection is stopped by the fuel injection off command 304.Consequently, the engine 101 enters a state where rotation cannot be maintained autonomously, causing the engine speed 305 to become zero at a time 310 and stopping the engine.

[0025] At this time, the vehicle 100 is coasting, and the vehicle deceleration level 307 is generated only by the running resistance. If, at a time 311 during coasting, the driver's operation causes the brake pedal depression amount 302 to exceed zero, that is, when the driver depresses the brake pedal 117, then there may be a case where the driver, in addition to the deceleration request, wishes to express a request to stop coasting, that is, a request to transition to a state where the engine 101 is restarted and the clutch 130 is engaged. At this time, the engine 101 is started by activating the starter 104, and fuel injection is restarted by the fuel injection command 304 being turned on, thereby allowing the engine 101 to be restarted.

[0026] Meanwhile, since the clutch 130 is disengaged at time 309 and thereafter, at time 311, the clutch 130 is engaged by the clutch engagement command 303 being enabled without activating the starter 104, and the kinetic energy of the coasting vehicle 100 is transferred to the engine 101, allowing the engine 101 to be restarted. At this time, the braking torque 306 is generated by a braking torque generated after the engagement of the clutch 130 is complete and another braking torque generated in response to the deceleration request generated by the depressing operation of the brake pedal 117.

[0027] In this case, however, engagement is performed in a state where the engine speed 305 is zero, that is, in a state where a deviation occurs between the engine speed and the vehicle speed (wheel speed), whereby the braking torque 306 rapidly increases at a time immediately after the time 311. Consequently, the vehicle deceleration level 307 also rapidly increases, so that what is called engagement shock is increased, thereby deteriorating drivability. In view of the above, an object of the present embodiment is to provide a vehicle control device capable of controlling a deceleration level of the vehicle 100 based on the vehicle speed when the engine 101 is started by engagement of the clutch 130.

[0028] Hereinafter, the vehicle control device according to the present embodiment will be described with reference to Fig. 4 to 13. It should be noted that Fig. 4 is a block diagram illustrating a control configuration of a central processing unit (CPU) 201 included in the vehicle control device (ECU 110) shown in Fig. 1 is shown.

[0029] In Fig. 4, an automatic engine stop determination unit 401 included in the CPU 201 of the ECU 110 determines an automatic engine stop based on an ignition switch, the vehicle speed, a brake pedal depression amount, clutch engagement information acquired from an output of the TCU 124, an accelerator pedal opening degree, and engine restart request determination information determined in a block 403 to be described later. Here, the clutch engagement information indicates information about the engagement / disengagement of the clutch 130 controlled by the TCU 124 based on a clutch engagement amount calculated by a deceleration level control unit 407 to be described later. When an automatic stop is determined by the automatic engine stop determination unit 401, as at time 309 in Fig. 3, control is performed such that the engagement of the clutch 130 is turned off and also the fuel injection of the fuel injection valve 121 is stopped, whereby the engine speed becomes zero and the automatic stop is performed.

[0030] Fig. 6 is an exemplary flowchart of the automatic engine stop determination unit 401 included in the CPU 201 of the ECU 101 shown in Fig. 4. In step 601, the ignition switch, vehicle speed, brake pedal depression amount, clutch engagement information, and accelerator pedal opening degree are read. In step 602, it is determined whether the ignition switch is on. If the determination is made, the process proceeds to step 603 to be described later. Otherwise, the process proceeds to step 610 to be described later. In step 603, it is determined whether the vehicle speed is equal to or more than a predetermined value A. If the determination is made, the process proceeds to step 604 to be described later. Otherwise, the process proceeds to step 610 to be described later. Here, the predetermined value A is set to, for example, a value with which to determine the coasting performance of the vehicle 100, whereby the engine 101 is automatically stopped and the clutch 130 is disengaged.

[0031] In step 604, it is determined from the brake pedal depression amount whether the brake is off. If the determination is made, the process proceeds to step 605 to be described later. Otherwise, the process proceeds to step 610 to be described later. In step 605, an elapsed time of an accelerator pedal off state is calculated from the accelerator pedal opening degree. The elapsed time is reset to zero if the accelerator pedal is on. In step 606, it is determined whether the elapsed time of the accelerator pedal off state is equal to or more than a predetermined time B. If the determination is made, the process proceeds to step 607 to be described later. Otherwise, the process proceeds to step 610 to be described later.Here, the predetermined time B is set to, for example, a value with which the accelerator-off state established by the driver is determined as not being in a process of switching to a brake-on state.

[0032] In step 607, it is determined from the clutch engagement information whether the clutch 130 between the engine 101 and the wheels 119L and 119R is disengaged. If the determination is made, the process proceeds to step 608, which will be described later. Otherwise, the process proceeds to step 610, which will be described later. In step 608, it is determined whether the engine restart request exists. If the determination is made, the process proceeds to step 610, which will be described later. Otherwise, the process proceeds to step 609, which will be described later. In step 609, it is determined that the automatic engine stop condition is satisfied. In step 610, it is determined that the automatic engine stop condition is not satisfied.

[0033] A system restart request determination unit 402 determines, during the automatic engine stop, whether the engine needs to be started by engaging the clutch 130, regardless of the driver's operation of the brake pedal under at least one of the following situations, where (1) performance deterioration or abnormality detection occurs with respect to a system component or a function of the vehicle, (2) a request for air conditioning operation occurs, (3) a request for power generation occurs, and (4) a request for increasing the deceleration level of the vehicle to avoid a collision with a front object of the vehicle, based on external detection information.

[0034] That is, although Fig. 3 illustrates the case where the engine is restarted under a condition where the driver depresses the brake pedal after the engine is automatically stopped, but the present embodiment is not limited to such a case. In addition to the above case, when the above-described situations (1) to (4) occur during the automatic engine stop, the system restart request determination unit 402 detects such situations, and control is performed such that the clutch 130 is engaged by a clutch engagement restart request determination unit 404 and the engine is also restarted by an engine restart request determination unit 403.

[0035] According to the Fig. 7, the engine restart request determination unit 403 determines the engine restart request from the automatic engine stop determination information, the accelerator pedal opening degree, the clutch engagement information acquired from the output of the TCU 124, the brake pedal depression amount, and the system restart request determination information.

[0036] Fig. 7 is an exemplary flowchart of the engine restart request determination unit 403 included in the CPU 201 of the ECU 110 shown in Fig. 4. In step 701, the accelerator pedal opening degree, the clutch engagement information, and the brake pedal depression amount are read. In step 702, it is determined whether the engine is automatically stopped. If the determination is made, the process proceeds to step 703 to be described later. Otherwise, the process proceeds to step 707 to be described later. In step 703, the engine output request is determined. In step 704, it is determined whether there is an engine output request. If the determination is made, the process proceeds to step 705 to be described later. Otherwise, the process proceeds to step 707 to be described later.

[0037] In step 705, it is determined from the clutch engagement information whether the clutch 130 between the engine 101 and the wheels 119L and 119R is disengaged. If the determination is made, the process proceeds to step 706, to be described later. Otherwise, the process proceeds to step 707, to be described later. In step 706, it is determined that the engine restart request condition is satisfied. In step 707, it is determined that the engine restart request condition is not satisfied.

[0038] Fig. 8 is an exemplary flow chart of step 703 of the Fig. 7. In step 801, it is determined whether there is a system restart request. If the determination is made, the process proceeds to step 804, to be described later. Otherwise, the process proceeds to step 802, to be described later. In step 802, it is determined whether the accelerator pedal has been switched from off to on. If the determination is made, the process proceeds to step 804, to be described later. Otherwise, the process proceeds to step 803, to be described later. In step 803, it is determined whether the brake has been switched from off to on. If the determination is made, the process proceeds to step 804, to be described later. Otherwise, the process proceeds to step 805, to be described later. In step 804, it is determined that the engine output request condition is satisfied.In step 805, it is determined that the engine output request condition is not satisfied.

[0039] According to the Fig. 9, the clutch engagement restart request determination unit 404 determines a clutch engagement restart request from the engine restart request determination information, the vehicle speed, the brake pedal depression amount, the system restart request determination information, and the target deceleration level information calculated by a target deceleration level calculation unit 405 to be described later.

[0040] Fig. 9 is an exemplary flowchart of the clutch engagement restart request determination unit 404 included in the CPU 201 of the ECU 110 shown in Fig. 4. In step 901, the vehicle speed and the brake pedal depression amount are read. In step 902, it is determined whether the engine restart request exists. If the determination is made, the process proceeds to step 903, which will be described later. Otherwise, the process proceeds to step 908, which will be described later. In step 903, it is determined whether the brake has been switched from off to on. If the determination is made, the process proceeds to step 904, which will be described later. Otherwise, the process proceeds to step 906, which will be described later. In step 904, deceleration energy at the time of engagement is calculated from the target deceleration level and the vehicle speed.The deceleration energy at the time of engagement may be a value estimated from the kinetic energy according to a formula (1) or a value obtained by searching a predetermined map having axes representing the target deceleration level and the vehicle speed. [Formula 1] E=12MV2

[0041] Here, E represents the kinetic energy, M represents the vehicle weight, and V represents the vehicle speed.

[0042] In step 905, it is determined whether the deceleration energy in the engagement state is equal to or more than a predetermined value C. If the determination is made, the process proceeds to step 907 to be described later. Otherwise, the process proceeds to step 906 to be described later. Here, the predetermined value C is set to, for example, an energy value required to start the engine by clutch engagement. In step 906, it is determined whether the system restart request exists. If the determination is made, the process proceeds to step 907 to be described later. Otherwise, the process proceeds to step 908 to be described later. In step 907, it is determined that a clutch engagement restart request condition is satisfied. In step 908, it is determined that the clutch engagement restart condition is not satisfied.

[0043] According to the Fig. 10, the target deceleration level calculation unit 405 calculates the target deceleration level from the vehicle speed, the brake pedal depression amount, and the transmission gear ratio information acquired from the output of the TCU 124. The transmission gear ratio information indicates information about the transmission gear ratio controlled by the TCU 124. The target deceleration level indicates a deceleration level that should originally be intended at the time of engine restart with the clutch 130 engaged, which is represented by a vehicle deceleration level 313 in Fig. 3. However, when the clutch 130 is actually engaged and the engine is restarted, the engagement is performed in a state where the wheels 119 are traveling at a certain vehicle speed, with the engine speed being zero, thereby causing a sudden deceleration as indicated by the vehicle deceleration level 307 in Fig. 3 is specified.

[0044] Fig. 10 is an exemplary flowchart of the target deceleration level calculation unit 405 included in the CPU 201 of the ECU 110 shown in Fig. 4. In step 1001, the brake pedal depression amount, the vehicle speed, and the transmission gear ratio information are read. In step 1002, the engine speed at the time of clutch engagement is calculated from the vehicle speed and the transmission gear ratio information. The engine speed at the time of clutch engagement may be a value acquired by searching a predetermined map having axes representing the vehicle speed and the transmission gear ratio information. In step 1003, the power generation engine speed is calculated from a target generation voltage. In this step, in order to obtain a power generation amount required by the ECU 110 (target generation voltage), the power generation engine speed is calculated as the engine speed required to drive the generator 105.The power generation engine speed may be a value acquired by searching a predetermined table having an axis representing the target generation voltage. Incidentally, the power generation engine speed may include the engine speed required at a time when auxiliary machinery such as an air conditioner is operating.

[0045] The deceleration level calculation engine speed calculated in step 1004, such an engine speed being calculated from the engine speed at the time of clutch engagement and the power generation engine speed, may be an additional value of the engine speed at the time of clutch engagement and the power generation engine speed, or a value acquired by searching a predetermined map having axes representing the engine speed at the time of clutch engagement and the power generation engine speed. In step 1005, a first target deceleration level is calculated from the deceleration level calculation engine speed and the vehicle speed. The first target deceleration level may be a value obtained from the deceleration level α eestimated according to a formula (2), or a value acquired by searching a predetermined map having axes representing the deceleration level calculation engine speed and the vehicle speed. [Formula 2] αe=1MCdSV2−μg−g sinθ−FeM

[0046] Here M represents a vehicle weight, C d represents an air drag coefficient, S represents a front projected area of ​​the vehicle, V represents the vehicle speed, µ represents a rolling resistance coefficient, g represents the gravitational acceleration, θ represents a road gradient and F e represents an engine loss torque at the time of clutch engagement, with fuel injection into the engine stopped. Since the engine loss torque F evaries depending on the deceleration level calculation engine speed, a value obtained by searching a predetermined map having an axis representing the deceleration level calculation engine speed may be used. In step 1006, a second target deceleration level is calculated from the vehicle speed and the brake pedal depression amount. The second target deceleration level may be a value obtained by searching the predetermined map having the axes representing the vehicle speed and the brake pedal depression amount. In step 1007, a target deceleration level is calculated from the first target deceleration level and the second target deceleration level.The target deceleration level may be an additional value of the first target deceleration level and the second target deceleration level or a value acquired by searching a predetermined map having axes representing the first target deceleration level and the second target deceleration level.

[0047] As described above, since in reality a sudden deceleration is caused as indicated by the vehicle deceleration level 307 in Fig. 3, a vehicle deceleration level calculation unit 406 calculates the vehicle deceleration level of an actual vehicle from the transmission gear ratio information acquired from the output of the TCU 124, the vehicle speed, and the engine speed.

[0048] Fig. 11 is an exemplary flowchart of the vehicle deceleration level calculation unit 406 included in the CPU 201 of the ECU 110 shown in Fig. 4. In step 1101, the vehicle speed is read. In step 1102, a change in the vehicle speed per unit time is calculated and output as the vehicle deceleration level.

[0049] Fig. 12 is an exemplary flow chart of a block 406 in Fig. 4 with respect to the vehicle control device according to the present embodiment. In step 1201, the transmission gear ratio information, the vehicle speed, and the engine speed are read. In step 1202, the engine speed at the time of clutch engagement is calculated from the vehicle speed and the transmission gear ratio information. The engine speed at the time of clutch engagement may be a value acquired by searching the predetermined map having the axes representing the vehicle speed and the transmission gear ratio information. In step 1203, the vehicle deceleration level is calculated from the engine speed at the time of clutch engagement and the vehicle speed. The vehicle deceleration level may be a value obtained from the deceleration level α eestimated according to the formula (2), or a value obtained by searching a predetermined map having axes representing the engine speed at the time of clutch engagement and the vehicle speed.

[0050] Then, the vehicle deceleration level control unit 407 controls the deceleration level of the vehicle 100 based on the brake pedal depression amount, the target deceleration level information calculated by the target deceleration level calculation unit 405, the vehicle deceleration level information of the actual vehicle calculated by the vehicle deceleration level calculation unit 406, and the clutch engagement restart request determination information. For this purpose, the brake device hydraulic pressure, a target gear ratio, and the clutch engagement amount required to perform the control are determined. The vehicle deceleration level control unit 407 controls the hydraulic pressure of the brake device (although a detailed control method will be described later). Fig. 3 and Fig. 10), the target gear ratio ( Fig. 14 and Fig. 15) or the clutch engagement degree ( Fig. 16 and Fig. 17), so that the vehicle deceleration level of the actual vehicle calculated by the vehicle deceleration level calculation unit 406 becomes the target deceleration level calculated by the target deceleration level calculation unit 405.

[0051] As described in a fourth embodiment, a fuel injection amount control unit 408 controls a fuel injection amount to reduce catalyst performance. Although details are described in the fourth embodiment, the fuel injection amount control unit 408 controls the fuel injection amount based on the clutch engagement restart request determination information, the automatic engine stop determination information, an intake air amount, the intake pipe pressure, and the engine speed. Consequently, an operation amount of the fuel injection valve 121 required to perform the control is determined.

[0052] Fig. 5 is a diagram describing a detailed block configuration of the vehicle deceleration level control unit 407 shown in Fig. 4. The vehicle deceleration level control unit 407 controls an actual deceleration level through a brake device hydraulic pressure calculation unit 501, a target transmission gear ratio calculation unit 502, or a clutch engagement amount calculation unit 503 so that the vehicle deceleration level of the actual vehicle calculated by the vehicle deceleration level calculation unit 406 becomes the target deceleration level calculated by the target deceleration level calculation unit 405. The deceleration level can be controlled by any one or a combination of the above-mentioned components.

[0053] Specifically, the brake device hydraulic pressure calculation unit 501 determines the brake device hydraulic pressure required to control the deceleration level of the vehicle 100 from the brake pedal depression amount, the target deceleration level information, the vehicle deceleration level information, and the clutch engagement restart request determination information. The brake device hydraulic pressure is transmitted to the HU 136, and the HU 136 optimally controls the braking force of the brake based on the brake device hydraulic pressure and the engine-side information about the brake pedal depression amount.

[0054] The target gear ratio calculation unit 502 calculates the target gear ratio from the clutch engagement restart request determination information, the vehicle deceleration level information, the target deceleration level information, and the brake pedal depression amount. The target gear ratio is transmitted to the TCU 124, and the TCU 124 optimally controls the gear ratio based on the target gear ratio, the engine-side information (engine speed, vehicle speed, and throttle opening degree) calculated by the clutch engagement amount calculation unit 503 to be described later, which includes the clutch engagement amount, and the transmission-side information.

[0055] The clutch engagement amount calculation unit 503 calculates the clutch engagement amount from the clutch engagement restart request determination information, the vehicle deceleration level information, the target deceleration level information, and the brake pedal depression amount. The clutch engagement amount is transmitted to the TCU 124, and the TCU 124 optimally controls the clutch based on the engine-side information (engine speed, vehicle speed, and throttle opening degree) with the clutch engagement amount and the transmission-side information.

[0056] Fig. 13 is an exemplary flowchart of the brake device hydraulic pressure calculation unit 501 included in the CPU 201 of the ECU 110 shown in Fig. 5. In step 1301, the brake pedal depression amount is read. In step 1302, it is determined whether an elapsed time after the detection of a clutch engagement restart is within a predetermined time E. If the determination is made, the process proceeds to step 1303 to be described later. Otherwise, no special processing is performed, and the process of the present flowchart is terminated. The elapsed time is cleared when the clutch engagement restart is detected. Here, the predetermined time E is set, for example, to a value to determine that the clutch engagement is complete and to stop the generation of deceleration caused by the engagement.

[0057] In step 1303, it is determined whether the brake pedal depression amount is equal to or greater than a predetermined value D. If the determination is made, the process proceeds to step 1304, which will be described later. Otherwise, no special processing is performed, and the process of the present flowchart is terminated. Here, the predetermined value D is set to, for example, a brake pedal depression amount at which the hydraulic pressure of the brake device becomes operable. In step 1304, a hydraulic pressure of the brake device is calculated from the vehicle deceleration level and the target deceleration level.The brake device hydraulic pressure may be a value acquired by searching a predetermined table having an axis representing a deviation between the vehicle deceleration level and the target deceleration level, or a value acquired by searching a predetermined map having axes representing the vehicle deceleration level and the target deceleration level.

[0058] As described above, the CPU (control unit) 201 of the ECU 110 according to the present embodiment includes the deceleration level control unit 407 that controls the actual deceleration level of the vehicle 100 so that during the travel of the vehicle 100 continuing to travel with the clutch 130 disengaged between the engine 101 and the wheels 119L and 119R, when the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, the deceleration level becomes the target deceleration level calculated from the first target deceleration level generated after the engagement of the clutch 130 is completed and the second target deceleration level generated in response to the deceleration request.

[0059] A method for calculating the first target deceleration level and the second target deceleration level is as described above. The first target deceleration level is based on what is called engine braking, and the second target deceleration level is based on the brake pedal depression amount. Although these deceleration levels are ideal, in reality, sudden deceleration is caused, as indicated by the vehicle deceleration level 307 in Fig. 3, whereby drivability can be reduced. In view of the above, the deceleration level control unit 407 performs control so that the vehicle deceleration level of the actual vehicle calculated by the vehicle deceleration level calculation unit 406 becomes the target deceleration level calculated by the target deceleration level calculation unit 405.

[0060] At time 311 in Fig. 3, when the clutch 130 is engaged by the clutch engagement command 303 being enabled and the engine 101 is restarted, the braking torque may be reduced from the braking torque 306 to the braking torque 312. Consequently, the deceleration level of the vehicle 100 caused by the first target deceleration level generated after the engagement of the clutch 130 is complete and the second target deceleration level generated in response to the deceleration request may be reduced from the vehicle deceleration level 307 to the vehicle deceleration level 313, thereby preventing degradation of drivability.

[0061] Since the engine 101 is restarted by engaging the clutch 130, it is not necessary to restart the engine 101 (perform cranking) by activating the starter 104. Consequently, the number of activations of the starter 104 can be reduced, thereby preventing deterioration of the durability of the starter 104.

[0062] In the configuration described above, it is preferable that the deceleration request be generated by the driver's operation of the brake pedal. When the deceleration request is generated by the depressing operation of the brake pedal 117, the engine 101 is restarted by the engagement of the clutch 130, so that the engine speed is increased from the starting state. Consequently, it is not necessary to restart fuel injection, which can reduce fuel consumption.

[0063] According to this configuration, at time 311 in Fig. 3, the deceleration level of the vehicle 100 is controlled in response to the driver's deceleration request based on the operation of the brake pedal 117, whereby the deceleration level can be controlled according to the driver's deceleration intention.

[0064] Furthermore, in the configuration described above, it is preferable that the generator 105 that generates electric power according to the rotation of the engine 101 is provided, and the deceleration level control unit 407 controls the deceleration level caused by the first target deceleration level and the second target deceleration level based on the power generation amount of the generator 105.

[0065] As indicated in step 1002, the rotational speed of the engine 101 required to engage the clutch 130 is originally calculated from the vehicle speed and the transmission gear ratio information (engine rotational speed in the clutch engagement state in step 1002). Meanwhile, when the generator 105 is generating electric power, it is necessary to increase the rotational speed of the engine 101 according to the power generation amount. This required rotational speed is the power generation engine rotational speed in step 1003. This is requested by the ECU 110 side based on a voltage drop occurrence of the battery 106 and the like. Therefore, for example, if the power generation engine rotational speed is higher than the engine rotational speed at the time of clutch engagement, the rotational speed of the engine 103 increases after the engagement of the clutch 130 is completed, and the deceleration level increases.In view of the above, based on the processing in steps 1004 and 1005, the first target deceleration level is calculated in consideration of the power generation engine speed.

[0066] Although the method for calculating the first target deceleration level is as described above, that is, the first target deceleration level is based on what is called engine braking, specifically, the first target deceleration level is set by previously subtracting the deceleration level caused by the engine speed at the time of clutch engagement, the power generation engine speed, and the transmission gear ratio from the previous deceleration level. Then, the deceleration level control unit 407 controls the vehicle deceleration level of the actual vehicle calculated by the vehicle deceleration level calculation unit 406 so that the deceleration level becomes the target deceleration level calculated by the modified first target deceleration level and the second target deceleration level.

[0067] Specifically, in the configuration described above, it is preferable that the deceleration level control unit 407 controls a braking amount of the braking devices for the wheels 119L and 119R so that the deceleration level of the vehicle 100 becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level.

[0068] According to the configuration described above, the deceleration level of the vehicle 100 can be controlled by controlling the braking amount of the braking devices (braking devices) for the wheels 119L and 119R, such as the brake pads 132L and 132R.

[0069] In the configuration described above, it is also preferable that the deceleration level control unit 407 controls the hydraulic pressure generated by the operation of the brake pedal 117 or the hydraulic pressure by which the brake pads 132L and 132R are actuated so that the deceleration level of the vehicle 100 becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level.

[0070] According to the configuration described above, the hydraulic pressure generated by the operation of the brake pedal 117 or the hydraulic pressure by which the brake pads 132L and 132R are actuated is reduced from the brake device hydraulic pressure 308 to a brake device hydraulic pressure 314 which is Fig. 3, so that the braking force of the braking devices for the wheels 119L and 119R can be controlled, whereby the deceleration level of the vehicle 100 can be controlled. Second embodiment

[0071] A second embodiment of the present invention will be described with reference to Fig. 14 and Fig. 15 described.

[0072] A problem to be solved by a vehicle control device according to the present embodiment will be described below with reference to Fig. 14, but the contents are similar to those of the first embodiment. It should be noted that Fig. 14 is an example of the behavior of a vehicle deceleration level in a case where a deceleration request is performed and an engine 101 is started by engagement of a clutch 130, with respect to the vehicle control device according to the present invention.

[0073] At a time 1406 while driving a vehicle which is in Fig. 14, a vehicle 100 coasts to a stop in such a manner that the clutch 130 is disengaged and an engine is stopped, with the engine speed 1403 being zero. When, at a time 1407 during the coasting, a brake pedal depression amount 1401 caused by a driver's operation exceeds zero, in other words, when a brake pedal 117 depression operation is performed by the driver, the clutch 130 is engaged without starting a starter 104 based on an enabled clutch engagement command 1402, thereby restarting the engine 101. At this time, a braking torque 1404 is generated by a braking torque generated after engagement of the clutch 130 is completed and another braking torque generated in response to the deceleration request generated by the stepping-down operation of the brake pedal 117.

[0074] In this case, however, engagement is performed in a state where the engine speed 1403 is zero, that is, in a state where a deviation occurs between the engine speed and the vehicle speed (wheel speed), whereby the braking torque 1404 rapidly increases at a time immediately after the timing 1407 at the start of engagement. Consequently, a vehicle deceleration level 1405 also rapidly increases, so that what is called engagement shock is increased, thereby deteriorating drivability. In view of the above, an object of the present embodiment is to provide a vehicle control device capable of controlling a deceleration level of the vehicle 100 based on the vehicle speed when the engine 101 is started by engagement of the clutch 130.

[0075] Fig. 15 is an exemplary flowchart of a target gear ratio calculation unit 502 used in Fig. 5, with respect to the vehicle control device according to the present embodiment. In step 1501, the brake pedal depression amount is read. In step 1502, it is determined whether an elapsed time after the detection of a clutch engagement restart is within a predetermined time E. If the determination is made, the process proceeds to step 1503 described later. Otherwise, no special processing is performed, and the process of the present flowchart is terminated. The elapsed time is cleared if the clutch engagement restart is detected. The predetermined value E is set, for example, to a value similar to that in step 1502 described above. In step 1503, it is determined whether the brake pedal depression amount is less than a predetermined value D. If the determination is made, the process proceeds to step 1504 described later.Otherwise, no special processing is performed, and the process of the present flowchart is terminated. The predetermined value D is set, for example, to a value similar to that in step 1303 described above.

[0076] In step 1504, a target gear ratio is calculated from the vehicle deceleration level and a target deceleration level. Here, a method for calculating a first target deceleration level and a second target deceleration level is described as in the first embodiment. The first target deceleration level is based on what is called engine braking, and the second target deceleration level is based on the brake pedal depression amount. Although these deceleration levels are ideal, in reality, a sudden deceleration is caused, as indicated by the vehicle deceleration level 1405 in Fig. 14, whereby drivability can be reduced. In view of the above, the deceleration level control unit 407 performs control so that the vehicle deceleration level of the actual vehicle calculated by the vehicle deceleration level calculation unit 406 becomes the target deceleration level calculated by the target deceleration level calculation unit 405.

[0077] The target gear ratio may be a value obtained by searching a predetermined table with an axis representing a deviation between the vehicle deceleration level and the target deceleration level, or a value obtained by searching a predetermined map with axes representing the vehicle deceleration level and the target deceleration level. As in Fig. 14, specifically, control is performed such that the clutch 130 is engaged by a clutch engagement restart request determining unit 404 after the gear ratio is reduced by the target gear ratio calculating unit 502 of the deceleration level control unit 407, and the engine is also restarted by an engine restart request determining unit 403.

[0078] Since the transmission gear ratio, as indicated by the transmission gear ratio 1412, is reduced relative to the transmission gear ratio 1411 of a reference example to which the present embodiment is not applied, an increase rate of the engine speed after the engine restart, as indicated by the engine speed 1413, is reduced relative to the engine speed 1403 of the reference example. Therefore, the braking torque when the clutch 130 is engaged, as indicated by the braking torque 1409, can be made smaller than the braking torque 1404 of the reference example, whereby the vehicle deceleration level, as indicated by the vehicle deceleration level 1410, can be made smaller than the vehicle deceleration level 1405 of the reference example.

[0079] As described above, the vehicle control device according to the present embodiment includes the deceleration level control unit 407 that controls the deceleration level of the vehicle 100 such that, during the travel of the vehicle 100 continuing to travel with the clutch 130 disengaged between the engine 101 and the wheels 119L and 119R, when the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, the deceleration level becomes the target deceleration level calculated from the first target deceleration level generated after the engagement of the clutch 130 is completed and the second target deceleration level generated in response to the deceleration request.The deceleration level control unit 407 controls the gear ratio of the transmission 103 coupled to the engine 101 using the target gear ratio calculation unit 502 so that the deceleration level of the vehicle 100 becomes the target deceleration level calculated from the first target deceleration level and the second deceleration level.

[0080] According to the configuration described above, when the engine 101 is restarted by engaging the clutch 130, the gear ratio of the transmission 130 coupled to the engine 101 is changed from the gear ratio 1411 to the gear ratio 1412 shown in Fig. 14, so that the braking torque of the vehicle 100, which rapidly increases at a time 1408 immediately after engagement, can be reduced from the braking torque 1404 to the braking torque 1409. Consequently, the deceleration level of the vehicle 100 generated after the engagement of the clutch 130 is complete can be reduced from the vehicle deceleration level 1405 to the vehicle deceleration level 1410, which is the target deceleration level, thereby preventing the deterioration of drivability. Third embodiment

[0081] A third embodiment of the present invention will be described with reference to Fig. 16 and Fig. 17 described.

[0082] A problem to be solved by a vehicle control device according to the present embodiment will be described below with reference to Fig. 16, but the contents are similar to those of the first embodiment. It should be noted that Fig. 16 is an example of the behavior of a vehicle deceleration level in a case where a deceleration request is performed and an engine 101 is started by engagement of a clutch 130, with respect to the vehicle control device according to the present invention.

[0083] At a time 1606 while driving a vehicle which is in Fig. 16, a vehicle 100 coasts to a stop in such a manner that the clutch 130 is disengaged and an engine is stopped, with the engine speed 1603 being zero. When, at a time 1607 during the coasting, a brake pedal depression amount 1601 caused by a driver's operation exceeds zero, in other words, when a brake pedal 117 depression operation is performed by the driver, the clutch 130 is engaged without starting a starter 104 based on an on clutch engagement command 1602, thereby restarting the engine 101. At this time, a braking torque 1604 is generated by a braking torque generated after engagement of the clutch 130 is completed and another braking torque generated in response to the deceleration request generated by the stepping-down operation of the brake pedal 117.In this case, however, the engagement is performed in a state where the engine speed 1603 is zero, that is, in a state where a deviation occurs between the engine speed and the vehicle speed (wheel speed), whereby the braking torque 1604 rapidly increases at a time immediately after the time 1607 at which the engagement is started. Consequently, a vehicle deceleration level 1605 also rapidly increases, so that what is called engagement shock is increased, thereby deteriorating drivability. In view of the above, an object of the present embodiment is to provide a vehicle control device capable of controlling a deceleration level of the vehicle 100 based on the vehicle speed when the engine 101 is started by engagement of the clutch 130.

[0084] Characteristics of the present embodiment described above will be described with reference to Fig. 17 described. Fig. 17 is an example flowchart of a block 503 in Fig. 5 relating to the vehicle control device as an object of the present invention. In step 1701, a brake pedal depression amount is read. In step 1702, it is determined whether an elapsed time after the detection of a clutch engagement restart is within a predetermined time E. If the determination is made, the process proceeds to step 1703 to be described later. Otherwise, no special processing is performed, and the process of the present flowchart is terminated. The elapsed time is cleared if the clutch engagement restart is detected. The predetermined value E is set, for example, to a value similar to that in step 1702 described above. In step 1703, it is determined whether the brake pedal depression amount is less than a predetermined value D. If the determination is made, the process proceeds to step 1704 to be described later.Otherwise, no special processing is performed, and the process of the present flowchart is terminated. The predetermined value D is set, for example, to a value similar to that in step 1303 described above. In step 1704, a clutch engagement amount is calculated from the vehicle deceleration level and a target deceleration level. The clutch engagement amount may be a value obtained by searching a predetermined table having an axis representing a deviation between the vehicle deceleration level and the target deceleration level, or a value obtained by searching a predetermined map having axes representing the vehicle deceleration level and the target deceleration level.

[0085] As shown in the above-mentioned drawings, the vehicle control device according to the present embodiment includes a deceleration level control unit 407 that controls the deceleration level of the vehicle 100 such that, during the travel of the vehicle 100 continuing to travel with the clutch 130 disengaged between the engine 101 and the wheels 119L and 119R, when the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, the deceleration level becomes the target deceleration level calculated from a first target deceleration level generated after the engagement of the clutch 130 is completed and a second target deceleration level generated in response to the deceleration request.

[0086] The deceleration level control unit 407 controls an engagement degree of the clutch 130 so that the deceleration level of the vehicle 100 becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level.

[0087] According to the configuration described above, when the engine 101 is restarted by engaging the clutch 130, the engagement amount of the clutch 130 is changed between time 1607 and time 1608 in Fig. 16 from a clutch engagement degree 1611 to a clutch engagement degree 1612, so that the braking torque of the vehicle 100, which increases rapidly at time 1608 immediately after engagement, can be reduced from the braking torque 1604 to the braking torque 1609. Consequently, the deceleration level of the vehicle 100, which is generated after the engagement of the clutch 130 is complete, can be reduced from the vehicle deceleration level 1605 to a vehicle deceleration level 1610, thereby preventing the deterioration of the drivability. This control is performed in blocks 405 and 407 based on control blocks included in Fig. 4. Specifically, the deceleration level caused by the first target deceleration level and the second target deceleration level is controlled according to the vehicle speed, whereby the braking torque 1609 and the vehicle deceleration level 1610 can be obtained.

[0088] In the configuration described above, it is also preferable that the deceleration level control unit performs the control such that the engagement degree of the clutch 130 is increased when the deceleration request is large, whereas the engagement degree of the clutch 130 is decreased when the deceleration request is small.

[0089] According to the configuration described above, when the engine 101 is restarted by engaging the clutch 130, the engagement degree of the clutch 130 is controlled according to the amount of the requested deceleration level, so that the deceleration level of the vehicle 100 at the time of engagement can be accurately controlled, whereby the deterioration of drivability can be prevented. Fourth embodiment

[0090] A fourth embodiment of the present invention will be described with reference to Fig. 18 and Fig. 19 described.

[0091] Hereinafter, a problem to be solved by a vehicle control device according to the present embodiment will be described with reference to Fig. 18. It should be noted that Fig. 18 is an example of an oxygen storage amount in a catalyst in a case where a deceleration request is performed and an engine 101 is started by engagement of a clutch 130, related to the vehicle control device according to the present invention.

[0092] In Fig. 18, a line 1801 represents an accelerator pedal opening degree, a line 1802 represents a brake pedal depression amount, a line 1803 represents a clutch engagement command, a line 1804 represents a fuel injection command, a line 1805 represents the engine speed, a line 1806 represents a braking torque, a line 1807 represents a vehicle deceleration level, and a line 1808 represents the oxygen storage amount in a catalyst. At a time 1809 during vehicle travel, an automatic engine stop condition is satisfied based on an accelerator pedal off state, with the accelerator pedal opening degree 1801 being zero. At this time, the clutch 130 is disengaged by the clutch engagement off command 1803, and fuel injection is stopped by the fuel injection off command 1804.As a result, the engine 101 enters a state where rotation cannot be sustained autonomously, causing the engine speed 1805 to become zero at a time 1810, and the engine to stop. At this time, the vehicle 100 coasts, and the vehicle deceleration level 1807 is generated only by running resistance. At a time 1811 during coasting, when a driver's operation causes the brake pedal depression amount 1802 to exceed zero, that is, when the driver depresses a brake pedal 117, then there may be a case where the driver, in addition to the deceleration request, wishes to express a request to stop coasting, that is, a request to transition to a state where the clutch 130 is engaged by restarting the engine 101.At this time, the engine 101 is started by activating a starter 104, and fuel injection is restarted by the enabled fuel injection command 1804, allowing the engine 101 to be restarted. Since the clutch 130 is disengaged at time 1809 and thereafter, at time 1811, the clutch 130 is engaged by the enabled clutch engagement command 1803 without activating the starter 104, and kinetic energy of the coasting vehicle 100 is transferred to the engine 101, allowing the engine 101 to be restarted. However, in this case, since the fuel injection command 1804 remains in a disabled state, fuel injection remains in a stopped state until, after the engine is restarted, at time 1812, when the engine speed 1805 reaches a fuel injection reactivation speed 1813.Along with this, since the oxygen storage amount in a catalyst 1808 reaches a maximum storage value 1814, the oxygen amount in the catalyst becomes excessive, and a reduction reaction is not caused in the catalyst at the time 1812 when fuel injection is restarted, thereby worsening exhaust emission. In view of the above, an object of the present embodiment is to provide a vehicle control device that starts fuel injection into the engine 101 when the engine 101 is started by engagement of the clutch 130.

[0093] Characteristics of the present embodiment described above will be described with reference to Fig. 19 described. Fig. 19 is an example flowchart of a block 409 in Fig. 4 relating to the vehicle control device as an object of the present invention. In step 1901, the engine speed, an intake air amount, and an intake pipe pressure are read. In step 1902, it is determined whether an elapsed time after the detection of a clutch engagement restart is within a predetermined time E. If the determination is made, the process proceeds to step 1904 to be described later. Otherwise, the process proceeds to step 1903 to be described later. The elapsed time is cleared if the clutch engagement restart is detected. The predetermined value E is set, for example, to a value similar to that in step 1902 described above. In step 1903, it is determined whether the engine is automatically stopped. If the determination is made, the process proceeds to step 1906 to be described later.Otherwise, no special processing is performed, and the process of the present flowchart is terminated. In step 1904, a target fuel injection amount is calculated from the engine speed and an engine load. The target fuel injection amount may be a value acquired by searching a predetermined map having axes representing the engine speed and the engine load. Here, the engine load may be represented by the intake pipe pressure converted through predetermined processing from an output of an intake pipe pressure sensor provided in an intake pipe, or an intake air amount measured by an intake air amount sensor such as a thermal air flow meter.In step 1905, an operation amount of a fuel injection valve is calculated from the target fuel injection amount, and a fuel injection amount of the engine is controlled based on this operation amount. In step 1906, the operation amount of the fuel injection valve is calculated with the target fuel injection amount set to zero, and the fuel injection amount of the engine is controlled based on this operation amount.

[0094] As shown in the above-mentioned drawings, the vehicle control device according to the present embodiment includes a deceleration level control unit 407 that controls the deceleration level of the vehicle 100 such that, during the travel of the vehicle 100 continuing to travel with the clutch 130 disengaged between the engine 101 and the wheels 119L and 119R, when the deceleration request is performed and the engine 101 is started by the engagement of the clutch 130, the deceleration level becomes the target deceleration level calculated from a first target deceleration level generated after the engagement of the clutch 130 is completed and a second target deceleration level generated in response to the deceleration request.When a restart request is generated by an operation of the brake pedal 117, a CPU (control unit) 201 included in the vehicle control device (ECU 110) controls an injector so that fuel injection into the engine 101 is started.

[0095] According to the configuration described above, at the time 1811 in Fig.18, when the restart request is generated by the operation of the brake pedal 117, fuel injection into the engine 101 is started by an on-fuel injection command 1815 and is stopped after a predetermined time, thereby reducing the oxygen storage amount in the catalyst from the oxygen storage amount in a catalyst 1808 to the oxygen storage amount in a catalyst 1816. Consequently, deterioration of catalyst performance can be prevented. Consequently, at time 1812 when the engine speed 1805 reaches the fuel injection reactivation speed 1813 when fuel injection is started by the on-fuel injection command 1815, the reduction reaction is performed in the catalyst, thereby preventing deterioration of exhaust emission.

[0096] The embodiments of the present invention have been described above. By combining the configuration described in a specific embodiment with the configuration of another embodiment, the actions and effects of each embodiment can be achieved. List of reference symbols 100 vehicles 101 Power Machine 103 gearboxes 104 starters 105 Generator 109 Crank angle sensor 110 Engine Control Unit (ECU) 111 intake manifold 112 throttle valve 113 Air flow sensor 115 Accelerator pedal 116 Accelerator pedal sensor 117 Brake pedal 118 Brake pedal sensor 119L and 119R wheels 120 Vehicle speed sensor 121 Fuel injection valve 124 Transmission Control Unit (TCU) 126 Gear range information 130 Clutch mechanism 132L and 132R brake pad 136 Hydraulic unit (HU) 203 Crank angle sensor 204 Intake air flow sensor 205 Inlet pipe pressure sensor 206 Vehicle speed sensor 207 Accelerator pedal sensor 208 brake pedal sensor 209 ignition switch 401 Determination unit for automatic engine stop 403 Engine restart request determination unit 404 Clutch engagement restart request determination unit 405 Target deceleration level calculation unit 406 Vehicle deceleration level calculation unit 407 Deceleration level control unit 408 Fuel injection quantity control unit

Claims

[1] Vehicle control device comprising: a deceleration level control unit (407) that controls a deceleration level of a vehicle (100), wherein when a deceleration request is made during travel of the vehicle (100) traveling with a disengaged power transmission mechanism between an engine and wheels and the engine is started by engaging the power transmission mechanism, the deceleration level of the vehicle (100) is controlled such that the deceleration level becomes a target deceleration level calculated from a first target deceleration level and a second target deceleration level, wherein the first target deceleration level is generated after engagement of the power transmission mechanism is complete and is based on engine braking, and the second target deceleration level is generated in response to the deceleration request, wherein the deceleration level of the vehicle (100) corresponding to a braking torque caused by the first target deceleration level and by the second target deceleration level is reduced by a modified first target deceleration level. [2] A vehicle control device according to claim 1, wherein the deceleration request is generated by the operation of a brake pedal (117) by a driver. [3] Vehicle control device according to claim 1, wherein the prime mover comprises a generator (105) which generates electrical power in accordance with the rotation of the prime mover, and the deceleration level control unit (407) modifies the first target deceleration level based on a power generation amount of the generator (105), and controls the deceleration level of the vehicle (100) such that the deceleration level becomes a target deceleration level calculated from the modified first target deceleration level and the second deceleration level. [4] The vehicle control device according to claim 1, wherein the deceleration level control unit (407) controls the deceleration level of the vehicle (100) such that the deceleration level becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level by controlling a braking amount of braking devices for the wheels. [5] The vehicle control device according to claim 1, wherein the deceleration level control unit (407) controls the deceleration level of the vehicle (100) such that the deceleration level becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level by controlling a hydraulic pressure generated by an operation of the brake pedal (117) or a hydraulic pressure by which a brake pad is operated. [6] The vehicle control device according to claim 1, wherein the deceleration level control unit (407) controls the deceleration level of the vehicle (100) such that the deceleration level becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level by controlling a transmission gear ratio of a transmission (103) coupled to the engine. [7] The vehicle control device according to claim 1, wherein the deceleration level control unit (407) controls the deceleration level of the vehicle (100) such that the deceleration level becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level by controlling an engagement degree of the power transmission mechanism. [8] The vehicle control device according to claim 1, wherein the deceleration level control unit (407) controls the deceleration level of the vehicle (100) such that the deceleration level becomes the target deceleration level calculated from the first target deceleration level and the second target deceleration level by controlling an engagement degree of the power transmission mechanism such that the engagement degree of the power transmission mechanism is increased when the deceleration request is large, whereas the engagement degree of the power transmission mechanism is decreased when the deceleration request is small. [9] A vehicle control device according to claim 1, wherein fuel injection into the engine is started when a restart request is generated by an operation of the brake pedal (117).

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