JP2013213538A - Control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an automatic transmission, which can improve fuel economy by quickly determining whether a road is up-hill road or not, immediately performing neutral control upon making stop on a flat road or a downhill road, and appropriately adjusting the joining pressure of a clutch on an up-hill road according to a braking force.SOLUTION: Up-hill road determination means 24 determines whether a road is up-hill road or not based on immediate detection angle information detected by road surface gradient angle detection means 21, 34, and 35 until smoothing processing of a processing part 23 is completed after control conditions have been established, and determines whether the road is up-hill road or not based on processing angle information subjected to smoothing processing after the completion of the smoothing processing. Control means 20 executes, when the control conditions are established and a traveling road is up-hill road, joining pressure control of a clutch 43 based on the detection angle information or the processing angle information used for the up-hill road determination of the up-hill road determination means 24, and a braking force Bf.

Description

  The present invention relates to a control device for an automatic transmission according to neutral control.

  In a vehicle equipped with an automatic transmission having a torque converter, when a travel range such as the D range or the R range is selected, even if the accelerator pedal opening is zero, a predetermined torque (so-called creep torque) is applied to the vehicle. Occurs. With this creep torque, it is possible to run at a very low speed when entering a garage or in a traffic jam with only a brake operation without operating the accelerator, and even if the brake is released when starting on a slope, the vehicle can be prevented from moving backward. Driving operability under predetermined conditions is improved.

  When creep torque is generated, the vehicle is stopped and held by depressing the brake, but creep torque from the engine is generated even during this stop and hold, and the creep torque is not used for vehicle travel. Is applied with a driving load that does not contribute to vehicle travel. In such a situation, neutral control is known that suppresses engine driving load and improves fuel efficiency.

  Neutral control is performed when the travel range is selected, the vehicle is in a stopped state, the accelerator pedal opening is zero, and the brake operation is performed at the same time. The (engagement element capable of interrupting power transmission) is opened to a neutral state.

  However, when neutral control is performed on an uphill road, the vehicle may slide down when the braking force is not sufficiently applied. For this reason, a technique for canceling the neutral control on the uphill road is disclosed in Patent Document 1 and the like.

  In the technique of Patent Document 1, an acceleration sensor is used as an uphill detection device used for determining whether neutral control is to be performed. Data itself (hereinafter referred to as raw data) detected by the acceleration sensor is used for a driving system such as an engine. Since it is affected by vibration, it is not used as it is, and data obtained by processing raw data (hereinafter referred to as true acceleration data) is used as data corresponding to the slope of the uphill road. This true acceleration data has a delay time of about 1 second with respect to the detection of raw data.

  In the technique of Patent Document 1, determination of a road surface gradient where the vehicle is stopped (hereinafter referred to as gradient determination) is performed using true acceleration data detected by an acceleration sensor. In this technology, the true acceleration data immediately after stopping on the uphill road is below the level of the uphill judgment threshold, but the true acceleration data corresponds to the true road surface gradient after a certain period of time since the stop. Focusing on the fact that it may be higher than the road judgment threshold level, and if the true acceleration data is below the uphill road judgment threshold level immediately after stopping, the clutch is gradually turned on in preparation for immediate neutral control. The clutch is released or the clutch is returned to the engaged state in accordance with the gradient determination performed after a certain period of time in parallel.

JP 2004-190764 A

However, the control as in Patent Document 1 has the following problem (I) or (II).
(I) When the slope of the road surface on which the vehicle has stopped is a steep climb, there is a risk that the vehicle will fall down if the neutral control clutch is released without considering the slope.
(II) Since it takes a predetermined time (delay time) to obtain true acceleration data for determining the gradient, the execution of neutral control is delayed.

  Further, even when the vehicle is stopped on the uphill road when the travel range is selected, if the braking force is large, the vehicle is stopped and held without falling off. Therefore, in such a case, the neutral control is effective. On the other hand, if the vehicle is stopped on an uphill road when the travel range is selected, the vehicle may slide down if the braking force is small. Therefore, in such a case, it is desirable to generate the creep torque while avoiding the cancellation of the neutral control, that is, the release of the clutch of the automatic transmission. However, in the technique of Patent Document 1, when the vehicle stops on an uphill road, the neutral control is uniformly canceled regardless of the braking force.

  The present invention was devised in view of such a problem, and promptly determines whether or not a road is an uphill road, and immediately implements neutral control when stopping on a flat road or a downhill road. An object of the present invention is to provide a control device for an automatic transmission, which can improve the fuel consumption by appropriately adjusting the clutch engagement pressure in accordance with the force.

(1) In order to achieve the above-mentioned object, a control device for an automatic transmission according to the present invention includes a clutch (engagement element) capable of transmitting engine output to a drive wheel of a vehicle and connecting and disconnecting the output. A control device for an automatic transmission having a shift range detecting means for detecting a shift range of the automatic transmission, a vehicle speed detecting means for detecting a vehicle speed of the vehicle, and a brake for detecting presence or absence of a brake operation of the vehicle Operation detection means, road surface gradient angle detection means for detecting the gradient angle of the road surface of the vehicle, processing means for converting the detected angle information detected by the road surface gradient angle detection means into processing angle information obtained by smoothing, Uphill road determination means for determining whether the traveling road surface is an uphill road based on information from the road surface gradient angle detection means and the processing means, the shift range detection means, and the vehicle speed detection means. And the control condition that the shift range is a travel range, the vehicle is in a stopped state, and the brake operation is present, based on each detection information of the brake operation detection means and determination information by the uphill road determination means If it is determined that the traveling road surface is not an uphill road, neutral control for releasing the clutch is performed, and if it is determined that the traveling road surface is an uphill road, the neutral control is performed. A control means that does not implement and a brake force detection means that detects a braking force generated by the brake operation, and the climbing slope determination means until the smoothing process by the processing means is completed after the control condition is satisfied. , Based on the latest detected angle information, it is determined whether the road surface is an uphill road, and after completion of the processing by the processing means, the processing angle Based on the information, it is determined whether or not the road surface is an uphill road, and when the control condition is satisfied and the traveling road surface is determined to be an uphill road, the control condition is satisfied. Until the smoothing process by the processing means is completed, based on the latest detected angle information and the braking force, and after the processing by the processing means is completed, based on the processing angle information and the braking force, Each is characterized in that the joint pressure control of the clutch is performed.
Moreover, it is preferable that the uphill road determination unit performs the determination when the vehicle speed detected by the vehicle speed detection unit decreases to a low speed state that is equal to or lower than a determination reference vehicle speed.

(2) The joining pressure control by the control means increases the joining pressure of the clutch as the gradient angle applied to the detection angle information or the processing angle information used for the determination by the uphill road determination means increases. It is preferable to reduce the clutch engagement pressure as the braking force increases.
(3) It is preferable that the control means puts the clutch into an engaged state when the control condition is not satisfied.

  (4) The road surface gradient angle detection unit includes a longitudinal acceleration sensor that detects a longitudinal acceleration of the vehicle, and when the vehicle is stopped, the longitudinal acceleration is based on a correspondence relationship between the vehicle longitudinal acceleration and the gradient angle. The detected angle information is detected from the longitudinal acceleration detected by the sensor, and when the vehicle is traveling, the longitudinal acceleration detected by the longitudinal acceleration sensor based on the vehicle longitudinal acceleration and the correspondence between the braking force and the gradient angle. It is preferable that the detected angle information is detected from a direction acceleration and a braking force detected by the braking force detection means.

  Therefore, according to the control apparatus for an automatic transmission of the present invention, the uphill road determination unit is the latest detected by the road surface gradient angle detection unit until the smoothing process by the processing unit is completed after the control condition is satisfied. In order to determine whether or not the road is an uphill road based on the detected angle information, when the control condition is satisfied, the uphill road is determined without waiting for the time required for the smoothing processing by the processing means (the delay time). If a negative determination is made in this uphill road determination, that is, if the vehicle is stopped on a flat road or a downhill road, neutral control for releasing the clutch is performed. Therefore, the neutral control can be performed immediately when the vehicle stops on a flat road or a downhill road by performing the uphill road determination without waiting for the delay time.

  In contrast to the prior art that uses acceleration data after the delay time required for the smoothing process, the control device for the automatic transmission according to the present invention does not wait for the delay time required for the smoothing process. The implementation of is not delayed.

  On the other hand, if an affirmative determination is made in the uphill road determination, that is, if the vehicle is stopped on the uphill road, neutral control is not performed, and the detected angle information or the processed angle information and the brake detected by the braking force detection means In order to perform the clutch engagement pressure control of the automatic transmission based on the force, the clutch engagement pressure is appropriately adjusted according to the gradient angle of the traveling road surface and the braking force, to prevent the vehicle from sliding down, Fuel consumption can be improved by suppressing the driving load of an oil pump or the like that is a generation source of the bonding pressure.

  If the vehicle is stopped on an uphill road, there is a risk that the vehicle will slide down in the prior art in which the neutral control clutch is released without considering the gradient. In addition, it is possible to prevent the vehicle from sliding down in consideration of the braking force.

  When it is determined that the control condition is satisfied and the traveling road surface is an uphill road, the control means is based on the detected angle information and the braking force until the smoothing process by the processing means is completed. Performs the clutch joint pressure control based on the processing angle information and the braking force. Therefore, when the vehicle stops on an uphill road, for example, the clutch is uniformly controlled until the smoothing process is completed, and compared with the technique of reducing the clutch joint pressure when the smoothing process is completed, The present invention can reduce the bonding pressure until the smoothing process is completed, and can improve fuel consumption. In addition, since a change in the bonding pressure when the smoothing process is completed can be reduced, a shock due to a change in the bonding pressure can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a principal part block diagram of the control apparatus of the automatic transmission concerning one Embodiment of this invention, and the vehicle with which this apparatus is equipped. It is a flowchart which shows the detection of the gradient angle by the control apparatus of the automatic transmission concerning one Embodiment of this invention. It is a flowchart which shows determination of the control conditions by the control apparatus of the automatic transmission concerning one Embodiment of this invention. It is a flowchart which shows the control implemented by the control apparatus of the automatic transmission concerning one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the clutch of this invention means the engagement element which can interrupt | block power transmission.
[One Embodiment]
A control device for an automatic transmission according to the present embodiment is installed in a vehicle such as an automobile.

[1. Configuration of drive system, power transmission system and sensors]
First, with reference to FIG. 1 which shows the principal part structure of a vehicle, the structure of a drive system and a power transmission system is demonstrated.
The vehicle according to the present embodiment includes an engine 1 that is a drive source of the vehicle, and a torque converter 3, an automatic transmission 4, a power transmission mechanism 5, and drive wheels 6 in order of the output transmission direction of the engine 1. ing.
An oil pump 2 driven by output rotation is connected to the engine 1.
The oil pump 2 pumps hydraulic oil (generally ATF; Automatic Transmission Fluid) for the automatic transmission 4 or the like, and is connected to a joining pressure adjusting mechanism 10 described later via an oil passage.

  The torque converter 3 includes a pump impeller 3a connected to the output shaft 1a of the engine 1 and a turbine runner 3b connected to the input shaft 41 of the automatic transmission 4, and the engine input via the pump impeller 3a. 1 is transmitted to the turbine runner 3 b and transmitted to the automatic transmission 4.

  The automatic transmission 4 includes a start clutch (clutch) 43 capable of connecting / disconnecting power transmission (output transmission) and a continuously variable transmission mechanism between an input shaft 41 and an output shaft 42. This continuously variable transmission mechanism has a primary pulley 44, a secondary pulley 45, and belts 46 wound around these pulleys 44, 45. The effective radius) is adjusted to change the gear ratio. In the present embodiment, the continuously variable transmission mechanism is described as a belt type, but instead of this, a chain type or toroidal type continuously variable transmission may be used.

  The start clutch 43 includes a planetary gear 43a that switches a power transmission path between the engine 1 side and the continuously variable transmission mechanism side, a forward clutch 43b, and a reverse brake 43c. The clutch 43 b and the brake 43 c have their respective joint pressures adjusted by the hydraulic fluid supplied from the joint pressure adjusting mechanism 10.

  The junction pressure adjusting mechanism 10 is configured to include a solenoid valve, a drain, and the like, and adjusts the junction pressure of the start clutch 43. The joint pressure adjusting mechanism 10 adjusts a part of the hydraulic oil pumped by the oil pump 2 in accordance with an instruction signal from an ATCU (control unit, automatic transmission control unit) 20 described later, and the pressure is adjusted. The hydraulic oil is supplied to the piston chamber (not shown) of the forward clutch 43b or the piston chamber (not shown) of the reverse brake 43c, and a joint pressure is applied to each of the clutch 43b and the brake 43c.

  The forward clutch 43b is fastened and joined at the time of traveling when the forward traveling range such as the drive (D) range is selected. When the forward clutch 43b is engaged, the input shaft 41 of the automatic transmission 4 and the input shaft 44a of the primary pulley 44 rotate in the same direction. On the other hand, the reverse brake 43c is fastened and the joint pressure is increased during reverse travel when the reverse (R) range (reverse travel range) is selected. When the reverse brake 43c is engaged, the input shaft 41 of the automatic transmission 4 and the input shaft 44a of the primary pulley 44 rotate in opposite directions.

When the vehicle travels such as the R range or the D range, the clutch 43b and the brake 43c are engaged exclusively with each other. When the forward clutch 43b is engaged, the reverse brake 43c is released and the forward clutch 43b is engaged. If released, the reverse brake 43c is engaged. On the other hand, when the non-traveling range of the parking (P) range or the neutral (N) range is selected and when the neutral control to be described later is performed, both the clutch 43b and the brake 43c are released with the joint pressure lowered.
Drive wheels 6 are connected to an output shaft 42 of the automatic transmission 4 via a power transmission mechanism 5 having a differential, a drive shaft, and the like.

A brake mechanism (not shown) is attached to each wheel (including the drive wheel 6) of the vehicle. Each brake mechanism is connected via a brake fluid path to a master cylinder (not shown) that generates a brake fluid pressure corresponding to the depression force of a driver's brake pedal (not shown). Brake force is generated on the vehicle.
Next, the configuration of sensors will be described with reference to FIG.

  The shift range sensor (shift range detection means) 31 detects the shift range of the automatic transmission 4 set by the driver operating the shift lever. For example, the contact point is switched in accordance with the switching of the shift range, and an inhibitor switch for preventing the starter motor for starting the engine other than in the neutral and parking ranges can be used as the shift range sensor 31. Information (detection information) of each shift range P, R, N, D detected by the shift range sensor 31 is transmitted to the ATCU 20.

  The vehicle speed sensor 32 detects the vehicle speed V of the vehicle. As the vehicle speed sensor 32, a wheel speed sensor that detects the rotation speed of the wheel or a rotation speed sensor that detects the rotation speed of the output shaft 42 of the automatic transmission 4 can be used. Information (detection information) on the vehicle speed V detected by the vehicle speed sensor 32 is transmitted to the ATCU 20.

  The brake switch (brake operation detecting means) 33 detects the presence or absence of a brake operation of the vehicle. If this switch 33 is ON, the brake pedal is depressed, and if it is OFF, the brake pedal is not depressed. An ON / OFF signal (detection information) detected by the brake switch 33 is transmitted to the ATCU 20.

The master cylinder pressure sensor (brake force detection means) 34 detects the brake fluid pressure according to the depression force of the driver's brake pedal. That is, as the brake fluid pressure increases, the braking force to the wheels increases, and the brake fluid pressure corresponds to the brake force. Therefore, the master cylinder pressure sensor 34 detects the brake force _Bf due to the brake operation. Is. Information (detection information) of the braking force B _f detected by the master cylinder pressure sensor 34 is transmitted to the ATCU 20.

  The acceleration (G) sensor (longitudinal acceleration sensor) 35 detects a longitudinal acceleration (hereinafter simply referred to as acceleration) A of the vehicle. This sensor 35 detects a positive acceleration A when the vehicle is accelerating or when the vehicle is stopped on an uphill road, and is negative when the vehicle is decelerated or when the vehicle is stopped on a downhill road. The acceleration (deceleration) A is detected. Information on the acceleration A detected by the acceleration sensor 35 is transmitted to the ATCU 20.

[2. Configuration of control system]
[2.1 Outline of ATCU]
The vehicle includes an ATCU 20 that controls a wide range of systems related to the automatic transmission 4. The ATCU 20 is an electronic control unit configured as an LSI device or an embedded electronic device in which a microprocessor, a ROM, a RAM, and the like are integrated, for example.

The ATCU 20 controls a wide range of systems related to the automatic transmission 4. In the present embodiment, the configuration related to the control performed based on the information detected by the sensors 31, 32, 33, 34, and 35 will be described. To do. This control includes neutral control and junction pressure control, which will be described in detail later.
The ATCU 20 includes a gradient angle detection unit 21 having a memory 21a, a control condition determination unit 22, a processing unit (processing unit) 23, and an uphill road determination unit (uphill road determination unit) 24 as functional blocks for performing control. And a bonding pressure calculation unit 25.

[2.1.1 Configuration of Gradient Angle Detection Unit]
<Road slope angle detection means>
The gradient angle detection unit 21 uses the information on the acceleration A detected by the acceleration sensor 35 and the information on the brake force B _f detected by the master cylinder pressure sensor 34 to determine the gradient angle θ _p of the traveling road surface of the vehicle. To detect. Therefore, the acceleration sensor 35, the master cylinder pressure sensor 34, and the gradient angle detection unit 21 constitute road surface gradient angle detection means.
The traveling road surface includes not only the road surface when the vehicle is traveling but also the road surface when the vehicle is stopped. Further, the gradient angle θ _p means an inclination angle of the traveling road surface in the vehicle front-rear direction.

<Premise of slope angle detection>
The detection of the gradient angle θ _p by the gradient angle detector 21 is started when the brake switch 33 is ON and the vehicle speed V detected by the vehicle speed sensor 32 is equal to or lower than a predetermined vehicle speed (judgment reference vehicle speed) V _TH. Is ended or when the vehicle speed V is higher than the predetermined vehicle speed _VTH . The predetermined vehicle speed V _TH here is set in advance as a determination threshold value for determining whether or not the vehicle is at a low vehicle speed, such as 10 km / h.
Further, the detection of the gradient angle θ _p by the gradient angle detector 21 is sequentially performed at a predetermined detection cycle. The gradient angle detector 21 cumulatively stores the gradient angle θ _p detected in a predetermined detection cycle in the memory 21a.
The gradient angle detection unit 21 has a stop time map and a travel time map, and detects the gradient angle θ _p using different parameters and maps when the vehicle is stopped and when the vehicle is traveled.

<Gradient angle detection principle when the vehicle is stopped>
When the vehicle is stopped, that is, when the vehicle speed V detected by the vehicle speed sensor 32 is zero, the stop time map in which the correspondence between the longitudinal acceleration of the vehicle and the gradient angle of the traveling road surface is set in advance, and the acceleration sensor 35 The gradient angle θ _p is detected using the information of acceleration (hereinafter also referred to as acceleration value or detected acceleration value) A detected by the above.
If it is a flat road, the acceleration sensor 35 does not detect the acceleration, but reacts to gravity if there is a gradient on the running road surface, and a positive acceleration value on an ascending slope (uphill road) and a negative value on a downhill slope (downhill road). An acceleration value is detected.

In addition, for example, when stopping on an uphill road with a steep slope (uphill road with a large slope angle), the detected acceleration value is higher than when stopping on an uphill road with a gentle slope (uphill road with a small slope angle). growing. A map in which the correspondence relationship between the gradient angle and the detected acceleration value (vehicle longitudinal acceleration) having such characteristics is set experimentally or empirically in advance is used as the stop time map.
Therefore, when the vehicle is stopped, the gradient angle detection unit 21 reads the gradient angle corresponding to the detected acceleration value A from the stop time map, and detects the gradient angle θ _p .

<Gradient angle detection principle during vehicle travel>
When the vehicle is traveling, that is, when the vehicle speed V detected by the vehicle speed sensor 32 is not zero, in addition to the information on the acceleration value A, the information on the braking force _Bf detected by the master cylinder pressure sensor and the longitudinal direction of the vehicle The gradient angle θ _p is detected using a travel time map in which the correspondence relationship between acceleration and braking force and the gradient angle is set in advance.

For example, when a large braking force is applied on an uphill road having a predetermined gradient while the vehicle is traveling, the detected acceleration value is smaller than when a small braking force is applied on an uphill road having the same gradient. In addition, the detected acceleration value is larger on a steep slope uphill with a predetermined braking force applied than on a gentle slope uphill with the brake force applied. A map in which the vehicle longitudinal acceleration (vehicle longitudinal acceleration) and the correspondence relationship between the braking force and the gradient angle are experimentally or empirically set in advance is used as the travel time map.
Accordingly, the gradient detection unit 21, when the vehicle is running, reads the slope angle corresponding from the running time of the map on the detected acceleration value A and the braking force B _f, detects a gradient angle theta _p.

[2.1.2 Configuration of Control Condition Determination Unit]
The control condition determination unit 22 determines an execution condition (hereinafter referred to as a control condition) of control performed by the ATCU 20. The ATCU 20 starts control if the control condition is satisfied, and cancels control if the control condition is not satisfied.
The determination of the control condition is started when the brake switch 33 is ON and the vehicle speed V is equal to or lower than a predetermined vehicle speed (determination reference vehicle speed) V _TH as in the case of detecting the gradient angle θ _p , and the brake switch 33 is turned OFF. Alternatively, the process is terminated when the vehicle speed V is higher than the predetermined vehicle speed _VTH .

The control condition is satisfied when any of the following conditions (1) to (3) is satisfied, and is not satisfied unless any one of the conditions (1) to (3) is satisfied.
(1) The shift range detected by the shift range sensor 31 is the forward travel range.
(2) The vehicle speed detected by the vehicle speed sensor 32 is zero (the vehicle is stopped).
(3) The brake switch 33 is ON (the vehicle has a brake operation).
Therefore, the control condition determining unit 22 determines the above conditions (1) to (3) and determines the control conditions.

[2.1.3 Configuration of processing unit]
Processor 23 to process angle theta _t the slope angle detector 21 information of the detected slope angle theta _p by (detection angle information) and smoothed information (process angle information).
The gradient angle θ _p is detected using information on the acceleration A detected by the acceleration sensor 35, and a disturbance component due to a nose dive when the vehicle stops due to vibration or braking force of the drive system of the vehicle is detected. There is a risk that the actual slope angle of the road surface is adjusted. Therefore, the processing unit 23, the information of the gradient angle theta _p and smoothed, performs processing for obtaining the processing angle theta _t as stable information slope angle theta _p.

The smoothing processing by the processing unit 23, and slope angle theta _p the latest is the memory in the memory 21a (the most recent), the detection cycle memory gradients angle theta _p in the immediately preceding slope angle theta _p (one cycle before) If the difference between and becomes a predetermined value or less, it is possible to adopt a process in which the gradient angle θ _p is stable. This predetermined value is a threshold value for determining that the gradient angle θ _p has converged and stabilized, and a variation threshold value for the gradient angle θ _p that can be ignored at the time of stabilization is preset.
The smoothing processing by the processing unit 23 is not limited to this, and low-pass filter processing such as calculating a moving average of the gradient angle θ _{p for} a predetermined time such as 1 second may be employed.

[2.1.4 Configuration of the climbing slope determination unit]
The uphill road determination unit 24 determines whether or not the traveling road surface of the vehicle is an uphill road based on information from the road surface gradient angle detection unit and the processing unit 23. This determination (hereinafter referred to as climbing road determination) is based on the premise that the control condition determination unit 22 determines that the control condition is satisfied.
Specifically, if the gradient angle θ applied to the information from the road surface gradient angle detection means and the processing unit 23 is positive (θ> 0), the uphill road determination unit 24 determines that the traveling road surface of the vehicle is an uphill road. If the slope angle θ is not positive (θ ≦ 0), it is determined that the traveling road surface of the vehicle is not an uphill road, that is, a flat road or a downhill road. An area having a gradient angle θ having a width near zero is set as a flat road, and an uphill road determination threshold θ ₀ (positive minute value) is set. If the gradient angle θ is equal to or greater than the threshold θ ₀ (θ ≧ θ ₀ ), it may be determined that the road is an uphill road.
In the uphill road determination, different information is used before and after the smoothing process by the processing unit 23 is completed. Hereinafter, the uphill road determination by the uphill road determination unit 24 will be described for each determination time.

<Climb judgment before smoothing>
Before the smoothing process by the processing unit 23 is completed, information on the latest (most recent) gradient angle θ _p detected by the road surface gradient angle detection unit is used as the gradient angle θ.
For example, the smoothing process by the processing unit 23 is not completed during the period when the gradient angle θ _p is not stably converged due to the nose dive of the vehicle immediately after stopping on the uphill road, and the uphill road determination unit 23 As a provisional process until information on the smoothed processing angle θ _t is obtained, an uphill road determination is performed using the gradient angle θ _p as the gradient angle θ.

<Climb judgment after completion of smoothing>
After the smoothing process by the processing unit 23 is completed, information on the processing angle θ _t smoothed by the processing unit 23 is used as the gradient angle θ.
For example, when the slope angle θ _p is stably converged after stopping on an uphill road and the smoothing process by the processing unit 23 is completed, the uphill road determination unit 23 is assumed to be provisional when the smoothing process is completed. the slope angle theta _p used as the slope angle theta replaced with smoothed treated processed angle theta _t, performs uphill determining the processing angle theta _t as the slope angle theta.

[2.1.5 Configuration of Bonding Pressure Calculation Unit]
The joining pressure calculation unit 25 calculates the joining pressure P _C of the forward clutch 43b based on the gradient angle θ used in the above-described uphill road determination and the braking force B of the vehicle. This calculation is sequentially performed at a predetermined calculation cycle, and the brake force B _f detected by the master cylinder pressure sensor 34 is used as the brake force B. However, if there is no change in the brake force _Bf, that is, if the brake force _Bf detected immediately before (one cycle before) and the latest brake force _Bf are the same value, the joint pressure is applied in this cycle. The latest calculation result is maintained without calculation.

The bonding pressure P _C which is calculated by the joining pressure calculating unit 25 is the forward clutch 43b is creep torque of the full engagement state is at the upper limit, it is possible to consider the braking force B _f, to stop holding the vehicle It means the target joining pressure of the forward clutch 43b.
The calculation by the joining pressure calculation unit 25 is based on the premise that the control condition determination unit 22 determines that the control condition is satisfied, and the uphill road determination unit 24 determines that the traveling road surface of the vehicle is an uphill road. .

Joint pressure calculating unit 25, when the forward running range such D-range is detected by the shift range sensor 31 calculates the bonding pressure P _C of the forward clutch 43. Hereinafter, the calculation of the joining pressure of the forward clutch 43b when the forward travel range is selected will be described. In this case, the reverse brake 43c remains open when the D range is selected, and the junction pressure is not calculated.
The junction pressure calculation unit 25 calculates the junction pressure P _C that increases as the gradient angle θ used for the uphill road determination increases, and calculates the junction pressure P _C that decreases as the brake force B of the vehicle increases. To do.
Further, the bonding pressure calculation unit 25 has a bonding pressure map. Hereinafter, the bonding pressure map will be described.

When the vehicle stops on an uphill road, the force to slide the vehicle increases as the gradient angle of the traveling road surface increases. Therefore, in order to stop and hold the vehicle, a greater drag force is required as the gradient angle of the traveling road surface increases. This drag is a combination of the resistance corresponding to the braking force B and the resistance corresponding to the creep torque transmitted to the drive wheels 6 by the joining pressure of the forward clutch 43b. Of course, if the forward clutch 43b is in the disengaged state, no creep torque is generated, so the drag corresponds to the braking force B. A joint pressure map having such characteristics, in which the correspondence relationship between the gradient angle and the braking force and the joint pressure is set experimentally or empirically in advance.
When the vehicle stops on an uphill road, if the braking force is large, the vehicle does not slide down. Therefore, the joining pressure that sets the forward clutch 43b in the released state is also set in the joining pressure map.

That is, the bonding pressure calculation unit 25 calculates the bonding pressure P _C by reading the bonding pressure corresponding to the gradient angle θ and the braking force B from the bonding pressure map. This calculation is sequentially performed at a predetermined calculation cycle. Therefore, when the braking force B _f that is detected by the master cylinder pressure sensor 34 is varied, along with this, also it varies bonding pressure P _C which is calculated by the joining pressure calculating unit 25.

[3. Controls implemented by ATCU]
The ATCU 20 is connected to the neutral control based on the information from the sensors 31, 32, 33, 34, 35 and the information such as the determination information from the functional blocks 21, 22, 23, 24, 25. And pressure control. These controls are started when the control condition determination unit 22 determines that the control condition is satisfied, and is canceled (terminated) when it is determined that the control condition is not satisfied.

[3.1 Neutral control]
Neutral control is control which makes the starting clutch 43 open.
Specifically, the ATCU 20 outputs a control instruction signal for lowering the joint pressure of both the forward clutch 43b and the reverse brake 43c to the joint pressure adjusting mechanism 10 to release the clutch, and the neutral control for releasing the start clutch 43. To implement.

  This neutral control is performed when the uphill road determination unit 24 determines that the traveling road surface is not an uphill road, that is, a flat road or a downhill road. On the other hand, when the uphill road determination unit 24 determines that the traveling road surface is an uphill road, the neutral control is not performed and the following bonding pressure control is performed.

[3.2 Bonding pressure control]
The joining pressure control is for controlling the joining pressure of the starting clutch 43. That, ATCU 20 outputs a control instruction signal for bonding pressure P _C calculated by joint pressure calculating section 25 to the junction pressure adjustment mechanism 10, to control the joining pressure of the starting clutch 43b. This control is performed when the forward travel range is selected.

Therefore, before the smoothing process by the processing unit 23 is completed, the ATCU 20 acquires information on the latest (most recent) gradient angle θ _p stored in the memory 21 a and the braking force B _f detected by the master cylinder pressure sensor 34. After the completion of the smoothing process, based on the information of the above, based on the information of the gradient angle θ _t smoothed by the processing unit 23 and the information of the brake force B _f detected by the master cylinder pressure sensor 34 Then, the joint pressure control of the clutch 43 is performed.

For example, larger vehicle is uphill by stop and braking force B _f be a state becomes a bonding pressure bonding pressure P _C which is calculated by the joining pressure calculating section 25 to the forward clutch 43b in the open state, the ATCU20 As in the neutral control, the forward clutch 43b and the reverse brake 43c are controlled to be released.

[Action / Effect]
Since the control apparatus for an automatic transmission according to an embodiment of the present invention is configured as described above, the flow shown in FIGS. 2 to 4 is performed by the ATCU 20 at predetermined intervals. 2 and 3 are performed in parallel. When the flow of FIG. 4 is performed, the flows of FIGS. 2 and 3 are also performed in parallel.

The flow shown in FIG. 2 shows the detection of the gradient angle θ _p of the traveling road surface by the gradient angle detector 21. The vehicle speed V detected by the vehicle speed sensor 32 and the brake switch 33 is ON is a predetermined vehicle speed (determination reference vehicle speed). ) It is triggered by being below V _TH .
In step A10, the acceleration A detected by the acceleration sensor 35 and the brake force _Bf detected by the master cylinder pressure sensor are read.
In step A20, based on the read elaborate acceleration A and the brake force B _f in step A10, with reference to the previously described stop time maps and travel time map, for detecting a slope angle theta _p.
In step A30, the gradient angle θ _p detected in step 20 is stored in the memory 21a.
Then, the current detection cycle ends (returns).

The flow shown in FIG. 3 shows the determination of the control condition by the control condition determination unit 22, and, similarly to the detection of the gradient angle θ _p shown in FIG. Reference vehicle speed) _{Triggered by VTH} or less.

In step B10, it is determined whether or not the shift range detected by the shift range sensor 31 is a forward travel range. If this shift range is the forward travel range, the process proceeds to step B20, and if the shift range is not the forward travel range, the process proceeds to step B50.
In step B20, it is determined whether or not the vehicle speed V detected by the vehicle speed sensor 32 is zero. If the vehicle speed V is zero, the process proceeds to step B30, and if the vehicle speed V is not zero, the process proceeds to step B50.
In step B30, it is determined whether or not the brake switch 33 is ON. If the brake switch 33 is ON, the process proceeds to step B40, and if the brake switch 33 is OFF, the process proceeds to step B50.

The control condition is satisfied when any of these steps B10 to B30 is determined to be affirmative (YES), and the control condition is not satisfied when any of steps B10 to B30 is determined to be negative (NO). In the following steps B40 and B50, a flag F1 that is set to 1 when the control condition is satisfied and is set to 0 when the control condition is not satisfied is used.
In step B40, the flag F1 is set to 1. Then, the current determination cycle ends (returns).
In step B50, the flag F1 is set to 0. Then, the current determination cycle ends (returns).

The flow shown in FIG. 4 shows the control performed by the ATCU 20, and is started when the control condition is satisfied, that is, when the flag F1 is set to 1. In this flow, a flag F2 that is set to 0 before the completion of the smoothing process by the processing unit 23 and set to 1 after the completion of the smoothing process is used. The initial value of this flag F2 is set to 0.
In Step C1, it is determined whether or not the flag F2 is 1. If the flag F2 is 1, the process proceeds to step C10, and if the flag F2 is 0, the process proceeds to step C2.
In step C2, it is determined whether or not the smoothing process of the gradient angle θ _p by the processing unit 23 has been completed. If it is after the completion of the smoothing process, the process proceeds to step C3, and if it is before the completion of the smoothing process, the process proceeds to step C5.

In step C3, uphill determination by climbing road determination unit 24, and substitutes the slope angle theta _t the slope angle theta for use in bonding pressure operation by bonding pressure calculating unit 25. In step C4, the flag F2 is set to 1, and the process proceeds to step C10.
In step C5, it substitutes the slope angle theta _p to the gradient angle theta for use in an uphill road judging and bonding pressure calculating. In step C6, the flag F2 is set to 0, and the process proceeds to step C10.

In step C10, it is determined whether or not the gradient angle θ is positive. This step C10 is a step in which the uphill road determination unit 24 performs the uphill road determination. If the gradient angle θ is positive, the process proceeds to step C20, and if the gradient angle θ is not positive, the process proceeds to step C100.
In step C20, the brake force B _f detected by the master cylinder pressure sensor 34 is read. Then, the process proceeds to step C30.

In step C30, the brake force _Bf read in step C20 of the immediately preceding cycle (one cycle before) is compared with the brake force _Bf read in step C20 of the current cycle, and the brake force _Bf is changed. It is determined whether or not there is. If the brake force _Bf is changed, the process proceeds to step C40, and if the brake force _Bf is not changed, the process proceeds to step C60. If it is the first control cycle, the process proceeds to step C40.
In step C40, the brake force _Bf of the current control cycle is substituted into the vehicle brake force B used for the junction pressure calculation of the junction pressure calculation unit 25. Then, the process proceeds to step C50.

In step C50, it calculates the junction pressure P _C of the starting clutch 43 on the basis of the slope angle θ and the brake force B. Then, the process proceeds to step C60.
In Step C60, a control instruction signal for the bonding pressure P _C is output to the bonding pressure adjusting mechanism 10. Then, the process proceeds to step C70.

In Step C100, neutral control is performed. That is, the ATCU 20 outputs a control instruction signal that instructs the joint pressure adjusting mechanism 10 to lower the joint pressure in order to open the start clutch 43. Then, the process proceeds to step C70.
In step C70, the flag F1 relating to the establishment of the control condition is read, and the process proceeds to step C80.

In Step C80, it is determined whether or not the flag F1 is 0, that is, whether or not the control condition is satisfied. If the flag F1 is 0, the process proceeds to step C90. If the flag F1 is 1, the current control cycle is ended (returned).
In step C90, the control (bonding pressure control or neutral control) performed by the ATCU 20 is canceled (terminated). Then, the current control cycle ends (returns).

Therefore, in the automatic transmission control device according to the present invention, the uphill road determination unit 24 immediately before the completion of the smoothing process by the processing unit after the control condition is satisfied is immediately before the road surface gradient angle detection unit detects. Since the uphill road determination is performed based on the information of the gradient angle θ _p, the uphill road can be determined without waiting for the time required for the smoothing process (that is, the delay time) by the processing unit 23 when the control condition is satisfied. it can. If a negative determination is made in this uphill road determination, that is, if the vehicle is stopped on a flat road or a downhill road, the above-mentioned delay time is waited in order to carry out neutral control for releasing the start clutch 43. By performing the uphill road determination without any change, neutral control can be immediately performed when the vehicle stops on a flat road or a downhill road.

  In contrast to the prior art that uses acceleration data after the delay time required for the smoothing process, the control device for the automatic transmission according to the present invention does not wait for the delay time required for the smoothing process. The implementation of is not delayed.

On the other hand, if an affirmative determination is made in the uphill road determination, that is, if the vehicle is stopped on the uphill road, neutral control is not performed, information on the gradient angle θ _p or information on the processing angle θ _t and the master cylinder pressure Based on the braking force B _f detected by the sensor 34, the joint pressure control of the forward clutch 43b of the automatic transmission 4 is performed, so that the gradient angle θ (gradient angle θ _p or processing angle θ _t ) of the traveling road surface and adjust the bonding pressure P _C of the appropriate forward clutch 43b in accordance with the braking force B, while preventing sliding down of the vehicle by suppressing the driving load of the oil pump 2 which is a source of bonding pressure P _C, Fuel consumption can be improved.

  If the vehicle is stopped on an uphill road, there is a risk that the vehicle will slide down in the prior art in which the neutral control clutch is released without considering the gradient. Considering θ and the braking force B, it is possible to prevent the vehicle from sliding down.

ATCU20, when road surface control condition is satisfied is determined to be an uphill road, until the completion of the smoothing processing by the processing unit 23 based on the information of the gradient angle theta _p and braking force B _f, the smoothing process completed after, based on the information and the braking force B _f of the processing angle theta _t, implementing the control joint pressure of the forward clutch 43b. Thus, when the vehicle stops on an uphill road, for example, the present invention reduces the joint pressure until the smoothing process is completed, compared to a technique for reducing the clutch joint pressure when the smoothing process is completed. It is possible to improve fuel efficiency. In addition, since a change in the bonding pressure when the smoothing process is completed can be reduced, a shock due to a change in the bonding pressure can be suppressed.

In the joint pressure control by the ATCU 20, the joint pressure of the forward clutch 43b is increased as the gradient angle θ increases, and the joint pressure of the forward clutch 43b is decreased as the brake force B increases. it can be set suitably joined pressure P _C in response to each.

If the control condition is not satisfied when the forward travel range is selected, the ATCU 20 puts the start clutch 43b into the engaged state. Therefore, even if the vehicle falls from the stopped state during the neutral control, the stopped state is released. Therefore, the control condition is not satisfied, and the starting clutch 43b is brought into the engaged state. Accordingly, creep torque is generated, and the vehicle can be prevented or suppressed from sliding down.
When the vehicle travels before smoothing processing by the processing unit 23, in addition to the information of the acceleration A, for detecting the gradient angle theta _p based on the information of the braking force B _f, it is accurately detected slope angle theta _p it can.

For example, if the braking force B _f be the vehicle is in a stopped state is greater by uphill, i.e., if the bonding pressure bonding pressure P _C calculated by joint pressure calculating section 25 to the forward clutch 43b in the open state The ATCU 20 controls the release of the forward clutch 43b and the reverse brake 43c in substantially the same manner as in the neutral control. Therefore, in a situation where the vehicle does not slide down on the uphill road, the load on the engine 1 is suppressed to reduce fuel consumption. Can be improved.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above-described embodiment, the automatic transmission has the continuously variable transmission mechanism. However, a stepped transmission mechanism (so-called step AT) may be used instead of the continuously variable transmission mechanism. In this case, the neutral control is not limited to the control for disengaging the starting clutch, but is a control for controlling a clutch or a brake that achieves a required gear stage of the stepped transmission mechanism and cutting off power transmission of the stepped transmission mechanism. Also good.

  In the above-described embodiment, the clutch is a start clutch interposed between the automatic transmission and the engine. However, the clutch is not limited to this, and the clutch between the automatic transmission and the drive wheel is not limited thereto. It may be interposed between them. For example, instead of the clutch, an auxiliary transmission to which a speed change function by a planetary gear mechanism or the like is added may be used.

  Moreover, although what performs neutral control and junction pressure control at the time of selection of a forward travel range was shown, you may implement neutral control and junction pressure control also at the time of selection of a reverse travel range. In this case, when the vehicle is stopped on the downhill road and the brake operation is performed, the joining pressure control is performed. According to this, fuel consumption can be further improved.

Moreover, although what uses an engine drive oil pump was shown, you may use not only this but a battery drive electric pump. In this case, by performing neutral control and junction pressure control, it is possible to suppress the driving load of the electric pump, suppress power consumption, and improve fuel efficiency.
In addition to the above conditions (1) to (3), the control condition is that the accelerator operation is not performed (the accelerator opening is zero) and the throttle opening is zero. May be added.

  The control apparatus for an automatic transmission according to the present invention is effective for an automobile having a clutch capable of connecting / disconnecting power transmission from a drive source, and various kinds of clutches having clutches capable of connecting / disconnecting power transmission from a drive source. It can be used for vehicles.

DESCRIPTION OF SYMBOLS 1 Engine 1a Output shaft 2 Oil pump 3 Torque converter 3a Pump impeller 3b Turbine runner 4 Automatic transmission 5 Power transmission mechanism 6 Drive wheel 10 Clutch pressure adjustment mechanism 20 ATCU (Automatic Transmission Control Unit)
21 Gradient angle detection unit 21a Memory 22 Control condition determination unit 23 Processing unit (processing means)
24 Uphill road judgment part (uphill road judgment means)
25 Clutch pressure calculation unit 31 Shift range sensor (shift range detection means)
32 Vehicle speed sensor (vehicle speed detection means)
33 Brake switch (brake operation detection means)
34 Master cylinder pressure sensor (brake force detection means)
35 Acceleration sensor 41 Input shaft 42 Output shaft 43 Starting clutch (clutch)
43a Planetary gear 43b Forward clutch 43c Reverse brake 44 Primary pulley 44a Input shaft 45 Secondary pulley 46 Belt

Claims (4)

A control device for an automatic transmission having a clutch capable of transmitting and receiving an output of an engine to a driving wheel of a vehicle and connecting and disconnecting the output.
Shift range detecting means for detecting a shift range of the automatic transmission;
Vehicle speed detecting means for detecting the vehicle speed of the vehicle;
Brake operation detecting means for detecting presence or absence of brake operation of the vehicle;
Road surface gradient angle detecting means for detecting the gradient angle of the traveling road surface of the vehicle;
Processing means for converting the detected angle information detected by the road surface gradient angle detecting means into processed angle information obtained by smoothing;
Climbing road determination means for determining whether or not the traveling road surface is an uphill road based on information from the road surface gradient angle detection means and the processing means;
Based on the detection information of the shift range detection means, the vehicle speed detection means, and the brake operation detection means and the determination information by the uphill road determination means, the shift range is a travel range, and the vehicle is stopped. And when it is determined that the traveling road surface is not an uphill road when the control condition that the brake operation is present is satisfied, neutral control for releasing the clutch is performed, and the traveling road surface is an uphill road. If it is determined that there is a control means that does not perform the neutral control,
Brake force detection means for detecting the brake force by the brake operation,
The uphill road determination means determines whether the road surface is an uphill road based on the latest detected angle information until the smoothing process by the processing means is completed after the control condition is satisfied. After the completion of the processing by the processing means, based on the processing angle information, determine whether the road surface is an uphill road,
If it is determined that the control condition is satisfied and the traveling road surface is an uphill road, the control means detects the most recent detection until the smoothing process by the processing means is completed after the control condition is satisfied. Based on angle information and the braking force, after the completion of the processing by the processing means, the clutch joint pressure control is performed based on the processing angle information and the braking force, respectively. Machine control device. The bonding pressure control by the control means is
Increasing the clutch engagement pressure as the gradient angle applied to the detection angle information or processing angle information used for the determination by the uphill road determination means increases,
The control device for an automatic transmission according to claim 1, wherein the clutch engagement pressure is reduced as the braking force increases. The control device for an automatic transmission according to claim 1 or 2, wherein the control means puts the clutch into an engaged state when the control condition is not satisfied. The road surface gradient angle detecting means includes
A longitudinal acceleration sensor for detecting longitudinal acceleration of the vehicle;
When the vehicle stops, the detection angle information is detected from the longitudinal acceleration detected by the longitudinal acceleration sensor based on the correspondence relationship between the longitudinal acceleration of the vehicle and the gradient angle,
When the vehicle is running, based on the vehicle longitudinal acceleration and the correspondence relationship between the braking force and the gradient angle, the longitudinal acceleration detected by the longitudinal acceleration sensor and the braking force detected by the braking force detecting means The control device for an automatic transmission according to any one of claims 1 to 3, wherein detection angle information is detected.

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