JP2017223324A - Control device of continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a continuously variable transmission capable of generating engine brake desired by a driver according to a running state in downhill running.SOLUTION: A control device 1 of a continuously variable transmission includes running state acquiring means 10a for acquiring a running state in downhill running, downhill transmission gear ratio control portion 10b for controlling gear shift to a transmission gear ratio at a low speed side on the basis of a target deceleration in downhill running, an engine brake shortage determination portion 10c for determining whether engine brake is insufficient or not, engine brake excessiveness determination means 10d for determining whether the engine brake is excessive or not, and a learning portion 10e for setting a learning value of a target deceleration larger than a target deceleration used in controlling the downhill transmission gear ratio when the shortage is determined, and setting a learning value of a target deceleration smaller than the target deceleration used in controlling the downhill transmission gear ratio when the excessiveness is determined, and the learning portion 10e sets the learning value of the target deceleration in every running state.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for a continuously variable transmission that performs gear shift control to a low speed gear ratio in order to generate engine braking when traveling downhill.

  2. Description of the Related Art In recent years, continuously variable transmissions (CVTs) that can change a gear ratio steplessly without a shift shock have been widely put into practical use as automatic transmissions for vehicles. The continuously variable transmission includes a primary pulley provided on an input shaft, a secondary pulley provided on an output shaft, and a power transmission element such as a chain spanned between these pulleys. The gear ratio is continuously changed by changing the winding diameter of the power transmission element.

  The control device for controlling the continuously variable transmission controls the gear ratio according to the driving state of the vehicle such as the accelerator opening and the vehicle speed. In this gear ratio control, for example, the target primary pulley speed (hereinafter referred to as “primary speed”) is set according to the operating state, and the actual primary speed converges to the target primary speed. Control to do.

  The control device for the continuously variable transmission performs control to change to a low speed (low side) gear ratio in order to cause the vehicle to generate an engine brake while the vehicle is traveling on a downhill road. This control is hereinafter referred to as “downhill gear ratio control”. In this downhill gear ratio control, for example, a target deceleration is set so that the vehicle travels at a constant deceleration on a downhill road, and the target primary is set according to the road gradient, the vehicle speed, etc. so as to achieve this target deceleration. Set the rotation speed.

  By the way, the driver has a preference for engine braking on downhill roads. For example, there are drivers who want to drive downhill roads with little engine brake applied, and there are drivers who want to drive downhill roads with strong engine brakes applied. Therefore, when downhill gear ratio control is uniformly performed using a uniform target deceleration, some drivers feel that the engine brake is excessive or insufficient, and the driving feeling is reduced. There is a fear.

  Therefore, it is desired to generate an engine brake according to the driver's preference. For example, in Patent Document 1, when the gear ratio control is performed so that the target acceleration (corresponding to the target deceleration) is obtained when traveling on a downhill road, it is determined whether the driver is excessive or insufficient with respect to the engine brake. Based on the above, it is disclosed that the target acceleration is learned and corrected. In this learning correction, when it is determined that the engine brake is excessive, the target acceleration is corrected to increase, and when it is determined that the engine brake is insufficient, the target acceleration is corrected to decrease.

JP 2001-141048 A

  By the way, during traveling downhill, there are various traveling conditions such as the presence or absence of a forward vehicle. Some drivers may change their engine brake preferences according to such driving conditions. In the technique disclosed in Patent Document 1, target deceleration is learned in accordance with engine brake excess / deficiency, but this learning does not take into account the traveling conditions during downhill traveling. Therefore, the driver may feel that the engine brake generated by the gear ratio control using the target deceleration after learning is insufficient or excessive depending on the driving situation.

  The present invention has been made to solve the above-described problems, and is a control device for a continuously variable transmission capable of generating a driver's favorite engine brake according to a traveling condition during traveling on a downhill road. The purpose is to provide.

  A control device for a continuously variable transmission according to the present invention is a control device for a continuously variable transmission that controls a speed change to a low speed side gear ratio when a vehicle travels on a downhill road, and acquires a traveling state when traveling on the downhill road. A driving condition acquisition means for performing downshift, a downhill transmission ratio control means for controlling the transmission to a low speed side transmission ratio based on the target deceleration when traveling on a downhill road, and a downshifting gear ratio control means for controlling the transmission to a low speed side transmission ratio. The engine brake generated by the gear shift control is determined to be insufficient for the driver, and the engine speed is controlled to the low gear ratio by the downhill gear ratio control means. An engine brake excess determining means for determining whether the engine brake generated in response to the shift control is excessive for the driver, and a downhill gear ratio control means if the engine brake insufficient determining means determines that the engine brake is insufficient. If a deceleration larger than the target deceleration used is set as the learning value for the target deceleration, and the engine braking excess determination means determines that it is excessive, the target deceleration used by the downhill gear ratio control means Learning means for setting a smaller deceleration as a learning value for the target deceleration, and the learning means sets a learning value for the target deceleration for each driving situation acquired by the driving situation acquisition means, To do.

  In the continuously variable transmission control device according to the present invention, when the driver feels that the engine brake is insufficient, a target deceleration (learning value) larger than the target gear ratio used in the downhill gear ratio control is set. When the driver feels that the engine brake is excessive, a target deceleration (learned value) smaller than the target speed ratio used in the downhill speed ratio control is set. In particular, in the control device for a continuously variable transmission according to the present invention, a traveling state during traveling on a downhill road is acquired, and a target deceleration (learned value) is set for each traveling state. In the continuously variable transmission control device according to the present invention, when a target deceleration (learning value) corresponding to a traveling situation during downhill traveling is set, based on the target deceleration (learning value). Shift control is performed to a low speed side gear ratio. Thus, according to the control device for a continuously variable transmission according to the present invention, it is possible to generate a driver's favorite engine brake according to the traveling state during traveling downhill. Since the driver's favorite engine brake is generated in accordance with the traveling condition, the traveling feeling during traveling downhill is improved.

  In the control device for a continuously variable transmission according to the present invention, the learning means preferably has a learning map including one or more parameters for each traveling situation. By preparing the learning map in this way, it is possible to classify the target deceleration (learning value) for each driving situation using this learning map, and this learning map is used when performing downhill gear ratio control. The target deceleration according to the driving situation can be acquired.

  In the control device for a continuously variable transmission according to the present invention, when the learning means sets a learning value for a target deceleration of an arbitrary traveling situation while traveling on a downhill road, the learning means uses the learned value in an arbitrary traveling situation. It is preferable to update only the target deceleration of the learning map. When configured in this way, only the learning map in any driving situation in which learning was actually performed is updated, so only the target deceleration in any driving situation in which learning was actually performed is used for downhill gear ratio control. Can be reflected.

  In the control device for a continuously variable transmission according to the present invention, when the learning means sets a learning value for a target deceleration of an arbitrary traveling situation while traveling on a downhill road, the learning means uses the learned value in an arbitrary traveling situation. It is preferable to update the target deceleration of the learning map and update the target deceleration of the learning map in other travel situations. When configured in this way, the learning map in other driving situations other than the actual driving situation in which learning was actually performed is also updated, so the learning result in any driving situation is used as the target deceleration in other driving situations. Can also be reflected. In particular, even when traveling on a downhill road in a driving situation in which learning is not actually performed, the downhill gear ratio control can be performed using a target deceleration reflecting the driver's preference.

  In the control device for a continuously variable transmission according to the present invention, when the learning means sets a learning value of the target deceleration of an arbitrary traveling situation while traveling on a downhill road, the learning means reflects the degree of reflection in learning rather than the learning value. It is preferable to update the target deceleration of the learning map in other driving situations using the reduced value. By doing so, it is possible to suppress changes in the engine brake generated in the vehicle when traveling on a downhill road in a traveling state where learning is not actually performed.

  In the continuously variable transmission control device according to the present invention, the parameter is preferably the presence or absence of a preceding vehicle. In this way, it is possible to generate a driver's favorite engine brake according to the presence or absence of a forward vehicle traveling on a downhill road.

  In the continuously variable transmission control device according to the present invention, it is preferable that the parameter is whether or not the winding road. In this way, it is possible to generate a driver's favorite engine brake according to whether or not the winding road is traveling on a downhill road.

  In the continuously variable transmission control device according to the present invention, the parameter is preferably a road gradient. By doing so, it is possible to generate a driver's favorite engine brake corresponding to the magnitude of the road gradient during traveling downhill.

  In the control device for a continuously variable transmission according to the present invention, the parameter is preferably a vehicle speed. In this way, it is possible to generate a driver's favorite engine brake according to the level of the vehicle speed while traveling downhill.

  In the continuously variable transmission control device according to the present invention, when the learning means sets the learning value of the target deceleration while traveling on an arbitrary downhill road, the learning value of the set target deceleration is set to the arbitrary downhill road. It is preferable to permit use in the downhill gear ratio control means from the next downhill road traveling. By doing in this way, the change of the deceleration (engine brake) during traveling downhill can be avoided, and the driver does not feel uncomfortable.

  In the continuously variable transmission control device according to the present invention, the learning means sets at least one of the uphill traveling, the flat road traveling, and the stop after setting the learning value of the target deceleration while traveling on any downhill road. It is preferable to permit the use of the learning value of the target deceleration after performing the above for a predetermined time. By doing so, it is possible to accurately determine whether or not the learned downhill road has been completed, and it is possible to reliably reflect the target deceleration (learned value) from the next downhill road travel.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to generate | occur | produce a driver | operator's favorite engine brake according to the driving | running | working condition in the downhill road driving | running | working.

It is a block diagram which shows the structure of the control apparatus of the continuously variable transmission which concerns on embodiment. An example of the learning map which concerns on embodiment is shown, (a) is a learning map which combined road gradient and vehicle speed other than a front vehicle absence and a winding road, (b) is a front vehicle absence, a winding road, a road gradient, and a vehicle speed. (C) is a learning map combining road gradient and vehicle speed other than the presence of the forward vehicle and the winding road, and (d) is a combination of road gradient and the vehicle speed of the forward vehicle and the winding road. It is a learning map. It is a main flowchart concerning an embodiment. It is a flowchart of engine brake shortage determination concerning an embodiment. It is a flowchart of the engine brake excess determination which concerns on embodiment. It is a flowchart of learning value reflection / update which concerns on embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  In the embodiment, the control device for a continuously variable transmission is applied to a control device 1 of a chain type continuously variable transmission (CVT (Continuously Variable Transmission)). A control device 1 for a continuously variable transmission according to an embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a control device 1 for a continuously variable transmission according to an embodiment.

  Before describing the control device 1, the engine 2 and the continuously variable transmission 3 will be described. First, the engine 2 will be described. The engine 2 may be of any type, but is, for example, a horizontally opposed four-cylinder gasoline engine. A continuously variable transmission 3 is connected to the crankshaft (output shaft) 2 a of the engine 2. The engine 2 is controlled by an engine control unit (hereinafter referred to as “ECU (Engine Control Unit)”) 20.

  The ECU 20 is a control device that comprehensively controls the engine 2. The ECU 20 includes a microprocessor that performs calculations, a ROM that stores programs for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, an EEPROM, an input / output I / F, and the like. Has been.

  Various sensors such as a crank angle sensor 21 and an accelerator pedal sensor 22 are connected to the ECU 20 in order to acquire information necessary for control. The crank angle sensor 21 detects the rotation angle of the crankshaft 2 a of the engine 2. The ECU 20 includes a processing unit that calculates the engine speed from the rotation angle of the crankshaft 2a. The accelerator pedal sensor 22 detects the amount of depression of an accelerator pedal (not shown) (accelerator pedal opening (hereinafter referred to as “accelerator opening”)).

  Next, the continuously variable transmission 3 will be described. The continuously variable transmission 3 converts the driving force from the engine 2 and outputs it. The continuously variable transmission 3 includes a torque converter 30 and a forward / reverse switching mechanism 31. The continuously variable transmission 3 includes a primary shaft 32 connected to the crankshaft 2 a of the engine 2 via the torque converter 30 and the forward / reverse switching mechanism 31, and a secondary shaft 33 disposed in parallel with the primary shaft 32. And. The torque converter 30 has a clutch function and a torque amplification function. The forward / reverse switching mechanism 31 has a function of switching between normal rotation and reverse rotation (forward and reverse of the vehicle) of the drive wheels.

  A primary pulley 34 is provided on the primary shaft 32. The primary pulley 34 has a fixed pulley 34a and a movable pulley 34b. The fixed pulley 34 a is joined to the primary shaft 32. The movable pulley 34b faces the fixed pulley 34a, and is mounted so as to be slidable in the axial direction of the primary shaft 32 and not relatively rotatable. The primary pulley 34 is configured to be able to change a cone surface interval (that is, pulley groove width) between the fixed pulley 34a and the movable pulley 34b.

  A secondary pulley 35 is provided on the secondary shaft 33. The secondary pulley 35 has a fixed pulley 35a and a movable pulley 35b. The fixed pulley 35 a is joined to the secondary shaft 33. The movable pulley 35b faces the fixed pulley 35a, and is mounted so as to be slidable in the axial direction of the secondary shaft 33 and not relatively rotatable. The secondary pulley 35 is configured to change the pulley groove width between the fixed pulley 35a and the movable pulley 35b.

  Between the primary pulley 34 and the secondary pulley 35, a chain 36 for transmitting a driving force is suspended. The continuously variable transmission 3 changes the pulley groove width of the primary pulley 34 and the secondary pulley 35 to change the ratio of the winding diameter of the chain 36 to the pulleys 34, 35 (pulley ratio), thereby changing the gear ratio. Change in stages. The gear ratio i is represented by i = Rs / Rp, where Rp is the winding diameter of the chain 36 around the primary pulley 34 and Rs is the winding diameter of the secondary pulley 35.

  A primary drive oil chamber (hydraulic cylinder chamber) 34 c is formed in the movable pulley 34 b of the primary pulley 34. A secondary drive oil chamber (hydraulic cylinder chamber) 35 c is formed in the movable pulley 35 b of the secondary pulley 35. The primary drive oil chamber 34c is introduced with a transmission pressure for changing the pulley ratio (transmission ratio) and a clamping pressure for preventing the chain 36 from slipping. A clamp pressure is introduced into the secondary drive oil chamber 35c.

  Hydraulic pressure (shift pressure and clamp pressure) for shifting the continuously variable transmission 3 is supplied by the valve body 40. A control valve mechanism (not shown) is incorporated in the valve body 40. The control valve mechanism, for example, opens and closes an oil passage formed in the valve body 40 using a plurality of spool valves and a solenoid valve that moves the spool valves, thereby allowing hydraulic pressure (not shown) discharged from an oil pump (not shown). The hydraulic pressures with regulated line pressure are supplied to the primary hydraulic chamber 34c and the secondary hydraulic chamber 35c. The control valve mechanism also supplies the regulated hydraulic pressure to, for example, the forward / reverse switching mechanism 31.

  The continuously variable transmission 3 has an automatic transmission mode, a manual transmission mode, and a temporary manual mode (temporary manual transmission mode). The automatic shift mode is a mode in which the shift stage is automatically downshifted or upshifted according to the traveling state of the vehicle. The manual shift mode is a mode in which the shift stage is downshifted or upshifted according to a shift operation by the driver. The temporary manual mode is a mode in which the shift stage is temporarily downshifted or upshifted according to a shift operation by the driver until a release condition is satisfied during the automatic shift mode.

  A shift lever (select lever) 50 is provided on the floor (center console) of the vehicle. In the shift lever 50, for example, a drive range (D range), a manual range (M range), a parking range (P range), a reverse range (R range), and a neutral range (N range) can be selectively switched. When the drive range is selected by the shift lever 50, the mode is switched to the automatic transmission mode, and when the manual range is selected, the mode is switched to the manual transmission mode. The shift lever 50 is provided with a range switch 51. The range switch 51 is connected to move in conjunction with the shift lever 50 and detects the selected position of the shift lever 50.

  Further, a minus (−) paddle switch 53 and a plus (+) paddle switch 54 are provided on the rear side of the steering wheel 52. The continuously variable transmission 3 switches to the temporary manual mode when the minus paddle switch 53 or the plus paddle switch 54 is operated during the automatic transmission mode. The minus paddle switch 53 is a switch for downshifting the gear position in the manual shift mode or the temporary manual mode. The plus paddle switch 54 is a switch for upshifting the gear position in the manual shift mode or the temporary manual mode.

  Now, the control device 1 of the continuously variable transmission 3 will be described. The control device 1 is a control device that comprehensively controls the continuously variable transmission 3. In particular, the control device 1 according to the present embodiment has a function of performing speed change control (downhill speed ratio control) to a low speed side gear ratio so that the vehicle has a predetermined target deceleration while traveling on a downhill road. Yes. Furthermore, the control device 1 according to the present embodiment has a function of learning so that the target deceleration used in the descending slope speed ratio control becomes the driver's favorite deceleration (and hence engine braking) according to the driving situation. Have.

  An engine brake is generated in the vehicle by controlling the vehicle to have a predetermined deceleration by the downhill gear ratio control described above. Depending on the driver, the engine brake may feel excessive or insufficient. Therefore, the control device 1 learns the target deceleration in order to generate the driver's favorite engine brake. In particular, some drivers may change their engine brake preferences depending on the driving situation. Therefore, the control device 1 learns the target deceleration for each traveling situation. In the present embodiment, the parameters that affect the driver's preference for engine braking in downhill driving use the presence / absence of a preceding vehicle, whether or not a winding road, road gradient (inclination angle of downhill road), and vehicle speed. The driving situation is classified by combining two parameters.

  Each control of the control device 1 is performed by a TCU (Transmission Control Unit) 10. Similar to the ECU 20, the TCU 10 includes a microprocessor, a ROM, a RAM, an EEPROM, an input / output I / F, and the like.

  Various sensors such as a primary pulley rotation sensor 11 and an output shaft rotation sensor 12 are connected to the TCU 10 in order to acquire information necessary for control. In addition, various switches such as a range switch 51, a minus paddle switch 53, and a plus paddle switch 54 are connected to the TCU 10 in order to acquire information necessary for control. Further, the TCU 10 receives various information such as an accelerator opening degree and an engine speed from the ECU 20 via a CAN (Controller Area Network) 60.

  The primary pulley rotation sensor 11 detects the rotation speed of the primary pulley 34. The output shaft rotation sensor 12 detects the rotation speed of the output shaft (secondary shaft 33). In the TCU 10, the vehicle speed is calculated from the rotational speed of the output shaft. The vehicle speed may be, for example, a vehicle speed (vehicle speed) calculated from a wheel speed detected by a wheel speed sensor provided on each wheel. For example, the TCU 10 receives this vehicle speed via the CAN 60.

  Further, the TCU 10 receives information on the preceding vehicle from an image processing unit (hereinafter referred to as “IPU (Image Processing Unit)”) 70 via the CAN 60. The IPU 70 receives left and right image information picked up by the stereo camera unit 71, and uses the left and right image information to perform detection processing of a forward vehicle ahead of the host vehicle, a running lane, and the like.

  Further, the TCU 10 is connected to a vehicle dynamics control unit (hereinafter referred to as “VDCU (Vehicle Dynamics Control Unit)”) 80 via a CAN 60 from a brake pedal (not shown) on / off information, brake hydraulic pressure, lateral acceleration. Receive various information. Various sensors such as a brake switch 81, a brake fluid pressure sensor 82, and a lateral acceleration sensor 83 are connected to the VDCU 80.

  Further, the TCU 10 receives various information such as a steering angle from an electric power steering control unit (hereinafter referred to as “EPSCU (Electric Power Steering Control Unit)”) 90 via the CAN 60. Various sensors such as a steering angle sensor 91 are connected to the EPSCU 90.

  In the automatic transmission mode, the TCU 10 performs control to automatically change the transmission ratio according to the driving state of the vehicle according to the transmission map. In this control, for example, a target value of the primary rotational speed is set so that a predetermined gear ratio is obtained, and the actual primary rotational speed (the primary rotational speed detected by the primary pulley rotational sensor 11) becomes the target primary rotational speed. Thus, by controlling each solenoid valve of the valve body 40, a transmission pressure is generated and the transmission ratio is changed. The shift map is stored in the ROM in the TCU 10.

  In particular, the TCU 10 has a function of performing shift control to a low speed side gear ratio so as to achieve a predetermined target deceleration while traveling downhill. Further, the TCU 10 has a function of learning this target deceleration. In order to realize these functions, the TCU 10 includes a traveling state acquisition unit 10a (corresponding to the traveling state acquisition unit described in the claims) and a downhill transmission ratio control unit 10b (downhills described in the claims). A gear ratio control means), an engine brake shortage determination unit 10c (corresponding to the engine brake shortage determination means described in the claims), and an engine brake excess determination unit 10d (engine brake excessiveness described in the claims). And a learning unit 10e (corresponding to the learning means described in the claims). In the TCU 10, these units 10a to 10e are configured by a program stored in a ROM being executed by a microprocessor. A learning map for target deceleration is stored in the EEPROM of the TCU 10.

  An example of the learning map for target deceleration will be described with reference to FIG. In the present embodiment, the TCU 10 uses the four learning maps M1, M2, M3, and M4 that combine the above-described four parameters (presence / absence of a preceding vehicle, whether or not a winding road, road gradient, and vehicle speed) to change downhill. Perform ratio control and learning. The learning map M1 is a learning map in a driving situation in which each road gradient and each vehicle speed are combined when there is no forward vehicle and when the road is not a winding road (for example, a straight road). The learning map M2 is a learning map in a driving situation in which each road gradient and each vehicle speed are combined when there is no forward vehicle and the winding road. The learning map M3 is a learning map in a traveling situation in which each road gradient and each vehicle speed are combined when there is a forward vehicle and the vehicle is not a winding road. The learning map M4 is a learning map in a traveling situation in which each road gradient and each vehicle speed are combined when there is a forward vehicle and a winding road.

  In the example shown in FIG. 2, the road gradient is divided into three stages: a large gradient, a medium gradient, and a small gradient. The vehicle speed is divided into three stages: high vehicle speed, medium vehicle speed, and low vehicle speed. Therefore, in the example shown in FIG. 2, each of the learning maps M1 to M4 has the target decelerations for nine driving situations that combine the three-stage road gradient and the three-stage vehicle speed. The road gradient and the vehicle speed may be divided in two steps, or four or more steps. An initial value of an arbitrary target deceleration is written in each of the learning maps M1 to M4 when the vehicle is shipped. This target deceleration (initial value) is determined by adaptation.

  The traveling state acquisition unit 10a will be described. The traveling state acquisition unit 10a acquires a traveling state on a downhill road. Specifically, the traveling state acquisition unit 10a determines whether the road is a downhill road based on the road gradient. The road gradient may be obtained, for example, by a well-known arithmetic expression using the vehicle speed and the longitudinal acceleration, may be detected using an inclination sensor, or may be information using a car navigation system. Good.

  When it determines with a downhill road, the driving condition acquisition part 10a determines whether a front vehicle exists ahead of the own vehicle using the information of a front vehicle. In addition, the traveling state acquisition unit 10a determines whether the downhill road is a winding road. Whether or not it is a winding road is determined as a winding road when the steering angle is equal to or greater than a predetermined angle and the lateral acceleration is equal to or greater than a predetermined acceleration, for example, using the steering angle and the lateral acceleration. The predetermined angle and the predetermined acceleration are determined by adaptation. Moreover, you may determine whether it is a winding road using the information of a navigation system, for example. The traveling state acquisition unit 10a uses the road gradient (large gradient, medium gradient, small gradient) and vehicle speed (high vehicle speed, medium vehicle speed, low vehicle speed) in addition to the determined presence / absence of the preceding vehicle and the winding road. Identifies the driving situation while driving downhill.

  The downhill road speed ratio control unit 10b will be described. The downhill gear ratio control unit 10b selects a target deceleration in accordance with the traveling condition while traveling on the downhill road, and performs speed control to the low speed side gear ratio so as to be the target deceleration. When it is determined by the traveling state acquisition unit 10a that there is no forward vehicle and there is no winding road, the downhill road speed ratio control unit 10b selects the learning map M1. When the traveling state acquisition unit 10a determines that there is no forward vehicle and a winding road, the downhill road speed ratio control unit 10b selects the learning map M2. When the traveling state acquisition unit 10a determines that there is a vehicle ahead and there is no winding road, the downhill speed ratio control unit 10b selects the learning map M3. When the traveling state acquisition unit 10a determines that there is a vehicle ahead and a winding road, the downhill gear ratio control unit 10b selects the learning map M4. The downhill gear ratio control unit 10b extracts a target deceleration corresponding to the combination of the vehicle speed and the road gradient from the selected learning map. The downhill gear ratio control unit 10b obtains the target gear ratio (target primary rotation speed) according to the road gradient, the vehicle speed, and the like so as to obtain the extracted target deceleration. Then, the downhill gear ratio control unit 10b controls the valve body 40 so as to achieve the target primary rotation speed.

  Note that the downhill gear ratio control unit 10b basically does not change the learning map (and thus the target deceleration extracted from the learning map) selected once while traveling on the same downhill road. However, when the driving situation changes while traveling on a downhill road (for example, a downhill road longer than a predetermined distance) (for example, when there is no preceding vehicle, or when it becomes a winding road in the middle of a downhill road) The downhill gear ratio control unit 10b may change the learning map (and thus the target deceleration) even when traveling on the same downhill road. In this case, if the target deceleration before the change and the target deceleration after the change are different, in order to suppress sudden changes in vehicle behavior (deceleration, engine brake, etc.), after the change from the target deceleration before the change. It is preferable that the target deceleration is gradually changed.

  Moreover, even if the learning value of the target deceleration is newly set by the learning unit 10e while traveling on the downhill road, the downhill transmission ratio control unit 10b uses the newly set target deceleration (learned value). The target deceleration (learned value) newly set from the time of traveling on the next downhill road after the end of traveling on the downhill road cannot be used.

  The engine brake shortage determination unit 10c will be described. The engine brake insufficiency determining unit 10c determines whether or not there is a driver's insufficiency for the engine brake generated in response to the downhill gear ratio control. Specifically, when the downhill speed ratio control unit 10b performs the speed control to the low speed side gear ratio, the engine brake shortage determination unit 10c uses the information of the brake switch 81 to determine whether or not the brake switch 81 is turned on. Determine whether. When it is determined that the brake switch 81 is on, the engine brake shortage determination unit 10c measures the time during which the brake switch 81 is on. The engine brake shortage determination unit 10c determines whether the measured time is equal to or greater than the first time threshold and equal to or less than the second time threshold. When it is determined that the time during which the brake switch 81 is on is greater than or equal to the first time threshold and less than or equal to the second time threshold (when the brake pedal is operated for a predetermined time), the engine brake shortage determination unit 10c It is determined whether or not the pressure threshold is exceeded. When it is determined that the brake fluid pressure is greater than or equal to the fluid pressure threshold, the engine brake shortage determination unit 10c determines whether or not the amount of change in the vehicle deceleration due to the brake operation is greater than or equal to the change amount threshold. The deceleration may be obtained from, for example, a change in the vehicle speed over time, or may be detected using a longitudinal acceleration sensor. The first time threshold value, the second time threshold value, the hydraulic pressure threshold value, and the change amount threshold value are determined by adaptation.

  Further, the engine brake shortage determination unit 10c determines whether or not the minus paddle switch 53 has been operated. When it is determined that the minus paddle switch 53 has been operated (when a downshift is performed), the engine brake shortage determination unit 10c determines whether or not the amount of change in vehicle deceleration due to the downshift is equal to or greater than a change amount threshold.

  The engine brake shortage determination unit 10c determines that the brake switch 81 is turned on and the on-time is longer than the first time threshold and less than the second time threshold, the brake fluid pressure is greater than the fluid pressure threshold, and the amount of change in deceleration changes. When the amount is equal to or greater than the amount threshold, or when the minus paddle switch 53 is operated and the amount of change in deceleration is the amount of change threshold, it is determined that the driver is willing to lack the engine brake generated in the vehicle.

  The engine brake excess determination unit 10d will be described. The engine brake excess determination unit 10d determines whether or not the driver has an excessive intention with respect to the engine brake generated according to the downhill gear ratio control. Specifically, when the downhill gear ratio control unit 10b performs the gear shift control to the low speed side gear ratio, the engine brake excess determination unit 10d determines whether or not the accelerator opening is equal to or greater than the opening threshold. When the accelerator opening is equal to or greater than the opening threshold (when the accelerator pedal is operated), the engine brake excess determination unit 10d determines that the driver has an excessive intention with respect to the engine brake generated in the vehicle. Note that the opening degree threshold is determined in conformity.

  The learning unit 10e will be described. The learning unit 10e learns the desired target deceleration of the driver according to the traveling condition during traveling on the downhill road. Specifically, when the engine brake shortage determination unit 10c determines that the driver is willing to lack engine brake, the learning unit 10e sets the target deceleration used by the downhill gear ratio control unit 10b. A predetermined amount is added, and the target deceleration after the addition is set as a new target deceleration (learning value). When the engine brake excess determination unit 10d determines that the driver is willing to exceed the engine brake, the learning unit 10e subtracts a predetermined amount from the target deceleration used by the downhill gear ratio control unit 10b, The target deceleration after the subtraction is set as a new target deceleration (learning value). The learning unit 10e associates the newly set target deceleration (learned value) with the traveling state during traveling on a downhill road.

  The predetermined amount to be added or subtracted when the learning value is set is determined by adaptation. The predetermined amount may be a constant amount, or may be a variable amount according to a traveling situation (for example, presence or absence of a preceding vehicle, whether or not a winding road). This predetermined amount is preferably a small amount so that the target deceleration (engine brake) does not change greatly during one downhill road learning. By using a small addition amount or subtraction amount with a restriction in this way, it is possible to gradually change the target deceleration (engine brake) to the driver's preference each time the number of learning increases.

  The learning unit 10e basically performs learning only once while traveling on the same downhill road. However, when the traveling state changes while traveling on a downhill road (for example, a downhill road longer than a predetermined distance), the learning unit 10e may perform learning a plurality of times even while traveling on the same downhill road.

  When the learning unit 10e newly sets a target deceleration (learning value) for a driving situation while traveling on an arbitrary downhill road, the newly set target deceleration (learning value) The use in the downhill gear ratio control unit 10b is permitted from the next downhill road running. Therefore, even when the learning unit 10e newly sets a target deceleration (learning value) while traveling on an arbitrary downhill road, the downhill gear ratio control unit 10b newly operates while traveling on the arbitrary downhill road. The set target deceleration (learned value) cannot be used.

  In particular, the learning unit 10e determines whether or not a downhill road has changed to an uphill road using a road gradient. When it is determined that the road is uphill, the learning unit 10e measures the elapsed time since the road is uphill, and determines whether the elapsed time is equal to or greater than the time threshold. Further, the learning unit 10e determines whether or not the road has become a flat road from the downhill road using the road gradient. When it is determined that the road has become a flat road, the learning unit 10e measures the elapsed time since the road has become a flat road, and determines whether the elapsed time is equal to or greater than the time threshold. The learning unit 10e determines whether the vehicle has stopped using the vehicle speed. When it determines with having stopped, the learning part 10e measures the elapsed time after stopping, and determines whether the elapsed time is more than a time threshold value. In the learning unit 10e, when a descending slope road becomes an uphill road, the time threshold or more has elapsed, or when the descending slope road becomes a flat road, the time threshold or more has elapsed, or the vehicle has stopped after traveling downhill and the time threshold or more has elapsed. If this happens, use of the newly set target deceleration (learned value) is permitted.

  The learning unit 10e rewrites the target deceleration of the learning map of the EEPROM when the ignition switch is turned off when the target deceleration (learned value) of an arbitrary driving situation is newly set while the ignition switch is turned on. (Update learning map).

  In particular, when a new target deceleration (learning value) is set for an arbitrary driving situation, the learning unit 10e may rewrite only the target deceleration of the learning map corresponding to the arbitrary driving situation. At this time, when new target decelerations (learned values) are set for a plurality of travel situations while the ignition switch is on, the target deceleration of the learning map corresponding to each travel situation is rewritten.

  When the learning unit 10e sets a new target deceleration (learning value) for an arbitrary driving situation, the learning unit 10e uses the new target deceleration (learning value) to set the learning map target corresponding to the arbitrary driving situation. The deceleration may be rewritten and the target deceleration of the learning map in all or a part of the traveling situation other than the arbitrary traveling situation may be rewritten. When rewriting the target deceleration of the learning map in another driving situation, the target reduction in the other driving situation is performed using the addition amount or subtraction amount as it is when setting a new target deceleration (learning value) for any driving situation. Instead of setting the speed, the target deceleration for other driving situations is set using a corrected addition amount or a corrected subtraction amount obtained by multiplying the addition amount or subtraction amount by a coefficient (for example, a coefficient of 0.5 or less). It is good to. By doing so, the degree of reflection is reduced with respect to the target deceleration of other travel situations that are not actually learned.

  The flow of the downhill gear ratio control function and the target deceleration learning function in the TCU 10 (control device 1) will be described along the flowcharts of FIGS. 3 to 6 with reference to FIGS. FIG. 3 is a main flowchart according to the embodiment. FIG. 4 is a flowchart of engine brake shortage determination according to the embodiment. FIG. 5 is a flowchart of the engine brake excess determination according to the embodiment. FIG. 6 is a flowchart of reflecting / updating learned values according to the embodiment.

  As shown in FIG. 3, the TCU 10 determines whether or not the road is a downhill road (S10). If it is determined that the road is a downhill road in the determination of S10, the TCU 10 obtains the driving situation from the presence / absence of front and rear vehicles traveling on the downhill road, whether the road is a winding road, road gradient, and vehicle speed (S12). Then, the TCU 10 selects a learning map corresponding to the traveling situation, and extracts a target deceleration from the learning map (S14). Further, the TCU 10 sets a target primary rotational speed (target gear ratio) based on the target deceleration, and controls the valve body 40 so as to reach the target primary rotational speed (S14). By this control, the gear ratio is changed to a low speed gear ratio, and an engine brake is generated in the vehicle. In the TCU 10, an engine brake shortage determination is performed (S16).

  When performing the determination of S16, as shown in FIG. 4, the TCU 10 determines whether or not the brake switch 81 is on (S30). If it is determined in S30 that the brake switch 81 is on, the TCU 10 determines whether the time during which the brake switch 81 is on is greater than or equal to the first time threshold and less than or equal to the second time threshold (S32). When it is determined in S32 that the on-time is greater than or equal to the first time threshold and less than or equal to the second time threshold, the TCU 10 determines whether or not the brake fluid pressure is greater than or equal to the fluid pressure threshold (S34). When it is determined in S34 that the brake fluid pressure is equal to or greater than the fluid pressure threshold, the TCU 10 determines whether or not the deceleration change amount is equal to or greater than the change threshold value (S36). If it is determined in S36 that the amount of change in deceleration is greater than or equal to the change amount threshold, the TCU 10 determines that there is an intention to lack engine brake (S42).

  When it is determined that the brake switch 81 is OFF in the determination of S30, or when the ON time is determined to be less than the first time threshold value or over the second time threshold value in the determination of S32, or the brake fluid is determined in the determination of S34. When it is determined that the pressure is less than the hydraulic pressure threshold, or when the change amount of the deceleration is determined to be less than the change amount threshold value, the TCU 10 determines whether or not a downshift operation (operation of the minus paddle switch 53) has been performed. (S38). If it is determined in S38 that the minus paddle switch 53 has been operated, the TCU 10 determines whether or not the amount of change in deceleration is greater than or equal to a change amount threshold value (S40). When it is determined in S40 that the amount of change in deceleration is equal to or greater than the change amount threshold, the TCU 10 determines that there is an intention to lack engine braking (S42). On the other hand, if it is determined in S40 that the amount of change in deceleration is less than the change amount threshold value, or if it is determined in S38 that the negative paddle switch 53 has not been operated, the TCU 10 determines that the engine brake is insufficient. It is determined that there is none (S44).

  Returning to FIG. 3, when it is determined in S16 that the engine brake is insufficient (S42), the TCU 10 adds a predetermined amount to the target deceleration currently used in the downhill shift control to obtain a target subtraction value (learning). Value) is set, and this target deceleration (learned value) is linked to the driving situation (S18). Next, when the vehicle travels on a downhill road in this traveling state, the newly set target subtraction value (learned value) is used in the downhill gear ratio control in S14, so that the target deceleration increases and occurs in the vehicle. The engine brake to be increased. When it is determined in S16 that there is no intention of engine brake shortage (S44), the TCU 10 performs engine brake excess determination (S20).

  When performing the determination of S20, as shown in FIG. 5, in TCU10, it is determined whether an accelerator opening is more than an opening threshold value (S50). If it is determined in S50 that the accelerator opening is equal to or greater than the opening threshold, the TCU 10 determines that there is an excessive intention of engine braking (S52). On the other hand, when it is determined in S50 that the accelerator opening is less than the opening threshold, the TCU 10 determines that there is no intention of excessive engine braking (S54).

  Returning to FIG. 3, if it is determined in S20 that the engine braking excess intention is present (S52), the TCU 10 subtracts a predetermined amount from the target deceleration currently used in the downhill shift control to obtain a target subtraction value (learning). Value) is set, and this target deceleration (learned value) is linked to the driving situation (S22). Next, when the vehicle travels on a downhill road in this traveling state, the newly set target subtraction value (learned value) is used in the downhill gear ratio control in S14, so that the target deceleration becomes small and occurs in the vehicle. The engine brake that performs is reduced. If it is determined in S20 that there is no intention of excessive engine braking (S54), the TCU 10 maintains the target deceleration currently used in downhill road shift control (S24).

  When the target subtraction value (learning value) corresponding to an arbitrary traveling situation is set, as shown in FIG. 6, the TCU 10 determines whether or not the road has changed from a downhill road to an uphill road (S60). If it is determined in S60 that the road is uphill, the TCU 10 determines whether or not a time threshold or more has elapsed since the road is uphill (S62).

  If it is determined in S60 that the road is not an uphill road, or if it is determined in S62 that the time threshold or more has not elapsed, the TCU 10 determines whether the road is a flat road from a downhill road ( S64). If it is determined in S64 that the road has become a flat road, the TCU 10 determines whether or not a time threshold or more has elapsed since the road became flat (S66).

  If it is determined in S64 that the road is not a flat road, or if it is determined in S66 that the time threshold or more has not elapsed, the TCU 10 determines whether or not the vehicle has stopped after traveling downhill (S68). ). If it is determined in S68 that the vehicle has stopped, the TCU 10 determines whether or not a time threshold has elapsed since the vehicle stopped (S70). When it is determined that the vehicle is not stopped in the determination of S68 or when it is determined that the time threshold or more has not elapsed in the determination of S70, the process returns to the determination of S60.

  If it is determined in S62 that the time threshold has elapsed, or if it is determined in S66 that the time threshold has elapsed, or if it is determined in S70 that the time threshold has elapsed, TCU10 responds to the driving situation. Use of the target deceleration (learned value) is permitted (S72). Thereby, the target deceleration (learned value) corresponding to this arbitrary traveling situation can be used in the downhill change ratio control from the next downhill road traveling.

  After that, when the ignition switch is turned off (S74), the TCU 10 uses the target subtraction value (learned value) corresponding to an arbitrary driving situation newly set while the ignition switch is turned on, to attain the EEPROM learning map (at least The learning map corresponding to an arbitrary traveling situation is rewritten (S76). As a result, after the next ignition switch is turned on, the new target deceleration (learned value) is reflected in the learning map.

  According to the control device 1 according to the embodiment, by learning the target deceleration for each traveling situation while traveling on a downhill road, the driver's favorite engine brake corresponding to the traveling situation while traveling on a downhill road is generated. Can do. Since the driver's favorite engine brake is generated in accordance with the traveling condition, the traveling feeling during traveling downhill is improved. As a result, the driver can be prevented from stepping on the brake pedal or the accelerator pedal while traveling downhill.

  According to the control device 1 according to the embodiment, by preparing a learning map in which four parameters are combined, the target deceleration (learning value) for each traveling situation can be classified using this learning map. When the downhill gear ratio control is performed, it is possible to acquire the target deceleration corresponding to the traveling situation using this learning map. According to the control device 1 according to the embodiment, learning is performed for various traveling situations during traveling on a downhill road by using four parameters of the presence / absence of a preceding vehicle, whether or not a winding road, road gradient, and vehicle speed. It can be carried out. In particular, by using the presence / absence of a preceding vehicle as a parameter, it is possible to generate a driver's favorite engine brake according to the presence / absence of a preceding vehicle traveling on a downhill road. Further, by using whether or not the winding road is used as a parameter, it is possible to generate a driver's favorite engine brake according to whether or not the winding road is traveling on a downhill road. Further, by using the road gradient as a parameter, it is possible to generate a driver's favorite engine brake corresponding to the road gradient during traveling on a downhill road. Further, by using the vehicle speed as a parameter, it is possible to generate a driver's favorite engine brake according to the vehicle speed while traveling downhill.

  According to the control device 1 according to the embodiment, in the case of a configuration in which only the learning map corresponding to the arbitrary traveling situation is updated using the newly set target deceleration (learning value) of the arbitrary traveling situation, Only the target deceleration in the learned driving condition can be reflected in the downhill gear ratio control.

  According to the control device 1 according to the embodiment, not only a learning map corresponding to an arbitrary driving situation using a newly set target deceleration (learning value) of an arbitrary driving situation but also learning in another driving situation. In the case of a configuration in which the target deceleration of the map is also updated, the learning result of an arbitrary driving situation can be reflected in the target deceleration of other driving situations. In particular, even when traveling on a downhill road in a driving situation in which learning is not actually performed, the downhill gear ratio control can be performed using a target deceleration reflecting the driver's preference. Furthermore, according to the control device 1 according to the embodiment, the target deceleration of the learning map in other driving situations using a value that is less reflected in learning than the target deceleration (learning value) of any driving situation. By updating, it is possible to suppress changes in the engine brake that occur in the vehicle when traveling downhill in a traveling situation where learning is not actually performed.

  According to the control device 1 according to the embodiment, when the learning value of the target deceleration is set while traveling on an arbitrary downhill road, the learning value of the set target deceleration is set to the next downhill road of the arbitrary downhill road. By permitting the use of the downhill gear ratio control means from traveling, it is possible to avoid a change in deceleration (engine braking) during traveling downhill, and the driver does not feel uncomfortable. Further, according to the control device 1 according to the embodiment, after setting the learning value of the target deceleration, learning the target deceleration after performing at least one of uphill traveling, flat road traveling, and stopping for a predetermined time or more. By permitting the use of the value, it is possible to accurately determine whether or not the learned downhill road has been completed, and the target deceleration (learned value) can be reliably reflected from the next downhill road traveling.

  According to the control device 1 according to the embodiment, the learning map (and thus the target deceleration extracted from the learning map) selected once while traveling on the downhill road is not changed in the downhill gear ratio control. The deceleration (engine brake) does not change and the driver does not feel uncomfortable.

  According to the control device 1 according to the embodiment, by setting a limit on the addition amount and the subtraction amount when a new target deceleration (learning value) is set, the target reduction of the driver's preference every time the number of learning increases. It gradually changes to speed (engine braking), and the vehicle behavior does not change greatly after one learning.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, the present invention is applied to a chain type CVT 3, but can be applied to other CVTs such as a belt type and a toroidal type.

  In the above-described embodiment, the learning map is configured using the four parameters of the presence / absence of the preceding vehicle, whether it is a winding road, road gradient, and vehicle speed as parameters of the driving situation, but the general road / highway, weather-related information (outside temperature , Raindrops, wiper operation, etc.), road surface friction coefficient, lane width and other parameters may be used to construct the learning map, or less than three parameters may be used to construct the learning map. Alternatively, a learning map may be configured using five or more parameters.

  In the above embodiment, the engine brake shortage determination unit 10c determines using the on operation of the brake switch 81, the change in the brake fluid pressure and the deceleration, but the determination may be made using only the on operation of the brake switch 81. The determination may be made using only the ON operation of the brake switch 81 and the brake fluid pressure, or may be made using the ON operation of the brake switch 81 and a change in deceleration. In the above-described embodiment, the engine brake shortage determination unit 10c makes the determination using the operation of the minus paddle switch 53 and the change in deceleration, but the determination may be made using only the operation of the minus paddle switch 53.

  In the above embodiment, the engine brake excess determination unit 10d determines using the accelerator opening, but it may also be determined using changes in the accelerator opening speed or deceleration, or using the operation of the plus paddle switch 54. May be determined.

  In the above embodiment, the learning is applied to the learning of the target deceleration in the downhill gear ratio control in the continuously variable transmission 3, but the same learning is performed for the downshift of the downshift control on the downhill road in the stepped automatic transmission. It can also be applied to vehicle speed learning.

1 control device of continuously variable transmission 3 continuously variable transmission 10TCU
10a Travel status acquisition unit (travel status acquisition means)
10b Downhill gear ratio control unit (downhill gear ratio control means)
10c Engine brake shortage determination unit (engine brake shortage determination means)
10d Engine brake excess determination unit (engine brake excess determination means)
10e Learning part (learning means)

Claims (11)

A control device for a continuously variable transmission that shifts to a low speed gear ratio when the vehicle travels on a downhill road,
A traveling condition acquisition means for acquiring a traveling condition during traveling on the downhill road;
Downhill gear ratio control means for performing gearshift control to a low speed side gear ratio based on the target deceleration when traveling on the downhill road;
An engine brake shortage determining means for determining whether or not the engine brake generated in response to the shift control is insufficient for the driver when the downhill speed ratio control means is performing the speed control to the low speed side gear ratio;
An engine brake excess determining means for determining whether or not the engine brake generated in response to the shift control is excessive for the driver when the downhill gear ratio control means is performing the shift control to the low speed side gear ratio;
If the engine brake shortage determining means determines that the engine is insufficient, a deceleration larger than the target deceleration used by the downhill gear ratio control means is set as a learning value for the target deceleration, and the engine brake Learning means for setting a deceleration smaller than the target deceleration used in the downhill gear ratio control means as a learning value for the target deceleration when the excess determination means determines that the excess;
With
The control device for a continuously variable transmission, wherein the learning means sets a learning value of the target deceleration for each traveling situation acquired by the traveling situation acquisition means.   2. The continuously variable transmission control device according to claim 1, wherein the learning unit has a learning map including one or more parameters for each of the travel situations.   When the learning means sets the learning value of the target deceleration for an arbitrary driving situation while traveling on the downhill road, the learning means updates only the target deceleration of the learning map in the arbitrary driving situation using the learning value. The control device for a continuously variable transmission according to claim 2.   When the learning means sets the learning value of the target deceleration of an arbitrary traveling situation while traveling on the downhill road, the learning means updates the target deceleration of the learning map in the arbitrary traveling situation using the learned value. The control device for a continuously variable transmission according to claim 2, wherein the target deceleration of the learning map in another driving situation is also updated.   When the learning means sets a learning value of the target deceleration for an arbitrary driving situation during traveling on the downhill road, the learning means uses the value that is less reflected in learning than the learning value. 5. The continuously variable transmission control device according to claim 4, wherein the target deceleration of the learning map in the situation is updated.   The control device for a continuously variable transmission according to any one of claims 2 to 5, wherein the parameter is presence or absence of a forward vehicle.   The continuously variable transmission control device according to any one of claims 2 to 6, wherein the parameter is whether or not a winding road.   The continuously variable transmission control device according to any one of claims 2 to 7, wherein the parameter is a road gradient.   The continuously variable transmission control device according to any one of claims 2 to 8, wherein the parameter is a vehicle speed.   When the learning means sets the learning value of the target deceleration while traveling on an arbitrary downhill road, the learning means sets the learned value of the target deceleration from the traveling on the downhill road next to the arbitrary downhill road to the downhill The control device for a continuously variable transmission according to any one of claims 1 to 9, wherein use in the gear ratio control means is permitted.   The learning means sets the learning value of the target deceleration while traveling on the arbitrary downhill road, and then performs at least one of climbing road traveling, flat road traveling, and stopping for a predetermined time or more. 11. The continuously variable transmission control device according to claim 10, wherein the use of the learned value of speed is permitted.

Images