JP5546988B2 - Coasting control device - Google Patents

Description

  The present invention relates to a coasting control device capable of improving ride comfort and reducing driver discomfort.

  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.

  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. At this time, the engine simply rotates at an engine speed corresponding to the accelerator opening degree as in the case of flying, and does not contribute to acceleration / deceleration of the vehicle. Therefore, fuel is consumed only for rotating the engine, which is very wasteful.

  The present applicant has proposed a coasting control device that performs coasting control that reduces fuel consumption by disengaging the clutch and returning the engine to an idle state when the engine is rotating but does not work to the outside ( Patent Document 2).

  In coasting control, in a vehicle equipped with a mechanism that can automatically connect and disconnect the clutch, when the engine is rotating but does not work to the outside, the clutch is automatically disconnected and the engine speed is set to the idling speed or equivalent. This is a technique to improve fuel efficiency by setting the number of revolutions.

  The coasting control can be applied to any vehicle that can automatically turn off the engine output (automatically engage / disengage the clutch) as described above. Therefore, the coasting control is not limited to a manual clutch system (manual T / M), The same effect can be obtained also in other clutch systems (ordinary torque converter AT and AMT).

JP-A-8-67175 JP 2006-342832 A

  However, in Patent Document 2, the clutch may be disengaged even when the driver depresses the accelerator with the intention of accelerating, and the driver feels torque loss when shifting from deceleration to acceleration, and feels uncomfortable. is there.

  Therefore, the present applicant creates a coasting control determination map using the accelerator opening and the clutch rotational speed as indices, and on this coasting control determination map, the coasting where the coordinate points of the accelerator opening and the clutch rotational speed are set in advance. A coasting control device is being proposed that starts coasting control when the control threshold line passes in the direction in which the accelerator opening decreases.

  In this coasting control device, when the coasting control end condition that the coordinate point of the accelerator opening and the clutch rotational speed has gone out of the coasting control possible area set on the coasting control determination map is satisfied, coasting control is performed. To be finished.

  Also, in the coasting control device, if the accelerator pedal operation speed falls outside the threshold range or the driver steps on the clutch, the coasting control prohibition condition is satisfied and the coasting control is terminated regardless of the coasting control end condition. To be finished.

  However, when the coasting control end condition is not satisfied, and only the coasting control prohibition condition is satisfied and coasting control ends, that is, the coasting control on the coasting control determination map is possible with the coordinate points of the accelerator opening and the clutch rotational speed. When the coasting control is terminated by the operation speed of the accelerator pedal or the operation of the clutch within the region, the coasting control is performed again if the condition for starting the coasting control is satisfied even after the coasting control ends. Therefore, for example, in a situation where the driver is running with the foot on the clutch and the clutch is repeatedly turned ON / OFF due to the vibration of the vehicle, the coasting control is repeatedly started / finished and hunting is repeated. There is a possibility of waking up. In this case, the ride comfort becomes worse and the driver may feel uncomfortable.

  Therefore, an object of the present invention is to provide a coasting control device that can solve the above-described problems, improve riding comfort, and reduce driver discomfort.

  The present invention was devised to achieve the above object, and when the engine does not work to the outside during running, the clutch is disengaged and the coasting control reduces the engine speed to the idle speed. In the coasting control device, the accelerator opening and the clutch rotational speed are used as indices, and along the engine output torque zero line that is the boundary between the negative region where the engine output torque is negative and the positive region where the engine output torque is positive A coasting control determination map in which a coasting control threshold line is set and a coasting controllable region having a finite width including the coasting control threshold line is set between the minus region and the plus region, and the coasting control When the coordinate point of the accelerator opening and the clutch rotational speed on the judgment map passes the coasting control threshold line in the direction in which the accelerator opening decreases, the coasting control Start coasting control when the coasting control end condition that the coordinate point of the accelerator opening and the clutch rotational speed goes out of the coasting controllable region is satisfied, or when the predetermined coasting control prohibition condition is satisfied A coasting control execution determining unit that terminates the coasting operation, turning off the coasting permission flag during coasting control, and turning on the coasting permission flag when the coasting control termination condition is satisfied while coasting control is not being performed. The coasting control flag control unit is a coasting control device configured to start coasting control only when the coasting permission flag is on.

  The coasting control execution determination unit may be configured not to start coasting control when the coasting control prohibition condition is satisfied.

  The coasting control execution determination unit determines that the coasting control prohibition condition is satisfied when the operation speed of the accelerator pedal is out of a preset threshold range or the clutch is depressed, and terminates coasting control. It may be made like.

  ADVANTAGE OF THE INVENTION According to this invention, the coasting control apparatus which can improve riding comfort and can reduce a driver's discomfort can be provided.

1 is an input / output configuration diagram of a vehicle to which a coasting control device of the present invention is applied. 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. In this invention, it is an operation | movement conceptual diagram for demonstrating the outline | summary of coasting control. In this invention, it is a graph image figure of a coasting control determination map. In this invention, it is a graph for demonstrating the fuel consumption reduction effect by coasting control. In this invention, it is a figure of the coasting control determination map in which coasting control was actually performed. In this invention, it is a flowchart explaining the control flow of a coasting permission flag control part. In this invention, it is a figure explaining operation | movement of a coasting permission flag control part. It is a flowchart explaining the control flow of the coasting control apparatus of this invention.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an input / output configuration diagram of a vehicle to which a coasting control device according to the present embodiment is applied.

  As shown in FIG. 1, the vehicle is provided with an electronic control unit 11 that mainly controls a transmission and a clutch, and an ECM (engine control module) 12 that mainly controls an engine.

  The electronic control unit 11 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, and a half clutch. The input signal lines of the adjustment switch, clutch sensor, and hydraulic switch are connected. The electronic control unit 11 is connected to the motor and solenoid valve 62 of the hydraulic pump 64 of the clutch system 51, the slope start assisting valve, and the output signal lines of the warning & meter.

  Although not shown, various input signal lines and output signal lines used for engine control are connected to the ECM 12. The ECM 12 can transmit each signal of the engine speed, the accelerator opening, and the engine rotation change request to the electronic control unit 11 via a CAN (Controller Area Network) transmission path.

  Here, a vehicle clutch system will be described.

  As shown in FIG. 2, the vehicle clutch system 51 is a system that is compatible with a manual type and an automatic type controlled by the electronic control unit 11. A clutch master cylinder 53 mechanically coupled to the clutch pedal 52 supplies operating oil to the clutch-free operating cylinder 54. On the other hand, the clutch free actuator unit 55 controlled by the electronic control unit 11 also supplies operating oil to the clutch free operating cylinder 54. The clutch free operating cylinder 54 supplies operating oil to the clutch slave cylinder 56. The piston 57 of the clutch slave cylinder 56 is mechanically connected to the movable part of the clutch 58.

  As shown in FIG. 3, the clutch free actuator 65 includes an intermediate cylinder 61 that is the clutch free operating cylinder 54 of FIG. 2, a solenoid valve 62 that constitutes the clutch free actuator unit 55, a relief valve 63, and a hydraulic pump 64. In the intermediate cylinder 61, a primary piston 66 and a secondary piston 67 are arranged in series, and when the primary piston 66 is stroked by the operating oil from the clutch master cylinder 53, the secondary piston 67 is caused to stroke. . Further, the secondary piston 67 is stroked by the operating oil from the clutch-free actuator unit 55. Operating oil is supplied to the clutch slave cylinder 56 in accordance with the stroke of the secondary piston 67. 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 is performed as controlled by the electronic control unit 11. The

  Here, the manual and automatic clutch systems have been described, but an automatic clutch system (ATM) may be used.

  Next, the coasting control apparatus according to the present embodiment will be described.

  The vehicle has a coasting control device 1 that performs coasting control in which the clutch is disengaged and the engine rotational speed is reduced to the idle rotational speed (or the corresponding rotational speed) when the engine does not work outside while traveling. Is installed.

  First, the operation concept of coasting control will be described with reference to FIG. In FIG. 4, the horizontal axis indicates time and the flow of control, and the vertical axis indicates the engine speed.

  As shown in FIG. 4, while the accelerator pedal 71 is largely depressed and the state where the accelerator opening degree is 70% continues, the engine speed 72 increases and the vehicle is accelerated. Assume that the coasting control start condition described later is satisfied when the engine speed 72 is stabilized, the depression of the accelerator pedal 71 is reduced, and the accelerator opening is 35%. By starting coasting control, the clutch is controlled to be disengaged, and the engine speed 72 is controlled to the idle speed. Thereafter, it is assumed that the accelerator pedal 71 is not depressed and the accelerator opening becomes 0% or other coasting control termination 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, the engine speed 72 becomes the idle speed and fuel is saved.

  Returning to FIG. 1, the coasting control device 1 digitally samples the output signal of the accelerator opening sensor every predetermined time, and detects the accelerator opening that uses the moving average value as the accelerator opening every predetermined time. When the accelerator opening speed is calculated by differentiating the part 2 and the accelerator opening for a predetermined time, and the accelerator opening speed is negative and the absolute value is smaller than a preset start reference value A determination condition detection unit 3 that permits determination of coasting control start, and a boundary between a negative region in which the engine output torque is negative and a positive region in which the engine output torque is positive, using the accelerator opening and the clutch rotational speed as indices. The coasting control determination map 4 in which the coasting control threshold line is set along the engine output torque zero line (no load line) and the coasting control start determination are permitted. A coasting control execution determination unit 5 that starts coasting control when a coordinate point between the accelerator opening and the clutch rotational speed passes the coasting control threshold line in a direction in which the accelerator opening decreases on the determination map 4 is provided. Yes.

  Here, the clutch rotational speed 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. In the present embodiment, a clutch rotational speed sensor is provided on the input shaft, and the clutch rotational speed is detected from the rotational speed of the input shaft.

  The accelerator opening detection unit 2, the determination condition detection unit 3, the coasting control determination map 4, and the coasting control execution determination unit 5 are preferably mounted on the electronic control unit 11.

  FIG. 5 shows the coasting control determination map 4 as a graph image.

  The coasting control determination map 4 is created by measuring in advance the correlation between the accelerator opening and the clutch rotational speed for the engine in a clutch disengaged state.

  As shown in FIG. 5, the coasting control determination map 4 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 4 can be divided into a minus region M where the engine output torque is negative and a plus region P where the engine output torque is positive. That is, the minus region M is a region where the engine friction is larger than the engine required torque and the engine output torque is negative. The positive region P is a region where the engine output torque is positive because the engine required torque is larger than the engine friction. An engine output torque zero line (no-load line) Z that is a boundary between the minus region M and the plus region P indicates that the engine does not work to the outside and fuel is wasted.

  In this embodiment, the coasting control threshold line T is set slightly to the left of the engine output torque zero line Z of the coasting control determination map 4 (on the side where the accelerator opening is small).

  In the coasting control determination map 4, a coasting controllable area CA having a finite width including the coasting control threshold line T is set between the minus area M and the plus area P.

  In the coasting control determination map 4, a lower limit threshold line U of the clutch rotational speed is set. The lower limit threshold line U defines the lower limit threshold value of the clutch rotational speed regardless of the accelerator opening. The lower limit threshold line U is set slightly higher than the clutch rotational speed in the idle state as shown in the figure.

The coasting control device 1 starts coasting control when all of the following six coasting control start conditions are satisfied.
(1) The accelerator pedal operation speed is within the threshold range. (2) The coasting control determination map 4 passes the coasting control threshold line T in the accelerator return direction. (3) The plot point on the coasting control determination map 4 is coasting control. Within the possible area CA (4) In the coasting control determination map 4, the clutch rotational speed is equal to or greater than the lower limit threshold line U.

Furthermore, in the present embodiment, coasting control device 1 starts coasting control when the following two conditions are satisfied in addition to the above four coasting control start conditions.
(5) The coasting permission flag is on. (6) The coasting control prohibition condition is not satisfied.

  The coasting permission flag is turned on / off by a coasting permission flag control unit 6 described later. When the coasting permission flag is on, the coasting control is permitted to start, and when the coasting permission flag is off, the coasting control is not permitted to start. .

Further, the coasting control device 1 is configured to end coasting control when the next coasting control end condition is satisfied.
(1) The plot point on the coasting control determination map 4 is outside the coasting controllable area CA

Furthermore, the coasting control device 1 ends coasting control when either of the following two coasting control prohibition conditions is satisfied.
(1) The accelerator pedal operating speed is outside the threshold range. (2) The clutch is depressed.

  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 approximately 0 Nm at three locations 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).

  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.

  If coasting control is performed here, the engine speed is controlled to the idle speed during a period in which the engine torque is approximately 0 Nm. The graph shows the engine speed line during thick coasting control (thick solid line) so as to be separated from the engine rotational speed line without solid coasting control (solid line). 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.

  FIG. 7 shows a coasting control determination map 100 in which coasting control is actually performed. Each point shows a plot point of the actually detected accelerator opening and clutch rotational speed. In the coasting control determination map 100, a negative region, a positive region, a coasting control threshold line (acceleration 0 threshold point, deceleration 0 threshold point), and a coasting controllable region are set.

  Now, coasting control apparatus 1 according to the present embodiment turns coasting permission flag off during coasting control, and coasting permission flag that turns coasting permission flag on when coasting control end condition is satisfied while coasting control is not being performed. A flag control unit 6 is provided.

  The coasting permission flag control unit 6 is mounted on the electronic control unit 11 similarly to the accelerator opening detection unit 2, the determination condition detection unit 3, the coasting control determination map 4, and the coasting control execution determination unit 5. The coasting permission flag control unit 6 may be mounted on a unit other than the electronic control unit 11 (for example, the ECM 12), and the accelerator opening detection unit 2, the determination condition detection unit 3, the coasting control determination map 4, It may be mounted on a unit different from the unit on which the coasting control execution determination unit 5 is mounted.

  A control flow in the coasting permission flag control unit 6 will be described with reference to FIG.

  As shown in FIG. 8, the coasting permission flag control unit 6 first determines whether coasting control is being performed (step S1).

  If it is determined in step S1 that the coasting control is being performed (YES), the coasting permission flag control unit 6 turns off the coasting permission flag (step S2) and ends the process.

  If it is determined in step S1 that the coasting control is not being performed (NO), the coasting permission flag control unit 6 determines whether the coasting control end condition is satisfied (step S3).

  If it is determined in step S3 that the coasting control end condition is satisfied (YES), the coasting permission flag control unit 6 turns on the coasting permission flag (step S4) and ends the process. If it is determined in step S3 that the coasting control end condition is not satisfied (NO), the coasting permission flag control unit 6 does not change the coasting permission flag and ends the process as it is.

  That is, the coasting permission flag control unit 6 turns the coasting permission flag off during coasting control, does not perform coasting control, and coasts when the coordinates of the accelerator opening and the clutch rotational speed are within the coasting controllable area CA. If the permission flag is not maintained and the coasting control is not being performed, and the coordinate point of the accelerator opening and the clutch rotational speed is outside the coasting controllable area CA, the coasting permission flag is turned on.

  Thus, when the accelerator opening and the coordinate point of the clutch rotational speed are in the coasting controllable area CA and coasting control is terminated by the operation speed of the accelerator pedal or the clutch operation (coasting control prohibition condition), the accelerator opening While the coordinate point of the clutch rotational speed is within the coasting controllable area CA, the coasting permission flag is kept off, and when the accelerator opening degree and the coordinate point of the clutch rotational speed are out of the coasting controllable area CA, The coasting permission flag is turned on.

  More specifically, if the coasting control prohibition condition is established at point A in FIG. 9 and coasting control is terminated, when the coordinate point of the accelerator opening and the clutch rotational speed transitions from point A to point B, The coordinate point of the accelerator opening and the clutch rotational speed is in the coasting controllable area CA, and the coasting control end condition is not satisfied, so the coasting permission flag remains off. Therefore, even if the coasting control prohibition condition is not satisfied at the point B and the coasting control start condition is satisfied, the coasting control is not started.

  On the other hand, in FIG. 9, when the coordinate point of the accelerator opening and the clutch rotational speed transitions from the point A to the C point, the coordinate point of the accelerator opening and the clutch rotational speed goes out of the coasting controllable area CA. The coasting control end condition is satisfied, and the coasting permission flag is turned on.

  That is, according to the coasting control device 1, after coasting control is finished, the coasting permission flag is not turned on unless the coordinate points of the accelerator opening and the clutch rotational speed are once out of the coasting controllable area CA. The coasting control will not be performed.

  A control flow of coasting control apparatus 1 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 10, the coasting control execution determination unit 5 first determines whether coasting control is being performed (step S11).

  If it is determined in step S11 that coasting control is being performed (YES), coasting control execution determination unit 5 determines whether coasting control end conditions are not satisfied (step S12), and coasting control end conditions in step S12. Is determined to be not satisfied (NO), coasting control is terminated (step S14), and the process is terminated.

  If it is determined in step S12 that the coasting control end condition is not satisfied (YES), coasting control execution determination unit 5 determines whether the coasting control prohibition condition is not satisfied (step S13), and coasting in step S13. If it is determined that the control prohibition condition is not satisfied (NO), coasting control is terminated (step S14), and the process is terminated. If it is determined in step S13 that the coasting control prohibition condition is not satisfied (YES), the coasting control is terminated without terminating coasting control, and coasting control is continued.

  On the other hand, if it is determined in step S11 that coasting control is not being performed (NO), coasting control execution determination unit 5 determines whether coasting control start conditions are satisfied (step S15), and coasting control start conditions in step S15. If NO is determined (NO), the process is terminated without starting coasting control.

  If it is determined in step S15 that the coasting control start condition is satisfied (YES), coasting control execution determination unit 5 determines whether the coasting control prohibition condition is not satisfied (step S16), and coasting control is performed in step S16. If it is determined that the prohibition condition is not satisfied (NO), the process is terminated without starting coasting control.

  If it is determined in step S16 that the coasting control prohibition condition is not satisfied (YES), coasting control execution determination unit 5 determines whether the coasting permission flag is on (step S17), and coasting permission is performed in step S17. If it is determined that the flag is not on (NO), the process is terminated without starting coasting control. If it is determined in step S17 that the coasting permission flag is ON (YES), coasting control execution determination unit 5 starts coasting control (step S18) and ends the process.

  As described above, coasting control apparatus 1 according to the present embodiment turns coasting permission flag off during coasting control, and turns coasting permission flag on when coasting control end conditions are satisfied while coasting control is not being performed. The coasting permission flag control unit 6 is configured such that the coasting control execution determination unit 5 starts coasting control only when the coasting permission flag is on.

  As a result, when coasting control is terminated under conditions other than coasting control termination conditions (coasting control prohibition conditions), the coasting permission flag is set as long as the coordinate points of the accelerator opening and the clutch rotational speed do not go out of coasting controllable area CA once. Is kept off, and the next coasting control is not performed.

  Therefore, for example, even when the driver is traveling with the foot on the clutch and the clutch is repeatedly turned ON / OFF due to the vibration of the vehicle, the start / end of coasting control is repeated. There is no risk of hunting. Therefore, according to the coasting control device 1, it is possible to improve ride comfort and reduce driver discomfort.

  Further, in the coasting control device 1, the coasting control execution determination unit 5 is configured not to start coasting control when the coasting control prohibition condition is satisfied. As a result, for example, the coasting control start condition is satisfied while the clutch is being depressed, and the coasting control is terminated due to the coasting control prohibition condition immediately after the coasting control is started.

1 coasting control device 2 accelerator opening detection unit 3 determination condition detection unit 4 coasting control determination map 5 coasting control execution determination unit 6 coasting permission flag control unit

Claims (3)

In the coasting control device that performs coasting control to disengage the clutch and reduce the engine speed to the idle speed when the engine does not work to the outside during traveling,
Using the accelerator opening and the clutch rotational speed, which is the rotational speed on the driven side of the clutch, as an index, the engine output torque zero line is the boundary between the negative region where the engine output torque is negative and the positive region where the engine output torque is positive. A coasting control determination map in which a coasting control threshold line is set along, and a coasting controllable region having a finite width including the coasting control threshold line is set between the minus region and the plus region, and
On the coasting control determination map, when the coordinate point of the accelerator opening and the clutch rotational speed passes the coasting control threshold line in the direction in which the accelerator opening decreases, coasting control is started, and the accelerator opening and A coasting control execution determination unit that terminates coasting control when a coasting control end condition that the coordinate point of the clutch rotational speed has gone out of the coasting controllable region is satisfied, or when a predetermined coasting control prohibition condition is satisfied; With
And the coasting permission flag control unit that turns off the coasting permission flag during coasting control, turns on the coasting permission flag when the coasting control end condition is satisfied and is not coasting control,
The coasting control apparatus is characterized in that the coasting control execution determination unit starts coasting control only when a coasting permission flag is on.   The coasting control device according to claim 1, wherein the coasting control execution determination unit is configured not to start coasting control when the coasting control prohibition condition is satisfied.   The coasting control execution determination unit determines that the coasting control prohibition condition is satisfied when the operation speed of the accelerator pedal is out of a preset threshold range or the clutch is depressed, and terminates coasting control. The coasting control device according to claim 1 or 2, wherein the coasting control device is configured as described above.

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