JP5602525B2 - Coasting control device - Google Patents

Description

  The present invention relates to a coasting control device that disengages a clutch during driving to return the engine to an idle state and suppresses fuel consumption, and the accelerator opening degree can be reduced even for a driver having a large change in accelerator opening degree during coasting control. The present invention relates to a coasting control device capable of performing coasting control equivalent to a driver with a small change width.

  In the vehicle, when the accelerator pedal is depressed when the clutch is disengaged, the accelerator is opened and the engine is so-called empty, and the engine speed settles at the engine speed corresponding to the accelerator opening. At this time, the driving force generated by the engine and the engine internal resistance (friction) are balanced, and the engine output torque is zero. That is, the engine does not work at all with respect to the outside, and fuel is wasted. For example, if the engine speed is 2000 rpm, the driver can hear a loud engine sound, so that a considerable amount of fuel is consumed wastefully.

  The state in which the engine does not work to the outside is not limited to the idling when the clutch is disengaged, but also occurs while the vehicle is running. That is, the engine only rotates at an engine speed corresponding to the accelerator opening, as in the case of flying, and does not contribute to acceleration / deceleration of the vehicle. At this time, fuel is consumed only for rotating the engine, which is very wasteful.

  The present applicant performs coasting control (also referred to as fuel consumption traveling control) that disengages the clutch and returns the engine to an idle state to reduce fuel consumption when the engine is rotating but not working to the outside. A coasting control device was proposed (Patent Document 1).

JP 2006-342832 A JP-A-8-67175 JP 2001-304305 A

  In addition to the above-mentioned proposal, the applicant uses a coasting control determination map using the clutch rotational speed and the accelerator opening as an index, and the plot points of the clutch rotational speed and the accelerator opening are within the coasting controllable region, When the accelerator pedal operation speed is within a predetermined range and the plot point of the clutch rotational speed and the accelerator opening passes the coasting control threshold line in the direction of decreasing the accelerator opening, the clutch is disengaged and the engine rotational speed is decreased. The coasting control device is now proposed to start coasting control and terminate coasting control when the accelerator pedal operation speed is out of a predetermined range or the plot point is out of the coasting controllable region.

  Here, the coasting controllable region is a region formed with a finite width so as to include an engine output torque zero line that is a boundary between a region where the engine output torque is negative and a region where the engine output torque is positive. The coasting control threshold line is set in the vicinity of the engine output torque zero line so as to be substantially along the engine output torque zero line, and is included in the coasting controllable region. Therefore, the plot points of the clutch rotational speed and the accelerator opening first enter the coasting controllable region and pass the coasting control threshold line.

  In general, some drivers have a large change width of the accelerator opening for the same acceleration / deceleration intention, while others have a small change. Here, the change width of the accelerator opening represents an amount by which the accelerator opening is increased or decreased in the operation of depressing or releasing the accelerator pedal. Thus, the change width of the accelerator opening in the accelerator operation varies depending on the driver.

  By the way, coasting control is executed in a state where the intentional accelerator operation is not performed, but even if the intentional accelerator operation is not performed, the accelerator pedal position changes because the foot is on the accelerator pedal. As for the change in the accelerator opening during the coasting control, there are a driver having a large change in the accelerator opening and a driver having a small change.

  When the accelerator opening changes, in the coasting control determination map, the plot point of the clutch rotational speed and the accelerator opening moves in the accelerator opening direction. Compared to the movement width of the plot point when the change amount of the accelerator opening is small and the movement width of the plot point in the accelerator opening direction when the change amount of the accelerator opening is large, the change amount of the accelerator opening is small The movement width of the plot point in the accelerator opening direction is small, and the movement width of the plot point in the accelerator opening direction is large when the change width of the accelerator opening is large.

  Now, if the plot point is in the coasting controllable area and coasting control is being performed, the plot point when the accelerator opening is small is unlikely to go out of the coasting controllable area. The plot points when the accelerator opening change width is large are likely to go out of the coasting controllable region. For this reason, if a driver with a large change in accelerator opening during coasting control is driving, it is easy to get out of the coasting controllable region from the coasting controllable region, and the coasting control time is reduced. The effect of suppressing fuel consumption is insufficient. In addition, such a driver frequently enters the coasting controllable region from outside the coasting controllable region, so that hunting that repeats the start and end of coasting control is likely to occur, which causes discomfort to the driver. There is a fear.

  Therefore, an object of the present invention is to solve the above-described problem and to perform coasting control equivalent to a driver with a small change in accelerator opening even for a driver with a large change in accelerator opening during coasting control. The object is to provide a coasting control device.

  In order to achieve the above object, the present invention relates to a coasting control determination map referred to by the clutch rotational speed and the accelerator opening, and a plot point of the clutch rotational speed and the accelerator opening to the coasting control determination map. In the coasting controllable region formed to include the engine output torque zero line that is a boundary between the region where the engine output torque is positive and the region where the engine output torque is positive, and the accelerator pedal operation speed is within a predetermined range, And when the coasting control threshold line where the plot point of the clutch rotational speed and the accelerator opening is set in the vicinity of the engine output torque zero line passes in the direction of decreasing the accelerator opening, the clutch is disengaged and the engine rotational speed is decreased. Start coasting control and start coasting control when the accelerator pedal operation speed is out of the specified range or the plot point goes out of the coasting controllable area. Learns the coasting control execution section to be completed and the change width of the accelerator opening, and when the change range of the accelerator opening is larger than the area width of the coasting controllable area, the coasting controllable area is expanded and the coasting controllable area width A coasting controllable region adjusting unit that reduces the coasting controllable region when the change amount of the accelerator opening is smaller is provided.

  The coasting controllable area adjusting unit starts learning during coasting control, and extracts a plot point of the clutch rotational speed and the accelerator opening when the change direction of the accelerator opening is reversed as a plot point during inversion. On the coasting control determination map, on the coasting control determination map, on the coasting control determination map, on the coasting control determination map, on the coasting control determination map, on the coasting control determination map A one-side increase / decrease calculation unit for calculating a constant multiple of the difference between the one-side region width, which is the accelerator opening difference from the engine output torque zero line to the coasting controllable region boundary, and the one-side change width, as a one-side increase / decrease amount; An area enlargement / reduction unit that enlarges / reduces the coasting controllable area may be provided by adding the amount to the one-side area width for the entire clutch rotational speed.

  The present invention exhibits the following excellent effects.

  (1) The coasting control can be performed even for a driver having a large change in the accelerator opening during the coasting control, in the same manner as a driver having a small change in the accelerator opening.

It is a block block diagram of the coasting control apparatus of this invention. 1 is a block configuration diagram of a vehicle clutch system to which a coasting control device of the present invention is applied. It is a block diagram of the actuator which implement | achieves the clutch system of FIG. 1 is an input / output configuration diagram of a vehicle to which a coasting control device of the present invention is applied. It is an operation | movement conceptual diagram for demonstrating the outline of coasting control. It is a graph image figure of a coasting control determination map. It is a graph for demonstrating the fuel consumption reduction effect by coasting control. It is a graph of the accelerator opening actually measured in order to create a coasting control determination map, and clutch rotation speed. It is a flowchart which shows the procedure from extraction of the plot point to area expansion / contraction in the coasting control apparatus of this invention. It is the graph which showed the locus | trajectory of the plot point to the coasting control determination map in the coasting control apparatus which does not apply this invention. It is the graph which showed the locus | trajectory of the plot point to the coasting control determination map in the coasting control apparatus to which this invention is applied. It is a graph which shows the time change of the accelerator opening degree during coasting control.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the coasting control device 1 according to the present invention includes a coasting control determination map 2 referred to by the clutch rotational speed and the accelerator opening, and the clutch rotational speed and the accelerator opening to the coasting control determination map 2. The plotted point is within the coasting controllable region formed to include the engine output torque zero line that is the boundary between the region where the engine output torque is negative and the region where the engine output torque is positive. The clutch is disengaged when the speed is within the specified range and the coasting control threshold line in which the plot point of the clutch rotational speed and accelerator opening is set near the engine output torque zero line passes in the direction of decreasing the accelerator opening. At the same time, the coasting control is started by reducing the engine speed, and the accelerator pedal operation speed is out of the predetermined range or the plot point is outside the coasting control possible region. The coasting control execution unit 3 that terminates coasting control when learning, and the variation range of the accelerator opening are learned, and when the variation range of the accelerator opening is larger than the region width of the coasting controllable region, the coasting controllable region is expanded, and the coasting A coasting controllable region adjusting unit 4 is provided that reduces the coasting controllable region when the change width of the accelerator opening is smaller than the region width of the controllable region.

  The coasting controllable area adjustment unit 4 starts learning during coasting control, and extracts the plot point of the clutch rotational speed and the accelerator opening when the change direction of the accelerator opening is reversed as the plot point during inversion. On the plot point extraction unit 5 and the coasting control determination map 2, the difference in accelerator opening from the engine output torque zero line to the plot point at inversion (distance on the horizontal axis in the coasting control determination map 2 in FIG. 6) On the coasting control determination map 2, and the accelerator opening difference from the engine output torque zero line to the coasting controllable region boundary (distance on the horizontal axis in the coasting control determination map 2 in FIG. 6) ) Is a one-side increase / decrease amount calculation unit 7 that calculates a constant multiple of the difference between the one-side region width and the one-side change width as a one-side increase / decrease amount, and this one-side increase / decrease amount is converted into a one-side region width for the entire clutch speed By calculation to, and a region scaling unit 8 scale the coasting control region.

  Coasting control determination map 2, coasting control execution unit 3, coasting controllable region adjustment unit 4, inversion plot point extraction unit 5, one-side change width calculation unit 6, one-side increase / decrease amount calculation unit 7, area constituting coasting control device 1 The expansion / contraction part 8 is preferably mounted on, for example, an electronic control unit (ECU; not shown).

  Each part is demonstrated about the vehicle carrying the coasting control apparatus 1 of this invention.

  As shown in FIG. 2, the vehicle clutch system 101 on which the coasting control device 1 of the present invention is mounted is a system in which a manual type and an automatic type by ECU control are compatible. A clutch master cylinder 103 mechanically coupled to the clutch pedal 102 supplies operating oil to an intermediate cylinder (also referred to as a clutch-free operating cylinder or a switching cylinder) 104 in accordance with a depression / return operation of the clutch pedal 102 by a driver. It is like that. On the other hand, a clutch-free actuator unit 105 controlled by an ECU (not shown) supplies hydraulic oil to the intermediate cylinder 104 in response to a clutch disengagement / contact command. The intermediate cylinder 104 supplies operating oil to the clutch slave cylinder 106. The piston 107 of the clutch slave cylinder 106 is mechanically connected to the movable part of the clutch 108.

  As shown in FIG. 3, the actuator 110 includes a clutch-free actuator 111. The clutch free actuator 111 includes an intermediate cylinder 104 and a clutch free actuator unit 105. The clutch free actuator unit 105 includes a solenoid valve 112, a relief valve 113, and a hydraulic pump 114. In the intermediate cylinder 104, a primary piston 116 and a secondary piston 117 are arranged in series, and when the primary piston 116 is stroked by the operating oil from the clutch master cylinder 103, the secondary piston 117 is stroked with it. . The intermediate cylinder 104 is configured such that the secondary piston 117 is stroked by the operating oil from the clutch-free actuator unit 105. Operating oil is supplied to the clutch slave cylinder 106 in accordance with the stroke of the secondary piston 117. With this configuration, when manual operation is performed, clutch disengagement / engagement is preferentially performed according to manual operation, and when manual operation is not performed, clutch disengagement / engagement according to ECU control is performed.

  The coasting control device 1 of the present invention can also be applied to an automatic clutch system without a manual type.

  As shown in FIG. 4, the vehicle is provided with an ECU 121 that mainly controls a transmission and a clutch, and an ECM 122 that mainly controls an engine. The ECU 121 includes a shift knob switch, a transmission shift sensor, a select sensor, a neutral switch, a T / M rotation sensor, a vehicle speed sensor, an idle switch, a manual changeover switch, a parking brake switch, a door switch, a brake switch, a half-clutch adjustment switch, Input signal lines for the accelerator operation amount sensor, the clutch sensor, and the hydraulic switch are connected. Further, the ECU 121 is connected with output signal lines of a motor of the hydraulic pump 114 of the clutch system 101, a solenoid valve 112, a slope start assisting valve, and a warning & meter. Although not shown, various input signal lines and output signal lines used for engine control are connected to the ECM 122. The ECM 122 can transmit each signal of the engine speed, the accelerator opening, and the engine speed change request to the ECU 121 via a CAN (Controller Area Network) transmission path.

  The clutch rotational speed used in the present invention is the rotational speed on the driven side of the clutch, and is the same as the rotational speed of the input shaft of the transmission. The clutch rotational speed can be obtained from the input shaft rotational speed detected by an input shaft rotational speed sensor (not shown). Alternatively, the clutch rotational speed can be obtained from the vehicle speed detected by the vehicle speed sensor using the gear ratio of the current gear stage. The clutch rotational speed represents the engine rotational speed corresponding to the vehicle speed.

  Hereinafter, the operation of the coasting control device 1 of the present invention will be described.

  The operation concept of coasting control will be described with reference to FIG. The horizontal axis shows time and control flow, and the vertical axis shows engine speed. While the accelerator pedal 141 is largely depressed from the idling state and the accelerator opening degree continues to be 70%, the engine speed 142 increases and the vehicle is accelerated. Assume that a coasting control start condition described later is satisfied when the engine speed 142 is stabilized, the depression of the accelerator pedal 141 is reduced, and the accelerator opening is 35%. By starting coasting control, the clutch is controlled to be disengaged, and the engine speed 142 is controlled to the idle speed. The vehicle will run in coasting control. Thereafter, it is assumed that the accelerator pedal is no longer depressed and the accelerator opening becomes 0% or other coasting control end conditions are satisfied. When the coasting control ends, the engine is controlled to rotate and the clutch is controlled to contact. In this example, since the accelerator opening is 0%, the engine is braked and the vehicle is decelerated.

  If coasting control is not performed, the engine speed remains high as indicated by the broken line during the coasting control execution period, so that fuel is wasted, but coasting control is performed. Thus, during coasting control, the engine speed 142 becomes the idling speed and fuel is saved.

  FIG. 6 shows the coasting control determination map 2 as a graph image.

  The coasting control determination map 2 is a map in which the horizontal axis is the accelerator opening and the vertical axis is the clutch rotational speed. The coasting control determination map 2 can be divided into a minus region MA where the engine output torque is negative and a plus region PA where the engine output torque is positive. The minus region MA is a region where the engine friction is larger than the engine required torque and the engine output torque is negative. The positive region PA is a region where the engine output torque is positive because the engine required torque is larger than the engine friction. The engine output torque zero line ZL, which is the boundary between the minus area MA and the plus area PA, indicates that the engine does not work to the outside as described in the background art, and fuel is wasted.

  In the present embodiment, the coasting control threshold line TL is set slightly to the left of the engine output torque zero line ZL of the coasting control determination map 2 (on the side where the accelerator opening is small). In the coasting control determination map 2, a coasting controllable area CA having a finite width including the coasting control threshold line TL is set between the minus area MA and the plus area PA. In the coasting control determination map 2, a lower limit threshold line UL of the clutch rotational speed is set. The lower limit threshold line UL defines a lower limit threshold value of the clutch rotational speed regardless of the accelerator opening. The lower limit threshold line UL is set slightly above the clutch rotational speed in the idle state as shown in the figure.

The coasting control device 1 starts coasting control when all the following four coasting start conditions are satisfied.
(1) The accelerator pedal operating speed is within the threshold range. (2) In the coasting control determination map 2, the plot points of the clutch rotational speed and the accelerator opening pass the coasting control threshold line TL in the accelerator return direction. The plot point on the control determination map 2 is within the coasting controllable area CA. (4) In the coasting control determination map 2, the clutch rotational speed is greater than or equal to the lower limit threshold line UL

The coasting control device 1 is configured to end coasting control when at least one of the following two coasting termination conditions is satisfied.
(1) The accelerator pedal operating speed is outside the threshold range. (2) The plot point on the coasting control determination map 2 is outside the coasting control possible area CA.

  The operation of the coasting control device 1 according to the coasting control determination map 2, the coasting start condition, and the coasting end condition will be described.

  The coasting control execution unit 3 constantly monitors the accelerator opening based on the accelerator opening and the clutch rotational speed obtained from the input shaft rotational speed or the vehicle speed, and displays the accelerator opening on the coasting control determination map 2 of FIG. Plot the coordinates of the clutch speed. Coordinate points move over time. At this time, when the coordinate point exists in the coasting controllable area CA, the coasting control execution unit 3 determines whether or not to start coasting control. When the coordinate point does not exist in the coasting controllable area CA, the coasting control execution unit 3 does not determine whether to start coasting control.

  Next, when the coordinate point passes the coasting control threshold line TL in the direction in which the accelerator opening decreases, the coasting control execution unit 3 starts coasting control. That is, the coasting control device 1 controls the clutch to be disengaged and controls the control accelerator opening that the ECM 122 instructs the engine to correspond to the idle. As a result, the clutch is disengaged and the engine is in an idle state.

  As shown in FIG. 6 by the arrow indicating the moving direction of the coordinate point, the direction in which the accelerator opening decreases is the left direction in the figure. Even if the coordinate point passes the coasting control threshold line TL, if the movement direction of the coordinate point has a component in the right direction in the figure, the accelerator opening increases, so the coasting control execution unit 3 performs coasting control. Do not start.

  The coasting control execution unit 3 constantly monitors the accelerator opening and the clutch rotational speed even after starting coasting control, and plots the coordinate points of the accelerator opening and the clutch rotational speed on the coasting control determination map 2. When the coordinate point goes out of the coasting controllable area CA, the coasting control execution unit 3 ends the coasting control.

  With the above operation, when the accelerator pedal is operated to the depression side, coasting control is not started even if the coordinate point of the accelerator opening and the clutch rotational speed passes the coasting control threshold line TL, and the accelerator pedal is Since the coasting control is started when the coordinate point passes the coasting control threshold line TL only when operated on the return side, the driver does not feel uncomfortable.

  The coasting control execution unit 3 does not start coasting control when the coordinate point is below the lower limit threshold line UL (the clutch rotational speed is lower than the lower limit threshold). This is because even if the clutch is disengaged when the engine is in an idle state, many effects of suppressing fuel consumption cannot be expected. Therefore, coasting control execution unit 3 starts coasting control only when the coordinate point exists above the lower limit threshold line UL.

  The fuel consumption reduction effect by coasting control will be described with reference to FIG.

  First, it is assumed that coasting control is not performed. The engine speed changes in the range of 1600 to 1700 rpm from about 30 s to about 200 s, and decreases from about 1700 rpm to about 700 rpm (idle speed) between about 200 s and about 260 s. .

  The engine torque increases from about 30 s to about 100 s, but then starts to decrease and continues to decrease to about 150 s. The engine torque is about 0 Nm from about 150 s to about 160 s and increases between about 160 s and about 200 s, but becomes about 0 Nm at about 200 s. As a result, the period during which the engine torque is approximately 0 Nm is from about 150 s to about 160 s (ellipse B1), from about 200 s to about 210 s (ellipse B2), and from about 220 s to about 260 s (ellipse B3). is there.

  The fuel consumption (no vertical axis scale; for convenience, it is arranged so as to overlap with the engine torque) changes from about 50 s to about 200 s almost accompanying the transition of the engine torque. Even if the engine torque is approximately 0 Nm, the fuel consumption is not zero.

  Here, when coasting control is performed, the engine speed is controlled to the idle speed during a period in which the engine torque is approximately 0 Nm. The graph shows a line (thick solid line) of the engine speed during coasting control so as to be separated from a line (solid line) of the engine speed not performing coasting control. The coasting control was executed three times for ellipses B1, B2 and B3. The fuel consumption amount in the period when the coasting control is performed is lower than the fuel consumption amount when the coasting control is not performed, and it is understood that the fuel consumption is saved.

  Next, a specific setting example of the coasting control determination map 2 will be described.

  As shown in FIG. 8, in order to create the coasting control determination map 2, the characteristics of the accelerator opening and the clutch rotational speed are measured, the horizontal axis is the accelerator opening, and the vertical axis is the clutch rotational speed (= engine rotational speed). ; When the clutch is engaged). Thereby, the actually measured engine output torque zero line ZL can be drawn. The entire left side of the engine output torque zero line ZL is the minus region MA, and the entire right side is the plus region PA.

  A coasting control threshold line TL is defined and drawn slightly to the left of the engine output torque zero line ZL. A deceleration zero threshold line TLg is estimated and drawn slightly to the left of the coasting control threshold line TL. An acceleration zero threshold line TLk is estimated and drawn slightly to the right of the engine output torque zero line ZL. A region sandwiched between the deceleration zero threshold line TLg and the acceleration zero threshold line TLk is defined as a coasting controllable region CA. In this example, the lower limit threshold line UL is set to 880 rpm.

  The deceleration zero threshold line TLg and the acceleration zero threshold line TLk are set to such an extent that the driver is difficult to drive. However, since they are problems of human sense, they cannot be quantified by design, so they are tuned with an actual vehicle. The coasting control threshold line TL is set at the center of the deceleration zero threshold line TLg and the acceleration zero threshold line TLk.

  The graph of FIG. 8 created as described above is appropriately digitized (discretized) and written into the storage element, whereby the coasting control determination map 2 that can be used for the arithmetic processing by the coasting control execution unit 3 is obtained.

  Next, operations from extraction of plot points to area expansion / contraction in the coasting control apparatus 1 of the present invention will be described.

  The coasting controllable area adjusting unit 4 repeats the procedure of FIG. 9 at regular intervals.

  In step S901, the inverted plot point extraction unit 5 determines whether the coasting control by the coasting control execution unit 3 is currently being performed. The coasting control being performed means that none of the two coasting end conditions are satisfied after the above-mentioned four coasting start conditions are satisfied. If YES, the coasting control is in progress and the process proceeds to step S902. If NO, the coasting control is not in progress and the process proceeds to step S921.

  In step S902, the inverted plot point extraction unit 5 determines whether a learning flag is set. The learning flag is a flag that is set when the change width of the accelerator opening is learned, and is cleared when the learning is not learned. If YES, the process proceeds to step S904 because the learning is in progress. If NO, the process proceeds to step S903 because the learning is not in progress (the learning has been completed).

  In step S903, the inversion plot point extraction unit 5 sets the learning flag to start learning from the next time because the coasting control is in progress but not learning, and ends. In this way, learning is started when coasting control is started, and the next learning is started when learning is completed during coasting control.

  When the process proceeds to step S904, since learning during coasting control is in progress, the inversion plot point extraction unit 5 determines whether the accelerator opening has changed in the same direction as the previous time. This determination is YES if the accelerator opening continues to increase or continues to decrease, and NO if the accelerator opening changes from increasing to decreasing or decreasing to increasing. However, in order to eliminate the influence of vibration due to vehicle vibration or the like, the accelerator opening signal may be subjected to smoothing processing such as a low-pass filter and a moving average. In the case of YES, the direction of change in the accelerator opening is the same as the previous direction, so the process ends without doing anything. In the case of NO, since the change direction of the accelerator opening is reversed, the process proceeds to step S905.

  In step S905, the reverse plot point extraction unit 5 extracts the current clutch rotation speed and accelerator opening plot points as reverse plot points.

  Next, in step S906, the one-side change width calculation unit 6 calculates the accelerator opening difference (distance on the horizontal axis) from the engine output torque zero line ZL to the inversion plot point on the coasting control determination map 2 as the one-side change width. Calculate as The one side indicates a side where the accelerator opening is large and a small side with respect to the engine output torque zero line ZL, and alternates every time the direction of change of the accelerator opening is reversed.

  Next, in step S907, the one-side increase / decrease amount calculation unit 7 on the coasting control determination map 2 determines the accelerator opening difference (distance on the horizontal axis) from the engine output torque zero line ZL to the one-side boundary of the coasting controllable area CA. A constant multiple of the difference between the one-side area width and the one-side change width is calculated as the one-side increase / decrease amount. The constant may be set in advance based on experiments.

  Next, in step S908, the region expansion / contraction unit 8 adds the one-side increase / decrease amount to the one-side region width for the entire clutch rotational speed, that is, all the locations on the vertical axis, thereby setting the coasting controllable region CA on one side. to shrink. Thus, when the change direction of the accelerator opening is reversed inside the coasting controllable area CA, the one-sided change width of the accelerator opening calculated from the plot point at the time of reversal is smaller than the one-side area width of the coasting controllable area CA. This contributes to the reduction of coasting controllable area CA.

  Next, in step S909, the inverted plot point extraction unit 5 clears the learning flag to indicate that learning has ended, and ends.

  If the determination in step S901 is NO, the coasting control execution unit 3 determines that coasting control is not being performed. This means that after any of the two coasting end conditions described above is satisfied, all four coasting start conditions are not satisfied. In this case, step S921 is executed.

  In step S921, the inverted plot point extraction unit 5 determines whether a learning flag is set. If YES, learning is in progress and the process proceeds to step S922. If NO, learning is not being performed and the process ends without doing anything.

  When the process proceeds to step S922, the learning started during the coasting control is continued even after the coasting control ends, and a search is made for the plot point to be inverted outside the coasting controllable area CA. Thus, in the present invention, learning is continued even after coasting control ends. Note that when coasting control is terminated by the coasting termination condition (1), the driver may intend to accelerate or decelerate, that is, the coasting control may be interrupted, so learning may be terminated. When coasting control is terminated by the coasting termination condition (2), the accelerator opening is increased or decreased without the driver's intention to accelerate or decelerate, so learning is continued.

  In step S922, the inverted plot point extraction unit 5 determines whether or not the accelerator opening has changed in the same direction as the previous time. In the case of YES, the direction of change in the accelerator opening is the same as the previous direction, so the process ends without doing anything. In the case of NO, since the direction of change in the accelerator opening is reversed, the process proceeds to step S923.

  In step S923, the inversion plot point extraction unit 5 extracts the current clutch rotation speed and accelerator opening plot points as inversion plot points.

  Next, in step S924, the one-side change width calculation unit 6 calculates the accelerator opening difference from the engine output torque zero line ZL to the inversion plot point on the coasting control determination map 2 as the one-side change width.

  In step S925, the one-side change width calculation unit 6 determines whether or not the one-side change width is equal to or less than a preset limit value so that the coasting controllable area CA does not increase without limit. In the case of NO, the process proceeds to step S928 to avoid the enlargement of the coasting controllable area CA. If YES, the process proceeds to step S926 to enlarge the coasting controllable area CA.

  In step S926, the one-side increase / decrease amount calculation unit 7 on the coasting control determination map 2, the one-side region width and the one-side variation width that are the accelerator opening difference from the engine output torque zero line ZL to the one-side boundary of the coasting controllable region CA. Is calculated as a one-side increase / decrease amount.

  Next, in step S927, the region expansion / contraction unit 8 expands the coasting controllable region CA to one side by adding this one-side increase / decrease amount to the region width for the entire clutch rotational speed, that is, all the points on the vertical axis. To do. Thus, when the change direction of the accelerator opening is reversed outside the coasting controllable area CA, the one-sided change width of the accelerator opening calculated from the plot point at the time of reversal is larger than the one-side area width of the coasting controllable area CA. Therefore, it contributes to the enlargement of coasting controllable area CA.

  Next, in step S928, the inverted plot point extraction unit 5 clears the learning flag to indicate that learning has ended, and ends.

  The effects of the present invention will be described with reference to FIGS.

  FIG. 10 shows the locus of plot points on the coasting control determination map in the coasting control device to which the present invention is not applied. This is a locus of plot points by a driver whose change in accelerator opening during coasting control is greater than general.

  It is assumed that the plot point PS that is the start of the locus is in coasting control. For the sake of simplicity, it is assumed that the coasting start condition (1) is always satisfied and the coasting end condition (1) is not always satisfied.

  Since the accelerator opening gradually increases from the plot point PS and the plot point comes out to the plus area PA side of the coast controllable area CA, the coast control is terminated by the coast end condition (2). Thereafter, the change in the accelerator opening is reversed and reduced at the plot point P1, and the plot point enters the coasting controllable area CA. Thereafter, when the plot point passes the coasting control threshold line TL in the accelerator return direction, all four coasting start conditions are satisfied, and coasting control is started again. However, since the plot point immediately appears on the minus area MA side of the coasting controllable area CA, the coasting control is terminated by the coasting end condition (2). The change in the accelerator opening is reversed and increased at the plot point P2, the change in the accelerator opening is reversed and decreased at the plot point P3, and the plot point shows the coasting control threshold line TL within the coasting controllable area CA. The coasting control is started three times by passing in the accelerator return direction.

  Thus, when a driver with a large change in accelerator opening during coasting control is operating, the plot point tends to go out of coasting controllable area CA and out of coasting controllable area CA. The running time is reduced, the effect of suppressing fuel consumption becomes insufficient, and the coasting start condition is often satisfied by returning the plot point from the coasting controllable area CA to the coasting controllable area CA. Therefore, hunting that repeats the start and end of coasting control is likely to occur, which may cause driver discomfort.

  On the other hand, the locus | trajectory of the plot point to the coasting control determination map in the coasting control apparatus to which this invention is applied is shown in FIG. The trajectory is the same as that in FIG. In the present invention, plot points P1 to P7 in FIG. 10 are extracted as plot points P1 to P7 at the time of inversion. It is assumed that the coasting controllable area CA has already been expanded by the area expansion / contraction unit 8 of the coasting controllable area adjustment unit 4 than the coasting controllable area CA of FIG. Further, for ease of explanation, it is assumed that the coasting controllable area CA remains the same as in the state of FIG.

  The plot point PS that is the start of the locus is in coasting control. The accelerator opening gradually increases, and the change in the accelerator opening is reversed at the inversion plot point P1 to reduce the accelerator opening. During this time, since the plot point does not go out of the coasting controllable area CA, the coasting control is continued. Thereafter, plot points P2, P3,..., P7 at the time of inversion are extracted, but since these are all within the coasting controllable area CA, the coasting control is continued without being finished once.

  Actually, the coasting controllable area CA expands or contracts whenever a change width of the accelerator opening is newly learned. However, it can be expected that the tendency of the coasting controllable area CA to be large as shown in FIG. 11 is maintained while a driver with a larger change in accelerator opening during coasting control is driving. On the other hand, when a driver with a general change in the accelerator opening during coasting control or a driver with a smaller size starts driving, the coasting controllable area CA is determined by learning the change in the accelerator opening. Reduced. However, the reduction limit may be set so that the coasting controllable area CA is not extremely reduced. Alternatively, it may be prohibited to reduce the coasting controllable area CA at the time of factory shipment.

  Next, the actual state of learning the change width of the accelerator opening will be described.

  As shown in FIG. 12, the accelerator pedal is depressed from the released state to increase the accelerator opening, thereby increasing the clutch rotational speed and accelerating the vehicle. Thereafter, the accelerator pedal is operated in the return direction, and coasting control is started at time t1. Since the accelerator opening at this time t1 is within the coasting controllable area CA at this time t1, coasting control is started. The “region width of the coasting controllable region” in the figure is that when the clutch rotational speed decreases after time t1.

  After that, when the inversion plot points outside the coasting controllable area CA are extracted at the time points t2 and t4, an “accelerator opening change width” wider than the “region width of the coasting controllable area” is obtained. ing. However, the inverted plot point extracted at time t3 is not adopted because the change width of the accelerator opening exceeds the limit. Note that, as described in the procedure, the region width and the change width are obtained separately for each of the larger side and the smaller side of the accelerator opening with reference to the engine output torque zero line ZL.

  As described above, according to the coasting control device 1 of the present invention, the variation range of the accelerator opening is learned, and when the variation range of the accelerator opening is larger than the region width of the coasting controllable region CA, the coasting controllable region CA And the coasting controllable region adjustment unit 4 that reduces the coasting controllable region CA when the change amount of the accelerator opening is smaller than the region width of the coasting controllable region CA. The coasting controllable area CA can be expanded correspondingly to the driving of a driver with a large change width, and the time during which coasting control is performed is prolonged, and hunting that repeatedly starts and ends coasting control is avoided. .

  In this embodiment, the coasting controllable area CA is enlarged and reduced to the plus area PA side and the minus area MA side (the side where the accelerator opening is larger and the side smaller than the output torque zero line ZL). It is also possible to enlarge or reduce only on the side or only on the minus area MA side.

1 coasting control device 2 coasting control determination map 3 coasting control execution unit 4 coasting controllable region adjustment unit 5 inversion plot point extraction unit 6 single side change width calculation unit 7 single side increase / decrease amount calculation unit 8 region expansion / contraction unit

Claims (2)

A coasting control device mounted on a vehicle having a clutch between an engine and a transmission,
Coasting control determination map referred to by clutch rotational speed and accelerator opening,
The plot points of the clutch rotational speed and the accelerator opening on the coasting control determination map are formed so as to include an engine output torque zero line that is a boundary between a region where the engine output torque is negative and a region where the engine output torque is positive. The coasting control threshold line is within the specified coasting controllable region, the accelerator pedal operating speed is within a predetermined range, and the plot points of the clutch rotational speed and the accelerator opening are set near the engine output torque zero line. When passing in the direction of decreasing the accelerator opening, the clutch is disengaged and the engine speed is decreased to start coasting control, and the accelerator pedal operation speed is out of the predetermined range or the plot point is outside the coasting control possible region. Coasting control execution unit that terminates coasting control when exiting,
A coasting controllable region adjustment unit that adjusts the coasting controllable region by performing at least one of enlargement and reduction of the coasting controllable region ;
The coasting controllable region adjusting unit is
Inverted plot point extraction unit that starts learning during coasting control and extracts plot points of clutch rotation speed and accelerator opening when the change direction of the accelerator opening is reversed;
On the coasting control determination map, a one-side change width calculation unit that calculates the accelerator opening difference from the engine output torque zero line to the plot point at inversion as a one-side change width, and
The coasting controllable region adjusting unit is configured to adjust the coasting controllable region only when the one-side change width is equal to or less than a preset limit value . The coasting controllable region adjusting unit is
Before Symbol coasting control determination map on one side increased or decreased for calculating a multiple of the difference between one side region width and said one variation is the accelerator opening difference from the engine output torque zero line to coasting controllable region boundary as one increases or decreases the amount of A quantity calculator;
By adding this one-side increase / decrease amount to the one-side area width for the entire range of the clutch rotation speed, an area expansion / contraction section that expands / reduces the coasting controllable area ,
The coasting controllable area adjustment unit terminates coasting controllable area adjustment when the accelerator pedal operation speed is outside a predetermined range and coasting control ends, and the plot point goes out of the coasting controllable area and coasts. The coasting control device according to claim 1, wherein the coasting control device is configured to continue adjustment of the coasting controllable region when the control is terminated .

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