JP2005201422A - Vehicle deceleration control device - Google Patents

Abstract

Provided is a vehicle deceleration control device that performs appropriate deceleration control when a manual shift is performed during tracking control or when a tracking control condition is satisfied during manual shifting.
Deceleration of a vehicle that performs deceleration control by an operation of a braking device that generates a braking force on the vehicle and a shift operation that shifts the transmission of the vehicle to a relatively low speed gear ratio or gear ratio. When the deceleration control based on a vehicle traveling environment including at least one of a road gradient and a road shape on which the vehicle travels, or the deceleration control with manual shift, is performed. When a condition for performing the deceleration control based on the distance between the vehicle and an obstacle including a preceding vehicle ahead of the vehicle is satisfied, the vehicle travel is performed without performing the deceleration control based on the distance. Control is performed such that the deceleration control based on the environment or the deceleration control with manual shifting is performed.
[Selection] Figure 1

Description

  The present invention relates to a deceleration control device for a vehicle, and more particularly to deceleration of a vehicle by an operation of a braking device that generates a braking force on the vehicle and an operation of shifting an automatic transmission to a relatively low speed gear ratio or gear ratio. The present invention relates to a vehicle deceleration control device that performs control.

  As a technique for cooperatively controlling an automatic transmission and a brake, there is known a technique for operating a brake when the automatic transmission is manually shifted in a direction in which an engine brake is applied. As such an automatic transmission and brake cooperative control device, there is a technique disclosed in Japanese Patent No. 2503426 (Patent Document 1).

  In the above-mentioned Patent Document 1, in the case of a manual shift for operating an engine brake in an automatic transmission (A / T), an idle running in a neutral state from the start of the shift until the actual engine brake is activated is described as a brake of the vehicle. Techniques for preventing and activating are disclosed.

  Moreover, it is described in the said patent document 1 as follows. The engine negative torque peak value at the time of shifting determined from the type of shifting and the vehicle speed, etc., from the manual downshift gear shifting command time to the predetermined time or until the engine brake begins to work (the negative torque of the A / T output shaft increases) In response to this, the brake of the vehicle is operated. Since the brake of the vehicle is operated with a braking force corresponding to the negative A / T output shaft torque at the time of manual shift during the manual shift, the braking force is applied to the vehicle according to the magnitude of the engine brake during the manual shift. . A stable braking force is applied to the vehicle from the time when the manual shift is performed to the time when the gear shift is completed, and a highly responsive and stable braking force is obtained during the manual shift. During the neutral state of the automatic transmission, the brake of the vehicle is operated and the engine brake is not suddenly applied, so that the fluctuation of the braking force is reduced.

  On the other hand, deceleration control is known that performs downshifting of an automatic transmission and operation of a braking device so that the distance between the host vehicle and the preceding vehicle does not become a predetermined value or less. Japanese Patent Laid-Open No. 2001-30792 (Patent Document 2) discloses that when the target deceleration cannot be achieved only by fully closing the throttle valve and shifting down, the throttle valve is fully closed and the automatic brake is operated without performing the shifting down. Achieves target deceleration, avoids shift shock due to downshift, improves ride comfort, and when target deceleration is smaller than the predetermined deceleration, throttle valve fully closed, shift down execution and automatic It is described that the brake is simultaneously activated.

  In Japanese Patent No. 3123384 (Patent Document 3), the speed reduction control by shifting to the low speed stage of the transmission, which is performed when the inter-vehicle distance is reduced, is described in the transmission of the transmission when the inter-vehicle distance is further reduced. When the deceleration control by the braking of the wheel, which is performed together with the shift to the low speed stage, is started between the start of the deceleration control by the shift to the low speed stage of the transmission and the elapse of a predetermined time, the release means cancels it. Thus, it is disclosed that the vehicle travels satisfactorily while being decelerated and controlled only by braking the wheels without deteriorating the driving feeling.

Japanese Patent No. 2503426 JP 2001-30792 A Japanese Patent No. 3123384

  By the way, there is a difference in the control logic between the technology for operating the brakes at the time of manual downshifting and the technology for simultaneously executing the shift control and the brake control for follow-up control (inter-vehicle distance control). Therefore, there is a problem of how to control when the manual shift is performed during the follow-up control or when the follow-up control condition is satisfied during the manual shift.

  An object of the present invention is a deceleration control device that performs deceleration control by control of a braking device that generates braking force on a vehicle and shift control that shifts an automatic transmission to a relatively low speed gear ratio or gear ratio, An object of the present invention is to provide a vehicle deceleration control device that performs appropriate deceleration control when a manual shift is performed during tracking control or when a tracking control condition is satisfied during manual shifting.

  The vehicle deceleration control device according to the present invention performs deceleration control by the operation of a braking device that generates a braking force on the vehicle, and a gear shifting operation that shifts the transmission of the vehicle to a relatively low speed gear ratio or gear ratio. A vehicle deceleration control device that performs relative to the driver's intention when the first deceleration control registered in advance as being a deceleration having a relatively large relationship with the driver's intention is performed. If the condition for performing the second deceleration control registered in advance as being a deceleration with a small relationship is established, the first deceleration control is performed without performing the second deceleration control. It is controlled to be performed.

  In the present invention described above, when the first deceleration control registered in advance as a deceleration having a relatively large relationship with the driver's intention is performed, the first deceleration control is prioritized, and the driver's intention The second deceleration control is not performed even if the condition for performing the second deceleration control registered in advance as a deceleration having a relatively small relationship is established. Thereby, the deceleration control in which the driver's intention is prioritized is performed. In the present invention, in the deceleration control, the operation of the braking device (brake control) and the speed change operation (speed change control) can be performed simultaneously or concurrently.

  The vehicle deceleration control device according to the present invention performs deceleration control by the operation of a braking device that generates a braking force on the vehicle, and a gear shifting operation that shifts the transmission of the vehicle to a relatively low speed gear ratio or gear ratio. A vehicle deceleration control device that performs relative deceleration with respect to the driver's intention when the second deceleration control registered in advance as being a deceleration having a relatively small relationship with the driver's intention is performed. When the condition for performing the first deceleration control registered in advance as the deceleration having a large relationship with the above is satisfied, the braking characteristic is changed from the braking force generated by the second deceleration control. It is characterized by being controlled by.

  In the present invention described above, when the second deceleration control registered in advance as a deceleration having a relatively small relationship with the driver's intention is performed, the deceleration having a relatively large relationship with the driver's intention is performed. If the condition for performing the first deceleration control registered in advance is satisfied, priority is given to the intention of deceleration based on the driver's intention, and the control content up to that point is changed.

  In the vehicle deceleration control apparatus according to the present invention, the first deceleration control may be the deceleration control based on a vehicle traveling environment including at least one of a road gradient and a road shape on which the vehicle travels, or a manual shift. And the second deceleration control is the deceleration control based on a distance between the vehicle and an obstacle including a preceding vehicle ahead of the vehicle.

  In the vehicle deceleration control device according to the present invention, the change of the braking characteristic is characterized by changing a ratio of a temporal change in the target deceleration of the second deceleration control.

  In the present invention, when the condition for performing the first deceleration control registered in advance as the deceleration having a relatively large relationship with the driver's intention is satisfied, the gradient of the target deceleration is increased, It is possible to give a sense of response to the driver.

  In the vehicle deceleration control apparatus according to the present invention, the change in the braking characteristic may be performed by using the braking force generated by the deceleration control after the change without performing feedback control with respect to the target deceleration of the second deceleration control. It is characterized by changing to a value larger than the braking force corresponding to the target deceleration of the second deceleration control.

  In the present invention, when the condition for performing the first deceleration control registered in advance as a deceleration having a relatively large relationship with the driver's intention is satisfied, the operation amount of the braking device is changed to a large value. can do. Responsiveness is higher than when changing the target deceleration by feedback control.

  In the vehicle deceleration control apparatus according to the present invention, when the maximum value of the target deceleration by the first deceleration control is larger than the maximum value of the target deceleration by the second deceleration control, the second deceleration control is performed. The maximum value of the target deceleration by the deceleration control after the change is larger than the maximum value of the target deceleration.

  In the present invention, the maximum value of the target deceleration of the first deceleration control registered in advance as a deceleration having a relatively large relationship with the driver's intention can be set as the new target deceleration.

  In the vehicle deceleration control device according to the present invention, the braking device is at least one of means for stopping rotation of the wheels of the vehicle and means for generating power using the rotational force of the wheels. It is said.

(1) In the present invention, the brake and the automatic transmission are cooperatively controlled during follow-up traveling, manual shift, and shift point control by corner R or road gradient. In manual shift or gear shift by corner R or road gradient. When the execution condition of the follow-up control is satisfied during the point control, this is ignored and the manual shift or the shift point control by the corner R or the road surface gradient is continued, and the manual shift, the corner R or the road surface gradient is continued during the follow-up control. When the shift point control is performed, the control device changes the control content up to that point.

(2) The apparatus according to (1), wherein the initial deceleration gradient is changed when a condition for shift point control by manual shift and corner R or road gradient during tracking control is satisfied.
(3) The device according to (1), wherein the brake feedback control is interrupted and the brake pressure is increased when the conditions of shift point control by manual shift and corner R or road surface gradient during follow-up control are satisfied.
(4) A device that increases and changes the maximum target deceleration in the case of a shift in which engine braking force exceeding the maximum target deceleration is obtained when the conditions of manual shift during follow-up control and shift point control by corner R or road gradient are satisfied. is there.

  According to the vehicle deceleration control apparatus of the present invention, appropriate deceleration control is performed when a manual shift is performed during the follow-up control or when a follow-up control condition is satisfied during the manual shift.

  Hereinafter, an embodiment of a vehicle deceleration control device of 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 11. The present embodiment relates to a vehicle deceleration control device that performs cooperative control of a braking device and an automatic transmission.

  In this specification, the manual downshift means a downshift that is manually performed when the driver desires an increase in engine braking force. In addition, the shift point control is based on information such as traveling road information related to a road on which a vehicle including a corner R in front of the vehicle and a road surface gradient travels and road traffic information related to traffic on a road including a distance between vehicles. Shifting.

  First, the basic control flow of the first embodiment will be described with reference to FIG.

[Step S1]
First, in step S1, it is determined whether or not shift point control based on the inter-vehicle distance (so-called follow-up control) is being executed. As a result of the determination, when it is determined that the follow-up control is being executed, the process proceeds to step S2, and when it is determined that it is not, the process proceeds to step S5. In the follow-up control of the present embodiment, the brake control and the shift control are executed simultaneously in cooperation (details will be described later).

[Step S2]
Next, in step S2, the presence or absence of manual downshift determination or shift point control execution determination based on corner R or road surface gradient is determined. As a result of the determination, if manual downshift determination or shift point control execution determination based on corner R or road surface gradient is made, the process proceeds to step S3, and if not, the process proceeds to step S4. It should be noted that each of the deceleration control at the time of manual downshift and the shift point control based on the corner R and the road surface gradient of the present embodiment is executed simultaneously in cooperation with the brake control and the shift control (details will be described later). To do).

[Step S3]
In step S3, the control content is changed (details will be described later). After step S3, this control flow is reset.

[Step S4]
In step S4, the shift point control based on the inter-vehicle distance is continued. After step S4, this control flow is reset.

[Step S5]
In step S5, it is determined whether or not the control associated with the manual downshift or the shift point control based on the corner R or the road surface gradient is being executed. As a result of the determination, if it is determined that the control associated with the manual downshift or the shift point control based on the corner R or the road surface gradient is being executed, the process proceeds to step S6. Reset.

[Step S6]
In step S6, it is determined whether or not an execution condition for the shift point control based on the inter-vehicle distance is satisfied. As a result of the determination, the process proceeds to step S7 regardless of whether it is determined that the execution condition of the shift point control based on the inter-vehicle distance is satisfied or not.

[Step S7]
In step S7, the control associated with the manual downshift or the shift point control based on the corner R or the road surface gradient is continued. After step S7, this control flow is reset.

  As shown in steps S5 to S7, when the control associated with the manual downshift or the shift point control based on the corner R or the road surface gradient is being executed (step S5-Y), the shift point control based on the inter-vehicle distance is performed. Even if the execution condition is satisfied (steps S6-Y, S6-N), the control associated with the manual downshift or the shift point control based on the corner R or road gradient is prioritized and continued as it is, and the shift point based on the inter-vehicle distance is continued. Control is not executed (step S7). After the control associated with the manual downshift or the shift point control based on the corner R or road gradient (step S5-N after resetting the control flow), whether or not the follow-up control condition is satisfied as usual. Is determined (not shown), and whether or not the follow-up control is executed is determined according to the determination result (not shown).

  As shown in the above steps S1 to S3, when manual downshift determination or shift point control execution determination based on corner R or road gradient is made during execution of follow-up control (step S2-Y), the determination is made. Prioritize and change the control content up to that point (step S3). This is because priority is given to deceleration based on the driver's intention, so that the driver does not feel uncomfortable.

  Manual downshift is a shift (significant shift) based on the driver's intention. On the other hand, the follow-up control is a control in which the engine braking force when the accelerator is off (or when the brake is on) is supplementarily increased, and is not directly based on the driver's intention. This is a control of Kuroko meaning in that the driver (person) is assisted so as to achieve the target inter-vehicle distance and relative vehicle speed. From this, when manual downshift determination is made during the execution of the follow-up control, the deceleration based on the driver's intention is prioritized and the control content up to that point is changed (step S3).

  Here, in this embodiment, the shift point control based on the corner R and the road surface gradient is handled in the same manner as the manual downshift (steps S2, S5, and S7). The driver may perform a trigger operation such as turning off the accelerator at a predetermined position on the road surface before the corner or on the slope based on his / her will, and these are regarded as deceleration by the driver's intention. Therefore, it is handled in the same way as manual downshift.

  That is, in a control circuit ROM (see reference numeral 133 in FIG. 1) described later, manual downshift and shift point control based on corner R and road surface gradient are relatively slow in relation to the driver's intention. 1 (refer to FIGS. 5-1 to 5-3) is registered in advance. On the other hand, the program pre-registered in the ROM of the control circuit is that the follow-up control (shift point control based on the inter-vehicle distance) is a deceleration (second deceleration control) that has a relatively small relationship with the driver's intention. Is described as a premise.

  In the flowchart of FIG. 1 described above, step S6 is shown for convenience of explanation to clarify the features of the present embodiment. However, in the actual control process, step S6 may not be executed. Good. That is, if it is determined in step S5 that the control associated with the manual downshift or the shift point control based on the corner R or the road surface gradient is being executed (step S5-Y), the step of step S6 is not executed. Then, the control associated with the manual downshift or the shift point control based on the corner R or the road surface gradient can be continued (step S7).

  Next, the configuration of the present embodiment will be described with reference to FIGS.

  In FIG. 2, reference numeral 10 denotes an automatic transmission, 40 denotes an engine, and 200 denotes a brake device. The automatic transmission 10 is capable of five-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 input shaft rotation speed sensor 124 detects the rotation speed of the input shaft (not shown) of the automatic transmission 10.

  The acceleration sensor 90 detects vehicle deceleration (deceleration acceleration). The manual shift determination unit 95 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 relative vehicle speed detection / estimation unit 97 detects or estimates the relative vehicle speed between the host vehicle and the preceding vehicle. The inter-vehicle distance measuring unit 101 includes 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 preceding vehicle.

  The corner measurement / estimation unit 119 determines whether there is a corner in front of the vehicle based on road shape information obtained from a car navigation system mounted on the vehicle, a captured image of a camera mounted in front of the vehicle, and the like. Measure or estimate size.

  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 control circuit 130 inputs signals indicating detection results of the throttle opening sensor 114, the engine speed sensor 116, the vehicle speed sensor 122, the shift position sensor 123, and the acceleration sensor 90, and changes the switching state of the pattern select switch 117. A signal indicating a measurement result by the inter-vehicle distance measuring unit 101, a signal indicating the necessity of shifting from the manual shift determining unit 95, and a relative vehicle speed detecting / estimating unit 97. And the signal which shows the result of detection or estimation by each of the corner measurement / estimation unit 119 is inputted.

  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, an inter-vehicle distance measuring unit 101, a relative vehicle speed detecting / estimating unit 97, a corner measuring / estimating unit. 119 and a signal from each of the manual shift determination unit 95 are input. 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 ROM 133 stores in advance the operations (control steps) shown in the flowcharts of FIGS. 5-1 to 5-3, and also includes a shift map and a shift control operation for shifting the shift stage of the automatic transmission 10 ( (Not shown) are stored. The control circuit 130 shifts the automatic transmission 10 based on various input control conditions.

  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 wheel cylinders 208, 209, 210, and 211 provided on the wheels 204, 205, 206, and 207 of the vehicle, respectively. Each wheel cylinder 208, 209, 210, 211 controls the braking force of the corresponding wheel 204, 205, 206, 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.

  Next, the configuration of the automatic transmission 10 is shown in FIG. In FIG. 3, the output of the engine 40 as a driving source for traveling constituted by an internal combustion engine is input to the automatic transmission 10 through an input clutch 12 and a torque converter 14 as a fluid power transmission device. Is transmitted to the drive wheel via the differential gear unit and the axle. Between the input clutch 12 and the torque converter 14, a first motor generator MG1 that functions as an electric motor and a generator is disposed.

  The torque converter 14 is directly connected between the pump impeller 20 connected to the input clutch 12, the turbine impeller 24 connected to the input shaft 22 of the automatic transmission 10, and the pump impeller 20 and the turbine impeller 24. And a stator impeller 30 that is prevented from rotating in one direction by a one-way clutch 28.

  The automatic transmission 10 includes a first transmission unit 32 that switches between two stages of high and low, and a second transmission unit 34 that can switch between a reverse transmission stage and four forward stages. The first transmission unit 32 is supported by the sun gear S0, the ring gear R0, and the carrier K0 so as to be rotatable, and the planetary gear P0 includes a planetary gear P0 meshed with the sun gear S0 and the ring gear R0, and the sun gear S0 and the carrier. A clutch C0 and a one-way clutch F0 provided between K0 and a brake B0 provided between the sun gear S0 and the housing 38 are provided.

  The second transmission unit 34 is supported by the sun gear S1, the ring gear R1, and the carrier K1 so as to be rotatable, and the first planetary gear device 40 including the planetary gear P1 meshed with the sun gear S1 and the ring gear R1, and the sun gear S2, A second planetary gear unit 42 including a planetary gear P2 that is rotatably supported by the ring gear R2 and the carrier K2 and meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3, and the carrier K3 is rotatable. And a third planetary gear unit 44 comprising a planetary gear P3 supported and meshed with the sun gear S3 and the ring gear R3.

  The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2, and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 120c. Further, the ring gear R2 is integrally connected to the sun gear S3 and the intermediate shaft 48. A clutch C1 is provided between the ring gear R0 and the intermediate shaft 48, and a clutch C2 is provided between the sun gear S1, the sun gear S2, and the ring gear R0. A band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2 is provided in the housing 38. A one-way clutch F1 and a brake B2 are provided in series between the sun gear S1 and sun gear S2 and the housing 38. The one-way clutch F <b> 1 is engaged when the sun gear S <b> 1 and the sun gear S <b> 2 try to reversely rotate in the direction opposite to the input shaft 22.

  A brake B3 is provided between the carrier K1 and the housing 38, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 38. The one-way clutch F2 is engaged when the ring gear R3 tries to rotate in the reverse direction.

  In the automatic transmission 10 configured as described above, for example, according to the operation table shown in FIG. 4, it is switched to one of the reverse gears and the five forward gears (1st to 5th) with different gear ratios. In FIG. 4, “◯” represents engagement, a blank represents release, “解放” represents engagement during engine braking, and “Δ” represents engagement not involved in power transmission. The clutches C0 to C2 and the brakes B0 to B4 are all hydraulic friction engagement devices that are engaged by a hydraulic actuator.

  Next, the operation of this embodiment will be described with reference to FIGS.

5A to 5C are flowcharts illustrating the control flow of the present embodiment.
FIG. 11 is a time chart for explaining the present embodiment. FIG. 11 shows the input rotation speed, the accelerator opening, the shift output, the brake control amount, the clutch torque, and the deceleration acceleration (G) acting on the vehicle of the automatic transmission 10. At time T0, the current deceleration (deceleration acceleration, actual vehicle deceleration) is the same as the current gear stage deceleration Gf, as indicated by reference numeral 303.

[Step SA1]
First, as shown in step SA1 in FIG. 5A, the control circuit 130 checks the flag F. Since the flag F is 0 at the beginning of this control, the process proceeds to step SA2. On the other hand, if the flag F is 1, the process proceeds to step SA11 in FIG.

[Step SA2]
In step SA2, the control circuit 130 determines whether the inter-vehicle distance between the host vehicle and the preceding vehicle is equal to or less than a predetermined value based on the signal indicating the inter-vehicle distance input from the inter-vehicle distance measuring unit 101. If it is determined in step SA2 that the inter-vehicle distance is equal to or less than the predetermined value, the process proceeds to step SA3. On the other hand, if it is not determined that the inter-vehicle distance is equal to or smaller than the predetermined value, the control flow is reset as shown in FIG.

  In the control circuit 130, instead of directly determining whether or not the inter-vehicle distance is equal to or less than a predetermined value, a parameter indicating that the inter-vehicle distance is clogged to the predetermined value or less, such as a collision time (inter-vehicle distance / relative vehicle speed), Whether the inter-vehicle distance is less than or equal to a predetermined value may be determined indirectly based on the inter-vehicle time (inter-vehicle distance / own vehicle speed), a combination thereof, and the like.

[Step SA3]
In step SA3, the control circuit 130 determines whether or not the accelerator is OFF based on the signal from the throttle opening sensor 114. If it is determined as a result of step SA3 that the accelerator is OFF, the process proceeds to step SA4. On the other hand, if it is not determined that the accelerator is in the OFF state, this control flow is reset. In FIG. 11, the fully closing operation of the accelerator is performed at time T0. Steps SA2 and SA3 are the “execution conditions for shift point control based on the inter-vehicle distance” shown in step S6 of FIG. The vehicle follow-up control is started from step SA4.

[Step SA4]
In step SA4, the target deceleration is obtained by the control circuit 130. The target deceleration is such a value (deceleration acceleration) that the relationship with the preceding vehicle becomes the target inter-vehicle distance or relative vehicle speed when deceleration control (described later) based on the target deceleration is performed on the host vehicle. As required.

  The target deceleration is obtained with reference to a target deceleration map (FIG. 6) stored in advance in the ROM 133. As shown in FIG. 6, the target deceleration is obtained based on the relative vehicle speed [km / h] and the inter-vehicle time [sec] between the host vehicle and the preceding vehicle. Here, the inter-vehicle time is the inter-vehicle distance / own vehicle speed as described above.

  In FIG. 6, for example, when the relative vehicle speed is −20 [km / h] and the inter-vehicle time is 1.0 [sec], the target deceleration is −0.20 (G). The target deceleration is set to a smaller value (so as not to decelerate) as the relationship between the host vehicle and the preceding vehicle approaches a safe relative vehicle speed or inter-vehicle distance. That is, the target deceleration is obtained as a small value on the upper right side of the target deceleration map of FIG. 6 as the distance between the host vehicle and the preceding vehicle is sufficiently secured. The higher the value, the larger the value on the lower left side of the target deceleration map.

  The target deceleration obtained in this step SA4 is the time point (step SA8) and the brake control (step SA9) before the actual execution of the shift control (step SA8) after the deceleration control start condition (steps SA2 and SA3) is satisfied ( The target deceleration at the start of deceleration control) is particularly referred to as the maximum target deceleration Gt. That is, as will be described later, since the target deceleration is set in real time even in the middle of the deceleration control, the target deceleration set after the brake control and the shift control are actually executed (during execution). In particular, the target deceleration obtained in step SA4 is referred to as the maximum target deceleration Gt. Following step SA4, step SA5 is executed.

[Step SA5]
In step SA5, a target deceleration 403 is set. Here, the target deceleration 403 is set so as to reach the maximum target deceleration Gt with a predetermined gradient α from the current deceleration 303 (current gear stage deceleration Gf) (at the start of this control: T0 in FIG. 11). Is done. The predetermined gradient α is set based on the friction coefficient μ of the road surface, the accelerator return speed at the start of this control, and the opening before the accelerator is returned. For example, the gradient (inclination) is reduced when the friction coefficient μ of the road surface is low, and the gradient is increased when the accelerator return speed or the opening before returning the accelerator is large.

  In the example of FIG. 11, as a result of setting the target deceleration 403 based on the predetermined gradient α, the target deceleration 403 reaches the maximum target deceleration Gt at time T3. A signal indicating the set target deceleration 403 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 target deceleration 403 set here is the overall target deceleration of the cooperative control of the brake device 200 and the automatic transmission 10. In the present embodiment, the actual deceleration 303 of the vehicle is controlled so as to quickly coincide with the target deceleration 403 as a result of the cooperative control, and in FIG. The target deceleration 403 is indicated by the same line.

[Step SA6]
In step SA6, the control circuit 130 obtains a target deceleration (hereinafter referred to as gear stage target deceleration Gs) by the automatic transmission 10, and based on the gear stage target deceleration Gs, shifts of the automatic transmission 10 are performed. A gear stage to be selected in the control (shift down) is determined. The shift stage to be selected, which is determined here, corresponds to a shift stage that is selected as a shift stage that matches the overall target deceleration 403 of the cooperative control. Hereinafter, the content of step SA6 will be described by dividing it into (1) and (2).

(1) First, the gear position target deceleration Gs is obtained.
The gear stage target deceleration Gs corresponds to the engine braking force (deceleration acceleration) to be obtained by the shift control of the automatic transmission 10. The gear stage target deceleration Gs is set as a value equal to or less than the maximum target deceleration Gt. The following three methods are conceivable as a method for obtaining the gear stage target deceleration Gs.

First, a first method for obtaining the shift speed target deceleration Gs will be described.
The gear stage target deceleration Gs is set as a value obtained by multiplying the maximum target deceleration Gt obtained by the target deceleration map of FIG. 6 in step SA4 by a coefficient greater than 0 and 1 or less. For example, as in the case of the above example of step SA4, when the maximum target deceleration Gt is -0.20G, for example, -0.10G, which is a value obtained by multiplying by a coefficient of 0.5, is changed. It can be set as the stage target deceleration Gs.

Next, a second method for obtaining the shift speed target deceleration Gs will be described.
A gear stage target deceleration map (FIG. 7) is registered in the ROM 133 in advance. With reference to the shift speed target deceleration map of FIG. 7, the shift speed target deceleration Gs is obtained. As shown in FIG. 7, the shift speed target deceleration Gs is obtained based on the relative vehicle speed [km / h] and the inter-vehicle time [sec] between the host vehicle and the preceding vehicle, similarly to the target deceleration 403 in FIG. It is done. For example, as in the case of the above example of step SA4, when the relative vehicle speed is −20 [km / h] and the inter-vehicle time is 1.0 [sec], −0.10 G is the gear position target. It is obtained as the deceleration Gs. As is clear from FIGS. 6 and 7, when the relative vehicle speed is large and suddenly approaches, when the inter-vehicle time is short, or when the inter-vehicle distance is short, it is necessary to make the inter-vehicle distance appropriate at an early stage. The deceleration needs to be larger. Also, from this, the lower speed stage is selected in the above situation.

Next, a third method for obtaining the shift speed target deceleration Gs will be described.
First, the engine braking force (deceleration G) when the accelerator of the current gear position of the automatic transmission 10 is OFF is obtained (hereinafter referred to as the current gear speed deceleration Gf). A current gear speed deceleration map (FIG. 8) is registered in the ROM 133 in advance. The current shift speed deceleration Gf (deceleration acceleration) is obtained by referring to the current shift speed deceleration map of FIG. As shown in FIG. 8, the current shift speed deceleration Gf is obtained based on the shift speed and the rotational speed NO of the output shaft 120 c of the automatic transmission 10. For example, when the current shift speed is 5th and the output rotational speed is 1000 [rpm], the current shift speed deceleration Gf is -0.04G.

  Note that the current shift speed deceleration Gf may be corrected by a value obtained from the current shift speed deceleration map according to various conditions such as whether the vehicle is operating an air conditioner or whether a fuel cut is performed. In addition, a plurality of current speed stage deceleration maps are prepared in the ROM 133 for each situation such as whether the vehicle is operating an air conditioner or whether a fuel cut is present, and the current speed stage deceleration used according to those situations. You may switch maps.

  Next, the shift speed target deceleration Gs is set as a value between the current shift speed deceleration Gf and the maximum target deceleration Gt. That is, the shift speed target deceleration Gs is obtained as a value that is greater than the current shift speed deceleration Gf and less than or equal to the maximum target deceleration Gt. FIG. 9 shows an example of the relationship between the shift speed target deceleration Gs, the current shift speed deceleration Gf, and the maximum target deceleration Gt.

The gear stage target deceleration Gs is obtained by the following equation.
Shift target deceleration Gs = (maximum target deceleration Gt−current shift speed deceleration Gf) × coefficient + current shift speed deceleration Gf
In the above formula, the coefficient is a value greater than 0 and less than or equal to 1.

  In the above example, the maximum target deceleration Gt = −0.20 G, the current gear stage deceleration Gf = −0.04 G, and when the coefficient is set to 0.5 and calculated, the gear stage target deceleration Gs is −0. .12G.

  As described above, a coefficient is used in the first and third methods of determining the gear position target deceleration Gs. However, the value of the coefficient is not a value that is theoretically determined, and can be set as appropriate from various conditions. Conformity value. That is, for example, in a sports car, a relatively large deceleration is preferred when decelerating, and therefore the value of the coefficient can be set to a large value. Further, even for the same vehicle, the value of the coefficient can be variably controlled according to the vehicle speed and the gear position. The vehicle responsiveness to the driver's operation is improved, the so-called sport mode intended for sharp vehicle driving, and the vehicle's responsiveness to the driver's operation is relaxed, so that the vehicle travels with low fuel consumption. In the case of a vehicle in which a mode called an intended so-called luxury mode or economy mode can be selected, the gear stage target deceleration Gs is set so that a larger gear stage change occurs than in the luxury mode or economy mode when the sport mode is selected.

  After the speed target deceleration Gs is obtained in step SA6, it is not set again until the deceleration control is completed. That is, after the shift speed target deceleration Gs is obtained at the start time of the deceleration control (the time point before the brake control (step SA9) and the shift control (step SA8) are actually executed), the deceleration control is finished. It is set as the same value until. As shown in FIG. 9, the shift speed target deceleration Gs (value indicated by a broken line) is the same value even if time elapses.

(2) Next, based on the shift speed target deceleration Gs obtained in (1) above, the shift speed to be selected in the shift control of the automatic transmission 10 is determined. Vehicle characteristic data indicating the deceleration G for each vehicle speed at each shift speed when the accelerator is OFF as shown in FIG. 10 is registered in advance in the ROM 133.

  As in the above example, assuming that the output rotational speed is 1000 [rpm] and the gear stage target deceleration Gs is −0.12 G, the output rotational speed is 1000 [rpm] in FIG. It can be seen that the speed stage corresponding to the vehicle speed at the time of the above and the speed stage closest to the speed stage target deceleration Gs of −0.12G is the fourth speed. As a result, in the case of the above example, in step SA6, the shift speed to be selected is determined to be the fourth speed.

  In this example, the speed stage closest to the speed stage target deceleration Gs is selected as the speed stage to be selected, but the speed stage to be selected is equal to or lower than the speed stage target deceleration Gs. A gear stage that is a deceleration and that is closest to the gear stage target deceleration Gs may be selected. Step SA6 is executed after step SA6.

[Step SA7]
In step SA7, the control circuit 130 determines whether or not the accelerator is OFF and the brake is OFF. In step SA7, the brake being in the OFF state means that the brake is in the OFF state without any operation of the brake pedal (not shown) by the driver, and is input via the brake control circuit 230. The determination is made based on the output of a brake sensor (not shown). If it is determined in step SA7 that the accelerator is OFF and the brake is OFF, the process proceeds to step SA8. On the other hand, if it is not determined that the accelerator is OFF and the brake is OFF, the process proceeds to step SA15.

  At time T0 in FIG. 11, the accelerator is OFF (accelerator opening is fully closed) as indicated by reference numeral 301 and the brake is OFF (brake force is zero) as indicated by reference numeral 302. is there.

[Step SA8]
In step SA8, the shift control is started by the control circuit 130. That is, the shift control is performed to the gear position to be selected (in the above example, the fourth speed) determined in step SA6. 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 response to the downshift command, the solenoid valve driving units 138a to 138c energize or de-energize the solenoid valves 121a to 121c. Thereby, in the automatic transmission 10, a shift (in the above example, a shift to the fourth speed) instructed by the downshift command is executed. A downshift command based on the shift control in step SA8 is output at time T0.

  At time T0, as shown by reference numeral 304, when a downshift command by shift control is output to the automatic transmission 10 (step SA8), the type of shift (for example, 4th speed → 3rd speed, 3rd speed) from that time T0. → The shift of the automatic transmission 10 actually starts at time T2 after the time ta determined based on the combination of the shift speed before the shift and the shift speed after the shift (such as the second speed). Thus, the clutch torque 408 starts to increase, and the deceleration 402 due to the shift of the automatic transmission 10 starts to increase. Following step SA8, step SA9 is executed.

  In step SA3, the example in which the accelerator fully closing operation is performed at the time point T0 has been described. However, it may be performed before the time point T0 when the step SA8 is performed. In the example of FIG. 11, the signal is generated based on a signal indicating the necessity of downshifting output from the manual shift determining unit 95 or a measurement / estimation result from the corner measurement / estimation unit 119 or the road gradient measurement / estimation unit 118. With respect to the signal indicating the necessity for downshifting, the control circuit 130 shows a case where it is determined that there is a need for downshifting at the time T0.

[Step SA9]
In step SA9, the brake control circuit 230 starts brake control. That is, the brake is feedback-controlled so that the current deceleration 303 becomes the target deceleration 403 set in step SA5. As indicated by reference numeral 302, the brake feedback control is started at time T0 when the downshift command by the shift control is output.

  That is, a signal indicating the target deceleration 403 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 from the time T0. 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 pressure 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 brake force (brake control amount 302) as instructed in the brake control signal SG2 is controlled. ).

  In the feedback control of the brake device 200 in step SA9, the target value is the target deceleration 403, the control amount is the actual deceleration of the vehicle, and the control target is the brake (braking devices 208, 209, 210, 211), The operation amount is the brake control amount 302, and the disturbance is mainly the deceleration 402 due to the shift of the automatic transmission 10. The actual deceleration of the vehicle is detected by the acceleration sensor 90.

  That is, in the brake device 200, the brake braking force (brake control amount 302) is controlled so that the actual deceleration 303 of the vehicle becomes the target deceleration 403. That is, the brake control amount 302 is set so as to generate a deceleration that is insufficient for the deceleration 402 due to the shift of the automatic transmission 10 when the target deceleration 403 is generated in the vehicle.

  In the example of FIG. 11, the deceleration 402 by the automatic transmission 10 is zero from the time T0 when the downshift command by the shift control is output until the time T2 at which the shift of the automatic transmission 10 is actually started. The brake control amount 302 is set so that all decelerations of the target deceleration 403 are generated by the brake. The shift of the automatic transmission 10 is started from time T2, and the brake control amount 302 decreases as the deceleration 402 by the automatic transmission 10 increases.

  Thus, as described above, the brake device 200 according to the present embodiment is based on the shift to the gear position (downshift destination corresponding to the downshift command) suitable for the target deceleration (403, including reference numeral 403a described later). Complementing the difference between the deceleration and the target deceleration (403, including reference numeral 403a described later), as a result of the overall cooperative control of the brake device 200 and the automatic transmission 10, the target deceleration (403, reference numeral 403a described later) is obtained. Feedback control is performed so as to act on the vehicle. As a result of the feedback control of the brake, the current deceleration 303 increases while following the target deceleration (403, including a reference numeral 403a described later).

  Note that the brake force 302 by the brake control may be determined in consideration of a shift differential value of the input shaft rotation speed of the automatic transmission 10 and a shift inertia torque determined by inertia.

  Here, the “target deceleration” in step SA9 includes both the target deceleration 403 set in step SA5 and the target deceleration 403a changed in step SA22 described later or set in steps SA26 and SA27. The brake control of step SA9 is continuously executed until the brake control is finished in step SA15. Following step SA9, step SA10 is executed.

[Step SA10]
In step SA10, the control circuit 130 sets the flag F to 1. Following step SA10, step SA11 of FIG. 5-2 is performed.

[Step SA11]
In step SA11, the control circuit 130 determines the presence or absence of manual shift determination (command) or shift point control execution determination (command) based on the corner R or road surface gradient. Here, whether or not a signal indicating the necessity of shifting (downshifting) the gear position of the automatic transmission 10 to the relatively low speed side is output from the manual shift determination unit 95, or a corner measurement / estimation unit 119 or based on the measurement / estimation result from the road gradient measurement / estimation unit 118, it is determined whether or not a signal indicating the necessity of shifting the gear position of the automatic transmission 10 to the relatively low speed side is generated. The The signal includes data indicating the downshift destination gear.

  This step SA11 corresponds to step S2 in FIG. In each of steps SA11, SA23, SA25 in FIG. 5-2 and the shift output in FIG. 11, only “manual shift” is described. However, as described in the present embodiment, not only “manual shift” but also “ This includes the case of “shift point control based on corner radius or road gradient”.

  When a signal indicating the necessity for downshifting is output from the manual shift determining unit 95, or the necessity for downshifting based on the measurement / estimation results from the corner measurement / estimation unit 119 or the road gradient measurement / estimation unit 118 Is generated as a joint target between the brake device 200 and the automatic transmission 10 described above, the deceleration obtained by the downshift to the downshift destination included in the signal is generated. This means that the “target deceleration 403, 403a” is set. Further, in this case, it means that the driver has set the downshift destination gear included in the signal as “a gear suitable for the target deceleration 403, 403a”.

  In FIG. 11, the determination in step SA11 is performed at time T1. As a result of the determination in step SA11, when it is determined that a signal indicating the necessity for downshifting is output from the manual shift determining unit 95, or from the corner measurement / estimation unit 119 or the road gradient measurement / estimation unit 118 If a signal indicating the need for downshifting is generated based on the measurement / estimation result (step SA11-Y), the process proceeds to step SA22. On the other hand, if not so determined (step SA11-N), the process proceeds to step SA12.

  In step SA11, output of a signal indicating the necessity of downshift from the manual shift determination unit 95, or downshift based on the measurement / estimation result from the corner measurement / estimation unit 119 or the road gradient measurement / estimation unit 118 is necessary. When the signal indicating the sex is not generated (step SA11-N), the follow-up control is continued (steps SA12 to SA20, corresponding to step S4 in FIG. 1).

  On the other hand, in step SA11, a downshift based on the output of a signal indicating the necessity of downshifting from the manual shift determination unit 95 or the measurement / estimation result from the corner measurement / estimation unit 119 or the road gradient measurement / estimation unit 118 is performed. Is generated (step SA11-Y), the control content is changed (steps SA22 to SA27, corresponding to step S3 in FIG. 1).

[Step SA12]
In step SA12, the control circuit 130 determines whether or not the current deceleration 303 is a deceleration at the end point of the set target deceleration 403. As a result of the determination, if it is determined that the current deceleration 303 is the deceleration at the end point of the set target deceleration 403, the process proceeds to step SA13. On the other hand, if it is not determined that the current deceleration 303 is the end point of the set target deceleration 403, the process returns to step SA9. Until the time point T3 in FIG. 11, the current deceleration 303 has not reached the deceleration at the end point of the set target deceleration 403 (here, the maximum target deceleration Gt). The brake feedback control is continued. Following step SA12, step SA13 is performed.

[Step SA13]
In step SA13, the target deceleration 403 is set again. The control circuit 130 sets the target deceleration 403 with reference to the target deceleration map (FIG. 6) as in step SA4. As described above, the target deceleration 403 is set based on the relative vehicle speed and the inter-vehicle distance, and when the deceleration control (both the shift control and the brake control) starts, the relative vehicle speed and the inter-vehicle distance also change. The target deceleration 403 corresponding to is set in real time.

  When the target deceleration 403 is set in real time in step SA13, the braking force 302 is set so that the current deceleration 303 becomes the target deceleration 403 by the feedback control of the brake started in step SA9 and continuing. Given.

  The operation for obtaining the target deceleration 403 in step SA13 is continuously performed until the brake control is finished in step SA15. As will be described later, the brake control is continued until the current deceleration 303 coincides with the shift speed target deceleration Gs (more precisely, the final deceleration Ge obtained by shifting) (steps SA14 and SA15). As described above, the current deceleration 303 is controlled so as to coincide with the target deceleration 403 (steps SA9 and SA12). As a result, the operation of setting the target deceleration 403 in step SA13 is the setting. The obtained target deceleration 403 is continued until it coincides with the gear stage target deceleration Gs (Ge) (at time T6 in FIG. 11, the target deceleration 403 coincides with the gear stage target deceleration Ge).

  At the time of step SA13, the vehicle speed of the host vehicle is lower than the time of step SA4 before the start of the deceleration control by the amount that the deceleration control has already been performed. Therefore, in step SA13, the target deceleration 403 that is set to achieve the target inter-vehicle distance and relative vehicle speed is usually smaller than the maximum target deceleration Gt obtained in step SA4.

  At times T3 to T6 in FIG. 11, the operation of “setting the target deceleration 403 in real time and applying the braking force 302 by feedback control so that the current deceleration 303 matches the target deceleration 403” is repeated. However, as a result of continuing the brake control during that time, the target deceleration 403 that is repeatedly set in step SA13 becomes substantially gradually smaller, and is given by the feedback control of the brake control according to the decrease in the value of the target deceleration 403. The brake force 302 to be applied is also gradually reduced, and the current deceleration 303 is substantially gradually decreased while substantially matching the target deceleration 403. Following step SA13, step SA14 is executed.

[Step SA14] and [Step SA15]
In step SA14, the control circuit 130 determines whether or not the current deceleration 303 matches the gear position target deceleration Gs (Ge). As a result of the determination, if it is determined that the current deceleration 303 coincides with the gear stage target deceleration Gs (Ge) (step SA14-Y), the brake control ends (step SA15). The end of the brake control is transmitted to the brake control circuit 230 by the brake braking force signal SG1. On the other hand, if the current deceleration 303 does not match the gear stage target deceleration Gs (Ge) (step SA14-N), the brake control is not terminated. Since the current deceleration 303 coincides with the shift speed target deceleration Gs (Ge) at time T6 in FIG. 11, the braking force 302 applied to the vehicle becomes zero (end of brake feedback control).

[Step SA16]
In step SA16, the control circuit 130 determines whether or not the accelerator is turned on. If the accelerator is turned on, the process proceeds to step SA17. If the accelerator is not turned on, the process proceeds to step SA20. In the example of FIG. 11, the description of the state when the accelerator is turned on is omitted.

[Step SA17]
In step SA17, the return timer starts. After step SA17, the process proceeds to step SA18. The return timer is provided in the CPU 131 of the control circuit 130 (not shown).

[Step SA18]
In step SA18, the control circuit 130 determines whether or not the count value of the return timer is greater than or equal to a predetermined value. If the count value is not greater than or equal to the predetermined value, the process returns to step SA16. If the count value is equal to or greater than the predetermined value, the process proceeds to step SA19.

[Step SA19]
In step SA19, the shift control (downshift control) by the control circuit 130 is completed, and the gear returns to the shift stage determined based on the accelerator opening and the vehicle speed according to the normal shift map (shift line) stored in the ROM 133 in advance. . Following step SA19, step SA21 is performed.

[Step SA20]
In step SA20, the control circuit 130 determines whether the inter-vehicle distance has exceeded a predetermined value. This step SA20 corresponds to step SA2. If it is determined that the inter-vehicle distance exceeds the predetermined value, the process proceeds to step SA19. If it is not determined that the inter-vehicle distance exceeds the predetermined value, the process returns to step SA16. In the example of FIG. 11, the description of the state when the inter-vehicle distance exceeds a predetermined value is omitted.

[Step S21]
In step SA21, the control circuit 130 resets the flag F to 0. When step SA21 is performed, this control flow is reset.

[Step SA22]
In step SA22 of FIG. 5B, the control circuit 130 changes the gradient of the target deceleration 403. In FIG. 11, the target deceleration changed at step SA22 is indicated by reference numeral 403a. The target deceleration 403a is set so as to reach the maximum target deceleration Gt with a gradient larger than the gradient α of the target deceleration 403.

  In step SA22, based on the output of a signal indicating the necessity of downshifting from the manual shift determination unit 95 or the measurement / estimation result from the corner measurement / estimation unit 119 or the road gradient measurement / estimation unit 118 at time T1. When it is determined that a signal indicating the necessity for downshifting has been generated (step SA11-Y), the gradient of the target deceleration 403a is changed at that time T1. In step SA22, in response to the setting of the new target deceleration 403a, the brake control amount is increased by the feedback control of the brake that is started in step SA9 and continues now (see reference numeral 302a). Thereby, the driver can surely obtain a sense of response of the downshift by the manual downshift or the shift point control based on the corner R or the road surface gradient and an increase in the actual deceleration 303. Following step SA22, step SA23 is performed.

[Step SA23]
In step SA23, the control circuit 130 determines whether or not the shift stage based on the manual shift in step SA11 or the shift point control based on the corner R or the road surface gradient is lower than the current shift stage (the shift stage shifted in step SA8). Is determined. As a result of the determination, if the gear determined in step SA11 is lower than the current gear, the process proceeds to step SA24, and if not, the process proceeds to step SA12. That is, as a result of the determination in step SA23, if the shift speed determined in step SA11 is not lower than the current shift speed, there is no need to perform a new shift (after step SA24), the process proceeds to step SA12.

[Step SA24]
In step SA24, the control circuit 130 outputs a downshift command by manual shift in step SA11 or shift point control based on the corner R or road gradient. As a result, a shift based on the driver's intention (manual shift or shift point control based on the corner R or road gradient) is prioritized over the shift based on the follow-up control, and a deceleration based on the driver's intention is realized. Following step SA24, step SA25 is performed.

  In the example of FIG. 11, the gear position shifted by the follow-up control (the gear position shifted at step SA8) and the gear position by the shift point control based on manual shift or corner R or road surface gradient in step SA11 are as follows: Shows the same case. That is, FIG. 11 shows a case where the speed determined in step SA11 is not lower than the current speed (step SA23-N) as a result of the determination in step SA23, and manual shift or corner in step SA11 is shown. No new downshift command is output after time T1 when the shift point control is determined based on R or road surface gradient (see reference numeral 304).

  In the case of FIG. 11, when the manual shift determination in step SA11 or the shift point control execution determination based on the corner R or the road surface gradient is made, the gradient of the target deceleration 403a is changed to a large value (step SA22). However, after the actual deceleration 303 is swept down along the target deceleration 403a of the gradient (after the time point T2), the driver does not feel the response (follow-up). The deceleration exceeding the maximum target deceleration Gt of control does not occur). This is the same as the conventional operation when a manual downshift is performed during the shift point control based on the normal corner R or road gradient, and there is no particular problem.

[Step SA25]
In step SA25, the control circuit 130 causes the maximum value of the deceleration (hereinafter referred to as the maximum target deceleration Gta) obtained by the manual shift in step SA11 or the shift point control based on the corner R or the road surface gradient to be the follow-up obtained in step SA4. It is determined whether or not it is larger than the maximum target deceleration Gt by the control.

  Here, the maximum target deceleration Gta by the manual shift in step SA11 or the shift point control based on the corner R or road gradient is different from the maximum target deceleration Gt obtained in step SA4 (follow-up control), and is obtained by the following method. It is done.

  The maximum target deceleration Gta is obtained by the control circuit 130 and is included in the “target deceleration” (step SA4) set as a joint target for the brake device 200 and the automatic transmission 10 described above. Here, the maximum target deceleration Gta is determined to be the same (or near) as the maximum deceleration (described later) determined from the type of shift and the vehicle speed.

  In FIG. 12, a broken line indicated by reference numeral 402a indicates a deceleration corresponding to the negative torque (braking force, engine brake) of the output shaft 120c of the automatic transmission 10 by manual shift in step SA11 or shift point control based on the corner R or road gradient. It shows acceleration and is determined by the type of shift and the vehicle speed.

  The maximum target deceleration Gta is determined so as to be substantially the same as the maximum value (the above-mentioned maximum deceleration) 402amax of the deceleration 402a acting on the vehicle by the shift of the automatic transmission 10. The maximum value 402amax of the deceleration 402a due to the shift of the automatic transmission 10 is determined with reference to the maximum deceleration map stored in the ROM 133 in advance. In the maximum deceleration map, the value of the maximum deceleration 402amax is determined as a value based on the type of shift and the vehicle speed.

  As a result of the determination in step SA25, if the maximum target deceleration by the shift point control based on manual shift or corner R or road surface gradient in step SA11 is larger than the maximum target deceleration Gt by the follow-up control obtained in step SA4, The process proceeds to step SA26, and if not, the process returns to step SA12.

[Step SA26]
In step SA26, the control circuit 130 changes the maximum target deceleration Gt by the follow-up control obtained in step SA4 to the maximum target deceleration Gta by the manual shift in step SA11 or the shift point control based on the corner R or the road surface gradient. . As a result, a shift based on the driver's intention (manual shift or shift point control based on the corner R or road gradient) is prioritized over the shift based on the follow-up control, and a deceleration based on the driver's intention is realized. Following step SA26, step SA27 is performed.

  It should be noted that instead of steps SA25 and SA26 or together with steps SA25 and SA26, when manual shift to a gear stage where a deceleration greater than or equal to the target deceleration 403a occurs or shift point control based on corner R or road gradient is performed. The target deceleration 403a can be changed, and the gradient can also be changed.

[Step SA27]
In step SA27, the gradient of the target deceleration 403a is set again by the control circuit 130 (the reset gradient is indicated by symbol αa in FIG. 12, and the target deceleration is indicated by symbol 403f). In step SA22, the gradient of the target deceleration 403a is changed to a large value, but in step SA26, the maximum target deceleration by shift point control based on manual shift or corner R or road gradient is changed from the maximum target deceleration Gt by tracking control. Along with the change to the speed Gta, the gradient αa of the target deceleration 403f is reset.

  In determining the gradient αa, first, after a manual shift in step SA11 or a downshift command by shift point control based on the corner R or the road surface gradient is output (step SA24, it is output at the time t1 in FIG. 12). Based on the time tb until the gear shift is actually (substantially) started (t3), the deceleration actually acting on the vehicle by the gear shift start time t3 (hereinafter referred to as the actual vehicle deceleration) is The initial minimum gradient value of the target deceleration 403a is determined so as to reach the maximum target deceleration Gta. In the above, the time tb from the time point t1 when the downshift command is output to the time point t3 at which the actual shift is started is determined based on the type of shift.

  In FIG. 12, a two-dot chain line indicated by reference numeral 404 corresponds to the initial gradient value of the initial target deceleration. In addition, the gradient that can be set as the target deceleration 403f in advance can be dealt with when an unstable phenomenon occurs in the vehicle (avoidance of the unstable phenomenon) so that a shock caused by deceleration does not increase. As described above, the gradient upper limit value and the lower limit value are set. A two-dot chain line indicated by reference numeral 405 in FIG. 12 corresponds to the above gradient upper limit value.

  The instability phenomenon of the vehicle is for some reason including a change in the friction coefficient μ of the road surface or a steering operation when deceleration acceleration (by brake control and / or engine brake by shifting) is applied to the vehicle. This means that the vehicle is in an unstable state, for example, the grip degree of the tire decreases, slips, or the behavior becomes unstable.

  In step SA27, the gradient αa of the target deceleration 403f is set to be larger than the gradient minimum value 404 and smaller than the gradient upper limit value 405, as shown in FIG.

  The initial gradient αa of the target deceleration 403f has the significance of setting an optimal deceleration change mode in order to smooth the initial deceleration change of the vehicle and to avoid an unstable vehicle phenomenon. The gradient α can be determined based on the accelerator return speed, the friction coefficient μ of the road surface, and the like. Further, the gradient αa can be changed between a manual shift and a shift by shift point control based on the corner R or the road surface gradient. These will be specifically described below with reference to FIG.

  FIG. 13 shows an example of a method for setting the gradient αa. As shown in FIG. 13, the gradient αa is set to be smaller as the road surface μ is smaller, and the gradient αa is set to be larger as the accelerator return speed is larger. Further, in the case of shift by shift point control based on the corner R or the road surface gradient, the gradient αa is set to be smaller than in the case of manual shift. This is because the shift by the shift point control is not a shift that is based directly on the driver's intention, so that the rate of deceleration is set moderately (relative deceleration acceleration is relatively small). In FIG. 13, the relationship between the gradient αa, the road surface μ, the accelerator return speed, and the like is a linear relationship, but can be set to be a nonlinear relationship. After step SA27, the process returns to step SA12.

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

  In this embodiment, when a shift point control based on a manual shift or a corner R or a road surface gradient is determined during the follow-up control, the shift based on the driver's intention is prioritized over the shift by the follow-up control. The That is, deceleration based on the driver's intention is realized while minimizing the driver's feeling of discomfort. The response of deceleration transmitted to the driver is not uncomfortable for the driver, and does not deteriorate the deceleration performance.

  Further, as shown in FIG. 1, even if the execution condition of the follow-up control is satisfied during the execution of the shift control based on the manual shift or the corner R or the road surface gradient, the manual shift or the corner R or the road surface is satisfied. Prioritizing the shift point control based on the gradient, the follow-up control is not performed until the manual shift or the shift point control based on the corner R or the road surface gradient is completed. As a result, the driver can perform the deceleration suitable for his / her intention without the driver feeling almost uncomfortable.

  In the deceleration control, there are advantages and disadvantages in the shift control for shifting the shift speed to the low speed stage and the brake control for operating the braking device, respectively. The shift control has the advantage that the steady engine braking force increases, but has the disadvantage that the responsiveness and controllability are not good. Brake control has the advantage of good responsiveness and controllability, but cannot be braked for a long time from the viewpoint of durability and reliability.

  In this regard, Patent Document 1 discloses a technique for operating a brake at the time of a manual downshift, but examination of the control content of the brake is insufficient. In particular, Patent Document 1 describes deceleration control (follow-up control) that performs downshifting of the automatic transmission and operation of the braking device so that the distance between the host vehicle and the preceding vehicle does not become a predetermined value or less. It has not been.

  The technique of the above-mentioned patent document 2 performs the downshift and the brake control at the same time only in an emergency because the drivability deteriorates when the downshift and the brake control are performed simultaneously. The technique of the above-mentioned patent document 3 is to release the deceleration control by downshift when the brake control is started.

  Neither of the techniques of Patent Documents 2 and 3 described above does not actively perform downshift and brake control at the same time. Advantages of simultaneously performing downshift and brake control (responsiveness of brake control, good controllability, downshifting, etc.) The steady increase in engine braking force is not being utilized. In order to take advantage of both the speed change control and the brake control, it is desired that effective speed reduction control is performed by simultaneously executing the speed change control and the brake control in the follow-up control.

  With regard to this point, in the present embodiment, the deceleration required for the inter-vehicle distance control is set as the overall target deceleration of the cooperative control, and the brake having good responsiveness is achieved in order to achieve the set target deceleration. Therefore, the current deceleration can be satisfactorily followed so that the current deceleration becomes the overall target deceleration of the cooperative control (deceleration necessary for inter-vehicle distance control). Thereby, the follow-up control (inter-vehicle distance control) for the inter-vehicle distance that changes every moment can be smoothly performed.

  In the present embodiment, the gear position target deceleration Gs is set to be between the current gear position deceleration Gf and the maximum target deceleration Gt (step SA6). That is, the deceleration due to the engine braking force obtained by downshifting (shift control) to the shift stage to be selected is the engine brake force (current shift stage deceleration Gf) of the shift stage before starting the deceleration control and the maximum target deceleration. It is set to be between Gt (step SA7). As a result, even when the deceleration control is performed in which the brake control and the shift control are performed simultaneously in cooperation (steps SA8 and SA9), the deceleration is not excessive and the driver does not feel uncomfortable. Moreover, even after the inter-vehicle distance and relative vehicle speed reach the target values and the brake control is finished (step SA15), the engine brake by the downshift continues to be effective, so the vehicle speed associated with the end of the brake control (step SA15) Brake control hunting due to an increase (especially in the case of a downhill) can also be effectively suppressed.

  In the present embodiment, the current deceleration 303 is calculated in real time at the time T3 to T6 in FIG. 11 after the current deceleration 303 matches the maximum target deceleration Gt (step SA12). As shown in steps SA14 and SA15, the target deceleration 403 (here, the same as the current deceleration 303) coincides with the gear stage target deceleration Gs (Ge). When it decreases to the brake control, the brake control ends. That is, the brake control ends when the target deceleration 403 calculated in real time matches the gear position target deceleration Gs (Ge) (deceleration after downshift control). That is, the brake control is not continued until the target deceleration 403 (here, the current deceleration 303) returns to the deceleration at the time (T0) when the deceleration control is started (current gear stage deceleration Gf). Absent.

  If the deceleration control is performed only by the brake control without performing the shift control, the target deceleration 403 returns to the vicinity of the current shift speed deceleration Gf, and the target inter-vehicle distance and the relative vehicle speed can be determined only by the current shift speed deceleration Gf. It is necessary to continue the brake control until it is realized. On the other hand, in the present embodiment, since the shift control and the brake control are simultaneously performed in cooperation, the target deceleration 403 is approximately equal to the deceleration (shift stage target deceleration Gs (Ge)) obtained by the shift control. The brake control can be terminated when the target inter-vehicle distance and the relative vehicle speed are realized only by the deceleration obtained by the shift control. Thereby, in this embodiment, brake control can be completed in a shorter time. This ensures the durability of the brake (prevents brake fade, pads, and disc wear).

  In the present embodiment, the brake control is terminated when the target deceleration 403 (here, the current deceleration 303) matches the gear position target deceleration Gs (Ge) (deceleration after downshift control). From that point on, deceleration control with only shift control is performed. As a result, since the deceleration 303 after the shift control and the deceleration after the shift control (deceleration due to the engine braking force) substantially coincide with each other, the deceleration control is performed only by the shift control. can do.

  As described above, the brake control is terminated when the target deceleration 403 substantially coincides with the shift speed target deceleration Gs (Ge) (deceleration due to the engine braking force after the shift control). On the other hand, the shift control is performed after a predetermined time elapses after the accelerator is turned on after the brake control ends (step SA15) (steps SA16 to SA18) or when the inter-vehicle distance exceeds a predetermined value after the brake control ends (step SA20). finish. As described above, by dividing the termination (return) conditions of the brake control and the shift control, the brake control can be completed in a short time, which leads to ensuring the durability of the brake. Further, since the shift control is not completed unless the inter-vehicle distance exceeds a predetermined value, the engine brake continues to be effective.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. 14 and 15. Note that a description of parts common to the first embodiment is omitted.

FIG. 14 is a flowchart corresponding to FIG. 5-2 of the first embodiment. In the second embodiment, the operation of the portion corresponding to FIGS. 5-1 and 5-3 of the first embodiment is applied as it is, and the operation corresponding to FIG. 5-2 is replaced with the contents shown in FIG.
FIG. 15 is a time chart showing the operation of the second embodiment.

The operation of the second embodiment will be described with reference to FIG.
Steps SB11 to SB14 are the same as steps SA11 to 14 in FIG. 5-2 of the first embodiment, and steps SB15 and SB16 are the same as steps SA23 and SA24 in FIG. The description is omitted.

[Step SB17] and [Step SB18]
As shown in FIG. 14, the step SB17 outputs a signal indicating the necessity of downshifting from the manual shift determination unit 95, or the corner measurement / estimation unit 119 or the road gradient measurement / estimation at the time T1 in FIG. If it is determined that a signal indicating the need for downshifting based on the measurement / estimation result from the unit 118 has been generated (step SB11-Y), the signal is always executed (regardless of whether step SB15 is successful).

  In step SB17, the control circuit 130 interrupts the brake feedback control. That is, if the brake control started at step SA9 and continuing at present is determined positively at step SB11, it is temporarily interrupted and the brake control amount is controlled to increase by a predetermined value ( Step SB18). If the determination in step SB11 is positive at time T1 in FIG. 15, feedback control is interrupted (step SB17), and the brake control amount 302 is controlled to increase by a predetermined value ΔFb (step SB18). , See reference numeral 302b in FIG. As a result, the actual deceleration 303 changes from the time point T1 to a larger value as indicated by reference numeral 403b.

  The amount by which the brake control amount 302 is increased (predetermined value ΔFb) can be determined according to the type of shift in the shift control in step SA8, for example. In the feedback control, the brake amount is controlled in the order of target change → deviation generation → hydraulic pressure correction, so there is a possibility that the response time becomes longer. Therefore, if the determination in step SB11 is positive, the feedback control is interrupted and the brake control amount 302 is increased by a predetermined value ΔFb, thereby improving the responsiveness. As a result, the driver can surely and quickly obtain a sense of response to a downshift by manual downshift or a shift point control based on the corner R or road gradient and an increase in the actual deceleration 303.

  In step SB18, when the brake control amount 302 is increased by a predetermined value ΔFb, the brake control amount 302 can be increased at a predetermined gradient in order to prevent a transient shock. In the example of FIG. 15, the brake control amount 302 is controlled to increase by a predetermined value ΔFb at a predetermined gradient during a predetermined time (time from T1 to T2). Following step SB18, step SB19 is performed.

[Step SB19]
In step SB19, the control circuit 130 determines whether or not the change in the actual deceleration of the vehicle has ended. The determination can be made based on whether or not the detected value of the actual deceleration 303 detected by the acceleration sensor 90 has converged to a constant value after the brake hydraulic pressure is increased in step SB18. In this case, when the difference between the previous sampling value and the current value is equal to or smaller than the predetermined value continues for a predetermined number of times, it can be determined that the condition of step SB19 is satisfied. Alternatively, if the time required for the actual deceleration 303 to converge to a certain value after the brake hydraulic pressure is increased is obtained, and the passage of the time is detected by a timer, the condition of step SB19 is established. It is possible to determine. In the example of FIG. 15, it is assumed that the condition of step SB19 is satisfied at time T2. Following step SB19, step SB20 is performed.

[Step SB20]
In step SB20, the target deceleration 403 is recalculated by the control circuit 130. Since the actual deceleration 303 is expected to change due to the increase in the brake control amount 302 in step SB18 (see reference numeral 403b), the target deceleration 403 starts from the time point (T2) when the condition in step SB19 is satisfied. Is reset (step SB20). The resetting method is the same as the setting method of the target deceleration 403 in step SA5. The reset target deceleration 403 is indicated by reference numeral 403c. The actual deceleration 303 at the time point (T2) when the condition of step SB19 is satisfied is indicated by a symbol Gk. Following step SB20, step SB21 is performed.

[Step SB21]
In step SB21, the control circuit 130 resumes brake feedback control. The feedback control at this time is performed based on the reset target deceleration 403c. In FIG. 15, the brake feedback control is resumed from the time T2. The brake control amount 302 after the restart is indicated by reference numeral 302c. Following step SB21, step SB12 is performed.

  According to the second embodiment described above, when manual shift or shift point control based on the corner R or road gradient is determined by the driver's intention, the actual deceleration 303 has high responsiveness. It is possible to give the driver a sense of increased response. The feeling of response does not give the driver a sense of incongruity and does not deteriorate the deceleration performance. When the brake feedback control is resumed after raising the brake control amount 302 by the predetermined amount ΔFb, the target deceleration 403c is reset from the change point Gk of the actual deceleration 303 due to the increase in ΔFb. Characteristics are obtained.

  In the above embodiment, an example using brake control has been described, but regenerative control using an MG device (such as a hybrid system) provided in a power train system can be used instead of the brake. In the above description, the stepped automatic transmission 10 is used as the transmission. However, the transmission can be applied to the CVT as well as the automatic transmission mounted on the hybrid vehicle. . In the above description, the deceleration acceleration (G) is used as the deceleration indicating the amount by which the vehicle is decelerated, but it is also possible to control based on the deceleration torque.

It is a flowchart which shows the control content of the basic control flow of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a schematic block diagram of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. 1 is a skeleton diagram showing an automatic transmission according to a first embodiment of a vehicle deceleration control device of the present invention. It is a figure which shows the action | operation table | surface of the automatic transmission in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows a part of control content of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows a part of other control content of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows another part of the control content of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the target deceleration map in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the gear stage target deceleration map in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the deceleration which arises according to the output shaft rotation speed and gear stage in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the relationship between the gear stage target deceleration, the present gear stage deceleration, and the maximum target deceleration in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the deceleration for every vehicle speed of each gear stage in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a time chart which shows operation | movement of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is explanatory drawing for demonstrating the gradient of the target deceleration of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is explanatory drawing for demonstrating how to determine the gradient of the target deceleration of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart which shows a part of control content of 2nd Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a time chart which shows operation | movement of 2nd Embodiment of the deceleration control apparatus of the vehicle of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automatic transmission 40 Engine 90 Acceleration sensor 95 Manual shift judgment part 97 Relative speed detection / estimation part 101 Inter-vehicle distance measurement part 114 Throttle opening sensor 116 Engine speed sensor 117 Pattern selection switch 118 Road gradient measurement / estimation part 119 Corner measurement Estimator 120c Output shaft 121a-121c Solenoid valve 122 Vehicle speed sensor 123 Shift position sensor 130 Control circuit 131 CPU
133 ROM
138a to 138c Solenoid valve drive unit 200 Brake device 220 Hydraulic control circuit 230 Brake control circuit 301 Accelerator opening 302 Brake control amount 302a Brake control amount 302b Brake control amount 302c Brake control amount 303 Actual deceleration 304 Shift output 402 Automatic transmission Deceleration by shifting 403 Target deceleration 403a Target deceleration 404 Target gradient minimum value 405 Gradient upper limit value 408 Clutch torque L1 Brake braking force signal line Gt Maximum target deceleration by tracking control Gta Manual shift or corner R or road surface gradient SG1 Brake braking force signal SG2 Brake control signal α Gradient ΔFb Brake control amount

Claims (7)

A vehicle deceleration control device that performs deceleration control by an operation of a braking device that generates a braking force on a vehicle and a shift operation that shifts the transmission of the vehicle to a relatively low speed gear ratio or gear ratio,
When the first deceleration control registered in advance as a deceleration having a relatively large relationship with the driver's intention is being performed, it is registered in advance as a deceleration having a relatively small relationship with the driver's intention. When the condition for performing the second deceleration control is performed, the first deceleration control is performed without performing the second deceleration control. A vehicle deceleration control device. A vehicle deceleration control device that performs deceleration control by an operation of a braking device that generates a braking force on a vehicle and a shift operation that shifts the transmission of the vehicle to a relatively low speed gear ratio or gear ratio,
When the second deceleration control previously registered as a deceleration having a relatively small relationship with the driver's intention is being performed, it is registered in advance as a deceleration having a relatively large relationship with the driver's intention. The vehicle is controlled so that the braking characteristic is changed from the braking force generated by the second deceleration control when the condition for performing the first deceleration control is established. Deceleration control device. The vehicle deceleration control device according to claim 1 or 2,
The first deceleration control is the deceleration control based on a vehicle traveling environment including at least one of a road gradient and a road shape on which the vehicle travels, or the deceleration control with manual shift.
The vehicle deceleration control device, wherein the second deceleration control is the deceleration control based on a distance between the vehicle and an obstacle including a preceding vehicle ahead of the vehicle. The vehicle deceleration control device according to claim 2,
The change of the braking characteristic is to change the rate of change over time of the target deceleration of the second deceleration control. The vehicle deceleration control device according to claim 2,
The change of the braking characteristic is performed by changing the braking force generated by the deceleration control after the change to the target deceleration of the second deceleration control without performing feedback control with respect to the target deceleration of the second deceleration control. A deceleration control device for a vehicle, characterized in that the value is changed to a value larger than a corresponding braking force. The vehicle deceleration control device according to any one of claims 2 to 5,
When the maximum value of the target deceleration by the first deceleration control is larger than the maximum value of the target deceleration by the second deceleration control, the maximum value of the target deceleration of the second deceleration control is greater than the maximum value of the target deceleration by the second deceleration control. The vehicle deceleration control device, wherein the maximum value of the target deceleration by the deceleration control after the change is increased. The vehicle deceleration control device according to any one of claims 1 to 6,
The vehicle deceleration control device, wherein the braking device is at least one of a means for stopping rotation of a wheel of the vehicle and a means for generating electric power using the rotational force of the wheel.

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