JP3661759B2 - Coordinated control device for traction control and automatic transmission control - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to traction control and automatic that are applied to a vehicle in which both a traction control device (abbreviated as TCS) for suppressing drive wheel slip and an automatic transmission control device that performs stepped or continuously variable transmission are mounted. It belongs to the technical field of cooperative control devices with shift control.
[0002]
[Prior art]
Conventionally, as a cooperative control device for traction control and automatic shift control, for example, a device described in JP-A-9-287489 is known.
[0003]
In this publication, the driving force control of a vehicle equipped with an automatic transmission is intended to suppress an increase in shift shock while being stably performed regardless of the throttle opening degree. Shift control is performed to switch from the normal mode shift schedule to the TCS mode shift schedule. The TCS mode shift schedule is faster than the normal mode in the low throttle opening range, and the engine speed is predetermined by downshift. A technique is described in which the shift line is set to be equal to or greater than the value and the shift line is set on the low speed side in the high throttle opening range compared to the normal mode.
[0004]
[Problems to be solved by the invention]
However, in the conventional cooperative control device of traction control and automatic shift control, the TCS command signal for suppressing the driving force and the shift command signal for selecting the TCS shift schedule are output at the same time. There is a problem that the shift is delayed with respect to the operation, and the engine stall cannot be surely avoided.
[0005]
That is, while the TCS side suppresses the driving force with good response first by fuel cut or the like, the shift control side has a delay of at least the shift required time from the command output until the actual downshift is completed. Due to this delay, even if two command signals are output at the same time, the TCS control operates with good response, so that the engine speed decreases significantly due to the TCS control before the engine speed increases due to the downshift. May lead to. In particular, when driving wheel slip occurs even when the engine speed is low, such as when traveling on a low μ road, the possibility of engine stall is increased.
[0006]
A specific example will be described. When starting a vehicle on a slippery road surface such as a snowy road or a muddy road, snow that prevents the drive wheels from slipping to reduce acceleration performance or to prevent the vehicle from moving forward. 2. Description of the Related Art As a shift control device for an automatic transmission having a mode, there is known a device for starting a second speed by prohibiting a shift to the first speed of the automatic transmission when a snow mode is selected by a driver's switch operation. (For example, see JP-A-3-362).
[0007]
When the snow mode is selected as described above, the vehicle can be started by the second speed start, which has a lower torque than the first speed start, so that it is possible to normally prevent the drive wheels from slipping. However, if the driver accidentally depresses the accelerator pedal by a large amount, the torque transmitted to the drive wheels will increase even if the vehicle starts at the second speed, and the drive wheels may slip. .
[0008]
In order to prevent such slipping, a method of combining with a traction control system (TCS) that reduces engine torque by fuel cut, throttle valve closing control, ignition timing retard control, or the like can be considered.
[0009]
However, with this combination, the engine speed when starting at the 2nd speed is lower than when starting at the 1st speed. In this state, when the TCS operates to perform fuel cut or the like and the engine torque is reduced, the engine speed is reduced. In the past, it has been difficult to combine a shift control device for an automatic transmission having a snow mode with a TCS because the possibility of engine stall occurring due to a significant decrease.
[0010]
In addition, when slip occurs in the driving wheel, when the driving force is reduced by operating the TCS, a technique for prohibiting the operation of the TCS or prohibiting an upshift is also known in order to avoid engine stall. It is.
[0011]
However, if the operation of the TCS is prohibited, the TCS operation request cannot be met, the significance of mounting the TCS is lost, and the occurrence of a large drive wheel slip is permitted. In addition, if the upshift is prohibited, it is possible to prevent a decrease in the engine speed due to the upshift, but an increase in the engine speed due to the downshift cannot be expected, and an engine stall may occur due to the operation of the TCS. Remain.
[0012]
The present invention has been made by paying attention to the above-mentioned problems. The object of the present invention is to ensure engine stall due to TCS operation even when driving wheel slip occurs, even when starting at low engine speed or during running. It is another object of the present invention to provide a cooperative control device for traction control and automatic transmission control that achieves suppression of drive wheel slip in response to a TCS operation request.
[0013]
[Means for Solving the Problems]
According to the first aspect of the present invention, the drive wheel slip determination means for determining that the slip equivalent value of the drive wheel connected to the engine via the automatic transmission is greater than or equal to the set threshold value, and the drive wheel slip A traction control device comprising driving force suppression means for starting control to reduce the driving force of the engine based on a traction operation command at the time of determination;
In a vehicle equipped with an automatic transmission control device that controls the transmission ratio of the automatic transmission based on a transmission command,
When starting or running at a speed other than the maximum gear ratio, when the driving wheel slip determining means determines that the driving wheel slips, it first outputs a downshift command to the automatic transmission control device, Waiting for the engine speed to increase due to the progress of the downshift, if the engine speed increases to the engine speed range where there is no possibility of engine stall, Traction operation command to start control to reduce engine driving force Before Coordinate control means for outputting to the driving force suppression means is provided.
[0014]
In the invention according to claim 2 of the present invention, in the cooperative control device for traction control and automatic shift control according to claim 1,
Based on at least one of the vehicle speed and the engine speed at the time when the downshift command is output, the cooperative control means is set to a longer delay time for a higher vehicle speed and a higher engine speed, and the delay set from the downshift command is set. A feature is that the traction operation command is output to the driving force suppressing means after a lapse of time.
[0015]
In the invention according to claim 3 of the present invention, in the cooperative control device for traction control and automatic shift control according to claim 1,
The cooperative control means monitors the engine speed from the time when the downshift command is output, and waits until a second set engine speed is reached at which no engine stall occurs even if the traction control device is activated. It is characterized in that it is a means for outputting a traction operation command when the set engine speed reaches two.
[0016]
Among the present inventions, the invention according to claim 4 provides the following claims. In any one of 3 In the cooperative control device of the described traction control and automatic shift control,
The downshift command output from the cooperative control means to the automatic shift control device is a shift command for forcibly downshifting.
[0017]
In the invention according to claim 5 among the present inventions, claims 1 to In any one of 3 In the cooperative control device of the described traction control and automatic shift control,
As a shift pattern, set a TCS shift pattern that is easy to downshift compared to at least other shift patterns,
The downshift command output from the cooperative control means to the automatic shift control device is a pattern change command for selecting a TCS shift pattern instead of the shift pattern selected at that time.
[0018]
In the invention according to claim 6 among the present inventions, claims 1 to In any one of 5 In the cooperative control device of the described traction control and automatic shift control,
If the engine speed at the time when the drive slip condition is satisfied is in an engine speed range where there is no possibility of engine stall even if the traction control device operates, immediately without performing coordinated control by downshifting It is a means for outputting a traction operation command to the driving force suppressing means.
[0019]
Operation and effect of the invention
The operation and effect of the invention of claim 1 will be described.
[0020]
The basic action of the traction control device is that the driving wheel slip determination means has a slip equivalent value of the driving wheel connected to the engine via the automatic transmission at or above the set threshold value when starting or running when driving wheel slip occurs. If it is determined, the driving force suppression means starts control for reducing the driving force of the engine based on the traction operation command.
[0021]
The basic operation of the automatic transmission control device is that a shift command (for obtaining a target gear ratio suitable for the driving state and driving state of the vehicle when the driving state (for example, vehicle speed) and driving state (for example, throttle opening) of the vehicle changes). The gear ratio of the automatic transmission is controlled based on an upshift command or a downshift command.
[0022]
When starting or running at a speed other than the maximum gear ratio, when the driving wheel slip determination means determines that the driving wheel slips, the cooperative control means first sends a downshift command to the automatic transmission control device. The traction operation command that starts the control to reduce the driving force of the engine is waited until the engine speed rises to the engine speed range where there is no possibility of engine stall due to the progress of downshift, and the driving force is suppressed Output to the means.
[0023]
That is, in the cooperative control, the flow of driving wheel slip determination → downshift command → waiting for engine speed increase → traction operation command, when the drive wheel slip occurs, a downshift command is output prior to the traction operation command, In addition, since an increase in the engine speed is awaited due to the downshift, it is possible to reliably avoid engine stall due to the TCS operation even when starting at low engine speed or during traveling. Further, since the traction operation command is issued immediately when the engine speed increases, suppression of drive wheel slip is achieved in response to the TCS operation request.
[0024]
Therefore, when driving wheel slip occurs, even when starting at low engine speed or during running, engine stall due to TCS operation is reliably avoided, and driving wheel slip suppression is achieved in response to TCS operation requests. be able to.
[0025]
The operation and effect of the invention of claim 2 will be described.
[0026]
In the coordinated control means, the delay time set from the downshift command is set to a longer delay time as the vehicle speed is higher or the engine speed is higher, depending on at least one of the vehicle speed and the engine speed when the downshift command is output. After elapses, a traction operation command is output to the driving force suppressing means.
[0027]
That is, the time required for shifting from the downshift command to the completion of the downshift is longer as the vehicle speed is higher and as the engine speed is higher.
[0028]
Therefore, the delay time from when the downshift command is output to when the traction control operation is started can be set to substantially match the shift required time until the downshift is completed, or slightly less than the shift required time. A short time can be set. That is, it is possible to obtain the start timing of traction control that reliably avoids engine stall by timer management.
[0029]
The operation and effect of the invention of claim 3 will be described.
[0030]
The cooperative control means monitors the engine speed from the time when the downshift command is output, and waits until the second set engine speed at which no engine stall occurs even if the traction control device operates is reached. When the set engine speed is reached, a traction operation command is output.
[0031]
That is, the reason for waiting for traction control is to aim at reliable avoidance of engine stall. On the other hand, I want to start traction control as soon as possible as long as a traction operation request is issued. Therefore, in order to balance these two requirements well, the engine speed is monitored to determine the start time of traction control.
[0032]
Therefore, by monitoring the engine speed, the point in time when the shortest delay time has elapsed from the downshift command can be set as the start timing of the traction control while reliably avoiding the engine stall.
[0033]
The operation and effect of the invention of claim 4 will be described.
[0034]
The downshift command output from the cooperative control means to the automatic shift control device is a shift command for forcibly downshifting.
[0035]
Therefore, when selecting a shift pattern that is easy to downshift, depending on the operating point at that time, the shift may start after the downshift command, but in the case of a forced downshift command, the downshift command is always used. Thus, the shift is started without delay, and the start time of the traction control can be advanced.
[0036]
The operation and effect of the invention of claim 5 will be described.
[0037]
As a shift pattern, a TCS shift pattern that is easy to downshift compared to at least other shift patterns is set, and the downshift command output from the cooperative control means to the automatic shift control device is changed to the currently selected shift pattern. Instead, it is a pattern change command for selecting a TCS shift pattern.
[0038]
Therefore, when the snow mode shift pattern with the fixed 2nd speed is set, if the TCS shift pattern is selected based on the occurrence of the drive wheel slip, the shift pattern is changed so that the downshift from the 2nd speed to the 1st speed is performed. The downshift can be executed by the change.
[0039]
The operation and effect of the invention of claim 6 will be described.
[0040]
If the engine speed at the time when the drive slip condition is satisfied is in an engine speed range where there is no possibility of engine stall even if the traction control device operates, immediately without performing coordinated control by downshifting A traction operation command is output to the traction control device.
[0041]
Therefore, coordinated control by downshift is performed only when it is necessary that an engine stall actually occurs, and at other times, traction control is started immediately, so it is possible to prevent a shift shock due to unnecessary downshift. Therefore, when the engine stall avoidance control is unnecessary, the drive slip can be suppressed with good response.
[0042]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0043]
(Embodiment 1)
First, the configuration will be described.
[0044]
The first embodiment is a cooperative control device for traction control and automatic transmission control corresponding to the inventions of claims 1, 2, and 4, and FIG. 1 shows the traction control and automatic transmission of the first embodiment. 1 is an overall system diagram showing a vehicle to which a cooperative control device with control is applied.
[0045]
The TCS controller 1 (traction control device) is constituted by a microcomputer or the like, and the right front wheel speed VWFR, the left front wheel speed VWFL, the right rear wheel speed VWRR, and the left rear wheel speed from the wheel speed sensors 12FR, 12FL, 12RR, and 12RL, respectively. VWRL and the first throttle opening TVO from the throttle opening sensor 11 are received as input information, and when the drive wheel slip is determined, the ENG controller 5 is requested to control the driving force by cutting the fuel, and the throttle actuator 9 is driven by closing the throttle. A force control request is output.
[0046]
When the ENG controller 5 receives the driving force control request from the TCS controller 1, for example, the fuel supplied for 1/2 cylinder of the engine 4 is cut, and the engine driving force is reduced.
[0047]
The throttle opening sensor 11 detects the first throttle opening TVO of the first throttle valve 8 whose opening is controlled in response to the accelerator pedal 7. The intake pipe provided with the first throttle valve 8 is provided with a second throttle valve 10 in series, and the opening degree of the second throttle valve 10 is controlled by a throttle actuator 9. When the throttle actuator 9 inputs a driving force control request from the TCS controller 1, the second throttle valve 10 is set to a second throttle opening THR smaller than the first throttle opening TVO, and the engine driving force is reduced.
[0048]
The wheel speed sensors 12FR, 12FL, 12RR, and 12RL are sensors that detect the respective wheel speeds of the right front wheel FR and the left front wheel FL, which are driven wheels, and the right rear wheel RR and the left rear wheel RL, which are drive wheels. The wheel speed information based on the right front wheel speed VWFR, the left front wheel speed VWFL, the right rear wheel speed VWRR, and the left rear wheel speed VWRL is information for determining drive wheel slip in the TCS controller 1.
[0049]
The AT controller 2 (automatic shift control device) is constituted by a microcomputer or the like, and includes a first throttle opening TVO from the throttle opening sensor 11, a vehicle speed VSP from the vehicle speed calculation unit 14, and a mode switch signal from the mode switch 13. Is given as input information, and a shift command is output to a shift solenoid (not shown) provided in the control valve unit of the automatic transmission 6.
[0050]
The vehicle speed calculation unit 14 receives the right rear wheel speed VWRR and the left rear wheel speed VWRL from the wheel speed sensors 12RR and 12RL, and calculates the vehicle speed VSP by calculating the average value of both values VWRR and VWRL.
[0051]
The mode change-over switch 13 includes a normal mode shift pattern (see FIG. 5) and a snow mode shift pattern (see FIG. 5) in which regions of the respective shift stages are set by the AT controller 2 using the vehicle speed VSP and the first throttle opening TVO as parameters. 6) is set in advance, and any shift pattern can be selected by the driver's switch operation.
[0052]
The TCS & AT cooperative controller 3 (cooperative control means) is constituted by a microcomputer or the like, and determines the engine speed NE from the engine speed sensor 15, the vehicle speed VSP from the vehicle speed calculation unit 14, and the TCS control start determination from the TCS controller 1. A signal, a gear stage signal from the AT controller 2 and a mode switch signal are provided as input information, and a downshift command is output to the AT controller 2 and a traction operation command is output to the TCS controller 1.
[0053]
Next, the operation will be described.
[0054]
[Cooperative control operation processing]
FIG. 2 is a flowchart showing a flow of cooperative control operation processing of traction and automatic shift performed by the TCS controller 1 and the TCS & AT cooperative controller 3, and each step will be described below.
[0055]
In step 20, the right front wheel speed VWFR, the left front wheel speed VWFL, the right rear wheel speed VWRR, and the left rear wheel speed VWRL are read by the outputs from the wheel speed sensors 12FR, 12FL, 12RR, and 12RL.
[0056]
In step 21, the driven wheel average speed VWF is calculated by the calculation of VWF = (VWFR + VWFL) / 2, and the process proceeds to step 22.
[0057]
In step 22, the driving wheel average speed VWR is calculated by the calculation of VWR = (VWRR + VWRL) / 2, and the process proceeds to step 23.
[0058]
In step 23, the difference between the drive wheel average speed VWR and the driven wheel average speed VWF is calculated as a slip equivalent value of the drive wheel, and it is determined whether this calculated value is equal to or greater than a set threshold value α (drive wheel slip determination). Equivalent to means). Here, the set threshold value α may be given as a fixed value, or may be given as a variable value that increases as the vehicle speed increases according to the vehicle speed VSP.
[0059]
The processing of Step 20 to Step 23 is processing in the TCS controller 1. If YES is determined in Step 23, a TCS control start determination signal is output to the TCS & AT cooperative controller 3, and processing after Step 30 is performed. .
[0060]
In step 30, it is determined whether or not the gear position is the second gear or higher or when the snow mode is selected (second gear) based on the gear signal and the mode switch signal from the AT controller 2. If YES, step 31 is performed. If NO, go to step 35.
[0061]
In step 31, if it is determined in step 30 that the gear position is 2nd or higher, a downshift command (2 → 1 or 3 →→ forcibly lowering the gear position to the gear position lower than the first speed is sent to the AT controller 2. 2) is output, and the process proceeds to Step 32.
[0062]
In step 32, the delay time timer value TM is set to a longer delay time as the vehicle speed VSP is higher and the engine speed NE is higher as a function of the vehicle speed VSP and the engine speed NE. move on.
[0063]
In step 33, the delay time timer value TM is subtracted by 1 every time it is processed in step 33 according to the equation TM = TM−1, and the process proceeds to step 34.
[0064]
In step 34, it is determined whether the delay time timer value TM is TM = 0, that is, whether or not the time by the delay time timer value TM set in step 32 has elapsed. If so, go to Step 35.
[0065]
In step 35, if YES is determined in step 34, a traction operation command is output to the TCS controller 1.
[0066]
Steps 30 to 35 are cooperative control performed by the TCS & AT cooperative controller 3.
[0067]
[Cooperative control action]
First, when the traction control device and the automatic transmission control device are devices that are controlled independently of each other, the basic operation of the traction control device is as follows: If it is determined that the slip equivalent value (VWR-VWF) of the left and right rear wheels RR, RL connected to the engine 4 via the automatic transmission 6 is greater than or equal to the set threshold value α, the engine is based on the traction operation command. Traction control is started to reduce the driving force of the engine by cutting the fuel or closing the second throttle valve 10.
[0068]
On the other hand, the basic operation of the automatic shift control device is to search whether the operating point by the vehicle speed VSP and the first throttle opening TVO crosses the shift line on the shift pattern when the vehicle speed VSP and the first throttle opening TVO change. When the shift line is crossed, the shift stage of the automatic transmission 6 is controlled based on an upshift command or a downshift command for switching from the shift stage before crossing to the shift stage after crossing.
[0069]
Next, in the case of the apparatus according to the first embodiment in which cooperative control of traction and automatic transmission is performed, the cooperative control action described below is performed.
[0070]
First, even if it is determined in step 23 of FIG. 2 that the driving wheel is slipping, if it is determined in step 30 that the gear position is in the first speed state, step 20 → step 21 → step 22 → step 23 → step From 30 to step 35, the traction control for immediately reducing the driving force of the engine is started based on the determination of the driving wheel slip.
[0071]
Then, when it is determined in step 23 of FIG. 2 that the drive wheel is slipping, and in step 30, if it is determined that the gear stage is in the state of 1st speed or more, the process proceeds from step 23 to steps 30 to 35. The flow proceeds and cooperative control is performed.
[0072]
In this coordinated control, first, in step 31, a downshift command for forcibly shifting is output to the AT controller 2, and in steps 32 to 34, the engine rotation in which there is no possibility of engine stall due to the progress of the downshift. The process waits until the engine speed increases to several ranges, and in step 35, a traction operation command for starting control for reducing the driving force of the engine is output to the TCS controller 1.
[0073]
That is, in the cooperative control, the flow is as follows: drive wheel slip determination (step 23) → downshift command (step 31) → wait for engine speed increase (steps 32-34) → traction operation command (step 35).
[0074]
This cooperative control action will be described with reference to the time chart shown in FIG. 3. When the TCS control start determination signal turns from off to on due to the occurrence of drive wheel slip (t1), the 2nd speed starts from the 2nd speed prior to the fuel cut by the traction operation command. A downshift command for shifting to a high speed is output, and a traction control by fuel cut is performed when this delay time (t2−t1) has elapsed (t2) until the downshift is completed just before the shift to the first speed is completed. Is done.
[0075]
Thus, since the start of the traction control is waited for the delay time (t2-t1) from the output of the TCS control start determination signal, the delay time (t2-t1) of this delay time (t2-t1) is shown in FIG. In the meantime, the engine speed increases, and even if the engine speed decreases due to fuel cut, it does not decrease below the engine stall speed, and TCS is activated even when starting or running at low engine speed. The engine stall due to can be surely avoided.
[0076]
Further, when the engine speed increases sufficiently, a traction operation command is immediately issued at the time t2, and fuel cut is performed. Therefore, as shown in the front-rear wheel speed difference characteristic of FIG. Slip suppression is achieved that suppresses drive wheel slip to a set threshold value α or less.
[0077]
In Steps 32 to 34, the vehicle speed VSP and the engine speed NE at the time when the downshift command is output are set to a longer delay time as the vehicle speed is higher and as the engine speed is higher. After the delay time has elapsed, a traction operation command is output to the TCS controller 1.
[0078]
Here, the reason for setting the delay time based on the vehicle speed VSP and the engine speed NE is that the shift required time from the downshift command to the completion of the downshift is longer as the vehicle speed is higher and the engine speed is higher. by.
[0079]
In other words, the delay time is set while estimating the shift required time based on the vehicle speed VSP and the engine speed NE, and the delay time from when the downshift command is output to when the traction control operation starts is reduced by the downshift. It can be set to substantially coincide with the required shift time until completion, or can be set to a time slightly shorter than the required shift time. In the first embodiment, since the engine speed sufficiently increases immediately before the completion of the shift, a time slightly shorter than the required shift time is set as the delay time.
[0080]
Next, the effect will be described.
[0081]
(1) When the TCS & AT coordinating controller 3 is starting or running at a gear stage other than the first speed and it is determined that the drive wheel is slipping, first, a downshift command is output to the AT controller 2, A traction operation command for starting control to reduce the driving force of the engine 4 is output to the TCS controller 1 while waiting for the engine speed to rise to an engine speed range where there is no possibility of engine stall due to the progress of the downshift. Therefore, when drive wheel slip occurs, the engine stall due to TCS operation is surely avoided even when starting or running at low engine speed, and the drive wheel slip is suppressed in response to the TCS operation request. Can be achieved.
[0082]
(2) In the TCS & AT coordinating controller 3, the vehicle speed VSP and the engine speed NE at the time when the downshift command is output are set to the delay time timer value TM for a longer time as the vehicle speed is higher and the engine speed is higher. Since the traction operation command is output to the TCS controller 1 after the time set by the delay time timer value TM set from the shift command has elapsed, the start timing of traction control that reliably avoids engine stall is obtained by timer management. Can do.
[0083]
(3) Since the downshift command output from the TCS & AT cooperative controller 3 to the AT controller 2 is a shift command for forcibly downshifting, when selecting a shift pattern that is easy to downshift, depending on the operating point at that time In some cases, a shift is started after a downshift command, but in the case of a forced downshift command, the shift is always started without a delay from the downshift command, and the start timing of the traction control can be advanced.
[0084]
(Embodiment 2)
The second embodiment is a cooperative control device for traction control and automatic transmission control corresponding to the inventions of claims 3, 5, and 6.
[0085]
Since the configuration is the same as the configuration of the first embodiment shown in FIG. 1, the illustration and description are omitted.
[0086]
Next, the operation will be described.
[0087]
[Cooperative control operation processing]
FIG. 4 is a flowchart showing a flow of cooperative control operation processing of traction and automatic shift performed by the TCS controller 1 and the TCS & AT cooperative controller 3, and each step will be described below.
[0088]
Steps 20 to 23 are the same as steps 20 to 23 shown in FIG.
[0089]
In step 40, the engine speed NE at the time when the drive slip condition in step 23 is satisfied is equal to or lower than the first set engine speed NE1 at which engine stall may occur even if the traction control device operates. If YES, the process proceeds to step 41. If NO, the process proceeds to step 45.
[0090]
In step 41, it is determined based on the gear position signal and the mode switch signal from the AT controller 2 whether or not the gear position is the second speed or higher, or when the snow mode is selected (second speed). If NO, go to step 42.
[0091]
In step 42, the engine speed NE is NE ≦ NE1, and the gear position is the first speed with no room for downshift, and if the traction operation is performed, the possibility of engine stall is high, so the traction operation is prohibited. The
[0092]
In step 43, if it is determined in step 41 that the gear position is 2nd or higher, a downshift command (2 → 1 or 3 →) forcing the AT controller 2 to lower the gear position to the first gear position. 2), and if it is determined in step 41 that the snow mode is selected, a downshift command for switching from the snow mode to the TCS mode shift pattern is output, and the process proceeds to step 44.
[0093]
Here, the AT controller 2 uses the vehicle speed VSP and the first throttle opening TVO as parameters, and, as shown in FIG. As shown in FIG. 6, the snow mode shift pattern in which the first speed use area in the normal mode is the second speed use area, and the area where the first throttle opening TVO is low is higher than the normal mode shift line. In the region where the first throttle opening TVO is high, a shift pattern of the TCS mode having a shift line set to a lower speed side than the normal mode shift line is set in advance. If a shift pattern in the snow mode is selected and a drive wheel slip occurs when the snow mode is selected, the TCS mode It is switched to the mode.
[0094]
In step 44, it is determined whether or not the engine speed NE is equal to or higher than the second set engine speed NE2 at which no engine stall occurs even if the traction control device is operated, and is constant until the condition NE ≧ NE1 is satisfied. The determination is repeated for each cycle, and when the condition of NE ≧ NE1 is satisfied, the process proceeds to step 45.
[0095]
In step 45, if YES is determined in step 34, a traction operation command is output to the TCS controller 1.
[0096]
Steps 40 to 45 are cooperative control performed by the TCS & AT cooperative controller 3.
[0097]
[Cooperative control action]
In step 44 in FIG. 4, the engine speed NE from when the downshift command is output is monitored until the second set engine speed NE2 at which no engine stall occurs even when the traction control device operates is reached. After waiting, when the second set engine speed NE2 is reached, the routine proceeds to step 45 where a traction operation command is output.
[0098]
That is, the reason for waiting for traction control is to aim at reliable avoidance of engine stall. On the other hand, I want to start traction control as soon as possible as long as a traction operation request is issued. Therefore, in order to make these two requirements compatible, the engine speed NE is monitored to determine the start time of the traction control.
[0099]
As a shift pattern, a TCS mode shift pattern that is easy to downshift is set, and the TCS & AT cooperative controller 3 outputs a downshift command to the AT controller 2 in place of the currently selected snow mode shift pattern in the TCS mode. Therefore, a downshift from the second speed to the first speed is performed by the pattern change command.
[0100]
When the engine speed NE at the time when the drive slip condition of step 23 is satisfied is in an engine speed range (NE> NE1) where no engine stall is likely to occur even when the traction control device is activated, step 40 is performed. From step S45, the traction operation command is immediately output to the TCS controller 1 without performing cooperative control by downshifting.
[0101]
Next, the effect will be described.
[0102]
(4) In step 44, the engine speed NE from the time when the downshift command is output is monitored and until the second set engine speed NE2 is reached at which no engine stall occurs even if the traction control device is activated. When the second set engine speed NE2 is reached, the traction operation command is output. Therefore, the point in time when the shortest delay time has elapsed from the downshift command while reliably avoiding engine stall is determined. It can be.
[0103]
(5) A TCS mode shift pattern that is easy to downshift is set as the shift pattern, and the downshift command output from the TCS & AT cooperative controller 3 to the AT controller 2 is changed to the snow mode shift pattern selected at that time. Instead, a pattern change command for selecting a TCS shift pattern is used, so that a downshift can be executed by changing the shift pattern.
[0104]
(6) The engine speed NE at the time when the drive slip condition in step 23 is satisfied is an engine speed range where there is no possibility of engine stall even if the traction control device is operated (NE> NE1). In this case, since the traction operation command is immediately output to the TCS controller 1 without performing the coordinated control by the downshift, the coordinated control by the downshift is performed only when necessary so that the engine stall actually occurs. At this time, since the traction control is started immediately, not only can the shift shock due to unnecessary downshift be prevented, but also the drive slip can be suppressed with good response when the engine stall avoidance control is unnecessary.
[0105]
(Other embodiments)
In the first and second embodiments, the example in which the TCS & AT cooperative controller 3 is provided as an independent controller for the TCS controller 1 and the AT controller 2 has been described. However, a TCS & AT cooperative controller may be added in the TCS controller 1. Further, a TCS & AT cooperative control unit may be added in the AT controller 2.
[0106]
In the first and second embodiments, an example in which a stepped transmission is used as an automatic transmission is shown, but a continuously variable transmission such as a belt type or a toroidal type may be used.
[0107]
In the first embodiment, an example of taking the timing of the TCS operation by the timer management based on the vehicle speed and the engine speed is shown. In the second embodiment, an example of taking the timing of the TCS operation by monitoring the engine speed is shown. It is also possible to measure the speed ratio, which is the ratio of the input / output speed of the transmission, and to take the timing of TCS operation while monitoring the progress of the speed change by measuring the change in the speed ratio, or equivalent to the engine speed. It is also possible to take an example in which the timing of the TCS operation is taken while monitoring the transmission input rotational speed that is a value to be transmitted.
[0108]
In the first and second embodiments, the example in which the shift command is forcibly issued and the example in which the shift pattern is changed are shown as the configuration for downshifting by the downshift command. However, as an example in which the shift line of the shift pattern itself is changed. Also good.
[0109]
In the first and second embodiments, as an example of the slip state for detecting the drive wheel slip, the difference between the front and rear wheel rotational speeds, which is the speed difference between the drive wheel and the driven wheel, is shown. It is good also as an example which detects driving wheel slip using other slip information like this.
[0110]
In the second embodiment, the first engine speed setting value NE1 and the second engine speed setting value NE2 may be given as fixed values, but the TCS torque reduction amount depends on the slip state (for example, driving wheel acceleration). Since they are different, the first engine speed setting value NE1 and the second engine speed setting value NE2 may also be given by variable values that change depending on the slip state. When this variable value is given, optimum engine speed setting values NE1 and NE2 can be obtained regardless of the slip state (or torque down amount).
[Brief description of the drawings]
FIG. 1 is an overall system diagram showing a vehicle to which a cooperative control device for traction control and automatic transmission control according to a first embodiment is applied.
FIG. 2 is a flowchart showing a flow of cooperative control operation processing of traction control and automatic shift control performed by the TCS controller 1 and the TCS & AT cooperative controller 3 of the first embodiment.
FIG. 3 is a time chart showing a cooperative control action between the traction control and the automatic transmission control according to the first embodiment.
FIG. 4 is a flowchart showing a flow of cooperative control operation processing of traction control and automatic shift control performed by the TCS controller 1 and the TCS & AT cooperative controller 3 of the second embodiment.
FIG. 5 is a diagram showing a shift pattern in a normal mode set in the AT controller 2 of the second embodiment.
FIG. 6 is a diagram showing a shift pattern in a snow mode set in the AT controller 2 of the second embodiment.
FIG. 7 is a diagram showing a shift pattern in a TCS mode set in the AT controller 2 of the second embodiment.
[Explanation of symbols]
1 TCS controller (traction control device)
2 AT controller (automatic shift control device)
3 TCS & AT cooperative controller (cooperative control means)
4 engine
5 ENG controller
6 Automatic transmission
7 Accelerator pedal
8 First throttle valve
9 Throttle actuator
10 Second throttle valve
11 Throttle opening sensor
12FR, 12FL, 12RR, 12RL Wheel speed sensor
13 Mode selector switch
14 Vehicle speed calculator
15 Engine speed sensor
FR front right wheel
FL Front left wheel
RR Right rear wheel
RL left rear wheel

Claims (6)

Drive wheel slip determination means for determining that the slip equivalent value of the drive wheel connected to the engine via the automatic transmission is greater than or equal to a set threshold value, and driving the engine based on a traction operation command when determining the drive wheel slip A traction control device comprising driving force suppression means for starting control to reduce force;
In a vehicle equipped with an automatic transmission control device that controls the transmission ratio of the automatic transmission based on a transmission command,
When starting or running at a speed other than the maximum gear ratio, if the driving wheel slip determining means determines that the driving wheel is slipping, first, a downshift command is output to the automatic transmission control device, and the downshift wait for increase in the engine speed due to progress, the engine speed until the engine rotational speed range no possibility that the engine stall will occur rises, before Symbol driving force traction operation command to start the control for reducing the driving force of the engine A cooperative control device for traction control and automatic shift control, characterized in that a cooperative control means for outputting to the suppression means is provided. In the cooperative control device of traction control and automatic transmission control according to claim 1,
Based on at least one of the vehicle speed and the engine speed at the time when the downshift command is output, the cooperative control means is set to a longer delay time for a higher vehicle speed and a higher engine speed, and the delay set from the downshift command is set. A cooperative control device for traction control and automatic transmission control, characterized in that after a lapse of time, the traction operation command is output to the driving force suppression means. In the cooperative control device of traction control and automatic transmission control according to claim 1,
The cooperative control means monitors the engine speed from the time when the downshift command is output, and waits until a second set engine speed is reached at which no engine stall occurs even if the traction control device is activated. 2. A cooperative control device for traction control and automatic transmission control, characterized in that the traction operation command is output when the set engine speed is reached. In the cooperative control device of traction control and automatic shift control according to any one of claims 1 to 3 ,
A cooperative control device for traction control and automatic transmission control, wherein the downshift command output from the cooperative control means to the automatic transmission control device is a transmission command for forcibly downshifting. In the cooperative control device of traction control and automatic shift control according to any one of claims 1 to 3 ,
As a shift pattern, set a TCS shift pattern that is easy to downshift compared to at least other shift patterns,
Traction control and automatic shift characterized in that the downshift command output from the cooperative control means to the automatic shift control device is a pattern change command for selecting a TCS shift pattern instead of the shift pattern currently selected. Coordinated control device with control. In the cooperative control device of traction control and automatic shift control according to any one of claims 1 to 5 ,
If the engine speed at the time when the drive slip condition is satisfied is in an engine speed range where there is no possibility of engine stall even if the traction control device operates, immediately without performing coordinated control by downshifting A cooperative control device for traction control and automatic shift control, characterized in that the traction operation command is output to the driving force suppression means.

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