JP2012132417A - Control device of idle stop vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel economy, by achieving restarting of an optimal engine for preventing the movement of positional dislocation by an idle stop on a slope road.SOLUTION: A road surface slope of a road surface on which an idle stop vehicle 1 travels, is detected based on detection of a vehicle speed detecting sensor and a G sensor 17 of a CVT control part 4, and when the idle stop vehicle 1 stops in a state of stopping an engine 3 by automatically stopping by the establishment of a predetermined engine stopping condition, the movement of the positional dislocation of the idle stop vehicle 1 is measured from a detecting vehicle speed of the CVT control part 4, and the engine 3 is restarted even if the road surface slope is small as the movement of the generated positional dislocation becomes large based on the size of the road surface slope and a degree of the movement by an idle stop control part 11.

Description

  TECHNICAL FIELD The present invention relates to a control device for an idle stop vehicle that automatically stops an engine when a predetermined engine stop condition is satisfied and restarts the engine when a predetermined engine start condition is satisfied. The present invention relates to the movement prevention of misalignment based on the traveling road gradient.

  Conventionally, when the engine is started by an IG (ignition) on operation, the idle stop vehicle executes an idle stop control until the engine is stopped by an IG off operation, and the engine is stopped when a predetermined stop condition is satisfied. It stops automatically and repeats restarting the engine automatically when a predetermined restart condition is satisfied.

  By the way, when this kind of idle stop vehicle stops with the engine stopped due to automatic stop (idle stop state), the braking force depending on the depression of the driver's brake pedal is given to the idle stop vehicle while the vehicle is stopped. Of course, there is an individual difference in the force, and if the stopping time becomes longer, the braking force tends to be weakened.

  The strength of the braking force is not so much a problem on flat roads, but if the idle stop vehicle stops when the engine is stopped automatically (idle stop state) while traveling on an up (or down) slope road, the road surface gradient and Depending on the level of the braking force, a so-called sliding position shift may occur when the vehicle is stopped (during idle stop), which may give the driver a sense of discomfort.

  Therefore, on slope roads (slopes), by the hill hold control, the brake fluid pressure immediately before the engine stops due to automatic stop is maintained while the vehicle is stopped (during idle stop). (See, for example, Patent Document 1 (paragraphs [0046]-[0047], [0062]-[0066], FIG. 1)).

JP 2006-131121 A

  Even if the hill hold control is performed, if the slope is steep or the braking force immediately before the engine stops is insufficient, the idle stop vehicle stops with the engine stopped (idle stop) due to automatic stop. Then, not only the position shift due to the sliding down may occur against the intention of the driver (user), but also a driver may feel uncomfortable.

  In order to prevent the above unintended misalignment movement, if such movement occurs during idle stop on a slope, the engine is restarted and moved regardless of whether or not the restart condition is satisfied. It is possible to prevent it.

  However, for example, on an uphill slope road, if the engine is restarted if a slight slippage is detected during idle stop, the effect of noise (disturbance) will not occur even though the engine has not actually slipped down. Therefore, there is a problem that the engine is unnecessarily detected and the engine is unnecessarily started against the intention of the driver (user) based on the erroneous detection. On the other hand, if the detection error of the slippage during idle stop is lowered and the engine is restarted only when a large slippage of a certain level or more is detected to eliminate the false detection described above, the slippage may occur even in a steep slope. Since the engine is not restarted until a detectable amount of movement is caused by the descent, there is a possibility that the engine will be delayed due to a steep decline and the driver may feel uncomfortable.

  Then, if there is a possibility that the displacement of the position due to the above-described slippage may occur on the slope road, the driver disables the idle stop control and does not use it, so that the fuel consumption decreases.

  SUMMARY OF THE INVENTION An object of the present invention is to realize an optimal engine restart that prevents displacement due to an idle stop on a slope road and to improve fuel efficiency.

  In order to achieve the above object, an idle stop vehicle control device according to the present invention automatically stops an engine when a predetermined engine stop condition is satisfied, and restarts the engine when a predetermined engine start condition is satisfied. A slope detecting means for detecting a road slope, a movement measuring means for measuring a movement of a position shift of an idle stop vehicle while the engine is stopped by the automatic stop, and the slope detection. Control means for restarting the engine regardless of whether or not the engine start condition is satisfied, based on the magnitude of the road gradient detected by the means and the degree of movement measured by the movement measuring means. (Claim 1).

  In the control apparatus for an idle stop vehicle according to the present invention, a plurality of the movement measuring means are provided, and the control means needs to restart the engine as the road surface gradient detected by each of the gradient detecting means increases. The engine is restarted even if the number of movement measuring means for measuring movement is small (claim 2).

  According to the first aspect of the present invention, when the vehicle is stopped in a state where the engine is stopped by the automatic stop on the gradient road, the control means not only determines the degree of displacement displacement measured by the movement measurement means but also the gradient detection means. In consideration of the magnitude of the road surface gradient detected by the engine, the engine is restarted regardless of whether or not the engine start condition is satisfied. Therefore, during idle stop on a slope road, the detected road surface gradient becomes larger and steeper, so that the engine can be restarted even if the displacement movement is small, and the generated displacement movement is less likely to occur. The larger the value, the more reliably the engine can be restarted even when the road surface gradient is small. Therefore, it is possible to reliably prevent the movement of the positional deviation from both the magnitude of the road surface gradient and the degree of the movement of the positional deviation, and to perform an optimal engine restart that does not give the driver a sense of incongruity. Can be realized.

  As a result, the driver does not invalidate the idle stop control, and the fuel efficiency of the idle stop vehicle can be improved.

  According to the invention of claim 2, a plurality of movement measuring means are provided, and even if the measurement is varied due to road surface conditions during idle stop, when the road surface gradient detected by the gradient detecting means becomes large and steep, The control means restarts the engine even if the number of movement measuring means for measuring the movement that requires engine restart is small. Therefore, the engine restart is not possible during idle stop on a steep road with a large road gradient. When the necessary displacement occurs, the engine can be restarted more reliably, the engine can be restarted more optimally, and the fuel consumption of the idle stop vehicle can be further improved. .

It is a block diagram of one embodiment of a control device of an idle stop car of the present invention. It is explanatory drawing of the vehicle speed example which restarts the engine with respect to the road surface gradient of the control apparatus of FIG. It is a block diagram of other embodiment of the control apparatus of the idle stop vehicle of this invention. It is explanatory drawing of the vehicle speed which restarts the engine with respect to the road surface gradient of the control apparatus of FIG.

  Next, in order to describe the present invention in more detail, an embodiment of the present invention will be described in detail with reference to FIGS.

(One embodiment)
With reference to FIGS. 1 and 2, an embodiment corresponding to claim 1 will be described.

  FIG. 1 shows a block configuration of a control device of the present embodiment of an idle stop vehicle 1a. The idle stop vehicle 1a is a single lead battery having a relatively small capacity of 12V as a power source in order to reduce weight, size, and the like. 2 is used as a power source. The negative terminal of the lead battery 2 is connected to the casing of the idle stop vehicle 1a.

  In FIG. 1, 3 is an engine of the idle stop vehicle 1 a, 4 is a CVT on the transmission side of the engine 3, and a torque converter (including a lock-up clutch mechanism) 5 is interposed between the engine 3 and the engine 3. The CVT control unit 4 has vehicle speed detection means for detecting the vehicle speed of the idle stop vehicle 1a from the rotational speed, and outputs the detected vehicle speed Vcvt on the CVT side to the CVT control unit 14 described later.

  Reference numeral 6 denotes a starter for starting the engine 3, and power is supplied from the lead battery 2 through the relay 7. A battery sensor 8 is provided close to the lead battery 2 between the positive terminal of the lead battery 2 and the relay 7, and detects the temperature, current, and voltage of the lead battery 2. Reference numeral 9 denotes an alternator to which the rotational force of the engine 3 is transmitted via the belt 10 and charges the lead battery 2 with a power generation output during traveling.

  11 is an idle stop control unit formed by an idle stop control ECU, 12 is an engine control unit formed by an engine control ECU, 13 is an ABS control unit formed by an ABS (antilocked breaking system) control ECU, and 14 is CVT control. This is a CVT control unit formed by the ECU. Each of the control units 11 to 14 is formed by a microcomputer or the like, and exchanges information via a communication bus 15 such as CAN.

  Reference numeral 16 denotes a display unit formed by a dashboard combination meter, which receives various display data from the communication bus 15.

  Reference numeral 17 denotes a G sensor of the idle stop vehicle 1 a connected to the idle stop control unit 11. Reference numeral 18 denotes a wheel speed sensor that provides the ABS control unit 13 with a detected vehicle speed Vwss on the wheel side, and is actually provided for each of the four front, rear, left and right wheels. A hydraulic pressure sensor 19 gives the ABS control unit 13 detection information of the master cylinder pressure of the brake mechanism.

  The schematic control and operation of the idle stop vehicle 1a will be described. When the driver turns on an IG key (not shown) to instruct the engine start, an IG on signal is sent from the communication bus 15, for example, to idle stop. Based on this input, the idle stop control unit 11 is turned on by instantaneously energizing the relay 7, the power of the lead battery 2 is supplied to the starter 6, and the starter 6 is started and stopped. The engine 3 is started (first start). Once the engine 3 is started and the lead battery 2 is once fully charged with the power generated by the alternator 9, the idle stop control unit 11 is then idle stopped until the engine 3 is stopped by turning off the IG key. Execute control.

  The idle stop control unit 11 includes information such as the engine speed and cooling water temperature of the engine control unit 12, information on the temperature, current, and voltage of the lead battery 2, ABS control via the communication bus 15 and a dedicated line. Information of the detected vehicle speed Vwss and master cylinder pressure of the unit 13, lock-up clutch information of the CVT control unit 14, detected vehicle speed Vcvt of the CVT control unit 4 via the CVT control unit 14, detection information of the G sensor 17, and stop not shown Information on switches in various parts of the vehicle such as lamp switches and courtesy switches is input.

  Based on this information, the idle stop control unit 11 detects that the driver depresses the brake pedal according to a red signal of the traffic signal and the like and the master cylinder pressure is equal to or higher than a predetermined depressing pressure. By confirming that a predetermined stop condition for control (for example, a condition where the stop lamp is lit and the vehicle speed is equal to or less than the predetermined vehicle speed) is satisfied, the engine can be reduced if the vehicle speed falls below the predetermined vehicle speed even if the vehicle does not stop completely. The controller 12 is instructed to stop the engine. In response to this command, the engine control unit 12 throttles the fuel throttle and automatically stops the engine 3, whereby the idle stop vehicle 1a is stopped (idle stop) with the engine stopped due to automatic stop.

  Next, when the driver releases his / her foot from the brake pedal and the master cylinder pressure is reduced to a predetermined release pressure because the traffic signal changes to a green light during the idle stop, the idle stop control unit 11 When the vehicle 1a confirms that a predetermined restart condition for idle stop control (for example, a condition that the stop lamp is turned off and the door is closed) is established, the relay 7 is turned on by instantaneously energizing the lead battery. The power source 2 is supplied to the starter 6 to start the starter 6, and the stopped engine 3 is automatically restarted.

  Thereafter, automatic stop of the engine 3 based on establishment of a predetermined stop condition during deceleration and automatic restart of the engine 3 based on establishment of a predetermined restart condition are alternately performed.

  By the way, for example, when the engine is automatically stopped by idle stop control on an uphill slope road, if the shift of the position shift occurs and the idle stop vehicle 1a slides down, not only does the driver (user) feel uneasy, There is a possibility of actually colliding with the following car.

  And when the movement of the positional deviation occurs, based on the detection, it is conceivable that the idle stop control unit 11 restarts the engine regardless of whether or not the engine start condition is satisfied to prevent the sliding, As described above, depending on the detection of the movement of the positional deviation, a situation may occur in which it is erroneously detected that it has slipped down easily due to the influence of noise (disturbance) even though it has not actually slipped down. In addition to the possibility of slippage due to erroneous detection at the slope, there is a possibility that the restart of the engine with respect to the slippage at the steep slope is delayed, which makes the driver feel uncomfortable. This also occurs during idle stops on downhill slopes.

  Therefore, in the present embodiment, it is determined whether or not the engine 3 is to be restarted during idle stop in consideration of both the magnitude of the road surface gradient and the degree of displacement.

  The G sensor 17 and the vehicle speed detecting means of the CVT control unit 4 form the gradient detecting means of the present invention, the vehicle speed detecting means of the CVT control unit 4 forms the movement measuring means of the present invention, and the idle stop control unit 11 The control means of the present invention is formed.

  The gradient detection means formed by the G sensor 17 and the vehicle speed detection means of the CVT control unit 4 is configured such that the detected acceleration / deceleration (hereinafter referred to as G sensor value) of the G sensor 17 depends on the acceleration / deceleration component based on the road surface gradient and the change in the vehicle speed. Therefore, the acceleration / deceleration component based on the change in the vehicle speed is detected from the time change (time differentiation) of the detected vehicle speed Vcvt on the CVT side. Then, the acceleration / deceleration component based on the G sensor value and the time change (time differentiation) of the detected vehicle speed Vcvt taken into the idle stop control unit 11 by the idle stop control unit 11 via the CVT control unit 14 and the communication bus 15. The road slope (gradient slope) is obtained from the difference from the value of.

  In the case of the present embodiment, the shift of the position shift of the idle stop vehicle 1a during the idle stop is detected and measured from the vehicle speed of the idle stop vehicle 1a, and the vehicle speed detection means of the CVT control unit 4 forms. The movement measuring means measures the absolute value (detected vehicle speed | Vcvt |) of the detected vehicle speed Vcvt as the displacement amount of the position shift of the idle stop vehicle 1a.

  The control unit formed by the idle stop control unit 11 is configured to determine an engine start condition based on the magnitude of the road surface gradient detected by the gradient detection unit and the detected vehicle speed | Vcvt | measured by the movement measurement unit during the idle stop. The engine 3 is restarted regardless of whether it is established.

  During the idle stop, the combination of the road surface gradient and the detected vehicle speed | Vcvt | which may cause the idle stop vehicle 1 to slide down and the engine 3 needs to be restarted is detected in advance by simulation, experiment, etc. The dimensional map data is held in the idle stop control unit 11.

  FIG. 2 shows the characteristics of the engine restart vehicle speed (minimum vehicle speed at which the engine 3 needs to be restarted) with respect to the road surface gradient of one example of the map data. The vehicle speed at which the engine 3 needs to be restarted becomes smaller as it becomes larger (steeper).

  The control unit needs to restart the engine 3 from the map data based on the road surface gradient detected by the gradient detection unit and the detected vehicle speed | Vcvt | measured by the movement measurement unit during idle stop. When a vehicle speed equal to or higher than a certain vehicle speed is detected, the relay 7 is turned on by instantaneously energizing regardless of whether or not a predetermined restart condition is satisfied, the power of the lead battery 2 is supplied to the starter 6, and the starter 6 is started. The stopped engine 3 is automatically restarted.

  Therefore, in the case of the present embodiment, the engine 3 is detected even when the displacement (detected vehicle speed | Vcvt |) is smaller as the detected road gradient becomes larger and steep during idling stop on the uphill and downhill roads. The engine 3 can be reliably restarted even when the road surface gradient is small, as the generated displacement (detected vehicle speed | Vcvt |) increases. Therefore, it is possible to reliably prevent the movement of the positional deviation from both the magnitude of the road surface gradient and the degree of the movement of the positional deviation, and it is possible to optimally restart the engine 3 that does not give the driver a sense of incongruity. Can be realized.

  As a result, the driver does not invalidate the idle stop control, and the fuel efficiency of the idle stop vehicle 1a can be improved.

(Other embodiments)
With reference to FIG. 3 and FIG. 4, another embodiment corresponding to claim 2 will be described.

  FIG. 3 shows a block configuration of the control device of the present embodiment of the idle stop vehicle 1b. In FIG. 3, the same reference numerals as those in FIG. 1 denote the same or corresponding components.

  The difference between the idle stop vehicle 1b and the idle stop vehicle 1a is that (1) wheel speed sensors 18a, 18b provided by the movement measuring means of the present invention are respectively provided on a total of four tires on the front, rear, left and right of the idle stop vehicle 1b. 18c and 18d, and the shift of the position shift of the idle stop vehicle 1b is detected in place of the detected vehicle speed | Vcvt |. The detected vehicle speed Vwss on the wheel side of the four wheel speed sensors 18a, 18b, 18c and 18d. (2) The control means of the idle stop control unit 11 is a movement that requires the engine to be restarted as the road surface gradient detected by the gradient detection means becomes larger (the detected vehicle speed | Vwss |). The engine 3 is restarted even if the number of wheel speed sensors 18a to 18d for measuring the vehicle speed is small.

  That is, in the case of this embodiment, the idle stop vehicle 1 is provided with a plurality of the movement measuring means by the wheel speed sensors 18a to 18d, and the detected vehicle speed | Vwss | of each of the wheel speed sensors 18a to 18d is set as the value of the idle stop vehicle 1b. The amount of movement of the downward displacement is taken from the ABS control unit 13 to the idle stop control unit 11 via the communication bus 15.

  At this time, the vehicle speed | Vwss | detected by the wheel speed sensors 18a to 18d may vary depending on the road surface condition.

  Then, the control means of the idle stop control unit 11 monitors the detected vehicle speed | Vwss | of the wheel speed sensors 18a to 18d, and the detected vehicle speed | which exceeds the vehicle speed at which the engine 3 needs to be restarted | Even if the number of wheel speed sensors 18a to 18d that output Vwss | is small, the engine 3 is restarted, and the measurement of the vehicle speed | Vwss | detected by the wheel speed sensors 18a to 18d varies depending on the road surface condition during idle stop. However, the delay in restarting the engine 3 with respect to the steep slope is prevented more reliably.

  FIG. 4 shows a portion of the upward gradient road having the characteristic shown in FIG. 2. In the case of the present embodiment, the idle stop vehicle 1 may slide down during the idle stop of the upward gradient road, and the engine 3 is restarted. The combination of the road surface gradient and the vehicle speed that needs to be adjusted is flat (gradient slope 0%) to climbing a% (gradient slope a%), climbing a% to climbing b% (gradient slope b%), climbing b% to climbing It is divided into 4 parts, c% (gradient slope c%) and uphill c%.

  When the slope is flat (gradient slope 0%) to climbing slope a%, the detected vehicle speeds | Vwss | of all four wheel speed sensors 18a to 18d are equal to or higher than a predetermined value α (for example, 2.0 km / h), and the climbing slope a% to When the gradient is uphill b%, the vehicle speed | Vwss | detected by the wheel speed sensors 18a to 18d of all four wheels is a predetermined value β (for example, 1.5 km / h) or more, and when the gradient is uphill b% to uphill c%, the wheel speed sensor 18a. Wheel speed sensors 18a to 18d when the vehicle speed | Vwss | of any two (for example, two on the front side or the rear side) is higher than a predetermined value γ (for example, 1.0 km / h) and the slope is c% or higher. If the detected vehicle speed | Vwss | is equal to or higher than a predetermined value γ (for example, 0.5 km / h), the engine 3 is restarted.

  It should be noted that the engine 3 is restarted by dividing into the same sections also on the down slope road.

  Therefore, in the case of the idle stop vehicle 1b of the present embodiment, a plurality of wheel speed sensors 18a to 18d of the movement measuring means are provided, and even if the measurement varies due to road surface conditions during the idle stop, the gradient detecting means. When the road surface gradient detected by the engine is greatly steep, even if the number of wheel speed sensors 18a to 18d for measuring the movement (vehicle speed) that requires restarting the engine 3 is small, the control means restarts the engine 3, and further The engine 3 can be reliably restarted, the engine can be restarted more optimally, and the fuel consumption of the idle stop vehicle 1b can be further improved.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. Of course, it may be performed during idle stop on one of the slopes.

  Of course, it is possible to detect the movement of the position shift of the idle stop vehicles 1a and 1b during the idle stop from other than the vehicle speed.

  Furthermore, the characteristics of the map data held in the idle stop control unit 11 are different depending on the structure of the idle stop vehicle and the like, and may be different from those shown in FIGS.

  Next, in the one embodiment, instead of the detected vehicle speed | Vcvt |, one of the detected vehicle speeds | Vwss | of the four wheel speed sensors 18a, 18b, 18c, and 18d of the other embodiments or an average value is used. Alternatively, the display vehicle speed output from the ABS control unit 13 to the communication bus 15 based on the detected vehicle speed Vwss of the wheel speed sensors 18a, 18b, 18c, and 18d may be used.

  In the other embodiments, the range and number of combinations of road surface gradients and vehicle speeds that require the engine 3 to be restarted may be appropriately set based on experiments or the like. The number of wheel speed sensors 18a to 18d that detect a vehicle speed that is higher than the vehicle speed that needs to be restarted may be set appropriately based on experiments or the like.

  The present invention can be applied to various idle stop vehicle control devices.

1a, 1b Idle stop vehicle 3 Engine 11 Idle stop control unit

Claims (2)

A control device for an idle stop vehicle that automatically stops an engine when a predetermined engine stop condition is satisfied, and restarts the engine when a predetermined engine start condition is satisfied,
A slope detecting means for detecting a road surface slope;
A movement measuring means for measuring the movement of the position shift of the idle stop vehicle while the engine is stopped with the automatic stop;
Control means for restarting the engine regardless of whether or not the engine start condition is satisfied based on the magnitude of the road surface gradient detected by the gradient detecting means and the degree of movement measured by the movement measuring means. A control device for an idle stop vehicle. In the control apparatus of the idle stop vehicle according to claim 1,
A plurality of the movement measuring means are provided,
The control means restarts the engine even if the number of movement measuring means for measuring the movement that requires restarting the engine is small as the road surface gradient detected by the gradient detecting means increases. Car control device.

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