JP6295879B2 - Engine automatic stop / restart device - Google Patents

Description

  The present invention relates to an engine automatic stop / start device.

  2. Description of the Related Art Conventionally, a technique for performing so-called idling stop control that automatically stops an engine when a predetermined automatic stop condition is satisfied and restarts the engine when a predetermined restart condition is satisfied is known. The restart condition includes that the release of the brake operation is determined. According to this idling stop control, an effect such as reduction in fuel consumption of the engine can be obtained.

  Moreover, in the thing of patent document 1, when the brake operation is cancelled | released just before a stop during the deceleration after an engine automatic stop, an engine is maintained in the state which stopped regardless of cancellation | release of the brake operation. The For this reason, the engine is not restarted even if the driver releases the brake operation in order to relieve the vehicle posture change that occurs when the vehicle is stopped.

JP 2013-170530 A

  However, the brake operation is not canceled immediately before stopping for the purpose of alleviating the change in vehicle posture (shock reduction). For example, when stopping at an intersection, the display of the traffic light changes to a green light immediately before stopping. In such a case, it is considered that the brake operation is released for the purpose of restarting the vehicle. In addition, when the preceding vehicle is stopped or traveling at a low speed, if the preceding vehicle accelerates, it is considered that the brake operation is released for the purpose of accelerating following the preceding vehicle. In this regard, in the device described in Patent Document 1, since the engine is not restarted even if the brake operation is released immediately before stopping, there is a problem that the engine cannot be restarted in accordance with the driver's intention. In this case, there is a concern that the start of the vehicle is delayed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to suitably perform engine restart, and thus to allow the vehicle to restart properly.

  Hereinafter, means for solving the above-described problems, and actions and effects thereof will be described.

  The present invention stops the engine when a predetermined automatic stop condition is satisfied during traveling of the host vehicle, and then restarts the engine when a predetermined restart condition including release of a brake operation is satisfied. A brake determining means for determining whether or not to release the brake operation in a predetermined immediately preceding stop period after the automatic stop of the engine and immediately before stopping, and a situation where acceleration of the host vehicle is required Predetermined conditions to be determined are set, condition determining means for determining success or failure of the predetermined condition in the period immediately before stopping, and determination that the brake operation is released and the predetermined condition is not satisfied in the period immediately before stopping If it is determined that the brake operation is released and the predetermined condition is satisfied without restarting the engine, the engine is restarted. Characterized in that it comprises a control means to restart the down, the.

  Rather than always restarting the engine when the brake operation is released in a predetermined period immediately before stopping, the engine is restarted if a predetermined condition that requires acceleration of the host vehicle is satisfied. I tried to make it. As a result, when the host vehicle needs to be accelerated, the engine can be restarted immediately in preparation for the acceleration, and the host vehicle can be properly restarted.

Schematic diagram of engine automatic stop / restart control system Flow chart showing engine automatic stop / restart processing Timing chart showing automatic engine stop and restart Timing chart showing engine restart

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. The present embodiment embodies a vehicle equipped with an engine, and performs idling stop control using an electronic control unit (hereinafter referred to as ECU). FIG. 1 is a diagram showing a schematic configuration of an engine automatic stop / restart system according to the present embodiment.

  As shown in FIG. 1, an automatic transmission 12 is connected to the engine 11. The engine 11 is a spark ignition type gasoline engine, and includes an injector 14 and an ignition device 15 as fuel injection means for each cylinder. In addition, the engine 11 is provided with a starter device 16 as a starting device that applies initial rotation (cranking rotation) to the engine 11 when the engine is started. The engine 11 is not limited to a gasoline engine, and may be a diesel engine. The starter device 16 may be an ISG (Integrated Starter Generator).

  The automatic transmission 12 includes a torque converter and a transmission unit that converts the driving force transmitted by the torque converter into a driving force necessary for the host vehicle. A wheel 19 is connected to the output shaft of the automatic transmission 12 via a drive shaft 17 and a differential gear 18.

  The ECU 21 is an electronic control device including a known microcomputer and the like. Based on the detection results of various sensors provided in the system, the ECU 21 performs various control such as fuel injection amount control by the injector 14 and ignition control by the ignition device 15. Engine control and drive control of the starter device 16 are performed.

  For details on the sensors, the ECU 21 includes an accelerator sensor 22 that detects an operation amount of an accelerator pedal as an accelerator operation member, a brake sensor 23 that detects an operation amount of a brake pedal, a speed sensor 24 that detects a vehicle speed, A radar device 25 that detects the relative speed of the host vehicle with respect to the vehicle and the like, a camera device 26 that images the front of the host vehicle, and the like are connected, and signals from these sensors and devices are sequentially input to the ECU 21. ing.

  The radar device 25 includes a high-frequency module that is attached to the front surface of the vehicle and includes an antenna that transmits and receives radio waves, and a control circuit that controls the radio waves, and transmits radio waves from the antenna and reflects the waves reflected by the preceding vehicle. Receive. Based on the received radio wave, the relative speed of the host vehicle with respect to the preceding vehicle is detected.

  The camera device 26 is attached to a windshield or the like of a vehicle, and includes a lens, an image sensor, and an image processing device. A front image that has passed through the lens is captured by the image sensor, and the image processing device captures the image. Necessary images such as traffic lights are detected from the images.

  In general, the idling stop control automatically stops the engine 11 when a predetermined automatic stop condition is satisfied, and then restarts the engine 11 when a predetermined restart condition is satisfied. In this case, the automatic stop condition includes, for example, that the vehicle speed of the host vehicle is in the engine automatic stop speed range (for example, vehicle speed ≦ 10 km / h) and the accelerator operation is released. In addition, the restart condition includes, for example, that an accelerator operation is started and a brake operation is released.

  In the present embodiment, whether or not the brake operation is released when the vehicle speed of the host vehicle is in the speed range immediately before stopping (for example, 0 km / h <vehicle speed ≦ 5 km / h) after the engine of the host vehicle is stopped. Then, it is determined whether or not a predetermined condition that requires acceleration of the host vehicle is satisfied. If it is determined that the brake operation is released and the predetermined condition is not satisfied, the engine 11 is not restarted, and the brake operation is released and it is determined that the predetermined condition is satisfied. Then, the engine 11 is restarted.

  Further, in the present embodiment, in determining whether or not a predetermined condition that requires acceleration of the host vehicle is satisfied, a determination based on the traveling of the preceding vehicle and a determination based on the display of the traffic light is made according to the presence or absence of the preceding vehicle. Switch to either. When there is a preceding vehicle, when the preceding vehicle moves away from the own vehicle, it is determined that the own vehicle needs to be accelerated, and the engine 11 is restarted. On the other hand, when there is no preceding vehicle and the traffic light ahead of the host vehicle is a green signal, it is determined that the host vehicle needs to be accelerated and the engine 11 is restarted.

  FIG. 2 is a flowchart showing a processing procedure for control of engine automatic stop / restart, and this processing is repeatedly executed by the ECU 21 at a predetermined cycle.

  In FIG. 2, in step S11, it is determined whether or not the engine 11 is stopped. If the determination in step S11 is negative, the process proceeds to step S12. On the other hand, if the determination in step S11 is affirmative, the process proceeds to step S13.

  In step S12, it is determined whether an automatic stop condition for the engine 11 is satisfied. That is, it is determined whether or not the vehicle speed of the host vehicle is in the engine automatic stop speed range and the accelerator operation is released. If the result in Step S12 is negative, this process is temporarily terminated. On the other hand, if the result in step S12 is affirmative, the engine 11 is stopped (step S14).

  In step S13, it is determined whether or not a restart condition for the engine 11 is satisfied. That is, it is determined whether or not an accelerator operation is started or a brake operation is released. If the result in Step S13 is negative, this process is temporarily terminated. On the other hand, if the determination in step S13 is affirmative, the process proceeds to step S15.

  In step S15, it is determined whether or not the establishment of the restart condition in step S13 is due to the release of the brake operation. If the result in Step S15 is negative (when the restart condition in Step S13 is satisfied by an accelerator operation), the engine 11 is restarted (Step S20). On the other hand, if the determination in step S15 is affirmative, the process proceeds to step S16.

  In step S16, it is determined whether or not the vehicle speed of the host vehicle is in the speed range immediately before stopping. If the determination in step S16 is negative, the engine 11 is restarted (step S20). On the other hand, if the result is negative in step S16, the process proceeds to step S17.

  In step S17, it is determined whether there is a preceding vehicle. If the determination in step S17 is affirmative, the process proceeds to step S18. On the other hand, if the result is negative in step S17, the process proceeds to step S19.

  In step S18, it is determined whether or not the preceding vehicle is moving away from the host vehicle. In this case, it is determined whether or not the relative speed of the host vehicle with respect to the preceding vehicle is negative. If the result in Step S18 is negative, this process is temporarily terminated. On the other hand, if the determination in step S18 is affirmative, the engine 11 is restarted (step S20).

  In step S19, it is determined whether the traffic light ahead of the host vehicle is displaying a green light. If the result in Step S19 is negative, this process is temporarily terminated. On the other hand, if the result in step S19 is affirmative, the engine 11 is restarted (step S20).

  FIG. 3 is a timing chart for specifically explaining the processing procedure for the engine automatic stop / restart control. In FIG. 3, (a) and (b) show a case where the restart conditions of the engine 11 immediately before stopping are different, and (a) shows that the engine 11 remains in a stopped state regardless of release of the brake operation immediately before stopping. (B) has shown the case where the engine 11 is restarted according to the brake operation cancellation | release just before stopping. Note that the period from t3 to t5 in FIG. 3A and the period from t13 to t15 in FIG. 3B correspond to the period immediately before stopping.

  In FIG. 3A, when the brake operation is started at the timing t1, the vehicle speed of the host vehicle starts to decrease. When the vehicle speed of the host vehicle decreases to the engine automatic stop speed range (V1 or less in the figure) at timing t2, the engine 11 automatically stops. Thereafter, the vehicle speed of the host vehicle further decreases, and at a timing t3, the vehicle speed decreases to a speed range immediately before stopping (V2 or less in the figure). At the timing t4, for example, for the purpose of suppressing the posture change when the host vehicle is stopped, the brake operation is released by the driver depressing the brake pedal. At this time, since the own vehicle is approaching the preceding vehicle (the relative speed of the own vehicle with respect to the preceding vehicle is positive), it is determined that the situation does not require acceleration of the own vehicle, and the engine 11 is not restarted. The At time t5, the host vehicle stops. After the preceding vehicle starts at timing t6, the engine 11 is restarted when the brake operation is released at timing t7.

  In FIG. 3 (b), the brake operation is started and the engine is automatically stopped (timing t11, t12) as in FIG. 3 (a), and then the speed is reduced to the speed range just before stopping at timing t13. After the preceding vehicle starts at timing t14, the brake operation is released at timing t15. At this time, since the preceding vehicle is moving away from the own vehicle (the relative speed of the own vehicle with respect to the preceding vehicle is negative), it is determined that the own vehicle needs to be accelerated, and the engine 11 Is restarted. The accelerator operation is started at timing t16.

  According to the present embodiment described above, the following excellent effects are obtained.

  When the brake operation is released in the speed range immediately before stopping, the engine 11 is not always restarted, but it is determined whether or not the vehicle needs to be accelerated, and the vehicle needs to be accelerated. Is configured to restart the engine 11. As a result, when the host vehicle needs to be accelerated, the engine 11 can be restarted immediately in preparation for the acceleration, and the host vehicle can be properly restarted (re-accelerated).

  When the brake operation is released in the speed range immediately before stopping, the determination of whether or not the host vehicle needs to be accelerated is performed based on the relative speed of the host vehicle with respect to the preceding vehicle. When the preceding vehicle moves away (when the relative speed of the host vehicle with respect to the preceding vehicle is negative), it is determined that acceleration of the host vehicle is necessary, and the engine 11 is restarted. For this reason, an appropriate engine restart can be performed in anticipation of the follow-up traveling of the preceding vehicle.

  Whether or not the host vehicle needs to be accelerated when the brake operation is released in the speed range immediately before stopping is determined based on the lighting color of the traffic light in front of the host vehicle. When the traffic light ahead of the host vehicle displays a green signal, it is determined that the host vehicle needs to be accelerated, and the engine 11 is restarted. For this reason, an appropriate engine restart can be implemented in anticipation of the start (acceleration) of the host vehicle according to the display of the traffic light.

  The determination of whether or not the host vehicle needs to be accelerated is made based on the relative speed of the host vehicle with respect to the preceding vehicle when there is a preceding vehicle, and the lighting color of the traffic light ahead of the host vehicle when there is no preceding vehicle. Based on. Thereby, an appropriate engine restart can be implemented irrespective of the presence or absence of a preceding vehicle.

(Other embodiments)
You may change the said embodiment as follows, for example.

  The radar device 25 may be provided on the rear surface of the vehicle, and the engine restart may be performed even when the following vehicle abnormally approaches the host vehicle. Specifically, for example, when step 16 in FIG. 2 is affirmed, the ECU 21 determines whether or not the subsequent vehicle is abnormally approaching the own vehicle due to the relative speed and the separation distance from the subsequent vehicle. If the situation is determined to be abnormally approaching, the engine 11 is restarted. As a result, it is possible to perform an appropriate engine restart in anticipation of the possibility of the subsequent vehicle colliding with the host vehicle.

  ・ It is configured to determine whether or not the host vehicle needs to be accelerated when the host vehicle speed is in the speed range immediately before stopping. In addition to this, while the host vehicle is stopped, the host vehicle It is configured to determine whether or not acceleration is required regardless of whether or not the brake operation is released (see FIGS. 4A and 4B). According to such a configuration, at the timings t21 and t31 in FIG. 4, the preceding vehicle starts when the host vehicle is stopped (FIG. 4A), or when the host vehicle is stopped. When the traffic light in front of the host vehicle displays a green signal (FIG. 4B), the engine 11 is restarted regardless of whether or not the brake operation is released. Accordingly, it is possible to perform an appropriate engine restart in anticipation of the following start of the own vehicle with respect to the preceding vehicle and the start of the own vehicle according to the display of the traffic light. On the other hand, because the preceding vehicle is stopped when the host vehicle is stopped, or the traffic light in front of the host vehicle is displaying a red signal, the engine 11 can be operated regardless of whether the brake operation is released or not. Continue to stop. Thereby, even if brake operation is cancelled | released unexpectedly, the engine 11 is not restarted and it can suppress fuel consumption.

  -It is good also as a structure which detects the deceleration of the own vehicle and restarts the engine 11 when the deceleration of the own vehicle is below a predetermined value when the vehicle speed of the own vehicle is in the speed range immediately before stopping. According to this configuration, if the deceleration of the host vehicle is greater than the predetermined value, it is determined that the driver intends to stop the vehicle, and the engine 11 continues to stop, but the deceleration of the host vehicle is equal to or less than the predetermined value. In this case, it is determined that the driver intends to drive the host vehicle at a low speed, and the engine 11 is restarted. For this reason, it is possible to perform an appropriate engine restart in consideration of whether or not the host vehicle is traveling at a low speed.

  ・ When the traffic light is displaying a green light, the vehicle must be accelerated. However, this is not limited to the case where the traffic light is displaying a green light, and the traffic light displays an arrow signal. The vehicle may be in a situation that requires acceleration of the host vehicle.

  -Whether the host vehicle needs to be accelerated is determined based on the relative speed of the host vehicle with respect to the preceding vehicle when there is a preceding vehicle, and based on the lighting color of the traffic light ahead of the host vehicle when there is no preceding vehicle. However, when there is a preceding vehicle, this is performed based on the relative speed of the own vehicle with respect to the preceding vehicle and the lighting color of the traffic light in front of the own vehicle. According to such a configuration, for example, even when the preceding vehicle accelerates (starts) immediately before the host vehicle stops, the engine 11 is not restarted if the traffic light ahead of the host vehicle is a red signal. As a result, it is possible to perform an appropriate engine restart in anticipation of acceleration (start) of the host vehicle in accordance with the following traveling of the preceding vehicle and the display of the traffic light.

11 ... Engine, 21 ... ECU (Engine automatic stop / restart device)

Claims (6)

An engine automatic stop / restart device that stops the engine (11) when a predetermined automatic stop condition is satisfied during traveling of the host vehicle, and then restarts the engine when a predetermined restart condition including release of a brake operation is satisfied. (21)
Brake determination means for determining whether or not to release the brake operation in a predetermined period immediately before stopping after the engine is automatically stopped and immediately before stopping;
A predetermined condition for determining that the host vehicle needs to be accelerated, and condition determination means for determining whether or not the predetermined condition is met in the period immediately before the stop;
If it is determined that the brake operation is released and the predetermined condition is not satisfied in the period immediately before stopping, the engine is not restarted and the brake operation is released and the predetermined condition is satisfied. If it is determined, control means for restarting the engine,
With
The condition determination means uses the predetermined condition to move the preceding vehicle away from the host vehicle in the period immediately before the stop, and determines whether the predetermined condition is satisfied or not. apparatus. Said condition determining means, according to claim 1, wherein that the front of the traffic signal of the vehicle is in the display to indicate the progress in stopping immediately before the period and the predetermined condition, and judging the success or failure of the predetermined conditions automatic engine stop and restart device according to. An engine automatic stop / restart device that stops the engine (11) when a predetermined automatic stop condition is satisfied during traveling of the host vehicle, and then restarts the engine when a predetermined restart condition including release of a brake operation is satisfied. (21)
Brake determination means for determining whether or not to release the brake operation in a predetermined period immediately before stopping after the engine is automatically stopped and immediately before stopping;
A predetermined condition for determining that the host vehicle needs to be accelerated, and condition determination means for determining whether or not the predetermined condition is met in the period immediately before the stop;
If it is determined that the brake operation is released and the predetermined condition is not satisfied in the period immediately before stopping, the engine is not restarted and the brake operation is released and the predetermined condition is satisfied. If it is determined, control means for restarting the engine,
A preceding vehicle determining means for determining the presence or absence of a preceding vehicle in the period immediately before the stop;
The condition determining means moves the preceding vehicle to a side away from the own vehicle when the preceding vehicle determining means determines that there is a preceding vehicle in the period immediately before stopping, and the preceding vehicle determining means When it is determined that there is no preceding vehicle, at least one of the indication that the traffic signal ahead of the host vehicle is instructed to proceed is set as the predetermined condition, and the success or failure of the predetermined condition is determined. Rue engine automatic stop and restart apparatus. It said condition determining means, that the following vehicle relative to the vehicle is abnormally close at the stop just before the period and the predetermined condition, any one of claims 1 to 3, characterized in that to determine the success or failure of the predetermined conditions The engine automatic stop / restart device according to one item. When the host vehicle is stopped, the second predetermined condition is at least one of the fact that the preceding vehicle moves away from the host vehicle and that the traffic light in front of the host vehicle is instructed to proceed. Second condition determining means for determining success or failure of the predetermined condition;
A second control means for restarting the engine regardless of whether or not the brake operation is released if it is determined that the second predetermined condition is satisfied while the vehicle is stopped;
The engine automatic stop / restart device according to any one of claims 1 to 4 , further comprising: When the host vehicle is stopped, at least one of the fact that the preceding vehicle has stopped with respect to the host vehicle and that the traffic light in front of the host vehicle is instructed to stop is set as the third predetermined condition. Third condition determining means for determining success or failure of the condition;
When it is determined that the third predetermined condition is satisfied while the vehicle is stopped, a third control unit that does not restart the engine regardless of whether or not the brake operation is released;
The engine automatic stop / restart device according to any one of claims 1 to 5 , further comprising:

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