DE102017218735A1 - SYSTEM TO CONTROL A COMBUSTION ENGINE AUTO STOP - Google Patents

Abstract

There is disclosed a system for controlling an engine auto-stop comprising a lane sensor used to detect a lane slope of a road surface on which a vehicle is traveling and an automatic stop-start system that is configured Automatically stopping the engine of the vehicle under one of predetermined auto-stop conditions including a road-slope-related auto-stop condition set based on the detected road slope. In the system for controlling an engine auto-stop, there is provided a malfunction determination section configured to detect a malfunction in the automatic stop-start system (61) after completion of a first predetermined time period when an error occurs in the engine automatic stop-start system (61) persists for the first predetermined time period. In the case where a current lane slope is equal to or greater than a predetermined value, the automatic stop-start system allows the engine to be automatically stopped after a second predetermined time longer than the first predetermined time lapse, when the road slope related, established auto-stop condition persists for the second predetermined time period.

Description

[Technical area]

The present invention relates to a system for controlling an engine auto-stop.

[State of the art]

Certain motor vehicles are equipped with an automatic "stop-start system" which automatically shuts down and restarts the vehicle's internal combustion engine to reduce fuel consumption of the vehicle under certain conditions, such as when the internal combustion engine is otherwise idling.

JP 2012-255383A discloses a known motor vehicle equipped with a stop-start system. This motor vehicle stop-start system shuts down the engine in operation in response to a current road grade (or road grade).

In the known so-called idle-stop vehicle, the failure diagnosis of the stop-start system is performed on the basis of a signal from an on-board tilt sensor after automatically stopping the engine when the engine auto-stop condition set with a road gradient , is equal to or less than a second predetermined threshold that is less than a first predetermined threshold. Until the fault diagnosis is completed, the engine auto stop is prevented at a lane slope exceeding the second predetermined threshold.

[State of the art]

[Patent Literature]

Patent Literature 1: JP 2012-255383A

[Summary]

[Technical problem]

The motor vehicle with the known auto-start system has a potential problem that the motor vehicle may move contrary to the intention of the driver when the motor vehicle comes to a standstill after entering a steep slope from a flat lane before the fault diagnosis is completed, which is initiated by the automatic stopping of the internal combustion engine.

An object of the present invention is to provide a system for controlling an engine auto-stop that can prevent a motor vehicle from moving along a slope having a large road slope even in case of malfunction in an automatic stop-start system.

[Solution to the problem]

According to the present embodiment, there is provided a system for controlling an engine auto-stop including a lane sensor used to detect a lane slope of a road surface on which a vehicle is traveling, and an automatic stop-start system. configured to automatically stop an internal combustion engine of the vehicle under any one of predetermined auto-stop conditions including a road-slope-related auto-stop condition set on the basis of the detected road incline, wherein a malfunction Determination section configured to detect a malfunction in the automatic stop-start system after completion of a first predetermined time period when an error in the automatic stop-start system remains for the first predetermined time period; and wherein the automatic stop-start system, in the case where a current road gradient is equal to or greater than a predetermined value, allows automatic stopping of the internal combustion engine after the completion of a second predetermined time period longer than the first predetermined time period when the road gradient related established auto-stop condition persists for the second predetermined time period.

Advantageous Effect of the Invention

According to the invention, there is provided a system for controlling an engine auto-stop which, even in the event of a malfunction in an automatic stop-start system, can prevent a motor vehicle from moving along a slope having a large road gradient.

list of figures

• 1 FIG. 12 is a schematic diagram of a vehicle system of a vehicle in which a system for controlling an engine auto-stop may be used; FIG.
• 2 Figure 12 is a block diagram of the components of the system for controlling an engine auto-stop;
• 3 FIG. 12 shows a first predetermined time period (T1) required for a determination of a malfunction in an automatic stop-start system, a second predetermined time period (T2) necessary for a determination of a road slope related auto-stop condition is required when a current lane slope is greater than or equal to a predetermined value, and another second predetermined period (T3) required for a determination of the lane slope-related auto-stop condition when a current lane slope is less than the predetermined value;
• 4 FIG. 10 is a flow chart illustrating an exemplary algorithm for detecting the malfunction in the automatic stop-start system; FIG.
• 5 FIG. 10 is a flowchart illustrating an exemplary algorithm for determining the road grade related auto-stop condition; FIG.
• 6 FIG. 10 is a flowchart illustrating an exemplary algorithm for controlling engine auto-stop. FIG.

[Description of an embodiment (s)]

A system for controlling an engine auto-stop includes a lane sensor used to detect a lane slope of a road surface on which a vehicle is traveling, and an automatic stop-start system configured to control an engine of the vehicle Vehicle under one of predetermined auto-stop conditions, which include a road slope related auto-stop condition, which is determined on the basis of the detected road gradient automatically stop. In the system for controlling the engine auto-stop, there is provided a malfunction determination section configured to detect a malfunction in the automatic stop-start system after completion of a first predetermined time period when an error occurs in the automatic stop-start system. Start system persists for the first predetermined period of time. In the case where a current lane slope is equal to or greater than a predetermined value, the automatic stop-start system allows the engine to be automatically stopped after a second predetermined time longer than the first predetermined time lapse, when the road slope related, established auto-stop condition persists for the second predetermined time period. This configuration also prevents the motor vehicle from moving on a steep slope in the event of a malfunction in the automatic stop-start system.

Referring to the accompanying drawings 1 a vehicle system of a motor vehicle in the form of an electric hybrid vehicle, wherein the system is not limited to an electric hybrid vehicle and in the electric hybrid vehicle, a system for controlling an engine auto-stop can be used.

Referring to 1 For example, a motor vehicle may be an electric hybrid vehicle 1 but is not limited to this. In the present embodiment, the hybrid electric vehicle includes 1 The following: an internal combustion engine 2 in the form of an internal combustion engine; a transmission 3; a motor generator 4; a set of drive wheels, with only one shown and designated 5; a hybrid control unit (HCU) 10 configured to the hybrid electric vehicle 1 to control comprehensively; an internal combustion engine control module (ECM) 11 configured to the internal combustion engine 2 to control; a transmission control module (TCM) 12 configured to control the transmission 3; an integrated starter-generator control module (ISGCM) 13; an inverter control module (INVCM) 14; a low voltage battery management system (LVBMS) 15; and a high voltage battery management system (HVBMS) 16.

The internal combustion engine 2 is formed with a plurality of cylinders. The present example is the internal combustion engine 2 a four-stroke internal combustion engine, which means that four piston strokes are necessary to complete one cycle. The cycle includes four different processes: intake, compression, combustion and power strokes, as well as exhaust stroke.

An integrated starter generator (ISG) 20 and a starter 21 are operative with the internal combustion engine 2 connected. The ISG 20 is connected via a belt 22 to a crankshaft 18 of the internal combustion engine 2 connected. The ISG 20 acts as an electric motor to the internal combustion engine 2 upon starting an electric current, and it functions as an electric power generator to generate an electric current upon input of a torque from the crankshaft 18.

In the present embodiment, under the control of the ISGCM 13, the ISG 20 functions as an electric motor to the internal combustion engine 2 Restart after an internal combustion engine auto-stop feature the internal combustion engine 2 automatically shut off instead of allowing the internal combustion engine 2 idle. The ISG 20 acts as the engine to one To provide power assistance when the internal combustion engine 2 the electric hybrid vehicle 1 drives.

The starter 21 includes an engine and gears, which are not shown. The starter 21 sets a starting torque for the internal combustion engine 2 ready by the crankshaft 18 is rotated with the engine. The internal combustion engine 2 is started by the starter 21 in this way, so that it is restarted by means of the ISG 20 after the engine auto-stop function, the internal combustion engine 2 automatically shut off.

The transmission 3 changes the rotational speed of the output rotation of the internal combustion engine 2 to energize the set of drive wheels 5 via a drive shaft 23. The transmission 3 includes a speed change mechanism 25 with permanent engagement of a parallel shaft gear mechanism; a clutch 26 in the form of a normally closed type dry single plate clutch; and a differential gear 27th

As described, the transmission 3 is configured as an automatic transmission, referred to as an automated manual transmission (AMT), in which a gear change is performed by means of an actuator (not shown) controlled by the TCM 12.

In detail, the actuator changes gear in the speed change mechanism 25, and another actuator engages or disengages the clutch 26. The differential gear 27 transmits a force from the speed-change mechanism 25 to the drive shaft 23.

The motor generator 4 is connected to the differential gear 27 via a power transmission mechanism 28 such as a chain, etc. The motor generator 4 functions as an electric motor.

As described, the electric hybrid vehicle 1 configured for a parallel hybrid system, where both an energy from the internal combustion engine 2 as well as by the motor generator 4 can be used for a drive that the electric hybrid vehicle 1 by at least one of the energy from the internal combustion engine 2 and driven by the motor generator 4.

The motor generator 4 may function as a power generator that enables power generation under certain circumstances when the electric hybrid vehicle 1 moves. It is not absolutely necessary to couple the motor generator 4 with the differential gear 27. The motor generator 4 may be at any point on an axis between the engine 2 and the drive wheel 5 are coupled.

The electric hybrid vehicle 1 includes a first power storage device 30; a low voltage power pack 32 including a second power storage device 31; a high voltage power pack 34 including a third power storage device 33; a high voltage cable 35; and a low voltage cable 36.

The first power feeding apparatus 30, the second power storage apparatus 31, and the third power storage apparatus 33 are secondary batteries or rechargeable batteries. In the present embodiment, the first power storage device 30 is in the form of a lead-acid battery. The second power storage device 31 has a higher output power and a higher energy density than the first power storage device 30.

The second power storage device 31 is rechargeable in a shorter period of time than the first power storage device 30. In the present embodiment, the second power storage device 31 is in the form of a lithium ion battery. The second power storage device 31 may be in the form of a nickel metal hydride battery.

Each of the first and second power storage devices 30 and 31 is a low-voltage battery in which the number of cells is set so as to be capable of generating an output voltage of about 12 volts. The third power storage device 33 is in the form of a lithium ion battery, for example.

The third power storage device 33 is a high voltage battery in which the number of cells is set to produce an output voltage of, for example, 100 volts higher than one of the first and second power storage devices. Device 30 and 31 generated output voltage is. The state of the third power storage device 33, such as a remaining capacity, is managed by the HVBMS 16.

The electric hybrid vehicle 1 is provided with groups of electrical loads, ie a group of general loads 37 and a group of important loads 38. The general loads 37 and the important loads 38 are electrical loads except for the starter 21 and the ISG 20.

The important loads 38 are those electrical loads that always require a stable power supply. The important loads 38 include an electronic stability control system 38A that controls the vehicle stability of the electric hybrid vehicle 1 improved; an electronic power steering control system 38B that assists a driver in steering by improving the steering effort of the steering wheel; as well as front headlights 38C. In addition, the important loads include 38 lamps and meters within an instrument panel as well as a car navigation system.

The general loads 37 are those electrical loads that are used temporarily and thus do not constantly require a stable power supply compared to the important loads. The general loads 37 include, for example, a windshield wiper and an electric cooling fan that is the internal combustion engine 2 Supplying cooling air.

The low voltage power pack 32 includes switches 40 and 41 and the LVBMS 15 in addition to the second power storage device 31. The first power storage device 30 and the second power storage device 31 are connected via the low voltage cable 36 to the starter 21, the ISG 20 and Connected loads containing the general loads 37 and the important loads 38 to supply a current. With respect to the important loads 38, the first and second power storage devices 30 and 31 are connected in parallel.

The switch 40 is provided in the low voltage cable 36 between the second power storage device 31 and the important loads 38. The switch 41 is provided in the low voltage cable 36 between the first power storage device 30 and the important loads 38.

The LVBMS 15 controls a charging (ie, recharging) of the second power storage device 31 with a current emanating from the ISG 20 and a power supply to the important loads 38 from the second power storage device 31 by the switches 40 and 41 be selectively placed in an on and / or off state. In the vehicle 1 It is a stop / start vehicle equipped with an engine auto-stop feature. This function switches the internal combustion engine 2 during certain operating times automatically, for example when the vehicle 1 is stopped instead of being allowed to get the internal combustion engine 2 idle. If this function is the internal combustion engine 2 LVBMS 15 opens switch 41 with switch 40 closed, thereby disconnecting second power storage device 31 from ISG 20 and connecting second power storage device 31 to the important loads 38 to provide a stable power supply from storage device 31 with a high output power and a high energy density.

When the starter 21 is the internal combustion engine 2 or the ISG 20 starts the combustion engine 2 When the LVBMS 15 restarts, the LVBMS 15 opens the switch 41 with the switch 40 closed, causing the first power storage device 30 to provide power to the starter 21 or the ISG 20. When the switch 41 is open with the switch 40 closed, the first power storage device 30 also provides power to the general loads 37.

As described, the first power storage device 30 provides at least power to the starter 21 and the ISG 20, which are used as starter gears for the internal combustion engine 2 serve. The second power storage device 31 provides at least one power for the general loads 37 and the important loads 38.

The second power storage device 31 is connected to provide power to both the common loads 37 and the important loads 38, however, the LVBMS 15 controls the switches 40 and 41 such that the second power storage device 31 preferably has one Current into the important loads 38 feeds, which constantly require a stable power supply.

Considering the state of charge (SOC) of each of the first and second power storage devices 30 and 31, operating requirements for the general loads 37 and the important loads 38 and the important loads 38 that are required to operate stably The LVBMS 15 sometimes controls the switches 40 and 41 in a manner different from that described above.

The high voltage power pack 34 includes an inverter 45, an INVCM 14, and an HVBMS 16 in addition to the third power storage device 33. The high voltage power pack 34 is connected to the motor generator 4 via the high voltage cable 35 so as to supply power to the motor generator 4 can provide.

Under the control of the INVCM 14, the inverter 45, under certain circumstances, converts an input DC current dissipated from the third power storage device 33 into an output AC current flowing through the high voltage cable 35, and converts in other circumstances, an input alternating current flowing through the high voltage cable 35 into an output direct current, which is fed to the third power storage device 33. The INVCM 14, for example, in response to a current request for operating the motor generator 4 in a power mode, converts a direct current that is discharged from the third power storage device 33 into an alternating current that is input to the motor generator 4.

The INVCM 14 converts an AC power generated by the motor generator 4 into a DC power supplied to the third power storage device 33 in response to a regenerative request for operating the motor generator 4 in a regenerative mode charge.

In the present example, each of the HCU 10, the ECM 11, the TCM 12, the ISGCM 13, the INVCM 14, the LVBMS 15, and the HVBMS 16 consists of a computer unit that has a central processing unit (CPU), a memory random access memory (RAM), read only memory (ROM), flash memory for data backup, input ports and output ports.

The ROMs of these computer units store programs in addition to various constants and various tables to cause each of the computer units to be designated as the corresponding one of the HCU 10, the ECM 11, the TCM 12, the ISGCM 13, the INVCM 14, the LVBMS 15 and the HVBMS 16.

In other words, each of these computer units is caused to function as one of the HCU 10, the ECM 11, the TCM 12, the ISGCM 13, the INVCM 14, the LVBMS 15, and the HVBMS 16, by allowing the CPU executes programs stored in a ROM using a RAM as a work area.

In the present embodiment, the ECM 11 has an engine auto-stop function. This feature automatically shuts off the engine during certain operating times to save fuel. The auto-stop function can be used, for example, when the vehicle 1 is stopped instead of being allowed to get the internal combustion engine 2 idle. The internal combustion engine 2 can be restarted by means of the ISG 20 under the control of the ISGCM 13 when the driver releases the brake or presses the accelerator pedal or accelerator pedal.

The electric hybrid vehicle 1 has CAN communication lines 48 and 49 forming a Local Area Network (LAN) that complies with Controller Area Network (CAN) standards.

The HCU 10 is connected to the INVCM 14 and the HVBMS 16 via the CAN communication line 48. Via this CAN communication line 48, the HCU 10, the INVCM 14 and the HVBMS 16 mutually transmit and receive signals, such as control signals.

The HCU 10 is connected to the ECM 11, the TCM 12, the ISGCM 13, and the LVBMS 15 through the CAN communication line 49. Through this CAN communication line 49, the HCU 10, ECM 11, TCM 12, ISGCM 13, and LVBMS 15 mutually transmit and receive signals, such as control signals.

Referring now to 2 For example, a system 70 for controlling an engine auto-stop includes the ECM 11. The ECM 11 communicates with sensors. The sensors include a brake fluid pressure sensor 51 , a vehicle speed sensor 52 , an accelerator pedal position sensor 53 and a tilt sensor 54 but are not limited to these.

The brake fluid pressure sensor 51 provides the ECM 11 with a pressure (P) signal indicative of brake fluid pressure in a brake system of the hybrid electric vehicle 1 is. The vehicle speed sensor 52 provides for the ECM 11 a vehicle (V) speed signal indicative of the vehicle's vehicle speed 1 is. The accelerator pedal position sensor 53 of an accelerator pedal 53A provides the ECM 11 with an accelerator pedal (AP) position signal that corresponds to a driver's request for a drive.

The tilt sensor 54 provides a GS signal to the ECM 11 indicative of vehicle tilt or incline 1 is. The vehicle 1 includes a lane slope calculator or algorithm (not shown) that determines a lane slope or pavement pitch θ based on the GS signal. The ECM 11, the brake fluid pressure sensor 51 , the vehicle speed sensor 52 , the accelerator pedal position sensor 53 and the tilt sensor 54 in part, form a system 70 for controlling an engine auto-stop.

The ECM 11 acts as the core of an automatic stop-start system 61 that the internal combustion engine 2 automatically shuts off and restarts under certain conditions to reduce fuel consumption. The automatic Stop-start system 61 receives by communication with the brake fluid pressure sensor 51 a current brake fluid pressure, through communication with the vehicle speed sensor 52 a current vehicle speed and by a communication with the tilt sensor 54 an instantaneous road gradient θ. In response to the current brake fluid pressure, the current vehicle speed and the current road grade θ, the automatic stop-start system controls 61 the automatic shutdown of the internal combustion engine 2 ,

The automatic stop-start system 61 can the internal combustion engine 2 stop automatically if specified auto-stop conditions are met or met. Such auto-stop conditions include that the brake fluid pressure P is greater than or equal to a specified pressure, the vehicle speed is less than or equal to a predetermined threshold speed Vth km / h, and the road gradient θ is within a predetermined range, ie, -N ₁ % ≤ θ ≤ + N ₂ %, but are not limited thereto.

In the present embodiment, the engine auto-stop control system 70 outputs based on the outputs (ie, the detected information) of the brake fluid pressure sensor 51 , the vehicle speed sensor 52 , the accelerator pedal position sensor 53 and the tilt sensor 54 but not limited to this, an auto-stop instruction that automatically stops the engine 2 if the given auto-stop conditions are met or met. The system 70 may perform such an auto-stop instruction based on the outputs from other sensors on the motor vehicle 1 output.

When the internal combustion engine 2 is held in the auto-stop state, the internal combustion engine 2 in response to an operator actuate an accelerator pedal 53A, ie, in response to the accelerator pedal position of the accelerator pedal 53A being greater than zero, or in response to an anticipation of the vehicle startup event based on brake release conditions, automatically restarted or restarted started.

The ECM 11 has a malfunction determination section 62 on. The malfunction detection section 62 detects a malfunction in the system 70 if an error occurred in the automatic stop-start system 61 is determined to remain uninterrupted for a first predetermined period of time T1. In the present embodiment, the error shows in the stop-start system 61 the state or refers to this, that the stop-start system 61 no input signals from the brake fluid pressure sensor 51 , the vehicle speed sensor 52 , the accelerator pedal position sensor 53 and the tilt sensor 54 identified.

If such an error in the stop-start system 61 occurs, it is likely that an auto-stop instruction will be issued, indicating the automatic stop of the internal combustion engine 2 not recommended or the internal combustion engine 2 is difficult to restart under the auto-stop condition. Thus, the malfunction detection section represents 62 a malfunction in the stop-start system 61 upon completion of the first predetermined period of time T1, if the error persists uninterrupted for the first predetermined time period T1. In particular, there is a clock that is used to track the error. The timer starts counting up when the error is detected, but stops and resets the elapsed time if the same error is no longer detected. Monitoring the error as to whether the error persists for the first predetermined time period T1 neglects temporal changes in the output of the tilt sensor 54 that can occur in the presence of noise.

There are given auto-stop conditions. The predetermined auto-stop conditions include an autostop condition related to the road grade. If a current lane slope is greater than or equal to a predetermined value, the automatic stop-start system will stop 61 the road-slope-related auto-stop condition after completion or completion of a second predetermined period of time T2 when a current road gradient θ is interrupted within the predetermined range of -N ₁ % ≦ θ ≦ + N over the second predetermined time period T2 ₂ % lies. In particular, there is a timer used for tracking the road grade θ. The timer starts counting up when the lane slope θ is detected to be within the predetermined range, but stops and resets the elapsed time when it is detected that the lane slope θ is no longer within the predetermined range thereof. The second predetermined time period T2 is longer than the first predetermined time period T1, as in FIG 3 shown. In the present embodiment, the automatic stop-start system 61 in response to the predetermined auto stop conditions and the auto stop prevention condition, an auto stop request.

The predetermined value of the road gradient θ is a standard for a Determining whether the automatic stopping of the internal combustion engine 2 causes the motor vehicle 1 emotional. The predetermined value of the road gradient θ is determined so that it is likely that the motor vehicle 1 moves when the internal combustion engine 2 is automatically stopped under the condition of an increased road gradient θ which is equal to or greater than the predetermined value, that is, the motor vehicle 1 stopped on a steep slope or on steep terrain. If a current road grade θ is less than the predetermined value, the vehicle is least likely to be 1 moved, ie the motor vehicle 1 is stopped on a less steep slope or on a flat lane.

The first predetermined period of time T1 is a period of time necessary for a determination of the malfunction in the automatic stop-start system 61 is required. The first predetermined period of time T1 may be referred to as a malfunction determination period. The second predetermined period of time T2 is a period of time required for a determination of the road slope related auto-stop condition. The second predetermined time period T2 may be referred to as a time period for determining the road slope related auto-stop condition. The time t2 when the road slope related auto-stop condition is detected is set at a time later than the time t1 when the malfunction occurs in the automatic stop-start system 61 is detected.

In addition to the second predetermined time period T2 mentioned above, another second predetermined time period T3 is set. This further second predetermined period T3 is a period of time required for a determination of the road slope related auto-stop condition when a current road gradient θ is small and smaller than the predetermined value. This second predetermined time period T3 may be referred to as another time period for determining the road slope related auto-stop condition.

The second predetermined time period T3 is set shorter than the second predetermined time period T2. The time t2 when the road slope related auto-stop condition is detected is set to a time later than the time t3 when the road slope related auto-stop condition is detected.

The automatic stop-start system 61 sets the second predetermined period T2 when a current lane gradient θ is equal to or greater than the predetermined value, but sets the second predetermined period T3 when the current lane slope θ is less than the predetermined value.

In addition, the second predetermined time period T3 is shorter than the first predetermined time period T1. This relationship allows the automatic stop-start system 61 to promptly issue an auto-stop instruction when a current lane gradient θ is less than the predetermined value of the internal combustion engine 2 is, ie when it comes to automatically stopping the internal combustion engine 2 Least likely is that the motor vehicle 1 emotional. This allows increased frequency and prolonged duration of idle reduction to fuel consumption of the internal combustion engine 2 to reduce.

As described, the automatic stop-start system takes 61 depending on the size of a current road gradient θ, a change of the second predetermined time period between T2 and T3.

The malfunction detection section 62 represents a malfunction in the automatic stop-start system 61 after completion of the first predetermined time period T1, if an error in the automatic stop-start system 61 remains over the first predetermined time period T1. If a current lane slope θ is equal to or greater than the predetermined value, the ECM 11 determines the lane slope related auto-stop condition that is one of the predetermined auto-stop conditions after the second predetermined period has ended T2, which is longer than the first predetermined time period T1 when the road slope related auto-stop condition persists for the second predetermined time period T2. The ECM 11 issues an auto-stop prevention instruction when a determination of the malfunction in the automatic stop-start system 61 after completion of the first predetermined time period T1, if the fault is in the automatic stop-start system 61 remains over the first predetermined time period T1. In response to this auto stop prevention instruction, the engine automatically stops 1 prevented.

Referring to 3 For example, the road-slope-related auto-stop condition is shown as an example of the predetermined auto-stop conditions. In addition to the with the road gradient in relation In the auto-stop condition, a brake-stop pressure-related condition and / or a vehicle-speed-related auto-stop condition may be included in the predetermined auto-stop conditions.

Referring to the 4 to 6 A method of controlling an engine stop start is illustrated. In the present embodiment, the in the 4 to 6 described algorithm used.

Referring to 4 a determination is made as to whether in the automatic stop-start system 61 an error is detected or not (at step S1). At step S1, for example, based on the event, the state in which the automatic stop-start system 61 If no input signal identified in the ECM 11 persists for a certain period of time, it is decided that such an error occurs in the automatic stop-start system 61 is present. After a determination of the error, the control proceeds to step S2.

If the determination in step S1 is negative, that is, if the error is in the automatic stop-start system 61 is not detected, control advances to the end of the algorithm labeled "BACK".

At step S2, the elapsed time is counted and stored in a variable T1 _el. The control proceeds to step S3. At step S3, a determination is made as to whether or not the first predetermined time period T1 has ended by comparing the variable T1 _el with the first predetermined time period T1 to determine whether T1 _el = T1 or not. If the determination in step S3 is negative, that is, if the predetermined period of time T1 has not ended, the control advances to the end of the algorithm designated "BACK".

If the error in the automatic stop-start system 61 is continuously detected at step S1, the elapsed time is continuously counted at step S2 until a determination is made that the first predetermined period T1 is completed at step S3. When the determination at step S3 is affirmative, that is, when the first predetermined time period T1 has ended, then control proceeds to step S4. At step S4, the malfunction in the automatic stop-start system becomes 61 detected.

Referring to 5 becomes at step S11 based on the output of the slope sensor 54 a determination is made as to whether or not a current road gradient θ is within the predetermined range -N ₁ % ≦ θ <+ N ₂ %, ie, whether the absolute value of the current road gradient | θ | less than or equal to an auto-stop limit. In the present embodiment, the auto-stop permissible limit value is the absolute value of the upper limit value + N ₂ % of the predetermined range, ie, a predetermined upper road gradient or that of the lower limit value -N _{1 of} the predetermined range, ie a predetermined roadway slope downhill.

If a current lane slope θ is greater than the predetermined lane slope uphill + N ₂ % or less than the predetermined lane slope downhill -N ₁ %, it is likely that the motor vehicle 1 moves when the internal combustion engine 2 is automatically stopped after the motor vehicle 1 has come to a standstill on a slope. Thus, it is preferable to automatically stop the internal combustion engine 2 not to admit. Thus, the limit permitting auto-stop may assume a lane slope selected from a group consisting of such lane slopes as that in which the engine is automatically stopped 2 should be prevented.

If the determination in step S11 is negative, that is, if the automatic stop-start system 61 determines that the current road gradient θ is not within the predetermined range, ie, -N ₁ % ≦ θ ≦ + N ₂ %, or that the absolute value of the current road gradient | θ | is greater than the auto stop limit, then control advances to the end of the algorithm labeled "BACK" without detecting an auto stop condition.

If the determination in step S11 is affirmative, that is, if the automatic stop-start system 61 determines that the current road grade θ is within the predetermined range (-N ₁ % ≤ θ ≤ + N ₂ %) or the absolute value of the current road grade | θ | is less than or equal to the auto-stop permissible limit, then control proceeds to step S12. At step S12, a determination is made as to whether or not the current road gradient θ is equal to or larger than a predetermined value θ _x .

The predetermined value θ _x is a standard for determining whether to automatically stop the internal combustion engine 2 causes the motor vehicle 1 emotional.

When the determination at step S12 is affirmative, that is, when the current road gradient θ is equal to or greater than the predetermined value θ _x , the control proceeds to step S13. When the determination at step S12 is negative, that is, when the current road gradient θ is smaller than the predetermined value θ _x , the control proceeds to step S17.

At step S13, the automatic stop-start system is set 61 determines that a predetermined period T2, which is longer than the first predetermined time period T1, is set as a second predetermined time period T *. At step S17, a predetermined time T3 shorter than the first predetermined time T1 is set as the second predetermined time T *. After step S13 or step S17, the control proceeds to step S14. At step S14, the automatic stop-start system determines 61 in that the elapsed time is counted and stored in a variable T * _el . The control proceeds to step S15. At step S15, a determination is made as to whether or not the second predetermined time period T * (ie, T2 or T3) has ended by comparing the variable T * _el with the second predetermined time period T * to determine whether T * _el = T * is or not.

If the determination in step S15 is negative, i. if the second predetermined period of time T * has not ended, control advances to the end of the algorithm labeled "BACK". If the determination in step S15 is positive, i. if the second predetermined time period T * is completed, then control proceeds to step S16. At step S16, an autostop condition related to the road grade is detected.

Referring to 6 at step S21 in the malfunction determination section 62 made a determination of whether the malfunction in the automatic stop-start system 61 is determined or not. If the determination in step S21 is affirmative, that is, if the malfunction in the road gradient sensor 54 is determined, then the control proceeds to step S22. At step S22, an auto stop prevention request is issued to automatically stop the engine 2 to prevent. After step S22, control advances to the end of the algorithm labeled "BACK".

If the determination in step S21 is negative, that is, if the malfunction in the automatic stop-start system 61 is not determined, then the control proceeds to step S23. At step S23, a determination is made as to whether or not the road-slope related auto-stop condition is detected. If the determination in step S23 is negative, that is, if the road-slope-related auto-stop condition is not detected, the control advances to the end of the algorithm designated "BACK".

If the determination in step S23 is affirmative, that is, if the automatic stop-start system 61 determines that the car-stop condition related to the road slope is detected, the control proceeds to step S24. At step S24, an auto-stop request is issued to automatically stop the engine 2 permit. If other auto-stop conditions apply or are met, the internal combustion engine becomes 2 automatically stopped.

In the present embodiment, the engine auto-stop control system 70 includes the tilt sensor 54 as well as the automatic stop-start system 61 , The automatic stop-start system 61 issues an auto-stop request to automatically stop the internal combustion engine 2 if the given auto-stop conditions are met or met. The predetermined auto-stop conditions include the road slope related auto-stop condition present on the tilt sensor output 54 based.

The system 70 also includes the malfunction detection section 62 , The malfunction detection section 62 represents the malfunction in the automatic stop-start system 61 after completion of the first predetermined time period T1, if the error in the automatic stop-start system 61 remains over the first predetermined time period T1. If a momentary road gradient greater than is the predetermined value or equal to, the system 70 further determines the road slope related auto-stop condition after the second predetermined time period T2 has elapsed, when a current road gradient θ that is within the predetermined range exceeds second predetermined period of time T2 remains, wherein the second predetermined time period T2 is longer than the first predetermined time period T1. The system allows automatic stopping of the internal combustion engine 2 in response to the detected car-stop condition related to the road grade and the detected malfunction.

The malfunction in the automatic stop-start system 61 is detected after completion of the second predetermined period T2. This allows the system 70 to automatically stop the internal combustion engine 2 to prevent when a current lane slope is greater than or equal to the predetermined value when the malfunction in the automatic stop-start system 61 is determined before the determination of the auto-stop condition. This configuration prevents the automatic stop of the internal combustion engine 2 in case of a malfunction in the automatic stop-start system 61 What prevents the motor vehicle 1 moved on a steep slope.

If the malfunction in the automatic stop-start system 61 is not detected before a determination of the road inclination related auto-stop condition, the automatic stopping of the engine 2 allowed when the vehicle is stopped on a steep slope. This improves fuel consumption.

In the present embodiment, the engine auto-stop control system 70 prevents automatic engine stop 2 in response to the detection of the malfunction in the automatic stop-start system 61 , This configuration reliably prevents the motor vehicle 1 moved on a steep slope against the driver's intention.

In the system 70 for controlling an engine auto-stop, the automatic stop-start system selects 61 the predetermined period of time T3, which is shorter than the predetermined time period T2, as the second predetermined period of time, if a current road gradient is less than the predetermined value. This shortens the second predetermined period of time T2 to T3 when the motor vehicle 1 comes to a stop on a roadway having a roadway slope, in which it is least likely that the motor vehicle 1 contrary to the intention of the driver during the automatic stop of the internal combustion engine 2 emotional. The automatic stop-start system 61 immediately stops the automatic engine stop 2 to, that is, after completion of the second predetermined period T3, whereby the fuel consumption is reduced.

Although the disclosure is directed to but not limited to the present embodiment, it will be apparent to those skilled in the art that modifications may be made without departing from the scope of the present invention. All such modifications and equivalents thereof are intended to be covered by the following claims, which are described in the scope of the claims.

LIST OF REFERENCE NUMBERS

1

Motor vehicle (electric hybrid vehicle)

2

internal combustion engine

51

Brake fluid pressure

52

Vehicle speed sensor

54

tilt sensor

61

automatic stop-start system

62

Malfunction determination section

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2012255383 A [0003, 0005]

Claims (3)

A system for controlling an engine auto-stop comprising a lane sensor used to detect a lane slope of a lane surface on which a vehicle is traveling, and an automatic stop-start system configured to control an engine of the vehicle Automatically stop vehicle under any one of predetermined auto-stop conditions including a road slope related auto-stop condition determined on the basis of the detected road slope, characterized by providing a malfunction determination section configured to detect a malfunction in the automatic stop-start system after completion of a first predetermined time period when an error in the automatic stop-start system persists for the first predetermined time period; and the automatic stop-start system, in the case where a current road gradient is equal to or greater than a predetermined value, allows automatic stop of the internal combustion engine after completion of a second predetermined time period longer than the first predetermined time period, when the road slope related, established auto-stop condition persists for the second predetermined time period. System after Claim 1 wherein, in the case where the current road gradient is less than the predetermined value, the automatic stop-start system sets the second predetermined time shorter than the first predetermined time period. System after Claim 1 or 2 wherein the automatic stop-start system prevents the engine from automatically stopping when the malfunction detection section detects the malfunction in the tilt sensor.

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