JP3683340B2 - Control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission control device, and more particularly, to an automatic transmission control device that performs downshifting when a vehicle is decelerated.
[0002]
[Prior art]
A system that obtains sufficient engine braking force and fuel efficiency improvement by fuel cut by shifting down the shift position of the automatic transmission to the low speed side when the vehicle decelerates has been known (Japanese Patent Publication No. 62). -9774). In a system similar to this, there has also been proposed a method for determining the shift position on the low speed side to be shifted down based on the current shift position and the deceleration of the vehicle (Japanese Patent Laid-Open No. 1-269748).
[0003]
In addition, when the vehicle is determined to travel uphill or downhill (hereinafter referred to as “uphill / downhill travel”), and when it is determined to travel uphill / downhill, the shift position is determined using a shift map (shift characteristics) that is different from when traveling on a flat road. There has been proposed a control device that determines the value (Japanese Patent Laid-Open No. 5-71635).
[0004]
[Problems to be solved by the invention]
In the control device described in Japanese Patent Laid-Open No. 5-71635, deceleration downshift control according to the vehicle speed and the deceleration of the vehicle is not performed. For example, the method disclosed in Japanese Patent Laid-Open No. 1-269748 is used as it is. When applied, there were the following problems.
[0005]
In other words, the shift map for uphill / downhill travel is set as shown in FIG. 9A, for example (the horizontal axis is the vehicle speed VP, the vertical axis is the accelerator pedal depression amount APFZ), and the deceleration for flat road travel. For example, the downshift map is set as shown in FIG. 9B (the horizontal axis is the vehicle speed VP, and the vertical axis is the deceleration DVSFT), so the vehicle speed VP is the same in the portions indicated by arrows A and B in FIG. However, when the shift map to be used is switched, the selected shift position is different. As a result, there has been a problem that drivability is deteriorated when deceleration downshift control is started during traveling on an uphill / downhill or when normal control returns from the deceleration downshift control.
[0006]
The present invention has been made to solve this problem, and provides a control device for an automatic transmission that can appropriately perform deceleration downshift control during uphill / downhill traveling and maintain good drivability. For the purpose.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a deceleration state determining means for determining a predetermined deceleration state of the vehicle, and a first predetermined shift when the predetermined deceleration state of the vehicle is determined by the deceleration state determining means. In a control device for an automatic transmission comprising a deceleration downshift control means for performing a downshift control of the automatic transmission of the vehicle using a map, an uphill / downhill state determination means for determining a predetermined uphill / downhill state of the vehicle; An uphill / downhill shift control means for controlling a shift position of the automatic transmission when the predetermined uphill / downhill state of the vehicle is determined by the uphill / downhill state determination means, and the deceleration downshift control means includes: If the predetermined deceleration state of the vehicle is determined when the uphill / downhill shift control means is operating, a shift down control of the automatic transmission is performed using a second predetermined shift map. In which it was to be carried out.
[0008]
According to the present invention, when the predetermined deceleration state of the vehicle is determined during the uphill / downhill shift control, the downshift control is performed using the second predetermined shift map.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
FIG. 1 is a diagram showing a configuration of an automatic transmission mounted on a vehicle according to an embodiment of the present invention and a control device thereof. An automatic transmission 21 is connected to a crankshaft 20 of an internal combustion engine 1. The automatic transmission 21 is connected to the crankshaft 20 and includes a torque converter 22 having a pump blade 22a and a turbine blade 22b, a lockup clutch 23 for connecting the pump blade 22a and the turbine blade 22b, and a torque converter 22 A gear mechanism 24 connected to the output side, and a hydraulic control mechanism 25 that controls operations of the lockup clutch 23 and the gear mechanism 24 are provided.
[0011]
The hydraulic control mechanism 25 includes an on / off type solenoid valve (hereinafter referred to as “A solenoid valve”) 25 a that switches between engagement and disengagement of the lockup clutch 23, and an A solenoid valve 25 a is turned on, and the lockup clutch 23 is engaged. A duty control type solenoid valve (hereinafter referred to as “B solenoid valve”) 25 b for controlling the engagement pressure when in the combined state, and a speed change actuator 25 c for controlling the shift position (gear ratio) of the gear mechanism 24. Yes. The A solenoid valve 25a, the B solenoid valve 25b, and the speed change actuator 25c are connected to an electronic control unit (hereinafter referred to as “ECU”) 2 for automatic transmission control. The ECU 2 is connected via the A solenoid valve 25a and the B solenoid valve 25b. Then, the engagement state of the lockup clutch 23 is controlled, and the shift position of the gear mechanism 24 is controlled via the speed change actuator 25c.
[0012]
The automatic transmission 21 is provided with a shift position sensor 27 that detects the shift position SRTDG of the gear mechanism 24, and the detection signal is supplied to the ECU 2.
[0013]
The output of the engine 1 is transmitted from the crankshaft 20 through the torque converter 22, the gear mechanism 24, and the differential device 31 to the left and right drive wheels 32 and 33 in order, and drives them. A vehicle speed sensor 28 for detecting the vehicle speed VP of the vehicle is provided on the output side of the automatic transmission 21, and the detection signal is supplied to the ECU 2.
[0014]
The engine 1 includes a throttle valve opening sensor 3 that detects an opening θTH of a throttle valve 1b provided in the middle of the intake pipe 1a, an engine water temperature sensor 4 that detects an engine cooling water temperature TW, and an engine speed NE. An engine speed sensor 5 for detection is provided, and detection signals from these sensors are supplied to the ECU 2. The engine speed sensor 5 outputs a TDC signal pulse at a predetermined crank angle position every 180 ° rotation of the crankshaft 20 and supplies it to the ECU 2.
[0015]
The throttle valve 1b is connected to a throttle actuator 34 made of, for example, an electric motor, and the throttle actuator 34 is connected to the ECU 2. The ECU 2 is connected to an accelerator opening sensor 35 for detecting an accelerator pedal depression amount (hereinafter referred to as “accelerator opening”) APFZ of the vehicle, and the detected signal is supplied. Then, the ECU 2 controls the throttle valve opening degree θTH according to the accelerator opening degree APFZ and the like. That is, in the present embodiment, the accelerator pedal and the throttle valve 1b are not mechanically connected, and the throttle valve opening θTH is controlled according to the accelerator opening AP and other operating conditions.
[0016]
The ECU 2 is further connected to a selection lever position sensor 36 for detecting a selection lever position for selecting an operation mode of the automatic transmission 21 and a brake switch 37 for detecting depression of a brake pedal. To be supplied. In the present embodiment, as the drive range, the D4 range for automatically selecting the shift position in the range from the first speed to the fourth speed, and the D3 range for automatically selecting the shift position in the range from the first speed to the third speed. And are provided.
[0017]
The ECU 2 is connected to an engine control electronic control unit (not shown) that controls the amount of fuel supplied to the engine 1 (opening time of the fuel injection valve), ignition timing, and the like, and transmits control parameter information to each other. It is configured as follows.
[0018]
The ECU 2 shapes input signal waveforms from the various sensors described above, corrects the voltage level to a predetermined level, converts an analog signal value into a digital signal value, and a central processing circuit (CPU). Drive signals to the A solenoid valve 25a, the B solenoid valve 25b, and the speed change actuator 25c, and a storage circuit including a ROM and a RAM for storing various calculation programs executed by the CPU, various maps and calculation results to be described later. An output circuit for controlling the engagement state of the lockup clutch 23, the shift position, and the throttle valve opening θTH based on detection signals of various sensors. In addition, the process demonstrated with reference to a flowchart below is performed by CPU of ECU2.
[0019]
2 and 3 are flowcharts of processing for calculating the shift position command value SFCMD output to the speed change actuator 25c, and this processing is executed every predetermined time (for example, 20 msec).
[0020]
First, in step S1, the shift position command value SFTCMD (previous calculation value) is stored as the previous value SFTCMD0. Next, it is determined whether or not the vehicle speed VP is higher than a deceleration determination threshold VSFTD (for example, 50 km / h) (step S2). If VP ≦ VSFTD, the downcount timer tmDEC2 is set to a predetermined time TDEC2 and started. (Step S5), an accelerator indicating "1" that the predetermined driving state (the driving state in which all the answers to Steps S2, S3, and S4 are affirmative: high vehicle speed accelerator on high gear ratio state) has continued for a predetermined time TDEC2 or more. The off timer permission flag FDECCAPOF is set to “0” (step S7), and the process proceeds to step S27.
[0021]
In step S27, a predetermined time TDECCSFT to be set in the accelerator-off continuation timer tmDECCSFT is determined according to the vehicle speed VP, and the predetermined time TDECCSFT is set in the timer tmDECCSFT and started. The predetermined time TDECSFT is set to a larger value as the vehicle speed VP is higher. Next, a deceleration shift down flag FDECCSFT, which indicates that the deceleration shift down process is being executed, is set to “0” (step S28), and the process proceeds to step S31 (FIG. 3).
[0022]
On the other hand, when VP> VSFTD in step S2, it is determined whether the accelerator opening APFZ is larger than a predetermined lower limit opening APFZOG (for example, 1.5 degrees) (step S3), and when APFZ> APFZOG, It is determined whether the overall gear ratio IGEAR is equal to a predetermined high speed gear ratio SFTAPOF (for example, a value corresponding to the fourth speed) (step S4). When IGEAR ≠ SFTAPOF, the process proceeds to step S5. When IGEAR = SFTAPOF, it is determined whether or not the value of the timer tmDEC2 is “0”. If tmDEC2> 0 and the predetermined time TDEC2 has not elapsed, the process proceeds to step S7. If tmDEC2 = 0, the accelerator off timer permission flag FDECAPOF is set to “1” (step S8), and the process proceeds to step S27.
[0023]
If APFZ ≦ APFZOG in step S3, the timer tmDEC2 is set to start for a predetermined time TDEC2 (step S11), and whether or not the brake switch 37 is turned on, that is, whether or not the brake pedal is depressed. (Step S12), and when the brake switch is OFF, it is determined whether or not the deceleration shift down flag FDECCSFT is “1” (step S14). If FDECCSFT = 1 and the deceleration downshift process is being performed, the process proceeds to step S25.
[0024]
On the other hand, when FDECCSFT = 0 and the deceleration shift down process is not in progress, it is determined whether or not the vehicle speed VP is equal to or higher than a predetermined vehicle speed VDECCSFT (for example, 50 km / h) (step S15). It is determined whether or not the speed DVSFT (= VP (current value) −VP (previous value)) is equal to or lower than a predetermined deceleration DVDEC2 (eg, 0 km / h) (step S16), and if DVSFT ≦ DVDEC2, the accelerator off timer It is determined whether or not the permission flag FDECAPOF is “1” (step S17). If any answer from step S15 to S17 is negative (NO), the process proceeds to step S27. If all the answers from step S15 to S17 are positive (YES), the value of the timer tmDECCSFT started in step S27 is It is determined whether or not “0”. When tmDECSFT> 0 and the accelerator pedal is turned off and before a predetermined time TDECCSFT elapses, the process proceeds to step S28. When tmDECCSFT = 0 and the predetermined time TDECCSFT elapses, a deceleration shift down flag is set. FDECCSFT is set to “1” (step S26), and the process proceeds to step S31 (FIG. 3).
[0025]
When the brake switch 37 is on in step S12, the process proceeds to step S13, where it is determined whether or not the deceleration DVSFT is equal to or less than a predetermined deceleration DVDEC (for example, 0 km / h), and when DVSFT> DVDEC and the vehicle is not decelerating. Advances to step S14. If DVSFT ≦ DVDEC and the vehicle is decelerating, it is determined whether or not the deceleration shift down flag FDECCSFT is “1” (step S21). If FDECCSFT = 1, the process immediately proceeds to step S25. When FDECCSFT = 0, the routine proceeds to step S22, where it is determined whether or not the shift position command value SFTCMD is 4 (4th speed), and when SFTCMD = 4, the deceleration shift map switching vehicle speed VCHK (FIG. 6, step). S107) is set to the detected vehicle speed VP (step S24), and if SFTCCMD = 4, the deceleration shift map switching vehicle speed VCHK is set to the maximum value VCHKMAX (for example, FFFF (hexadecimal number)) (step S23). The process proceeds to step S25.
[0026]
In step S25, it is determined whether the accelerator off timer permission flag FDECAPOF is “1”. If FDECCAPOF = 0, the process proceeds to step S27. If FDECCAPOF = 1, the deceleration shift down flag FDECCSFT is set to “1”. "(Step S26), and the process proceeds to step S31.
[0027]
According to the above processing, the deceleration shift down flag FDECCSFT is set to “1” in the following cases, and the deceleration shift down processing (step S36) described later is executed.
[0028]
1) While the accelerator is on (APFZ> APFZOG), the high vehicle speed (VP> VSFTD) and the high speed shift position (IGEAR = SFTAPOF) continue for a predetermined time TDEC2 (FDECAPOF = 1), and then the accelerator is off (APFZ ≦ APFZOG). ) When the brake is off and the high vehicle speed (VP ≧ VDECSFT) deceleration state (DVSFT ≦ DVDEC2) continues for a predetermined time TDECCSFT (steps S12, S14 to S18 → S26), and thereafter the high vehicle speed (VP> VSFTD), the accelerator is off. Is continued (in the case of proceeding directly from step S14 to S25).
[0029]
2) While the accelerator is on (APFZ> APFZOG), the high vehicle speed (VP> VSFTD) and the high gear ratio (IGEAR = SFTAPOF) continue for a predetermined time TDEC2 (FCECAPOF = 1), and then the high vehicle speed (VP> VSFTD). ) When the accelerator is off and the brake is on and the vehicle is decelerating (DVSFT ≦ DVDEC) (steps S12, S13, S25 → S26), and thereafter the high vehicle speed (VP> VSFTD), and when the accelerator is off (directly from step S21) When proceeding to S25).
[0030]
In step S31 of FIG. 3, the basic shift position SFTMM search process (FIG. 4) is executed.
[0031]
In step S51 of FIG. 4, the shift threshold value VPM12UP (shift-up threshold value from the first speed to the second speed), VPM23UP (shift-up threshold value from the second speed to the third speed), VPM21DW (2) according to the accelerator opening APFZ Speed-down threshold from 1st speed), VPM32DW (shift-down threshold from 3rd speed to 2nd speed). Specifically, for example, the shift map shown in FIG. 7A is searched, and the VP values on the boundary lines (first speed and second speed, and second speed and third speed) corresponding to the detected APFZ value are obtained. Ask. FIG. 7A shows a shift-down map, but the shift-up threshold value is searched from a shift-up map (not shown).
[0032]
In a succeeding step S52, it is determined whether or not the value of the climbing slope road travel parameter PROS is “3”. The ascending / descending road travel parameter PROS is calculated by a process (not shown), and when the value is “3”, it travels on a heavy climbing slope (climbing on a relatively large slope), and when it is “2”, it travels on a heavy descending slope. (Travel down a slope with a relatively large slope), “1” for light climbing and downhill travel (climbing or going down a slope with a relatively small slope), “flat” for values other than “1, 2, 3” Indicates road driving. The uphill / downhill road travel parameter PROS is calculated based on a comparison result between the expected acceleration calculated according to the engine operating state such as the throttle valve opening θTH and the actual acceleration.
[0033]
When PROS = 3 in step S52 and the vehicle is traveling on a heavy uphill road, the vehicle speed VP is searched for a heavy uphill road threshold VPM43DW3 (shift down threshold from the fourth speed to the third speed) according to the accelerator opening APFZ. . In this case, in order to select a shift position suitable for traveling on an uphill / downhill road, a downshift map for heavy uphill road (not shown) is used instead of the map (for flat road) shown in FIG. In subsequent step S56, a heavy uphill road upshift map is searched according to the accelerator opening APFZ, a heavy uphill road threshold VPM34UP2 is calculated, and the process proceeds to step S60.
[0034]
If PROS = 3 in step S52, it is determined whether or not PROS = 2 (step S53). If PROS = 2 and the vehicle is traveling on a heavy downhill road, the heavy load shown in FIG. The downhill shift down map is searched to calculate a heavy downhill threshold VPM43DW2 (shift down threshold from the fourth speed to the third speed), and the process proceeds to step S56.
[0035]
If it is not PROS = 2 in step S53, it is determined whether or not PROS = 1. If PROS = 1 and the vehicle is traveling on a light uphill / downhill road, a search for a light up / down slope upshift map and a shift down map is performed. Then, the threshold value VPM34UP1 (shift-up threshold value from the third speed to the fourth speed) and VPM43DW1 (shift-down threshold value from the fourth speed to the third speed) are calculated (step S59). When PROS = 1 is not satisfied, a flat road shift-up map and a shift-down map (FIG. 7A) are searched, and a flat road threshold VPM34UP0 (shift-up threshold from the third speed to the fourth speed) and VPM43DW0 ( A shift-down threshold value from the fourth speed to the third speed is calculated (step S58).
[0036]
In the subsequent step S60, the threshold value calculated in each of the above steps is compared with the vehicle speed VP in accordance with the current shift position and the uphill / downhill parameter PROS, the basic shift position SFTMM is determined based on the comparison result, and this processing is performed. finish. For example, when the current shift position is the third speed, if the VP value exceeds the shift-up threshold value from the third speed to the fourth speed, SFTMM = 4 and the VP value is a shift-down threshold value from the third speed to the second speed. SFTMM = 2 when it is less than, and SFTMM = 3 otherwise.
[0037]
Returning to FIG. 3, in step S <b> 32, it is determined whether or not the basic shift position SFTMM selected in step S <b> 31 is “4” (fourth speed). If SFTMM = 4, the selection lever position is in the D3 range. (Step S33), if it is in the D3 range, the basic shift position SFTMM = 3 (3rd speed) is set (step S34), and the process proceeds to step S35. Otherwise, the process proceeds to step S35 as it is.
[0038]
In step S35, it is determined whether or not the deceleration shift down flag FDECCSFT is “1”. If FDECCSFT = 1, the deceleration shift down processing (FIG. 5) in step S36 is executed, and the process proceeds to step S42.
[0039]
If FDECCSFT = 0 in step S35, it is determined whether or not the value of the downcount timer tmSFTD in which the predetermined time TSFTD is set in the deceleration shift down process (step S36) is “0” (step S37). Then, before tmSFTD> 0 and a predetermined time TSFTD elapses after completion of the deceleration shift down process, it is determined whether or not the basic shift position SFTMM is larger than the previous value SFTCMD0 of the shift position command value. If SFTMM ≦ SFTCMD0, The value of the timer tmSFTD is set to “0” (step S40), the shift position command value SFTCMD is set to the basic shift position SFTMM (step S41), and the process proceeds to step S42.
[0040]
On the other hand, if SFTMM> SFTCMD0 in step S38, the shift position command value SFTCMD is set to the previous value SFTCMD0 (step S39), and the process proceeds to step S42. If tmSFTD = 0 in step S37 and a predetermined time TSFTD has elapsed after completion of the deceleration downshift process, steps S40 and S41 are immediately executed, and the process proceeds to step S42.
[0041]
In step S42, it is determined whether or not the shift position command value SFTCMD is “4”. When SFTCCMD = 4, it is determined whether or not the selection lever position is in the D3 range (step S43). Corrects the shift position command value SFCMD to “3” (step S44), and proceeds to step S45. Otherwise, the process immediately proceeds to step S45. In step S45, the basic shift position SFTMM is set to the shift position command value SFTCMD, and this process ends.
[0042]
Next, the deceleration shift down process in step S36 will be described with reference to FIG.
[0043]
In step S71, it is determined whether or not the detected actual shift position SRTDG is “4”. If SRTDG = 4, the subtraction term DSFT used in step S83 is set to the value DSFT4 for the fourth speed (step S71). (S73) If SRTDG = 4 is not satisfied, the value DSFT3 for the third speed is set (step S72), and the process proceeds to step S74.
[0044]
In step S74, it is determined whether or not the compressor of the air conditioner driven by the engine 1 is in operation. If it is in operation, the predetermined engine speed NCHK used in step S81 is set to the value NCHKH for turning on the air conditioner. If it is not in operation, it is set to the value NCHKB for turning off the air conditioner (step S75), and the process proceeds to step S77.
[0045]
In step S77, a SFTCHK search process (FIG. 6) for searching for a controllable shift position SFTCHK during deceleration is executed.
[0046]
In step S101 in FIG. 6, it is determined whether or not the uphill / downhill road travel parameter PROS is “3”. When PROS = 3 and the road is running on the heavy uphill road, the heavy uphill road according to the deceleration DVSFT is determined. The shift down map (not shown) is searched and the heavy climbing slope threshold VPC43P3 (shift down threshold from 4th to 3rd) and VPC32P3 (shift down threshold from 3rd to 2nd) are calculated ( Step S104), the process proceeds to Step S109.
[0047]
When PROS = 2 and the vehicle is traveling on a heavy downhill road, the process proceeds from step S102 to S105, and a downshift map for heavy downhill road shown in FIG. 8B is retrieved according to the deceleration DVSFT. The threshold value VPC43P2 (shift-down threshold value from the fourth speed to the third speed) and VPC32P2 (shift-down threshold value from the third speed to the second speed) are calculated, and the process proceeds to step S109.
[0048]
When PROS = 1 and the vehicle is traveling on a light uphill / downhill road, the process proceeds from step S103 to S106, a light downhill road downshift map (not shown) is searched according to the deceleration DVSFT, and a light up / down slope threshold is obtained. VPC43P1 (shift down threshold value from 4th speed to 3rd speed) and VPC32P1 (shift down threshold value from 3rd speed to 2nd speed) are calculated, and the process proceeds to step S109.
[0049]
Here, the light downhill slope deceleration shift down map (not shown) is set to be shifted down on the low vehicle speed side and the high deceleration side compared to the heavy downhill road deceleration shift down map. The deceleration shift map for heavy climbing slopes (not shown) is set to be shifted down on the high vehicle speed side and the reduction speed side compared to the deceleration shift down map for heavy descending slopes.
[0050]
When the PROS value is neither 1, 2, or 3, that is, when traveling on a flat road, it is determined whether or not the deceleration shift map switching vehicle speed VCHK set in step S23 or S24 in FIG. 2 is lower than a predetermined vehicle speed VDWCHK. If VCHK <VDWCHK, a flat road low vehicle speed shift down map (not shown) is searched according to the deceleration DVSFT, and the flat road low vehicle speed threshold VPC43L (shift from 4th to 3rd gear) A down threshold value is calculated (step S110). Next, a low vehicle speed shift-down map is searched according to the deceleration DVSFT, and a low vehicle speed threshold VPC21L (second-speed to first-speed shift-down threshold) and VPC32L (third-speed to second-speed shift-down threshold) are calculated. (Step S111), the process proceeds to step S112.
[0051]
If VCHK ≧ VDWCHK in step S107, a flat road high vehicle speed shift down map shown in FIG. 7B is retrieved according to the deceleration DVSFT, and the flat road high vehicle speed threshold VPC43H (from 4th to 3rd speed) is retrieved. Downshift threshold) is calculated (step S108). In the following step S109, a high vehicle speed shift down map is searched according to the deceleration DVSFT, a high vehicle speed threshold VPC21H (shift down threshold from the second speed to the first speed) is calculated, and the process proceeds to step S112.
[0052]
In step S112, the controllable shift position SFTCHK at the time of deceleration is determined based on the threshold value calculated in the above steps, the PROS value, the current shift position, and the detected vehicle speed VP. For example, when traveling on a heavy downhill road and the current shift position is the fourth speed, if VP <VPC43P2, SFTCHK = 3.
[0053]
In the following step S113, it is determined whether or not the selection lever position is in the D3 range. If it is in the D3 range, it is determined whether or not the calculated SFTCHK value is “4” (step S114), and SFTCHK = 4. If there is, the SFTCHK value is changed to “3” (step S115). Otherwise, the process is immediately terminated.
[0054]
As described above, in the process of FIG. 6, the deceleration downshift map for the uphill / downhill road (FIG. 8B) regarding the downshift from the 4th speed to the 3rd speed and the 3rd speed to the 2nd speed while traveling on the uphill / downhill road. )) Is used to select the shift position. Here, the threshold value of the deceleration shift down map for the uphill / downhill road is set so that the deviation from the threshold value of the shift map for the uphill / downhill road used in other than the deceleration downshift process ((a) in the figure) becomes small. Therefore (see FIG. 9), even when the map to be used is changed from the one shown in FIG. 8 (a) to the one shown in FIG. 8 (b) or vice versa, the selected shift position changes as the map changes. Therefore, good drivability can be maintained.
[0055]
Returning to FIG. 5, in step S78, it is determined whether or not the controllable shift position SFTCHK during deceleration determined in step S77 is equal to or greater than the previous shift position command value SFCMD0. If SFTCHK <SFTCMD0, the deceleration shift position SFDEC is determined. Is set to the controllable shift position SFTCHK during deceleration (step S79), and the process proceeds to step S86.
[0056]
If SFTCHK ≧ SFTCMD0 in step S78, it is determined whether or not the actual shift position SRTDG is the third speed or the fourth speed, and if it is not the third speed or the fourth speed, the deceleration shift position SFTDEC is set to the previous shift position command value. Set to SFTCMD0 (step S82), and proceed to step S86. When the actual shift position is the third speed or the fourth speed, it is determined whether or not the predicted engine speed HNE is equal to or lower than the predetermined engine speed NCHK determined in step S75 or S76 (step S81). The predicted engine speed HNE is calculated according to the change amount DNSFT (= NE (current value) −NE (previous value)) of the engine speed NE and the engine speed NE (current value).
[0057]
If HNE> NCHK in step S81, the process proceeds to step S82. If HNE ≦ NCHK, the deceleration shift position SFTDEC is calculated by the following equation (step S83).
[0058]
SFTDEC = SFTCMD0-DSFT
Here, DSFT is a subtraction term set in step S72 or S73.
[0059]
In the following step S84, it is determined whether or not the calculated deceleration shift position SFTDEC is smaller than “2”. If SFTDEC ≧ 2, immediately, and if SFTDEC <2, SFTDEC = 2 (step S85). Proceed to step S86.
[0060]
In step S86, it is determined whether or not the deceleration shift position SFTDEC is equal to or greater than the previous shift position command value SFTCMD0. If there is, the deceleration shift position SFTDEC is set (step S88), and the process proceeds to step S89. In step S89, a predetermined time TSFTD is set in the deceleration shift down timer tmSFTD, and this process ends.
[0061]
【The invention's effect】
As described above in detail, according to the present invention, when the predetermined deceleration state of the vehicle is determined during the uphill / downhill shift control, the downhill control is performed using the second predetermined shift map. It is possible to appropriately perform deceleration downshift control during traveling and maintain good drivability.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an automatic transmission of a vehicle and a control device thereof according to an embodiment of the present invention.
FIG. 2 is a flowchart of a process for calculating a shift position command value for an automatic transmission.
FIG. 3 is a flowchart of processing for calculating a shift position command value for an automatic transmission.
4 is a flowchart showing in detail a part of the processing of FIG. 3;
FIG. 5 is a flowchart showing a part of the processing of FIG. 3 in detail.
6 is a flowchart showing a part of the processing of FIG. 5 in detail.
7 is a diagram showing a table used in the processing of FIGS. 4 and 6. FIG.
FIG. 8 is a diagram showing a table used in the processing of FIGS. 4 and 6;
FIG. 9 is a diagram for explaining a problem of the prior art.
[Explanation of symbols]
1 Internal combustion engine
2 Electronic control unit
5 Engine speed sensor
21 Automatic transmission
24 Gear mechanism
25 Hydraulic control mechanism
28 Vehicle speed sensor
35 Accelerator position sensor

Claims (1)

Deceleration state determination means for determining a predetermined deceleration state of the vehicle, and when the predetermined deceleration state of the vehicle is determined by the deceleration state determination means, the automatic transmission of the vehicle using a first predetermined shift map In a control device for an automatic transmission comprising a deceleration downshift control means for performing downshift control of
Uphill / downhill state determination means for determining a predetermined uphill / downhill state of the vehicle;
An uphill / downhill shift control means for controlling the shift position of the automatic transmission when the predetermined uphill / downhill state of the vehicle is determined by the uphill / downhill state determination means;
The deceleration downshift control means uses the second predetermined shift map to determine the automatic transmission when the uphill / downhill shift control means is operating and a predetermined deceleration state of the vehicle is determined. A control device for an automatic transmission, characterized by performing downshift control.

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