JP5625753B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device in which a torque converter with a lockup clutch is provided between an internal combustion engine and a transmission.

  Generally, a lockup clutch is mounted on many vehicles as a mechanical connection (hereinafter simply referred to as a direct connection) of an input side member and an output side member of a torque converter. When the lockup clutch is directly connected, the torque output from the internal combustion engine is directly transmitted to the transmission without passing through the fluid. Thereby, in the direct connection state of a lockup clutch, the transmission efficiency can be improved compared with the case where motive power is transmitted via a fluid.

  Further, in a vehicle equipped with such a torque converter with a lock-up clutch, not only the lock-up clutch is completely engaged, but also the lock-up clutch is slip-engaged under predetermined driving conditions, for example, when the vehicle starts. There has been proposed a control device that improves fuel efficiency by performing slip control (hereinafter, slip control at the time of vehicle start is referred to as slip start control).

  In a vehicle control apparatus that executes such slip start control, for example, a lock is used to bring the actual engine speed close to the target engine speed set in consideration of fuel consumption (hereinafter simply referred to as the optimum target engine speed). Feed forward control or feedback control is executed for the up clutch hydraulic pressure.

  In the feedforward control, the control amount based on the target value is calculated without detecting the deviation between the actual engine speed and the optimum target engine speed, so that the control response of the lockup clutch can be improved. Have advantages. However, when feedforward control is executed, the lockup clutch hydraulic pressure becomes higher than necessary during slip start control due to variations caused by individual differences in the lockup clutch itself and individual differences such as the solenoid controlling the engagement pressure of the lockup clutch. The actual engine speed may be significantly lower than the optimum target engine speed. As a result, in feed-forward control during slip start control, problems such as engagement shock due to excess lock-up clutch hydraulic pressure and engine stall due to decrease in actual engine rotation speed are caused, and drivability is deteriorated. There was a problem.

  On the other hand, as a vehicle control device that executes feedback control during slip start control, the optimum target engine speed is directly compared with the actual engine speed, and the actual engine speed is determined based on the comparison result. There has been proposed a feedback control of the lock-up clutch hydraulic pressure so as to follow (see, for example, Patent Document 1). According to the vehicle control device described in Patent Document 1, it is possible to suppress the occurrence of engagement shock by causing the actual engine rotation speed to follow the optimum target engine rotation speed during the slip start control.

  Further, in the vehicle control device described in Patent Document 1, by performing feedback control, the lock caused by individual differences of the lockup clutch itself and individual differences such as a solenoid for controlling the engagement pressure of the lockup clutch is achieved. Variations in the engagement pressure of the up clutch can be absorbed.

JP 2010-164092 A

  However, in the vehicle control device described in Patent Document 1, there is a possibility that hunting of the actual engine speed occurs when the vehicle starts due to the feedback control as described above. Specifically, in the vehicle control apparatus described in Patent Document 1, when the actual engine rotation speed falls below the optimum target engine rotation speed during slip start control because the engagement force of the lockup clutch is large, the actual engine rotation speed is reduced. In order to increase the speed, the lockup clutch hydraulic pressure is reduced by feedback control to reduce the engagement force of the lockup clutch. However, since the actual engine rotation speed at the time of starting the vehicle increases as the turbine rotation speed increases, if the engagement force of the lock-up clutch is further reduced by feedback control without considering this, the optimum target engine rotation speed It will rise more than necessary beyond. When the actual engine speed increases in this way, feedback control is executed to reduce the actual engine speed that has increased more than necessary. As described above, in the vehicle control apparatus described in Patent Document 1, there is a possibility that hunting of the actual engine rotation speed may occur during the slip start control. Therefore, the vehicle control device described in Patent Document 1 also has a problem that drivability deteriorates.

  The present invention has been made to solve the above-described conventional problems, and provides a vehicle control device that can improve drivability during slip control of a lock-up clutch when starting the vehicle. Objective.

In order to achieve the above object, a vehicle control apparatus according to the present invention includes: (1) an internal combustion engine, a transmission, and a torque converter with a lock-up clutch provided between the internal combustion engine and the transmission. A control device for a mounted vehicle, wherein an actual rotation speed detection unit that detects an actual rotation speed indicating an actual rotation speed of the internal combustion engine, and the lock-up clutch is released based on the state of the vehicle; A lockup control unit that executes any one of a normal control to be in an engaged state and a slip control to be in a slip state between the released state and the engaged state, and the lockup control unit includes: When executing the slip control, a target rotational speed indicating a target value of the rotational speed of the internal combustion engine is set based on the state of the vehicle, and the actual rotational speed is made to coincide with the target rotational speed. Yo performs a feed-forward control and feedback control, the lock-up control unit during the execution of the slip control, the case where the actual rotational speed relative to the target rotational speed deviates more than a predetermined value, the The feed forward control and the feedback control are interrupted to maintain the slip state .

  With this configuration, when the slip control is executed, the vehicle control device according to the present invention performs the feedforward control and the feedback control so that the lockup control unit matches the actual rotation speed with the target rotation speed, and sets the target rotation speed. On the other hand, if the actual rotational speed deviates by more than a predetermined value, feed-forward control and feedback control are interrupted, so the amount of feed-forward control and feedback control increases when slip control is executed. It is possible to prevent problems such as the engagement shock of the up clutch, the engine stop accompanying the decrease in the actual rotational speed, and the hunting of the actual rotational speed. Therefore, the vehicle control apparatus according to the present invention can improve drivability during slip control.

  The vehicle control device according to the present invention is the vehicle control device according to (1), wherein (2) the lockup control unit performs the target rotation from the actual rotation speed when the slip control is executed. When the determination value obtained by reducing the speed falls below a predetermined first threshold value, the feedforward control and the feedback control are interrupted.

  With this configuration, when the slip control is executed, the vehicle control apparatus according to the present invention has a lockup control unit when the determination value obtained by subtracting the target rotation speed from the actual rotation speed falls below a predetermined first threshold value. Since the feedforward control and the feedback control are interrupted, it is possible to prevent the engagement force of the lockup clutch from being increased more than necessary by the feedforward control when the slip control is executed. For this reason, the vehicle control apparatus according to the present invention can prevent problems such as an engagement shock of the lockup clutch at the time of executing the feedforward control and an engine stop due to a decrease in the actual rotation speed. On the other hand, since the vehicle control apparatus according to the present invention also interrupts the feedback control as described above, the actual rotational speed does not rise more than necessary when the slip control is executed, and the actual rotational speed hunting by the feedback control is performed. Can be prevented. Therefore, the vehicle control apparatus according to the present invention can improve drivability during slip control.

  The vehicle control device according to the present invention is the vehicle control device according to (1) or (2), wherein (3) the slip control is slip start control that is executed when the vehicle starts. It has a configuration.

  With this configuration, the slip control executed in the vehicle control device according to the present invention is the slip start control executed when the vehicle starts, and therefore the actual rotational speed that appears prominently during the slip start control when the vehicle starts is necessary. It is possible to prevent the above-described decrease and the actual rotational speed from rising.

  The vehicle control device according to the present invention is the vehicle control device according to any one of (1) to (3) described above. (4) The vehicle locks up the hydraulic pressure according to the calculated hydraulic pressure command value. A hydraulic control unit that controls an engagement force of the lockup clutch by supplying the clutch to the clutch; the lockup control unit calculates the hydraulic pressure command value in the feedforward control and the feedback control; When the control and the feedback control are interrupted, the hydraulic pressure command value calculated last time is held.

  With this configuration, the vehicle control device according to the present invention calculates the hydraulic pressure command value in the feedforward control and the feedback control, and the lockup control unit calculates the hydraulic pressure command previously calculated when the feedforward control and the feedback control are interrupted. Since the value is maintained, it is possible to suppress a change in the engagement force of the lockup clutch.

  Further, the vehicle control device according to the present invention is the vehicle control device according to any one of (2) to (4), wherein (5) the lock-up control unit is configured such that the determination value is a predetermined second value. When it becomes more than a threshold value, it has the structure which restarts the said feedforward control and said feedback control which were interrupted.

  With this configuration, the control apparatus for a vehicle according to the present invention is configured so that when the determination value obtained by subtracting the target rotational speed from the actual rotational speed is equal to or greater than the second threshold, Since the feedback control is resumed, if it can be determined that the drivability during the slip control is not affected even if the feedforward control and the feedback control are resumed, the actual rotational speed is set to the target rotational speed by the feedforward control and the feedback control. Can be accurately followed.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the vehicle which can improve the drivability at the time of slip control of the lockup clutch at the time of vehicle start can be provided.

It is a schematic block diagram of the power train of the vehicle which concerns on embodiment of this invention. It is a functional block diagram of the control device of the vehicle concerning an embodiment of the invention. It is an LU area map showing a lockup area. It is an optimal fuel consumption map used for the setting of the optimal target engine speed. It is a processing flow of slip start control performed by ECU which concerns on embodiment of this invention. It is a timing chart at the time of start of the vehicle concerning an embodiment of the invention. It is a timing chart at the time of start of the conventional vehicle which performs only feedforward control at the time of slip start control. It is a timing chart at the time of start of the conventional vehicle which performs feedforward control and feedback control at the time of slip start control.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the present embodiment, a case will be described in which the vehicle control device according to the present invention is applied to a vehicle in which a torque converter with a lockup clutch is mounted between an internal combustion engine such as an engine and a transmission. The vehicle control apparatus according to the present invention is also applicable to a so-called hybrid vehicle that further includes a driving force source such as a motor in addition to the engine. In the present embodiment, an example in which a continuously variable transmission (hereinafter simply referred to as CVT) is adopted as a transmission will be described. However, the transmission is not limited to a continuously variable transmission, and a stepped transmission. It may be.

  First, referring to FIG. 1, a power train of a vehicle equipped with a control device according to an embodiment of the present invention will be described.

  As shown in FIG. 1, the power train 10 includes an engine 1 as an internal combustion engine, a torque converter 2, a forward / reverse switching device 3, a CVT 4, a differential gear 5, a hydraulic control unit 100, an electronic control unit ( (Electronic Control Unit: hereinafter simply referred to as ECU) 200.

  As the engine 1, a known power device that outputs power by burning a mixture of hydrocarbon fuel such as gasoline or light oil and air in a combustion chamber of a cylinder (not shown) is used. The engine 1 reciprocates the piston in the cylinder by repeatedly performing a series of steps of intake, compression, combustion, and exhaust of the air-fuel mixture in the combustion chamber, and serves as an output shaft connected to the piston so as to be able to transmit power. The crankshaft (not shown) is rotated. A crankshaft of the engine 1 is connected to the input shaft of the torque converter 2. The output of the engine 1 is transmitted from the crankshaft and the torque converter 2 to the differential gear 5 via the forward / reverse switching device 3, the input shaft 4a, and the CVT 4, and is distributed to the left and right drive wheels (not shown).

  The torque converter 2 includes a pump impeller 21p connected to the crankshaft of the engine 1 and a turbine impeller 21t connected to the forward / reverse switching device 3 via the turbine shaft 2a, and transmits power through the fluid. To do.

  A lockup clutch 22 is provided between the pump impeller 21p and the turbine impeller 21t of the torque converter 2. Further, an engagement side oil chamber 24 and a release side oil chamber 25 divided by the piston 23 are formed inside the torque converter 2. The lockup clutch 22 is engaged or released when the hydraulic pressure supply to the engagement side oil chamber 24 and the release side oil chamber 25 is switched by a switching valve of the hydraulic control unit 100 described later. Specifically, assuming that a value obtained by subtracting the hydraulic pressure in the disengagement side oil chamber 25 from the hydraulic pressure in the engagement side oil chamber 24 is a hydraulic pressure difference ΔP, the piston 23 supplies the hydraulic pressure to the engagement side oil chamber 24. Accordingly, when the hydraulic pressure difference ΔP is increased, it moves to the engagement side. As a result, the lock-up clutch 22 is pressed to the pump impeller 21p side and fully engaged. As a result, the pump impeller 21p on the input shaft side and the turbine impeller 21t on the output shaft side are directly connected. That is, the crankshaft of the engine 1 and the turbine shaft 2a are directly connected. At this time, the power output from the engine 1 is directly transmitted to the CVT 4 without passing through the fluid in the torque converter 2.

  On the other hand, when the hydraulic pressure difference ΔP is a negative value, the piston 23 moves to the release side. As a result, the lockup clutch 22 is released. At this time, the power output from the engine 1 is transmitted to the CVT 4 via the fluid.

  Further, when the hydraulic pressure difference ΔP is in a range between the value at the time of direct connection and the value at the time of release, the lockup clutch 22 is in a slip state. In this slip state, the sum of the torque transmitted by the torque converter 2 and the torque transmitted by the lockup clutch 22 is transmitted to the turbine impeller 21t on the output shaft side.

  The pump impeller 21p is provided with an oil pump 26 that operates in accordance with the rotation of the pump impeller 21p. The oil pump 26 is configured by a mechanical oil pump such as a gear pump, for example, and supplies hydraulic pressure to various solenoids of the hydraulic control unit 100.

  The forward / reverse switching device 3 is provided in a power transmission path between the torque converter 2 and the CVT 4 and is mainly composed of a double pinion type planetary gear device. Further, the forward / reverse switching device 3 includes a forward clutch C1 and a reverse brake B1 that are configured by a hydraulic friction engagement device that is frictionally engaged by a hydraulic cylinder. The forward / reverse switching device 3 is brought into an integral rotation state by engaging the forward clutch C1 and releasing the reverse brake B1. At this time, the forward power transmission path is established, and the forward driving force is transmitted to the CVT 4 side. On the other hand, when the reverse brake B1 is engaged and the forward clutch C1 is released, the forward / reverse switching device 3 sets the reverse power transmission path for rotating the input shaft 4a in the reverse direction with respect to the turbine shaft 2a. Establish. Thereby, the driving force in the reverse direction is transmitted to the CVT 4 side. Further, when both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 3 is set to a neutral (interrupted state) state that interrupts power transmission.

  The CVT 4 includes an input-side primary pulley 41 having a variable effective diameter, an output-side secondary pulley 42 having a variable effective diameter, and a metal transmission belt 43 wound around these pulleys. The CVT 4 transmits power via a friction force between a primary pulley 41 provided on the input shaft 4a and a secondary pulley 42 provided on the output shaft 4b and the transmission belt 43.

  The primary pulley 41 and the secondary pulley 42 are fixed to the input shaft 4a and the output shaft 4b, respectively, and fixed to the input shaft 4a and the output shaft 4b. A movable sheave 41b and a movable sheave 42b are provided so as to be movable. The transmission belt 43 is wound around a V-shaped pulley groove formed by the fixed sheave and the movable sheave. Moreover, the primary pulley 41 and the secondary pulley 42 have a hydraulic actuator (not shown) for moving the movable sheaves 41b and 42b in the axial direction. The primary pulley 41 and the secondary pulley 42 continuously change the width of the pulley groove by controlling the hydraulic pressure supplied to the hydraulic actuator. Thereby, the winding radius of the transmission belt 43 is changed, and the transmission gear ratio is continuously changed.

  The hydraulic control unit 100 includes a shift speed control unit 110, a belt clamping pressure control unit 120, a line pressure control unit 130, a lockup engagement pressure control unit 140, a clutch pressure control unit 150, and a manual valve 160. Have.

  The shift speed control unit 110 controls the hydraulic pressure supplied to the hydraulic actuator of the primary pulley 41 in accordance with the hydraulic pressure output from the first shift control solenoid 111 and the second shift control solenoid 112. That is, the transmission speed control unit 110 controls the transmission ratio of the CVT 4 through hydraulic pressure control.

  The belt clamping pressure control unit 120 controls the hydraulic pressure supplied to the hydraulic actuator of the secondary pulley 42 according to the hydraulic pressure output from the belt clamping pressure control linear solenoid 121. That is, the belt clamping pressure control unit 120 controls the belt clamping pressure through the control of the hydraulic pressure.

  The line pressure control unit 130 controls the line pressure according to the hydraulic pressure output from the line pressure control linear solenoid 131. The line pressure refers to the hydraulic pressure supplied by the oil pump 26 and regulated by a regulator valve (not shown).

  The lockup engagement pressure control unit 140 controls the hydraulic pressure difference ΔP described above in accordance with the hydraulic pressure output from the lockup engagement pressure control linear solenoid 141, so that the engagement force of the lockup clutch 22, that is, the transmission torque. To control. The lockup clutch 22 is controlled to any one of a released state, an engaged state, and a slip state (an intermediate state between the released state and the engaged state) according to the magnitude of the transmission torque. The transmission torque of the lockup clutch 22 becomes a minimum value in the released state, increases as the hydraulic pressure difference ΔP is increased in the slip state, and reaches a maximum value in the engaged state.

  The manual valve 160 operates in conjunction with the operation of the shift lever by the driver, and switches the oil passage.

  The clutch pressure control unit 150 controls the hydraulic pressure supplied from the manual valve 160 to the input clutch C1 or the reverse brake B1 in accordance with the hydraulic pressure output from the line pressure control linear solenoid 131.

  The ECU 200 includes a vehicle speed sensor 201 that detects the vehicle speed V, an accelerator pedal operation amount, that is, an accelerator opening sensor 202 that detects the accelerator opening Acc, and the rotational speed of the pump impeller 21p to which the rotation of the engine 1 is transmitted. An engine rotational speed sensor 203 that detects the rotational speed, a turbine rotational speed sensor 204 that detects a rotational speed of the turbine shaft of the torque converter 2, that is, a turbine rotational speed Nt, a primary pulley rotational speed sensor 205, a secondary pulley rotational speed sensor 206, etc. Various sensors are connected via a harness or the like. The primary pulley rotation speed sensor 205 detects the rotation speed of the primary pulley 41, that is, the primary pulley rotation speed Nin. The secondary pulley rotational speed sensor 206 detects the rotational speed of the secondary pulley 42, that is, the secondary pulley rotational speed Nout. Detection signals indicating the detection results of these sensors are input from each sensor to ECU 200. The engine rotation speed sensor 203 in the present embodiment constitutes an actual rotation speed detection unit according to the present invention.

  ECU 200 outputs a control signal (hydraulic command value) to each solenoid of hydraulic control unit 100 based on the detection signals input from the sensors. Thereby, the hydraulic pressure output from each solenoid is adjusted. In particular, the ECU 200 calculates a hydraulic pressure command value Pl of the lockup engagement pressure control linear solenoid 141 in order to set the lockup clutch 22 during slip start control to a desired transmission torque by feedforward control and feedback control described later. , This is to be output.

  In the present embodiment, ECU 200 controls the state of lockup clutch 22 to be any of an engaged state, a released state, and a slip state, depending on the traveling state of the vehicle. Specifically, the ECU 200 determines in which region the vehicle is running based on an LU region map (see FIG. 3) indicating the relationship between the accelerator opening degree Acc and the vehicle speed V stored in the storage unit 230 in advance. And the lock-up clutch 22 is controlled to one of the engaged state, the released state, and the slip state according to the region. The determination of which region the vehicle is in may be performed using a map that shows the relationship between the throttle opening θth and the vehicle speed V.

  In addition, the ECU 200 is configured to execute slip control that causes the lockup clutch 22 to slip. This slip control is also called flex lockup control or the like, and is control executed for the purpose of improving the fuel consumption as much as possible without impairing drivability. The slip control is executed only when the running state of the vehicle is in the slip region based on the LU region map (see FIG. 3). In the present embodiment, the slip control is executed particularly when the vehicle starts. Therefore, in the following description, slip control (hereinafter referred to as slip start control) when starting the vehicle will be mainly described.

  During the slip start control, the ECU 200 controls the lockup engagement pressure control unit 140 so as to increase or decrease the above-described hydraulic pressure difference ΔP in a range between the value at the time of engagement of the lockup clutch 22 and the value at the time of release. Thus, the lock-up clutch 22 is controlled to the slip state.

  Next, with reference to FIG. 2, details of the ECU 200 that executes the slip start control will be described. Each functional block shown in FIG. 2 shows only those that function when the slip start control is executed.

  As shown in FIG. 2, ECU 200 includes an input I / F 210, an arithmetic processing unit 220, a storage unit 230, and an output I / F 240.

  A detection signal from each sensor is input to the input I / F 210. Then, the input I / F 210 outputs the input detection signal to the arithmetic processing unit 220.

The storage unit 230 includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The storage unit 230 is used for determining various information, programs, feedforward control, feedback control interruption, and restart. Various thresholds such as a threshold th ₁ and a second threshold th ₂ , various maps such as an LU region map and an optimum fuel consumption map are stored. The storage unit 230 reads and stores data from the arithmetic processing unit 220 as necessary.

  The arithmetic processing unit 220 is configured by a so-called CPU (Central Processing Unit), and uses the temporary storage function of the RAM of the storage unit 230 and performs signal processing according to a program stored in advance in the ROM.

  The arithmetic processing unit 220 includes a condition determination unit 221, a target rotation speed calculation unit 222, a target rotation speed initial value setting unit 223, a rotation speed comparison unit 224, an FF / FB control determination unit 225, and a lockup. And a hydraulic control unit 226. In the present embodiment, the ECU 200 having the arithmetic processing unit 220 constitutes a lockup control unit according to the present invention.

  The condition determination unit 221 determines whether the start condition and the end condition of the slip start control are satisfied. Specifically, the condition determination unit 221 determines whether the current traveling state of the vehicle is included in the engagement region, the release region, or the slip region based on the LU region map illustrated in FIG. It is like that. Here, the condition determination unit 221 determines that the vehicle running state is in the slip region, the accelerator is turned on, and the turbine rotational speed Nt changes from a value smaller than a predetermined threshold value to a larger value, that is, vehicle start. If it is time, it is determined that the start condition of the slip start control is satisfied. The condition determination unit 221 may determine that the vehicle is starting when it is detected that the accelerator opening Acc, the throttle opening θth, or the like has increased from zero.

  On the other hand, based on the LU area map, the condition determination unit 221 determines that the condition for ending the slip start control is satisfied when the running state of the vehicle during the slip start control shifts from the slip area to the engagement area or the release area. It is supposed to be. Here, as an example of shifting to the engagement region, during the slip start control, the turbine rotation speed Nt and the engine rotation speed Ne are substantially synchronized with the turbine rotation speed Nt exceeding a predetermined threshold. Can be mentioned. Further, as an example of shifting to the release region, there is a case where the vehicle is stopped or in a state immediately before being stopped, that is, a case where the vehicle speed V becomes smaller than a predetermined threshold.

The target rotational speed calculation unit 222 calculates and sets a target engine rotational speed in consideration of fuel consumption (hereinafter referred to as an optimal target engine rotational speed Netgt ₀ ) according to the vehicle speed V and the accelerator opening Acc. Yes. That is, the target rotational speed calculation unit 222 sets the optimal target engine rotational speed Netgt ₀ using the optimal fuel efficiency map (see FIG. 4) indicating the fuel efficiency optimal line. In FIG. 4, the vertical axis indicates the engine torque Te, the horizontal axis indicates the engine rotational speed Ne, and the fuel efficiency optimal line L2 is obtained by experimentally obtaining in advance a combination of the engine rotational speed Ne and the engine torque Te at which the fuel efficiency is optimal. It is a connected line. A specific method for setting the optimum target engine speed Netgt ₀ is as follows.

First, the target rotational speed calculation unit 222 calculates a target engine output required by the driver based on the vehicle speed V and the accelerator opening Acc. At this time, if the vehicle speed V is the same, the target engine output is calculated as a larger value as the accelerator opening Acc is larger. Next, the target rotational speed calculation unit 222 calculates a target engine rotational speed that achieves the target engine output with optimum fuel consumption. Specifically, an equal output line L1 that sets the set target engine output (engine rotation speed Ne × engine torque Te) constant is set on the optimum fuel consumption map. Therefore, the equal output line L1 moves to the upper right side of FIG. 4 as the target engine output increases, and moves to the lower left side of FIG. 4 as the target engine output decreases. Then, the target rotational speed calculation unit 222 obtains an intersection A between the iso-output line L1 and the optimal fuel efficiency line L2 on the optimal fuel efficiency map, and determines the engine rotational speed Ne corresponding to the intersection A as the optimal target engine rotational speed Netgt _0. Calculate as Note that the optimum target engine speed Netgt ₀ may be calculated by another method.

Target rotational speed initial value setting unit 223, as shown in FIG. 6, the start condition of the slip start control is satisfied, the actual engine rotational speed when the lockup clutch 22 is shifted to the slip state (time t ₂ time) (Hereinafter referred to as the actual engine speed Ner) is set as an initial value of the target engine speed Netgt ₁ . Here, the target engine speed Netgt ₁ is a target engine speed provided to prevent the output of feedback control from increasing when the deviation between the optimum target engine speed Netgt ₀ and the actual engine speed Ner is large. Is speed. The target engine speed Netgt ₁ is controlled so as to approach the optimum target engine speed Netgt ₀ after the initial value is set. Therefore, the target engine rotational speed Netgt ₁ eventually coincides with the optimum target engine rotational speed Netgt ₀ . After matching with the optimal target engine speed Netgt ₀ , target engine speed Netgt ₁ = optimal target engine speed Netgt ₀ . The target engine rotational speed Netgt ₁ in the present embodiment corresponds to a target rotational speed indicating a target value of the rotational speed of the internal combustion engine in the present invention. Further, the actual engine rotation speed Ner in the present embodiment corresponds to the actual rotation speed in the present invention.

The rotational speed comparison unit 224 compares the actual engine rotational speed Ner detected by the engine rotational speed sensor 203 with the target engine rotational speed Netgt ₁ and calculates a deviation ΔNe (= | Ner−Netgt ₁ |) as a comparison result. It outputs to the lock-up hydraulic pressure control unit 226. The deviation ΔNe is used for feedback control during slip start control. Further, the rotation speed comparison unit 224 calculates a value obtained by subtracting the target engine rotation speed Netgt ₁ from the actual engine rotation speed Ner as a determination value Nj (= Ner−Netgt ₁ ), and outputs the calculated value to the FF / FB control determination unit 225. It is designed to output. The determination value Nj determines whether or not to interrupt the feed-forward control and feedback control during slip start executed by the FF / FB control determination unit 225, and whether to resume the interrupted feed-forward control and feedback control. Used to determine whether or not. As the determination value Nj, a value obtained in the process of calculating the deviation ΔNe (= | Ner−Netgt ₁ |) may be used.

FF · FB control determining unit 225, whether the actual engine speed Ner the target engine rotational speed Netgt ₁ has deviated more than a predetermined value, in particular the actual engine speed Ner the target engine rotational speed Netgt ₁ given It is determined whether or not the value is lower than the value. Specifically, the FF / FB control determination unit 225 compares the determination value Nj input from the rotation speed comparison unit 224 with the first threshold th ₁ that is experimentally obtained and stored in advance, and determines the determination value Nj. There is adapted to determine whether the first is smaller than the threshold value th _1. Here, the first threshold th ₁ is when the actual engine rotational speed Ner falls below the target engine rotational speed Netgt ₁ to such an extent that it can be determined that the engagement force of the lockup clutch 22 has become larger than necessary during the slip start control. For example, a value of about −100 rpm. When the determination value Nj is determined to be larger than the first threshold th ₁ , the FF / FB control determination unit 225 outputs a signal instructing interruption of the feedforward control and the feedback control to the lockup hydraulic control unit 226. It is like that.

Also, FF · FB control determining unit 225 compares the second and the threshold th ₂ that is experimentally determined in advance and stored as the determination value Nj, or the determination value Nj becomes the second threshold th ₂ or not It is to judge whether. Here, the second threshold th ₂ is set so that the actual engine rotational speed Ner can be determined to the extent that it can be determined that the drivability during the slip start control is not affected even if the suspended feedforward control and feedback control are resumed. This is the difference in rotational speed when the engine rotational speed Netgt ₁ is exceeded. FF · FB control determining unit 225, the determination value Nj is adapted to resume the feedforward control and feedback control is suspended when it is determined that the second threshold value th ₂ or more.

The lockup hydraulic pressure control unit 226 will be described later so that the actual engine rotational speed Ner matches (follows) the target engine rotational speed Netgt ₁ from when the slip start control start condition is satisfied until the slip start control end condition is satisfied. The hydraulic pressure command value Pl of the lockup engagement pressure control linear solenoid 141 is controlled using feedforward control and feedback control.

  In general, the control for causing the actual engine speed to follow the target engine speed includes feedback control based on a deviation between the target engine speed and the actual engine speed. However, in this feedback control, since a control amount is calculated by multiplying the deviation by a predetermined gain, it is executed when the deviation occurs, and there is an inevitable control delay because it is assumed that the deviation occurs. In order to correct such a delay, it is conceivable to increase the gain. However, if the gain is excessively increased, inconveniences such as hunting or a decrease in convergence occur. Therefore, in the present embodiment, feedforward control is used in combination with feedback control. Since the feedforward control calculates the control amount based on the target value, the control can be executed without waiting for the detection of the deviation, and is excellent in terms of responsiveness.

Specifically, when the start condition of the slip start control is satisfied, the lockup hydraulic pressure control unit 226 uses a map and an arithmetic expression (not shown) that are experimentally obtained and stored in advance based on the engine torque Te and the vehicle speed V. A feedforward control amount (hereinafter simply referred to as FF control amount) ΔP _FF is calculated. At the same time, the lock-up hydraulic pressure control unit 226 multiplies the deviation ΔNe between the actual engine speed Ner and the target engine speed Netgt ₁ by a predetermined feedback gain K, thereby providing a feedback control amount (hereinafter simply referred to as an FB control amount). ) ΔP _FB (= K × ΔNe) is calculated. Here, the feedback gain K is a positive constant. As a method for calculating the FB control amount ΔP _FB , for example, a method of using a PID feedback control equation can be cited. The lock-up pressure control unit 226, based on the calculated value obtained by adding the FF control amount [Delta] P _FF and FB control amount [Delta] P _FB, controls the hydraulic pressure command value Plu of the lock-up engagement pressure control linear solenoid 141 . In the present embodiment, when the hydraulic pressure command value Pl is increased, the hydraulic pressure difference ΔP of the lockup clutch 22 is increased. Conversely, when the hydraulic pressure command value Pl is decreased, the hydraulic pressure difference ΔP of the lockup clutch 22 is increased. It has come to decrease.

For example, when the actual engine rotation speed Ner is lower than the target engine rotation speed Netgt ₁ , the lockup oil pressure control unit 226 decreases the oil pressure command value Pl by a predetermined value in order to reduce the oil pressure difference ΔP. By reducing the hydraulic pressure command value Plu by a predetermined value, the transmission torque of the lockup clutch 22 is reduced and the load applied to the engine 1 is reduced. Therefore, the actual engine rotation speed Ner increases and approaches the target engine rotation speed Netgt ₁ . It will be. On the other hand, when the actual engine rotational speed Ner is higher than the target engine rotational speed Netgt ₁ , the lockup hydraulic pressure control unit 226 increases the hydraulic pressure command value Pl by a predetermined value in order to increase the hydraulic pressure difference ΔP. By increasing the hydraulic pressure command value Pl by a predetermined value, the transmission torque of the lockup clutch 22 increases and the load applied to the engine 1 increases, so the actual engine speed Ner decreases and the target engine speed Netgt ₁ is reached. It will approach.

  By the way, in the conventional slip start control, the target slip amount is calculated using the turbine rotational speed Nt, and the slip amount of the torque converter 2 is made to follow the target slip amount. However, since the turbine rotation speed Nt is greatly affected by detection errors due to noise and the like, driver operations (brake, gear shifting), and changes in the driving environment such as the road surface, the target slip amount is originally set as the target. It deviates from the power value. As a result, the slip amount of the torque converter 2 may deviate from a value that should originally be the target.

In contrast, ECU 200 according to this embodiment, an actual engine rotational speed Ner and the target engine rotational speed Netgt ₁ compares directly the actual engine rotational speed Ner on the basis of the comparison result to the target engine rotational speed Netgt ₁ The hydraulic pressure command value Pl is feedback controlled so as to follow. Therefore, in the present embodiment, the feedback control of the hydraulic pressure command value Pl is performed without using the turbine rotational speed Nt, which can be a factor that deteriorates the control accuracy. The target engine speed Netgt ₁ can be followed more accurately.

  Further, when the slip start control end condition is satisfied, the lockup hydraulic pressure control unit 226 performs normal control for controlling the lockup clutch 22 to either the released state or the engaged state according to the traveling state of the vehicle. It is like that. Specifically, the lockup hydraulic pressure control unit 226 sets the hydraulic pressure command value Pl to the maximum value when the traveling state of the vehicle is included in the engagement region based on the LU region map shown in FIG. By setting the hydraulic pressure command value Pl to the maximum value, the hydraulic pressure difference ΔP becomes maximum, and the lockup clutch 22 is engaged. On the other hand, the lockup hydraulic pressure control unit 226 sets the hydraulic pressure command value Pl to the minimum value when the traveling state of the vehicle is included in the release area based on the LU area map. By setting the hydraulic pressure command value Pl to the minimum value, the hydraulic pressure difference ΔP becomes a negative value, and the lockup clutch 22 is released.

The lock-up hydraulic pressure control unit 226 calculates the transmission torque of the lock-up clutch 22 required to make the actual engine speed Ner coincide with the target engine speed Netgt ₁ , and is experimentally obtained and stored in advance. The hydraulic pressure command value Pl may be controlled according to the calculated transmission torque from a map or a relational expression showing the relationship between the transmission torque and the hydraulic pressure command value Pl.

  Next, the slip start control executed by the ECU 200 will be described with reference to FIGS.

  The processing flow shown in FIG. 5 is repeatedly executed at a predetermined cycle time. In addition, each processing is actually a condition determination unit 221, a target rotation speed calculation unit 222, a target rotation speed initial value setting unit 223, a rotation speed comparison unit 224, and an FF / FB control determination that are included in the arithmetic processing unit 220 of the ECU 200. This process is executed by either the unit 225 or the lockup hydraulic pressure control unit 226. In the following, for convenience of explanation, the main body of each process will be described as the ECU 200.

  First, ECU 200 determines whether or not a start condition for slip start control is satisfied (step S1). Specifically, ECU 200 is based on vehicle speed V, accelerator opening degree Acc, and LU area map shown in FIG. 3, and whether the current vehicle running state is included in the engagement area, the release area, or the slip area. Determine whether or not. At the same time, the ECU 200 determines whether the current vehicle running state is in the slip region, the accelerator is turned on, and the turbine rotational speed Nt changes from a value smaller than a predetermined threshold value to a larger value, that is, when the vehicle starts. Determine whether or not. At this time, ECU 200 determines that the start condition of the slip start control is satisfied when it is determined that the current traveling state of the vehicle is in the slip region and the vehicle is starting.

  Note that the ECU 200 may detect the vehicle speed V based on the secondary pulley rotational speed Nout input from the secondary pulley rotational speed sensor 206 instead of the vehicle speed V input from the vehicle speed sensor 201.

  When it is determined that the start condition for the slip start control is not satisfied, the ECU 200 moves the process to step S9 and executes the normal control of the lockup clutch 22. For example, when the current running state of the vehicle is in the engagement region, the lock-up clutch 22 is engaged, and when the current traveling state of the vehicle is in the release region, the lock-up clutch 22 is released.

On the other hand, when it is determined that the start condition of the slip start control is satisfied, the ECU 200 determines the vehicle speed V, the accelerator opening based on the detection signals input from the vehicle speed sensor 201, the accelerator opening sensor 202, and the engine rotation speed sensor 203. Acc and actual engine speed Ner are detected (step S2). That, ECU 200 detects the vehicle speed V, the accelerator opening Acc and the actual engine speed Ner at the time _{t 2} shown in FIG.

Next, the ECU 200 calculates and sets the optimum target engine speed Netgt ₀ based on the accelerator opening Acc and the vehicle speed V detected in step S2 (step S3). The specific setting method of the optimum target engine speed Netgt ₀ is as described above, and the description thereof is omitted here.

Next, after starting the slip start control, the ECU 200 sets an initial value of the target engine rotational speed Netgt ₁ that should actually follow the actual engine rotational speed Ner (step S4). Specifically, ECU 200, the actual engine speed Ner at the time _{t 2} shown in FIG. 6 detected in step S2, i.e. the target engine rotational speed Netgt the actual engine rotational speed Ner when the start condition of the slip start control is satisfied Set as the initial value of ₁ . The target engine speed Netgt ₁ is controlled to approach the optimum target engine speed Netgt ₀ after the initial value is set.

Here, in fact, the timing is determined that conditions for starting the slip start control is satisfied, between the timing of the reduction start of the actual engine rotational speed Ner shown in time t ₂ is a time difference. Therefore, ECU 200, it is preferable to estimate the actual engine rotational speed Ner at time t ₂ on the basis of the actual engine speed Ner the starting condition of the slip start control has detected at the timing determined to be satisfied. Specifically, the ECU 200 experimentally obtains and stores in advance a predetermined time T from when the start condition of the slip start control is satisfied until the lockup clutch 22 actually slips and the actual engine speed Ner starts to decrease. The actual engine speed Ner at time t ₂ is estimated based on the product of the differential value dNer / dT indicating the amount of change in the actual engine speed Ner when the start condition of the slip start control is satisfied and the predetermined time T. Another estimation method described above, ECU 200, the actual engine rotational speed at the time t ₂ the actual engine speed Ner when the value of the differential value DNER / dT calculated from time to time is turned from a positive value to a negative value It may be detected as Ner and used in step S4.

In the present embodiment, has been to estimate the actual engine rotational speed Ner at time t ₂ based on the actual engine speed Ner detected at satisfied the start condition of the slip start control is not limited thereto, e.g. The actual engine speed Ner may be detected again at the timing when the predetermined time T has elapsed since the start condition of the slip start control is satisfied.

Next, the ECU 200 calculates a value obtained by subtracting the target engine rotational speed Netgt ₁ from the actual engine rotational speed Ner as a determination value Nj (= Ner−Netgt ₁ ) (step S5). The ECU 200 detects the actual engine rotation speed Ner in this step, but the value detected in step S2 may be substituted.

Next, ECU 200 compares the first and the threshold th ₁ described above and the determination value Nj calculated in step S5, it is determined whether or not the determination value Nj is smaller than the first threshold th ₁ (step S6 ). That is, the ECU 200 determines whether or not the actual engine speed Ner has fallen below the target engine speed Netgt ₁ to such an extent that it can be determined that the engagement force of the lockup clutch 22 has become larger than necessary during the slip start control. If the ECU 200 determines that the determination value Nj is smaller than the first threshold th ₁ in this step, the ECU 200 sets the actual engine speed Ner as the target until the slip start control end condition is satisfied (YES in step S8). The hydraulic pressure command value Pl of the lockup engagement pressure control linear solenoid 141 is controlled using feedforward control and feedback control so as to follow the engine rotational speed Netgt ₁ (step S7). The feedforward control and feedback control in step S7 are repeatedly executed at a cycle time different from the cycle time of this processing flow until the end condition of the slip start control is satisfied.

Specifically, ECU 200 calculates FF control amount ΔP _FF and FB control amount ΔP _FB using the calculation method described above. Then, ECU 200 controls hydraulic pressure command value Plu based on a value obtained by adding calculated FF control amount ΔP _FF and FB control amount ΔP _FB . In particular, in the feedback control, the ECU 200 determines whether or not the actual engine rotational speed Ner is lower than the target engine rotational speed Netgt ₁ . As a result of this determination, when the actual engine speed Ner is lower than the target engine speed Netgt ₁ , the ECU 200 corrects the oil pressure command value Pl to decrease. That is, ECU 200 is based on FB control amount ΔP _FB calculated by K × ΔNe with respect to hydraulic pressure command value Pl (n−1) at the previous cycle time with respect to hydraulic pressure command value Pl (n−1) at the previous cycle time. Decrease by value. In other words, the ECU 200 calculates as Plu (n) = Plu (n−1) −K × ΔNe.

On the other hand, when the actual engine rotation speed Ner is not lower than the target engine rotation speed Netgt ₁ (including the case where Ner = Netgt ₁ ), the ECU 200 causes the actual engine rotation speed Ner to be higher than the target engine rotation speed Netgt _1. It is determined whether or not. If the result of this determination is that the actual engine speed Ner is higher than the target engine speed Netgt ₁ , the ECU 200 corrects the oil pressure command value Pl. That is, ECU 200 is based on FB control amount ΔP _FB calculated by K × ΔNe with respect to hydraulic pressure command value Pl (n−1) at the previous cycle time with respect to hydraulic pressure command value Pl (n−1) at the previous cycle time. Increase by value. In other words, the ECU 200 calculates as Plu (n) = Plu (n−1) + K × ΔNe. On the other hand, the determination result, the actual engine rotational speed Ner is if not higher than the target engine rotational speed Netgt _1, it can be determined that the actual engine rotational speed Ner and the target engine rotational speed Netgt ₁ match, Without performing the decrease correction or the increase correction as described above, the hydraulic pressure command value Pl (n-1) at the previous cycle time is calculated as the hydraulic pressure command value Pl (n) at the current cycle time.

  Then, the ECU 200 sets the hydraulic pressure command value Pl (n) calculated at the current cycle time to the hydraulic pressure command value Pl, and outputs it to the lockup engagement pressure control linear solenoid 141.

  Next, the ECU 200 determines whether or not the slip start control end condition is satisfied (step S8). When it is determined that the slip start control end condition is satisfied, the ECU 200 executes normal control for controlling the lockup clutch 22 to either the released state or the engaged state according to the traveling state of the vehicle. (Step S9), and a series of processing ends. On the other hand, if it is determined that the slip start control end condition is not satisfied, ECU 200 returns to step S5 and repeatedly executes the processes of steps S5 to S8.

Further, ECU 200, in step S6 described above, the determination value Nj is not smaller than the first threshold th _1, that is, when it is determined that the first threshold value th ₁ or more (NO in step S6), feed Forward control and feedback control are interrupted (step S10). Specifically, as shown in FIG. 6, when the actual engine speed Ner falls below the target engine speed Netgt ₁ until the ECU 200 can determine that the engagement force of the lockup clutch 22 has become larger than necessary ( At time t ₃ ), the feedforward control and the feedback control are interrupted. At this time, the ECU 200 sets the hydraulic pressure command value Pl (n) at the current cycle time as the hydraulic pressure command value Pl (n−1) calculated at the previous cycle time. In other words, while the feedforward control and the feedback control are interrupted (time t ₃ to time t ₄ shown in FIG. 6), the hydraulic pressure command value Pl (n−1) calculated at the previous cycle time is held. . Here, as shown in FIG. 6, in a transitional state until the turbine rotational speed Nt converges to a target value, particularly when the vehicle starts, the actual engine increases with the increase in the turbine rotational speed Nt. Since the rotational speed Ner also increases, the engagement force of the lockup clutch 22 does not increase more than necessary by maintaining the previous hydraulic pressure command value Pl (n−1) as described above.

Next, the ECU 200 calculates a determination value Nj during the interruption of the feedforward control and the feedback control (step S11). That is, in this step as well as step S5, the ECU 200 detects the actual engine speed Ner, and obtains a value obtained by subtracting the target engine speed Netgt ₁ from the actual engine speed Ner as a determination value Nj (= Ner−Netgt ₁ ).

Then, the ECU 200 compares the determination value Nj calculated in step S11 with the second threshold th ₂ described above, and determines whether or not the determination value Nj is equal to or greater than the second threshold th ₂ (step S12). . That is, the ECU 200 determines that the actual engine rotational speed Ner is equal to the target engine rotational speed Netgt ₁ until it can be determined that the drivability during the slip start control is not affected even if the suspended feedforward control and feedback control are resumed. Judge whether or not it exceeded. If the ECU 200 determines in this step that the determination value Nj is not greater than or equal to the second threshold th ₂ , that is, is smaller than the second threshold th ₂ , the ECU 200 returns to step S 10 and interrupts the feedforward control and feedback control. maintain.

On the other hand, when ECU 200 determines that determination value Nj is greater than or equal to second threshold th ₂ (YES in step S12), it returns to step S4 and repeats the processes in and after step S4. Specifically, as shown in FIG. 6, the ECU 200 determines the actual engine speed to such an extent that it can be determined that the drivability during the slip start control is not affected even if the suspended feedforward control and feedback control are resumed. When the speed Ner exceeds the target engine speed Netgt ₁ (time t ₄ ), the feedforward control and the feedback control are resumed. At this time, although the actual engine speed Ner the target engine rotational speed Netgt ₁ is not in greatly different, for example, as shown in FIG. 6, if slightly larger than, the ECU 200 is real in the time _{t 4} The engine speed Ner is reset as the initial value of the target engine speed Netgt ₁ . The time t ₄ later in Figure 6, the feed forward control and feedback control is resumed. For this reason, the previous hydraulic pressure command value Pl (n−1) held until then is changed to a new hydraulic pressure command value Pl calculated from the resumed feedforward control and feedback control. In FIG. 6, the hydraulic pressure command value Pl is displayed separately for the hydraulic pressure command value by feedforward control and the hydraulic pressure command value by feedback control. However, in actuality, a value obtained by adding the hydraulic pressure command values of both these controls is It is output as a hydraulic pressure command value Pl.

  As described above, in the slip start control according to the present embodiment, the engagement force of the lockup clutch 22 becomes larger than necessary by executing the control for interrupting the feedforward control and the feedback control as necessary. Is avoided.

  On the other hand, in the conventional slip start control, since the feed forward control and the control for interrupting the feedback control are not executed as necessary during the slip start control, the following problems occur.

For example, in the case where only the feedforward control is executed during the slip start control, as shown in FIG. 7, the actual engine speed Ner and the target engine speed Netgt _{1 at the} start time of the slip start control (time t ₂ ). The FF control amount ΔP _FF based on the predetermined target value is calculated without detecting the deviation ΔNe from the. However, in actuality, a hydraulic command value Pl larger than necessary may be output due to variations caused by individual differences between the lockup clutch and the lockup engagement pressure control linear solenoid. For this reason, the lockup clutch hydraulic pressure is increased more than necessary during the slip start control, and the actual engine rotational speed Ner may be significantly lower than the target engine rotational speed Netgt ₁ . As a result, in feed-forward control during slip start control, problems such as engagement shock due to excess lock-up clutch hydraulic pressure and engine stall due to decrease in actual engine speed Ner are caused and drivability deteriorates. There was a problem of letting.

Further, in the case of using both feedforward control and feedback control at the time of slip start control, as shown in FIG. 8, at the time of slip start control, since the engagement force of the lockup clutch is large, the actual engine rotational speed Ner is When the target engine speed Netgt ₁ is less than the target engine speed Netgt ₁ , the lockup clutch hydraulic pressure is reduced by feedback control to reduce the engagement force of the lockup clutch in order to increase the actual engine speed Ner. However, when the vehicle is started to execute the slip start control, the turbine rotational speed Nt increases, and accordingly, the actual engine rotational speed Ner also increases. For this reason, the actual engine rotation speed Ner at the time of starting the vehicle increases with the turbine rotation speed Nt. Therefore, if the engagement force of the lockup clutch is further reduced by feedback control without considering this, the target engine rotation speed It exceeds the speed Netgt ₁ and increases more than necessary. When the actual engine rotation speed Ner rises in this way, feedback control is executed to reduce the actual engine rotation speed Ner that has increased more than necessary. As a result, during slip start control, there has been a problem that hunting of the actual engine rotational speed Ner occurs and drivability deteriorates.

Thus, conventional slip start control shown in FIGS. 7 and 8, both the actual engine speed Ner largely deviates with respect to the target engine rotational speed Netgt ₁ during vehicle starting, in particular the target engine rotational speed Netgt ₁ On the other hand, the drivability was deteriorated by the fact that the actual engine speed Ner was significantly lower.

On the other hand, in the slip start control according to the present embodiment, conventionally, the feedforward control and the feedback control are interrupted before the actual engine rotational speed Ner greatly deviates from the target engine rotational speed Netgt ₁ . I try to avoid the problems I had.

As described above, the vehicle control apparatus according to the present embodiment executes the feedforward control and the feedback control so that the ECU 200 matches the actual engine speed Ner with the target engine speed Netgt ₁ when the slip start control is executed. When the determination value Nj falls below the _first threshold th ₁ from the value obtained by subtracting the target engine speed Netgt ₁ from the actual engine speed Ner, the feedforward control and the feedback control are interrupted, so the slip start control is executed. At this time, it is possible to prevent the engagement force of the lockup clutch 22 from being increased more than necessary by the feedforward control. For this reason, the vehicle control apparatus according to the present embodiment prevents problems such as an engine shock due to an engagement shock of the lockup clutch 22 or an unnecessarily decrease in the actual engine rotation speed Ner when the feedforward control is executed. can do. On the other hand, since the vehicle control apparatus according to the present embodiment also interrupts the feedback control as described above, the actual engine rotational speed Ner does not rise more than necessary when the slip start control is executed, and the feedback control is performed. Hunting of the actual engine speed Ner can be prevented. Therefore, the vehicle control apparatus according to the present embodiment can improve drivability during slip start control.

  The vehicle control apparatus according to the present embodiment interrupts the feedforward control and the feedback control as necessary in the slip start control executed at the start of the vehicle as described above, so the slip start at the start of the vehicle It is possible to prevent the actual engine rotation speed Ner from appearing significantly during control, and to prevent the actual engine rotation speed Ner from rising more than necessary.

  In addition, the vehicle control apparatus according to the present embodiment calculates the hydraulic pressure command value Pl in the feedforward control and the feedback control, and when the ECU 200 interrupts the feedforward control and the feedback control, the hydraulic pressure command value Pl previously calculated. Since (n-1) is held, it can suppress that the engagement force of the lockup clutch 22 changes.

Further, in the vehicle control apparatus according to the present embodiment, when the determination value Nj obtained by subtracting the target engine rotational speed Netgt ₁ from the actual engine rotational speed Ner becomes equal to or greater than the second threshold th ₂ , the ECU 200 is suspended. Feedforward control and feedback control are resumed.If it can be determined that restarting feedforward control and feedback control does not affect the drivability during slip start control, the feedforward control and feedback control The engine speed Ner can be made to follow the target engine speed Netgt ₁ with high accuracy.

In the present embodiment, the ECU 200 executes the slip start control of the lockup clutch 22 based on the target engine rotational speed Netgt ₁ with the actual engine rotational speed Ner at the start of the slip start control as an initial value. However, the present invention is not limited to this. For example, the slip start control may be executed based on the optimum target engine speed Netgt ₀ without setting the target engine speed Netgt ₁ . In this case, the hydraulic pressure command value Pl of the lockup engagement pressure control linear solenoid 141 is controlled using feedforward control and feedback control so that the actual engine rotational speed Ner follows the optimum target engine rotational speed Netgt _0. . In this case, the determination value Nj used for determining whether or not to interrupt the feedforward control and the feedback control is a value obtained by subtracting the optimum target engine speed Netgt ₀ from the actual engine speed Ner.

  Further, in the present embodiment and the above modification, the example in which the ECU 200 uses the feedforward control in addition to the feedback control has been described. However, the present invention is not limited thereto, and only the feedback control may be executed. Further, only the feedforward control may be executed.

  As described above, the vehicle control apparatus according to the present invention can improve the drivability during the slip control of the lockup clutch when the vehicle starts, and the lockup clutch is provided between the internal combustion engine and the transmission. This is useful for a vehicle control device provided with this torque converter.

1 engine (internal combustion engine)
2 Torque converter 4 CVT (transmission)
22 lockup clutch 100 hydraulic control unit 140 lockup engagement pressure control unit 141 linear solenoid for lockup engagement pressure control 200 ECU (lockup control unit)
203 Engine speed sensor (actual speed detector)

Claims (5)

A vehicle control device on which an internal combustion engine, a transmission, and a torque converter with a lockup clutch provided between the internal combustion engine and the transmission are mounted,
An actual rotation speed detecting unit for detecting an actual rotation speed indicating an actual rotation speed of the internal combustion engine;
Based on the state of the vehicle, either normal control for bringing the lock-up clutch into a released state or engaged state, or slip control for making a slip state between the released state and the engaged state is executed. A lock-up control unit,
When executing the slip control, the lockup control unit sets a target rotational speed indicating a target value of the rotational speed of the internal combustion engine based on the state of the vehicle, and sets the actual rotational speed to the target rotational speed. When the feedforward control and the feedback control are executed so that they coincide with each other, and the lockup control unit deviates from the target rotation speed by a predetermined value or more during the slip control. The vehicle control device is characterized in that the slip-state is maintained by interrupting the feedforward control and the feedback control.   The lockup control unit, when executing the slip control, if a determination value obtained by subtracting the target rotational speed from the actual rotational speed falls below a predetermined first threshold value, the feedforward control and the feedback control The vehicle control device according to claim 1, wherein:   3. The vehicle control device according to claim 1, wherein the slip control is slip start control that is executed when the vehicle starts. The vehicle includes a hydraulic pressure control unit that controls an engagement force of the lockup clutch by supplying a hydraulic pressure corresponding to the calculated hydraulic pressure command value to the lockup clutch,
The lockup control unit calculates the hydraulic pressure command value in the feedforward control and the feedback control, and holds the hydraulic pressure command value calculated last time when the feedforward control and the feedback control are interrupted. The vehicle control device according to any one of claims 1 to 3.   5. The lockup control unit resumes the interrupted feedforward control and feedback control when the determination value is equal to or greater than a predetermined second threshold value. 6. The vehicle control device according to claim 1.

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