JP2015218657A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device for enabling the automatic stop and restart of an engine, which reflect the will of a driver.SOLUTION: A vehicle control device is characterized by comprising: engine automatic stop means (an economic run ECU) for stopping an engine automatically under a predetermined stop condition; and differential lock means (or a differential mechanism) enabled to perform a differential lock function by the operation of a driver. The vehicle control device is characterized by inhibiting said automatic stop of the engine while the differential lock by said differential lock means is being actuated.

Description

  The present invention relates to a vehicle control device.

  While environmental issues are attracting attention, the engine is temporarily stopped when the vehicle is stopped, and the engine is started when the vehicle starts running, with the aim of suppressing energy consumption and noise when the vehicle is stopped (waiting for a signal, etc.) A so-called idling stop function (control) that performs vehicle control is attracting attention.

  In addition, vehicles having a diff lock function are known in order to assist traveling in places with poor road surface conditions such as rocky places, snowy roads, and frozen roads. For example, in places where road surfaces such as rocky places are not maintained, when a wheel climbs a step, one wheel may float, and driving torque may not be transmitted to the wheel, making it impossible to travel. In such a case, the diff lock function is activated and all the wheels are rotated at the same rotational speed, thereby enabling traveling in places with poor road surface conditions such as rocky places.

  However, when this differential lock function is applied to a vehicle having an idling stop function, the following problems may occur.

  For example, when the diff lock function is activated and the vehicle travels on a rocky terrain, usually the vehicle is repeatedly stopped and started in order to get over the level difference. In such a case, it is very troublesome for the driver to repeat the automatic stop and restart of the engine each time. In addition, if the engine stops at the time of overcoming the step, there is a concern that the driving torque is reduced, the vehicle slips, and the behavior of the vehicle becomes unstable.

  On the other hand, there is a known technology that prohibits the engine from being stopped by idling stop control when the vehicle travels on a road surface that is not well maintained such as a rocky place or a slippery road surface such as a snowy road or a frozen road. (For example, refer to Patent Documents 1 and 2). Patent Document 1 determines whether or not to automatically stop and restart an engine in idling stop control by detecting a road surface state. Patent Document 2 determines whether or not to automatically stop and restart the engine in the idling stop control by detecting the slip region of the wheel based on the steering angle of the vehicle and the traveling speed of the vehicle. . This realizes automatic engine stop and restart in consideration of road surface deterioration.

JP 2003-035177 A JP 2010-285961 A

  However, in the vehicles disclosed in Patent Documents 1 and 2, automatic stop and restart of the engine are automatically prohibited when a certain road surface condition is satisfied. Depending on the degree of road surface condition and the travel route of the vehicle, it may be preferable not to prohibit the automatic stop and restart of the engine. According to the functions disclosed in Patent Documents 1 and 2, automatic stop and restart of the engine are uniformly prohibited in a predetermined road surface state regardless of the driver's intention.

  Therefore, an object of the present disclosure is to provide a vehicle control device capable of automatically stopping and restarting an engine reflecting the driver's intention.

  In one aspect of the present disclosure, an automatic engine stop unit that automatically stops the engine under a predetermined stop condition, and a differential lock unit that enables a differential lock function to be operated by a driver's operation, the automatic engine stop unit includes: Provided is a vehicle control device that prohibits the automatic stop of the engine during operation of a differential lock function by a differential lock means.

  According to the present disclosure, it is possible to provide a vehicle control device that enables automatic stop and restart of an engine reflecting the driver's intention.

It is explanatory drawing explaining the vehicle provided with the control apparatus which concerns on one Embodiment. It is a flowchart which shows an example of the processing operation of the control apparatus which concerns on one Embodiment. It is a flowchart which shows another example of the processing operation of the control apparatus which concerns on one Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.
(Configuration of vehicle 1)
FIG. 1 shows an example of the configuration of a vehicle 1 equipped with a control device 100 according to an embodiment.

  As shown in FIG. 1, a vehicle 1 on which a control device 100 according to this embodiment is mounted includes a vehicle body 10, front wheels 20FR and 20FL, rear wheels 20RR and 20RL, an engine 31 as a power source, and a transmission 32. And diff lock means. The differential lock means includes a differential lock mechanism 35 and a differential lock switch 42.

  A transmission 32 is connected to the engine 31, and a propeller shaft 33 is connected to the transmission 32. The transmission 32 is a transmission that transmits the driving force generated in the engine 31 and changes the gear ratio in accordance with the traveling state of the vehicle 1 and the like. The transmission 32 travels based on a control signal from the ECU 100 described later. An optimum shift shift is configured. A drive shaft (drive shaft) 21 </ b> R is connected to the propeller shaft 33 via a differential mechanism 35. Rear wheels 20RR and 20RL are connected to the drive shaft 21R, and a shaft 21F is connected to the front wheels 20FR and 20FL.

  The rotation of the crankshaft (not shown) of the engine 31 is transmitted to the differential mechanism 35 via the transmission 32. The differential mechanism 35 distributes the driving force transmitted to the propeller shaft 33. The rotation distributed to the left and right by the differential mechanism 35 is transmitted to the left and right rear wheels 20RR and 20RL by the drive shaft 21R.

  The engine 31 is constituted by, for example, a 4-cycle in-line four-cylinder gasoline engine. The engine 31 may be configured by various types of engines such as an in-line 6-cylinder engine and a V-type 6-cylinder engine.

The vehicle 1 also includes an electronic control unit (hereinafter referred to as “ECU”) 100 as a control device for controlling the vehicle 1.
(Control mechanism of control device 100)
The ECU 100 includes an engine electronic control unit (hereinafter referred to as “engine ECU”) 111, an eco-run electronic control unit (hereinafter referred to as “eco-run ECU”) 112, and an ABS (anti-skid brake system) electronic control unit (hereinafter referred to as “brake”). ECU ”) 113 and a vehicle state detection ECU 114. The engine ECU 111, the eco-run ECU 112, the brake ECU, and the vehicle state detection ECU 114 are connected to each other via a communication standard such as CAN (Controller Area Network).

  The engine ECU 111 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and performs processing such as calculation based on various input signals. And outputs various signals to the engine 31 and the eco-run ECU 112.

  More specifically, in order to determine the automatic stop condition and restart condition of the engine 31, the engine ECU 111 has an accelerator switch (not shown) to turn on / off the accelerator and an accelerator opening sensor (not shown). Detection signals relating to an accelerator opening, a shift position by a shift position sensor (not shown), an engine speed by a rotation speed sensor (not shown), and the like are input.

  Similar to the engine ECU 111, the eco-run ECU 112 includes a CPU, a ROM, and a RAM. The eco-run ECU 112 includes an engine stop command signal for stopping the engine 31 and an engine restart signal for restarting the engine 31. A start command signal is output. As a result, the engine ECU 111 outputs control signals such as fuel injection, intake air, and ignition control to the engine 31. The eco-run ECU 112 outputs a restart starter control signal to the tandem starter motor 53 when the engine 31 is restarted. The eco-run ECU 112 receives status signals indicating statuses such as a fuel injection state, an intake air amount state, and an ignition state output from the engine ECU 111.

  As described above, the eco-run ECU 112 has a function as an engine automatic stop unit that automatically stops the engine under a predetermined stop condition, and also has a function as an engine restart unit that restarts the engine under a predetermined restart condition. . Here, the stop condition refers to, for example, a case where the driver operates the brake pedal and the vehicle speed is zero or a predetermined value or less. The restart condition refers to, for example, that the driver releases the brake pedal, the shift lever is operated to the drive range (D), the accelerator pedal is operated, and the like.

  Like the engine ECU 111, the brake ECU 113 includes a CPU, a ROM, and a RAM, and includes a brake master pressure by a brake master pressure sensor, a vehicle speed by a vehicle speed sensor (not shown), a booster cylinder pressure by a brake boost pressure sensor. Etc. are input.

  The brake ECU 113 detects the rotation amount of the wheel per unit time using a vehicle speed sensor provided for each wheel, detects the vehicle speed of the vehicle 1 based on the rotation amount of each wheel, and rotates the wheel of each wheel. The braking of the vehicle 1 is controlled based on the amount and the vehicle speed. A signal indicating the vehicle speed of the vehicle 1 detected by the brake ECU 113 is input to the eco-run ECU 112 via a communication standard such as CAN.

  The vehicle state detection ECU 114 includes a CPU, a ROM, and a RAM, like the engine ECU 111, and a detection signal related to the gravitational acceleration of the vehicle 1 by the acceleration sensor 41 is input. Although not shown, a detection signal related to the yaw rate around the longitudinal axis of the vehicle 1 by the yaw rate sensor is also input to the vehicle state detection ECU 114. The yaw rate sensor detects a yaw rate when the vehicle 1 rotates horizontally with respect to the road surface, and detects accelerations in the front, rear, left and right of the vehicle 1.

  The vehicle state detection ECU 114 is an electronic control device that detects the state of the vehicle 1. In this embodiment, by detecting the magnitude and direction of gravitational acceleration using the acceleration sensor 41, the vehicle state detection ECU 114 calculates the frequency of the vehicle 1 and the vehicle body inclination angle (road surface gradient).

  The acceleration detection value detected by the acceleration sensor 41 or the like, the vehicle state calculated by the vehicle state detection ECU 114 (the gravitational acceleration of the vehicle 1, the vibration frequency of the vehicle 1, the inclination angle of the vehicle body, etc.) The road surface friction coefficient and the like are input to the eco-run ECU 112, respectively. Note that the vibration frequency of the vehicle 1, the inclination angle of the vehicle body, and the like may be calculated using a sensor other than the acceleration sensor 41 (for example, a horizontal sensor, an angle sensor, etc.). Here, the friction coefficient of the road surface is calculated by, for example, detecting a steering amount and a steering direction of a steering (not shown) by a magnetic resistance or the like by a steering sensor (not shown).

  Further, a differential lock switch 42 is electrically connected to the ECU 100. The differential lock switch 42 is an on / off switch for selecting the differential mechanism 35 to operate (lock) or non-operate (unlock).

  When the differential lock switch 42 is not operated, the differential mechanism 35 maintains the unlocked state, and when the differential lock switch 42 is operated, the differential mechanism 35 can be locked. Specifically, when the diff lock switch 42 is operated by the driver, an ON signal is transmitted from the diff lock switch 42 to the ECU 100, and the differential mechanism 35 becomes lockable.

When the differential mechanism 35 is unlocked, a rotational difference between the left and right rear wheels 20RR and 20RL is allowed. On the other hand, when the differential mechanism 35 is locked, there is no rotational difference between the left and right rear wheels 20RR and 20RL.
(Control operation of control device 100)
Next, the control operation of the control device 100 will be described with reference to FIG.

  The eco-run ECU 112 outputs an engine stop command signal for automatically stopping the engine and an engine restart command signal for restarting the engine to the engine ECU 111. As a result, the engine ECU 111 outputs control signals such as fuel injection, intake air, and ignition control to the engine 31. Further, the eco-run ECU 112 outputs a restart starter control signal to the tandem starter motor 53 when the engine 31 is restarted. Thus, the vehicle 1 according to the present embodiment has an idling stop function (control).

  The vehicle 1 further includes a diff lock function that can distribute the driving force transmitted from the transmission 32 to the left and right rear wheels 20RR and 20RL. The differential lock function can be locked by the differential mechanism 35. Specifically, the acceleration sensor 41 is electrically connected to the ECU 110, and based on the detection signal detected from the acceleration sensor 41, the vehicle state detection ECU 114 causes the gravitational acceleration of the vehicle 1, the vibration frequency of the vehicle 1, The inclination angle of the vehicle body is calculated. Based on detection signals from the vehicle speed sensor, steering sensor, etc., the brake ECU 113 calculates the friction coefficient of the road surface.

  The vehicle state (such as gravitational acceleration of the vehicle 1) and the road surface state (such as the friction coefficient of the road surface) calculated as described above are input to the eco-run ECU 112, and the vehicle state and the road surface state are determined. Then, the differential mechanism 35 is locked when the vehicle state and the road surface condition satisfy predetermined conditions and the diff lock switch 42 is operated by the driver.

  In the present embodiment, when the driver operates the differential lock switch 42, automatic stop and restart of the engine 31 in the idling stop control are prohibited regardless of whether or not the differential mechanism 35 is locked. That is, when the driver operates the differential lock switch 42, the differential mechanism 35 may be locked or not (unlocked), but regardless of whether the differential mechanism 35 is locked or not. When the diff lock switch 42 is operated by the driver, the automatic stop and restart of the engine 31 in the idling stop control are prohibited.

The prohibition of the automatic stop and restart of the engine 31 in the idling stop control is performed by a driver's intention display. The driver's operation of the diff lock switch 42 is an intention display prohibiting idling stop control.
(Control processing of control device 100)
Next, control processing of the control device 100 will be described with reference to FIG. FIG. 2 is a flowchart illustrating an example of a processing operation of the control device according to the embodiment.

  In the vehicle 1 having the idling stop function and the diff lock function, when the driver determines that the road surface is a bad road and operates the diff lock switch (SW) 42, an ON signal of the diff lock switch 42 is input to the ECU 100 (step S1) Yes), the eco-run ECU 112 prohibits the automatic stop and restart of the engine 31 in the idling stop control (step S2). In other words, in this case, the prohibition signal for prohibiting the idling stop control is output from the eco-run ECU 112 to the engine ECU 111 so that the engine stop command signal and the engine restart command signal are not transmitted. Regardless of whether or not the differential mechanism 35 is locked, the engine 31 is controlled not to perform idling stop control.

  On the other hand, when the driver is not operating the differential lock switch 42 (No in step S1), the eco-run ECU 112 permits automatic stop and restart of the engine 31 in the idling stop control (step S3). That is, in this case, an engine stop command signal and an engine restart command signal are transmitted from the eco-run ECU 112 to the engine ECU 111. The engine 31 is controlled so that idling stop control is performed. In this case, since the driver determines that the road surface is not a bad road, it is preferable to perform the idling stop control from the viewpoints of energy consumption and noise suppression.

  According to the present embodiment, it is possible to arbitrarily select permission / prohibition of automatic stop and restart of the engine 31 in idling stop control based on the driver's intention. As described above, when the driver determines the road surface state, the engine 31 can be automatically stopped and restarted in the idling stop control reflecting the driver's intention.

  Next, another example of the control process of the control device 100 will be described with reference to FIG. FIG. 3 is a flowchart illustrating another example of the processing operation of the control device according to the embodiment.

  FIG. 3 is a flowchart when the eco-run ECU 112 first determines the road surface condition and receives the determination result to determine whether or not the driver operates the diff lock switch 42.

  In the vehicle 1 having an idling stop function and a differential lock function, the eco-run ECU 112 in the ECU 100 determines the road surface state (step S11). When it is not determined that the road surface is uneven or not muddy and the road surface state is bad (the road surface is a bad road) (No in step S11), the road surface is returned to step S11 again. The loop process is repeated until the rough road condition is satisfied. Only when the rough road condition on the road surface is satisfied (Yes in step S11), the process proceeds to the next step S2.

  In step S11, when the eco-run ECU 112 determines that the road surface is a bad road, the driver determines whether to operate the diff lock switch (SW) 42 based on the determination result and the actual road surface state. (Step S12). As a result of determination by the eco-run ECU 112, for example, the operation item “bad road” is displayed on the display of the instrument panel. When the driver also determines that the road surface is a bad road and operates the differential lock switch 42 (Yes in step S12), the eco-run ECU 112 prohibits the automatic stop and restart of the engine 31 in the idling stop control (step S13). That is, in this case, the eco-run ECU 112 outputs a prohibition signal for prohibiting idling stop control to the engine ECU 111 so as not to transmit an engine stop command signal and an engine restart command signal. The engine 31 is controlled not to perform idling stop control. In this case, the differential mechanism 35 is locked.

  On the other hand, the eco-run ECU 112 determines that the road surface is a bad road, but if the driver determines that the road surface is not a bad road, the diff lock switch 42 is not operated (No in step S12). In this case, the eco-run ECU 112 permits automatic stop and restart of the engine 31 in the idling stop control (step S14). That is, in this case, the eco-run ECU 112 transmits an engine stop command signal and an engine restart command signal. The engine 31 is controlled so that idling stop control is performed. In this case, since the driver determines that the road surface is not a bad road, it is preferable to perform the idling stop control from the viewpoints of energy consumption and noise suppression. In this case, the differential mechanism 35 is unlocked.

  Accordingly, it is possible to arbitrarily select permission / prohibition of automatic stop and restart of the engine 31 in the idling stop control reflecting the driver's intention while considering the road surface determination by the eco-run ECU 112.

  Depending on the road surface condition, it may not be preferable to automatically stop and restart the engine in the idling stop control. In this case, the automatic stop and restart of the engine 31 in the idling stop control are prohibited by the driver's intention display. As a result, for example, when the vehicle 1 travels on a rocky place with ups and downs such as unevenness, the troublesomeness caused by repeated automatic stop and restart of the engine in the idling stop control can be suppressed every time the vehicle 1 gets over the step. . Moreover, it can reduce that the vehicle 1 slips on a bad road surface (bad road) and the behavior of the vehicle 1 becomes unstable.

  Since the vehicle control apparatus 100 according to the present embodiment is configured as described above, the automatic stop of the engine 31 can be prohibited during the operation of the differential lock function by the differential lock means. Here, the fact that the differential lock function by the differential lock means is operating means a state in which the differential lock switch 42 is operated by the driver.

  As described above, the control device 100 mounted on the vehicle 1 has been described with the embodiment. However, the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention.

  In the present embodiment, the control device 100 mounted on the two-wheel drive vehicle 1 has been exemplified and described, but the present invention is not limited to this configuration. The present invention can be realized even with a four-wheel drive vehicle. In this case, the front differential mechanism provided on the (front drive) shaft 21F connecting the front wheels 20FR and 20FL side and the (rear) differential mechanism provided on the (rear) drive shaft 21R connecting the rear wheels 20RR and 20RL side. 35, and a center differential mechanism provided between the front differential mechanism and the rear differential mechanism.

  The front differential mechanism is configured to absorb the rotational difference between the left and right front wheels 20FR and 20FL when the vehicle is turning. The rear differential mechanism is configured to absorb the rotational difference between the left and right rear wheels 20RR and 20RL when the vehicle is turning. The center differential mechanism is configured to absorb the rotational difference between the front wheels 20FR and 20FL and the rear wheels 20RR and 20RL when the vehicle is turning. For example, when the center differential mechanism is in the locked state, the front wheels and the rear wheels rotate at the same rotational speed, and the driving force is transmitted to the rear wheels 20RR and 20RL even when the front wheels 20FR and 20FL are idling. The vehicle 1 can be easily traveled even on a rocky surface with a rough surface, a muddy road surface, a snowy road, and the like. Also in this case, it is possible to arbitrarily select permission / prohibition of automatic stop and restart of the engine 31 in the idling stop control reflecting the driver's intention by operating the differential lock switch.

DESCRIPTION OF SYMBOLS 1 Vehicle 41 Acceleration sensor 42 Differential lock switch 100 Control apparatus 111 Engine ECU
112 Eco-run ECU
113 Brake ECU
114 Vehicle state detection ECU

Claims (1)

Engine automatic stop means for automatically stopping the engine under a predetermined stop condition;
Diff lock means that enables the diff lock function to be operated by a driver's operation, and
The engine automatic stop means prohibits the automatic stop of the engine during the operation of the differential lock function by the differential lock means.

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