JP2005147292A - Shift control device for transmission and shift control method of transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly return to operation intended by an operator when speed reduction is unnecessary. <P>SOLUTION: A travel state determining part 22 determines the state of opening of an accelerator. A parameter calculating part 23 obtains a vehicle reaching time required by a one's own vehicle to reach a precedent vehicle based on the distance between the precedent vehicle and the own vehicle mounted with a transmission to be controlled. A comparing part 24 compares the vehicle reaching time with a predetermined threshold value. On the condition that the opening of the accelerator determined by the travel state determining part 22 is full and the vehicle reaching time is equal to or smaller than the predetermined threshold value, a speed change instructing part 25 changes the gear ratio of the transmission to be lower than the current gear ratio. Thereafter, when the distance between the own vehicle and the precedent vehicle is equal to or larger than the predetermined value, the speed change instructing part 25 changes the gear ratio of the transmission to a gear ratio adapted to the travel state of the own vehicle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to control of an automatic transmission. More specifically, the present invention relates to a transmission control device for a transmission and a transmission control for the transmission that can quickly return to the operation intended by the driver when deceleration is no longer necessary. It is about the method.

  In automatic transmission (hereinafter abbreviated as AT) control, shift control is known in which a driver's intention to decelerate is detected when the accelerator is turned off, and the vehicle decelerates by downshifting. With regard to such shift control, for example, in Patent Document 1, the necessity of deceleration is determined based on the inter-vehicle distance and relative speed, and the inter-vehicle distance from the preceding vehicle does not change when deceleration is necessary. Discloses a technique for decelerating by downshifting.

JP 2003-54395 A

  However, when decelerating by downshifting, the technology disclosed in Patent Document 1 mentions at which timing to return to the normal shift mode when deceleration is no longer necessary after downshifting. Not. For this reason, after there is no need for deceleration, it is not possible to quickly return to driving according to the driver's intention, and drivability may be reduced.

  Accordingly, the present invention has been made in view of the above, and is a transmission that can quickly return to the driving intended by the driver when deceleration is no longer necessary while securing a distance between the preceding vehicle and the vehicle. An object of the present invention is to provide a transmission control device and a transmission control method for a transmission.

  In order to achieve the above-mentioned object, a transmission control device for a transmission according to the present invention controls a shift schedule of a transmission mounted on a vehicle and determines at least a travel state of an accelerator. A parameter calculation unit for obtaining a vehicle approach parameter for determining an approach between the preceding vehicle and the host vehicle based on a relative distance between the unit, the preceding vehicle, and the host vehicle on which the transmission to be controlled is mounted. Comparing the vehicle approach parameter obtained by the parameter calculation unit with a predetermined threshold value to determine whether or not the host vehicle is approaching the preceding vehicle and starting control, and the accelerator When the opening degree of the vehicle is fully closed and the vehicle approach parameter is less than or equal to the predetermined threshold value, the transmission gear ratio is changed to a lower speed gear ratio than the current state, and the relative When away is above a predetermined value, characterized by having a a shift command unit that allows to change the speed ratio of the transmission to the combined gear ratio to the running state of the vehicle.

  In the transmission control device for the transmission, when the vehicle approach parameter for determining the approach between the preceding vehicle and the host vehicle is smaller than a predetermined threshold, the transmission is changed to a gear ratio lower than the current state. Thereby, since the own vehicle can be decelerated, the inter-vehicle distance from the preceding vehicle can be ensured. Further, when the inter-vehicle distance between the preceding vehicle and the host vehicle is greater than or equal to a predetermined value, the transmission gear ratio is allowed to be changed to a gear ratio that matches the traveling state of the host vehicle. When a sufficient inter-vehicle distance is ensured in the meantime, it is possible to quickly return to a state where driving according to the driver's intention can be performed. This improves drivability.

  Further, the transmission control device for a transmission according to the present invention is the transmission control device for the transmission, wherein a value obtained by dividing the inter-vehicle distance between the preceding vehicle and the host vehicle by the host vehicle speed, or the inter-vehicle distance. A value obtained by dividing by a relative speed between the preceding vehicle and the host vehicle is used as the vehicle approach parameter.

  Thus, if the value obtained by dividing the inter-vehicle distance by the own vehicle speed or the value obtained by dividing the inter-vehicle distance by the relative speed between the preceding vehicle and the own vehicle is used as the vehicle approach parameter, As long as there is a certain speed difference, the downshift can be appropriately performed to ensure a sufficient inter-vehicle distance. Further, when a value obtained by dividing the inter-vehicle distance by the own vehicle speed is used as the vehicle approach parameter, the inter-vehicle time becomes finite as long as the own vehicle is traveling. For this reason, even when the relative speed between the host vehicle and the preceding vehicle is close to zero, it is possible to appropriately perform the downshift and to ensure a sufficient inter-vehicle distance.

  Further, in the transmission control device for a transmission according to the next aspect of the invention, in the transmission control device for the transmission, even when the inter-vehicle distance is smaller than the predetermined value, the accelerator has an opening larger than that in the fully closed state. When the driving state determination unit determines, the shift command unit permits the change of the transmission gear ratio to the transmission gear ratio that matches the driving state of the host vehicle.

  As described above, when the accelerator opening is larger than a certain level, the driver's intention to accelerate is recognized, so permission to change the transmission gear ratio to the gear ratio in accordance with the traveling state of the host vehicle is given. In this way, since the host vehicle can be driven according to the driver's intention, drivability is improved.

  In the transmission control device for a transmission according to the present invention, when the vehicle has a corner in the traveling direction of the preceding vehicle in the transmission control device for the transmission, the shift command unit is set based on the low speed gear ratio. Is further characterized in that the transmission gear ratio is changed to a lower gear ratio.

  The fact that there is a corner in front of the preceding vehicle means that there is a high possibility that the preceding vehicle will decelerate in front of the corner and the inter-vehicle distance will rapidly decrease. For this reason, there is a high possibility that a stronger engine brake is required than in the case where there is no corner. By adopting the above configuration, a sufficient inter-vehicle distance can be ensured by a stronger engine brake.

  Further, the transmission shift control method according to the present invention includes a step of determining at least an accelerator opening state, a preceding vehicle, and a control target when controlling a shift schedule of a transmission mounted on a vehicle. A step of obtaining a vehicle approach parameter for determining an approach between the preceding vehicle and the host vehicle based on a relative distance from the host vehicle equipped with a transmission, and comparing the vehicle approach parameter with a predetermined threshold value By determining whether the host vehicle is approaching the preceding vehicle, the control is started, the accelerator opening is fully closed, and the vehicle approach parameter is equal to or less than the predetermined threshold. In this case, the step of changing the transmission to a speed ratio lower than the current speed ratio, and if the relative distance is greater than or equal to a predetermined value, the change to the speed ratio that matches the vehicle running state is permitted. Process and Characterized in that it comprises a.

  In the transmission control device of this transmission, when the vehicle approach parameter is smaller than a predetermined threshold, the transmission is changed to a transmission ratio lower than the current state. Thereby, since the own vehicle can be decelerated, the inter-vehicle distance from the preceding vehicle can be ensured. Further, when the inter-vehicle distance between the preceding vehicle and the host vehicle is equal to or greater than a predetermined value, it is permitted to change the gear ratio of the transmission to a gear ratio that matches the traveling state of the host vehicle. As a result, when a sufficient inter-vehicle distance is ensured with the preceding vehicle, it is possible to quickly return to a state in which driving can be performed according to the driver's intention, and drivability is improved.

  According to the speed change control device and the speed change control method for a speed change device according to the present invention, when the speed reduction is not necessary while ensuring the inter-vehicle distance from the preceding vehicle, the drive is promptly performed by the driver. Can return

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements of the examples in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  The transmission control device and the transmission control method for a transmission control a transmission schedule of the transmission, and prepare a downshift control based on the relative distance between the preceding vehicle and the host vehicle, and based on the relative distance. Based on the vehicle approach parameter obtained in this way, it is characterized in that it is permitted to change to a gear ratio that matches the traveling state of the host vehicle. Next, a transmission control device and a transmission control method for a transmission according to an embodiment of the present invention will be described. In the following description, a torque converter type multi-stage AT is taken as an example, but the scope of application of the present invention is not limited to this, and a non-stage AT such as a belt-type continuously variable transmission (CVT) or MMT (Manual Mode) The transmission can be applied to all other transmission controls that can execute shift control in accordance with vehicle running conditions. Here, the vehicle running state is expressed by using at least the vehicle speed and the accelerator opening as parameters.

  FIG. 1 is an explanatory diagram showing a transmission control device for a transmission according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a transmission control method for a transmission according to an embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating a vehicle including a transmission control device for a transmission according to an embodiment of the present invention and a preceding vehicle. As shown in FIG. 1, the transmission control device 20 includes a map storage unit 21, a traveling state determination unit 22, a parameter calculation unit 23, a comparison unit 24, and a shift command unit 25. The Here, the parameter calculation unit 23, the comparison unit 24, and the shift command unit 25 serve as a part for executing the transmission control method according to the present invention, and are referred to as a processing unit 20p.

  The map storage unit 21, the parameter calculation unit 23, the comparison unit 24, and the shift command unit 25 are connected via an interface port (I / P) 26 of the transmission control device 20. As a result, the map storage unit 21, the parameter calculation unit 23, the comparison unit 24, and the shift command unit 25 can exchange data in both directions. Note that data may be transmitted or acquired in one direction as necessary.

  Further, the transmission control device 20 and the engine ECU 30 are connected to each other via an input / output port (I / P) 26 of the transmission control device 20, and exchange data with each other. be able to. Thus, the transmission control device 20 can acquire engine control data of the engine ECU 30 and can realize emphasis control between the transmission control device 20 and the engine ECU 30. Further, a G sensor 34 and a steering angle sensor 36 are connected to the input / output port (I / P) 26, and the transmission control device 20 can acquire the lateral G value and the steering angle value from these. Here, the AT 10 can realize speed change control in accordance with the vehicle running state.

  The map storage unit 21 stores a computer program including processing procedures of the transmission control method according to the present invention. Here, the map storage unit 21 can be configured by a non-volatile memory such as a flash memory, a volatile memory such as a RAM (Random Access Memory), or a combination thereof. The processing unit 20p is configured by a memory and a CPU.

  The computer program may be capable of realizing the processing procedure of the transmission control method according to the present invention in combination with the computer program already recorded in the processing unit 20p or the engine ECU 30. The processing unit 20p may realize the functions of the parameter calculation unit 23, the comparison unit 24, and the shift command unit 25 using dedicated hardware instead of the computer program.

  Next, the processing procedure of the transmission control apparatus and control method according to the present invention will be described. Here, since there is a corner in front of the preceding vehicle, the case where the preceding vehicle decelerates and the relative distance between the host vehicle and the preceding vehicle becomes small will be described as an example. In addition to the above case, the present invention is generally applicable when the relative distance between the host vehicle and the preceding vehicle is reduced. Further, the inter-vehicle time is used as the vehicle approach parameter for determining the approach between the preceding vehicle 41 and the host vehicle 40, and the inter-vehicle distance is used as the relative distance between the preceding vehicle 41 and the host vehicle 40. However, what can be applied to is not limited to these.

  First, whether the traveling state determination unit 22 of the transmission control device 20 is cornering the preceding vehicle 41 or the vehicle 40 (hereinafter referred to as the host vehicle) provided with the transmission control device of the transmission according to the embodiment of the present invention. It is determined whether or not (step S101, FIG. 2). The host vehicle 40 is determined based on, for example, the lateral G value of the G sensor 34 and the steering angle value of the steering angle sensor 36 provided in VSC (Vehicle Stability Control). In the present embodiment, the lateral G value and the steering angle value are taken into the traveling state determination unit 22.

As for the preceding vehicle 41, the preceding vehicle 41 is cornering from the position information of the own vehicle 40 acquired from the GPS (Global Positioning System) satellites 43 ₁ , 43 ₂ , the inter-vehicle distance information, and the front road information by navigation. Judge whether there is. Here, the inter-vehicle distance L between the host vehicle 40 and the preceding vehicle 41 can be obtained by, for example, the optical inter-vehicle distance sensor 42 provided in the host vehicle 40.

  If at least one of the own vehicle 40 or the preceding vehicle 41 is cornering (step S101; Yes), the accurate inter-vehicle distance L between the two cannot be determined, so the process returns to the start and continues monitoring. If the host vehicle 40 and the preceding vehicle 41 are cornering (step S101; No), it is determined whether or not the flag F is 0 (step S102). Since the flag F at the start of control is 0 (step S102; Yes), the traveling state determination unit 22 next determines whether or not the accelerator opening state is fully closed (step S103). Step S103; No) Monitoring is resumed after returning to the start. This flag F is set to 0 when permission to return a shift stage, which will be described later, is given, indicating that a series of processes in the transmission control method for a transmission according to the present invention has been completed.

  When the accelerator opening is fully closed (step S103; Yes), the comparison unit 24 sets an inter-vehicle time Ti, which is an example of a vehicle approach parameter based on a relative distance between the preceding vehicle 41 and the host vehicle 40, and a predetermined threshold t1. Compare Then, it is determined whether the inter-vehicle time Ti is equal to or less than a predetermined threshold value t1 (step S104). This is because when the host vehicle 40 travels following the preceding vehicle 41, the timing at which the driver of the host vehicle 40 performs a deceleration operation such as a foot brake or a manual shift collides with the vehicle distance L. It depends more strongly on the time until. For this reason, the inter-vehicle time Ti is more preferable as the vehicle approach parameter. Therefore, if the inter-vehicle time Ti that is an index of the time until the collision is used, the driver's intention can be reflected in the deceleration by the shift control, so the driver is less likely to feel discomfort in the shift control, and drivability Will improve.

  Here, the inter-vehicle time Ti is a value (L / V1) obtained by dividing the inter-vehicle distance L between the host vehicle 40 and the preceding vehicle 41 by the host vehicle speed V1, and is a parameter calculation unit 23 of the transmission control device 20. Is calculated from the inter-vehicle distance L acquired from the optical inter-vehicle distance sensor 42 and the engine ECU 30, and the host vehicle speed V1. In addition, instead of the inter-vehicle time Ti, the collision time Tc (the inter-vehicle distance L / the relative vehicle speed Vr (= the own vehicle speed V1−the preceding vehicle speed V2)), the arrival time of the own vehicle 40, and the preceding vehicle 40 are preceded as vehicle approach parameters. The relative vehicle speed Vr obtained from the relative distance to the vehicle 41 or the inter-vehicle distance L and other parameters can be used.

  The determination as to whether or not the inter-vehicle time Ti is equal to or less than the predetermined threshold value t1 is made from, for example, the threshold maps shown in FIGS. 4-1 and 4-2. Here, FIGS. 4A and 4B are conceptual diagrams of a threshold map of the inter-vehicle time with respect to the own vehicle speed and the relative vehicle speed. This threshold map is stored in the map storage unit 21, and as shown in FIG. 4B, the threshold t1 can be determined based on the magnitudes of the host vehicle speed V1 and the relative vehicle speed Vr.

  In this threshold map, the threshold t1 is set to increase as the host vehicle speed V1 and the relative vehicle speed Vr increase. When the host vehicle speed V1 or the relative vehicle speed Vr increases, the time for the host vehicle 40 to approach the preceding vehicle 41 is shortened. For this reason, the engine brake is applied from an earlier stage by downshifting to the host vehicle 40 at an earlier stage. As shown in FIG. 4B, by mapping the threshold value t1 based on the relationship between the host vehicle speed V1 and the relative vehicle speed Vr, it is possible to obtain a collision-related index similar to the case where the collision time Tc is used. . The threshold map may use the host vehicle speed V1 and the relative vehicle speed Vr as parameters, or may determine the threshold t1 using the host vehicle speed V1 and the inter-vehicle distance L as parameters. The threshold value t1 may be determined using as a parameter. In this way, the threshold map can be set by selecting parameters of the threshold map so that the AT 10 can be controlled most preferably.

  The comparison unit 24 provided in the transmission control device 20 acquires the host vehicle speed V1 and the relative vehicle speed Vr acquired from the engine ECU 30 or the like. And the said threshold value map stored in the map storage part 21 is read, The said speed information is given to a threshold value map, and threshold value t1 is calculated | required. In step S104, the threshold value t1 is compared with the inter-vehicle time Ti. If the inter-vehicle time Ti is equal to or less than the threshold t1 (step S104; Yes), the transmission control device 20 performs a downshift (stepless speed change). The machine starts preparations (downshift control) for changing to a lower speed ratio. If the inter-vehicle time Ti is equal to or less than the threshold value t1, the vehicle will collide with the preceding vehicle 41 after t1. Therefore, in order to avoid such a situation, the engine brake is applied to the host vehicle 40 to decelerate. Since the accelerator opening is fully closed, it can be determined that the driver has an intention to decelerate, and thus the control does not contradict the driver's intention. At this time, the flag F is set to 1 (step S105), and it is determined whether or not there is a corner ahead of the preceding vehicle 41 (step S106).

  If there is no corner in front of the preceding vehicle 41 (step S106; No), the shift command unit 25 of the transmission control device 20 uses the N (for example, N = 1, N is an integer) stage downshift command. Is issued (step S107). Here, in the case of a continuously variable transmission, a command to change to a gear ratio lower than the current state is issued. Can be controlled (the same applies hereinafter).

  In response to this downshift command, the AT 10 shifts down to N steps (in a continuously variable transmission, shifts to a lower gear ratio than the current state), thereby changing to a gear ratio that matches the traveling state of the host vehicle. At this time, for example, a shift speed at which the relative vehicle speed Vr (= V1−V2) between the host vehicle speed V1 and the preceding vehicle speed V2 becomes 0 is selected, and the number N of downshifts so that the shift can be made to the shift speed. Alternatively, the gear ratio may be determined. Further, when the number of steps to be downshifted reaches a plurality of steps, it may be shifted to the target shift step at a stroke, or may be downshifted step by step. The latter case is more preferable because the shift shock can be reduced.

  When there is a corner in the traveling direction of the preceding vehicle 41 (step S106; No), the shift command unit 25 of the transmission control device 20 is down by N + α (where α = 1, α is an integer). A shift command is issued (step S107). In the case of a continuously variable transmission, a command to change to a lower gear ratio is issued than when there is no corner in the traveling direction of the preceding vehicle. In response to this downshift command, the AT 10 downshifts N + α stages. The fact that there is a corner in the traveling direction of the preceding vehicle 41 means that the preceding vehicle 41 decelerates in front of the corner and the inter-vehicle distance L is likely to be shortened rapidly. Therefore, the engine brake is stronger than when there is no corner. Because it is necessary. By controlling in this way, the speed of the host vehicle can be sufficiently reduced by a stronger engine brake. In this example, α is set to 1, and the level is shifted down by one step more than when no corner exists. However, the size of α may be changed depending on the curvature of the corner.

  In this embodiment, when there is a corner in front of the preceding vehicle 41, an N + α step downshift is performed. However, for example, when there is a downhill in front of the preceding vehicle 41, an N + α step downshift is performed as described above. May be. Further, when there is a traffic jam ahead of the preceding vehicle 41 from the VICS information, the N + α step may be similarly downshifted. Thus, when the deceleration of the preceding vehicle increases due to the situation ahead of the preceding vehicle 41, it is possible to apply a stronger engine brake by downshifting N + α steps.

  Here, the downshift method of AT10 will be described. FIG. 5 is a schematic diagram showing the structure of an AT according to an embodiment of the present invention. FIG. 6 is an explanatory diagram showing an engagement relationship of the clutch, the brake, etc. with respect to the shift position of the AT according to the embodiment of the present invention. The AT 10 is a multi-stage automatic transmission that uses the torque converter 3. The output from the engine is transmitted from the input shaft 2 to the torque converter 3. Then, after being input from the transmission unit input shaft 5 to the transmission unit 10t of the AT 10 through the electromagnetic clutch 4 and decelerated, the transmission shaft 6 transmits the differential gear to rotate the drive wheels.

  For example, while traveling at the fifth speed (shift position is 5th), the clutches C0, C1, C2 of the AT10 and the brake B0 are engaged to transmit power, and the brake B2 is engaged but not transmitted. is there. Here, the AT 10 is downshifted from the fifth speed to the fourth speed by a one-stage downshift command issued from the shift command section 25 of the control device 20. Then, the clutch C0 is engaged by the hydraulic pressure and the engagement of the brake B0 is released, and the gear is downshifted to the fourth speed. The one-way clutch F0 is engaged to transmit power.

  When the AT 10 is downshifted (steps S107 and S108), the traveling state determination unit 22 determines whether or not the inter-vehicle distance L with the preceding vehicle 41 is greater than a predetermined value (step S109). Immediately after the downshift, since the inter-vehicle distance L is not normally opened by a predetermined value or more (step S109; No), it is determined in the next step whether or not the accelerator is fully closed (step S110). When the accelerator is fully closed (step S110; Yes), in the order of steps S101, S102, and S109, the inter-vehicle distance L becomes a predetermined value or more, or the accelerator is stepped on (not fully closed). It is determined again whether there is any (step S110). During the re-determination of the inter-vehicle distance L and the accelerator opening, the shift command unit 25 has not issued a shift stage return permission command, so the flag F is maintained at 1. Thereby, step S103-step S108 are skipped.

  Here, during the re-determination of the inter-vehicle distance L and the accelerator opening, whether the predetermined inter-vehicle distance L can be ensured or whether the driver's intention to accelerate can be confirmed (the accelerator opening is not fully closed). Unless it is satisfied, permission to return the gear position is not instructed. In other words, the shift speed is maintained at the shift speed when the downshift is performed. For example, even if a manual shift is performed in an automatic transmission having a manual mode, such a shift is not accepted. As a result, gear shifting is not permitted except when a sufficient inter-vehicle distance L is ensured or when the driver's intention to accelerate is permitted, so driving that respects the driver's intention while ensuring a sufficient inter-vehicle distance. realizable.

  If it is determined in step S110 that the accelerator is fully closed, the process returns to step S101 and the determination of the inter-vehicle distance L or the accelerator opening is repeated. At this time, when at least one of the preceding vehicle 41 or the host vehicle 40 is cornering, the shift command unit 24 does not instruct permission to return to the shift stage. As a result, the gear position during cornering is maintained and deterioration of drivability is suppressed.

  If the inter-vehicle distance L is equal to or greater than a predetermined value (step S109; Yes), the shift command unit 25 returns the shift stage, that is, shifts to the shift stage according to the traveling state of the host vehicle 40 (in the case of a continuously variable transmission). Is permitted to change to the gear ratio in accordance with the traveling state of the host vehicle (step S112). As described above, if the return of the gear position is permitted by the inter-vehicle distance L, for example, when the preceding vehicle 41 is accelerated or the lane is changed and a sufficient inter-vehicle distance is secured, the vehicle responds to the driver's intention. You can quickly return to a state where you can drive. If the return of the gear position is permitted, the traveling state determination unit 22 sets the flag F to 0 (step S113). Thereafter, the above procedure is repeated and monitoring is continued. Here, the shift to the gear position in accordance with the traveling state of the host vehicle 40 includes not only a shift up but also a shift down when the driver wants to obtain a strong acceleration force.

  When the inter-vehicle distance L is not greater than or equal to the predetermined value (step S109; No), the traveling state determination unit 22 determines the accelerator opening state (step S110). If the accelerator is not fully closed (step S110; No), that is, if the accelerator opening is greater than or equal to a certain degree, the driver's intention to accelerate is recognized, so the shift command unit 25 gives permission to return to the shift stage. When the return of the gear position is controlled only by the inter-vehicle distance L, even if the driver shows an intention to accelerate regardless of the inter-vehicle distance L, this may not be reflected, and the driver may feel uncomfortable. However, with the above configuration, for example, the driver's intention to accelerate can be reflected in the shift control, so the driver can drive the vehicle 40 according to his / her intention, and drivability is improved. .

  At this time, as shown in FIG. 2, the traveling state determination unit 22 determines whether or not a predetermined time or more has elapsed with the accelerator not fully closed (step S111). In step S111; Yes), it is preferable to perform control so that the shift command section 25 gives permission to return the shift stage. By controlling in this way, even if the driver does not intend to accelerate, if the accelerator is accidentally opened, the return of the gear position is not permitted, so the driver's intention can be more reliably determined. it can. Further, by waiting for permission to return the gear position for a predetermined time, it is possible to prevent a shift in a transient state from power-off to power-on. As a result, sudden torque fluctuations of the drive wheels can be suppressed, and the state can be stably shifted to the acceleration state. Such control is particularly effective on slippery road surfaces.

  In addition to the case where the accelerator opening is not fully closed for a predetermined time, for example, when the accelerator opening is not fully closed and the vehicle is changed to the right lane, that is, when a direction instruction to the right is issued. In addition, permission to return the gear position may be issued. In this case, since it can be determined that the driver has an intention of overtaking, the shift command unit 25 can reflect the driver's intention in the shift control when the shift stage permission is given, and the driver also feels uncomfortable. do not have.

  When the accelerator opening is not fully closed and the predetermined time or more has elapsed (step S111; Yes), the traveling state determination unit 22 grants a shift permission (step S112) and sets the flag F to zero. Thereafter, the above procedure is repeated and monitoring is continued. When the accelerator is not fully closed and the predetermined time or more has not elapsed (step S111; No), the inter-vehicle distance L and the accelerator opening are re-determined (steps S101, S102, S109).

  Here, the advantage of using the inter-vehicle time Ti for the vehicle arrival time will be described. As described above, when the shift command unit 25 issues a downshift command, the command is issued using the collision time Tc (inter-vehicle distance L / relative vehicle speed Vr (= own vehicle speed V1−preceding vehicle speed V2)). It can also be determined whether or not. However, when the collision time Tc is used as a control criterion, the collision time Tc is infinite when the relative vehicle speed Vr is 0 or close to 0 even when the inter-vehicle distance L is very small. become. Therefore, even if the shift control is performed so that the downshift is performed when the collision time Tc is equal to or less than the predetermined value, the downshift control is not executed when the relative vehicle speed Vr is near zero. On the other hand, if the inter-vehicle time Ti = L / V1 is used, the inter-vehicle time Ti becomes finite as long as the host vehicle 40 is traveling. For this reason, for example, if the threshold t1 is determined according to the own vehicle speed and the relative speed or the own vehicle speed and the inter-vehicle distance, the relative speed between the own vehicle 40 and the preceding vehicle 41 is close to zero. The downshift is appropriately executed, and the rapid approach between the host vehicle 40 and the preceding vehicle 41 can be sufficiently suppressed.

  An advantage of controlling the speed ratio return based on the inter-vehicle distance L will be described. As described above, the collision time Tc becomes infinite when the relative vehicle speed Vr approaches zero. If the gear ratio return permission is given when the collision time Tc is greater than the predetermined value, when the relative vehicle speed Vr is close to 0, the gear speed return permission is granted even when the inter-vehicle distance is extremely small. Will be given. For this reason, the collision time Tc cannot be used for the gear ratio return permission control. Here, according to the above-mentioned inter-vehicle time Ti, as long as the host vehicle 40 is traveling, the inter-vehicle time Ti becomes a finite size, so that such a problem does not occur. Therefore, the inter-vehicle time Ti can also be used for the gear ratio return permission control. However, in actual control, the output stage of the AT 10 is determined so that the relative vehicle speed Vr between the host vehicle 40 and the preceding vehicle 41 is near 0, and the gear ratio is restored when the relative vehicle speed Vr is near 0. This is substantially equivalent to setting the condition of the inter-vehicle distance L in the vicinity where the relative vehicle speed Vr becomes 0 and returning the gear ratio under that condition. For this reason, the use of the inter-vehicle distance L can simplify the gear ratio return control logic, and can realize control with excellent adaptability. Therefore, it is more advantageous to perform the speed ratio return control based on the inter-vehicle distance L because it becomes easier to apply to various driving conditions and control methods.

  As described above, according to the present invention according to this embodiment, since the return of the shift stage is permitted when a predetermined inter-vehicle distance is secured, for example, when the preceding vehicle 41 is accelerated and a sufficient inter-vehicle distance is secured. Can quickly return to a state in which driving can be performed according to the driver's intention. Also, downshifts are executed based on the inter-vehicle time, so even if the inter-vehicle distance is close and the relative speed between the preceding vehicle and the host vehicle is close to 0, the downshift is executed to ensure a sufficient inter-vehicle distance. it can. Furthermore, when the deceleration of the preceding vehicle is large, the number of steps of the downshift is increased, and in the case of a continuously variable transmission, the gear ratio is changed to a lower speed ratio, so that a sufficient inter-vehicle distance can be secured.

  As described above, the transmission control device for a transmission and the transmission control method for a transmission according to the present invention are useful for an automatic transmission, and in particular, it is not necessary to reduce the speed while controlling the transmission so as to maintain a sufficient inter-vehicle distance. Suitable for gear shifting control that can improve drivability at the time.

It is explanatory drawing which shows the transmission control apparatus of the transmission which concerns on the Example of this invention. It is a flowchart which shows the transmission control method of the transmission which concerns on the Example of this invention. It is explanatory drawing which shows the vehicle provided with the transmission control apparatus of the transmission which concerns on the Example of this invention, and a preceding vehicle. It is a conceptual diagram of the threshold value map of the inter-vehicle time with respect to the own vehicle speed and a relative vehicle speed. It is a conceptual diagram of the threshold value map of the inter-vehicle time with respect to the own vehicle speed and a relative vehicle speed. It is the schematic which shows the structure of AT which concerns on the Example of this invention. It is explanatory drawing which shows engagement relations, such as a clutch and a brake, with respect to the shift position of AT which concerns on the Example of this invention.

Explanation of symbols

10 AT (automatic transmission)
DESCRIPTION OF SYMBOLS 20 Control apparatus 20p Processing part 21 Map storage part 22 Running state determination part 23 Parameter calculation part 23 Comparison part 25 Shift command part 34 G sensor 36 Steering angle sensor 40 Own vehicle 41 Leading vehicle 42 Optical inter-vehicle distance sensor

Claims (5)

It controls the shift schedule of the transmission mounted on the vehicle,
A travel state determination unit that determines at least the accelerator opening state; and
A parameter calculation unit for obtaining a vehicle approach parameter for determining an approach between the preceding vehicle and the host vehicle based on a relative distance between the preceding vehicle and the host vehicle on which the transmission to be controlled is mounted;
A comparison unit that determines whether or not the host vehicle is approaching the preceding vehicle by comparing the vehicle approach parameter obtained by the parameter calculation unit with a predetermined threshold;
When the accelerator opening is fully closed and the vehicle approach parameter is less than or equal to the predetermined threshold value, the transmission gear ratio is changed to a lower speed gear ratio than the current state, and the relative distance is predetermined. A shift command unit that permits changing the gear ratio of the transmission to a gear ratio that matches the traveling state of the host vehicle, if greater than a value;
A transmission control device for a transmission, comprising:   A value obtained by dividing the inter-vehicle distance between the preceding vehicle and the own vehicle by the own vehicle speed, or a value obtained by dividing the inter-vehicle distance by the relative speed between the preceding vehicle and the own vehicle is used as the vehicle approach parameter. The transmission control device for a transmission according to claim 1.   Even when the inter-vehicle distance is smaller than the predetermined value, when the traveling state determination unit determines that the accelerator opening is larger than the fully closed state, the shift command unit matches the traveling state of the host vehicle. The shift control apparatus for a transmission according to claim 1 or 2, wherein a change in the transmission gear ratio of the transmission to a predetermined gear ratio is permitted.   The gear ratio of the transmission is changed to a lower speed ratio than the low speed ratio when the corner exists in the traveling direction of the preceding vehicle. The transmission control device for a transmission according to any one of claims 3 to 4. In controlling the shift schedule of the transmission installed in the vehicle,
Determining at least the accelerator opening state;
Obtaining a vehicle approach parameter for determining an approach between the preceding vehicle and the host vehicle based on a relative distance between the preceding vehicle and the host vehicle on which the transmission to be controlled is mounted;
Determining whether the host vehicle is approaching the preceding vehicle by comparing the vehicle approach parameter with a predetermined threshold value, and starting control;
When the accelerator opening is fully closed and the vehicle approach parameter is less than or equal to the predetermined threshold, the step of changing the transmission to a lower speed ratio than the current speed ratio;
When the relative distance is greater than or equal to a predetermined value, permitting a change to the gear ratio in accordance with the vehicle running state;
A transmission control method for a transmission, comprising:

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