JP2780390B2 - Automatic transmission control device for vehicle equipped with traction control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission control device that automatically switches a gear position of an automatic transmission in relation to a traveling state of a vehicle in a vehicle provided with a traction control device. It is.

2. Description of the Related Art A gear position of an automatic transmission is selectively selected from one of a plurality of gear positions in relation to an actual vehicle traveling state, for example, a throttle valve opening and a vehicle speed of a vehicle, from a shift diagram stored in advance. There is known an automatic transmission control device that switches to the automatic transmission. In some cases, a vehicle provided with the automatic transmission control device is provided with a so-called traction control device for preventing a drive wheel from slipping during an acceleration operation. However,
In a conventional automatic transmission control device provided with a traction control device, when slippage of a drive wheel is detected, traction control is started to prevent the slippage, and the driving force is suppressed, so that the automatic transmission is controlled. Because the gear ratio can be rapidly changed, regardless of the driving force control,
Due to the lack of responsiveness of the driving force control, a sudden change in the driving force occurs. For this reason, there is an inconvenience that the slip of the drive wheels increases in association with the change in the gear ratio of the automatic transmission, even during the control for suppressing the slip.

On the other hand, when the traction control for preventing the acceleration slip of the drive wheels is started as in the vehicle slip prevention device described in JP-A-1-136834, the engine output is reduced and the transmission It is conceivable to eliminate the inconvenience that the slip of the drive wheels becomes large due to the lack of responsiveness of the driving force control caused by the rapid change of the gear ratio by performing the shift more slowly than usual.

Problems to be Solved by the Invention However, in the above-described shift control device, when the traction control is started, the shift is performed more gently than normal regardless of the running state of the vehicle, so that the vehicle is driven on a road surface having a small road surface frictional resistance. If the traction control is started during running, the engine speed will be high and the gear shift will be performed in a state where the inertia on the engine side is large, so the slip of the drive wheels will increase despite the traction control There was a problem.

Means for Solving the Problems The present invention has been made in the background of the above circumstances, and the gist of the invention is that, when the driving wheel slips when accelerated by the acceleration operating member, What is claimed is: 1. An automatic transmission control apparatus, comprising: a vehicle provided with a traction control device that suppresses a driving force so as to prevent a slip; (A) road surface μ estimation calculating means for calculating an estimated road surface frictional resistance value; and (b) shift determination based on the actual vehicle shift position and the estimated road surface frictional resistance value calculated by the road surface μ estimation calculating means. A shift determining vehicle speed determining means for determining a vehicle speed; and (c) an actual vehicle speed of the vehicle is determined by the shift determining vehicle speed determining means during driving force suppression by the traction control device. And upon reaching the shift decision vehicle speed lies in containing a speed width limiting means for permitting limited the single shift width of the automatic transmission to a single gear.

In this manner, the shift determining vehicle speed is determined by the shift determining vehicle speed determining means based on the actual vehicle shift position and the estimated road surface frictional resistance value calculated by the road surface μ estimation calculating means. In addition, when the actual vehicle speed of the vehicle reaches the shift determination vehicle speed during the driving force suppression by the traction control device, one shift width of the automatic transmission is limited to one gear by the shift width limiting means. Allowed. For this reason, one shift width of the automatic transmission is limited to one gear position, so that a sudden change in the driving force due to a large change in the gear ratio does not occur, and the shift of the automatic transmission during the traction control is performed. The spread of the associated drive wheel slip is prevented. Also, the shift determination vehicle speed used when the shift of the automatic transmission is permitted by the shift width limiting means is:
Since the speed is determined on the basis of the actual vehicle shift position and the estimated road frictional resistance value, the speed change determination vehicle speed is determined to be a small value on a road surface having a low road frictional resistance, so that the engine rotation speed is not increased. On the road surface where the road surface friction resistance is not so small, the shift determination vehicle speed is determined to be a large value as compared with the road surface where the road surface friction resistance is small, Acceleration of the vehicle can be maintained.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 2, the output of the engine 10 is transmitted to drive wheels (rear wheels) 18 via a torque converter 12, a planetary gear type stepped transmission 14, and a differential gear device 16. The intake pipe 20 of the engine 10 is rotated by a first throttle valve 24 which is connected to an accelerator pedal 22 and is rotated to an opening degree corresponding to a stepping operation amount thereof, and a throttle actuator 26 formed by a step motor and the like. A second throttle valve 28 is arranged in series. They opening theta _S of the first throttle valve 24 opening theta _M and the second throttle valve 28, while being detected by the main throttle opening sensor 30 and the sub-throttle opening sensor 32, their opening theta _M and The signal representing θ _S is a combustion control electronic control unit (hereinafter referred to as EFICU) 34
And electronic control unit for traction control (hereinafter referred to as TRCECU
To 36) respectively.

The rotational speeds of a pair of front wheels 38 of the vehicle are detected by a pair of front wheel speed sensors 40, and a signal representing the rotational speeds is supplied to TRCECU 36. The rotation speed N _E of the engine 10 is adapted to be detected by the engine rotational speed sensor 44, a signal indicating the engine rotational speed N _E is, TRCECU36 and automatic transmission control electronic control unit (hereinafter, referred ECTECU ) Supplied to 46). Also, stepped transmission
14 output shaft rotation speed (that is, rotation speed of rear wheel 18) N _OUT
Is detected by a vehicle speed sensor 48,
The signal indicating the output shaft rotation speed N _OUT is TRCECU36 and
Supplied to ECTECU46. Further, a shift position sensor 42 for detecting an actual shift position is provided in the stepped transmission 14, and a signal indicating an actual gear position is supplied to the ECTECU 46.

The above-mentioned EFICU34, TRCECU36, and ECTECU46 are CPU, R
The CPU is configured by a so-called microcomputer including an AM and a ROM. The CPU processes an input signal according to a program stored in the ROM in advance while using a storage function of the RAM, and outputs a predetermined output.

For example, the EFIECU34, determines the basic injection time based on the actual engine rotational speed N _E and the intake air amount or the intake pipe negative pressure from a pre-stored relationship, the magnitude of the throttle opening theta _M in the basic injection time And a correction based on the rate of change is applied.
Is output. Further, the throttle opening theta _M is when it becomes a minimum, the drive signal for closing the fuel injection valve 50 in order to save fuel is output when the predetermined vehicle speed or more. If a slip occurs on the drive wheel 18 during the start acceleration operation, the drive wheel 18
In order to suppress the rotation torque of 18, a signal for delaying the ignition timing of the ignition plug 52 and a drive signal for closing the fuel injection valve 50 are output. In EFIECU34, the first
The smaller of the opening θ _M of the throttle valve 24 and the opening θ _S of the second throttle valve 28 is determined, and a signal representing the smaller opening is supplied to the ECTECU 46.

Further, for example, in the TRCECU 36, the slip ratio S of the rear wheel 18 is obtained from the rotational speed difference between the rear wheel 18 and the front wheel 38, and the slip ratio S is determined by the driving force and the lateral drag of the rear wheel 18 during the acceleration operation of the vehicle. A drive signal for driving the throttle actuator 26 is output so as to fall within the range obtained together, and a signal for requesting the retard and the fuel cut is output to the EFICU 34.

Further, the ECTECU46, determined actual shift diagram corresponding to the gear stage from the shift diagram of a plurality of types stored in advance for each gear position, opening theta _M and the first throttle valve 24 from the shift diagram the second upshift or downshift on the basis of the opening degree and the traveling speed of the smaller of the opening theta _S of the throttle valve 28 is determined, the solenoid valve of the transmission signal is stepped transmission 14 for changing the gear And also to TRCECU36. If the traction control (TRC control) is not being performed, the second throttle valve 2
Opening theta _S 8 is maintained fully open. While the shift prohibition request signal is being supplied from the TRCECU 36, the output of the shift signal for switching the gear is stopped.

FIG. 1 is a block diagram for explaining the functions of the EFICU34, TRCECU36, and ECTECU46. In the throttle opening degree changing means 60, switching the throttle opening degree for use in automatic shift control to the smaller opening ones opening theta _S of the first throttle valve 24 opening theta _M and the second throttle valve 28 Can be The shift position calculating means 62 determines a shift position (for example, a target gear position) based on the switched throttle valve opening and running speed (output shaft rotation speed N _OUT ) from a shift diagram stored in advance. Then, the shift position control unit 64 outputs a shift signal to the stepped transmission 14 so that the above-described shift position matches the actual shift position detected by the shift position sensor 42 functioning as the shift position detecting unit. You. On the other hand, in the acceleration slip detecting means 66, the driven wheel speed detected by the front wheel speed sensor 40 and the vehicle speed sensor
The slip ratio S is obtained from the rotational speed difference from the drive wheel speed detected by 48, and the throttle actuator 26 is driven such that the slip ratio S falls within a predetermined range in which the driving force and the lateral drag are compatible. You. This throttle actuator 26 functions as throttle control means. When a signal indicating that an acceleration slip is being performed is supplied from the acceleration slip detection means 66 to the shift inhibition command means 68, a shift inhibition request signal for requesting inhibition of gear change during the acceleration slip is issued. It is supplied from the prohibition command means 68 to the shift position control means 64. On the other hand, the road surface μ estimation calculating means 70 calculates the friction coefficient μ of the traveling road surface based on the driven wheel speed, and the shift determination vehicle speed determining means 72 calculates the actual friction coefficient μ of the traveling road surface and the actual friction coefficient μ. Is determined based on the gear stage. When the actual vehicle speed of the vehicle reaches the shift determination vehicle speed determined by the shift determination vehicle speed determination unit 72, the shift width limiting unit 74 limits the single shift width of the stepped transmission 14 to one gear position. Then, the shift is permitted, and a shift prohibition request signal is supplied to the shift prohibition command means 68 so that the shift is performed when the shift is permitted. Thus, the shift is performed at the shift timing at which the suppression of the acceleration slip and the acceleration of the vehicle are compatible.

Hereinafter, the main part of the control operation of the EFICU 34, TRCECU 36, and ECTECU 46 will be described with reference to the flowcharts of FIGS. 3, 4, 5, and 6.

FIG. 3 shows a shift prohibition request routine in the TRCECU 36. In the figure, in step 100, it is determined whether the TRC control for controlling the driving torque of the driving wheel 18 is performed so that the slip ratio S of the driving wheel 18 during the acceleration operation falls within a predetermined range in which the driving force and the lateral drag are compatible. It is determined whether or not. If it is determined in step 100 that the TRC control is not being performed, the content of the TRC signal output to indicate that the TRC control is being performed is turned off in step 210, and in step 22
At 0, the content of the SHIFT permission signal output to shift to the shift position determined by the ECTECU 46 is turned ON. This SHIFT permission signal is transmitted to the stepped transmission 1 by ECTECU46.
The signal for permitting the shift control of the fourth gear stage, that is, a signal for permitting a change operation of the shift position of the stepped transmission 14, and when the content is OFF, a shift inhibition request is issued from the TRCECU 36 to the ECTECU 46. It is in the state that it is.

However, if it is determined in step 100 that the TRC control is being performed, the content of the TRC signal is turned on in step 110, and it is determined in step 120 whether the content of the SHIFT permission signal is off. Is done. If it is determined in step 120 that the content of the SHIFT permission signal is not OFF, it is determined in step 130 whether or not the TRC control is being performed in the previous cycle. It is determined whether or not the shift position has changed. When it is determined in step 130 that the TRC control is not being performed in the previous cycle, or in step 130 and step 1
If both of the determinations in step 40 are affirmed, the content of the SHIFT permission signal is turned off in step 150, and a shift prohibition request state is set. If it is determined that the shift position of the transmission 14 has not changed, the present routine ends.

If it is determined in step 120 that the content of the SHIFT permission signal is OFF, steps 160 and subsequent steps are executed to issue a shift permission. First, step 160
In step 170, it is determined whether the OFF state of the SHIFT permission signal has continued for 1 second or more, and in step 170, it is determined whether the average value of the step amount ΔV _ave is equal to or less than a predetermined value, for example, 2 km / h. You. The average value ΔV _ave of the slip amount is repeatedly calculated in a fixed short cycle by, for example, an interrupt routine shown in FIG. That is, in FIG. 4, in step 300, the slip amount ΔV is calculated by subtracting the control target vehicle speed V _T plus target slip amount to the vehicle speed based on the rotation of the driven wheels 38 from the drive wheel speed V _F, step 310 Then, the slip amount ΔV calculated in each cycle is sequentially added, and in step 320, “1” is added to the content of the counter CN for calculating the average value. Then, in step 330, it is determined whether or not the content of the counter CN has reached a predetermined constant value N,
When it is determined that the current value has not reached the predetermined time, the present interrupt routine is terminated. However, when it is determined that the current value has reached the predetermined value, in step 340, the sum of the average values up to that point is divided by the number of added values N. As a result, the average value ΔV _ave of the slip amount is calculated, the content of the addition is cleared to “0” in step 350, and the content of the counter CN is cleared to “0” in step 360.

Returning to FIG. 3, it is determined in step 160 that the OFF state of the SHIFT permission signal has not been continued for one second or more.
Alternatively, in step 170, the average slip amount ΔV _ave
Is determined to be less than or equal to 2 km / h, this routine is terminated.However, if the determinations in steps 160 and 170 are both affirmed, in step 180, the actual shift position, the shift determination vehicle speed KV _F to shift is performed on the basis of the estimated road surface frictional resistance value μ is calculated from the differential value of the driven wheel speed is determined. The above relationship is such that as the estimated road surface frictional resistance value μ decreases, the shift determination vehicle speed KV _F decreases, and on low-μ roads, the gears are quickly shifted before the engine rotation speed increases to increase the slip of the drive wheels. It is required in advance to prevent it. Then, at step 190, the drive wheel speed V _F
That engine rotational speed is whether a shift decision engine rotational speed equal to or higher than that corresponding to the shift determination vehicle speed KV _F i.e. shift determination vehicle speed KV _F is determined. When the drive wheel speed V _F is but the present routine is terminated. If still less than shift determination vehicle speed KV _F, the driving wheel speed V _F is determined to have reached the shift determination vehicle speed KV _F, in step 200
The SHIFT permission signal is turned on.

That is, by executing the routine of FIG. 3 in the TRCECU 36, when the TRC control is not being performed, the contents of the TRC signal output to indicate that the TRC control is being performed are turned off and the SHIFT permission signal is turned on. Then, the normal shift control is executed by the ECTECU 46. But TRC
Between the start or shift implementation control up and the vehicle speed the slip decreases the driving wheel 18 exceeds a predetermined value KV _F is continued shift prohibiting request, so shifting by ECTECU46 is not executed.

FIG. 5 shows a shift control routine in the ECTECU 46. In the figure, in step 400, the actual vehicle speed V and the throttle valve opening θ are obtained from a shift diagram stored in advance.
, The target shift position (target gear position) g is determined. The throttle valve opening θ is determined by a throttle opening selection routine shown in FIG. That is, in step 600 of FIG.
Opening theta _M of the first throttle valve 24 is whether less than the opening degree theta _S of the second throttle valve 28 is determined, if it is determined to be smaller, the first throttle valve in the register TA in step 610 While opening theta _M of 24 is stored, if it is determined to be larger, the register TA in step 620
Opening theta _S of the second throttle valve 28 is stored in. That is, the throttle valve opening of the smaller of the opening theta _S of the first throttle valve 24 opening theta _M and the second throttle valve 28 is selected. Then, in step 630, the content of the register TA is converted into a communication code signal, and in step 640, the communication code signal is output from EFICU 34 to ECTECU 46. Thus, as throttle opening theta used when the target gear g is determined in step 400 of ECTECU46, the out opening theta _s first throttle valve 24 opening theta _M and the second throttle valve 28 The smaller throttle valve opening is used.

Returning to FIG. 5, at step 410, it is determined whether or not the TRC signal supplied from the TRCECU 36 is in the OFF state, in other words, TRCE
It is determined whether or not the acceleration slip control of CU36 is being performed.
When it is determined that the acceleration slip control is not being performed, normal shift control is performed. That is first determined whether the target shift position g _t is equal to the actual shift position g is at step 430, if it is determined that they match, but the routine is terminated, it does not match If it is determined that there is an upshift in step 440. If it is determined that the upshift is a shift-up control at step 450 is executed, by downshifting control is performed in step 460 if it is determined that the shift-down, and the actual shift position g and the target shift position g _t Matched. In this case, even if there is a difference between the target shift position g _t and the actual shift position g by two gears or more, the actual shift position g is directly made to coincide with the target shift position g _t .

However, when it is determined in step 410 that the acceleration slip control of the TRCECU 36 is being performed, it is determined in step 420 whether or not the content of the SHIFT permission signal from the TRCECU 36 is ON. If it is determined in step 420 that the content of the SHIFT permission signal is not ON, the routine is terminated because the shift is prohibited, and if the content of the SHIFT permission signal is determined to be ON, Since the shift is permitted, the shift of one gear is executed. That is, it is determined whether or not the target shift position g _t is equal to the actual shift position g in step 470, if it is determined that they match, but the routine is terminated, if not coincident If it is determined, it is determined in step 480 whether or not an upshift is performed. If it is determined that the shift is up,
After being updated one step higher than the content actual shift position g of the target shift position g _t (g + 1) at 490, the actual shift position g and the target shift position g _t (= g + 1) in step 500 Upshift control is performed so as to match. However, if it is determined not to be shifted up in step 480, than the target shift position g _t content the actual shift position g in step 510 1
After being updated to the lower position (g-1), the shift down control is executed in step 520 so that the target shift position g _t (= g-1) matches the actual shift position g. In this case, the target shift position g _t and the actual shift position g
Thus, even if there is a difference of two gears or more, only one gear is changed in one control cycle.

In a state where the above operations are repeatedly executed,
In CU46, TRC control is being performed and the SHIFT permission signal is
In the ON state, the change of the gear position of the stepped transmission 14 is limited to one gear at a time by executing steps 470 to 520 corresponding to the gear change width limiting means. Does not occur. Therefore, during the TRC control, a sudden change in the driving force due to a change in the gear ratio does not occur, so that an increase in the slip of the drive wheels 18 associated with the shift of the stepped transmission 14 is prevented. For example, when the traction control is started during the start acceleration in the first speed, when it is shift determination based on the opening theta _s of the second throttle valve 28 is towards the opening is small in ECTECU46, driving force Is determined to be large because the opening degree θ _s is extremely small in order to control the vehicle _speed . In the present embodiment, however, the upshift is determined based on the actual vehicle shift position and the estimated road surface frictional resistance value μ. with shift determination vehicle speed KV _F is determined, the driving wheel speed V _F reaches a shift decision vehicle speed KV _F, 1 single speed width of the step-variable transmission 14 is permitted is limited to one gear. For this reason, since the single shift width of the stepped transmission 14 is limited to one gear position, there is no significant change in the driving force due to a change in the gear ratio, and the stepped transmission during the traction control is not greatly changed. The spread of the slip of the drive wheel 18 associated with the shift of 14 is prevented. Also, a shift determination vehicle speed KV used when permitting the shift of the stepped transmission 14
_F is the actual shift position of the vehicle and the estimated road surface frictional resistance μ
From being determined based on the bets, by the small road having a road surface frictional resistance is determined to be a value shift determination vehicle speed KV _F is small, the drive performs quickly shift before the engine rotational speed increases wheel 18 On the road surface where the road surface friction resistance is not so small, while maintaining the acceleration performance of the vehicle, the shift determination vehicle speed KV _F is determined to be a large value compared to the road surface where the road surface friction resistance is small. Can be.

FIG. 7 is a time chart in the control operation of the above embodiment. In the figure, a slip occurs in the drive wheel 18 during traveling in the first gear, and the TRC control is started to suppress the slip, so that the throttle opening θ _S of the second throttle valve 28 is closed. Has been
Since the change of one gear stage is suppressed to the first speed by the control of ECTECU 46, there is no sudden change in the gear ratio of the stepped transmission 14,
Slip amount appearing on the difference between the driving wheel speed V _F and the driven wheel speed is relatively small also the time width is short. In addition, since the change ratio of the speed ratio at one time is small, insufficient driving force does not occur so much.

On the other hand, in the conventional device, as shown in FIG. 8, during the TRC control period during traveling in the first gear,
Since at once it is shifted up to the third speed position and subsequent to fourth gear, the gear ratio of the stepped transmission 14 is rapidly reduced, and the driving wheel speed V _F and the follower wheel speed at that time As shown in the difference, the slip occurred relatively large and the time width was long. In addition, there is a disadvantage that the driving force becomes insufficient due to the rapid decrease of the gear ratio.

As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

In the above-described embodiment, the EFICU 34, TRCECU 36, and ECTECU 46 are each configured by an independent computer, but may be integrally configured by a common microcomputer.

The above is merely an example of the present invention, and the present invention can be variously modified without departing from the spirit thereof.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining the functions of the control device of the embodiment shown in FIG. FIG. 2 is a block diagram showing the configuration of one embodiment of the present invention. FIG. 3 is a flowchart for explaining the main part of the operation of TRCECU in the embodiment of FIG. FIG. 4 is a flowchart for explaining the operation of the interrupt routine executed in the TRCECU. FIG. 5 is a flowchart for explaining the main part of the operation of the ECTECU in the embodiment of FIG. FIG. 6 is a flowchart for explaining the main part of the operation of EFICU in the embodiment of FIG. FIG. 7 is a time chart for explaining the operation of the embodiment of FIG. FIG. 8 is a time chart for explaining the operation of the conventional apparatus. FIG. 9 is a diagram corresponding to the claims of the present invention. 34: EFIECU 36: TRCECU (traction control device) 46: ECTECU (shift control means) Steps 470 to 520: shift width limiting means

Claims (1)

(57) [Claims] In a vehicle provided with a traction control device for suppressing a driving force so as to prevent the slipping when a driving wheel slips when accelerated by an acceleration operating member, the shift control means An automatic transmission control device that automatically switches a gear position of an automatic transmission in relation to a traveling state of the vehicle, a road surface μ estimation calculating unit that calculates an estimated road surface frictional resistance value, and an actual vehicle shift position. Shift determination vehicle speed determination means for determining a shift determination vehicle speed based on the estimated road surface frictional resistance value calculated by the road surface μ estimation calculation means, and the actual vehicle speed of the vehicle during the driving force suppression by the traction control device is When the vehicle reaches the shift determination vehicle speed determined by the shift determination vehicle speed determining means, a shift width limited hand that permits and limits one shift width of the automatic transmission to one gear position. An automatic transmission control device for a vehicle, comprising: a step; and a traction control device.