JP6511478B2 - Engine stop start control device - Google Patents

Description

  The present invention relates to an engine stop and start control device that controls a function of stopping an engine mounted on a vehicle when a stop condition is met and restarting the engine when a restart condition is met.

  Patent Document 1 describes an automatic stop and start device for a vehicle capable of preventing a battery rise generated by automatic stop-automatic start of an engine. This automatic stop and start device prohibits the automatic stop of the engine and operates the engine until the state of charge of the battery becomes the charge necessary for the start of the engine, even if the predetermined stop condition is satisfied after the start of the engine Let That is, even if the stop condition is satisfied after the engine is started, the automatic stop of the engine is temporarily prohibited instead of the automatic stop as it is conventionally, and the battery charge state becomes the charge state necessary for engine start. Operate the engine up to

JP-A-8-61109

  The automatic stop and start device described in Patent Document 1 described above stops the operation of the engine if the charge state of the battery becomes a charge state necessary for starting the engine, but then the charge state of the battery due to excessive load If the state of charge of the battery falls below the state of charge necessary for starting the engine due to a drop or a detection error of a sensor that detects the state of charge of the battery, the engine is started again. As described above, if the engine is repeatedly stopped and started while the so-called idle stop condition is satisfied, the quietness is reduced due to the vibration generated by the stopping and starting of the engine, and the commercial property of the vehicle is reduced. Do. On the other hand, idle stop is one function that is required from the viewpoint of improving fuel consumption.

  An object of the present invention is to provide an engine stop and start control device capable of suppressing a decrease in the marketability of a vehicle while securing an improvement in fuel efficiency.

In order to achieve the above object, the invention according to claim 1 is
An engine stop start control device (for example, described later, which controls a function of stopping an engine mounted on a vehicle (for example, an engine 101 in an embodiment described later) when a stop condition is satisfied and restarting when a restart condition is satisfied. ECU 113) in the embodiment of
From the stop of the engine due to the establishment of the stop condition, the state of the battery mounted on the vehicle (for example, the battery 107 in the embodiment described later) or the restart of the engine due to the establishment of the restart condition based on the parameters related to the battery An acquisition unit (for example, an automatic stop time measurement unit 155 in an embodiment described later) that acquires an automatic stop time, which is a time until restart;
A control unit (for example, I / S control in an embodiment described later) that prohibits stopping of the engine due to the establishment of the stop condition after the next time when the automatic stop time acquired by the acquisition unit is within a predetermined time Part 157),
An engine stop and start control device.

In the invention described in claim 2 , in the invention described in claim 1 ,
The control unit continues the inhibition control for inhibiting the stop of the engine according to the establishment of the stop condition until the vehicle is in the pause state, and cancels the inhibition control when the vehicle is started again.

In the invention of claim 1, after the stop condition is satisfied and the engine is stopped, the restart condition is satisfied and the engine is restarted within a predetermined time, which causes an event that the engine is stopped and restarted continuously. In this case, to prevent the occurrence of the same event, the prohibition control is performed to prohibit the engine stop even if the stop condition is satisfied. For this reason, the occurrence of the same event after the occurrence of the above event can be suppressed, and the decrease in silence due to vibration or the like generated with the stop and start of the engine can be suppressed.
That is, even if the engine is stopped due to the establishment of the stop condition, if the condition based on the state of the battery or the parameters related to the battery is satisfied and the engine is restarted within the predetermined time, the engine stop prohibition control is subsequently performed. Do. Since the restart condition is based on the condition of the battery or a parameter related to the battery, an event in which the restart is performed immediately after the engine stop is a failure of the sensor that detects the condition related to the battery or the parameter related to the battery It is considered to be the cause. Since the start of the engine uses the torque of the motor driven by the power from the battery, when the engine is stopped, there is a possibility that sufficient power is not supplied from the battery and it can not be restarted. However, as in the present invention, by performing the engine stop prohibition control and not stopping the engine, it is possible to prevent a situation where the engine can not be restarted. Further, by performing the engine stop prohibition control, vibrations and the like due to the stop and start of the engine are not generated, so that the commercial property of the vehicle can be maintained.
On the other hand, it is possible to improve the fuel consumption by the function of so-called idle stop which is stopped by the establishment of the stop condition and restarted by the establishment of the restart condition until the above-mentioned prohibition control is performed. Therefore, it is possible to suppress the decrease in the marketability of the vehicle while securing the improvement of the fuel efficiency.

According to the second aspect of the invention, the engine stop prohibition control set during the period from start to stop of the vehicle, that is, during a certain driving cycle, does not take over to the next driving cycle. Since the battery state detection and sensor learning are performed again when the vehicle is started, it is possible that events that occur immediately after stopping and restarting the engine that occurred during the previous driving cycle may not occur during the next driving cycle. is there. Therefore, it is possible to appropriately determine whether or not the engine stop prohibition control is necessary by not taking over the prohibition control over the driving cycle.

It is a block diagram showing the internal configuration of the vehicle provided with the engine stop start control device of one embodiment. It is a block diagram showing an internal configuration of ECU which controls an idle stop function. FIG. 10 is a timing chart when idle stop with a short automatic stop time of less than 5 seconds occurs three times and idle stop prohibition control is performed. FIG. It is a flowchart which shows the flow of the process which an I / S control part performs.

  Hereinafter, an embodiment of a vehicle provided with an engine stop and start control device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an internal configuration of a vehicle provided with an engine stop and start control device according to one embodiment. The vehicle shown in FIG. 1 includes an engine (ENG) 101, a starter motor (hereinafter simply referred to as "starter") 103, a transmission (T / M) 105, a battery (BAT) 107, and a vehicle speed sensor 109. A battery sensor 111 and an ECU 113 are provided. In the vehicle, the motive power output from the engine 101 is transmitted to the drive wheels DW and DW via the transmission 105, the differential gear 8 and the left and right axles 9 and 9. The thick solid lines in FIG. 1 indicate mechanical connection, the double dotted lines indicate power wiring, and thin solid arrows indicate control signals or detection signals.

  Hereinafter, each component which the vehicle of FIG. 1 has will be described.

  The engine 101 outputs motive power for the vehicle to travel. The rotation shaft of the engine 101 is connected to the input shaft of the transmission 105 and the rotor of the starter 103.

  The starter 103 is an electric motor that starts the engine 101.

  The transmission 105 shifts the power from at least one of the engine 101 and the starter 103 at a predetermined gear ratio and transmits it to the drive wheels DW. The transmission gear ratio of the transmission 105 is changed in accordance with an instruction from the ECU 113. The transmission 105 includes a clutch CL that connects and disconnects the power transmission path between the engine 101 and the drive wheels W, W.

  The battery 107 includes a plurality of storage cells connected in series or in parallel. The battery 107 is, for example, a lead storage battery.

  The vehicle speed sensor 109 detects the traveling speed (vehicle speed VP) of the vehicle. A signal indicating the vehicle speed VP detected by the vehicle speed sensor 109 is sent to the ECU 113.

  The battery sensor 111 detects an output (terminal voltage, charging / discharging current) of the battery 107, and detects an SOC (State Of Charge) or the like that indicates a charging state of the battery 107. A signal indicating the SOC detected by the battery sensor 111, the terminal voltage, the integrated value of the charging / discharging current, etc. is sent to the ECU 113.

  The ECU 113 performs operation control of the engine 101, drive control of the starter 103, shift control of the transmission 105, and the like. Further, the ECU 113 controls a function (idle stop function) of stopping the idling operation of the engine 101 while parking or waiting for a signal, for the purpose of improving fuel consumption in traveling of the vehicle. FIG. 2 is a block diagram showing an internal configuration of the ECU 113 that controls the idle stop function. As shown in FIG. 2, the ECU 113 has a stop condition satisfaction determining unit 151, a restart condition satisfaction determining unit 153, an automatic stop time measuring unit 155, and an I / S control unit 157. Hereinafter, each component which ECU113 has is demonstrated.

  The stop condition satisfaction determination unit 151 performs idle stop based on the state of the vehicle including the accelerator pedal opening degree (AP opening degree) according to the accelerator pedal operation by the driver of the vehicle and the vehicle speed VP obtained from the vehicle speed sensor 109. It is determined whether a condition for execution, that is, a condition for stopping the engine 101 (stop condition) is satisfied. When the stop condition is satisfied, the stop condition satisfaction determination unit 151 performs processing for stopping the engine 101 in accordance with the condition set by the I / S control unit 157 described later.

  The restart condition satisfaction determination unit 153 determines the condition for canceling the idle stop, that is, the condition for restarting the engine 101 based on the AP opening degree and the condition of the vehicle including the battery information obtained from the battery sensor 111 It is determined whether or not the start condition is satisfied. The restart condition satisfaction determination unit 153 performs processing for starting the engine 101 when the restart condition is met.

  The automatic stop time measuring unit 155 measures the time from the time ts when the stop condition is satisfied and the engine 101 is stopped to the time tr when the restart condition is satisfied and the engine 101 is restarted (hereinafter referred to as “automatic stop”). "Time".) Measure td (= tr-ts).

  As shown in FIG. 3, the I / S control unit 157 performs control to prohibit idle stop (I / S) having a short automatic stop time td of less than 5 seconds three times. When the inhibition control of the idle stop by the I / S control unit 157 is performed, the stop condition satisfaction determination unit 151 does not perform the process for stopping the engine 101 even if the stop condition is satisfied. The I / S control unit 157 continues the prohibition control until the ignition switch (IGSW) is turned off and the vehicle is in the resting state, and releases the ignition switch when the ignition switch is turned on again to start the vehicle.

  FIG. 4 is a flowchart showing the flow of processing performed by the I / S control unit 157. As shown in FIG. 4, the I / S control unit 157 determines whether the ignition switch (IGSW) is turned on to start the vehicle (step S101), and when the vehicle is started, the process proceeds to step S103. In step S103, the I / S control unit 157 initializes the number N of occurrences of idle stop less than 5 seconds to 0 and cancels the idle stop prohibition control set during the previous driving cycle.

  Next, the I / S control unit 157 acquires the automatic stop time td measured by the automatic stop time measurement unit 155 (step S105). Next, the I / S control unit 157 determines whether the automatic stop time td acquired in step S105 is less than 5 seconds (td <5 seconds) (step S107), and if td <5 seconds The process proceeds to step S109, and if td 秒 5 seconds, the process returns to step S105. In step S109, the I / S control unit 157 increments the number of occurrences N. Next, the I / S control unit 157 determines whether the occurrence number N has reached 3 (step S111). If the occurrence number N = 3, the process proceeds to step S113, and the occurrence number N is less than 3 If there is, the process returns to step S105.

  In step S113, the I / S control unit 157 performs idle stop prohibition control so that the stop condition satisfaction determination unit 151 does not perform the engine stop process even if the stop condition is satisfied. The I / S control unit 157 continues the prohibition control set in step S113 until the ignition switch is turned off and the vehicle is in the resting state.

  The automatic stop time td of the idle stop, which is counted as the number of occurrences N, used in step S107 is not limited to less than 5 seconds. The automatic stop time td is set to a time interval in which the occupant of the vehicle tends to feel uncomfortable when vibrations and the like occur frequently due to repetition of stop and restart of the engine 101.

  Further, the number of occurrences N for starting the idle stop inhibition control used in step S111 is not limited to three. However, in the present embodiment, it is considered that the occurrence of three idle stops having a short automatic stop time td is hardly occurred in a situation where the vehicle normally travels. For example, even when traveling on a heavily congested road in the center of a city, idle stop less than 5 seconds is generated twice at most. For this reason, in the present embodiment, the number of occurrences N for starting the idle stop inhibition control, which is used in step S111, is set to three.

  As described above, in the present embodiment, when three short idle stops such as the automatic stop time td of less than 5 seconds occur, the subsequent idle stops are prohibited. For this reason, after the said prohibition control, the vibration accompanying stop and start of the engine 101 which caused idle stop does not generate | occur | produce. As a result, the fuel consumption can be improved by the idle stop until the prohibition control is performed, and after the prohibition control, the decrease in silence due to the vibration of the idle stop can be suppressed. Therefore, it is possible to suppress the decrease in the marketability of the vehicle while securing the improvement of the fuel efficiency.

  Further, in the present embodiment, although the above-mentioned prohibition control can be executed, a situation where a short idle stop such as less than 5 seconds occurs as many as three times is hardly found in normal traveling. Therefore, the situation is considered to be an event that occurs because the restart condition is satisfied even if the idle stop is started due to the state deterioration due to the deterioration or fatigue of the battery or the failure of the battery sensor 111. Since starting of the engine uses the torque of the starter 103 driven by the power from the battery 107, when the engine 101 is stopped by idle stop, sufficient power is not supplied from the battery 107 in such a state, and the engine 101 is restarted. There is a possibility that it can not start. However, it is possible to prevent the situation where the engine 101 can not be restarted by not performing the idle stop prohibition control and not stopping the engine 101 as in the present embodiment.

  Also, the idle stop prohibition control set during a driving cycle is not carried over to the next driving cycle. Since the state detection of the battery 107 and the learning of the battery sensor 111 are performed again when the vehicle is started, the frequent occurrence of a short idle stop occurring in the previous driving cycle may not occur in the next driving cycle. . Therefore, it is possible to appropriately determine the necessity of the prohibition control by not taking over the idle stop prohibition control over the driving cycle.

  The present invention is not limited to the above-described embodiment, and appropriate modifications, improvements, and the like can be made. For example, in a vehicle, in place of the starter 103, an ISG (Integrated Starter Generator) performing start of the engine 101 and generation of an assist torque for assisting the output of the engine 101 or at least a part of the output of the engine 101. May be mounted. In this case, since ISG uses relatively large power, a battery 107 capable of supplying a high voltage of, for example, 100 to 200 V, in which storage cells such as a lithium ion battery or a nickel hydrogen battery are connected in series is used as the battery 107 Used.

101 engine (ENG)
103 Starter motor (SMOT)
105 Transmission (T / M)
107 Battery (BAT)
109 Vehicle speed sensor 111 Battery sensor 113 ECU
151 Stop condition satisfaction judgment unit 153 Restart condition satisfaction judgment unit 155 Automatic stop time measurement unit 157 I / S control unit

Claims (2)

An engine stop and start control device that controls a function of stopping an engine mounted on a vehicle when a stop condition is met and restarting the engine when a restart condition is met,
Automatic stop time, which is the time from the stop of the engine due to the fulfillment of the stop condition to the restart of the engine due to the fulfillment of the restart condition based on the condition of the battery mounted on the vehicle or the parameters relating to the battery The acquisition unit to acquire,
A control unit that prohibits stopping of the engine by establishment of the stop condition after the next time, when the automatic stop time acquired by the acquisition unit is within a predetermined time;
An engine stop and start control device comprising: The engine stop and start control device according to claim 1 , wherein
The control unit continues the inhibition control for inhibiting the stop of the engine based on the establishment of the stop condition until the vehicle is in the pause state, and cancels the inhibition control when the vehicle restarts. Start control device.

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