JP2014185557A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a vehicle which can prevent an unnecessary start and a stop of an engine, and can quickly start the engine when the start of the engine is required.SOLUTION: Since a prescribed angle θ1 becomes large when a vehicle speed V becomes high during a stop of an engine 12, a steering angle θ does not reach the prescribed angle θ1 even if a steering wheel 67 is disconnected during curve traveling, and the engine 12 is not restarted. Therefore, an automatic start of the engine 12 is prevented during the curve traveling, and the lowering of the assist torque of the steering wheel 67 resulting from a drop of a voltage accompanied by the engine automatic start can be prevented. Accordingly, a catch caused by the lowering of the assist torque is eliminated, and a driver can be prevented from being imparted with an uncomfortable feeling.

Description

  The present invention relates to a vehicle control device, and more particularly to control of a vehicle that can automatically stop and automatically start an engine while the vehicle is running.

  A vehicle (so-called idle stop vehicle) is known in which an engine is automatically stopped based on a predetermined automatic stop condition while the vehicle is stopped, and an engine is automatically started based on a predetermined automatic start condition. The vehicle of patent document 1 is also an example. The vehicle of Patent Document 1 includes the steering angle of the steering as an automatic starting condition of the vehicle. When the steering angle or the steering angular velocity of the steering exceeds a predetermined value, the engine is automatically started at an intersection or the like. It is possible to start quickly.

JP 2011-12552 A

  By the way, not only when the vehicle is stopped but also when the vehicle is running, an engine that automatically stops and starts the engine has been proposed. In such a vehicle that automatically stops and starts the engine while the vehicle is running, the steering angle, steering angular velocity, and steering torque of the steering wheel exceed the predetermined angle, the predetermined angular velocity, and the predetermined torque while the vehicle is running with the engine stopped. When the engine automatically starts, the engine automatically starts when the steering angle, the steering angular velocity, and the steering torque increase during curve driving. The starter motor is driven when starting the engine during curve traveling. However, since the starter motor consumes a large amount of power, the voltage of the battery greatly decreases at that time. Accordingly, malfunctions may occur in the electrical equipment, which may cause the driver to feel uncomfortable. In particular, when so-called electric power steering is adopted, in which steering torque is reduced by generating assist torque by the motor during steering, the assist torque of the electric power steering is caused by the voltage drop of the battery due to the starter motor drive. May be reduced (changed), and at this time, a catch may occur, which may cause the driver to feel uncomfortable.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle control device that can prevent a driver from feeling uncomfortable during steering.

  In order to achieve the above object, the subject matter of the first invention is (a) automatic stop control for automatically stopping the engine based on a predetermined automatic stop condition, and the steering angle of the steering is equal to or greater than a predetermined angle. Automatic start control for restarting the engine based on an automatic start condition including at least one of the steering angular velocity of the steering being equal to or higher than a predetermined angular velocity and the steering torque of the steering being equal to or higher than a predetermined torque. (B) when the vehicle speed during the automatic stop of the engine is high, the predetermined angle, the predetermined angular speed, and the predetermined torque when the vehicle speed during the automatic stop is high compared to when the vehicle speed during the automatic stop is low It is characterized by increasing at least one of the above.

  In this way, when the vehicle speed increases while the engine is stopped, at least one of the predetermined angle, the predetermined angular velocity, and the predetermined torque increases, so that the steering angle does not reach the predetermined angle even if the steering is turned off during curve driving. The steering angular velocity does not reach the predetermined angular velocity, and the engine does not restart because the steering torque does not reach the predetermined torque. Accordingly, there is no voltage drop caused by driving the starter motor when the engine is started, so that it is possible to eliminate a sense of incongruity due to malfunction of the electrical equipment due to the voltage drop. For example, in the case of providing a configuration that reduces the steering force by generating an assist torque by a motor during steering, there is no decrease in the assist torque due to a voltage drop, and there is no catching that occurs during steering. Can prevent a sense of incongruity.

  Preferably, when the vehicle speed during automatic stop of the engine is a positive value, at least one of the predetermined angle, the predetermined angular speed, and the predetermined torque is greater than when the vehicle speed during automatic stop is zero. Enlarge. In this way, during the forward traveling of the vehicle, the predetermined angle, the predetermined angular velocity, and the predetermined torque of the steering, which are the automatic engine starting conditions, increase, so that the automatic starting of the engine is prevented during the curve traveling. Therefore, there is no voltage drop due to engine start during curve running, and it is possible to eliminate the uncomfortable feeling due to the malfunction of the electrical equipment due to the voltage drop. In particular, when a configuration is adopted in which assist torque is generated by a motor during steering to reduce steering steering force, there is no decrease in assist torque due to voltage drop, and there is no catching that occurs during steering. It is possible to prevent discomfort given to the person.

  Preferably, when the vehicle speed during the automatic stop of the engine is a positive value, the engine is not automatically started. In this way, when the vehicle speed is a positive value, the engine is not automatically started. Therefore, since the voltage drop accompanying the engine start is eliminated, it is possible to eliminate the uncomfortable feeling caused by the malfunction of the electric equipment due to the voltage drop. In particular, when a configuration is adopted in which assist torque is generated by a motor during steering to reduce steering steering force, there is no decrease in assist torque due to voltage drop, and there is no catching that occurs during steering. It is possible to prevent discomfort given to the person.

It is the schematic block diagram which showed the principal part of the control system together with the skeleton of the vehicle drive device which is a part of the vehicle to which this invention is applied suitably. In the main part of the control operation of the electronic control unit, that is, in a vehicle in which the engine is automatically stopped and started even during traveling, the assist torque during steering is prevented by preventing the engine from automatically starting during curve traveling. It is a flowchart explaining the control action which prevents a change.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a schematic configuration diagram showing a main part of a control system together with a skeleton diagram of a vehicle drive device 10 which is a part of a vehicle 8 to which the present invention is preferably applied. The vehicle drive device 10 includes an engine 12 that is an internal combustion engine such as a gasoline engine or a diesel engine that generates power by combustion of fuel as a driving force source, and the output of the engine 12 is differential from the automatic transmission 16. It is transmitted to the left and right wheels 20 via the gear unit 18. A power transmission device such as a damper device or a torque converter is provided between the engine 12 and the automatic transmission 16, but a motor generator that functions as a driving force source may be provided.

  The engine 12 includes an engine control device 30 having various devices necessary for output control of the engine 12, such as an electronic throttle valve, a fuel injection device, and a starter motor. The electronic throttle valve controls the amount of intake air, and the fuel injection device controls the amount of fuel supplied. Basically, the amount of operation of the accelerator pedal (accelerator opening) that is the driver's required output It is controlled according to Acc. The fuel injection device 30 can stop the fuel supply (fuel cut F / C) even when the vehicle is traveling, for example, when the accelerator opening Acc is zero and the accelerator is OFF. When the engine 12 is stopped and receives a command to start the engine 12, the starter motor rotates the engine to a rotation speed at which the engine 12 can operate independently, restarts the fuel supply, and starts the engine 12.

  The automatic transmission 16 is a stepped automatic transmission such as a planetary gear type in which a plurality of gear stages having different gear ratios γ are established depending on the disengagement states of a plurality of hydraulic friction engagement devices (clutch and brake). The shift control is performed by an electromagnetic hydraulic control valve, a switching valve or the like provided in the hydraulic control device 32. The clutch C <b> 1 functions as an input clutch of the automatic transmission 16, and is similarly engaged and released by the hydraulic control device 32. The clutch C1 corresponds to an interrupting device (clutch) that connects and disconnects the power transmission path between the engine 12 and the wheel 20, that is, interrupts the power transmission path. Further, as the automatic transmission 16, a continuously variable transmission such as a belt type may be used instead of the stepped transmission.

  In the vehicle 8 according to the present embodiment, a so-called electric power steering system is employed in which an assist torque is generated during steering by a motor 34 attached to a steering column or a reduction mechanism (not shown) to reduce the steering force of the steering 67. ing.

  The vehicle drive device 10 configured as described above includes an electronic control device 50. The electronic control unit 50 includes a so-called microcomputer having a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. Do. A signal representing the brake operation force Brk corresponding to the operation force of the brake pedal is supplied from the brake operation amount sensor 60 to the electronic control unit 50, and the accelerator opening degree Acc that is the depression amount of the accelerator pedal is supplied from the accelerator opening degree sensor 62. A signal indicating the rotation speed (engine rotation speed) Ne of the engine 12 is supplied from the engine rotation speed sensor 64, and the rotation speed Nout of the output shaft of the automatic transmission 16 corresponding to the vehicle speed V is supplied from the vehicle speed sensor 66. A signal indicating (output shaft rotation speed Nout) is supplied, a signal indicating the steering angle θ of the steering wheel 67 is supplied from the steering angle sensor 68, and a signal indicating the steering torque N of the steering wheel 67 is supplied from the steering torque sensor 69. A signal representing the engine water temperature Tw is supplied from the engine water temperature sensor 70. In addition, various types of information necessary for various types of control are supplied.

  The electronic control device 50 is configured to functionally include an engine start / stop control unit 78, an engine stop determination unit 80, a steering determination unit 82, and a travel determination unit 84.

  The engine start / stop control unit 78 executes automatic stop control for automatically stopping the engine 12 based on a predetermined automatic stop condition, and restarts the engine 8 based on the predetermined automatic start condition when the engine is stopped. The automatic start control is executed. Note that the automatic stop control and the automatic start control of the engine 12 are not different from the conventional engine stop control and engine start control, and thus the description thereof is omitted.

  The engine start / stop control unit 78 determines the automatic stop of the engine 12 based on parameters such as the accelerator opening Acc, the brake operation force Brk, and the vehicle speed V, for example. For example, the engine start / stop control unit 78 cancels the depression of the accelerator pedal (accelerator opening Acc is zero), the brake operating force Brk of the brake pedal is equal to or higher than the predetermined value Brk1, and the vehicle speed V is lower than the predetermined value V1. Is determined, it is determined that the automatic stop condition of the engine 12 is satisfied, and automatic stop control for automatically stopping the engine 12 is executed. Each of the conditions relating to the accelerator opening Acc, the brake operation force Brk, and the vehicle speed V corresponds to the predetermined automatic stop condition of the present invention. Moreover, this automatic stop condition is an example and may be changed as appropriate.

  The engine start / stop control unit 78 performs automatic start control for restarting the engine 12 based on predetermined automatic start conditions while the engine 12 is stopped. When the engine start / stop control unit 78 determines restart of the engine 12 based on the automatic start condition of the engine 12 including the steering angle θ, the steering angular velocity ω, and the steering torque N of the steering 67, the automatic start control (engine 12 restart). For example, the engine start / stop control unit 78 restarts the engine 12 when the steering angle θ of the steering 67 becomes equal to or larger than a predetermined angle θ1 set in advance. Further, the engine start / stop control unit 78 sequentially calculates the steering angular acceleration ω of the steering 67, and restarts the engine 12 when the steering angular acceleration ω becomes equal to or higher than a predetermined angular velocity ω1 set in advance. The engine start / stop control unit 78 sequentially detects the steering torque N of the driver with a torque sensor or the like, and restarts the engine 12 when the steering torque N becomes equal to or higher than a predetermined torque N1 set in advance. Thus, when the start condition of the engine 12 is set, for example, when a quick start of the vehicle 8 is requested in an intersection or the like, the driver turns the steering wheel 67 so that the steering angle θ is equal to or larger than a predetermined angle θ1 (steering angular velocity). ω becomes a predetermined angular velocity ω1 or more and steering torque N becomes a predetermined torque N1 or more), and the engine 12 restarts quickly. Therefore, the engine 12 is restarted quickly, and the vehicle 8 can be started quickly.

  However, when the engine 12 is restarted based on the steering angle θ of the steering 67 being equal to or greater than the predetermined value θ1, the following problem occurs. For example, when the steering angle θ of the steering 67 becomes equal to or larger than a predetermined angle θ1 while traveling on a curve with the engine 12 stopped, the engine 12 is restarted. At the time of starting the engine, the engine rotation speed Ne is increased by the starter motor. However, when the starter motor is driven, a large amount of power is consumed, and the voltage of the battery is greatly reduced at that moment. Electric power is also supplied from the same battery to the motor 34 that generates assist torque when the steering 67 is steered, and the assist torque decreases due to this voltage drop. Therefore, a catch may occur at the moment when the assist torque decreases during steering, which may cause the driver to feel uncomfortable. In addition, since the engine 12 is automatically started during curve driving, a change in driving force may occur, which may give the driver a sense of discomfort.

  Therefore, the engine start / stop control unit 78 changes the predetermined angle θ1 according to the vehicle speed V during the automatic stop of the engine 12 when the engine 12 is restarted when the steering angle θ becomes equal to or larger than the predetermined angle θ1. Specifically, when the vehicle speed V during automatic engine stop is high, the predetermined angle θ1 is made larger than when the vehicle speed V during automatic stop is low. Here, preferably, when the vehicle 8 is traveling forward, that is, when the vehicle speed V is a positive value, the predetermined angle θ1 is made larger than when the vehicle speed V is zero. More preferably, when the vehicle speed V is a positive value, the predetermined angle θ1 is set to a sufficiently large value so that the engine 12 is not restarted.

  As described above, when the vehicle speed V is a positive value, when the predetermined angle θ1 is increased compared to when the vehicle speed V is zero, for example, the steering angle θ does not exceed the predetermined angle θ1 during curve traveling. Restart is not determined. Accordingly, since the engine 12 is not automatically started during the curve running, the starter motor is not driven to start the engine, and the voltage drop due to the starter motor drive is eliminated. Therefore, the assist during the steering caused by the voltage drop is eliminated. The catch by the torque fall is also avoided. In addition, since a change in driving force due to engine start during steering is also prevented, a sense of incongruity that occurs during steering can be avoided. Further, when the vehicle speed V is zero, the predetermined angle θ1 is small, so that when the steering 67 is turned off, the engine 12 can be started quickly and the vehicle 8 can be started quickly. The predetermined angle θ1 is set to a large value so that the engine 12 is not automatically started when the vehicle speed V is a positive value. On the other hand, when the vehicle is stopped, that is, when the vehicle speed V is zero, the predetermined angle θ1 is set to such a low value that the vehicle 8 starts quickly when the steering 67 is turned off at an intersection, for example.

  The same control is executed for the steering angular acceleration ω and the steering torque N. For example, the engine start / stop control unit 78 changes the value of the predetermined angular velocity ω1 according to the vehicle speed V when the engine 12 is automatically started when the steering angular acceleration ω is equal to or greater than the predetermined angular acceleration ω1. Specifically, when the vehicle speed V during steering is high, the predetermined angular velocity ω1 is made larger than when the vehicle speed V is low. Preferably, when the vehicle speed V is a positive value, the predetermined angular velocity ω1 is made larger than when the vehicle speed V is zero. More preferably, when the vehicle speed V is a positive value, the predetermined angular velocity ω1 is set to a sufficiently large value so that the engine 12 is not automatically started. Further, the engine start / stop control unit 78 changes the value of the predetermined torque N1 according to the vehicle speed V when the engine 12 is automatically started when the steering torque N becomes equal to or greater than the predetermined torque N1. Specifically, when the vehicle speed V during steering is high, the predetermined torque N1 is increased compared to when the vehicle speed V is low. Preferably, when the vehicle speed V is a positive value, the predetermined torque N1 is made larger than when the vehicle speed V is zero. More preferably, when the vehicle speed V is a positive value, the predetermined torque N1 is set to a sufficient value so that the engine 12 is not automatically started. As described above, even when the predetermined angular velocity ω1 and the predetermined torque N1 are changed according to the vehicle speed V, the engine 12 is not automatically started during the curve traveling, so that the voltage drop due to the starter motor drive is eliminated, and the steering is performed. The trap by the fall of the assist torque inside is also avoided.

  Returning to FIG. 1, the engine stop determination unit 80 determines whether or not the engine 12 is stopped. The engine stop determination unit 80 determines stop of the engine 12 based on, for example, a stop signal (fuel cut signal) of the engine 12 output to the engine control device 30, an engine rotation speed Ne, or the like.

  The steering determination unit 82 determines whether or not the steering 67 has been steered. The steering determination unit 82 determines whether or not the steering 67 is steered based on whether or not the steering angle θ detected by the steering angle sensor 68 is equal to or larger than a predetermined angle θ1. Further, the steering determination unit 82 determines the presence or absence of the steering 67 based on whether or not the steering angular velocity ω of the steering 67 calculated sequentially is equal to or higher than a predetermined angular velocity ω1 set in advance. The steering determination unit 82 determines the presence or absence of the steering 67 based on whether or not the steering torque N detected by the steering torque sensor 69 is equal to or greater than a predetermined torque N1 that is set in advance. The predetermined value θ1, the predetermined angular velocity ω1, and the predetermined torque N1 are changed based on the vehicle speed V as described above. For example, when the vehicle speed V is a positive value, steering of the steering 67 is denied. Set to a large value.

  When it is determined that the steering 67 has been steered, the travel determination unit 84 is executed. The traveling determination unit 84 determines whether or not the vehicle 8 is in a traveling state. Specifically, the traveling determination unit 84 detects the vehicle speed V, and the vehicle 8 is in a traveling state if the detected vehicle speed V is equal to or greater than a preset positive value threshold value greater than zero. Is determined.

  If it is determined that the steering 67 is not steered, the engine start / stop control unit 78 continues to stop the engine 12. Even if it is determined that the steering 67 is being steered, if it is determined that the vehicle 8 is in a traveling state, the engine start / stop control unit 78 continues to stop the engine 12. Thus, for example, the automatic start of the engine 12 is avoided during curve driving, so that the assist torque of the steering 67 due to the starter motor drive is not reduced, and the catching during steering is also avoided. On the other hand, when it is determined that the steering 67 is being steered and the vehicle 8 is in a stopped state, the engine start / stop control unit 78 restarts the engine 12. As a result, the engine 12 is started quickly when the steering wheel 67 is turned off at an intersection or the like, so that the vehicle can be started quickly.

  FIG. 2 shows an important part of the control operation of the electronic control unit 50, that is, an unnecessary start and stop of the engine 12 in a vehicle in which the automatic stop and automatic start of the engine 12 are executed even during traveling. 12 is a flowchart for explaining a control operation that enables quick engine start when 12 start is required, and is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds.

  First, in step S1 (hereinafter, step is omitted) corresponding to the engine stop determination unit 80, it is determined whether or not the engine 12 is in a stopped state. If S1 is negative, the routine is terminated. When S1 is affirmed, in S2 corresponding to the engine start / stop control unit 78 and the steering determination unit 82, whether or not the steering angle θ of the steering 67 is equal to or larger than the predetermined angle θ1, whether the steering angular velocity ω of the steering 67 is the predetermined angular acceleration ω1. Whether or not the steering 67 has been steered is determined based on whether or not the steering torque N of the steering 67 is equal to or greater than a predetermined torque N1. Here, the predetermined angle θ1, the predetermined angular velocity ω1, and the predetermined torque N1 are changed according to the vehicle speed V, and are set to larger values when the vehicle speed V is a positive value than when the vehicle speed V is zero. . When S2 is denied, the stop of the engine 12 is continued in S4 corresponding to the engine start / stop control unit 78. When S2 is affirmed, it is determined in S3 corresponding to the traveling determination unit 84 whether or not the vehicle 8 is in a traveling state. When S3 is affirmed, the engine 12 is continuously stopped in S4. On the other hand, if S3 is negative, the engine 12 is restarted in S5 corresponding to the engine start / stop control unit 78. Therefore, for example, since the engine 12 is started only by slightly turning the steering 67 at the intersection, the vehicle 8 can be started quickly.

  As described above, according to this embodiment, when the vehicle speed V increases while the engine 12 is stopped, the predetermined angle θ1, the predetermined angular velocity ω1, and the predetermined torque N1 increase, so that the steering 67 is turned off during curve driving. However, the steering angle θ does not reach the predetermined angle θ1, the predetermined angular velocity ω does not reach the predetermined angular velocity ω1, and the steering torque N does not reach the predetermined torque N1, so the engine 12 does not restart. Accordingly, since the voltage drop due to the automatic start of the engine 12 is eliminated while the vehicle is running on a curve, the assist torque of the steering 67 caused by the voltage drop is prevented from being reduced, so that a trap generated during the steering is eliminated and the driver feels uncomfortable. Can be prevented. In addition, since a change in driving force due to engine start during curve driving is prevented, a sense of incongruity given to the driver can be prevented. Further, when a quick start is required from a vehicle stop state such as an intersection, the engine 12 is automatically operated even if the steering 67 is turned down because the predetermined angle θ1, the predetermined angular velocity ω1, and the predetermined torque N1 are small. Since the vehicle is started, the vehicle is not sluggish and the driver is not uncomfortable.

  Further, according to the present embodiment, during the forward traveling of the vehicle 8, the predetermined angle θ1, the predetermined angular velocity ω1, and the predetermined torque N1 of the steering 67, which are automatic start conditions of the engine 12, increase, so that the steering angle θ is predetermined. The angle θ1 exceeds, the steering angular velocity ω exceeds the predetermined angular velocity ω1, the steering torque N does not exceed the predetermined torque N1, and as a result, the automatic start of the engine 12 during the curve traveling is avoided. Thus, by preventing a voltage drop caused by engine starting, a decrease in assist torque during steering can be prevented, and catching during steering can be avoided. In addition, while the vehicle is stopped, the engine 12 is automatically started quickly even if the steering 67 is turned small, so that, for example, the vehicle starts at the intersection.

  Further, according to the present embodiment, when the vehicle speed V is a positive value, the engine 12 is not automatically started. For example, during a curve run, the engine 12 is prevented from being automatically started, and the voltage drop due to engine start is reduced. It is possible to prevent the assist torque from being lowered during steering.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the automatic start of the engine 12 is determined based on the steering angle θ, the steering angular velocity ω, and the steering torque N of the steering 67, but it is not always necessary to determine based on all of these. It does not matter as long as it includes at least one of these.

  In the above-described embodiment, when the vehicle speed V is a positive value, the predetermined angle θ1 of the steering angle θ that determines whether the steering 67 is steered is set to a uniformly large value. It may be changed as appropriate, for example, the predetermined angle θ1 increases in proportion to the increase.

  Further, in the above-described embodiment, the control mode of restarting the engine 12 based on the steering angle θ is shown. However, in determining the engine restart, the engine start determination based on the accelerator opening Acc is actually used. This determination is also executed.

  In the above-described embodiment, the automatic stop of the engine 12 is determined based on the accelerator opening Acc, the brake operation force Brk, and the vehicle speed V. However, the automatic stop condition of the engine 12 is an example and can be changed as appropriate. It doesn't matter.

  In addition, the specific configuration of the vehicle 8 of the above-described embodiment is an example, and may be changed as appropriate.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

8: Vehicle 12: Engine 50: Electronic control device (control device)
67: Steering

Claims (3)

Based on a predetermined automatic stop condition, automatic stop control for automatically stopping the engine, at least a steering angle of the steering is not less than a predetermined angle, a steering angular speed of the steering is not less than a predetermined angular speed, and steering of the steering An automatic start control for restarting the engine based on an automatic start condition including at least one of the torque being equal to or greater than a predetermined torque,
When the vehicle speed during the automatic stop of the engine is high, at least one of the predetermined angle, the predetermined angular speed, and the predetermined torque is increased as compared with a case where the vehicle speed during the automatic stop is low. Control device.   When the vehicle speed during the automatic stop of the engine is a positive value, at least one of the predetermined angle, the predetermined angular speed, and the predetermined torque is made larger than when the vehicle speed during the automatic stop is zero. The vehicle control device according to claim 1.   3. The vehicle control device according to claim 2, wherein the engine is not automatically started when the vehicle speed during the automatic stop of the engine is a positive value.

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