JP2008267186A - Control device in shifting of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a shift shock caused by erroneous determination of a target gear position, when performing rotation synchronous control in shifting of a manual transmission. <P>SOLUTION: The rotation synchronous control is prohibited by determining that a target engine speed tNe set in response to a second speed is higher by a predetermined value ΔN or more than a transmission input shaft rotating speed Nt detected when gear fastening is fixed (illustrated (a)), when erroneously determining that a target gear position predicted in response to detection of a shift lever position is the second seed, when a shift lever is shifted down to a fourth speed from a fifth speed. Thus, an engine speed NE is reduced, and the engine speed when fastening a clutch can be approached to the transmission input shaft rotating speed Nt being an original target engine speed, and a thrusting-up (acceleration) shock can be restrained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device at the time of shifting in a vehicle (MT vehicle) including a manual transmission connected to an output side of an engine via a clutch.

In Patent Document 1, in a manual transmission that shifts by operating a shift lever in a select direction for selecting a gear position and a stroke direction for fastening a gear, a select direction operation before the shift lever reaches a specific gear position is disclosed. By predicting the gear position inside, calculating the transmission input shaft rotational speed corresponding to the predicted gear position as the target engine rotational speed, and performing feedback control so that the engine rotational speed is synchronized with the target engine rotational speed, A technique for calculating a shift shock while shortening the shift time is described.
JP 2007-32341 A

  By the way, when the driver performs a shift operation by applying an excessive load when performing the above-described rotation synchronous control of the manual transmission, the output of the select direction sensor is different from the actual output due to the torsion of the lever rod or the like. There is a possibility that the signal corresponding to the gear position is output, and the predicted gear position is shifted from the actual gear position.

  As a result, there is a concern that the engine rotation speed is controlled to an incorrect target engine rotation speed, and a large shift shock occurs when the clutch is engaged.

  The above problem can also occur when the select direction sensor fails.

  The present invention has been made paying attention to such a conventional problem, and aims to reduce the shift shock to a minimum by relaxing as much as possible by a malfunction of control that occurs when the gear position is predicted incorrectly. To do.

For this reason, the present invention
In a vehicle where a manual transmission is connected to the engine via a clutch,
Gear position prediction means for predicting the gear position after the shift at the time of a shift operation in which the release of the clutch is detected;
A rotation synchronization control means for feedback-controlling the engine rotation speed with the input shaft rotation speed of the transmission at the predicted gear position as a target engine rotation speed;
Gear engagement detection means for detecting gear engagement of the manual transmission;
A transmission input shaft rotation speed detecting means for detecting an input shaft rotation speed of the transmission when the gear engagement is detected;
Engine deceleration control means for decelerating the engine rotational speed when the target engine rotational speed is larger than the detected input shaft rotational speed of the transmission by a predetermined rotational speed or more;
It is characterized by having

  In this way, when the gear position at the time of the shift operation is erroneously predicted and the target engine speed is greater than the transmission input speed at the actual gear position by a predetermined value or more, the engine speed is reduced. Therefore, the shift shock at the time of clutch engagement can be mitigated.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a system diagram of an MT vehicle showing an embodiment of the present invention.

  An engine (internal combustion engine) 1 mounted on a vehicle is provided with an electrically controlled throttle valve 3 for controlling an intake air amount in an intake passage 2 thereof, and an opening degree thereof is controlled by an engine control unit (ECU) 4. Although illustration and description of the fuel supply system of the engine 1 are omitted, the supplied fuel amount is controlled by the ECU 4 so that a desired air-fuel ratio is obtained with respect to the intake air amount.

A manual transmission 6 is connected to the output side of the engine 1 via a clutch 5. The clutch 5 is released / fastened by the driver's clutch pedal operation, and is released when the driver steps on the clutch 5. The gear position of the manual transmission can be switched by a driver's shift lever (shift knob) operation.
Signals are input to the ECU 4 from various sensors.

  The accelerator pedal sensor 11 detects the depression amount (accelerator opening) APO of the accelerator pedal and outputs a corresponding signal.

  The crank angle sensor 12 outputs a signal synchronized with the rotation of the crankshaft of the engine 1, and can detect the engine speed NE from this signal.

  The vehicle speed sensor 13 detects the vehicle speed (output shaft rotational speed of the transmission 6) VSP and outputs a corresponding signal.

  The clutch pedal switch 14 outputs an ON / OFF signal corresponding to the position of the clutch pedal, and is turned on when the clutch is released (when the clutch pedal is depressed).

  The shift position sensor 15 outputs a signal corresponding to the position of the shift lever (shift knob). Specifically, the shift position sensor 15A outputs a signal corresponding to the position in the x direction (select direction) in FIG. It is composed of a stroke position sensor 15B that outputs a signal corresponding to the direction (stroke direction) position, and the gear position (including the target gear position during shifting and the determination of gear engagement) can be determined by the signal output of these two direction positions. It is.

  The neutral switch 16 is turned on when the shift lever is in the neutral region (see FIG. 4).

  Further, a rotation synchronization control permission switch 17 is provided at the driver's seat or the like for selecting permission or prohibition of rotation synchronization control at the time of shifting according to preference, and an ON (permission) / OFF (prohibition) signal is also input to the ECU 4. Has been.

  Further, an Nt sensor 18 for detecting the input shaft rotational speed Nt of the transmission 6 is provided, and the Nt signal is also input to the ECU 4.

  Here, the ECU 4 determines the driver request torque based on the accelerator opening APO (and the engine speed Ne), and normally (during non-shifting), the target engine torque tTe = driver request torque. Based on the target engine torque tTe (and the engine speed Ne), a target throttle opening tTVO for obtaining this is calculated, and the opening of the electric throttle valve 3 is controlled according to the target throttle opening tTVO.

  On the other hand, at the time of shifting, rotation synchronization control is performed in calculating the target engine torque tTe on condition that the rotation synchronization control permission switch 17 is ON.

  Here, in the present invention, when the target gear position is erroneously predicted and, as a result, the calculated target engine rotational speed is too large and a shift shock occurs, rotation synchronization including fail-safe control for decelerating the engine is performed. Take control.

  Below, the rotation synchronous control at the time of the shift by ECU4 is demonstrated with the flowchart of FIG. 2, FIG.

  FIG. 2 is a flowchart of a rotation synchronization control flag setting routine, which is executed every predetermined time.

  In step S1, it is determined whether or not the rotation synchronization control permission switch is ON. If it is OFF, the process proceeds to step S2, and the rotation synchronization control flag F = 0 and the rotation synchronization control is prohibited.

  If the rotation synchronization control permission switch is ON, the process proceeds to step S3, and it is determined whether or not the rotation synchronization control flag F = 1 (during rotation synchronization control).

  If the rotation synchronization control flag F = 0 and rotation synchronization control is not being performed, the process proceeds to step S4.

  In step S4, it is determined whether or not the clutch pedal switch is ON (clutch disengagement). If the clutch pedal switch is OFF (clutch engagement), the process proceeds to step S2, and the rotation synchronization control flag F = 0 is set and rotation synchronization is performed. End control. If the clutch pedal switch is ON (clutch release), the process proceeds to step S5.

  In step S5, it is determined whether the target gear position has changed based on the signal from the shift position sensor. For example, referring to FIG. 2, an example of a downshift from the 3rd speed to the 2nd speed will be described. When a shift from the 3rd speed to the neutral state is reached by the history of signals from the shift position sensor, the target position is reached. It is determined that the gear position has changed from the third speed to the second speed (the target gear position after the shift is the second speed).

  Here, in order to ensure the effect of shifting shock reduction by the rotation synchronization control, the target gear position is estimated as soon as possible and the start of the rotation synchronization control is accelerated, and the engine rotation speed is changed to the target engine rotation speed described later. It is required to converge. For this reason, the determination position is set to a position during the select direction operation.

  If no change in the target gear position is recognized, this routine is terminated.

  When the change of the target gear position is recognized, the process proceeds to step S6, and the rotation synchronization control flag F = 1 is set in the state where the target gear position after the shift is specified, and the rotation synchronization control is started.

  Here, the flowchart of the rotation synchronization control routine of FIG. 3 will be described. This routine is also executed every predetermined time.

  In step S21, it is determined whether or not the rotation synchronization control flag F = 1. If F = 0, the process proceeds to step S22 to perform normal engine torque control.

  When the rotation synchronization control flag F = 1, the process proceeds to step S23, where the target gear position after the shift is determined from the target gear position (gear ratio GR) after the shift and the current vehicle speed (transmission output shaft rotation speed) VSP. A target engine rotational speed tNE (= VSP / GR) that is balanced with the vehicle speed necessary for traveling is calculated.

Next, in step S24, the actual engine speed NE is detected.
Next, in step S25, the actual engine speed NE is compared with the target engine speed tNE.

  If NE <tNE as a result of the comparison, the process proceeds to step S26, where the target engine torque tTe is increased to increase the throttle opening TVO and increase the engine speed NE to approach the target engine speed tNE. .

  On the other hand, if NE> tNE, the process proceeds to step S27, where the target engine torque tTe is decreased to decrease the throttle opening TVO and decrease the engine speed NE to approach the target engine speed tNE.

  Returning to the flowchart of FIG.

  After the rotation synchronization control flag F = 1 and the rotation synchronization control is started, the process proceeds to step S7 by the determination in step S2.

  In step S7, it is determined whether or not gear engagement is confirmed. The confirmation of gear engagement may be before completion of gear engagement to the gear position after the shift, but at least the gears mesh and the input shaft of the transmission is in a state of rotating in synchronization with the output shaft. In this embodiment, the determination is made based on the output of the shift position sensor. For example, referring to FIG. 4, a description will be given of an example of downshift from the 3rd speed to the 2nd speed. When the signal output of the shift position sensor falls within a predetermined range (x2, y2) corresponding to the 2nd speed position, the gear is engaged. It is determined to be fixed. Alternatively, when a sensor that directly detects the gear position is provided, the gear engagement may be determined based on the detection value of the sensor.

  When the gear engagement is confirmed, the process proceeds to step S8, and the transmission input shaft rotational speed Nt is calculated based on the signal from the Nt sensor 18. If the Nt sensor 18 is not provided, Nt = VSP / GR can be calculated from the determined gear position GR and the vehicle speed (transmission output shaft rotational speed) VSP.

  Next, in step S9, it is determined whether or not the target engine speed tNE calculated from the target gear position is larger than the current transmission input shaft speed Nt by a predetermined value ΔN or more.

  If it is determined that it is less than the predetermined value ΔN, this routine is ended and the rotation synchronization control is continued as it is. However, if it is determined that it is greater than the predetermined value ΔN (tNE−Nt ≧ ΔN), step S10 is performed. Then, the rotation synchronization control flag F = 0 is set, and the rotation synchronization control is prohibited (terminated).

  As described above, when the driver performs a shift operation with an excessive load, the output of the select direction sensor outputs a signal corresponding to the gear position different from the actual due to torsion of the rod of the lever, etc. When a change in the target gear position is detected in step S5, the changed target gear position may be erroneously determined. Alternatively, there may be a case where, during a shift operation, after a gear position to be shifted is selected and a different gear position is determined as a target gear position, a reverse operation is performed in the reverse direction. Further, the target gear position may be erroneously determined due to a failure of the shift position sensor (select position sensor) or other abnormality.

  The target engine rotational speed at the original correct target gear position is set to coincide with the transmission input shaft rotational speed Nt after the gear engagement is confirmed, but if the target gear position is erroneously determined to the low speed side, The target engine rotational speed set based on the erroneously determined target gear position is set to be larger than the original target engine rotational speed, that is, the transmission input shaft rotational speed Nt after the gear engagement is confirmed.

  Therefore, when the target gear position is erroneously determined to be low, and the target engine rotational speed tNE is greater than the transmission input shaft rotational speed Nt detected after the gear engagement is confirmed, the rotational synchronization control is performed. If it continues as it is, the engine rotation speed becomes too high, so that the rotation synchronization control is terminated.

  As a result, the engine 1 switches to control for maintaining normal idle rotation, and is quickly decelerated, and the engine rotation speed NE is brought close to the transmission input shaft rotation speed Nt. Shock can be suppressed.

  FIG. 5 shows changes in various state quantities when the target gear position is erroneously determined to be the second gear when downshifting from the fifth gear to the fourth gear.

  When the target engine rotational speed tNE is larger than the transmission input shaft rotational speed Nt detected when the gear engagement shown in FIG. A is confirmed by a predetermined value ΔN or more, the rotational synchronization control flag F is set to 0 and the rotational synchronization control is ended.

  As a result, since the current engine speed NE is too high with respect to the normal target idle speed, the required torque becomes negative (fuel cut) and the speed is quickly reduced. When the clutch is engaged, the rotation synchronization control is continued. In addition, the rotational speed difference and shock shown in FIG.

  In the above embodiment, by prohibiting the rotation synchronization control when the target engine rotation speed is too high, the engine rotation speed NE can be decelerated with good response. However, when the clutch release time is too long, the engine rotation speed is set when the clutch is engaged. NE may be too low.

  Therefore, as a second embodiment, the target engine rotation speed of the rotation synchronization control may be switched to the transmission input shaft rotation speed Nt detected when the gear engagement is confirmed.

  FIG. 6 shows a flowchart of the second embodiment. When it is determined in step S10 ′ that the target engine speed tNE is larger than the transmission input shaft speed Nt by a predetermined value ΔN or more, the target engine speed tNE is set. The transmission input shaft rotation speed Nt calculated in step S8 is switched.

  In the first embodiment, the engine speed can be reduced as quickly as possible to minimize the increase with respect to the original target engine speed when the clutch is engaged. On the other hand, according to the second embodiment, Compared to the first embodiment, the degree of engine deceleration is low, but it is possible to prevent a shock due to the engine speed being too low when the clutch is engaged.

  In the above-described embodiment, the target gear position for rotational synchronization control is predicted based on the shift lever position. However, the present invention can be applied to a method for predicting by other methods. For example, if the gear position before shifting is at the slowest speed side or the fastest speed side and the clutch is released, the next gear position is predicted and rotation synchronous control is started. The target engine rotation speed may become too large by predicting the gear position, etc., so that the same effect can be obtained by applying the present invention.

1 is an MT vehicle system diagram showing an embodiment of the present invention. Flowchart of rotation synchronization control flag setting routine Flow chart of rotation synchronization control routine Illustration of shift position sensor output The time chart which shows the change of various state quantity in one control example in the same embodiment Flowchart of rotation synchronization control flag setting routine in the second embodiment

Explanation of symbols

1 Engine 2 Air intake passage 3 Electric throttle valve 4 ECU
DESCRIPTION OF SYMBOLS 5 Clutch 6 Manual transmission 11 Accelerator pedal sensor 12 Crank angle sensor 13 Vehicle speed sensor 14 Clutch pedal sensor 15 Shift position sensor 16 Neutral switch 17 Rotation synchronous control permission switch

Claims (6)

In a vehicle where a manual transmission is connected to the engine via a clutch,
Gear position prediction means for predicting the gear position after the shift at the time of a shift operation in which the release of the clutch is detected;
A rotation synchronization control means for feedback-controlling the engine rotation speed with the input shaft rotation speed of the transmission at the predicted gear position as a target engine rotation speed;
Gear engagement detection means for detecting gear engagement of the manual transmission;
A transmission input shaft rotation speed detecting means for detecting an input shaft rotation speed of the transmission when the gear engagement is detected;
Engine deceleration control means for decelerating the engine rotational speed when the target engine rotational speed is larger than the detected input shaft rotational speed of the transmission by a predetermined rotational speed or more;
A control device for shifting a vehicle characterized by comprising: Means for detecting a position of a shift lever for shifting the manual transmission;
The control device for shifting a vehicle according to claim 1, wherein the gear position predicting means predicts a gear position after shifting based on a detection position during shifting operation of the shift lever.   The control device for shifting a vehicle according to claim 1 or 2, wherein the engine deceleration control means inhibits the rotation synchronization control and decelerates the engine rotation speed.   The engine deceleration control means switches the target rotational speed in the rotational synchronization control to the detected actual input shaft rotational speed of the transmission to decelerate the engine rotational speed. The control apparatus at the time of the shift of the vehicle as described in 2. Means for detecting a position of a shift lever for shifting the manual transmission;
The gear engagement detection means detects gear engagement when the shift lever moves to a position close to a gear position after completion of the shift operation. The control apparatus at the time of the shift of the vehicle as described in 2. 5. The vehicle gear shift control according to claim 1, wherein the gear engagement detection unit detects gear engagement based on a detection value of a sensor that directly detects a gear position. 6. apparatus.

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