JP2006226473A - Deceleration controller of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a vehicle so that the stability is not impaired when the vehicle is running in the condition that influences easily to the vehicle behavior as the whirling of the vehicle or the sliding of the tire are determined in the deceleration controller of the vehicle to control the speed reduction by gear change of a transmission. <P>SOLUTION: The deceleration controller of the vehicle by gear changing the transmission 10 comprises the first prediction means (S43) to predict the time when the running condition of the vehicle is easy to give the influence to the vehicle behavior, the second prediction means (S44) to predict the time when the gear change of the above transmission becomes the specified condition, and the control means to change the speed to the gear change step or gear change ratio that the above gear change becomes the specified condition until the time when the running condition of the above vehicle is easy to give the influence to the vehicle behavior on the basis of the time when the running condition of the above vehicle is easy to give the influence on the vehicle behavior and when the gear change of the above vehicle becomes the specified condition are prepared. . <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle deceleration control device, and more particularly to a vehicle deceleration control device that performs vehicle deceleration control by an operation of shifting a transmission to a relatively low speed gear stage or gear ratio.

  When vehicle deceleration control is performed based on conditions ahead of the vehicle, such as corner radius, road gradient, and inter-vehicle distance from the preceding vehicle, the shift stage of the automatic transmission is downshifted to reduce deceleration due to engine braking force. A technique of shift point control to be applied to a vehicle is known.

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

JP 2000-145937 A

  In a vehicle deceleration control device that performs deceleration control by shifting a transmission, the vehicle travels in a state in which the vehicle behavior is likely to be affected, such as when vehicle turning determination or tire slip determination is performed. It is desirable to control the vehicle so that the stability of the vehicle is not impaired. In this case, in particular, after the downshift command is output, it is necessary to perform control so that the vehicle stability is not adversely affected by the increase in deceleration.

  For example, when a vehicle turning determination or tire slip determination is made before a downshift command is output and the shift is started, the shift may be canceled. A shift command is output, and the shift may be executed halfway.

  An object of the present invention is a vehicle deceleration control device that performs deceleration control by shifting a transmission in a state in which vehicle behavior is likely to be affected, such as when vehicle turning determination or tire slip determination is performed. An object of the present invention is to provide a vehicle deceleration control device that performs control so that the stability of the vehicle is not impaired when the vehicle is traveling.

  A vehicle deceleration control device according to the present invention is a vehicle deceleration control device that performs deceleration by shifting a transmission, and predicts a point in time when the traveling state of the vehicle is likely to affect the vehicle behavior. Predicting means; second predicting means for predicting a point in time when the shift of the transmission is in a predetermined state; and a point in time when the running state of the vehicle is likely to affect the vehicle behavior and the shift of the transmission is predetermined. Control means for shifting to a gear stage or gear ratio at which the gear shift is in a predetermined state by a time point when the traveling state of the vehicle is in a state in which the vehicle behavior is likely to affect the vehicle behavior. It is characterized by that.

  In the vehicle deceleration control apparatus according to the present invention, the time point at which the traveling state of the vehicle is likely to affect the vehicle behavior is changed according to the detection accuracy of the current position of the vehicle.

  In the deceleration control device of the present invention, the vehicle deceleration control device is based on a driving environment including a manual shift command, information on corners or information on road gradient, or a driving state including an inter-vehicle distance with a preceding vehicle. The transmission is shifted.

  In the vehicle deceleration control apparatus according to the present invention, the traveling state of the vehicle that is likely to affect the vehicle behavior is a state in which the vehicle is entering a corner.

  In the vehicle deceleration control apparatus according to the present invention, the first predicting means may affect the vehicle behavior based on the road shape ahead, the vehicle speed, and the deceleration due to the shift speed or the gear ratio. It is characterized by predicting a point in time when it becomes easy.

  In the vehicle deceleration control apparatus according to the present invention, the vehicle running state that is likely to affect the vehicle behavior is a state in which the tire of the vehicle has a slip of a predetermined value or more.

  In the vehicle deceleration control apparatus according to the present invention, the first predicting means affects the vehicle behavior based on the road surface condition of the road ahead, the vehicle speed, and the deceleration by the gear stage or the gear ratio. It is characterized by predicting a time point at which it is easy to give a state.

  In the vehicle deceleration control apparatus according to the present invention, when the control means satisfies a condition that a friction coefficient of a road surface on which the vehicle travels is small, the travel state of the vehicle affects the vehicle behavior. It is characterized in that the shift is shifted to a shift stage or a gear ratio at which the shift is in a predetermined state by the time when the state becomes easy.

  In the vehicle deceleration control apparatus according to the present invention, the shift is in a predetermined state when the shift is started or completed.

  According to the vehicle deceleration control device of the present invention, in the vehicle deceleration control device that performs the deceleration control by shifting the transmission, the vehicle behavior is changed as when the vehicle turning determination or the tire slip determination is performed. When the vehicle is traveling in a state where it is easily affected, it is possible to perform control so that the stability of the vehicle is not impaired.

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

  As described above, when a vehicle turning determination is made after the downshift command for performing corner control is output and before the start of the shift (when it is determined that the vehicle is cornering) It is considered to cancel the shift. This is to suppress an increase in vehicle deceleration during cornering from the viewpoint of vehicle stability.

  In the above case, when it is determined whether or not the shift should be canceled based on the result of the actual vehicle turning determination, when it is determined that the vehicle is cornering as a result of the actual turning determination, the final determination is made. There is a possibility that a shift to be canceled is commanded and the shift operation is executed halfway. Therefore, when vehicle turning determination is performed, higher vehicle stability is required.

In the present embodiment, as the shift point control based on the front corner, at least in the control to change the speed and the gear ratio of the transmission to change the speed, based on the road shape and the vehicle speed and deceleration of the front,
The turning determination timing of the vehicle is predicted, and the turning determination timing is compared with the timing at which the speed change operation becomes a predetermined state (including the completion of shifting) to determine the presence or absence of deceleration control and the change of the upper limit gear position.

As the configuration of the present embodiment, (1) to (4) are assumed as will be described in detail below.
(1) Means for performing predetermined deceleration control by controlling at least a gear stage or a gear ratio of the transmission when the driver's intention to decelerate is detected for the front corner.
(2) Means for predicting the time when the vehicle reaches a predetermined turning degree at the corner based on the deceleration for each vehicle speed and gear and the shape of the road ahead.
(3) Means for detecting a maximum shift amount that is in a predetermined shift operation state before reaching the predetermined turning degree of (2).
(4) A means for determining the upper limit gear position based on the result of (3) above.

  In FIG. 2, reference numeral 10 denotes a stepped automatic transmission, 40 denotes an engine, and 200 denotes a brake device. The automatic transmission 10 is capable of six-speed shifting by controlling the hydraulic pressure by energization / non-energization of the solenoid valves 121a, 121b, and 121c. In FIG. 2, three electromagnetic valves 121a, 121b, and 121c are illustrated, but the number of electromagnetic valves is not limited to three. The solenoid valves 121a, 121b, and 121c are driven by a signal from the control circuit 130.

  The throttle opening sensor 114 detects the opening of the throttle valve 43 disposed in the intake passage 41 of the engine 40. The engine speed sensor 116 detects the speed of the engine 40. The vehicle speed sensor 122 detects the rotation speed of the output shaft 120c of the automatic transmission 10 that is proportional to the vehicle speed. The shift position sensor 123 detects the shift position. The pattern select switch 117 is used when instructing a shift pattern. The acceleration sensor 90 detects vehicle deceleration (deceleration acceleration). The steering angle sensor 93 is a sensor that detects the steering angle of a steering wheel (not shown).

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

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

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

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

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

  The manual shift determination unit 94 outputs a signal indicating the necessity of downshift (manual downshift) or upshift by the driver's manual operation based on the driver's manual operation. The inter-vehicle distance measuring unit 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 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 includes a throttle opening sensor 114, an engine speed sensor 116, a vehicle speed sensor 122, a shift position sensor 123, an acceleration sensor 90, a tire slip determination unit 91, a road surface μ detection / estimation unit 92, a steering angle sensor 93, a manual A signal indicating each detection result of the shift determining unit 94 and the inter-vehicle distance measuring unit 101 is input, a signal indicating the switching state of the pattern select switch 117 is input, and a signal from the navigation system device 95 is input.

  The control circuit 130 is configured by a known microcomputer and includes a CPU 131, a RAM 132, a ROM 133, an input port 134, an output port 135, and a common bus 136. The input port 134 includes signals from the sensors 93, 114, 116, 122, 123, 90, a signal from the switch 117, a signal from the navigation system device 95, a tire slip determination unit 91, and road surface μ detection. Signals from the estimation unit 92, the steering angle sensor 93, the manual shift determination unit 94, and the inter-vehicle distance measurement unit 101 are input. The output port 135 is connected to the electromagnetic valve driving units 138 a, 138 b, 138 c and a brake braking force signal line La to the brake control circuit 230. A brake braking force signal SG1 is transmitted through the brake braking force signal line La.

  The ROM 133 stores in advance a program in which the operations (control steps) shown in the flowchart of FIG. 1 are described, and a shift map for shifting the shift stage of the automatic transmission 10 and a shift control operation (not shown). ) Is 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 braking devices 208, 209, 210, and 211 provided on the wheels 204, 205, 206, and 207 of the vehicle, respectively. Each of the braking devices 208, 209, 210, and 211 controls the braking force of the corresponding wheels 204, 205, 206, and 207 when the hydraulic pressure is controlled by the hydraulic control circuit 220. The hydraulic control circuit 220 is controlled by the brake control circuit 230.

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

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

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

  FIG. 5 is a chart for explaining the deceleration control of the present embodiment. FIG. 5 shows a control execution boundary line Lb, a required deceleration 401, a target turning vehicle speed Vreq, a road shape top view, and a point a where the accelerator is OFF (the accelerator opening is fully closed).

[Step S10]
In step S10, the control circuit 130 determines whether or not the accelerator is in an OFF state (fully closed) based on a signal from the throttle opening sensor 114. If it is determined as a result of step S10 that the accelerator is in an OFF state, the process proceeds to step S20. When the accelerator is fully closed (step S10-Y), it is determined that the driver intends to decelerate, and the deceleration control of this embodiment is performed. On the other hand, if it is not determined that the accelerator is in the OFF state, the process proceeds to step S120. As described above, in FIG. 5, the accelerator opening is zero (fully closed) at the position (time point) a.

[Step S20]
In step S20, the control circuit 130 checks the flag F. As a result, if the flag F is 0, the process proceeds to step S30. If the flag F is 1, the process proceeds to step S50. If the flag F is 2, the process proceeds to step S60. When this control flow is executed, the flag F is initially 0, so the process proceeds to step S30.

[Step S30]
In step S30, the control circuit 130 determines whether or not this control is necessary based on, for example, the control execution boundary line Lb. In the determination, in FIG. 5, if it is located above the control execution boundary line Lb in relation to the current vehicle speed and the distance to the entrance c of the corner 402, it is determined that this control is necessary, and the control execution boundary line If it is located below Lb, it is determined that this control is unnecessary. As a result of the determination in step S30, if it is determined that this control is necessary, the process proceeds to step S40. If it is determined that this control is not necessary, this control flow is returned.

  In FIG. 5, the horizontal axis indicates the distance, and the other corner 402 exists from the point 403 to the point 404. A target turn corresponding to the radius (or curvature) R405 of the corner 402 at a point b that is offset by a predetermined amount from the entrance c of the corner 402 in order to turn the corner 402 at a preset desired turn G. It has to be decelerated to the vehicle speed Vreq. That is, the target turning vehicle speed Vreq is a value corresponding to R405 of the corner 402.

  The control execution boundary line Lb is a relationship between the current vehicle speed and the distance to the point b before the entrance c of the corner 402, as long as the deceleration exceeding the deceleration due to the normal braking set in advance does not act on the vehicle. This is a line corresponding to a range in which the target turning vehicle speed Vreq cannot be reached at the point b before the entrance c of the corner 402 (the corner 402 cannot be turned at the desired turning G). That is, when it is located above the control execution boundary line Lb, in order to reach the target turning vehicle speed Vreq at the point b before the entrance c of the corner 402, the deceleration by the normal braking set in advance is exceeded. It is necessary for the deceleration to act on the vehicle.

  Therefore, when the position is higher than the control execution boundary line Lb, the deceleration control corresponding to the corner R of the present embodiment is executed (step S46), and the brake operation amount by the driver is increased by the increase in the deceleration. Even if there is no control or the operation amount is relatively small (even if the foot brake is stepped on only a little), the target turning vehicle speed Vreq can be reached at the point b before the entrance c of the corner 402.

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

  In the present embodiment, in FIG. 5, the time point corresponding to the symbol a at which the accelerator opening is zero is located above the control execution boundary line Lb, so that it is determined that this control is necessary (step S30-Y). ), Go to step S40. In step S30, if it is determined that there is no corner ahead based on the data input from the navigation system device 95 by the control circuit 130, it is determined that this control is unnecessary.

[Step S40]
In step S40, the control circuit 130 determines the upper limit shift speed (downshift speed). Here, the upper limit shift stage means the shift stage after the downshift. The method for determining the upper limit gear position is shown in the flowchart of FIG.

[Step S42]
In step S42 of FIG. 3, the upper limit gear stage is provisionally determined based on the information on the previous corner R input from the navigation system device 95 and the road gradient measured or estimated by the road gradient measuring / estimating unit 118. In the provisional determination, the map shown in FIG. 4 is referred to. In this example, it is assumed that the upper limit gear position is provisionally determined as the third speed. Following step S42, step S43 is performed.

[Step S43]
In step S43, a time t ′ from when the turn is determined for each shift stage until the turning determination (determination that the vehicle is cornering) is made is predicted. Based on the shape of the road ahead, the current vehicle speed V, and the deceleration of each shift stage, the time at which the turn determination is made (time t ′ from the present until the turn determination is made) is predicted. Hereinafter, how to obtain the time t ′ will be described.

Based on the shape of the previous corner 402, the time point d at which the turning determination is performed can be estimated. For example, it is assumed that the turning determination is performed when the magnitude of the steering angle detected by the steering angle sensor 93 exceeds a predetermined value. First, the distance (L) until turning determination is obtained by the following equation 1.

  As described above, L3 (detection error of the current position detected by the navigation system device 95) is minus in Equation 1 in order to set L (distance until turning determination) as a small value. .

  Further, as shown in FIGS. 6A and 6B, the deceleration (α) at each gear stage is given on average as a function of the vehicle speed and the road gradient. FIGS. 6A and 6B show decelerations α1 and α2 when the shift speed is 5th and 4th, respectively, and the accelerator opening is fully closed. The deceleration α3 to α5 of the low speed stage is also obtained in the same manner although not shown.

  The vehicle speed (horizontal axis in FIGS. 6A and 6B) used for calculating the deceleration (α1 to α5) of each gear is, for example, the current vehicle speed (the vehicle speed at the accelerator-off point a) V It can be set to a value half the sum of the target turning vehicle speed Vreq. It is also possible to calculate the deceleration using only the current vehicle speed.

From the above, the time t ′ until the turning determination (determination that the vehicle is cornering) is made for each gear position from the relational expression (Formula 2) between the current vehicle speed V and the distance (step S43). .

  In addition, depending on the type of shift (multiple shift), there is a case where the output of a shift command is delayed in order to secure a shift sequence. In this case, the deceleration α can be calculated in consideration of the delay time being the deceleration of the gear stage before the gear shift. For example, when a multiple shift from the sixth speed to the fourth speed is performed, a shift from the fifth speed to the fourth speed is performed after the shift from the sixth speed to the fifth speed is performed. As described above, the shift command from the fifth speed to the fourth speed is output after a delay time corresponding to the time during which the shift from the sixth speed to the fifth speed is performed. The speed α is obtained in consideration of the occurrence of the deceleration α1 corresponding to the fifth speed during the delay time. In consideration of this, maps such as those shown in FIGS. 6A and 6B can be prepared for multiple shifts.

  Still further, particularly with respect to shifting to a low speed stage, in order to prevent engine overrun, the output of a shift command may be delayed until a predetermined vehicle speed is reached. Considering this, the deceleration α can be calculated in consideration of the deceleration of the gear stage before the shift until the predetermined vehicle speed is reached.

  In the above, in order to simplify the explanation, it has been explained that the deceleration α for each shift stage is given as a function of the vehicle speed and the road gradient on average. However, a strict sequential calculation may be performed. Of course.

In step S43, L3 can be changed based on the accuracy of determining the current position detected by the navigation system device 95. That is, immediately after the map matching of the navigation system device 95, since the accuracy of determining the current position is good, L3 is set to a small value. By setting L3 to a small value, it is possible to reduce the probability of prohibiting the shift even though the shift is actually completed before the turning determination is performed. On the other hand, after the map matching, the current position detection error L3 can be changed to a large value according to the travel distance or time.
After step S43, step S44 is performed.

[Step S44]
In step S44, a time t from when the shift command is output for each shift stage until the shift is completed is obtained. Depending on the type of shift, the time t from the shift command to the end of the shift can be estimated. The time t is given as a map value for each type of shift as shown in FIG.

[Step S45]
In step S45, an upper limit gear (downshift speed) is determined based on the results of steps S43 and S44. That is, when the turn determination (determination that the vehicle is cornering) obtained for each gear position in step S43 is performed (time t ′ from when the turn determination is made until now), to step S44. Then, the time t from the shift command obtained for each shift stage to the completion of the shift is compared for each shift stage, and the shift stage at which the shift is completed by the time when the turning determination is performed is obtained.

  As a result of the comparison for each gear, if the shift to the provisionally estimated upper limit gear (third speed in this example) is completed by the time when the turning determination is performed, the provisionally estimated upper limit gear The step is determined as the upper limit shift step (step S45). On the other hand, if the shift to the temporarily estimated upper limit shift stage is not completed by the time when the turning determination is performed, the shift stage is completed by the time when the turning determination is performed, and the temporary estimated The gear closest to the upper limit gear is determined as the upper gear (step S45).

  For example, the current speed is 6th speed, and as a result of the comparison for each gear position, t <t ′ is obtained when shifting from 6th speed to 4th speed, and t> t ′ is achieved when shifting from 6th speed to 3rd speed. In this case, the upper limit gear is determined to be the fourth speed. When a shift command from the 6th speed to the 4th speed is output, the shift can be completed before the turning determination is performed. That is, as can be seen from the result of the comparison, when a shift command from the 6th speed to the 3rd speed is output, a turning determination is made during the shift from the 4th speed to the 3rd speed, and as a result, the shift is canceled. However, in this embodiment, such inconvenience is avoided. Note that, when the upper limit gear is a gear greater than or equal to the current gear, the downshift control according to the present embodiment is not performed. After step S45, step S46 is performed.

[Step S46]
In step S46, a shift command to the upper limit gear determined in step S45 is output. In this example, a shift command from 6th speed to 4th speed is output. Following step S46, step S50 of FIG. 1 is performed.

[Step S50]
In step S50, the control circuit 130 determines whether or not the vehicle has entered the corner 402 (vehicle turning determination). The control circuit 130 performs the determination in step S50 based on the steering angle value, the lateral G size of the vehicle, and the like. Alternatively, the determination in step S50 is performed based on data input from the navigation system device 95 and indicating the current position of the vehicle and the position of the entrance c of the corner 402. As a result of the determination in step S50, if it is after entering the corner 402, the process proceeds to step S60, and if not, the process proceeds to step S55.

  In the first stage in which this control flow is implemented, since the vehicle has not entered the corner 402 (step S50-N), the presence / absence of tire slip is determined in step S55.

[Step S55]
In step S55, the presence or absence of tire slip is determined by the control circuit 130 based on the signal input from the tire slip determination unit 91. As a result of the determination, if it is determined that there is tire slip, the process proceeds to step S60, and if not, the process proceeds to step S100.

  In step S55, it is determined whether or not the road surface is a low μ road based on not only the presence or absence of tire slip but also the signal input from the road surface μ detection / estimation unit 92. If it is determined that the road is a μ road, the process proceeds to step S60. If it is determined not to be any case, the process may proceed to step S100.

[Step S100]
In step S100, the flag F is set to 1, and this control flow is reset. In the control flow again, when the accelerator is fully closed (step S10-Y), since the flag F is 1 (step S20-1), the process proceeds to step S50 and is repeated until the condition of step S50 is satisfied. It is.

[Step S60]
In step S60, the control circuit 130 restricts new upshifts and downshifts. During cornering after entering the corner 402, the gear may be upshifted to a higher gear than the gear associated with the downshift command output in step S46 (fourth gear in the above example). Be regulated. Normally, even in a shift point control for a general corner, an upshift during cornering after entering the corner is prohibited. Further, regarding downshifting, during cornering after entering the corner 402, it is restricted that the downshifting is performed at a lower speed than the gear associated with the downshift command output in step S46. Is done. This is because during cornering or when there is tire slip, an increase in deceleration is prevented, contributing to vehicle stability. After step S60, the process proceeds to step S70.

[Step S70]
In step S <b> 70, the control circuit 130 determines whether or not the vehicle has escaped from the corner 402. The control circuit 130 determines whether or not the vehicle has escaped from the corner 402 based on the steering angle value or the lateral G acting on the vehicle. Alternatively, based on the data input from the navigation system device 95 and indicating the current position of the vehicle and the position of the exit 404 of the corner 402, the determination in step S70 is performed. If it is after exiting the corner 402 as a result of the determination in step S70, the process proceeds to step S80, and if not, the process proceeds to step S110.

  Since the vehicle has not escaped from the corner 402 at the first stage when this control flow is executed (step S70-N), the flag F is set to 2 in step S110, and this control flow is reset. In the control flow again, when the accelerator is fully closed (step S10-Y), since the flag F is 2 (step S20-2), new upshifts and downshifts remain restricted ( Step S60) is repeated until the condition of Step S70 is satisfied. If the condition of step S70 is satisfied (step S70-Y), the process proceeds to step S80.

[Step S80]
In step S80, the shift restriction is canceled by the control circuit 130. As a result, the restriction on the upshift and the downshift performed in step S60 is released. Following step S80, step S90 is performed.

[Step S90]
In step S90, the control circuit 130 sets the flag F to 0. After step S90, this control flow is reset.

[Step S120] to [Step S140]
Before the deceleration control of the present embodiment is started (with flag F = 0), if the accelerator is not fully open (step S10-N), it is determined whether cornering is being performed (step S120). If the result of the determination is cornering (step S120-Y), this control flow is reset. When cornering is not in progress (step S120-N), the shift restriction is canceled (step S130), and the flag F is cleared and reset (step S140). Note that in the initial state when this control is started, the shift is not restricted and the flag F is also 0, so it remains as it is.

  If the determination in step S50 is negative and the determination in step S55 is negative, or the determination is negative in step S70 and the accelerator is depressed while waiting for a positive determination In the case (step S10-N), the determination in step S120 is performed, and necessary measures are taken according to the determination result.

  According to the present embodiment, since the shift command to the shift stage where the shift is completed is output by the time when the vehicle turning determination (determination that the vehicle is cornering) is performed, There is no possibility that the shift command is canceled or the shift operation is executed halfway in relation to the turning determination. Thereby, higher vehicle stability is obtained.

(First modification of the first embodiment)
In the first embodiment, the corner control is described as being performed by controlling the gear position of the stepped automatic transmission 10, but instead, the control of the gear ratio of the CVT can be performed.

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

  In the above description, the required deceleration is a deceleration required to turn the other corner at a predetermined desired turn G (in order to enter the corner at a desired vehicle speed Vreq). In FIG. 5, the necessary deceleration is indicated by reference numeral 401.

  In order to decelerate from the vehicle speed at the location a where the accelerator is determined to be fully closed in step S10 to the target turning vehicle speed Vreq required at the point b just before the entrance c of the corner 402, the required deceleration 401 is indicated. Such deceleration is required. The control circuit 130 is based on the current vehicle speed input from the vehicle speed sensor 122, the distance from the current position input from the navigation system device 95 to the entrance c (point b before) of the corner 402, and R405 of the corner 402. The necessary deceleration 401 is calculated.

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

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

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

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

(Third Modification of First Embodiment)
In step S43 of the first embodiment, the time at which the turning determination is performed (time t ′ from when the turning determination is performed to the present time) is estimated. Instead, in this modification, for example, the degree of turning Alternatively, the time point when the lateral G acting on the vehicle becomes a predetermined value or the time point when the turning starts (for example, corresponding to the entrance c of the corner 402) may be estimated.

(Fourth modification of the first embodiment)
In step S44 of the first embodiment, the time t from when the shift command is output until the shift is completed is obtained. However, in this modification, the shift is performed in a predetermined state (shift) after the shift command is output. In Step S45, the time can be compared with the time t ′ in Step S43.

(Fifth Modification of First Embodiment)
In steps S43 and S44 of the first embodiment, the obtained times are compared, but distances may be compared instead.

(Sixth Modification of First Embodiment)
A sixth modification of the first embodiment will be described with reference to FIG.

  In this modification, as shown in FIG. 8, only when the road surface μ detection / estimation unit 92 determines that the road surface μ is equal to or smaller than a predetermined value (step S42a), the upper limit shift temporarily determined in step S42. Stage correction (steps S43 to S45) is performed. This is because, when it is determined that the road surface μ is equal to or less than the predetermined value, it is particularly required to ensure vehicle stability. When it is not determined that the road surface μ is equal to or smaller than the predetermined value, a shift command for instructing a shift with respect to the upper limit gear temporarily determined in step S42 is output (step S46).

(Second Embodiment)
A second embodiment will be described with reference to FIG.
In the second embodiment, the description of the same points as in the first embodiment will be omitted.

  In the first embodiment, with respect to the downshift command as the deceleration control (corner control) based on the size of the other corner, the shift is performed before the turning determination (determination that the vehicle is cornering) is performed. A shift command for shifting to a completed shift stage is issued.

  In other words, in the first embodiment, the shift is determined based on the timing at which the turn determination obtained for each shift stage is performed (time t ′ from when the turn determination is performed until now) and the shift command obtained for each shift stage. The time t until completion is compared for each shift speed, the shift speed that completes the shift by the time when the turning determination is performed is obtained, and as a result of the comparison for each shift speed, the temporarily estimated upper limit shift speed If the shift to (the third speed in this example) is completed by the time when the turning determination is performed, the provisionally estimated upper limit shift stage is determined as the upper limit shift stage, and the provisionally estimated upper limit shift stage If the shift to is not completed by the time when the turning determination is made, the speed that is completed by the time when the turning determination is made, and the speed closest to the tentatively estimated upper limit is the upper limit. It was determined as the gear position.

  On the other hand, in the second embodiment, manual shift, corner control, deceleration control (uphill / downhill control) performed in response to a road gradient, or deceleration control (follow-up control) performed in response to an inter-vehicle distance. With respect to the downshift command based on this, a gearshift command is issued to shift to a gear position where the gearshift is completed before reaching the region where tire slip occurs.

  The operation of the second embodiment will be described with reference to FIG.

[Step S42]
In step S42, the control circuit 130 determines whether or not a downshift command is output based on manual shift, corner control, uphill / downhill control, and follow-up control. If any downshift command is output, The gear position after the shift based on the downshift command is provisionally determined as the upper limit gear position. When a plurality of downshift commands are output at the same time, the lowest gear is provisionally determined as the upper limit gear.

  In the above, the downshift command based on the manual shift is output based on the driver's manual operation when the driver desires to apply the deceleration by shifting the automatic transmission 10 in the direction in which the engine brake is applied, It is detected by the manual shift determining unit 94. The downshift command based on the uphill / downhill control is output based on the road gradient measured or estimated by the road gradient measurement / estimation unit 118. The downshift command based on the follow-up control is output based on the inter-vehicle distance measured by the inter-vehicle distance measuring unit 101. Step S43 is performed after step S42.

[Step S43]
In step S43, a time ta ′ until reaching the region where tire slip occurs for each gear position is predicted. Here, the information indicating the region where the tire slip occurs can be provided to the vehicle from the infrastructure (industrial infrastructure such as a road) or can be provided to the vehicle as the navigation information. The time when tire slip occurs (time ta ′ until reaching the region where tire slip occurs) is based on information indicating the region where tire slip occurs, the current vehicle speed V, and the deceleration of each gear. ,is expected. A method for obtaining the time ta ′ will be described.

  The time point at which the tire slip occurs can be estimated based on the information indicating the region where the tire slip occurs. First, the distance (L) until the tire slip occurs is obtained by subtracting L3 (the detection error of the current position detected by the navigation system device 95) from the distance until the tire slip occurs.

  From the above, from the relational expression (current formula 2) between the current vehicle speed V and the distance, the time ta ′ until reaching the region where the tire slip occurs is obtained for each gear (step S43). After step S43, step S44 is performed.

[Step S44]
In step S44, referring to FIG. 7, a time t from when the shift command is output for each shift stage until the shift is completed is obtained.

[Step S45]
In step S45, an upper limit gear (downshift speed) is determined based on the results of steps S43 and S44. That is, the timing at which the tire slip occurs for each gear position in step S43 (time ta ′ from the current time until reaching the region where the tire slip occurs) is obtained for each gear position in step S44. The time t from when the gear change command is received until the gear shift is completed is compared for each gear position, and the gear position at which the gear shift is completed by the time when the tire slip occurs is obtained.

  As a result of the comparison for each gear, if the gear shift to the temporarily estimated upper limit gear (third speed in this example) is completed by the time when tire slip occurs, the provisionally estimated upper limit gear The step is determined as the upper limit shift step (step S45). On the other hand, if the shift to the temporarily estimated upper limit shift stage is not completed by the time when tire slip occurs, the shift stage is completed by the time when tire slip occurs, and the provisionally estimated The gear closest to the upper limit gear is determined as the upper gear (step S45). After step S45, step S46 is performed.

[Step S46]
In step S46, a shift command to the upper limit gear determined in step S45 is output.

  According to the present embodiment, since the shift command to the shift stage where the shift is completed is output by the time when the tire slip determination of the vehicle (determination that the vehicle has tire slip) is performed, There is no possibility that the shift command is canceled or the shift operation is executed halfway in relation to the tire slip determination of the vehicle. Thereby, higher vehicle stability is obtained.

  The first embodiment and the second embodiment can be appropriately combined. For example, when both vehicle turning determination and tire slip determination are predicted, the gear position at which the shift is completed by the earlier of the time when the vehicle turning determination and the tire slip determination are performed, whichever comes first Can be determined as the upper limit gear.

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

  From the above embodiments, the following items are disclosed.

(Claim 1)
When the driver's intention to decelerate is detected with respect to the other corner, the speed reduction control is performed by shifting at least the transmission to the upper limit gear stage (including those for cooperatively controlling the brake and MG) as necessary. A vehicle deceleration control device that performs prediction based on a shape of a road ahead, a vehicle speed, and a deceleration at each shift stage, and predicts a time when the vehicle has a predetermined turning degree with respect to a corner. A vehicle deceleration control device, comprising: comparing a timing with a timing at which a shift operation reaches a predetermined state (including completion of a shift), and determining whether or not deceleration control is performed and an upper limit shift stage.

(Section 2)
If the driver's intention to decelerate is detected at the other corner, the gear ratio is changed to at least the high-side gear ratio at the upper limit of CVT as necessary (including those that coordinately control the brake and MG). A vehicle deceleration control device that performs deceleration control by predicting when the vehicle has a predetermined turning degree with respect to a corner based on the shape of the road ahead, the vehicle speed, and the deceleration at each gear stage. A vehicle deceleration control device, which determines the presence or absence of deceleration control and the upper limit high-side transmission ratio by determining the transmission ratio of the CVT that can be reached by the predicted time.

(Section 3)
The vehicle deceleration control device according to Item 1 or 2, wherein the distance used for obtaining the time when the predetermined turning degree is obtained is changed based on the estimated accuracy of the current position of the navigation. Deceleration control device.

(Claim 4)
If the driver's intention to decelerate is detected in response to a manual downshift command or a downshift command based on uphill / downhill control or follow-up control, the transmission is shifted to at least the upper limit gear as necessary (further. A vehicle deceleration control device that performs deceleration control by controlling the brake and MG in a coordinated manner), based on information indicating the road surface condition of the road ahead, vehicle speed, and deceleration at each gear stage The vehicle is predicted when the vehicle reaches the region where the tire slip occurs, and the predicted timing is compared with the timing when the speed change operation reaches a predetermined state (including completion of the speed change). The vehicle deceleration control device is characterized in that the presence or absence and an upper limit gear position are determined.

(Section 5)
If a driver's intention to decelerate is detected in response to a manual downshift command or a downshift command based on uphill / downhill control or follow-up control, the gear ratio is set to at least the upper CVT high-side gear ratio as necessary. Is a vehicle deceleration control device that performs deceleration control by changing the vehicle speed (including those that coordinately control the brake and MG), information indicating the road surface condition of the destination road, vehicle speed, and each gear position Based on the deceleration of the vehicle, the time when the vehicle reaches the region where the tire slips is predicted, and the CVT transmission ratio that can be reached by the predicted time is obtained. A vehicle deceleration control device that determines a high-side gear ratio of the vehicle.

(Claim 6)
The vehicle deceleration control device according to the item 4 or 5, wherein the distance used for obtaining the time to reach the region where the tire slip occurs is changed based on the estimated accuracy of the current position of the navigation. A vehicle deceleration control device.

It is a flowchart which shows operation | movement 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. It is a flowchart which shows other operation | movement of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. 3 is a map used for provisional determination of an upper limit gear position in the first embodiment of the vehicle deceleration control device of the present invention. It is a figure for demonstrating the effect of 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 and road gradient when the gear stage is 5th speed 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 and road gradient when the gear stage is 4th speed in 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a figure which shows the time from the transmission command for every kind of transmission in the 1st Embodiment of the deceleration control apparatus of the vehicle of this invention to the completion of transmission. It is a flowchart which shows operation | movement of the 6th modification of 1st Embodiment of the deceleration control apparatus of the vehicle of this invention. It is a flowchart 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 91 Tire slip determination part 92 Road surface micro | micron | mu. Detection / estimation part 93 Steering angle sensor 94 Manual shift determination part 95 Navigation system apparatus 101 Inter-vehicle distance measurement part 114 Throttle opening sensor 116 Engine rotation speed sensor 118 Road gradient measurement / estimation unit 122 Vehicle speed sensor 123 Shift position sensor 130 Control circuit 131 CPU
133 ROM
200 Brake Device 230 Brake Control Circuit 401 Necessary Deceleration 402 Corner 404 Corner Exit 405 Corner R
a Accelerator off point b Point offset from the corner entrance c Corner entrance d Time point when turning is determined Vreq Target turning vehicle speed L1 Time point when it is determined that the vehicle is cornering after entering the corner L2 Navigation system Distance from current position determined by device to corner approach L3 Error (offset) related to current position determined by navigation system device
La Brake braking force signal line Lb Control execution boundary line SG1 Brake braking force signal SG2 Brake control signal

Claims (9)

A vehicle deceleration control device that performs deceleration by shifting a transmission,
First prediction means for predicting a point in time when the traveling state of the vehicle is in a state in which the vehicle behavior is likely to be affected;
Second predicting means for predicting a time point at which the shift of the transmission is in a predetermined state;
Based on the time when the traveling state of the vehicle is likely to affect the vehicle behavior and the time when the shift of the transmission is in a predetermined state, the traveling state of the vehicle is likely to affect the vehicle behavior. A vehicle deceleration control device comprising: control means for shifting to a gear stage or gear ratio at which the gear shift is in a predetermined state by a time point. The vehicle deceleration control device according to claim 1,
The vehicle deceleration control device, wherein the time point at which the traveling state of the vehicle is likely to affect the vehicle behavior is changed according to the detection accuracy of the vehicle navigation system. The vehicle deceleration control device according to claim 1 or 2,
The vehicle deceleration control device shifts the transmission based on a driving environment including a manual shift command, information on corners or information on road gradient, or a driving state including an inter-vehicle distance from a preceding vehicle. A vehicle deceleration control device characterized by the above. The vehicle deceleration control device according to any one of claims 1 to 3,
The vehicle running state, which is a state in which the vehicle behavior is easily affected, is a state in which the vehicle is entering a corner. The vehicle deceleration control device according to claim 4,
The first predicting means predicts a time point at which the traveling state of the vehicle is likely to affect the vehicle behavior based on the road shape of the destination, the vehicle speed, and the deceleration due to the shift speed or the gear ratio. A vehicle deceleration control device characterized by the above. The vehicle deceleration control device according to any one of claims 1 to 3,
The vehicle running state in which the vehicle behavior is likely to be affected is a state in which the tire of the vehicle has a slip of a predetermined value or more. The vehicle deceleration control device according to claim 6,
The first predicting means predicts a time point when the traveling state of the vehicle is likely to affect the vehicle behavior based on the road surface condition of the road ahead, the vehicle speed, and the deceleration by the gear stage or the gear ratio. A vehicle deceleration control device characterized by the above. The vehicle deceleration control device according to any one of claims 1 to 7,
The control means, when satisfying the condition that the friction coefficient of the road surface on which the vehicle is traveling is in a small state, the shift is performed until the time when the traveling state of the vehicle is in a state where the vehicle behavior is likely to be affected. A vehicle deceleration control device, wherein the vehicle is shifted to a gear stage or a gear ratio that is in a predetermined state. The vehicle deceleration control device according to any one of claims 1 to 8,
The vehicle speed reduction control device characterized in that the shift is in a predetermined state is that the shift is started or completed.

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