WO2015190539A1

WO2015190539A1 - Vehicle control apparatus

Info

Publication number: WO2015190539A1
Application number: PCT/JP2015/066798
Authority: WO
Inventors: Kenichi Ishii; Takashi Kondo; Hiroto Miura; Hidehiko Miyoshi
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2014-06-11
Filing date: 2015-06-04
Publication date: 2015-12-17
Also published as: JP2016000977A

Abstract

A vehicle control apparatus is provided that can maintain an automatic engine stop function when an abnormality occurs in a parking support control function. The vehicle control apparatus includes a first control unit configured to include a parking support control function, and to output a prohibition request to an automatic engine stop function; and a second control unit configured to include the automatic engine stop function, and to maintain the automatic engine stop function, contrary to the prohibition request output from the first control unit, when an abnormality occurs in the parking support control function.

Description

[Title of the Invention] VEHICLE CONTROL APPARATUS

[Technical Field]

The disclosures herein generally relate to a vehicle control apparatus.

[Background Art]

A vehicle control apparatus has been known that does not automatically stop an internal combustion engine while a parking support device performs parking support (see, for example, Patent Document 1) .

[Related-Art Documents]

[Patent Documents]

[Patent Document 1] Japanese Laid-open Patent Publication NO. 2012-107580

[Summary of the Invention]

[Problem to be Solved by Invention]

Incidentally, while an abnormality occurs in a parking support function, if a control apparatus relating to the parking support function outputs a prohibition request to an automatic engine stop function, the automatic engine stop function may be unnecessarily disturbed.

It is an object of the present invention to provide a vehicle control apparatus that can maintain the automatic engine stop function when an abnormality occurs in a parking support function.

[Means to Solve the Problem]

According to at least one embodiment of the present invention, a vehicle control apparatus includes a first control unit configured to include a parking support control function, and to output a prohibition request to an automatic engine stop function; and a second control unit configured to include the automatic engine stop function, and to maintain the automatic engine stop function, contrary to the prohibition request output from the first control unit, when an abnormality occurs in the parking support control function.

[Advantage of the Invention]

According to at least one embodiment of the present invention, a vehicle control apparatus can be obtained that can maintain the automatic engine stop function when an abnormality occurs in such a parking support function.

[Brief Description of Drawings]

FIG. 1 is a diagram illustrating a basic configuration example of a vehicle control apparatus 1;

FIG. 2 is a flowchart illustrating an example of an S&S prohibition request generation process executed by a first ECU 10;

FIG. 3 is a flowchart illustrating an example of a mask flag setting process executed by a second ECU 20;

FIG. 4 is a flowchart illustrating an example of an operational method of an automatic engine stop function when receiving an S&S prohibition request from the first ECU 10; and

FIG. 5 is a flowchart illustrating an example of an operational method of an automatic engine stop function when not receiving an S&S prohibition request from the first ECU 10. [Mode for Carrying Out the Invention]

In the following, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram illustrating a basic configuration example of a vehicle control apparatus 1. The vehicle control apparatus 1 is built in a vehicle .

The vehicle control apparatus 1 includes a first ECU (Electronic Control Unit) 10, a second ECU 20, and a brake ECU 30. The first ECU 10, the second ECU 20 and the brake ECU 30 are connected with each other via an appropriate bus, for example, a CAN (controller area network) .

The first ECU 10 includes a parking support control function. The parking support control function may be an arbitrary one, for example, an IPA (Intelligent Parking Assist) or the like. The parking support control function may be a function that supports traveling backward to a parking target position, and/or, a function that supports traveling forward to a parking start position, or traveling forward when leaving a garage.

The first ECU 10 is connected with a parking switch 12. The parking switch 12 is built in a vehicle room, and can be operated by a user. The parking switch 12 is maintained to be normally off, and turned on by an operation of a user. The parking switch 12 may be a momentary switch. The first ECU 10 is connected with a clearance ranging sensor 14 that detects a distance to an obstacle using a sound wave (for example, a supersonic wave) , a radio wave (for example, a millimeter wave), a light wave (for example, a laser), or the like. The clearance ranging sensor 14 may be any sensor as long as it can detect a distance, for example, a laser radar, a millimeter- wave radar, a supersonic radar, or others including a stereo vision camera.

The first ECU 10 is connected with a back- monitor camera 16 to capture a scene in back of the vehicle covering a predetermined angle.

Based on a detection result by the clearance ranging sensor 14 (detection result of a parking space) , and/or a processed result of an image captured by the back-monitor camera 16 (for example, a result of recognized white lines) and the like, the first ECU 10 executes parking support control.

The second ECU 20 includes an automatic engine stop function. The automatic engine stop function may be an arbitrary function including an S&S (Stop & Start) or the like. The automatic engine stop function may be accompanied by an engine restart function.

Based on the vehicle speed information and the like, the second ECU 20 determines whether a predetermined S&S start condition is satisfied, and if determining that the predetermined S&S start condition is satisfied, the second ECU 20 has the automatic engine stop function operate. Having the automatic engine stop function operate includes stopping the engine. The S&S start condition includes a condition that the vehicle speed is less than or equal to a predetermined vehicle speed V_th (referred to as the "E/G-stop vehicle speed V_th" below) . The E/G-stop vehicle speed V_th may be zero or a speed within a low vehicle speed region, for example, 8 km/h, or may be variable. Note that the S&S start condition may include other arbitrary conditions, for example, an open fault of the battery is not detected; the brake pedal is stepped on; the magnitude of a booster negative pressure is greater than or equal to a predetermined value; air- conditioning state and a state of charge (SOC) of a battery; road gradient and the like. Logical AND may be taken with these conditions.

The brake ECU 30 controls a brake actuator (not shown) . The brake ECU 30 supplies vehicle speed information calculated based on wheel speed sensors (not shown) to the first ECU 10 and the second ECU 20, for example, via a CAN. Note that the first ECU 10 and/or the second ECU 20 may obtain the vehicle speed information from the other ECUs, or may directly obtain it based on a detection signal from the wheel speed sensors. Also, instead of, or in addition to the information from the wheel speed sensors, the first ECU 10 and/or the second ECU 20 may obtain the vehicle speed information from change of the vehicle position from a GPS receiver, or the rotational speed of the output shaft of the transmission.

FIG. 2 is a flowchart illustrating an example of an S&S prohibition request generation process executed by the first ECU 10. The process illustrated in FIG. 2 may be repeatedly executed for predetermined cycles while the ignition switch of the vehicle is in an on state.

At Step S200, the first ECU 10 determines whether the parking switch 12 is in an on state. If the parking switch 12 is in an on state, the process for this cycle goes forward to Step 202; otherwise, the process for this cycle ends. Note that if the parking switch 12 is a momentary switch, once the parking switch 12 is turned on, then, the first ECU 10 may maintain the on state of the parking switch 12 (internal on state) until a predetermined off condition is satisfied. The predetermined off condition may include conditions with which logical OR is taken, for example, that the driver has operated the steering wheel (a torque detected by a steering torque sensor is greater than or equal to a predetermined value) ; the driver has stepped on the accelerator pedal too much (the throttle opening detected by a throttle sensor is greater than or equal to a predetermined opening) ; the driver has operated the parking brake (the parking brake switch is in an on state) ; the vehicle skids down forward or stands still when the driver has released an operation of the brake pedal (the stop lamp switch is off, or, the brake master cylinder pressure is less than or equal to a predetermined value, and the vehicle speed is greater than or equal to zero) ; and the like.

At Step S202, based on the latest vehicle speed information, the first ECU 10 determines whether the speed is less than or equal to the E/G- stop vehicle speed V_th. If the speed is less than or equal to the E/G-stop vehicle speed Vt r the process for this cycle goes forward to Step 204; otherwise, the process for this cycle ends.

At Step S204, the first ECU 10 determines whether other conditions are satisfied. The other conditions may be arbitrary conditions that need to be satisfied to have the parking support control function operate. For example, the other conditions may include a signal indicating an abnormality of the clearance ranging sensor 14 or a signal indicating an abnormality of the back-monitor camera 16 is not output, and the like. Note that if there are no other conditions, Step 204 may be omitted. If the other conditions are satisfied, the process for this cycle goes forward to Step 206; otherwise, the process for this cycle ends.

At Step S206, the first ECU 10 outputs an S&S prohibition request. The S&S prohibition request is a signal that requests the second ECU 20 not to operate the automatic engine stop function.

Note that if the automatic engine stop function operates while the parking support control function operates, a power supply voltage may become insufficient due to stoppage of power generation by an alternator (not shown) , which may disturb the operation of the parking support control function. For example, if the operation of the parking support control function includes steering support control using electric power steering, inconvenience may arise where responsiveness of the electric power steering gets worse. Also, reduction of a cranking voltage for an engine restart accompanying the automatic engine stop function may cause inconvenience where a reset is generated in a microcomputer (for example, a reset of a learning function) .

In this regard, according to the process illustrated in FIG. 2, when the parking switch 12 is in an on state, and the speed is less than or equal to the E/G-stop vehicle speed V_th, an S&S prohibition request is output. If the S&S prohibition request is output, basically (exceptions will be described later) , a state is generated by the second ECU 20 in which the automatic engine stop function does not operate. Therefore, according to the process illustrated in FIG. 2, the inconvenience can be reduced that could be caused when the automatic engine stop function operates while the parking support control function operates.

Note that, in the example illustrated in FIG. 2, although the first ECU 10 determines whether the speed is less than or equal to the E/G-stop vehicle speed V_th at Step 202, it may determine whether the vehicle speed is less than or equal to the predetermined vehicle speed (≠ the E/G-stop vehicle speed V_th) · This takes a read error difference of the vehicle speed (described later) that may be generated between the first ECU 10 and the second ECU 20, into account. Therefore, the predetermined vehicle, speed may be, for example, less than the E/G-stop vehicle speed V_th by the predetermined error difference. The predetermined error difference may be determined, for example, depending on the read error difference of the vehicle speed that may be generated between the first ECU 10 and the second ECU 20. Also, from the same viewpoint, at Step 202, the first ECU 10 may determine whether a state continues for a predetermined time or longer during which the vehicle speed is less than or equal to the predetermined vehicle speed.

Note that, in the example illustrated in FIG. 2, after outputting a first S&S prohibition request, the first ECU 10 determines whether the predetermined conditions are satisfied (Steps S200 to S204) for each predetermined cycle. Alternatively, after outputting a first S&S prohibition request, the first ECU 10 may determine whether only some of the predetermined conditions are satisfied for each predetermined cycle.

FIG. 3 is a flowchart illustrating an example of a mask flag setting process executed by the second ECU 20. The process illustrated in FIG. 3 may be an interrupt process that is activated when an S&S prohibition request is received (see Step 300) in a state where an S&S prohibition request flag (described later) is "0" while the ignition switch is turned on.

At Step S300, the second ECU 20 determines whether it receives an S&S prohibition request from the first ECU 10. Namely, the second ECU 20 determines whether an S&S prohibition request is output from the first ECU 10. If receiving an S&S prohibition request from the fir-st ECU 10, the process goes forward to Step 302; otherwise, the process transitions into, a state that waits for an output of an S&S prohibition request from the first ECU 10. .

At Step S302, based on the latest vehicle speed information, the second ECU 20 , determines whether the vehicle speed is greater than the E/G- stop vehicle- speed V_th - If the vehicle speed is greater than the E/G-stop vehicle speed V_th r the mask flag setting process goes forward to Step 304; otherwise, the mask flag setting process ends for the S&S prohibition request received this time.

At Step S304, the second ECU 20 sets the mask flag to "1". The mask flag is a flag to determine whether an S&S prohibition request from the first ECU 10 is masked where "1" represents a masked state, and "0" represents a non-masked state. The mask flag is reset to "0" when the ignition switch is turned off or on. Once the mask flag is set to "1" during a trip, then, the state where the flag is set to "1" is maintained until the ignition switch is turned off.

According to the process illustrated in FIG. 3, if the vehicle speed is greater than the E/G-stop vehicle speed V_th when receiving an S&S prohibition request from the first ECU 10, the mask flag can be set to "1". The S&S prohibition request is output only when the speed is less than or equal to the E/G-stop vehicle speed V_th as illustrated in FIG. 2. Therefore, the vehicle speed greater than the E/G-stop vehicle speed V_th when receiving an S&S prohibition request from the first ECU 10, implies that an abnormality occurs in the parking support control function in some way. Abnormalities of the parking support control function include, for example, that the first ECU 10 goes out of control. Therefore, according to the process illustrated in FIG. 3, the mask flag can be set to "1" when an abnormality occurs in the parking support control function .

Note that, in the process illustrated in FIG. 3, as a condition to set the mask flag to "1" when receiving an S&S prohibition request from the first ECU 10, it is necessary that the vehicle speed at the moment is greater than the E/G-stop vehicle speed V_t - However, to take the read error difference of the vehicle speed that could be generated between the first ECU 10 and the second ECU 20 into account, at Step S302, the second ECU 20 may determine whether the vehicle speed is greater than the E/G-stop vehicle speed V_th by a predetermined value (>0), and/or, may determine whether a state continues for a predetermined time or longer during which the vehicle speed is greater than the E/G-stop vehicle speed V_th- Note that the read error difference of the vehicle speed between the first ECU 10 and the second ECU 20 may be generated by a difference of read timings of the vehicle speed signal in a CAN, and such a timing difference may be generated due to a time lag between an output time of an S&S prohibition request from the first ECU 10 and a reception time of the S&S prohibition request at the second ECU 20.

Also, in the process illustrated in FIG. 3, as a condition to set the mask flag to "1" when receiving an S&S prohibition request from the first ECU 10, it is necessary that the vehicle speed at the moment is greater than the E/G-stop vehicle speed V_th- However, instead of, or in addition to the vehicle speed being greater than the E/G-stop vehicle speed V_th one or more other conditions may be added as logical AND or logical OR conditions. In this case, another condition may be an inverse of the output condition of an S&S prohibition request by the first ECU 10. Namely, for a proposition that "if the output condition is satisfied, an S&S prohibition request is output", the other condition may be set that if the contraposition is not true, the mask flag is set to "1". For example, yet another condition (for logical OR conditions, at least one of them) may be that a predetermined off condition is satisfied to release an on state of the parking switch 12; the other condition at Step 204 in FIG. 2 is not satisfied; and the like.

FIG. 4 is a flowchart illustrating an example of an operational method of the automatic engine stop function when receiving an S&S prohibition request from the first ECU 10. The process illustrated in FIG. 4 may be repeatedly executed for predetermined cycles when the automatic engine stop function does not operate (the engine operates), while the ignition switch is turned on.

At Step S400, the second ECU 20 determines whether it receives an S&S prohibition request from the first ECU 10. Namely, the second ECU 20 determines whether an S&S prohibition request is output from the first ECU 10. If receiving an S&S prohibition request from the first ECU 10, the process goes forward to Step 402; otherwise, the process goes forward to FIG. 5 which will be described later.

At Step S402, based on the latest vehicle speed information, the second ECU 20 determines whether the speed is less than or equal to the E/G- stop vehicle speed V_th - If the speed is less than or equal to the E/G-stop vehicle speed V_th r the process for this cycle goes forward to Step 404; otherwise, the process for this cycle ends.

At Step S404, the second ECU 20 determines whether the mask flag is set to "1". If the mask flag is set to "1", the process for this cycle goes forward to Step 406, or if the mask flag is not set to "1" (namely, the mask flag is set to "0"), the process for this cycle ends.

At Step S406, the second ECU 20 has the automatic engine stop function operate . under conditions that the other S&S start conditions are satisfied. Note that if the other S&S start conditions are not satisfied, the process for this cycle ends. If the other S&S start conditions are satisfied, and the automatic engine stop function starts operating, then, the process in FIG. 4 stops. After that, when the operation of the automatic engine stop function ends (namely, the engine has restarted), the process in FIG. 4 is activated again Note that whether the other S&S start conditions are satisfied may be determined at Step 402, or conversely, the condition at Step 402 may be determined at Step 406 as the other S&S start conditions .

According to the process illustrated in FIG. 4, if the mask flag is set to "0" when receiving an S&S prohibition request from the first ECU 10, the second ECU 20 does not go forward to Step 406, and does not have the automatic engine stop function operate. Thus, when an abnormality does not occur in the parking support function, the automatic engine stop function is prohibited in response to an S&S prohibition request from the first ECU 10. On the other hand, if the mask flag is set to "l'V when receiving an S&S prohibition request from the first ECU 10, the second ECU 20 goes forward to Step 406, and has the automatic engine stop function operate under conditions that the other S&S start conditions are satisfied. Thus, when an abnormality occurs in the parking support control function, an S&S prohibition request from the first ECU 10 can be masked to have the automatic engine stop function operate.

Incidentally, the first ECU 10 may have a self-abnormality detection function to detect by itself that an abnormality occurs in the parking support control function. In this case, when detecting by itself that an abnormality occurs in the parking support control function, the first ECU 10 can stop the parking support control function so that an S&S prohibition request is not output. However, if an abnormality occurs that cannot be detected by such a self-abnormality detection function (for example, the first ECU 10 goes out of control) , an S&S prohibition request may be unnecessarily output. This is the same for a case where the first ECU 10 does not have a self- abnormality detection function. In such a case, an unnecessary S&S prohibition request from the first ECU 10 may reduce operational occasions of the automatic engine stop function, and effects of the automatic engine stop function (fuel efficiency and emission reduction) may not be sufficiently exhibited. In contrast to this, according to the process illustrated in FIG. 4, as described above, when an abnormality occurs in the parking support control function, an S&S prohibition request from the first ECU 10 can be masked on the second ECU 20 side, to continue a state where the automatic engine stop function can operate. Thus, inconvenience can be reduced that could be caused by outputting an S&S prohibition request when an abnormality occurs in the parking support control function, and the effects of the automatic engine stop function (fuel efficiency and emission reduction) can be maintained

FIG. 5 is a flowchart illustrating an example of an operational method of the automatic engine stop function when not receiving an S&S prohibition request from the first ECU 10.

At Step S500, based on the latest vehicle speed information, the second ECU 20 determines whether the speed is less than or equal to the E/G- stop vehicle speed V_th. If the speed is less than or equal to the E/G-stop vehicle speed V_th the process for this cycle goes forward to Step 502; otherwise, the process in FIG. 4 starts from the next cycle .

At Step S502, the second ECU 20 has the automatic engine stop function operate under conditions that the other S&S start conditions are satisfied. Note that if the other S&S start conditions are not satisfied, the process in FIG. 4 starts from the next cycle. If the other S&S start conditions are satisfied, and the automatic engine stop function starts operating, the process in FIG. 5 stops. After that, when the operation of the automatic engine stop function ends (namely, the engine has restarted), the process in FIG. 4 starts from the next cycle. Note that whether the other S&S start conditions are satisfied may be determined at Step 500, or conversely, the condition at Step 500 may be determined at Step 502 as the other S&S start conditions.

Note that although the processes illustrated in FIG. ,.4 - and FIG. 5 are described separately for the sake of explanation, these process may be integrated.

As above, the embodiments have been described in detail. Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention. Also, all or multiple elements in the above embodiments may be combined.

For example, a term of "S&S prohibition request" is used in describing the embodiments above. In this regard, a signal indicating that the parking support control function is operating, or a signal indicating that the parking support control function is in an on state, may function as the S&S prohibition request.

Also, in the embodiments described above, although the mask flag is reset for each trip, the reset timing of the mask flag may be arbitrary. For example, the mask flag may be reset once in multiple trips, may be reset when a predetermined time or a predetermined distance has passed, or may be reset when a predetermined reset input is received. [Description of Reference Symbols]

1 vehicle control apparatus

10 first ECU

12 parking switch

20 second ECU

The present application is based on and claims the benefit of priority of Japanese Priority Application No. 2014-120998 filed on June 11, 2014, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.

Claims

Claim 1. A vehicle- control apparatus, comprising :

a first control unit configured to include a parking support control function, and to output a prohibition request ^' to an automatic engine stop function; and

a second control unit configured to include the automatic engine stop function, and to maintain the automatic engine stop function, contrary to the prohibition request output from the first control unit, when an abnormality occurs in the parking support control function.

Claim 2. The vehicle control apparatus, as claimed in claim 1, wherein the first control unit outputs the prohibition request when a vehicle speed is less than or equal to a predetermined vehicle speed, and a parking switch is in an on state,

wherein the second control unit detects whether the abnormality occurs in the parking support control function when the prohibition request is output in a state where the vehicle speed is greater than the predetermined vehicle speed.

Claim 3. The vehicle control apparatus, as claimed in claim 1 or 2, wherein when the prohibition request is output from the first control unit when the abnormality occurs in the parking support control function, the second control unit has the automatic engine stop function operate when a predetermined condition is satisfied.