JP2004316867A - Control device for vehicle and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute shift control instantaneously determining whether a trailer is in a towed condition or not right after started. <P>SOLUTION: An ECU 1000 controls a vehicle which is mounted with an engine 100 and a torque converter 200 for transmitting driving force from the engine 100 to an automatic transmission 300. The ECU 1000 includes a circuit for detecting an acceleration opening of a vehicle by a driver, a circuit for computing a speed ratio as the ratio of an input rotating speed NE to an output rotating speed NT of the torque converter 200, and a circuit for determining whether it is a timing for towing and starting the trailer or not in accordance with the acceleration opening, the speed ratio and an output rotating speed NOUT of the automatic transmission 300. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device and a control method for controlling an automatic transmission provided on the output side of a driving force source such as an engine, and in particular, to a high load traveling state such as a case where another vehicle is towed by the own vehicle. The present invention relates to a control device and a control method for realizing a suitable shift.
[0002]
[Prior art]
An automatic transmission mounted on a vehicle is configured to have a transmission mechanism that is connected to an engine via a torque converter and the like and has a plurality of power transmission paths. For example, the automatic transmission is configured based on an accelerator opening and a vehicle speed. The power transmission path is automatically switched, that is, the gear ratio (gear stage) is automatically switched. In general, a vehicle having an automatic transmission is provided with a shift lever operated by a driver, and a shift position (for example, a reverse travel position, a neutral position, a forward travel position) is set based on the shift lever operation. The automatic shift control is performed within the thus set shift position (usually, within the forward running position). At this time, a shift map serving as a reference for determining switching of the gear ratio of the automatic transmission is stored. The shift map defines a shift line for controlling a shift, specifically, an upshift line and a downshift line, using the traveling state of the vehicle, for example, the vehicle speed and the accelerator opening as parameters.
[0003]
Then, when a signal indicating the traveling state of the vehicle is input to the shift control device, a shift determination is performed based on the input signal and the shift map. Here, when the determination to switch the gear ratio is established, a gearshift signal is output from the gearshift control device, and the friction engagement device is engaged or released by the hydraulic control device, and gearshifting is performed.
[0004]
In setting such a shift map, a shift map having different shift control contents is prepared according to whether the gear ratio is set with emphasis on fuel efficiency or the gear ratio is set with emphasis on power performance. In addition to a technique for changing a shift map by a manual operation of a driver, a technique for automatically switching a shift map having different shift control contents according to a change in running load or the like has been proposed. In particular, there has been proposed a shift control device that can cope with a case where the running load changes due to a change in the vehicle weight due to a loaded load, such as a truck, or a case where the running load changes when the host vehicle pulls another vehicle. .
[0005]
Japanese Patent Laying-Open No. 2001-304384 (Patent Document 1) discloses a shift control in which a shift control suitable for a towing traveling state is performed and a rotation speed of a driving force source can be prevented from rising to a predetermined rotation speed or more. An apparatus is disclosed. This transmission control apparatus is capable of selectively switching a plurality of transmission control modes having different transmission control contents in order to control a transmission ratio of an automatic transmission provided on an output side of a driving force source. A shift control mode selection unit that selects the first shift control mode when the output control request for the driving force source is in a predetermined state, and when the first shift control mode is selected, A shift control mode switching unit configured to switch from the first shift control mode to the second shift control mode when a physical quantity related to the rotation speed of the driving force source shows a specific change.
[0006]
According to this shift control device, the first shift control mode is selected when the output control request for the driving force source is in a predetermined state, and when the first shift control mode is selected, When the physical quantity related to the rotation speed shows a specific change, the mode is switched from the first shift control mode to the second shift control mode. Therefore, the gear ratio is controlled in accordance with the state of change of the physical quantity due to the change of the running load of the vehicle.
[0007]
Japanese Patent Laying-Open No. 6-147304 (Patent Document 2) discloses an automatic transmission control device capable of estimating a vehicle weight and a traveling load, executing an accurate shift in accordance with the vehicle weight and the traveling load, and improving fuel efficiency. Is disclosed. The automatic transmission control device includes a load calculation unit that calculates a load of an automobile, an output torque estimation unit that calculates an output torque by referring to a torque characteristic of a drive system, and a running load that is estimated from the load and the output torque. A running load estimating unit, a storage unit for at least two shift schedules, and a shift schedule variable control unit that determines a shift schedule of the automatic transmission during actual running based on the running load and the shift schedule. Including.
[0008]
According to this automatic transmission control device, the load calculation unit calculates the load of the vehicle. The output torque estimating unit calculates the output torque with reference to the torque characteristics of the drive system. The running load estimating unit estimates the running load from the load and the output torque. The shift schedule variable control unit determines a shift schedule of the automatic transmission during actual running based on the running load and the shift schedule. As a result, the running load is estimated, and the shift is executed in accordance with the vehicle weight and the running load. Therefore, an optimum shift pattern is formed according to the driving environment (mountain road, multi-person riding), and the drivability is improved. When traveling on level ground, fuel efficiency can be improved as compared with the related art.
[0009]
Further, in order to perform such shift control, a technique for accurately calculating the vehicle weight has been proposed.
[0010]
Japanese Patent Laying-Open No. 2002-340660 (Patent Document 3) discloses a vehicle weight estimating device capable of accurately estimating a vehicle weight. This vehicle weight estimating device obtains a filtered acceleration by removing an low frequency component included in the detected acceleration, an acceleration detecting unit that detects the acceleration of the vehicle, a driving force estimating unit that estimates the driving force of the vehicle, and A filtered acceleration obtaining unit that performs filtering, a filtered driving force obtaining unit that obtains a filtered driving force by removing a low-frequency component included in the estimated driving force, and a value corresponding to an absolute value of the filtered acceleration. An acceleration integration unit that integrates only during a period to obtain an acceleration integration value, a driving force integration unit that integrates a value corresponding to the absolute value of the filtered driving force for a predetermined period to obtain a driving force integration value, and an acceleration integration value and driving A vehicle weight estimating unit for estimating the weight of the vehicle from the force integral value.
[0011]
According to the vehicle weight estimating apparatus, the absolute values of the filtered acceleration and the filtered driving force are obtained, and the values corresponding to the absolute values are integrated. As a result, since the value to be integrated is always a positive value, the period for integrating the value corresponding to the filtered acceleration and the value corresponding to the filtered driving force is set long regardless of the sign (positive or negative) of these values. However, the integral value of these values can be increased. As a result, the ratio of noise included in the integrated value can be reduced, so that the vehicle weight can be accurately estimated.
[0012]
Japanese Patent Laying-Open No. 2002-221442 (Patent Document 4) discloses a vehicle weight estimating device capable of accurately estimating a vehicle weight. The vehicle weight estimating device includes an acceleration detecting unit that detects the acceleration of the vehicle that transmits the generated torque of the prime mover to the driving wheels via a fluid torque converter, a driving force estimating unit that estimates the driving force of the vehicle, And a vehicle weight estimating unit for estimating the weight of the vehicle based on the estimated acceleration and the estimated driving force. And an estimation invalidation unit that invalidates the estimation of the vehicle weight by the vehicle weight estimation unit when it is determined that the vehicle is traveling on a downhill.
[0013]
The vehicle weight estimating device detects an acceleration of the vehicle by an acceleration detecting unit, estimates a driving force of the vehicle by a driving force estimating unit, and calculates the driving force based on the acceleration detected by the vehicle weight estimating unit and the estimated driving force. To estimate the weight of the vehicle. When the downhill traveling determination unit determines that the vehicle is traveling on a downhill, the estimation invalidation unit invalidates the estimation of the vehicle weight by the vehicle weight estimation unit. As a result, when the vehicle is traveling on a downhill road, the driving force of the vehicle is small, and it is difficult to estimate the driving force with sufficient accuracy. is there. Therefore, by invalidating the vehicle weight estimated when traveling on a downhill road, the estimation accuracy of the vehicle weight can be improved.
[0014]
[Patent Document 1]
JP 2001-304384 A
[0015]
[Patent Document 2]
JP-A-6-147304
[0016]
[Patent Document 3]
JP 2002-340660 A
[0017]
[Patent Document 4]
JP 2002-221442 A
[0018]
[Problems to be solved by the invention]
The shift control device disclosed in Patent Literature 1 detects that the vehicle is in a towing state based on the accelerator opening, the vehicle speed, and the acceleration, and delays a shift signal transmission timing in the towing state as compared with during normal traveling. However, in this shift control device, the vehicle speed calculated based on the output rotation speed of the automatic transmission is used to detect the towing state using the vehicle speed itself and the amount of change in the vehicle speed to perform shift control, so Immediately after the detection accuracy is not high, it is not possible to accurately detect the towing state.
[0019]
In the automatic transmission control device disclosed in Patent Document 2, a load is estimated from the input / output rotation speed of the torque converter, a vehicle weight is estimated from acceleration, a vehicle speed, and a throttle opening, and an appropriate shift is performed from the estimated load and vehicle weight. This is for setting the step. However, based on only the operating state of the torque converter, it cannot be accurately detected that the vehicle is in the towing state immediately after the vehicle starts moving.
[0020]
In the vehicle weight estimating devices disclosed in Patent Literature 3 and Patent Literature 4, even if the vehicle weight can be accurately calculated, it is necessary to integrate the driving force. Due to this integration time, the traction is performed immediately after the vehicle starts moving. The state could not be detected.
[0021]
The present invention has been made in order to solve the above-described problem, and an object of the present invention is to accurately determine whether or not the vehicle is in a towing state immediately after the vehicle starts when the vehicle is towing and starting another vehicle. An object of the present invention is to provide a control device and a control method for a vehicle, which can perform a shift control by making a determination.
[0022]
[Means for Solving the Problems]
A control device according to a first aspect of the present invention controls a vehicle equipped with a driving force source and a fluid coupling for transmitting a driving force from the driving force source to a transmission. This vehicle may tow another vehicle. The control device includes: first detection means for detecting an accelerator opening by a driver of the vehicle; second detection means for detecting an input rotation speed and an output rotation speed of the fluid coupling; Based on calculation means for calculating the ratio of the output rotation speed to the input rotation speed, the accelerator opening, the ratio, the brake signal, and the output rotation speed, it is the timing to tow and start another vehicle. Determining means for determining.
[0023]
According to the first invention, the ratio calculated by the calculation means based on the accelerator opening detected by the first detection means and the input rotation speed and the output rotation speed of the fluid coupling detected by the second detection means, Based on the output rotation speed detected by the second detection means, it can be determined whether or not it is time to tow and start another vehicle. For example, the accelerator opening is equal to or greater than a predetermined opening, the ratio is equal to or less than the predetermined ratio, and the output speed is 0 or the time rate of change of the output speed is predetermined. If the rate of change is equal to or less than the change rate, it is determined that it is time to tow and start the other vehicle. With this configuration, it is possible to immediately determine whether or not the vehicle is towing another vehicle based on the driver's accelerator operation or the like without using the time integrated values of the vehicle speed, the vehicle acceleration, and the driving force. You. As a result, it is possible to provide a vehicle control device capable of executing a shift control by accurately determining whether or not the vehicle is in a towing state immediately after the start when the own vehicle starts towing another vehicle. it can.
[0024]
In the control device according to the second aspect, in addition to the configuration of the first aspect, the determining means may determine that the accelerator opening is equal to or greater than the predetermined opening and the ratio is equal to or less than the predetermined ratio. If there is no brake signal input and the output rotational speed is 0, a means for determining that it is the timing to tow and start another vehicle.
[0025]
According to the second aspect, the ratio of the torque converter, which is one of the fluid couplings (speed ratio = output rotation speed / input rotation speed), is small despite the large accelerator opening. Towing another vehicle based on a first determination that the vehicle is in a large, high-load operating state, that is, a towing state, and that the vehicle is still stopped with a high load. It is possible to immediately judge whether or not the user is in the state. In particular, since the output speed of the torque converter is used instead of using the vehicle speed of the vehicle, the resolution is high, so that it is possible to accurately and immediately determine whether the vehicle is in the towing state. Note that, for the predetermined opening degree or more, the opening degree may be higher than the predetermined opening degree, and for the ratio less than the predetermined ratio, the ratio may be lower than the predetermined ratio. Is also good.
[0026]
The control device according to a third aspect of the present invention further includes, in addition to the configuration of the first aspect, means for calculating a time rate of change of the output rotation speed. The determining means determines that the other vehicle is open when the accelerator opening is equal to or greater than the predetermined opening, the ratio is equal to or less than the predetermined ratio, and the time change rate is equal to or less than the predetermined change rate. Means for determining that it is time to tow and start is included.
[0027]
According to the third aspect, the torque converter, which is one of the fluid couplings, has a small ratio (speed ratio = output speed / input speed) despite the large accelerator opening, so that the torque converter slips. Based on the first determination that the vehicle is in a towing state and the second determination that the time change rate of the output rotation speed of the torque converter is high with a high load, is the vehicle being towed by another vehicle? Judgment can be made immediately. In particular, because the time change rate of the output speed of the torque converter is used instead of using the acceleration of the vehicle, the resolution is high, so it is possible to accurately and immediately determine whether or not the vehicle is in the towing state. it can. Note that, for the predetermined opening degree or more, the opening degree may be higher than the predetermined opening degree, and for the ratio less than the predetermined ratio, the ratio may be lower than the predetermined ratio. Alternatively, when the time change rate is equal to or less than the predetermined change rate, the time change rate may be lower than the predetermined change rate.
[0028]
According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, the control device according to any one of the first to third aspects further includes a storage unit for storing a shift map of the transmission, and a towing unit for starting another vehicle by the determination unit. If it is determined that the timing is the timing, a change unit for changing a shift line on the shift map is further included.
[0029]
According to the fourth aspect, in a high load state in which another vehicle (trailer) is being pulled, the shift line of the shift map can be changed to quickly start the vehicle.
[0030]
In the control device according to a fifth aspect, in addition to the configuration of the fourth aspect, the transmission is an automatic transmission having a planetary gear type reduction mechanism. The changing means includes means for changing the upshift line on the shift map to a higher speed side.
[0031]
According to the fifth aspect of the present invention, in a high load state where another vehicle is being pulled, in the case of an automatic transmission having a planetary gear type reduction mechanism, a shift map (a map in which the horizontal axis represents the vehicle speed and the vertical axis represents the throttle opening). In ()), the upshift shift line from 1st to 2nd can be changed to the high speed side so that the vehicle can be started quickly.
[0032]
In the control device according to a sixth aspect, in addition to the configuration according to any one of the first to fifth aspects, the fluid coupling is a torque converter with a lock-up clutch. The control device further includes a unit for increasing the lock-up area of the lock-up clutch when it is determined by the determination unit that it is time to tow and start the other vehicle.
[0033]
According to the sixth aspect of the present invention, the temperature of the hydraulic oil of the automatic transmission is increased in the low speed ratio region of the torque converter. Performance can be improved.
[0034]
In a control device according to a seventh aspect, in addition to the configuration of any of the first to sixth aspects, the driving force source is an engine. When it is determined by the determination means that it is the timing to tow and start the other vehicle, the control device further includes means for changing the opening characteristic of the throttle valve of the engine to a tendency that the opening degree is larger than that in the normal state. Including.
[0035]
According to the seventh aspect, the opening characteristic of the throttle valve of the engine (the characteristic of the opening of the electromagnetic throttle valve with respect to the accelerator opening) is changed to the opening characteristic that makes the opening larger than in the normal state. The running performance of the vehicle under a high load can be improved.
[0036]
A control method according to an eighth aspect of the present invention controls a vehicle equipped with a driving force source and a fluid coupling for transmitting the driving force from the driving force source to a transmission. A vehicle may tow another vehicle. In this control method, a first detection step of detecting an accelerator opening by a driver of a vehicle, a second detection step of detecting an input rotation speed and an output rotation speed of a fluid coupling, and an input rotation of the fluid coupling A calculating step of calculating a ratio of the output rotation speed to the number of rotations, and a determining step of determining, based on the accelerator opening, the ratio, the brake signal, and the output rotation speed, a timing of towing and starting another vehicle. And
[0037]
According to the eighth aspect, the ratio calculated by the calculating means based on the accelerator opening detected in the first detection step and the input rotation number and the output rotation number of the fluid coupling detected in the second detection step It is possible to determine whether or not it is time to tow and start another vehicle based on the output rotation speed detected in the second detection step. For example, the accelerator opening is equal to or greater than a predetermined opening, the ratio is equal to or less than the predetermined ratio, and the output speed is 0 or the time rate of change of the output speed is predetermined. If the rate of change is equal to or less than the change rate, it is determined that it is time to tow and start the other vehicle. With this configuration, it is possible to immediately determine whether or not the vehicle is towing another vehicle based on the driver's accelerator operation or the like without using the time integrated values of the vehicle speed, the vehicle acceleration, and the driving force. You. As a result, it is possible to provide a vehicle control method capable of executing a shift control by accurately determining whether or not the vehicle is in a towing state immediately after the start when the own vehicle starts towing another vehicle. it can.
[0038]
In a control method according to a ninth aspect, in addition to the configuration of the eighth aspect, the determining step includes determining that an accelerator opening is equal to or greater than a predetermined opening and a ratio is equal to or less than the predetermined ratio. If there is no brake signal input and the output rotational speed is 0, it is determined that it is time to tow and start the other vehicle.
[0039]
According to the ninth aspect, despite the large accelerator opening, the speed ratio of the torque converter, which is one of the fluid couplings, is small. Based on a first determination that the vehicle is in a towing state and a second determination that the vehicle is stopped due to a high load, it is determined whether or not another vehicle is being towed. Can be done instantly. In particular, since the output speed of the torque converter is used instead of using the vehicle speed of the vehicle, the resolution is high, so that it is possible to accurately and immediately determine whether the vehicle is in the towing state.
[0040]
The control method according to a tenth aspect of the present invention further includes a step of calculating a time rate of change of the output speed in addition to the configuration of the eighth aspect. The determining step determines that the other vehicle is open when the accelerator opening is equal to or greater than the predetermined opening, the ratio is equal to or less than the predetermined ratio, and the time change rate is equal to or less than the predetermined change rate. It includes a step of determining that it is time to start towing.
[0041]
According to the tenth aspect, since the speed ratio of the torque converter, which is one of the fluid couplings, is small despite the large accelerator opening, the first determination that the torque converter is slipping and is in a traction state is made. Based on the second determination that the load is high and the temporal change rate of the output speed of the torque converter is low, it is possible to immediately determine whether or not the vehicle is being towed by another vehicle. In particular, because the time change rate of the output speed of the torque converter is used instead of using the acceleration of the vehicle, the resolution is high, so it is possible to accurately and immediately determine whether or not the vehicle is in the towing state. it can.
[0042]
The control method according to an eleventh aspect of the present invention is the control method according to any one of the eighth to tenth aspects, further comprising: a storage step of storing a shift map of the transmission; If it is determined that there is a shift line, the method further includes a changing step of changing a shift line on the shift map.
[0043]
According to the eleventh aspect, in a high-load state where another vehicle is being pulled, the shift line of the shift map can be changed so that the vehicle can be started quickly.
[0044]
In the control method according to the twelfth aspect, in addition to the configuration of the eleventh aspect, the transmission is an automatic transmission having a planetary gear type reduction mechanism. The changing step includes a step of changing the upshift line on the shift map to a higher speed side.
[0045]
According to the twelfth aspect, in an automatic transmission having a planetary gear type reduction mechanism in a high load state in which another vehicle is being pulled, the upshift shift line from 1st to 2nd in the shift map is changed to a higher speed side. Thus, the starting operation of the vehicle can be promptly performed.
[0046]
In a control method according to a thirteenth aspect, in addition to the configuration of the eighth aspect, the fluid coupling is a torque converter with a lock-up clutch. The control method further includes a step of increasing the lock-up area of the lock-up clutch when it is determined in the determining step that it is a timing to tow and start the other vehicle.
[0047]
According to the thirteenth aspect, in the low speed ratio region of the torque converter, the temperature of the hydraulic oil of the automatic transmission increases, but the lockup region is increased to suppress the increase in the oil temperature while the vehicle travels. Performance can be improved.
[0048]
In a control method according to a fourteenth aspect, in addition to the configuration of the eighth aspect, the driving force source is an engine. The control method further includes a step of setting the opening characteristic of the throttle valve of the engine to a tendency that the opening degree tends to be larger than that in the normal state when it is determined in the determining step that it is the timing to tow and start the other vehicle.
[0049]
According to the fourteenth aspect, the opening degree characteristic of the throttle valve of the engine (the characteristic of the opening degree of the electromagnetic throttle valve with respect to the accelerator opening degree) is changed to an opening degree characteristic such that the opening degree becomes larger than in the normal state. The running performance of the vehicle under a high load can be improved.
[0050]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are the same. Therefore, detailed description thereof will not be repeated.
[0051]
Hereinafter, a power train of a vehicle including a control device according to an embodiment of the present invention will be described. The control device according to the present embodiment is realized by an ECU (Electronic Control Unit) 1000 shown in FIG. In the present embodiment, an automatic transmission having a torque converter with a fluid coupling as an automatic transmission and having a planetary gear type reduction mechanism will be described. The control device according to the present invention is not limited to such a stepped automatic transmission, and may be, for example, a continuously variable transmission.
[0052]
A power train of a vehicle including the control device according to the present embodiment will be described with reference to FIG. ECU 1000, which is a control device according to the present embodiment, includes an engine ECU that controls engine 100, and an ECT (Electronic Controlled Automatic Transmission) _ECU that controls torque converter 200 and automatic transmission 300. It is not essential that the ECU is divided into two ECUs.
[0053]
As shown in FIG. 1, the power train of the vehicle includes an engine 100, a torque converter 200, an automatic transmission 300, and an ECU 1000.
[0054]
The output shaft of engine 100 is connected to the input shaft of torque converter 200.
Engine 100 and torque converter 200 are connected by a rotating shaft. Therefore, the output shaft speed NE (engine speed NE) of the engine 100 detected by the engine speed sensor 400 and the input shaft speed (pump speed) of the torque converter 200 are the same.
[0055]
The torque converter 200 includes a lock-up clutch 210 for directly connecting the input shaft and the output shaft, a pump impeller 220 on the input shaft side, a turbine impeller 230 on the output shaft side, and a one-way clutch 250. And a stator 240 exhibiting an amplification function. Torque converter 200 and automatic transmission 300 are connected by a rotating shaft. The output shaft rotation speed NT (turbine rotation speed NT) of the torque converter 200 is detected by a turbine rotation speed sensor 410. Output shaft speed NOUT of automatic transmission 300 is detected by output shaft speed sensor 420.
[0056]
FIG. 2 shows an operation table of the automatic transmission 300. According to the operation table shown in FIG. 2, the clutch elements (C1 to C4 in the figure), the brake elements (B1 to B4), and the one-way clutch elements (F0 to F3), which are friction elements, are related to which gear stage. It is shown if it is released and released. At the first speed used when the vehicle starts, the clutch element (C1) and the one-way clutch elements (F0, F3) are engaged. Among these clutch elements, the clutch element C1 is particularly called an input clutch 310. The input clutch 310 is also called a forward clutch or a forward clutch, and as shown in the operation table of FIG. 2, the vehicle moves forward except for the parking (P) position, the reverse running (R) position, and the neutral (N) position. Is always used in the engaged state when configuring the gear stage for the vehicle.
[0057]
As described above, ECU 1000 that controls these power trains includes an engine ECU that controls engine 100, and an ECT_ECU that controls torque converter 200 and automatic transmission 300.
[0058]
A signal indicating the turbine speed NT from the turbine speed sensor 410 and a signal indicating the output shaft speed NOUT from the output shaft speed sensor 420 are input to ECT_ECU. Further, a signal indicating the engine speed NE detected by the engine speed sensor 400 and a signal indicating the throttle opening detected by the throttle position sensor are input from the engine ECU to the ECT_ECU.
[0059]
These rotation speed sensors are provided on the input shaft of the torque converter 200, the output shaft of the torque converter 200, and the output shaft of the automatic transmission 300 so as to face the teeth of the rotation detecting gears respectively attached thereto. These rotation speed sensors are sensors capable of detecting slight rotations of the input shaft of the torque converter 200, the output shaft of the torque converter 200, and the output shaft of the automatic transmission 300. This is a sensor using a so-called magnetoresistive element.
[0060]
The ECT_ECU outputs to the automatic transmission 300 a solenoid control signal for engaging or disengaging the clutch element and the brake element shown in FIG.
[0061]
Referring to FIG. 3, a control structure of a program executed in ECU 1000 of the control device according to the present embodiment will be described.
[0062]
In step (hereinafter, step is abbreviated as S) 100, ECU 1000 performs towing determination prerequisite processing for determining whether or not the vehicle is towing a trailer. Specifically, the ECU 1000 determines that the brake signal is OFF, that the position of the automatic transmission 300 is the running position (drive position), that the gear position of the automatic transmission 300 is 1st, that the vehicle speed is Is not less than 0 and less than the threshold value V (1). These confirmations are performed based on a signal input to ECU 1000 or based on information determined by ECT_ECU based on the input signal.
[0063]
In S200, ECU 1000 detects the accelerator opening. In S300, ECU 1000 detects input shaft speed NE (= output shaft speed of engine 100) and output shaft speed NT (turbine speed) of torque converter 200, and detects engine speed NE and turbine speed. The speed ratio e of the torque converter 200 is calculated from the number NT. At this time, the speed ratio e is calculated as follows: speed ratio e = turbine rotational speed NT / engine rotational speed NE. The engine speed NE is detected from the engine speed sensor 400, and the turbine speed NT is detected based on a signal input from the turbine speed sensor 410 to the ECU 1000.
[0064]
In S400, ECU 1000 determines that the accelerator opening detected in S200 is greater than or equal to a predetermined accelerator opening threshold θ (1), and that speed ratio e of torque converter 200 is predetermined. It is determined whether or not the speed ratio is equal to or less than a threshold value e (1). If the accelerator opening is equal to or larger than threshold value θ (1) and speed ratio e of torque converter 200 is equal to or smaller than threshold value e (1) (YES in S400), the processing is terminated. Moved to S500. If not (NO in S400), this process ends.
[0065]
In S500, ECU 1000 detects output shaft rotation speed NOUT of automatic transmission 300, and calculates output shaft rotation speed change ΔNOUT per unit time of output shaft rotation speed NOUT. At this time, for example, the difference between the output shaft rotation speed NOUT of the automatic transmission 300 detected one sampling time before and the output shaft rotation speed NOUT detected this time is calculated as the output shaft rotation speed change ΔNOUT, or is determined in advance. The change of the output shaft rotation speed NOUT per time (for example, 100 msec) may be calculated as the output shaft rotation speed change ΔNOUT. The output shaft speed NOUT of the automatic transmission 300 is detected based on a signal input from the output shaft speed sensor 420 to the ECU 1000.
[0066]
In S600, ECU 1000 determines whether output shaft rotation speed NOUT of automatic transmission 300 is 0 (NOUT = 0) or output shaft rotation speed change ΔNOUT is greater than 0 and a predetermined output shaft rotation speed change. It is determined whether or not the threshold value is equal to or less than ΔNOUT (1) (0 <ΔNOUT ≦ ΔNOUT (1)). If output shaft rotation speed NOUT = 0 or output shaft rotation speed change ΔNOUT is 0 <ΔNOUT ≦ ΔNOUT (1) (YES in S600), the process proceeds to S700. If not (NO in S600), this process ends.
[0067]
In S700, ECU 1000 determines, as towing determination processing, the timing at which the vehicle starts towing by starting a trailer or the like. When it is determined in this manner, the upshift line from the first to the second in the shift map of the automatic transmission 300 is changed to the high speed side, the lockup region of the lockup clutch is increased, and the throttle valve of the engine 100 is changed. The opening degree characteristic is changed to an opening degree characteristic such that the opening degree becomes larger than that in the normal state. By performing such a process, the timing of shifting from 1st to 2nd is delayed, the rotation speed of engine 1000 increases, the output of engine 100 increases, transmission loss in torque converter 200 is suppressed, or the same. Even with the accelerator opening, the output of the engine 100 is increased by increasing the opening of the electromagnetic throttle valve. As a result, the starting vehicle performance during towing can be improved.
[0068]
The processing from S100 to S700 is repeatedly performed at a predetermined sampling interval (for example, a time interval determined by the operating frequency of ECU 1000).
[0069]
The operation of the vehicle equipped with ECU 100 according to the present embodiment based on the above structure and flowchart will be described. It is assumed that this vehicle is towing a trailer.
[0070]
ECU 1000 performs the towing determination prerequisite process at a predetermined sampling time interval, for example, in response to the ignition key being at the ON position. When the driver of the vehicle sets the automatic transmission 300 to the running position, releases the brake pedal and depresses the accelerator pedal, the accelerator opening is detected based on a signal from the accelerator opening sensor (S100). A speed ratio e of the torque converter 200 (= turbine speed NT / engine speed NE) is calculated from the engine speed NE and the turbine speed NT (S300).
[0071]
When the driver depresses the accelerator pedal deeply or largely, the accelerator opening is equal to or larger than the threshold value θ (1), and the speed ratio e is equal to or smaller than the threshold value e (1) (in S400). If (YES), output shaft rotation speed NOUT of automatic transmission 300 is 0 (YES in S600), it is determined that this vehicle detects a trailer.
Further, even if time change rate ΔNOUT of output shaft rotation speed NOUT of automatic transmission 300 is greater than 0 and equal to or smaller than threshold value ΔNOUT (1) (YES in S600), it is determined that this vehicle detects a trailer. Is determined.
[0072]
In any case, immediately after the start of the vehicle, it can be immediately determined whether or not the vehicle is towing a trailer. When it is determined in this way, for example, the shift timing of the upshift from 1st to 2nd is shifted to the higher speed side. At this time, as shown in FIG. 4, the normal turbine speed NT when the trailer is not towed is represented by a dotted line, and the turbine speed NT before changing the shift timing during towing is represented by a one-dot chain line. That is, the turbine speed NT after changing the shift timing during towing is indicated by a solid line. The output shaft rotation speed NOUT of the automatic transmission 300 which is comparable to that in the normal state can be realized by increasing the rotation speed of the engine 100 by increasing the rotation speed of the engine 100 to increase the engine output to cope with the high load state. .
[0073]
As described above, according to the ECU according to the present embodiment, the accelerator opening, the speed ratio calculated based on the input rotation speed and the output rotation speed of the torque converter, and the output rotation speed of the automatic transmission are Based on this, it can be determined whether or not it is time to tow and start another vehicle. In other words, despite the driver not stepping on the brake and depressing the accelerator greatly and the accelerator opening is equal to or greater than the predetermined opening, the torque converter slips due to the high load and the speed ratio increases. Otherwise, if the output speed of the automatic transmission is 0 or the time rate of change of the output speed of the automatic transmission is equal to or less than a predetermined change rate, the timing at which the other vehicle is towed and started is pulled. It is immediately determined that there is, and the engine output can be increased or the torque converter can be locked up to respond to a high load immediately. As a result, when the host vehicle starts towing the other vehicle, the shift control can be executed by accurately determining whether or not the vehicle is in the towing state immediately after the start.
[0074]
If the vehicle is a four-wheel drive vehicle and is equipped with a subtransmission, the subtransmission may be shifted to Lo when it is determined that the trailer is being pulled.
[0075]
In addition to shifting control, not only when starting up, but also on downhill roads, when pulling the trailer, change the downshift line to a higher speed side than normal and activate the lockup at the time of deceleration, and an appropriate engine You may make it implement | achieve a brake.
[0076]
The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a control block diagram of an automatic transmission according to an embodiment of the present invention.
FIG. 2 is an operation table of the automatic transmission shown in FIG.
FIG. 3 is a diagram showing a control structure of a program of a towing determination process executed by an ECU.
FIG. 4 is a timing chart showing an operation of a vehicle equipped with the automatic transmission according to the embodiment of the present invention.
[Explanation of symbols]
100 engine, 200 torque converter, 210 lock-up clutch, 220 pump impeller, 230 turbine impeller, 240 stator, 250 one-way clutch, 300 automatic transmission, 310 input clutch, 400 engine speed sensor, 410 turbine speed sensor, 420 Output shaft speed sensor, 1000 ECU.

Claims (14)

A driving force source, a control device for a vehicle equipped with a fluid coupling that transmits a driving force from the driving force source to a transmission, wherein the vehicle may tow another vehicle,
First detection means for detecting an accelerator opening by a driver of the vehicle;
Second detection means for detecting the input rotation speed and the output rotation speed of the fluid coupling,
Calculation means for calculating the ratio of the output rotation speed to the input rotation speed of the fluid coupling,
A control device for a vehicle, comprising: a determination unit configured to determine a timing for towing and starting the other vehicle based on the accelerator opening, the ratio, the output rotation speed, and the brake signal. . The determination means is configured such that the accelerator opening is equal to or greater than a predetermined opening, the ratio is equal to or less than a predetermined ratio, no brake signal is input, and the output rotation speed is zero. The vehicle control device according to claim 1, further comprising a unit configured to determine that it is time to tow and start the other vehicle. The control device further includes means for calculating a time rate of change of the output rotation speed,
The determining means may be configured such that the accelerator opening is equal to or greater than a predetermined opening, the ratio is equal to or less than a predetermined ratio, and the time change rate is equal to or less than a predetermined change rate. The vehicle control device according to claim 1, further comprising means for determining that it is a timing to tow and start the other vehicle. The control device includes:
Storage means for storing a shift map of the transmission;
4. The vehicle according to claim 1, further comprising: a change unit configured to change a shift line on the shift map when the determination unit determines that the timing for starting the vehicle by pulling the other vehicle has been reached. 5. The control device for a vehicle according to any one of the preceding claims. The transmission is an automatic transmission having a planetary gear type reduction mechanism,
The control device for a vehicle according to claim 4, wherein the change unit includes a unit configured to change an upshift line on the shift map to a higher speed side. The fluid coupling is a torque converter with a lock-up clutch,
6. The control device according to claim 1, further comprising: a unit for increasing a lock-up area of the lock-up clutch when it is determined by the determination unit that it is a timing for towing and starting the other vehicle. 7. A control device for a vehicle according to any one of the above. The driving force source is an engine,
The control device may cause the opening characteristic of the throttle valve of the engine to tend to be larger than in a normal state when it is determined that the timing to start the vehicle by towing the other vehicle by the determining unit. The control device for a vehicle according to any one of claims 1 to 6, further comprising: A driving force source, a control method for a vehicle equipped with a fluid coupling that transmits a driving force from the driving force source to a transmission, wherein the vehicle may tow another vehicle,
A first detection step of detecting an accelerator opening by a driver of the vehicle;
A second detection step of detecting an input rotation speed and an output rotation speed of the fluid coupling;
A calculating step of calculating a ratio of the output rotation speed to the input rotation speed of the fluid coupling,
A control method for a vehicle, comprising: a determination step of determining, based on the accelerator opening, the ratio, the output rotation speed, and a brake signal, a timing for towing and starting the other vehicle. In the determining step, the accelerator opening is equal to or greater than a predetermined opening, the ratio is equal to or less than a predetermined ratio, no brake signal is input, and the output rotational speed is 0. 9. The vehicle control method according to claim 8, further comprising a step of determining that it is time to tow and start the other vehicle. The control method further includes a step of calculating a time rate of change of the output rotation speed,
In the determining step, the accelerator opening is equal to or more than a predetermined opening, the ratio is equal to or less than a predetermined ratio, and the time change rate is equal to or less than a predetermined change rate. 9. The vehicle control method according to claim 8, further comprising a step of determining that it is a timing to tow and start the other vehicle. The control method includes:
A storage step of storing a shift map of the transmission;
The method according to any one of claims 8 to 10, further comprising a changing step of changing a shift line on the shift map when it is determined in the determining step that it is a timing to tow and start the other vehicle. Vehicle control method. The transmission is an automatic transmission having a planetary gear type reduction mechanism,
12. The vehicle control method according to claim 11, wherein the changing step includes changing an upshift line on the shift map to a higher speed side. The fluid coupling is a torque converter with a lock-up clutch,
13. The control method according to claim 8, wherein the control method further includes a step of increasing a lock-up area of the lock-up clutch when it is determined in the determining step that it is a timing to tow and start the other vehicle. A vehicle control method according to any one of the above. The driving force source is an engine,
In the control method, when it is determined in the determining step that it is the timing to start the vehicle by towing the other vehicle, the opening characteristic of the throttle valve of the engine tends to be larger than in a normal state. The vehicle control method according to claim 8, further comprising:

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