JP3627448B2 - Vehicle road gradient judgment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sufficient accuracy of road slope determination by the use of vehicular acceleration. SOLUTION: In the case that engine brake is not sensed to be used in the present gear stage of an automatic transmission 14 by means of an engine brake inaction state determination means 110, the determination of road slope by means of a road slope determination means 106 base on vehicular acceleration is prohibited by a road slope determination prohibition means 114. Road slope determination is thus prevented in the case that acceleration does not means road slope, so that accuracy of the road slope determination is kept. At the same time, the deterioration of drivability is properly prevented, which may be caused by executing hill climbing control or downslope control based on road slope determination without accuracy.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle road gradient determination apparatus that determines a gradient of a traveling road surface based on vehicle acceleration.
[0002]
[Prior art]
2. Description of the Related Art A vehicle is known in which the gear stage of an automatic transmission has an engine brake operation state where the engine brake is effective and an engine brake non-operation state where the engine brake is not effective. For example, a vehicle equipped with a gear stage achieved by engagement of a one-way clutch, such as a 5-speed forward automatic transmission described in JP-A-8-246913, or hydraulic friction engagement for engine braking This is a vehicle equipped with a gear stage having an engine brake operation state and a non-operation state by electrically switching the engagement state of the device.
[0003]
By the way, in a vehicle equipped with an automatic transmission, climbing control that restricts the high-speed gear of the automatic transmission to improve power performance on an uphill road, or automatic transmission of an automatic transmission to improve engine braking performance on a downhill road. Downhill control that restricts the high-speed side gear stage may be provided, and road gradient determination that determines road gradient based on vehicle acceleration in order to determine the execution conditions of such uphill control and downhill control, etc. Means may be provided.
[0004]
[Problems to be solved by the invention]
However, as described above, when the road gradient determination means is provided in a vehicle in which the gear stage of the automatic transmission has an engine brake operation state and an engine brake non-operation state, When the engine is not connected to the drive wheels and the engine brake is not working, or during cornering when the driving force is lost due to cornering resistance, Since the vehicle acceleration does not necessarily reflect the road gradient, the accuracy of road gradient determination based on the vehicle acceleration cannot be obtained. In addition, ascending slope control or descending slope control is executed based on road gradient determination with inaccurate accuracy, there is a possibility that drivability may be impaired due to unnecessary restriction of the high-speed gear stage of the automatic transmission. there were.
[0005]
For example, the road gradient determination means uses the relationship between the throttle valve opening, the gear stage, and the rotational acceleration of the automatic transmission output shaft and the vehicle acceleration (that is, the reference acceleration) in flat road traveling, and the actual throttle valve opening If the actual vehicle acceleration is small with respect to the reference acceleration determined from the rotational acceleration of the gear stage and the automatic transmission output shaft, it is determined that the road is uphill, and if it is large, the road is downhill. Then, since the vehicle acceleration does not correspond to the road gradient, the accuracy of the road gradient determination is lowered.
[0006]
The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicular road gradient determination device capable of sufficiently obtaining the accuracy of road gradient determination using vehicle acceleration. .
[0007]
[Means for Solving the Problems]
In order to achieve this object, the gist of the present invention is that the gear stage of the automatic transmission has an engine brake operation state where the engine brake is effective and an engine brake non-operation state where the engine brake is not effective. A vehicle road gradient determination device comprising road gradient determination means for determining a road gradient based on vehicle acceleration, wherein (a) Based on engine brake friction engagement device and solenoid valve operating state indicating one-way clutch operation An engine brake non-operation state determination means for determining that the gear stage is in an engine brake non-operation state; and (b) the engine brake non-operation state determination means determines that the gear stage is in an engine brake non-operation state. If so, road gradient determination prohibiting means for prohibiting road gradient determination based on vehicle acceleration by the road gradient determination means is included.
[0008]
【The invention's effect】
In this way, the engine brake non-operation state determination means Based on engine brake friction engagement device and solenoid valve operating state indicating one-way clutch operation If it is determined that the gear stage is in an engine brake inactive state, the road gradient determination prohibiting unit prohibits the road gradient determination based on the vehicle acceleration by the road gradient determination unit. Accordingly, road gradient determination is prohibited when the vehicle acceleration does not necessarily reflect the road gradient, so that the accuracy of road gradient determination is maintained. At the same time, it is also preferable to prevent the drivability from being impaired by performing the uphill control or the downhill control based on the road gradient determination where accuracy cannot be obtained.
[0009]
Other aspects of the invention
Here, it is preferable that the road gradient determination unit determines whether or not the road gradient reflected in the vehicle acceleration falls below a preset uphill control start gradient based on the vehicle acceleration, or starts the downhill control. Each of the road gradient determination prohibiting means determines whether the actual gear is in an engine brake non-operation state by the engine brake non-operation state determination means. The gradient determination by the gradient determination means is prohibited, or the calculation of the reference acceleration or the actual acceleration is prohibited and the gradient determination is substantially prohibited.
[0010]
Preferably, a turning travel determination means for determining that the vehicle is turning is provided, and the road gradient determination prohibiting means determines that the vehicle is turning by the turning travel determination means. If it is, road gradient determination based on vehicle acceleration by the road gradient determination means is prohibited, and acceleration calculation by the acceleration calculation means is prohibited. In this way, road gradient determination is prohibited during cornering resistance during driving while the driving force is lost, that is, when the vehicle acceleration does not necessarily reflect the road gradient, so the accuracy of road gradient determination is maintained. The In addition, it is preferable that the drivability is impaired by unnecessarily restricting the high-speed gear stage of the automatic transmission by executing the uphill control or the downhill control based on the road gradient determination where accuracy is not obtained. Is prevented.
[0011]
Preferably, a shift determination is made based on the actual engine load and vehicle speed from a preset normal shift shift diagram (basic shift diagram), and the automatic transmission is caused to execute the shift determined. When the road slope is determined to be a preset uphill / downhill control start slope by the road slope judgment means, the high speed side gear of the automatic transmission is limited. Uphill / downhill shift diagram switching means for switching to the uphill / downhill shift diagram is further provided. In such a case, the drivability is impaired because the high-speed gear stage of the automatic transmission is unnecessarily limited by executing the uphill control or the downhill control based on the road gradient determination where accuracy cannot be obtained. Is preferably prevented.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a skeleton diagram showing an example of an automatic transmission for a vehicle that is shift-controlled by a shift control device including a road gradient determination device according to an embodiment of the present invention. In the figure, the output of the engine 10 is input to an automatic transmission 14 via a torque converter 12 and transmitted to drive wheels via a differential gear device and an axle (not shown).
[0014]
The torque converter 12 includes a pump impeller 18 connected to the crankshaft 16 of the engine 10, a turbine impeller 22 connected to the input shaft 20 of the automatic transmission 14, the pump impeller 18 and the turbine impeller 22. And a stator 28 that is prevented from rotating in one direction by a one-way clutch 26.
[0015]
The automatic transmission 14 includes a first transmission 30 that switches between two stages of high and low, and a second transmission 32 that can switch between a reverse gear stage and four forward stages. The first transmission 30 includes an HL planetary gear unit 34 including a planetary gear P0 that is rotatably supported by the sun gear S0, the ring gear R0, and the carrier K0 and meshed with the sun gear S0 and the ring gear R0, and the sun gear S0 and the carrier. A clutch C0 and a one-way clutch F0 provided between K0 and a brake B0 provided between the sun gear S0 and the housing 41 are provided.
[0016]
The second transmission 32 is supported by the sun gear S1, the ring gear R1, and the carrier K1, and a first planetary gear unit 36 including a planetary gear P1 meshed with the sun gear S1 and the ring gear R1, and the sun gear S2. A second planetary gear unit 38 comprising a planetary gear P2 which is rotatably supported by the ring gear R2 and the carrier K2 and meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3 and the carrier K3 is rotatable. And a third planetary gear unit 40 including a planetary gear P3 supported and meshed with the sun gear S3 and the ring gear R3.
[0017]
The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2, and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft. The ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and sun gear S3 and the intermediate shaft 44, and a clutch C2 is provided between the sun gear S1 and sun gear S2 and the intermediate shaft 44. A band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2 is provided in the housing 41. A one-way clutch F1 and a brake B2 are provided in series between the sun gear S1 and sun gear S2 and the housing 41. The one-way clutch F <b> 1 is configured to be engaged when the sun gear S <b> 1 and the sun gear S <b> 2 try to reversely rotate in the direction opposite to the input shaft 20.
[0018]
A brake B3 is provided between the carrier K1 and the housing 41, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 41. The one-way clutch F2 is configured to be engaged when the ring gear R3 attempts to rotate in the reverse direction.
[0019]
In the automatic transmission 14 configured as described above, for example, the first reverse speed and the fifth forward speed are switched according to the operation table shown in FIG. In FIG. 2, ◯ indicates an engaged state, X indicates a non-engaged state, and ◎ indicates that the lockup clutch 24 is operated when it is engaged or slipped. As is apparent from FIG. 2, the drive mechanism is configured so that the engine brake always operates in the fourth speed gear stage and the fifth speed gear stage. In the stage, the solenoid No. of the fourth solenoid valve S4. Engagement of engine brake hydraulic friction engagement device 4 when de-energized 4 (brake B4 at the first gear, clutch C0 at the second gear, brake B1 at the third gear), Alternatively, the engine brake is activated by engagement of a one-way clutch (one-way clutch F2 at the first gear, one-way clutch F0 at the second gear, and one-way clutch F1 at the third gear). Release of hydraulic friction engagement device for engine brake and one-way clutch (one-way clutch F2 at first gear, one-way clutch F0 at second gear, one-way clutch F1 at third gear) When released, the engine brake is ineffective and the engine brake is inactive. That is, the first through third gears correspond to engine brake operation state switching gears that can be switched between the engine brake operation state and the engine brake non-operation state.
[0020]
In the present embodiment, when the shift lever 72 is operated to the D, 4 range, the shift range is from the first speed to the fifth speed gear stage, but the fourth solenoid valve S4 is de-energized. As a result, the engine speed from the first speed to the third speed is made inoperative. When the shift lever 72 is operated to the 3rd range, the fifth speed gear stage is prohibited and the first to third speed gear stages are brought into the engine braking state. When the shift lever 72 is operated to the second range, the fifth speed gear stage and the fourth speed gear stage are prohibited, and the first to third speed gear stages are brought into the engine braking state. When the shift lever 72 is operated to the L range, the fifth speed gear stage to the second speed gear stage are prohibited, and the first speed gear stage is brought into an engine braking state.
[0021]
As shown in FIG. 3, a throttle valve 56 driven by a throttle actuator 54 based on the operation amount of the accelerator pedal 50 detected by the accelerator operation amount sensor 52 is provided in the intake pipe of the engine 10 of the vehicle. . Further, the rotational speed N of the engine 10 _E The engine rotation speed sensor 58 for detecting the intake air amount, the intake air amount sensor 60 for detecting the intake air amount Q / N of the engine 10, and the temperature T of the intake air _A The intake air temperature sensor 62 detects the opening degree θ of the throttle valve 56. _TH The throttle sensor 64 for detecting the rotation speed N of the output shaft 42 _OUT That is, the vehicle speed sensor 66 for detecting the vehicle speed V and the coolant temperature T of the engine 10 _W The coolant temperature sensor 68 detects the brake, the brake switch 70 detects the operation of the brake, and the operation position P of the shift lever 72. _SH Operation position sensor 74 for detecting the rotational speed N of the input shaft 20, that is, the clutch C0 _C0 Oil temperature T of the clutch C0 rotation sensor 75 and the hydraulic control circuit 84 for detecting _OIL An oil temperature sensor 77 for detecting the engine speed is provided. _E , Intake air quantity Q / N, intake air temperature T _A , Throttle valve opening θ _TH , Vehicle speed V, engine coolant temperature T _W , Brake operating state BK, shift lever 72 operating position P _SH , Rotational speed N of clutch C0 _C0 , Hydraulic oil temperature T _OIL Is supplied to the engine electronic control unit 76 or the shift electronic control unit 78.
[0022]
The engine electronic control device 76 is a so-called microcomputer having a CPU, a RAM, a ROM, and an input / output interface, and the CPU processes an input signal in accordance with a program stored in the ROM in advance using a temporary storage function of the RAM. Then, various engine controls are executed. For example, the fuel injection valve 79 is controlled for fuel injection amount control, the igniter 80 is controlled for ignition timing control, a bypass valve (not shown) is controlled for idle speed control, and a throttle actuator is controlled for traction control. The throttle valve 56 is controlled by 54. The engine electronic control unit 76 is connected to the transmission electronic control unit 78 so as to be able to communicate with each other, and a signal necessary for one side is appropriately transmitted from the other side.
[0023]
The shift electronic control unit 78 is also a microcomputer similar to the above, and the CPU processes the input signal in accordance with a program stored in the ROM 79 in advance while using the temporary storage function of the RAM, and each electromagnetic control circuit 84 is controlled. Drives a valve or linear solenoid valve. For example, the shift electronic control unit 78 is configured so that the opening degree θ of the throttle valve 56 is reduced. _TH Throttle pressure P with a size corresponding to _TH The linear solenoid valve SLT for generating the pressure, the linear solenoid valve SLN for controlling the accumulator back pressure, the engagement and release of the lockup clutch 24, the slip amount, the direct control of the brake B3, and the shift of the clutch to clutch. To control the linear solenoid valve SLU. Further, the shift electronic control unit 78 determines the actual throttle valve opening θ from the previously stored shift diagram shown in FIG. _TH When determining the gear stage of the automatic transmission 14 on the basis of the vehicle speed V and driving the solenoid valves S1, S2, and S3 so as to obtain the determined gear stage and engagement state, and generating the engine brake Drives the solenoid valve S4.
[0024]
FIG. 4 is a functional block diagram for explaining a main part of the control function of the shift electronic control device 78. In the figure, the shift control means 100 is an amount indicating the load of the engine 10, for example, a throttle valve opening θ from the previously stored relationship shown in FIG. _TH On the basis of the actual vehicle speed V and the actual gear speed V, the gear stage of the automatic transmission 14 is determined, and the solenoid valves S1, S2, S3 are driven so as to obtain the determined gear stage and engagement state. When the engine brake is generated, the electromagnetic valve S4 is driven.
[0025]
The uphill / downhill control means 102 limits the high speed side gear of the automatic transmission 14 when it is determined that the start condition of the uphill control or the downhill control is satisfied based on the vehicle acceleration, that is, the high speed side gear. By prohibiting the upshift to the gear or moving the shift-up line to the high vehicle speed side to increase the shift point vehicle speed to the high speed gear, the power performance on the uphill road and the engine brake performance on the downhill road are enhanced. In the climbing control, the power-on downshift is a starting condition, and in the descending slope control, the braking operation is a starting condition. Preferably, the ascending / descending slope control means 102 includes an acceleration calculation means 104 for calculating a reference acceleration MOBGBU and an actual vehicle acceleration (actual acceleration) MOGBGBW when the vehicle travels on a flat road with an actual driving force, and this acceleration. Based on the vehicle acceleration calculated by the calculation means 104, whether the road gradient reflected in the vehicle acceleration falls below a preset uphill control start gradient, and whether the downhill control start equivalent gradient is exceeded. When the uphill control start gradient or downhill control start gradient is determined by the road gradient determination means 106 and the road gradient determination means 106, the uphill road is determined from the normal basic shift map shown in FIG. Uphill / downhill shift map to switch to preset uphill / downhill shift map to improve power performance and engine braking performance on downhill road And a switch means 108. In order to limit the high speed gear of the automatic transmission 14, this uphill / downhill shift diagram is, for example, from the normal shift diagram shown in FIG. 4-5 shift line (4 → 5 shift line and 5 → 4 shift line) for shifting with the gear stage, or in addition, 3-for shifting between the third speed gear stage and the fourth speed gear stage. 4 shift lines (3 → 4 shift lines and 4 → 3 shift lines) deleted, or 4-5 shift lines or 4-5 shift lines and 3-4 shift lines or a part or all of them are on the high vehicle speed side A staggered one is used.
[0026]
The acceleration calculation means 104 is used to calculate the engine load, that is, the throttle valve opening θ when traveling on a flat road. _TH , The gear stage G of the automatic transmission 14, and the rotational speed N of the automatic transmission output shaft 42 _OUT And the vehicle acceleration (that is, the reference acceleration) MOBGBU is stored in advance, and the actual throttle valve opening θ is determined from the relationship. _TH , Gear stage G, and rotational speed N of automatic transmission output shaft 42 _OUT And the reference acceleration MOBGBU is calculated based on the rotational acceleration dN of the automatic transmission output shaft 42. _OUT The actual acceleration MOGBGBW is calculated based on / dt. The road gradient determining means 106 determines whether or not the actual vehicle acceleration MOBGBW is equal to or less than a value lower than the reference acceleration MOBGBU by a predetermined value K1, and the actual vehicle acceleration MOBGBW is higher than the reference acceleration MOBGBU by a predetermined value K2. It is determined whether or not the above has been reached. That is, the road gradient determination means 106 determines whether or not the determination formula (MOBGBW ≦ MOBBU-K1) is satisfied and whether or not the determination formula (MOBGBW ≧ MOBBU + K2) is satisfied. (−K1) and (K2) on the right-hand side correspond to the uphill control start gradient and the downhill control start gradient, respectively.
[0027]
The engine brake non-operation state determination means 110 determines whether or not the gear stage of the automatic transmission 14 is in the engine brake non-operation state according to a predetermined determination condition. As described in FIG. 2 above, when the shift lever 72 is in the D range or the 4 range, the fourth speed gear stage and the fifth speed gear stage are always in the engine braking state, but the first speed to the first speed The third speed gear stage can be in either an engine brake operation state or a non-operation state, and in the first to third speed gear stages, the engine brake hydraulic friction engagement device (first Brake B4 at the second gear, clutch C0 at the second gear, brake B1 at the third gear, and one-way clutch (one-way clutches F0 and F2 at the first gear, second gear) Is the one-way clutch F0 at the gear stage and the one-way clutches F0 and F1) at the third speed gear stage disengaged to determine whether the engine brake is inoperative and the engine brake is not in effect? Or is, the engine solenoid valve S1 to S4 or linear solenoid valve SLU showing the operation of the hydraulic friction engagement device and a one-way clutch brake and the like based on the operating state of the SLN, is determined.
[0028]
The turning determination unit 112 determines that the vehicle is turning based on, for example, a signal from a steering angle sensor or a lateral acceleration sensor (not shown). The road gradient determination prohibiting unit 114 prohibits the road gradient determination unit 106 from determining the road gradient based on the vehicle acceleration when the turning determination unit 112 determines that the vehicle is turning, and calculates the acceleration. Calculation of acceleration by means 104 is prohibited. Even when the calculation of the acceleration is prohibited, the gradient determination by the road gradient determination means 106 becomes impossible, so that the gradient determination is substantially prohibited.
[0029]
FIG. 6 and FIG. 7 are flowcharts for explaining a main part of the control operation of the shift electronic control device 78. FIG. 6 shows a gradient determination prohibiting control routine, and FIG. 7 shows an uphill / downhill control routine.
[0030]
In FIG. 6, in step (hereinafter, step is omitted) SA <b> 1, it is determined whether or not the shift lever 72 is operated to the D range or the 4 range which is the high speed side forward travel range. If the determination at SA1 is negative, this routine is terminated. If the determination is positive, at SA2, the actual gear stage of the automatic transmission 14 can be switched between the engine brake operation state and the non-operation state. In this embodiment, it is determined whether or not the operation state switching gear stage is set, for example, whether or not it is the third speed gear stage based on a shift output signal.
[0031]
If the determination in SA2 is negative, SA4 is executed. If the determination is positive, in SA3 corresponding to the engine brake non-operation state determination means 110, the engine brake operation state switching gear is set in the engine brake state. The engine brake is activated by engaging the gear in a gear train, that is, a power transmission path constituted by the one-way clutch that achieves the gear stage. The determination is made based on whether or not the one-way clutch that can be in the engaged state is engaged, or whether or not the engine brake hydraulic friction engagement device is in the engaged state. If the determination at SA3 is negative, the engine brake operation state switching gear is set to the engine brake operation state, and therefore SA4 is executed.
[0032]
SA4 corresponds to the turning travel determination means 112, in which whether or not the vehicle is turning is determined based on the steering angle of the steering wheel or the lateral acceleration (lateral G) acting on the vehicle. To be judged. If the determination of SA4 is negative, the engine transmission is applied to the power transmission path of the automatic transmission 14 and the vehicle is not turning and the relationship between the vehicle acceleration and the road surface gradient is not impaired. Therefore, in SA5, the gradient determination is permitted to be performed, and the gradient determination prohibition flag X indicating prohibition of the gradient determination is prohibited. _SJIH Is cleared to “0”.
[0033]
However, when the determination at SA3 is affirmed or when the determination at SA4 is affirmative, the engine brake operation state switching gear is in an engine brake non-operation state or is turning, and vehicle acceleration And the road gradient no longer correspond to each other, so in SA6 corresponding to the road gradient determination prohibiting means 114, the gradient determination prohibition flag X _SJIH Is set to “1”.
[0034]
Next, in the uphill / downhill control routine of FIG. 7, in SB1, the gradient determination prohibition flag X _SJIH It is determined whether or not the content of “1” is “1”. When the determination of SB1 is affirmed, the routine is terminated, and the acceleration calculation operation of SB2 and the selection operation of the up / down slope shift map of SB5 and SB6 are prohibited.
[0035]
However, if the determination of SB1 is negative, the throttle valve opening θ in the flat road travel stored in advance in SB2 corresponding to the acceleration calculation means 104 _TH , The gear stage G of the automatic transmission 14, and the rotational speed N of the automatic transmission output shaft 42 _OUT And the reference acceleration MOBGBU, the actual throttle valve opening θ _TH , Gear stage G, and rotational speed N of automatic transmission output shaft 42 _OUT And the reference acceleration MOBGBU is calculated based on the rotational acceleration dN of the automatic transmission output shaft 42. _OUT Based on / dt, the actual acceleration MOGBGBW is calculated.
[0036]
Next, in SB3 corresponding to the road gradient determination means 106, whether or not the actual vehicle acceleration MOBGBW is equal to or lower than the reference acceleration MOBGBU by a predetermined value K1 (MOBGBW ≦ MOBBU-K1), that is, the vehicle acceleration. Since this corresponds to the road gradient, it is determined whether or not the actual road gradient (MOBGBW-MOBGBBU) has fallen below the uphill control start gradient (-K1). If the determination at SB3 is negative, the actual vehicle acceleration MOBGBW becomes equal to or higher than the reference acceleration MOBGBU by a predetermined value K2 at SB4 corresponding to the road gradient determination means 106 in the same manner ( MOBGBW ≧ MOBBU + K2), that is, since the vehicle acceleration corresponds to the road gradient, it is determined whether or not the actual road gradient (MOBGBW−MOBGBU) exceeds the downhill control start gradient (K2). .
[0037]
If the determination at SB4 is negative, the slope is not high enough to start uphill control or downhill control, and the routine is terminated. However, if the determination at SB3 is affirmative, at SB5 corresponding to the uphill / downhill shift map switching means 108, the normal shift map of FIG. 5 is switched to a preset uphill shift map. . If the determination at SB4 is affirmative, at SB6 corresponding to the uphill / downhill shift map switching means 108, the normal shift map of FIG. 5 is switched to a preset downhill shift map. It is done.
[0038]
As described above, according to the present embodiment, when the engine brake non-operation state determination unit 110 (SA3) determines that the gear stage of the automatic transmission 14 is in the engine brake non-operation state, the road gradient The determination prohibition unit 114 (SA6) prohibits road gradient determination based on vehicle acceleration by the road gradient determination unit 106 (SB3, SB4). Accordingly, road gradient determination is prohibited when the vehicle acceleration does not necessarily reflect the road gradient, so that the accuracy of road gradient determination is maintained. At the same time, it is also preferable to prevent the drivability from being impaired by performing the uphill control or the downhill control based on the road gradient determination where accuracy cannot be obtained.
[0039]
Further, according to the present embodiment, the turning travel determination means 112 (SA4) for determining that the vehicle is turning is provided, and the road gradient determination prohibiting means 114 (SA6) is provided by the turning travel determination means 112. When it is determined that the vehicle is turning, road gradient determination based on vehicle acceleration by the road gradient determination unit 106 (SB3, SB4) is prohibited, and acceleration calculation by the acceleration calculation unit 104 is prohibited. In addition, since the road gradient determination is prohibited during cornering resistance during driving while the driving force is lost, that is, when the vehicle acceleration does not necessarily reflect the road gradient, the accuracy of the road gradient determination is maintained. In addition, it is preferable that the drivability is impaired by unnecessarily restricting the high-speed gear stage of the automatic transmission by executing the uphill control or the downhill control based on the road gradient determination where accuracy is not obtained. Is prevented.
[0040]
Further, according to the present embodiment, the actual throttle valve opening θ is obtained from the preset normal shift diagram (basic shift diagram) in FIG. _TH The vehicle speed V is determined by the shift control means 100 that makes a shift determination based on the vehicle speed V and outputs a shift output for causing the automatic transmission 14 to execute the shift determined for the shift, and the road gradient determination means 106 (SB3, SB4). Is determined to be a preset uphill / downhill control start gradient, the uphill / downhill shift map switching means 108 for switching to the uphill / downhill shift map for limiting the high speed gear of the automatic transmission 14 is determined. SB5, SB6) are further provided, and the high-speed gear stage of the automatic transmission is unnecessarily limited by executing the uphill control or the downhill control based on the road gradient determination where accuracy cannot be obtained. Thus, the drivability is preferably prevented from being impaired.
[0041]
As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.
[0042]
For example, the road gradient determination prohibiting unit 114 described above prohibits the acceleration calculation operation by the acceleration calculation unit 104 and the road gradient determination operation by the road gradient determination unit 106, but either one may be prohibited. It is. That is, in FIG. 7, SB1 may be provided between SB2 and SB3, or SB3 may be executed after the determination of SB1 is denied.
[0043]
Further, in the automatic transmission 14 of the above-described embodiment, the engine brake operation state switching gear stage includes an engine brake hydraulic friction engagement device for making the engine brake operation state, and the power from the engine to the drive wheel. Although the one-way clutch engaged in the power-on state is provided, only one of them may be provided.
[0044]
Moreover, although the uphill / downhill control means 102 of the above-mentioned embodiment performs the uphill control and the downhill control, it does not matter even if it executes any one of the controls.
[0045]
Further, although the automatic transmission 14 of the above-described embodiment has five forward speeds, it may be four forward speeds or six forward speeds, and an electric motor may be used instead of the engine 10.
[0046]
In the above-described embodiment, the uphill / downhill control and the road gradient determination are prohibited for the first gear to the third gear, but the uphill / downhill control and the road gradient determination are prohibited only for the third gear. You can go.
[0047]
Although not illustrated one by one, the present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram illustrating the configuration of an automatic transmission for a vehicle that is shift-controlled by a shift control apparatus according to an embodiment of the present invention.
2 is a chart showing a relationship between a combination of operations of a plurality of solenoid valves or hydraulic friction engagement devices and a gear stage established thereby in the automatic transmission of FIG. 1; FIG.
FIG. 3 is a diagram for explaining an electrical configuration of a control device provided in the vehicle of FIG. 1;
4 is a functional block diagram illustrating a main part of a control function of the shift electronic control device of FIG. 3; FIG.
FIG. 5 is a diagram showing a shift diagram used in the shift control means of FIG. 3;
6 is a flowchart for explaining a main part of the control operation of the shift electronic control device of FIG. 3, and is a diagram showing a gradient determination prohibiting control routine. FIG.
FIG. 7 is a flowchart for explaining a main part of the control operation of the shift electronic control device of FIG. 3, and showing an uphill / downhill control routine;
[Explanation of symbols]
14: Automatic transmission
100: Shift control means
102: Uphill / downhill control means
104: Acceleration calculation means
106: Road slope determination means
108: Uphill / downhill shift diagram switching means
110: Engine brake non-operation state determination means
114: Road slope determination prohibition means

Claims (1)

Road gradient for determining a road gradient based on vehicle acceleration in a vehicle in which the gear stage of the automatic transmission has an engine brake operation state where the engine brake is effective and an engine brake non-operation state where the engine brake is not effective A vehicle road gradient determination device including a determination means,
Engine brake non-operation state determination means for determining that the gear stage is in an engine brake non- operation state based on an operation state of an engine brake friction engagement device and a solenoid valve indicating the operation of the one-way clutch ;
Road gradient determination prohibiting means for prohibiting road gradient determination based on vehicle acceleration by the road gradient determining means when it is determined by the engine brake inactive state determining means that the engine stage is in an engine brake inactive state. And a vehicle road gradient judging device.

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