JP2002013623A - Speed change controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed change controller for automatic transmission, capable of reducing the load in acceleration control and braking operation by a driver in quick acceleration and deceleration, regardless of the distance between cars with respect to front vehicle in the presence of the front vehicle during traveling. SOLUTION: In this speed change controller for the automatic transmission, comprising a gear change ratio control means for determining the speed change target value from a driving point, determined on the basis of at least a throttle opening and a speed, and controlling the gear change ratio of the automatic transmission, a distance between cars detecting means is mounted for detecting a distance between a self-vehicle and the leading vehicle in the vehicle-advancing direction, a length of distance between cars judging means is mounted for judging the length of the distance between cars detected by the distance between car-detecting means, the speed change target value is determined to control the gear change ratio at a high side, and the shorter the distance between cars is judged by the length of distance between car judging means, the lower the side will be for change gear ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in a shift control device of an automatic transmission for a vehicle, a shift control is performed based on a running condition, a vehicle speed, an accelerator opening, an engine speed, and the like.

[0003]

However, in a conventional shift control device for an automatic transmission, for example, during traveling,
Regardless of the length of the inter-vehicle distance to a vehicle traveling ahead, the speed change control is performed under the above-described conditions.

That is, when the inter-vehicle distance is short, the acceleration force may be smaller than when the inter-vehicle distance is long. That is, for example, if the inter-vehicle distance with respect to the preceding vehicle is short, even if the preceding vehicle accelerates and the inter-vehicle distance increases, it is possible to follow the vehicle sufficiently without abrupt acceleration. On the other hand, at the time of deceleration, quick deceleration is required because the inter-vehicle distance is short. However, in the normal control, there is a problem that sufficient engine braking or the like is not applied, and the driver must perform accelerator control and brake operation with sufficient caution.

The present invention has been made in view of the above-mentioned problems and demands. In the case where a preceding vehicle is present during running, regardless of the distance between the vehicle and the preceding vehicle, an excessively high sensitivity is required. It is an object of the present invention to provide a shift control device for an automatic transmission that can reduce a burden caused by a driver's accelerator control due to deceleration and a brake operation.

[0006]

According to the first aspect of the present invention, there is provided a gear ratio control means for determining a gear shift target value based on at least an operating point determined by a throttle opening and a vehicle speed, and controlling a gear ratio of the automatic transmission. In a transmission control device for a transmission, an inter-vehicle distance detecting means for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle in a vehicle traveling direction is provided, and the length of the inter-vehicle distance detected by the inter-vehicle distance detecting means is determined. A distance length determination unit is provided, and the gear ratio control unit determines a gear shift target value such that the gear ratio becomes high when the headway distance determined by the headway distance determination unit is short, and determines that the headway distance is long. A shift control device for an automatic transmission, characterized in that the shift target value is determined so that the gear ratio becomes lower as the number of shifts increases.

According to a second aspect of the present invention, in the shift control device for an automatic transmission according to the first aspect, the automatic transmission is a continuously variable transmission that continuously controls a speed ratio. And

According to the third aspect of the present invention, the speed change of the automatic transmission is provided with a speed ratio control means for obtaining a speed change target value based on at least an operating point determined by the throttle opening and the vehicle speed and controlling the speed ratio of the automatic transmission. In the control device, the speed ratio control means, when controlling the speed ratio, if the inter-vehicle distance is short by the inter-vehicle distance length determination means, the speed is reduced,
A means for performing control to increase the shift speed as the inter-vehicle distance is determined to be longer is provided.

According to a fourth aspect of the present invention, in the shift control device for an automatic transmission according to the third aspect, when the shift control means performs a speed ratio control for increasing a shift speed,
A means for adding a correction line pressure to the normal line pressure is provided.

[0010]

According to a first aspect of the present invention, in the speed change control device for an automatic transmission, the speed change ratio control means obtains a speed change target value based on at least an operating point determined by a throttle opening and a vehicle speed. The ratio is controlled.
At this time, the inter-vehicle distance detecting means detects the inter-vehicle distance between the own vehicle and the preceding vehicle in the vehicle traveling direction, and the inter-vehicle distance length determining means determines the length of the inter-vehicle distance detected by the inter-vehicle distance detecting means. You. Then, the shift target value is determined such that the gear ratio is on the high side when the inter-vehicle distance is short, and the shift target value is determined such that the gear ratio is on the low side as the inter-vehicle distance is determined to be long. That is, the inter-vehicle distance from the preceding vehicle is detected by a laser or the like, and when the inter-vehicle distance is long, the speed ratio is set to a low side during acceleration (downshift state), so that the engine speed is used in a high rotation region. And sufficient acceleration can be ensured. On the other hand, when the inter-vehicle distance is short, by setting the gear ratio to the high side during acceleration (upshift state), it becomes possible to use the engine speed in a low rotation range, and the vehicle is not accelerated more than necessary. Therefore, the driver can easily perform accelerator control without excessively responding to the accelerator opening.

In the transmission control apparatus for an automatic transmission according to the present invention, a continuously variable transmission for continuously controlling the transmission ratio is used. Therefore, it is possible to select an optimal gear ratio without any gear shift shock.

In the shift control device for an automatic transmission according to the third aspect, in the shift control means, the shift speed is reduced when the inter-vehicle distance is short by the inter-vehicle distance length determining means, and as the inter-vehicle distance is determined to be long, Control for increasing the speed is performed. That is, for example, in a belt-type continuously variable transmission, a shift is performed by supplying hydraulic pressure to the pulleys during shifting. Therefore, it is possible to control the shift speed by this hydraulic pressure.
At this time, at the time of deceleration when the inter-vehicle distance is long, even if the driver indicates the intention of deceleration by releasing the accelerator, it is not necessary to rapidly reduce the speed. Upshifts, making it difficult to apply engine braking. Therefore, it is possible to smoothly decelerate without being too sensitive to the accelerator control. On the other hand, at the time of deceleration when the inter-vehicle distance is short, it is necessary to decelerate quickly when the driver indicates the intention to decelerate. At this time, the current gear ratio is easily maintained by reducing the gear speed. That is, the upshift is delayed, and the engine brake is easily applied. Therefore, it is possible to quickly respond to the accelerator control, and it is possible to reduce the speed with good responsiveness.

In the shift control device for an automatic transmission according to the present invention, when the shift control means performs the speed ratio control for increasing the shift speed, a correction line pressure is applied to the normal line pressure. That is, as described in the operation and effect of the third aspect, in the belt-type continuously variable transmission, the speed is changed by supplying the hydraulic pressure to the pulley. At this time, when it is determined that the inter-vehicle distance is long and a gear ratio control with a large gear speed is performed, a large oil pressure is required. Therefore, by applying the correction line pressure, it is possible to shift with good responsiveness.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a CVT cruise system to which the driving force control device according to the first embodiment is applied.

In FIG. 1, reference numeral 2 denotes a belt type CVT,
Is a laser radar mounted at a position in front of the vehicle and outputs radar information for measuring an inter-vehicle distance to a vehicle ahead.

An inter-vehicle distance measurement control unit 11 measures the inter-vehicle distance with a preceding vehicle based on radar information from the laser radar 10.

Reference numeral 14 denotes a belt type C so as to attain a target gear ratio.
A CVT control unit that controls the speed ratio of VT2 calculates a target speed ratio command value, and outputs a command to obtain the target speed ratio to the hydraulic control valve unit 15, which is a speed change actuator. The CVT control unit 14 constitutes a servo system that performs feedback control so that the actual gear ratio matches the target gear ratio.

9 is a throttle opening sensor, 20 is a torque converter, 21 is a lock-up clutch, 22 is a primary speed sensor, 23 is a secondary speed sensor,
24 is a line pressure solenoid, and 25 is an oil pump unit.

A torque converter 20 is connected to the output shaft of the engine as a rotation transmission mechanism.
A lock-up clutch 21 that directly connects T2 is provided.

The output side of the torque converter 20 is connected to a transmission input shaft 26. At the end of the input shaft 26, primary pulleys 27 and 28 of a belt type CVT 2 are provided.

The belt type CVT 2 has the primary pulleys 27 and 28, the secondary pulley 29.30, and a belt 31 for transmitting the rotational driving force of the primary pulleys 27 and 28 to the secondary pulleys 29 and 30. The movable pulley 28 of the secondary pulleys 28 can be moved in the axial direction of the input shaft 26 by the primary hydraulic pressure acting on the primary pulley cylinder chamber 32. The output shaft 34 can be moved in the axial direction by the secondary hydraulic pressure acting on the chamber 33. A drive gear (not shown) is fixed to the output shaft 34, and the drive gear drives a drive shaft reaching wheels through a pinion, a final gear, and a differential device provided on the idler shaft.

By moving the movable primary pulley 28 and the secondary pulley 30 in the axial direction to change the contact position radius with the belt 31, the primary pulley 2
The rotation ratio between the pulleys 7 and 28 and the secondary pulleys 29 and 30, ie, the gear ratio, can be changed. Such primary pulleys 27 and 28 and secondary pulleys 29,
The control for changing the groove width of the V-shaped pulley groove 30 is CV
A primary hydraulic pressure and a secondary hydraulic pressure are generated by the hydraulic control valve unit 15 according to a command from the T control unit 14, and these hydraulic pressures are supplied to the primary pulley cylinder chamber 32 and the secondary pulley cylinder chamber 33, respectively.

The CVT control unit 14 includes a throttle opening signal from the throttle opening sensor 9, a switch signal from a kick down switch 35, a vehicle speed signal from a vehicle speed sensor 36, and a transmission oil temperature signal from an oil temperature sensor 37. The primary rotation speed signal from the primary rotation speed sensor 22, the secondary rotation speed signal from the secondary rotation speed sensor 23, and other signals are input. C
The VT control unit 14 performs arithmetic processing based on these input signals, outputs a line pressure control signal to the line pressure solenoid 7, outputs a gear ratio control signal to the hydraulic control valve unit 6, and outputs a gear ratio control signal to the oil pump unit 25. Outputs an oil pump unit control signal.

FIG. 2 is a flowchart showing control in the CVT control unit according to the first embodiment.

In step 101, the length of the inter-vehicle distance is determined (see FIG. 3). If there is no normal area and no preceding vehicle, normal control is performed. If the inter-vehicle distance is short, the process proceeds to step 106, and if the inter-vehicle distance is long, Goes to step 102.

In step 102, the target gear ratio is calculated from the gear map for the long distance between vehicles (see FIG. 4).

In step 103, the shift speed is calculated from the shift speed map for the long distance between vehicles (see FIG. 6).

In step 104, the correction line pressure is calculated from the line pressure correction map (see FIG. 7), and the correction line pressure is added to the normal line pressure.

In step 105, the target speed ratio and the actual speed ratio are compared, and if the actual speed ratio has reached the target speed ratio,
This control is terminated.
Continue to shift gears.

In step 106, a target gear ratio is calculated from the gear shift map for the distance between short vehicles (see FIG. 5).

In step 107, the shift speed is calculated from the shift speed map for the distance between short vehicles (see FIG. 6).

In step 108, the target speed ratio and the actual speed ratio are compared, and if the actual speed ratio has reached the target speed ratio,
This control is ended, and if the speed has not been reached, the shift is continued using the shift speed map for the short inter-vehicle distance.

That is, the length of the inter-vehicle distance is determined from the inter-vehicle distance detected by the laser radar 10, and the length of the inter-vehicle distance detected from the vehicle speed map shown in FIG. 3 is determined.
At this time, if it is in the normal area in the figure, normal control is performed.

(At long inter-vehicle distance) When it is determined that the inter-vehicle distance is long, the target speed ratio is calculated using the inter-vehicle distance shift map. This map is set so that the target primary rotation speed (engine speed) becomes higher than the speed change map used for normal control, and is set so as to be able to sufficiently accelerate.

Next, a shift speed is calculated from a deviation between the target speed ratio and the actual speed ratio shown in FIG. 6 using a shift speed map for a long distance between vehicles. At this time, the shift speed for the long distance between vehicles is set to be faster than that in the normal control. As a result, during deceleration when the inter-vehicle distance is long, even if the driver indicates the intention to decelerate by releasing the accelerator, it is not necessary to rapidly decelerate, so the upshift will be performed early, and the engine will be shifted early. It is hard to apply the brake. Therefore,
You can decelerate smoothly without being too sensitive to accelerator control.

Next, the correction line pressure shown in FIG. 7 is calculated from the gear ratio and added to the normal line pressure. This allows
The pulley ratio can be changed with good responsiveness even if the speed change speed is set to be high at the distance between long vehicles.

FIG. 8 is a time chart at the time of acceleration for a long distance between vehicles. As shown in the figure, when the driver opens the throttle opening in the state where it is determined that the long distance between vehicles has been set, the target gear ratio is set to a higher target gear ratio than that in the normal control, and the correction line pressure becomes the normal line speed. Is added to the pressure. At this time, since the shift speed is set high, the actual speed ratio can also approach the target speed ratio with good responsiveness. In addition, it is possible to obtain a larger acceleration than in the normal control.

When the inter-vehicle distance is determined to be short, the target gear ratio is calculated using the short-vehicle distance shift map. This map is set so that the target primary rotational speed (engine speed) becomes lower than the speed change map used for normal control, and is set so as not to accelerate excessively.

Next, the shift speed is calculated from the difference between the target speed ratio and the actual speed ratio shown in FIG. 6 using a shift speed map for a short vehicle distance. At this time, the shift speed for the short inter-vehicle distance is set to be lower than that in the normal control. As a result, even when the driver steps on the accelerator, it is not necessary to accelerate sharply during acceleration when the inter-vehicle distance is short, so it is possible to accelerate gently and become sensitive to accelerator control. And can smoothly decelerate.

FIG. 9 is a time chart at the time of deceleration for the distance between short vehicles. As shown in the figure, when the driver closes the throttle opening in the state where it is determined that the distance is short,
The target gear ratio is set to a lower target gear ratio than during normal control. At this time, since the gear speed is set low, the actual gear ratio can approach the target gear ratio more smoothly than during normal control. That is, at the time of a single-vehicle distance, when the driver indicates the intention to decelerate, it is necessary to decelerate quickly. At this time, the current gear ratio is easily maintained by reducing the gear speed. That is, the upshift is delayed, and the engine brake is easily applied. Therefore, it is possible to quickly respond to the accelerator control, and it is possible to reduce the speed with good responsiveness.

As described above, in the transmission control apparatus for the automatic transmission according to the first embodiment, by performing the above-described control, when the preceding vehicle is present during traveling, the inter-vehicle distance to the preceding vehicle is determined. , The burden of the driver on accelerator control due to excessive acceleration / deceleration can be reduced. Also, when the inter-vehicle distance is long, it is possible to obtain greater acceleration than during normal control, and to prevent the engine brake from being applied more than necessary during deceleration, thereby reducing the burden of accelerator control. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main unit of a vehicle including a belt-type continuously variable transmission according to an embodiment.

FIG. 2 is a flowchart illustrating control of a CVT control unit according to the first embodiment.

FIG. 3 is a map for determining a length of an inter-vehicle distance according to the first embodiment.

FIG. 4 is a diagram illustrating a relationship between a vehicle speed and a target primary rotation speed at a short inter-vehicle distance in the first embodiment.

FIG. 5 is a diagram illustrating a relationship between a vehicle speed and a target primary rotation speed at the time of a long inter-vehicle distance according to the first embodiment.

FIG. 6 is a diagram illustrating a relationship between a shift speed and a deviation between a target speed ratio and an actual speed ratio in the first embodiment.

FIG. 7 is a diagram illustrating a relationship between a gear ratio and a correction line pressure according to the first embodiment.

FIG. 8 is a time chart at the time of acceleration at the distance between long vehicles according to the first embodiment.

FIG. 9 is a time chart at the time of deceleration at the time of a short inter-vehicle distance in the first embodiment.

[Explanation of symbols]

 2 Belt-type continuously variable transmission 6 Hydraulic control valve unit 7 Line pressure solenoid 9 Throttle opening sensor 10 Laser radar 14 Control unit 15 Hydraulic control valve unit 20 Torque converter 21 Lock-up clutch 22 Primary speed sensor 23 Secondary speed sensor 25 Oil pump unit 26 Input shaft 26 Transmission input shaft 27, 28 Primary pulley 29, 30 Secondary pulley 31 Belt 32 Primary pulley cylinder chamber 33 Secondary pulley cylinder chamber 34 Output shaft 34 The output shaft 35 Kick-down switch 36 Vehicle speed sensor 37 Oil temperature Sensor

Claims (4)

[Claims] 1. A shift control device for an automatic transmission, comprising a shift ratio control means for determining a shift target value based on at least an operating point determined by a throttle opening and a vehicle speed, and controlling a shift ratio of the automatic transmission. An inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle in a vehicle traveling direction, and inter-vehicle distance determining means for determining the inter-vehicle distance detected by the inter-vehicle distance detecting means; The shift target value is determined so that the gear ratio becomes high when the inter-vehicle distance determined by the inter-vehicle distance length determining means is short, and as the inter-vehicle distance is determined to be long, the gear ratio becomes low. A shift control device for an automatic transmission, wherein the shift target value is obtained. 2. The shift control device for an automatic transmission according to claim 1, wherein the automatic transmission is a continuously variable transmission that controls a speed ratio in a stepless manner. Control device. 3. A shift control device for an automatic transmission, comprising: a shift ratio control unit for determining a shift target value based on at least an operating point determined by a throttle opening and a vehicle speed to control a shift ratio of the automatic transmission. When controlling the gear ratio, the control means performs control such that if the inter-vehicle distance determined by the inter-vehicle distance length determining means is short, the shift speed is reduced, and if the inter-vehicle distance is determined to be long, the shift speed is increased. A shift control device for an automatic transmission, comprising: 4. The shift control device for an automatic transmission according to claim 3, wherein the shift control means applies a correction line pressure to a normal line pressure when performing a speed ratio control for increasing a shift speed. A shift control device for an automatic transmission, comprising: