JP3684977B2 - Vehicle driving force control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of vehicle driving force control devices.
[0002]
[Prior art]
Conventionally, as a vehicle driving force control device, for example, a device described in JP-A-9-4484 is known.
[0003]
This conventional publication describes a technique for detecting the driver's acceleration intention based on the accelerator opening and the accelerator opening and the engine speed, and changing the TCS control start threshold according to the detected acceleration intention. Has been.
[0004]
Therefore, using this conventional technique, the TCS control start threshold is changed according to the accelerator opening in order to prevent TCS early operation at the time of starting at low speed gear or traveling, that is, as the accelerator opening is larger. It is conceivable to secure the driving force by increasing the TCS control start threshold and delaying the start of the TCS control.
[0005]
[Problems to be solved by the invention]
However, in the conventional TCS control start threshold value changing technique according to the accelerator opening, the engine torque is estimated based only on the accelerator opening, so that an appropriate TCS control may be performed depending on the engine speed condition. There is a problem that the start threshold is not reached.
[0006]
That is, as shown in FIG. 9, the engine torque characteristic varies depending not only on the accelerator opening but also on the engine speed. Therefore, when the TCS control start threshold value is changed only by the accelerator opening, the threshold value is not appropriate depending on the engine speed condition. For example, when comparing point A and point B with the same accelerator opening (4/8 opening) but different engine speeds, the threshold is based on the engine torque Te1 generated at the engine speed Ne1 at point A. When the value is determined, a larger engine torque Te2 is generated at the point B, which causes problems such as the start of the TCS control operation being too early.
[0007]
Further, in the case of a vehicle with a control throttle (ETC), since it has a function of switching engine torque characteristics by a switch, the engine torque is not determined only by the accelerator opening and the engine speed, and becomes a more inappropriate TCS control threshold value. There is a case.
[0008]
On the other hand, it is conceivable to change the TCS control start threshold value by the estimated engine torque or the actual engine torque determined by the accelerator opening and the engine speed.
[0009]
However, in the case of actual engine torque, there is a delay with respect to the target engine torque (delayed by the response of the air system). In the case of the estimated engine torque, as shown in FIG. 5, there is a delay with respect to the target engine torque and the accuracy is poor (difference in atmospheric pressure, difference in fuel, etc.). That is, when used as input information for measures against TCS early operation, there is a problem that the TCS control start threshold change responsiveness is inferior.
[0010]
The problem to be solved by the present invention is to provide a vehicle driving force control device capable of preventing TCS early operation at an appropriate and responsive TCS operation start timing.
[0011]
[Means for Solving the Problems]
In the invention according to claim 1 of the present invention, drive slip calculating means for calculating a value indicating the slip condition of the drive wheel,
TCS control start threshold value setting means for setting a TCS control start threshold value for starting drive force reduction control;
Driving force control means for outputting a command to start driving force reduction control when the driving slip calculation value is equal to or greater than a TCS control start threshold;
In a vehicle driving force control device comprising:
A target engine torque characteristic for the accelerator opening is set in advance, a target engine torque calculating means for calculating a target engine torque determined by the accelerator opening detected value from the accelerator opening detecting means and the target engine torque characteristic ;
TCS control start threshold value correction means for performing correction to increase the set TCS control start threshold value as the target engine torque calculated by the target engine torque calculation means increases is provided.
[0012]
According to a second aspect of the present invention, in the vehicle driving force control device according to the first aspect,
The TCS control start threshold value correction means obtains the target drive wheel torque in consideration of the transmission gear ratio and the final reduction gear ratio with respect to the target engine torque, and the TCS control start threshold set as the target drive wheel torque increases. It is characterized by a means for performing correction to increase the value.
[0013]
According to a third aspect of the present invention, in the vehicle driving force control device according to the first aspect,
The TCS control start threshold value correction means obtains the target drive wheel torque in consideration of the transmission gear ratio, the final reduction gear ratio, and the torque converter characteristics with respect to the target engine torque, and is set as the target drive wheel torque increases. The present invention is characterized in that it is a means for performing correction to increase the control start threshold value.
[0014]
According to a fourth aspect of the present invention, in the vehicle driving force control device according to the first to third aspects,
[0015]
The target engine torque calculation means is a means included in a control throttle logic of a vehicle with a control throttle.
[0016]
Operation and effect of the invention
In the first aspect of the present invention, the driving slip calculation means calculates a value indicating the slip condition of the driving wheel, and the TCS control start threshold setting means starts driving force reduction control. The TCS control start threshold to be set is set, and when the driving slip calculation value becomes equal to or greater than the TCS control start threshold in the driving force control means, a command to start driving force reduction control is output.
During this driving force control, a target engine torque characteristic for the accelerator opening is set in advance in the target engine torque calculation means, and the target engine torque determined by the accelerator opening detection value from the accelerator opening detection means and the target engine torque characteristics. In the TCS control start threshold value correcting means, the TCS control start threshold value that is set is increased as the target engine torque calculated by the target engine torque calculating means is larger.
Thus, since the TCS control start threshold value is corrected by the target engine torque determined by the accelerator opening, it is more appropriate than the case where the threshold value is changed according to the accelerator opening, and the estimated engine torque or The TCS early operation can be prevented by the TCS operation start timing which is more responsive than when the threshold value is changed according to the actual engine torque.
[0017]
In the invention according to claim 2 of the present invention, the TCS control start threshold value correction means obtains the target drive wheel torque in consideration of the transmission gear ratio and the final reduction gear ratio as the target engine torque, The correction is performed to increase the set TCS control start threshold value as the target drive wheel torque is increased.
Therefore, the TCS control start threshold value is corrected according to the target drive wheel torque that dominates the drive wheel slip. Therefore, especially in the manual transmission vehicle, the high speed gear ratio is selected even if the low speed gear ratio is selected. However, TCS early operation can be prevented by appropriate TCS operation start timing.
[0018]
In the third aspect of the present invention, in the TCS control start threshold value correction means, the target drive wheel torque is determined by considering the transmission gear ratio, the final reduction gear ratio, and the torque converter characteristics in the target engine torque. The correction is performed so that the set TCS control start threshold value is increased as the calculated target drive wheel torque is increased.
Therefore, the TCS control start threshold value is corrected in accordance with the target drive wheel torque that controls the drive wheel slip. Therefore, especially in an automatic transmission vehicle, an appropriate TCS operation start timing is used regardless of the torque converter state and the gear position. TCS early operation can be prevented.
[0019]
According to the fourth aspect of the present invention, the target engine torque is calculated by the target engine torque calculating means included in the control throttle logic of the vehicle with the control throttle.
Therefore, it is not necessary to newly add a target engine torque calculation means, and it is possible to prevent TCS early operation at an appropriate TCS operation start timing in response to switching of target engine torque characteristics by a switch.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
The first embodiment is a vehicle driving force control device corresponding to the first and fourth aspects of the invention.
[0021]
First, the configuration will be described.
FIG. 1 is a conceptual diagram showing the main part of the vehicle driving force control apparatus according to Embodiment 1, where a is a driving slip calculation means, b is a TCS control start threshold setting means, c is a driving force control means, and d is Accelerator opening degree detection means, e is target engine torque calculation means, f is TCS control start threshold value correction means, and TCS control start threshold value correction means f has a large target engine torque determined by the accelerator opening degree detection value. Correction is performed to increase the TCS control start threshold that is set so much that early operation of TCS in the low-speed gear can be prevented.
[0022]
FIG. 2 is an overall system diagram showing the vehicle driving force control apparatus according to the first embodiment. 1 is an engine, 2 is an intake passage, 3 is an accelerator pedal, 4 is a throttle valve, 5 is an accelerator opening sensor, and 6A is left. Front wheel speed sensor, 6B is front right wheel speed sensor, 7A is rear left wheel speed sensor, 7B is rear right wheel speed sensor, 8 is engine speed sensor, 9 is ETC / TCS control unit, 10 is throttle actuator, 11 is characteristic It is a changeover switch.
[0023]
The throttle valve 4 is a valve that is controlled to be opened and closed by a throttle actuator 10 in accordance with an accelerator opening that is a depression amount of the accelerator pedal 3, and is disposed in the intake passage 2 of the engine 1.
[0024]
The ETC / TCS control unit 9 inputs signals from the accelerator opening sensor 5, the front wheel speed sensors 6A and 6B, the rear wheel speed sensors 7A and 7B, the engine speed sensor 8, and the characteristic changeover switch 11, and the TCS is not activated. Sometimes, a control command for setting the throttle opening to obtain a target engine torque corresponding to the accelerator opening is output to the throttle actuator 10, and a control command for setting the throttle opening for suppressing the drive wheel slip is output to the throttle actuator 10 during TCS operation. Control is performed.
[0025]
FIG. 3 is a control block diagram showing control throttle logic and TCS logic centered on the ETC / TCS control unit 9.
[0026]
The control throttle logic of the ETC / TCS control unit 9 includes a target engine torque for calculating a target engine torque TRQDRO according to the accelerator opening degree ACC from the accelerator opening degree sensor 5, the vehicle speed VFF, and the selection characteristic from the characteristic changeover switch 11. A calculation unit 20, an air amount calculation unit 21 for calculating a target air amount (target intake air amount) based on the target engine torque TRQDRO and the engine speed NE from the engine speed sensor 8, the target air amount and the engine speed And a throttle opening degree calculation unit 22 for calculating a target throttle opening degree based on NE. The vehicle speed VFF is calculated from the average value of the left and right front wheel speeds.
[0027]
The TCS logic of the ETC / TCS control unit 9 includes a TCS control reference threshold value calculation unit 30 that calculates a TCS control reference threshold value VRRSO according to the vehicle speed VFF, and a TCS control threshold value according to the target engine torque TRQDRO. TCS control threshold value correction value calculation unit 31 for calculating value correction value SLPAC, and addition for calculating TCS control threshold value VRRST by adding TCS control reference threshold value VRRRSO and TCS control threshold value correction value SLPAC 32, a driving wheel speed calculation unit 33 that calculates the driving wheel speed VRR based on the average value of the left and right rear wheel speeds, and a comparator 34 that compares the TCS control threshold value VRRST and the driving wheel speed VRR. .
[0028]
Next, the operation will be described.
[0029]
[TCS logic operation]
[0030]
FIG. 4 is a flowchart showing a flow of TCS logic operation of the ETC / TCS control unit 9, and each step will be described below.
[0031]
In step 40, the target engine torque TRQDRO is read from the control throttle logic. This target engine torque TRQDRO is determined by the magnitude of the accelerator opening ACC at that time so that the target engine torque characteristic as shown by the solid line in FIG. 5 is obtained.
[0032]
In step 41, the TCS control threshold value correction value calculation unit 31 calculates the TCS control threshold value correction value SLPAC according to the target engine torque TRQDRO. That is, as shown in FIG. 6B, the TCS control threshold correction value SLPAC is calculated by the following equation using the target engine torque TRQDRO, the gain K, and the offset value OFFSETAC.
SLPAC = K × TRQDRO + OFFSETAC
[0033]
In step 42, the adder 32 calculates the TCS control threshold value VRRST by the following equation that adds the TCS control reference threshold value VRRSO and the TCS control threshold value correction value SLPAC.
VRRST = VRRSO + SLPAC
The TCS control reference threshold value VRRSO is calculated by the TCS control reference threshold value calculation unit 30 according to the vehicle speed VFF, as shown in FIG.
[0034]
In step 43, the comparator 34 determines whether or not the driving wheel speed VRR is larger than the TCS control threshold value VRRST.
[0035]
In step 44, if VRR> VRRST is determined in step 43, the TCS flag FTCS is set to FTCS = 1.
[0036]
In step 45, TCS control for suppressing drive wheel slip is started based on the setting of the TCS flag.
[0037]
[TCS control]
[0038]
In the TCS control, the driving wheel speed calculating unit 33 corresponding to the driving slip calculating means calculates the driving wheel speed VRR based on the average value of the left and right rear wheel speeds, and the adder 32 corresponding to the TCS control start threshold setting means. The TCS control threshold value VRRST is calculated, and the TCS flag for starting the driving force reduction control is set in the comparator 34 corresponding to the driving force control means when the driving wheel speed VRR becomes larger than the TCS control threshold value VRRST. The
[0039]
During the TCS control, the target engine torque calculation unit 20 calculates the target engine torque TRQDRO determined by the accelerator opening detection value from the accelerator opening sensor 5, and the TCS control start threshold correction value calculation unit 31 calculates the target engine. The TCS control threshold value VRRST is calculated by correction for increasing the TCS control reference threshold value VRRSO as the torque TRQDRO increases, that is, by adding the TCS control reference threshold value VRRSO and the TCS control threshold value correction value SLPAC.
[0040]
As described above, since the TCS control threshold value VRRST is corrected by the target engine torque TRQDRO determined by the accelerator opening degree ACC, it is more suitable than the case where the threshold value is changed according to the accelerator opening degree, and the estimated engine The TCS early operation can be prevented by the TCS operation start timing which is more responsive than when the threshold value is changed according to the torque or the actual engine torque.
[0041]
Next, the effect will be described.
[0042]
(1) A target engine torque calculation unit 20 that calculates a target engine torque TRQDRO determined by an accelerator opening detection value from the accelerator opening sensor 5, and a correction that increases the TCS control reference threshold VRRSO as the target engine torque TRQDRO increases. Since the TCS control threshold value correction value calculation unit 31 that performs the TCS operation is provided, the TCS early operation can be prevented by the appropriate and responsive TCS operation start timing.
[0043]
(2) Since the target engine torque calculation unit 20 is a means included in the control throttle logic of a vehicle with a control throttle, it is not necessary to newly add a target engine torque calculation unit, and the target engine by the characteristic changeover switch 11 Corresponding to the switching of the torque characteristics, TCS early operation can be prevented by appropriate TCS operation start timing.
[0044]
(Embodiment 2)
The second embodiment is a vehicle driving force control apparatus corresponding to the inventions of claims 2 and 4.
[0045]
FIG. 7 is a control block diagram showing control throttle logic and TCS logic centered on the ETC / TCS control unit 9 of the second embodiment.
[0046]
The difference from the control block diagram shown in FIG. 3 is that a multiplier 35 for obtaining the target drive wheel torque in consideration of the transmission gear ratio T / M and the final reduction gear ratio F / D is added to the target engine torque TRQDRO. The TCS control threshold value correction value calculation unit 31 also performs correction to increase the TCS reference control threshold value VRRSO as the target drive wheel torque increases.
[0047]
In the second embodiment, as described above, the TCS control threshold value correction value calculation unit 31 is obtained in consideration of the transmission gear ratio T / M and the final reduction gear ratio F / D in the target engine torque TRQDRO. The means for correcting the TCS reference control threshold value VRRSO to increase as the target drive wheel torque increases, that is, the means for correcting the TCS reference control threshold value VRRSO in accordance with the target drive wheel torque governing the drive wheel slip. In particular, in a manual transmission vehicle, it is possible to prevent TCS early operation at an appropriate TCS operation start timing regardless of whether a low speed gear ratio or a high speed gear ratio is selected.
[0048]
(Embodiment 3)
The third embodiment is a vehicle driving force control device corresponding to the third and fourth aspects of the invention.
[0049]
FIG. 8 is a control block diagram showing control throttle logic and TCS logic centering on the ETC / TCS control unit 9 of the third embodiment.
[0050]
The control block diagram shown in FIG. 3 is different from the control block diagram shown in FIG. 3 in that the target engine torque TRQDRO takes into account the transmission gear ratio T / M, final reduction gear ratio F / D, and torque converter gain (torque gain based on torque converter characteristics). The multipliers 35 and 36 for determining the wheel torque are added. The TCS control threshold value correction value calculation unit 31 also performs correction to increase the TCS reference control threshold value VRRSO as the target drive wheel torque increases. Yes.
[0051]
In the third embodiment, as described above, the TCS control threshold value correction value calculation unit 31 takes into account the transmission gear ratio T / M, the final reduction gear ratio F / D, and the torque gain factor in the target engine torque TRQDRO. Means for correcting the TCS reference control threshold value VRRSO to be larger as the target drive wheel torque obtained in this way is larger, that is, the TCS reference control threshold value VRRSO is corrected according to the target drive wheel torque governing the drive wheel slip. Because of the means, particularly in an automatic transmission vehicle, early TCS operation can be prevented at an appropriate TCS operation start timing regardless of the torque converter state and the shift speed.
[0052]
(Other embodiments)
Although the present invention has been described with reference to the first to third embodiments, the specific configuration is not limited to this, and at least the configuration of the vehicle driving force control device shown in FIG. 1 is provided. As long as various changes and additions are made, they are included in the invention described in claim 1.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a main part of a vehicle driving force control apparatus according to the present invention.
FIG. 2 is an overall system diagram showing the vehicle driving force control apparatus according to the first embodiment;
FIG. 3 is a control block diagram showing control throttle logic and TCS logic centering on the ETC / TCS control unit of the first embodiment.
FIG. 4 is a flowchart showing a TCS logic operation performed by the ETC / TCS control unit according to the first embodiment.
FIG. 5 is a diagram showing responsiveness between target engine torque and estimated engine torque.
FIG. 6 is a reference threshold characteristic diagram with respect to vehicle speed and a correction value characteristic diagram with respect to target engine torque in the first embodiment.
FIG. 7 is a control block diagram showing control throttle logic and TCS logic centering on the ETC / TCS control unit of the second embodiment.
FIG. 8 is a control block diagram showing control throttle logic and TCS logic centering on the ETC / TCS control unit of the third embodiment.
FIG. 9 is an engine torque characteristic diagram showing an engine torque difference depending on an engine speed when a TCS control start threshold is changed according to a conventional accelerator opening.
[Explanation of symbols]
a driving slip calculation means b TCS control start threshold setting means c driving force control means d accelerator opening detection means e target engine torque calculation means f TCS control start threshold correction means

Claims (4)

Drive slip calculating means for calculating a value indicating the slip condition of the drive wheel;
TCS control start threshold value setting means for setting a TCS control start threshold value for starting drive force reduction control;
Driving force control means for outputting a command to start driving force reduction control when the driving slip calculation value is equal to or greater than a TCS control start threshold;
In a vehicle driving force control device comprising:
A target engine torque characteristic for the accelerator opening is set in advance, a target engine torque calculating means for calculating a target engine torque determined by the accelerator opening detected value from the accelerator opening detecting means and the target engine torque characteristic ;
TCS control start threshold value correction means is provided for performing correction to increase the set TCS control start threshold value as the target engine torque calculated by the target engine torque calculation means increases. Driving force control device. The vehicle driving force control device according to claim 1,
The TCS control start threshold value correction means obtains the target drive wheel torque in consideration of the transmission gear ratio and the final reduction gear ratio with respect to the target engine torque, and the TCS control start threshold set as the target drive wheel torque increases. A vehicular driving force control device characterized in that it is a means for performing correction to increase the value. The vehicle driving force control device according to claim 1,
The TCS control start threshold value correction means obtains the target drive wheel torque in consideration of the transmission gear ratio, the final reduction gear ratio, and the torque converter characteristics with respect to the target engine torque, and is set as the target drive wheel torque increases. A vehicular driving force control device characterized in that it is a means for correcting to increase the control start threshold value. The vehicle driving force control device according to claim 1, wherein:
The vehicle driving force control apparatus according to claim 1, wherein the target engine torque calculation means is a means included in a control throttle logic of a vehicle with a control throttle.

Images