JP2006275118A - Control unit of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control unit of an automatic transmission capable of restraining a deterioration in speed changeability and a speed change delay. <P>SOLUTION: In the control unit of an automatic transmission, hydraulic pressure to a frictional connection device of the automatic transmission, which is necessary for maintaining a speed change gear after changing speed at a terminating stage of speed change of the automatic transmission, is kept lower than the hydraulic pressure based on line hydraulic pressure (S60). The hydraulic pressure to the frictional connection device is arranged between the hydraulic pressure necessary for maintaining connecting conditions of the frictional connection device necessary for maintaining the speed change gear and the line hydraulic pressure (S60). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for an automatic transmission.

  Multi-stage automatic transmission is progressing. Therefore, especially when the vehicle starts with the accelerator opening being an intermediate opening (partial opening), even if the amount of change (increase) in the vehicle speed is relatively small, In many cases, the next shift must be performed in a short time after the end of the shift.

  Japanese Patent Laid-Open No. 2000-145937 (Patent Document 1) discloses a technique for performing downshift control according to road conditions based on road information stored in a navigation system.

JP 2000-145937 A

It is desired that the next shift operation is performed in a short period with little delay from the previous shift operation.
In addition, when performing deceleration control by downshifting the transmission, the vehicle travels in a state in which the vehicle behavior is likely to be affected, for example, when vehicle turning determination or tire slip determination is performed. It is preferable to control the vehicle so as not to impair the stability of the vehicle. In this case, if a state in which the vehicle behavior is likely to be affected after the downshift is detected is detected from the detection time. It is desired that control for ensuring the stability of the vehicle be performed in a short period of time.

An object of the present invention is to provide a control device for an automatic transmission capable of suppressing deterioration of shift characteristics and shift delay.
Another object of the present invention is that when the deceleration control is performed by downshifting the transmission, the vehicle behavior is affected when the vehicle turning judgment or tire slip judgment is performed after the downshift. Another object of the present invention is to provide an automatic transmission control device capable of performing control for ensuring the stability of a vehicle in a state where there is little delay from the time of detection when an easy state is detected.

  The control device for an automatic transmission according to the present invention is a control device for an automatic transmission, wherein the automatic transmission required to maintain the gear position after the gear shift at the end of the gear shift of the automatic transmission. The hydraulic pressure to the frictional engagement device of the transmission is characterized by being lower than the hydraulic pressure based on the line pressure. The oil pressure based on the line pressure can be an oil pressure corresponding to the line pressure.

  In the control device for an automatic transmission according to the present invention, the hydraulic pressure to the friction engagement device is required to maintain the engagement state of the friction engagement device required to maintain the shift speed. The hydraulic pressure is set between the line pressure and the line pressure.

  In the control device for an automatic transmission according to the present invention, the hydraulic pressure to the friction engagement device is such that the difference in rotation speed of the friction engagement device required to maintain the shift speed is substantially a predetermined rotation speed difference. It is characterized by being controlled as follows.

  The control apparatus for an automatic transmission according to the present invention further comprises means for predicting whether or not a next shift is required within a predetermined period after the shift, and the necessity for the next shift within the predetermined period. If it is expected to occur, the frictional engagement required to maintain the shift stage after the shift is compared to a case where the need for the next shift is not expected to occur within the predetermined period. It is characterized in that the hydraulic pressure to the device is low.

  In the control device for an automatic transmission according to the present invention, there is provided a means for detecting that the traveling state of the vehicle is a state that easily affects the vehicle behavior, and the traveling state of the vehicle is a state that easily affects the vehicle behavior. Is detected in order to maintain the gear position after the shift, as compared with the case where it is not detected that the running state of the vehicle is likely to affect the vehicle behavior. The hydraulic pressure to the friction engagement device is low.

  In the control device for an automatic transmission according to the present invention, when it is detected that the traveling state of the vehicle is likely to affect the vehicle behavior, the traveling state of the vehicle is likely to affect the vehicle behavior. Compared to a case where it is not detected that the shift is not detected, the handling regarding the execution of the shift is changed.

  In the control apparatus for an automatic transmission according to the present invention, the state in which the traveling state of the vehicle is likely to affect the vehicle behavior includes a state in which the vehicle is entering a corner and a slip of a predetermined value or more on a tire of the vehicle. If a state in which the vehicle is entering a corner is detected, and a state in which the vehicle tire has slipping greater than or equal to a predetermined value is not detected, before the shift enters the end stage If so, the shift is stopped.

  In the control apparatus for an automatic transmission according to the present invention, the state in which the traveling state of the vehicle is likely to affect the vehicle behavior includes a state in which the vehicle is entering a corner and a slip of a predetermined value or more on a tire of the vehicle. If a state where the vehicle enters the corner and a state where the vehicle tires slip more than a predetermined value are detected, before and after the shift enters the end stage. Regardless of the case, the shift is stopped.

  In the control apparatus for an automatic transmission according to the present invention, the state in which the traveling state of the vehicle is likely to affect the vehicle behavior includes a state in which the vehicle is entering a corner and a slip of a predetermined value or more on a tire of the vehicle. If a state in which the vehicle is entering a corner is detected, and a state in which the vehicle tire has slipping greater than or equal to a predetermined value is not detected, before the shift enters the end stage The shift is stopped regardless of whether or not.

  According to the control device for an automatic transmission of the present invention, it is possible to suppress the deterioration of the shift characteristics and the shift delay.

  Hereinafter, an embodiment of a control device for an automatic transmission according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 5.

  In the first embodiment, after the shift is completed, the clutch torque is held at a low level that can secure the shift stage, or the friction engagement device is held at a predetermined relative rotational speed without ending the shift, Do the following: In other words, when the vehicle starts with the accelerator opening being the partial opening using the multi-stage automatic transmission, it is expected that the next shift determination will be made within a short period (time, distance) after the shift. In this case, the shift stage clutch torque is decreased from a lower level than usual, thereby suppressing the deterioration of the shift characteristics and the shift delay.

As a configuration of the present embodiment, (1) to (3) are assumed as will be described in detail below.
(1) Automatic transmission.
(2) A means for predicting whether or not the next shift is determined in a short time during a shift.
(3) Means for changing the current shift control mode based on the determination result of (2) above.

  In FIG. 2, reference numeral 10 is a stepped automatic transmission, and 40 is an engine. The automatic transmission 10 is capable of six-speed shifting by controlling the hydraulic pressure by energization / non-energization of the solenoid valves 121a, 121b, and 121c. In FIG. 2, three electromagnetic valves 121a, 121b, and 121c are illustrated, but the number of electromagnetic valves is not limited to three. The solenoid valves 121a, 121b, and 121c are driven by a signal from the control circuit 130.

  The throttle opening sensor 114 detects the opening of the throttle valve 43 disposed in the intake passage 41 of the engine 40. The engine speed sensor 116 detects the speed of the engine 40. The vehicle speed sensor 122 detects the rotation speed of the output shaft 120c of the automatic transmission 10 that is proportional to the vehicle speed. The shift position sensor 123 detects the shift position. The pattern select switch 117 is used when instructing a shift pattern.

  The acceleration sensor 90 detects vehicle deceleration (deceleration acceleration). The manual shift determination unit 94 outputs a signal indicating the necessity of downshift (manual downshift) or upshift by the driver's manual operation based on the driver's manual operation.

  The inter-vehicle distance measuring unit 100 has a sensor such as a laser radar sensor or a millimeter wave radar sensor mounted on the front of the vehicle, and measures the inter-vehicle distance from the front vehicle. The relative vehicle speed measuring unit 115 includes a sensor such as a millimeter wave radar sensor, and can directly measure the relative vehicle speed of the front vehicle and the host vehicle. Here, the relative vehicle speed is (own vehicle speed−front vehicle speed). The inter-vehicle distance measuring unit 100 and the relative vehicle speed measuring unit 115 are configured by a single (identical) millimeter wave radar.

  The road gradient measurement / estimation unit 118 can be provided as a part of the CPU 131. The road gradient measurement / estimation unit 118 can measure or estimate the road gradient based on the acceleration detected by the acceleration sensor 90. Further, the road gradient measuring / estimating unit 118 may store the acceleration on the flat road in the ROM 133 in advance and obtain the road gradient by comparing with the acceleration actually detected by the acceleration sensor 90.

  The navigation system device 95 has a basic function of guiding the host vehicle to a predetermined destination, and includes an arithmetic processing device and information (map, straight road, curve, uphill / downhill, highway) necessary for traveling the vehicle. Etc.), a first information detection device including a geomagnetic sensor, a gyrocompass, and a steering sensor, and a current position of the vehicle by radio navigation. It is for detecting a position, road conditions, etc., and is provided with a second information detection device including a GPS antenna and a GPS receiver.

  The control circuit 130 inputs signals indicating the detection results of the throttle opening sensor 114, the engine speed sensor 116, the vehicle speed sensor 122, the shift position sensor 123, the acceleration sensor 90, and the manual shift determination unit 94, and pattern selection. A signal indicating the switching state of the switch 117 is input, a signal indicating a detection or estimation result by the relative vehicle speed detection / estimation unit 115 is input, and a signal indicating a measurement result by the inter-vehicle distance measurement unit 100 is input. In addition, a signal from the navigation system device 95 is input.

  The control circuit 130 is configured by a known microcomputer and includes a CPU 131, a RAM 132, a ROM 133, an input port 134, an output port 135, and a common bus 136. The input port 134 includes signals from the sensors 114, 116, 122, 123, and 90, signals from the switch 117, a relative vehicle speed detection / estimation unit 115, a manual shift determination unit 94, a navigation system device 95, and Signals from each of the inter-vehicle distance measuring unit 100 are input. Solenoid valve driving units 138a, 138b, and 138c are connected to the output port 135.

  The ROM 133 stores in advance a program in which the operation (control step) shown in the flowchart of FIG. 1 is described, and a shift map (see FIG. 5) for shifting the shift stage of the automatic transmission 10 and shift control. An operation (not shown) is stored.

  The control circuit 130 determines the gear stage of the automatic transmission 10 based on the accelerator opening corresponding to the actual engine load and the vehicle speed from, for example, a pre-stored shift diagram shown in FIG. 5, and the determined gear stage. The automatic transmission control for controlling the solenoid valves 121a to 121c of the hydraulic control circuit provided in the automatic transmission 10 so as to establish the above is executed. The solid line in FIG. 5 is an upshift line, and the broken line is a downshift line.

  In the automatic transmission 10 having multiple stages (six stages in this example), the upshift lines and downshift lines in the shift diagram are densely arranged accordingly. In this case, as shown by an arrow P1 in FIG. 5, especially when the vehicle starts with the accelerator opening being a partial opening, the vehicle speed immediately exceeds the upshift line due to a relatively small increase in vehicle speed. The next shift (upshift) is performed in a short time after the first shift (upshift). Similarly, as shown by the arrow P2, even when the accelerator opening is close to being fully closed and the vehicle speed decreases (in the case of a course and downshifting), the vehicle speed immediately exceeds the downshift line due to a relatively small decrease in the vehicle speed. The next shift (downshift) is performed in a short time from the previous shift (downshift). In view of the above, an object of the present embodiment is to provide a control device for an automatic transmission capable of performing the next shift operation in a short time with little delay from the previous shift operation.

The operation of this embodiment will be described with reference to FIGS.
FIG. 4 shows a state when the vehicle starts with the accelerator opening being the partial opening.

  In FIG. 4, reference numeral 301 indicates the torque of the output shaft 120c of the automatic transmission 10 according to the present embodiment, and reference numeral 301 'indicates the torque of the output shaft 120c of the automatic transmission 10 according to the prior art. Reference numeral 302 indicates the rotational speed of the engine 40. Reference numeral 500 indicates a line pressure of the hydraulic pressure of the clutch of the automatic transmission 10.

  Reference numeral 501 indicates the hydraulic pressure of the engagement clutch of the latest shift (release clutch of the shift next to the latest shift) according to the present embodiment, and reference numeral 501 ′ indicates the engagement clutch ( The hydraulic pressure of the release side clutch of the next speed change after the latest speed change is shown. Reference numeral 502 indicates the hydraulic pressure of the engagement-side clutch of the next shift after the latest shift, and reference numeral 502 ′ indicates the hydraulic pressure of the engagement-side clutch of the next shift after the latest shift in the prior art.

[Step S10]
In step S <b> 10 of FIG. 1, the control circuit 130 determines whether or not there is a shift determination. Here, referring to the shift diagram of FIG. 5, based on the accelerator opening and the vehicle speed, whether or not there is a shift determination due to exceeding the shift line (including both the upshift line and the downshift line), and the manual It is determined whether or not there is a shift determination of manual shift determined by the shift determination unit 94. As a result of the determination in step S10, if it is determined that there is a shift determination, the process proceeds to step S20, and if not, the process proceeds to step S30.

  As a vehicle deceleration control based on the situation ahead of the vehicle, such as the size of the corner, road gradient, and inter-vehicle distance from the preceding vehicle, there is a shift point control technique for downshifting the shift stage of the automatic transmission. In S10, a shift determination by shift point control is also included.

  In step S10, if there is a shift determination of either upshift or downshift, a positive determination is made. In this example, the following operation will be described assuming that an upshift (power-on upshift) is determined in step S10. Note that the operation of FIG. 3 showing the details of step S40, which will be described later, corresponds to the case where any shift determination of upshift or downshift is made in step S10.

  In FIG. 4, since the shift determination is made at the time point of the symbol A, an affirmative determination is made in step S10, and the process proceeds to step S20.

[Step S20]
In step S20, a shift command (in this example, an upshift command) is output from the CPU 131 of the control circuit 130 to the solenoid valve driving units 138a to 138c. In response to the shift command, the solenoid valve driving units 138a to 138c energize or de-energize the solenoid valves 121a to 121c. As a result, the automatic transmission 10 executes a shift instructed by the shift command. In FIG. 4, the shift command is output at the same time (at time point A) when the control circuit 130 determines that there is a shift determination at time point A (step S10-Y).

  As shown in FIG. 4, when a gear shift command is output at the time of the symbol A (step S20), the gear shift of the automatic transmission 10 is started and the engagement side clutch hydraulic pressure (clutch torque) 501 starts to increase. Following step S20, step S30 is executed.

[Step S30]
In step S30, the control circuit 130 determines whether or not the latest shift has been completed. If it is determined that the latest shift has been completed, the process proceeds to step S40. If not, the control flow is reset.

  Even when a negative determination is made in step S10, the end of the latest shift is determined in step S30 even if there is no shift determination (step S10) in the current control flow. In this control flow, there is a shift determination, and the case where the shift based on the shift determination is in the shift operation is considered. In this example, as in step 10 above, the latest shift in step S30 is an upshift. In the example of FIG. 4, it is determined that the latest shift has been completed at the time point C.

[Step S40]
In step S40, the control circuit 130 determines whether or not it is highly likely that the next shift after the latest shift determined to have been completed in step S30 will be determined in a short time. As a result of the determination, if it is determined that the next shift is likely to be determined within a short time, the process proceeds to step S60, and if not, the process proceeds to step S50. The determination in step S40 is made based on the operation shown in FIG.

[Step SA31]
In step SA31 of FIG. 3, the control circuit 130 determines whether or not the accelerator is in an OFF state (fully closed) based on a signal from the throttle opening sensor 114. As a result of the determination in step SA31, if it is determined that the accelerator is OFF, the process proceeds to step SA37, and if not, the process proceeds to step SA32.

  When the accelerator opening is not fully closed (step SA31-N), it is assumed that the next shift is a power-on upshift (see arrow P1 in FIG. 5). On the other hand, when the accelerator opening is fully closed (step SA31-Y), it is assumed that the next shift is a coast downshift (see arrow P2 in FIG. 5). In this example, since it is determined that the accelerator opening is other than fully closed, the process proceeds to step SA32.

[Step SA32]
In step SA32, the control circuit 130 determines whether or not the current gear position of the automatic transmission 10 is the highest speed gear (sixth gear in this example). As a result of the determination, if it is determined that the current shift speed is the highest speed, the process proceeds to step SA39, and if not, the process proceeds to step SA33. If the current shift speed is the highest speed, the upshift is not determined as the next shift, and therefore the possibility that the next shift will be determined in a short time in step SA39 is small. Determined.

[Step SA33]
In step SA33, the control circuit 130 determines whether or not the vehicle speed is increasing based on the detection result from the vehicle speed sensor 122. As a result of the determination, if it is determined that the vehicle speed is increasing, the process proceeds to step SA34, and if not, the process proceeds to step SA39. This is because, as shown in the shift map in FIG. 5, if the vehicle speed is increasing, the next shift is determined sooner or later.

[Step SA34]
In step SA34, the control circuit 130 determines whether or not the accelerator opening is a partial opening based on a signal from the throttle opening sensor 114. As a result of the determination, if it is determined that the accelerator opening is the partial opening, the process proceeds to step SA35, and if not, the process proceeds to step SA39. When the accelerator opening is a partial opening, the shift line is more densely arranged on the shift map than when fully open, so the next shift is more likely to be judged in a short time. It is.

[Step SA35]
In step SA35, based on the signal from the throttle opening sensor 114, the control circuit 130 determines whether the change in the accelerator opening is smaller than a predetermined value or a change on the accelerator return side. The As a result of the determination, if the change in the accelerator opening is smaller than the predetermined value or a change on the accelerator return side, the process proceeds to step SA36. As shown by the arrow P1 in the shift map in FIG. 5, when the change in the accelerator opening is small or the change is on the side where the accelerator is returned, it is easy to cross the upshift line and the upshift (the next shift) is performed. It is because it is easy to be performed.

[Step SA36]
In step SA36, the control circuit 130 determines that there is a high possibility that the next shift will be determined in a short time. When all the conditions of step SA32 to step SA35 are cleared, it can be determined that the next shift (upshift) is likely to be determined in a short time. As will be described later, when both the conditions of step SA37 and step SA38 are cleared, it is possible to determine that the next shift (downshift) is likely to be determined in a short time. is there. As a result, the control circuit 130 returns to the control flow of FIG. 1 and makes a positive determination in step S40.

[Step SA37]
In step SA37, the control circuit 130 determines whether or not the current gear position of the automatic transmission 10 is the lowest gear speed (first speed in this example). As a result of the determination, if it is determined that the current shift speed is the lowest speed, the process proceeds to step SA39, and if not, the process proceeds to step SA38. If the current shift speed is the lowest speed, downshift is not determined as the next shift, and therefore the possibility that the next shift will be determined within a short time in step SA39 is small ( The possibility is not great).

[Step SA38]
In step SA38, the control circuit 130 determines whether or not the vehicle speed is decreasing based on the detection result from the vehicle speed sensor 122. As a result of the determination, if it is determined that the vehicle speed is decreasing, the process proceeds to step SA36, and if not, the process proceeds to step SA39. This is because, as shown in the shift map of FIG. 5, if the vehicle speed is decreasing, the next shift is determined sooner or later.

[Step SA39]
In step SA39, the control circuit 130 determines that the possibility that the next shift will be determined within a short time is small. If any of the conditions of Step SA32 to Step SA35, Step SA37, and Step SA38 is not satisfied, it can be determined that the possibility that the next shift is determined in a short time is small. As a result, the control circuit 130 returns to the control flow of FIG. 1 and makes a negative determination in step S40.

[Step S50]
In step S50 of FIG. 1, the CPU 131 of the control circuit 130 determines that the shift has been completed in step S30 (in this example, the shift is completed at point C in FIG. 4) (in this example, the latest shift) A command to increase the hydraulic pressure 501 of the engagement side clutch 501 to the line pressure 500 is output to the solenoid valve driving units 138a to 138c. A command to increase the hydraulic pressure 501 of the engagement clutch is output at point D in FIG.

  In this example, since the latest shift is an upshift, the engagement side clutch of the latest shift is a high side clutch. In response to the command to increase the hydraulic pressure 501 of the engagement side clutch, the solenoid valve drive units 138a to 138c energize or de-energize the solenoid valves 121a to 121c. As a result, the hydraulic pressure 501 of the engagement side clutch increases from the point D in FIG. 4 to the line pressure 500 (see reference numeral 501 ').

  In step S50, since it is determined in step S40 that the next shift (the shift next to the latest shift) is not determined in a short time (step S40-N), the conventional technique is determined. In the same manner as described above, the hydraulic pressure 501 of the engagement side clutch of the latest shift is increased to the line pressure 500. Following step S50, the control flow is returned.

[Step S60]
At step S60, the CPU 131 of the control circuit 130 determines the hydraulic pressure 501 of the engagement-side clutch of the latest shift determined that the shift has been completed at step S30, as the lower limit pressure at which the shift stage of the latest shift can be secured. A command to be held in 510 is output to the electromagnetic valve driving units 138a to 138c. A command to hold the hydraulic pressure 501 of the engaging clutch is output at point D in FIG.

  The lower limit pressure 510 that can ensure the latest gear position is determined based on, for example, the estimated input torque (engine torque) and the torque to be shared by the engagement side clutch. That is, the lower limit pressure 510 that can secure the latest gear stage is a hydraulic pressure corresponding to the minimum torque required to maintain the latest gear stage. After step S60, the control flow is returned.

  The effect of this embodiment will be described with reference to FIG.

  When the latest shift ends at point C in FIG. 4 (step S30-Y in FIG. 1), it is predicted that the next shift after the latest shift will be determined in a short time (step S40-Y). ), The hydraulic pressure 501 of the engagement side clutch is held as it is (it is held at the lower limit pressure 510 at which the latest gear stage can be secured, step S60).

  Thereafter (in the vicinity of point D), if a shift determination next to the latest shift is made, a shift command for the shift determination is output. In this case, the oil pressure 501 of the low gear clutch (the high-side clutch of the latest shift) subsequent to the latest shift is stably held at the lower limit pressure 510 that can secure the shift stage of the latest shift (step S60) From the point E (within a short time from the shift command for the next shift after the latest shift), the next shift after the latest shift can be started (see reference numeral 301). That is, the oil pressure 502 of the high side clutch (engagement side clutch) of the next shift of the latest shift can be quickly raised without delay.

  On the other hand, in the prior art, when the end of the latest shift is determined at point C in FIG. 4, the hydraulic pressure 501 of the engaging clutch is increased to the line pressure 500 (see reference numeral 501 '). In this case, even if the next shift determination is made immediately after the end of the latest shift, it takes time to reduce the hydraulic pressure 501 ′ of the engaging clutch that has been increased to the line pressure 500 for the shift. It was over.

  Specifically, first, it takes time to set the engagement-side clutch hydraulic pressure 501 'to the pressure adjustment mode again (symbol T1). Thereafter, as indicated by reference numeral (1), if the engagement side clutch hydraulic pressure 501 ′ is rapidly decreased, undershoot may occur and a downshift may occur for a moment. As described above, it is necessary to lower the temperature slowly to some extent, and time for that is required (reference T2). Thereafter, a waiting time (symbol T3) necessary for stably maintaining the hydraulic pressure after the decrease is required. As a result, the start of the next shift after the latest shift (timing to raise the hydraulic pressure 502 'of the high side clutch (engagement side clutch)) is delayed.

(First modification of the first embodiment)
Next, a first modification of the first embodiment will be described.
In this modification, the description of parts common to the first embodiment is omitted.

  In the first embodiment, the hydraulic pressure 501 of the engagement side clutch is described as being held at the lower limit pressure 510 (step S60) that can ensure the speed of the latest shift, but is not limited thereto. The clutch hydraulic pressure 501 can also be maintained at a value between the lower limit pressure 510 and the line pressure 500 that can ensure the speed of the latest shift. Also in this modified example, the hydraulic pressure 501 of the engagement side clutch can be quickly reduced as compared with the prior art in which the hydraulic pressure 501 ′ of the engagement side clutch is increased to the line pressure 500. The next shift of the latest shift can be started early.

(Second modification of the first embodiment)
Next, a second modification of the first embodiment will be described.
In this modification, the description of parts common to the first embodiment is omitted.

  The following method can be adopted as a method for determining whether or not the next shift is likely to be determined in a short time (step S40 in FIG. 1). The following method is a method when the next shift is an upshift. Based on the signal from the vehicle speed sensor 122, the rate of increase of the vehicle speed is obtained, and based on the rate of increase of the vehicle speed and the shift line (shift point) of the shift map, the time until the next shift is determined is estimated. If the estimated time is equal to or less than a predetermined value set in advance, it can be determined that the next shift is likely to be determined within a short time.

  The above method can also be applied when the next shift is a coast downshift. That is, a deceleration rate of the vehicle speed is obtained based on the signal from the vehicle speed sensor 122, and the time until the next shift is determined is determined based on the deceleration rate of the vehicle speed and the shift line (shift point) of the shift map. If the estimated time is less than or equal to a predetermined value set in advance, it can be determined that the next shift is likely to be determined within a short time.

(Third Modification of First Embodiment)
Next, a third modification of the first embodiment will be described.
In this modification, the description of parts common to the first embodiment is omitted.

  The following method can be adopted as a method for determining whether or not the next shift is likely to be determined in a short time (step S40 in FIG. 1). This method is used when the next shift is a coast downshift. Judgment based on whether or not the driver has operated the foot brake, and if there is an operation of the foot brake, it may be determined that there is a high possibility that a coast downshift accompanying a decrease in vehicle speed will be determined in a short time. it can.

(Fourth modification of the first embodiment)
In the first embodiment, in step S60, the hydraulic pressure 501 of the engagement side clutch of the latest shift, which has been determined to have been shifted in step S30, is set to the lower limit pressure that can ensure the gear position of the latest shift. The control to be held at 510 was performed. On the other hand, in this modification, it replaces with this control and the following structures are employ | adopted.

That is, the engagement side is set so that the rotational speed difference between the low speed clutch (or the high speed clutch) and the high speed clutch (or the low speed clutch) that is frictionally engaged is maintained at a predetermined rotational speed difference (for example, 50 rpm). A configuration in which the hydraulic pressure 501 of the clutch is feedback-controlled can be employed.
In this case, since there is a rotational speed difference (slip) between the low speed clutch (or the high speed clutch) and the high speed clutch (or the low speed clutch) that frictionally engages, it can be said that the shift is completely completed. Absent. In this modified example, the speed change is not completed, but at the time immediately before it (included in the speed change end stage), the high speed clutch (or the low speed clutch) that frictionally engages the low speed clutch (or the high speed clutch). Is controlled to feedback the clutch pressure so as to maintain a predetermined rotational speed difference.

(Fifth Modification of First Embodiment)
In the first embodiment, when it is determined in step S40 that there is a high possibility that the next shift will be determined in a short period of time, the hydraulic pressure 501 of the engagement side clutch is secured to the shift speed of the latest shift. Control was performed to keep the lower limit pressure 510 possible. Instead of this, it is possible to always perform control to maintain the engagement-side clutch hydraulic pressure 501 at the lower limit pressure 510 that can secure the latest shift speed without performing the determination in step S40. Further, it is possible to perform control to keep the friction engagement device at a predetermined relative rotational speed without always ending the shift without making the determination in step S40.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS.
In the second embodiment, description of parts common to the first embodiment is omitted.

  The present embodiment relates to a control device for an automatic transmission that performs deceleration control (corner control) by shifting the transmission based on information about a corner in front of the vehicle.

  In the second embodiment, after the shift is completed, the clutch torque is held at a low level that can secure the shift stage, or the friction engagement device is held at a predetermined relative rotational speed without ending the shift, Do the following: That is, in shift point control including corner control, when a downshift command is output, the low speed stage clutch pressure is maintained at the above level for a predetermined period of time, and at the time of turning determination or tire slip determination, the speed is quickly reduced. Release the clutch pressure for stage configuration and decrease the deceleration torque.

  If a vehicle turning determination or tire slip determination is made after a downshift command for corner control is output, the shift may be canceled if the determination is made before the start of the inertia phase of the shift. It has been. When vehicle turning judgment or tire slip judgment is made, it is desirable to cancel the downshift from the viewpoint of vehicle stability.However, canceling the shift after the start of the inertia phase causes a sense of incongruity and impairs drivability. The downshift is canceled only before the start of the inertia phase, and the downshift is executed as it is after the start of the inertia phase.

  On the other hand, in the present embodiment, the following steps [1] and [2] are taken according to the state after the downshift command is output.

[1] When there is a vehicle turning determination and there is no tire slip determination, even when the vehicle turning determination is made after the start of the inertia phase, a time point at which the gear shift ends (or a certain time point before the gear shift ends) If it is made before, the shift is cancelled.

  In the case of [1], unlike the case of [2] described later, the vehicle is in an unstable state only when there is vehicle turning determination (the vehicle is cornering) (tire slip determination is Therefore, simply canceling the gear shift maintains the gear before the gear shift, and does not upshift from the gear before the gear shift.

[2] When there is a vehicle turning determination and a tire slip determination, even if the determination is made after the time when the gear shift ends (or some time before the gear shift ends), the gear shift And the upshift is performed from the gear position before the gear shift, and the deceleration force is reduced (in the following example, this shift is performed only when the destination gear gear position of the gear shift is equal to or less than a predetermined gear position. The operation of [2] is performed).

  Canceling the shift or reducing the clutch engagement pressure during a shift may cause the driver to feel uncomfortable, as well as causing the driver to feel uncomfortable because the engine speed also changes from increasing to decreasing. . However, if there is a tire slip determination, the vehicle may become unstable. Therefore, priority is given to the feeling to cancel the shift and to decrease the clutch engagement pressure.

  In the present embodiment, as a shift point control based on the distance between the front corner, the road gradient, or the preceding vehicle, or based on a downshift command from the driver, at least the gear position and the gear ratio of the transmission are changed to change the speed. When the vehicle turning determination or tire slip determination is performed, the above [1] or [2] is performed even after the start of gear shifting (after the start of the inertia phase) to prevent an increase in deceleration. To control the transmission.

  As described in detail below, the configuration of the present embodiment is at least when the driver's intention to decelerate is detected based on the automatic transmission capable of changing the gear position or the gear ratio and the preceding corner R. It is premised on a means for controlling the deceleration of the vehicle by a shift and a means for changing and controlling the mode of the shift control based on at least the type of the shift and the traveling environment.

  FIG. 7 is a diagram showing a schematic configuration of the second embodiment. In FIG. 7, the same components as those in FIG. 2 are given the same reference numerals, and detailed descriptions thereof are omitted.

  The tire slip determination unit 91 detects the presence or absence of tire slip. The tire slip determination unit 91 performs various conditions, for example, a rotational speed (driven wheel speed) of a front wheel (not shown) detected by a front wheel speed sensor (not shown) and a rear wheel (detected by a vehicle speed sensor 122). The presence / absence of tire slip is detected based on the difference in rotational speed (drive wheel speed).

  Here, the specific method of detecting the presence or absence of tire slip by the tire slip determination unit 91 is not particularly limited, and a known method can be appropriately employed. For example, in addition to the wheel speed difference before and after the above, the rate of change of wheel speed, ABS (anti-lock brake system), TRS (traction control system) and VSC (vehicle stability control) operation The presence or absence of tire slip can be detected using at least one of the relationship between the history, the acceleration of the vehicle, and the wheel slip ratio.

  The road surface μ detection / estimation unit 92 detects or estimates the slipperiness of the road surface represented by the road surface friction coefficient μ (whether the road surface is a low μ road). Here, the low μ road includes a bad road (including a case where the road surface has large unevenness or a step on the road surface). That is, the road surface μ detection / estimation unit 92 calculates the friction coefficient μ of the traveling road surface, and determines whether the road is a low μ road depending on whether the calculated friction coefficient μ exceeds a predetermined threshold value. Is determined.

  The road surface μ detection / estimation unit 92 predicts whether the road surface is a low μ road, based on information (navigation information, etc.) about the road surface scheduled to travel in the future. Here, the navigation information includes information on road surfaces (for example, non-paved roads) recorded in advance on a storage medium (DVD, HDD, etc.) as in the navigation system device 95, as well as past actual driving and other information. Information (including information indicating road conditions and information indicating weather conditions) obtained through communication (including vehicle-to-vehicle communication and road-to-vehicle communication) with other vehicles and communication centers. Such communications include road traffic information communication systems (VICS) and so-called telematics.

  The control circuit 130 inputs signals indicating the detection results of the tire slip determination unit 91 and the road surface μ detection / estimation unit 92.

  Signals from the tire slip determination unit 91 and the road surface μ detection / estimation unit 92 are input to the input port 134 of the control circuit 130. The output port 135 is connected to the electromagnetic valve driving units 138a, 138b, 138c and the brake braking force signal line L1 to the brake control circuit 230. A brake braking force signal SG1 is transmitted through the brake braking force signal line L1.

  The brake device 200 is controlled by a brake control circuit 230 that receives a brake braking force signal SG1 from the control circuit 130, and brakes the vehicle. The brake device 200 includes a hydraulic control circuit 220 and braking devices 208, 209, 210, and 211 provided on the wheels 204, 205, 206, and 207 of the vehicle, respectively. Each of the braking devices 208, 209, 210, and 211 controls the braking force of the corresponding wheels 204, 205, 206, and 207 when the hydraulic pressure is controlled by the hydraulic control circuit 220. The hydraulic control circuit 220 is controlled by the brake control circuit 230.

  The hydraulic control circuit 220 performs brake control by controlling the braking hydraulic pressure supplied to each braking device 208, 209, 210, 211 based on the brake control signal SG2. The brake control signal SG2 is generated by the brake control circuit 230 based on the brake braking force signal SG1. The brake braking force signal SG1 is output from the control circuit 130 of the automatic transmission 10 and input to the brake control circuit 230. The brake force applied to the vehicle during the brake control is determined by a brake control signal SG2 generated by the brake control circuit 230 based on various data included in the brake braking force signal SG1.

  The brake control circuit 230 is configured by a known microcomputer and includes a CPU 231, a RAM 232, a ROM 233, an input port 234, an output port 235, and a common bus 236. A hydraulic control circuit 220 is connected to the output port 235. The ROM 233 stores an operation for generating the brake control signal SG2 based on various data included in the brake braking force signal SG1. The brake control circuit 230 controls the brake device 200 (brake control) based on each input control condition.

  The operation of this embodiment will be described with reference to FIGS.

  FIG. 8 is a chart for explaining the deceleration control of the present embodiment. FIG. 8 shows the control execution boundary L, the required deceleration 401, the target turning vehicle speed Vreq, the road shape top view, and the point a where the accelerator is OFF (the accelerator opening is fully closed).

  In FIG. 9, reference numeral 601 indicates the torque of the output shaft 120c of the automatic transmission 10 of the present embodiment, and reference numeral 601 'indicates the torque of the output shaft 120c of the automatic transmission 10 in the prior art. Reference numeral 700 indicates a line pressure of the hydraulic pressure of the clutch of the automatic transmission 10.

  Reference numeral 701 indicates the hydraulic pressure of the downshift engagement side clutch by corner control of the present embodiment, and reference numeral 701 ′ indicates the hydraulic pressure of the downshift engagement side clutch by corner control in the prior art.

[Step SB10]
In step SB10 of FIG. 6, the control circuit 130 determines whether or not the accelerator is in an OFF state (fully closed) based on a signal from the throttle opening sensor 114. If it is determined in step SB10 that the accelerator is in an OFF state, the process proceeds to step SB20. When the accelerator is fully closed (step SB10-Y), it is determined that the driver intends to decelerate, and the deceleration control of this embodiment is performed. On the other hand, if it is not determined that the accelerator is in the OFF state, the process proceeds to step SB125. As described above, in FIG. 8, the accelerator opening is zero (fully closed) at the position (time point) a.

[Step SB20]
In step SB20, the control circuit 130 checks the flag F. As a result, if the flag F is 0, the process proceeds to step SB30. If the flag F is 1, the process proceeds to step SB60. If the flag F is 2, the process proceeds to step SB80. When this control flow is executed, since the flag F is initially 0, the process proceeds to step SB30.

[Step SB30]
In step SB30, the control circuit 130 determines whether or not the present control is necessary based on, for example, the control execution boundary line L. In the determination, in FIG. 8, it is determined that the present control is necessary if it is located above the control execution boundary line L due to the relationship between the current vehicle speed and the distance to the entrance 403 of the corner 402, and the control execution boundary line is determined. If it is positioned lower than L, it is determined that this control is unnecessary. As a result of the determination in step SB30, if it is determined that this control is necessary, the process proceeds to step SB40. If it is determined that this control is not necessary, this control flow is returned.

  The control execution boundary line L is a relationship between the current vehicle speed and the distance to the point c just before the entrance 403 of the corner 402, unless a deceleration exceeding a preset deceleration by normal braking acts on the vehicle. This is a line corresponding to a range in which the target turning vehicle speed Vreq cannot be reached at the point c before the entrance 403 of the corner 402 (the corner 402 cannot be turned at a desired turning G). That is, when the vehicle is positioned above the control execution boundary L, in order to reach the target turning vehicle speed Vreq at the point c before the entrance 403 of the corner 402, the deceleration by the normal braking set in advance is exceeded. It is necessary for the deceleration to act on the vehicle.

  Therefore, when the position is higher than the control execution boundary line L, deceleration control corresponding to the corner R of the present embodiment is executed (step SB50), and the amount of brake operation by the driver is increased by increasing the deceleration. Even if there is no gear or the operation amount is relatively small (even if the foot brake is stepped on only a little), the target turning vehicle speed Vreq can be reached at a point c before the entrance 403 of the corner 402.

  As the control execution boundary line L of the present embodiment, a control execution boundary line used for shift point control corresponding to a conventional general corner R can be applied as it is. The control execution boundary line L is created by the control circuit 130 based on the data input from the navigation system device 95 and indicating the distance between R405 of the corner 402 and the corner.

  In the present embodiment, in FIG. 8, the time point corresponding to the symbol a at which the accelerator opening is zero is located above the control execution boundary line L, so that it is determined that this control is necessary (step SB30-Y). ), Go to Step SB40.

[Step SB40]
In step SB40, the control circuit 130 determines a gear position to be selected when the automatic transmission 10 is controlled to shift (shift down). In determining the speed to be selected, first, the required deceleration is obtained, and then the speed to be selected is determined based on the required deceleration. Hereinafter, the calculation of the required deceleration will be described as (A), and then the determination of the shift speed to be selected will be described as (B).

(A) Calculation of Required Deceleration The required deceleration is calculated by the control circuit 130. The necessary deceleration is a deceleration required to turn the other corner at a predetermined desired turning G (in order to enter the corner at a desired vehicle speed Vreq). In FIG. 8, the required deceleration is indicated by reference numeral 401.

  In FIG. 8, the horizontal axis indicates the distance, and as shown in the “top view of the road shape”, the front corner 402 exists from the point 403 to the point 404. A target turn corresponding to the radius (or curvature) R405 of the corner 402 at a point c that is offset by a predetermined amount from the entrance 403 of the corner 402 to turn the corner 402 at a predetermined desired turn G. It has to be decelerated to the vehicle speed Vreq. That is, the target turning vehicle speed Vreq is a value corresponding to R405 of the corner 402.

  In order to decelerate from the vehicle speed at the location a where the accelerator is determined to be fully closed in step SB10 to the target turning vehicle speed Vreq required at the point c just before the entrance 403 of the corner 402, the required deceleration 401 is indicated. Such deceleration is required. The control circuit 130 is based on the current vehicle speed input from the vehicle speed sensor 122, the distance from the current position to the entrance 403 of the corner 402 (point c before) and the R405 of the corner 402, which are input from the navigation system device 95. The necessary deceleration 401 is calculated.

(B) Determination of the shift speed to be selected In the ROM 133, vehicle characteristic data indicating the deceleration G for each vehicle speed at each shift speed when the accelerator is OFF as shown in FIG.

  Here, assuming that the output rotational speed is 1000 [rpm] and the required deceleration 401 is −0.18 G, in FIG. 10, it corresponds to the vehicle speed when the output rotational speed is 1000 [rpm]. Further, it can be seen that the speed stage where the deceleration closest to −0.18G of the necessary deceleration 401 is the third speed. Thereby, in the case of the above example, in step SB40, it is determined that the gear to be selected is the third speed.

  In this example, the speed stage closest to the necessary deceleration 401 is selected as the speed stage to be selected. However, the speed stage to be selected is a deceleration of the required deceleration 401 or lower (or higher). Thus, the gear position that provides the closest deceleration to the required deceleration 401 may be selected. Step SB50 is executed after step SB40.

[Step SB50]
In step SB50, the control circuit 130 outputs a shift command related to the gear stage to be selected, which is determined in step SB40. That is, a downshift command (shift command) is output from the CPU 131 of the control circuit 130 to the solenoid valve driving units 138a to 138c.

  In this case, if the shift stage to be selected (destination shift stage) determined in step SB40 is higher than the predetermined stage set in advance (high gear stage), after the shift is completed, the engagement side clutch A command to increase the hydraulic pressure 701 to the line pressure 700 is included in the downshift command (see reference numeral 701 ′).

  On the other hand, if the gear to be selected (destination gear) determined in step SB40 is a gear that is equal to or lower than a predetermined gear set in advance, the hydraulic pressure 701 of the engaging clutch is The downshift command includes a command for holding the lower limit pressure 710 that can secure the gear to be selected.

  The preset predetermined stage is, for example, the third speed, and in the above example, the speed stage to be selected is the third speed. A command for holding the hydraulic pressure 701 at the lower limit pressure 710 that can ensure the above-described shift speed to be selected is included.

  In response to the downshift command, the solenoid valve driving units 138a to 138c energize or de-energize the solenoid valves 121a to 121c. As a result, the automatic transmission 10 performs a shift instructed by the downshift command.

  When the downshift command is determined by the control circuit 130 at the location (time point) corresponding to the symbol a in FIG. It is output at the time corresponding to the symbol a in FIG. 8 and the point in time A in FIG. As a result, the automatic transmission 10 starts a downshift operation toward the gear position to be selected (third speed in the above example) determined as described above from the time corresponding to the symbol A in FIG. As the engagement side hydraulic pressure 701 rises, the engine braking force (output shaft torque 601) increases, and the deceleration due to the gear position of the automatic transmission 10 increases from the location (time point) of the symbol a. Step SB60 is executed after step SB50.

[Step SB60]
In step SB60, the control circuit 130 determines whether or not the vehicle has entered the corner 402 (vehicle turning determination). The control circuit 130 makes the determination in step SB60 based on the size of the lateral G of the vehicle. Alternatively, the determination in step SB60 is performed based on the data input from the navigation system device 95 and indicating the current position of the vehicle and the position of the entrance 403 of the corner 402. As a result of the determination in step SB60, if it is after entering the corner 402, the process proceeds to step SB70, and if not, the process proceeds to step SB160.

  In the first stage in which this control flow is implemented, the vehicle has not entered the corner 402 (step SB60-N), and therefore whether or not there is tire slip is determined in step SB160.

[Step SB160]
In step SB160, the control circuit 130 determines the presence or absence of tire slip based on the signal input from the tire slip determination unit 91. As a result of the determination, if it is determined that there is a tire slip exceeding a predetermined value, the process proceeds to step SB170, and if not, the process proceeds to step SB180.

  In step SB160, it is determined whether or not the road surface is a low μ road based on not only the presence / absence of tire slip but also a signal input from the road surface μ detection / estimation unit 92. If it is determined that there is a low μ road, the process proceeds to step SB170, and if it is determined not to be any case, the process may proceed to step SB180 (step SB80 and step below). The same applies to SB105).

[Step SB170]
In step SB170, the control circuit 130 restricts new upshifts and downshifts. Upshifting to a relatively high speed gear stage is restricted from the gear position (third speed in the above example) related to the downshift command output in step SB50. Also, regarding downshifting, downshifting to a relatively low speed gear stage is restricted relative to the gear stage related to the downshift command output in step SB50. This is to prevent an increase in deceleration and contribute to vehicle stability.

  Further, in step SB170, if the shift related to the downshift command output in step SB50 is earlier than the time point (or a certain time point before the shift end), the engagement side The clutch hydraulic pressure 701 is reduced. After step SB170, the process proceeds to step SB180.

[Step SB180]
In step SB180, the flag F is set to 1 and this control flow is reset. In the control flow again, when the accelerator is fully closed (step SB10-Y), since the flag F is 1 (step SB20-1), the process proceeds to step SB60 and is repeated until the condition of step SB60 is satisfied. It is.

[Step SB70]
In step SB70, the control circuit 130 restricts new upshifts and downshifts. During cornering after entering the corner 402, it is restricted that the gear is shifted up to a higher gear than the gear associated with the downshift command output in step SB50 (third speed in the above example). Is done. Normally, even in a shift point control for a general corner, an upshift during cornering after entering the corner is prohibited. Further, regarding downshifting, during cornering after entering the corner 402, it is restricted that the downshifting is performed at a lower speed than the speed associated with the downshift command output in step SB50. Is done. This is to prevent an increase in deceleration and contribute to vehicle stability.

  Further, in step SB70, if the shift related to the downshift command output in step SB50 is before the end of the shift (or a certain time before the end of the shift), the engagement side cancels the shift. The clutch hydraulic pressure 701 is reduced. After step SB70, the process proceeds to step SB80.

[Step SB80]
In step SB80, as in step SB160, the control circuit 130 determines the presence or absence of tire slip based on the signal input from the tire slip determination unit 91. As a result of the determination, if it is determined that there is a tire slip exceeding a predetermined value, the process proceeds to step SB90, and if not, the process proceeds to step SB100.

[Step SB90]
In step SB90, if the shift stage to be selected (destination shift stage) determined in step SB40 by the control circuit 130 is a predetermined shift stage or less, the downshift command In order to cancel the shift and prepare for the upshift from the shift stage before the next shift regardless of before or after the end of the shift (or a certain point before the end of the shift), The hydraulic pressure 701 is reduced. In the upshift, the clutch hydraulic pressure 701 becomes the low-gear clutch hydraulic pressure 701.

  When the gear to be selected is a gear that is equal to or less than a predetermined gear set in advance, the lower limit at which the hydraulic pressure 701 of the engagement side clutch can secure the gear to be selected after the shift is completed. Since the pressure is held at the pressure 710 and does not increase to the line pressure 700 (step SB50), the deceleration can be reduced substantially simultaneously with the output of the lowering command of the hydraulic pressure 701 of the engagement side clutch in step SB90.

  In step SB90, the hydraulic pressure 701 of the engagement side clutch that forms the shift stage that is the shift stage to be selected is equal to or lower than the lower limit pressure 710 that can secure the shift stage to be selected. If not, step SB90 is not executed and remains as it is. That is, the upshift by step SB90 is not performed. Here, when the hydraulic pressure 701 of the engagement side clutch has not increased to the lower limit pressure 710 that can ensure the shift speed to be selected, the shift to the shift speed to be selected ends in step SB70. This is a case where the hydraulic pressure 701 of the engagement side clutch is lowered before the time point.

  For this reason, in step SB90, when the hydraulic pressure 701 of the engagement side clutch that forms the gear stage equal to or lower than the predetermined speed is lowered, the hydraulic pressure 701 of the engagement side clutch already secures the gear stage to be selected. This is a case where the tire slip determination (step SB80) is performed after the possible lower limit pressure 710 is reached and a gear position equal to or lower than the predetermined gear speed is selected. Following step SB90, step SB100 is performed.

[Step SB100]
In step SB100, control circuit 130 determines whether or not the vehicle has exited corner 402. The control circuit 130 determines whether or not the vehicle has escaped the corner 402 based on the lateral G acting on the vehicle. Alternatively, based on the data input from the navigation system device 95 and indicating the current position of the vehicle and the position of the exit 404 of the corner 402, the determination in step SB100 is performed. If the result of determination in step SB100 is that the corner 402 has been escaped, the process proceeds to step SB105, and if not, the process proceeds to step SB190.

  Since the vehicle has not escaped from the corner 402 at the first stage when this control flow is executed (step SB100-N), the flag F is set to 2 in step SB190, and this control flow is reset. In the control flow again, when the accelerator is fully closed (step SB10-Y), since the flag F is 2 (step SB20-2), tire slip determination is made (step SB80). When the determined gear to be selected is a gear that is equal to or lower than a predetermined gear set in advance, the hydraulic pressure of the engagement side clutch can be used regardless of before or after the end of the gear shift according to the downshift command. After decreasing 701 (step SB90), the process proceeds to step SB100 and is repeated until the condition of step SB100 is satisfied. If the condition of step SB100 is satisfied (step SB100-Y), the process proceeds to step SB105.

[Step SB105]
In step SB105, the presence or absence of tire slip is determined by the control circuit 130 based on the signal input from the tire slip determination unit 91, as in step SB160. As a result of the determination, if it is determined that there is a tire slip exceeding a predetermined value, the process proceeds to step SB120, and if not, the process proceeds to step SB110.

[Step SB110]
In step SB110, the control circuit 130 outputs a command for increasing the hydraulic pressure 701 of the engaging clutch to the line pressure 700 when the gear to be selected is a gear that is equal to or lower than a predetermined gear set in advance. Is done. Following step SB110, step SB120 is performed.

[Step SB120]
In step SB120, the shift restriction is canceled by the control circuit 130. As a result, the upshift and downshift restrictions performed in step SB70 are released. In step SB120, the control circuit 130 sets the flag F to 0. After step SB120, this control flow is reset.

[Step SB125] to [Step SB150]
When the accelerator is not fully closed (step SB10-N), as in step SB110, if the gear to be selected is a gear that is equal to or lower than a predetermined gear set in advance, the engagement side A command to increase the hydraulic pressure 701 of the clutch to the line pressure 700 is output (step SB125). Thereby, the gear stage to be selected is determined. Thereafter, it is determined whether cornering is in progress (step SB130). If the result of the determination is cornering (step SB130-Y), this control flow is reset. When cornering is not being performed (step SB130-N), the shift restriction is released (step SB140), and the flag F is cleared and reset (step SB150). Note that in the initial state when this control is started, the shift is not restricted and the flag F is also 0, so it remains as it is.

  According to this embodiment described above, the following effects can be obtained.

  FIG. 9 shows the output shaft torque 601 and the engagement side clutch hydraulic pressure 701 when a downshift is performed by corner control. When the downshift command by corner control is output (step SB50), the hydraulic pressure 701 of the engagement side clutch increases, and the deceleration due to the output shaft torque 601 increases. Shifting ends at point C in FIG. In this case, when the destination shift stage of the downshift is equal to or less than the predetermined stage, the hydraulic pressure 701 of the engagement side clutch is held at the lower limit pressure 710 that can secure the destination shift stage after the shift is completed, and the line pressure Control is performed so as not to increase to 700 (step SB50).

  When the tire slip is detected at point E in FIG. 9 after the end of the shift (step SB80-Y), the engagement side is canceled to cancel the shift and prepare for the upshift from the next shift stage before the shift. The clutch hydraulic pressure 701 is reduced. In this case, since the hydraulic pressure 701 of the engagement side clutch is held at the lower limit pressure 710 that can secure the destination shift speed and does not increase to the line pressure 700 (step SB50), the tire slip is determined after the shift is completed. In this case, the deceleration can be reduced substantially at the same time as the tire slip determination. On the other hand, in the prior art, the hydraulic pressure 701 ′ of the engagement side clutch is increased to the line pressure 700 after the end of the shift, so it takes time to reduce the hydraulic pressure 701 ′ of the engagement side clutch. Decreasing speed will be delayed.

  Further, according to the present embodiment, when cornering is being performed (step SB60-Y), or when non-cornering is being performed (running on a straight road), and there is tire slip (step SB60-N, step SB160). -Y), until the corner is escaped (step SB100-Y), new upshifts and downshifts are restricted (step SB70 or step SB170), and the shift command is canceled for incomplete shifts. Accordingly, the hydraulic pressure 701 of the engagement side clutch is reduced (step SB70 or step SB170). When cornering is in progress, an increase in vehicle deceleration may impair vehicle stability, so an incomplete downshift command is canceled. Also, when there is a tire slip on a straight road, an uncompleted downshift command is canceled for the same reason.

  Further, when the vehicle is cornering (step SB60-Y) and there is tire slip (step SB80-Y), the gear to be selected is a gear that is equal to or less than a predetermined gear set in advance. In some cases, regardless of whether the shift is completed or not, the shift command is canceled and the hydraulic pressure 701 of the engaging clutch is decreased so that the upshift is performed (step SB90). If there is a tire slip determination during cornering, the vehicle is in an unstable state, but if the gear to be selected is a gear below a predetermined gear set in advance, a large deceleration Because this acts on the vehicle, canceling the shift and performing an upshift reduces the deceleration and contributes to vehicle stability.

(First Modification of Second Embodiment)
In the second embodiment, the corner control is described as being performed by controlling the gear position of the stepped automatic transmission 10, but instead, the control of the gear ratio of the CVT can be performed. In the case of CVT, the shift is stopped when the turning determination that cornering is being performed or when it is determined that the tire is slipping.

(Second Modification of Second Embodiment)
In the first embodiment, the corner control is performed only by the shift control of the automatic transmission, but can be performed by the cooperative control of the automatic transmission and the brake. In this case, not only the shift control of the automatic transmission 10 but also the feedback control of the brake device 200 is executed by the brake control circuit 230. The brake feedback control means that the braking force is controlled according to the deviation between the target deceleration (required deceleration 401) and the actual deceleration of the vehicle.

  The brake feedback control is started at the location a where the downshift command is output. That is, a signal indicating the required deceleration 401 is output from the control circuit 130 to the brake control circuit 230 via the brake braking force signal line L1 as the brake braking force signal SG1. The brake control circuit 230 generates a brake control signal SG2 based on the brake braking force signal SG1 input from the control circuit 130, and outputs the brake control signal SG2 to the hydraulic control circuit 220.

  The hydraulic control circuit 220 controls the hydraulic pressure supplied to the braking devices 208, 209, 210, and 211 based on the brake control signal SG2, so that the braking force (brake control amount) as instructed in the brake control signal SG2 is achieved. Is generated.

  In the feedback control of the brake device 200, the target value is the necessary deceleration 401, the control amount is the actual deceleration of the vehicle, the control target is the brake (braking devices 208, 209, 210, 211), and the operation amount is This is a brake control amount, and the disturbance is mainly a deceleration due to a shift of the automatic transmission 10. The actual deceleration of the vehicle is detected by the acceleration sensor 90 or the like.

  That is, in the brake device 200, the brake braking force (brake control amount) is controlled so that the actual deceleration of the vehicle becomes the required deceleration 401. That is, the brake control amount is set so as to cause a deceleration that is insufficient for the deceleration due to the shift of the automatic transmission 10 when the required deceleration 401 is generated in the vehicle.

  Note that the brake control in the second modified example may be performed by using a braking device that generates a braking force on the vehicle, such as a regenerative braking by an MG device provided in the power train system, instead of the brake. .

(Third Modification of Second Embodiment)
Although the said 2nd Embodiment showed the example applied to the corner control, in a 3rd modification, it is not limited to corner control, It can apply also to uphill / downhill control and follow-up control. In this case, the configuration of the inter-vehicle distance measurement unit 100, the relative vehicle speed measurement unit 115, and the road gradient measurement / estimation unit 118 of FIG. 2 can be used.

(Fourth modification of the second embodiment)
In the fourth modified example, the road surface μ detection / estimation unit 92 outputs the shift regulation command (step SB70, step SB170) and the engagement pressure gradual decrease command (step SB90) on the low μ road. It is limited when it is determined. As described above, if the gear shift command is canceled during the inertia phase or after the gear shift is finished, the feeling of deceleration is lost, and the engine speed also changes from increasing to decreasing, which may cause discomfort. For this reason, the shift command is canceled during the inertia phase or after the end of the shift only when the vehicle stability is to be emphasized.

(Fifth Modification of Second Embodiment)
In the second embodiment, in step SB50, if the gear to be selected (destination gear) determined in step SB40 is a gear that is equal to or less than a predetermined gear set in advance, Control was performed to maintain the hydraulic pressure 701 of the engagement side clutch at the lower limit pressure 710 that can ensure the above-described shift speed to be selected. On the other hand, in this modification, it replaces with this control and the following structures are employ | adopted.

That is, the engagement side is set so that the rotational speed difference between the low speed clutch (or the high speed clutch) and the high speed clutch (or the low speed clutch) that is frictionally engaged is maintained at a predetermined rotational speed difference (for example, 50 rpm). A configuration in which the hydraulic pressure 701 of the clutch is feedback-controlled can be employed.
In this case, since there is a rotational speed difference (slip) between the low speed clutch (or the high speed clutch) and the high speed clutch (or the low speed clutch) that frictionally engages, it can be said that the shift is completely completed. Absent. In this modified example, the speed change is not completed, but at the time immediately before it (included in the speed change end stage), the high speed clutch (or the low speed clutch) that frictionally engages the low speed clutch (or the high speed clutch). Is controlled to feedback the clutch pressure so as to maintain a predetermined rotational speed difference.

(Sixth Modification of Second Embodiment)
In the second embodiment, in step SB50, when the shift stage to be selected (destination shift stage) determined in step SB40 is a shift stage that is equal to or lower than a predetermined stage that is set in advance, Then, control was performed to maintain the hydraulic pressure 701 of the engagement side clutch at the lower limit pressure 710 that can ensure the above-described shift speed to be selected. Instead of this, regardless of the shift stage to be selected (destination shift stage), the hydraulic pressure 701 of the engagement side clutch is always set to the lower limit pressure 710 that can secure the shift stage to be selected after the end of the shift. Can be controlled. Regardless of the shift speed to be selected (destination shift speed), it is possible to perform control to keep the friction engagement device at a predetermined relative rotational speed without always ending the shift.

(Seventh Modification of Second Embodiment)
In the second embodiment, as described in [2] above, when there is a vehicle turning determination and there is also a tire slip determination, these determinations are made after the point in time when the shift ends. Even if there is, control for canceling the shift and upshifting from the shift stage before the shift was performed. In this modification, instead of this, even when there is a vehicle turning determination and there is no tire slip determination, the shift is canceled even if the determination is made after the end of the shift. In addition, it is possible to perform control for upshifting from the gear position before the gear change.

  In the above description, the deceleration indicating the amount that the vehicle should decelerate has been described using the deceleration acceleration (G), but it is also possible to control based on the deceleration torque.

  From the above embodiments, the following items are disclosed.

(Claim 1)
If it is expected that the next shift determination will be made in a short time after the shift of the multi-stage automatic transmission is completed, the clutch torque is maintained at a level that can secure the shift stage, or the shift is not ended. A control device for an automatic transmission, characterized in that a deterioration in shift characteristics and a shift delay are suppressed by maintaining the friction engagement device at a predetermined relative rotational speed.

(Section 2)
When a downshift command (including corner control, uphill / downhill control, follow-up control, manual shift, or shift based on a shift map) is output, the low-speed-stage clutch pressure is maintained at a predetermined level that can maintain the shift speed even after shifting. An automatic transmission characterized by holding or holding a predetermined low relative rotational speed, quickly releasing the clutch pressure for low-speed gear configuration at the time of turning judgment or tire slip judgment, and quickly reducing the deceleration torque Machine control device.

(Section 3)
A control device for an automatic transmission, wherein a control (treatment) method is changed when at least one of turning determination and tire slip determination occurs after a shift command by corner control is output. For example, when the vehicle is cornering and there is no tire slip determination, the shift is canceled before the start of the shift or before the end of the shift. During cornering and when there is a tire slip determination, the shift is canceled even after the shift is completed.

It is a flowchart which shows operation | movement of 1st Embodiment of the control apparatus of the automatic transmission of this invention. It is a schematic block diagram of 1st Embodiment of the control apparatus of the automatic transmission of this invention. It is a flowchart which shows other operation | movement of 1st Embodiment of the control apparatus of the automatic transmission of this invention. It is a figure for demonstrating the effect of 1st Embodiment of the control apparatus of the automatic transmission of this invention. It is a figure which shows the shift map in 1st Embodiment of the control apparatus of the automatic transmission of this invention. It is a flowchart which shows operation | movement of 2nd Embodiment of the control apparatus of the automatic transmission of this invention. It is a schematic block diagram of 2nd Embodiment of the control apparatus of the automatic transmission of this invention. It is a figure for demonstrating operation | movement of 2nd Embodiment of the control apparatus of the automatic transmission of this invention. It is a figure for demonstrating the effect of 2nd Embodiment of the control apparatus of the automatic transmission of this invention. In the second embodiment of the automatic transmission control device of the present invention, it is a diagram showing the deceleration for each vehicle speed of each shift stage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automatic transmission 40 Engine 90 Acceleration sensor 91 Tire slip determination part 92 Road surface micro | micron | mu. Detection / estimation part 94 Manual shift determination part 95 Navigation system apparatus 100 Inter-vehicle distance measurement part 114 Throttle opening sensor 115 Relative vehicle speed measurement part 116 Engine rotation speed sensor 118 Road Gradient Measurement / Estimation Unit 122 Vehicle Speed Sensor 123 Shift Position Sensor 130 Control Circuit 131 CPU
133 ROM
200 Brake Device 230 Brake Control Circuit 301 Output Shaft Torque 301 ′ Conventional Output Shaft Torque 302 Engine Speed 401 Required Deceleration 402 Corner 403 Corner Inlet 404 Corner Outlet 405 Corner R
500 Line pressure 501 Engagement clutch oil pressure 501 'Conventional engagement clutch oil pressure 502 Engagement clutch oil pressure 502 for next shift 502' Engagement clutch oil pressure 510 for next shift Possible lower limit pressure 601 Output shaft torque 601 'Conventional output shaft torque 700 Line pressure 701 Engagement side clutch hydraulic pressure 701' Conventional engagement side clutch hydraulic pressure 710 Lower limit pressure at which a shift stage can be secured a Accelerator off point c Corner Vreq Target turning vehicle speed L1 Brake braking force signal line L Control execution boundary line SG1 Brake braking force signal SG2 Brake control signal

Claims (9)

A control device for an automatic transmission,
At the end stage of the shift of the automatic transmission, the hydraulic pressure to the friction engagement device of the automatic transmission required to maintain the shift stage after the shift is lower than the hydraulic pressure based on the line pressure A control device for an automatic transmission, characterized in that The control device for an automatic transmission according to claim 1,
The hydraulic pressure to the friction engagement device is set between the line pressure and the hydraulic pressure required to maintain the engagement state of the friction engagement device required to maintain the shift speed. A control device for an automatic transmission, characterized in that The control device for an automatic transmission according to claim 1,
The hydraulic pressure to the friction engagement device is controlled so that the difference in rotational speed of the friction engagement device required to maintain the shift speed is approximately a predetermined rotational speed difference. Transmission control device. The control device for an automatic transmission according to any one of claims 1 to 3,
Means for predicting whether the need for the next shift occurs within a predetermined period after the shift;
When the need for the next shift is expected to occur within the predetermined period, the shift stage after the shift is compared with the case where the need for the next shift is not expected to occur within the predetermined period. A control device for an automatic transmission, characterized in that a hydraulic pressure to the friction engagement device required for maintaining is lowered. The control apparatus for an automatic transmission according to any one of claims 1 to 4,
Means for detecting that the running state of the vehicle is in a state in which the vehicle behavior is likely to be affected;
When it is detected that the traveling state of the vehicle is likely to affect the vehicle behavior, compared to the case where it is not detected that the traveling state of the vehicle is likely to affect the vehicle behavior, A control device for an automatic transmission, characterized in that a hydraulic pressure to the friction engagement device required to maintain a gear position after the gear shift is low. The control device for an automatic transmission according to claim 5,
When it is detected that the traveling state of the vehicle is likely to affect the vehicle behavior, compared to the case where it is not detected that the traveling state of the vehicle is likely to affect the vehicle behavior, A control device for an automatic transmission, characterized in that handling relating to execution of the shift is changed. The control apparatus for an automatic transmission according to claim 6,
The state in which the traveling state of the vehicle is likely to affect the vehicle behavior includes a state in which the vehicle enters a corner and a state in which the tire of the vehicle has a slip of a predetermined value or more,
When the state where the vehicle is entering the corner is detected and the state where the vehicle tires are slipping more than a predetermined value is not detected, if the shift is before the end stage, the shift is not performed. A control device for an automatic transmission, characterized by being discontinued. The control apparatus for an automatic transmission according to claim 6,
The state in which the traveling state of the vehicle is likely to affect the vehicle behavior includes a state in which the vehicle enters a corner and a state in which the tire of the vehicle has a slip of a predetermined value or more,
If the vehicle is entering a corner and the vehicle's tires are detected to be slipping more than a predetermined value, the shift may be performed before or after the shift enters the end stage. A control device for an automatic transmission, wherein The control apparatus for an automatic transmission according to claim 6,
The state in which the traveling state of the vehicle is likely to affect the vehicle behavior includes a state in which the vehicle enters a corner and a state in which the tire of the vehicle has a slip of a predetermined value or more,
When the state in which the vehicle enters the corner is detected, and the state in which the tire of the vehicle has slippage of a predetermined value or more is not detected, whether before or after the shift enters the end stage, The control apparatus for an automatic transmission, wherein the shift is stopped.

Images