JP2002002327A - Vehicle travel control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve smooth driving performance of a vehicle having an electronically controlled throttle device and an automatic transmission, by preventing too sensitive shift control while increasing the responsiveness of engine output control when the vehicle is controlled to travel at constant speed. SOLUTION: A throttle motor control part 20 or a transmission controller 15 controls the throttle opening of an engine or the gear ratio of the transmission in accordance with a throttle opening command value transmitted from a throttle opening computing part 16 or a driving force command value transmitted from a constant speed control computing part 17 when the vehicle is controlled to travel at constant speed, with both values based on the operating value of an accelerator pedal. While the vehicle is controlled to travel at constant speed, a command value equivalent to the throttle opening, obtained through inverse conversion from the driving force command value and from vehicle speed, is outputted to the transmission controller by searching a map 22. Thus, a gear ratio control system is hierarchized to avoid formation of a control loop causing hunting, so as to appropriately control the gear ratio while increasing the accuracy of controlling the throttle opening when the vehicle is controlled to travel at constant speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel control device for a vehicle, and more particularly to an improvement of a travel control device having a function of automatically controlling a vehicle speed.

[0002]

2. Description of the Related Art As a typical vehicle travel control device, there is a so-called constant speed travel device or cruise control device for automatically controlling travel at a constant vehicle speed designated by a driver. FIG. 4 shows an example. When the set switch 1 is closed by a driver's operation, the vehicle speed detected by the vehicle speed sensor 2 at this time is stored in the control device 3 as a target value, and thereafter, the engine throttle valve is adjusted so that the target value matches the actual vehicle speed. 4
Is feedback-controlled. A vacuum motor 5 is connected to the throttle valve 4 as an actuator for automatically controlling the opening. The opening of the throttle valve 4 is normally adjusted in accordance with the operation of an accelerator pedal (not shown) connected by a wire, but the opening is adjusted by the vacuum motor 5 at the time of constant speed running control. In this case, the throttle opening of the engine is changed by adjusting the operation negative pressure to the vacuum motor 5 by the control device 3 through the control valve 6. Also, in contrast to the conventional configuration based on a mechanism for transmitting the depression operation of the accelerator pedal to the throttle valve by a wire as described above, a so-called electronically controlled throttle device in which the throttle opening is controlled only by an actuator in recent vehicles. Is being applied. In the electronic control throttle device, the operation of the accelerator pedal is converted into an electric signal by a sensor, and the controller controls the opening of the throttle valve by driving an actuator such as a step motor based on the signal.

[0003] By the way, vehicles equipped with an automatic transmission are:
Generally, the gear ratio is configured to change depending on the accelerator pedal operation amount and the vehicle speed.However, when a constant speed traveling device is used in combination, the accelerator pedal operation amount becomes equivalent to idle during constant speed traveling. Therefore, the signal from the accelerator pedal cannot be applied to the gear ratio control. Therefore, the gear ratio is controlled by an opening control signal to the throttle actuator as a signal representative of the required driving force. In such a case, a lean burn engine that performs lean air-fuel ratio operation by stratified combustion or the like is used. Then
In order to secure the air amount, control is performed so that the throttle opening is larger than the accelerator operation amount.
There is a problem that the gear ratio is not always appropriate for the required driving force.

In a configuration in which a gear ratio is controlled using a throttle opening control signal, the throttle opening changes more sensitively as control performance such as convergence to disturbance during constant speed running control is enhanced. Therefore, there occurs a problem that the automatic transmission shifts excessively and the drivability deteriorates. That is, in the conventional constant-speed traveling device, the throttle opening is directly calculated as a command value by PID control or the like in the vehicle speed servo control, so that both the change in the running resistance during the constant-speed running and the change in the driving force due to the shift are regarded as the same disturbance. Absorbed by servo control. For this reason, for example, if the control gain is set in accordance with a large change in disturbance such as a gear step, the throttle opening will be changed unnecessarily and stability will be impaired, and it will be adjusted to disturbance that changes slowly like running resistance. Therefore, the following immediately after the shift is poor and a large vehicle speed deviation occurs.
(Publications include JP-A-11-321387 and JP-A-200
See 0-18378. The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a traveling control device having excellent shift controllability of an automatic transmission.

[0005]

According to a first aspect of the present invention, there is provided first driving force control means for outputting a throttle opening command value in response to a driver's operation of an accelerator pedal, and a first driving force control means for achieving a predetermined target vehicle speed. A second driving force control means for outputting a driving force command value, a throttle opening control means for controlling a throttle valve opening of the engine based on a command value from any one of the driving force control means, and an automatic transmission. A gear ratio control means for controlling a gear ratio, and a command value equivalent to a throttle opening based on a driving force command value from the second driving force control means and a vehicle speed signal, and outputting the command value to the gear ratio control means. A traveling control device for a vehicle comprising a degree command value output means.

According to a second aspect of the present invention, the opening command value output means includes a driving force map for giving a driving force command value based on the throttle opening and the vehicle speed. To calculate a command value equivalent to the throttle opening.

According to a third aspect of the present invention, the first driving force control means includes an engine torque map for giving an engine torque command value from a throttle opening and an engine speed. An engine torque command value obtained by dividing the driving force command value from the driving force control means by the actual gear ratio and an engine speed signal are inversely converted to calculate a throttle opening command value.

[0008] In a fourth aspect based on the first aspect,
The driving force control means is configured to calculate a throttle opening command value based on a signal from an accelerator pedal sensor that detects an accelerator pedal operation amount.

According to a fifth aspect, in the first aspect,
The throttle opening control means is configured to control a throttle valve opening by driving a throttle motor based on a throttle opening command value.

In a sixth aspect based on the first aspect,
The second driving force control means is configured to calculate a driving force command value at which a target vehicle speed is obtained by feeding back the actual vehicle speed.

[0011] In a seventh aspect based on the first aspect,
The second driving force control means is configured as a constant speed traveling control device that outputs a driving force command value so that the actual vehicle speed matches a fixedly set target vehicle speed.

[0012] In an eighth aspect based on the first aspect,
The second driving force control means is configured as a vehicle speed automatic control device that outputs a driving force command value so that the actual vehicle speed matches a variably set target vehicle speed.

[0013]

According to the first aspect of the present invention, the throttle opening control means and the speed ratio control means each provide a throttle opening command value from the first driving force control means based on the accelerator pedal operation amount, or travel control. In this state, the throttle opening of the engine or the gear ratio of the transmission is controlled by the driving force command value from the second driving force control means. However, the second
In a traveling control state in which the throttle opening or the gear ratio is controlled by the driving force command value from the driving force control means, the command value from the opening command value output means is given to the gear ratio control means. That is, at this time, the opening command value output means calculates a command value corresponding to the throttle opening from the driving force command value from the second driving force control means and the vehicle speed signal, and outputs this to the gear ratio control means. . When the throttle opening and the vehicle speed are determined, the shift state at the operating point (the gear ratio in the case of the continuously variable transmission, and the gear position in the case of the planetary gear type automatic transmission) is determined from the known shift map of the automatic transmission. The engine speed is obtained from the vehicle speed, the engine torque at the operating point is obtained from the throttle opening and the engine speed based on the known engine torque characteristics, and the driving force is obtained by multiplying the engine torque by the gear ratio. . Accordingly, by calculating the above relationship while changing the throttle opening and the vehicle speed and forming a map in advance, it is possible to obtain the throttle opening equivalent value in an inverse manner from the driving force command value and the vehicle speed. it can.

In this manner, the value corresponding to the accelerator opening is inversely converted from the relationship between the driving force and the vehicle speed and given to the speed ratio control means. Even if the throttle opening control is performed to respond to a relatively large disturbance while optimizing the gear ratio control, the accelerator opening at that time can be absorbed. It is possible to avoid such inconvenience that the degree affects the gear ratio. In this case, the transmission ratio control means performs processing by distinguishing the throttle opening command value output from the first driving force control means by the operation of the accelerator pedal and the command value corresponding to the throttle opening during the traveling control. No need,
Therefore, complication of the circuit configuration can be avoided. On the other hand, during a normal operation in which the throttle opening is controlled by the accelerator pedal, the throttle opening command value from the first driving force control means is given to the speed ratio control means. Even if the throttle opening is greatly corrected with respect to the accelerator operation amount, this correction does not affect the gear ratio control, that is, the gear ratio is adjusted to an appropriate gear ratio for the driving force required by the driver. Can be controlled.

[0015] As shown in the second invention, the opening command value output means in the first invention is provided with a driving force map for giving a driving force command value from the throttle opening and the vehicle speed.
The driving force map may be inversely converted between the driving force command value and the vehicle speed to calculate a command value corresponding to the throttle opening. Further, as described in the third aspect, the first driving force control means includes an engine torque map for giving an engine torque command value from the throttle opening and the engine speed. A throttle opening command value calculated by inversely converting an engine torque command value obtained by dividing a driving force command value from a second driving force control means by an actual gear ratio and an engine speed signal; It can be. With this configuration, a relatively large disturbance such as that caused by a shift operation of the transmission can be absorbed with good response in the calculation portion of the throttle opening command value.

If only the configuration of the third aspect of the invention is applied to a travel control device which outputs a throttle opening signal to a transmission control system to control the transmission ratio of the automatic transmission, the actual transmission ratio Change → change in throttle opening command value → change in gear ratio command value → change in actual gear ratio. On the other hand, when the transmission is upshifted, the throttle opening increases, which causes the transmission to downshift. Therefore, there is a possibility that control hunting may occur. This control hunting has the disadvantages of repeated upshifting and downshifting when an automatic transmission of a planetary gear type is applied, and periodic fluctuation of the gear ratio when a CVT (continuously variable transmission) is applied. Appears. On the other hand, in the present invention, since the command value to the transmission control means is hierarchically given by the opening command value output means as described above, the control loop as described above is not formed. That is, in the present invention, the shift control is performed by the command value from the opening command value output means, and the opening command value to the throttle valve is calculated based on the shift result, so that the control accuracy of the throttle opening is improved. Also, the phenomenon that the gear ratio causes hunting does not occur, so that good controllability can be ensured for both the traveling control and the gear ratio control.

In the first invention, the first driving force control means includes a throttle opening command value based on a signal from an accelerator pedal sensor for detecting an accelerator pedal operation amount, as described in the fourth invention. Can be calculated. The throttle opening control means may be configured to control the throttle valve opening by driving the throttle motor based on the throttle opening command value, as described in the fifth invention. Further, similarly as the second driving force control means, as shown in the sixth invention, it is possible to adopt a configuration in which the actual vehicle speed is fed back to calculate a driving force command value for obtaining the target vehicle speed.

In the first invention, the second driving force control means, as described in the seventh invention, controls the driving force command so that the actual vehicle speed matches the fixedly set target vehicle speed. It can be configured as a constant speed cruise control device that outputs a value,
Alternatively, as shown in the eighth invention, for example, according to a vehicle control signal supplied by a mobile communication system,
An automatic vehicle speed control device that outputs a driving force command value so that the actual vehicle speed coincides with a variably set target vehicle speed can also be configured.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a set switch for constant speed control, 2 is a vehicle speed sensor, and 4 is a throttle valve. Reference numeral 11 denotes a controller having functions as a driving force control unit and a throttle opening degree control unit according to the present invention, and reference numeral 15 denotes a transmission controller also having a function as a speed ratio control unit. Each of the controllers 11 and 15 is configured as a microcomputer that performs input / output processing and arithmetic processing of various signals necessary for the respective controls. Reference numeral 12 denotes an accelerator pedal sensor for detecting an operation amount of an accelerator pedal 13, reference numeral 14 denotes a throttle motor which drives the throttle valve 4 in response to a command from the controller 11, and reference numeral 23 denotes a throttle ratio which is not received in response to a command from the transmission controller 15. Continuously variable automatic transmission (CV
T) and 24 are throttle sensors for detecting the opening of the throttle valve 4.

The blocks indicated as symbols 16 to 22 in the controller 11 indicate processing functions formed on a central processing unit (CPU), 16 is a throttle opening command value calculating section, and 17 is a constant speed. A control operation unit, 18 is a throttle opening correction operation unit, 19a and 19b are command value selection units,
20 is a throttle motor control unit, 21 is a first map for giving a throttle opening command value to the throttle motor 14,
Reference numeral 22 denotes a second map for giving a command value equivalent to the throttle opening to the transmission controller 15. The first map 21 is an engine torque map that gives an engine torque command value based on the throttle opening and the engine speed.
Is configured as a driving force map for giving a driving force command value from the throttle opening and the vehicle speed.

The throttle opening command value calculating section 16 calculates a throttle opening command value based on the accelerator pedal operation amount signal input from the accelerator pedal sensor 12, and outputs this to the command value selecting sections 19a and 19b. I do. The first command value selection section 19a outputs the throttle opening command value to the throttle motor control section 20 via the throttle opening correction calculation section 18 except during constant speed control described later. The second command value selecting section 19b outputs a throttle opening command value to the transmission controller 15 except during the constant speed control. Throttle motor control unit 20
Output feedback command value to the throttle motor 14 and perform feedback control while monitoring the signal from the throttle sensor 24 so that the throttle valve 4 becomes the command opening, while the transmission controller 15 Automatic transmission 23 so that a predetermined driving force is obtained based on the command value.
Control the transmission gear ratio. Further, the throttle opening correction calculation unit 18 performs a throttle opening increase correction calculation and the like when performing the lean air-fuel ratio operation.

On the other hand, the constant speed control calculation unit 17 calculates a driving force command value for constant speed control based on a signal indicating the state of the set switch 1 and a vehicle speed signal from the vehicle speed sensor 2. Is output to the command value selection units 19a and 19b. However, the driving force command value to the throttle motor control unit 20 is divided by the actual speed ratio signal obtained from the automatic transmission 23, and the engine torque value resulting from this division is compared with the engine speed signal from an engine speed sensor (not shown). Thus, the throttle opening command value obtained by inversely converting the first map 21 is output to the command value selecting unit 19a. Also,
The driving force command value to the transmission controller 15 is provided to the second map 22 together with the vehicle speed signal from the vehicle speed sensor 2,
The command value selection unit 19b outputs a command value equivalent to the throttle opening obtained by inversely converting the second map 22.

As the processing in the constant speed control calculation section 17, the vehicle speed when the set switch 1 is operated (closed) is stored as a target value, and the actual vehicle speed matches the target vehicle speed while monitoring the vehicle speed signal. Such a driving force is calculated and output as a driving force command value. At this time, the command value selection unit 19a,
In 19b, when a command value from the maps 21 and 22 is input based on the driving force command value from the constant speed control calculation unit 17, the throttle value is given priority over the command value from the throttle opening command value calculation unit 16. Motor control unit 20 (throttle opening correction operation unit 18) and transmission controller 1
By outputting the signal to 5, a constant speed traveling control independent of the accelerator pedal operation is performed. The constant speed traveling control is terminated by, for example, a driver's release operation or braking operation, and thereafter, unless the set operation of the constant speed traveling is performed again, the throttle opening degree and the gear ratio based on the accelerator pedal operation described above are changed. Control is performed.

As described above, the throttle motor control unit 20 or the transmission controller 15 controls the throttle opening command value calculation unit 16 based on the accelerator pedal operation amount.
The throttle opening of the engine or the gear ratio of the transmission is controlled by the throttle opening command value from the engine or the command value based on the driving force command value from the constant speed control calculation unit 17 in the constant speed running control state. That is, in a constant-speed running control state in which the throttle opening or the gear ratio is controlled by a command value from the constant-speed control calculating unit 17, the transmission controller 15
Is a command value corresponding to the throttle opening provided by the second map 22.

As described above, since the required driving force can be obtained from the throttle opening and the vehicle speed, by mapping these relationships for a large number of combinations of the throttle opening and the vehicle speed, the driving force can be obtained. The value can be obtained by inversely converting the throttle opening equivalent value from the command value and the vehicle speed. FIG. 2 or FIG. 3 is an example of the configuration of the second map 22 formed as described above. FIG. 2 shows an example of the case of an automatic continuously variable transmission. In this case, since the gear ratio changes continuously, the curve giving the throttle opening equivalent value smoothly changes from the relationship between the vehicle speed and the driving force. Become. FIG.
Is an example of an automatic transmission in which a stepped transmission mechanism using planetary gears and a torque converter are combined, and a step difference due to the transmission mechanism originally occurs as shown by a dashed line, but if it is left as it is, the accelerator opening degree is reduced. Since it is inconvenient for the inverse conversion, the smoothing is performed as shown by the solid line so that an appropriate value corresponding to the throttle opening can be obtained.

The throttle opening control under the above-described constant-speed running control state is performed by dividing the driving force command value calculated by the constant-speed control calculating section 17 by the actual gear ratio, the engine torque value and the engine speed. From the first map 21 and outputs the throttle opening command value. Therefore, depending on the setting of the map 21, precise driving force control with high responsiveness to a large disturbance can be performed. On the other hand, if the accuracy of the throttle opening control is increased as described above, hunting is likely to occur in the transmission ratio control system, but in the present invention, the command value corresponding to the throttle opening to the transmission controller 15 is controlled by the constant speed control. Since the second map 22 has a hierarchical structure based on the driving force command value and the vehicle speed from the arithmetic unit 17, the setting of this map 22 optimizes the disturbance specific to the gear ratio control system against disturbance. And hunting can be avoided to achieve smooth running. Further, the transmission controller 15 does not need to process the throttle opening command value by the operation of the accelerator pedal and the command value corresponding to the throttle opening at the time of the traveling control so that there is no need to change the existing circuit configuration. .

On the other hand, during normal operation in which the throttle opening is controlled based on the operation of the accelerator pedal 13,
Since the command value from the throttle opening command value calculating section 16 is directly given to the transmission controller 15, even in an operating condition in which the throttle opening is greatly corrected by the throttle opening correction calculating section 18, This correction does not affect the gear ratio control, that is, the gear ratio can be controlled to be appropriate for the driving force required by the driver.

In the transmission controller 16, the speed ratio control is performed with reference to a map for giving the speed ratio in accordance with the throttle opening and the vehicle speed. Instead of using the throttle opening as described above, a constant speed control is performed. By forming a map so as to give a gear ratio from the driving force command value calculated by the control calculation unit 17 and the vehicle speed, it is possible to avoid formation of a control loop that causes hunting. However, in such a map configuration, it is practically difficult to obtain a shift characteristic without a sense of incongruity similar to a shift map using the throttle opening at the time of shifting by the accelerator pedal operation of the driver. Particularly, in a planetary gear type automatic transmission in which the driving force does not continuously change, it is extremely difficult to construct a shift map based on the driving force.

In the above-described embodiment, the throttle opening command value is calculated using only the accelerator pedal operation amount. However, the present invention is not limited to this. In addition, the throttle opening command value is calculated using a vehicle speed signal or an engine speed signal. It is also possible to adopt a configuration in which the throttle opening command value is determined by PID control or the like so as to obtain the tire driving force in the period.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration example of a second map in the embodiment.

FIG. 3 is an explanatory diagram showing another configuration example of the second map in the embodiment.

FIG. 4 is a schematic configuration diagram of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 set switch 2 vehicle speed sensor 4 throttle valve 11 controller 12 accelerator pedal sensor 13 accelerator pedal 14 throttle motor 15 transmission controller 16 throttle opening command value calculation unit 17 constant speed control calculation unit 18 throttle opening correction calculation unit 19a, 19b command Value selector 20 Throttle motor controller 21 First map 22 Second map 23 Continuously variable automatic transmission (CVT) 24 Throttle sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) F02D 29/02 301 F02D 29/02 301C 41/04 301 41/04 301G 41/14 320 41/14 320D F16H 61/02 F16H 61/02 // F16H 59:18 59:18 59:24 59:24 59:44 59:44 59:70 59:70 F term (reference) 3D041 AA53 AA66 AA67 AB01 AC01 AC15 AC18 AC19 AD02 AD04 AD10 AD51 AE04 AE31 AE45 AF01 3D044 AA01 AA41 AB01 AC15 AC22 AC26 AD04 AD17 AE04 AE14 AE19 AE21 3G093 AA01 AA05 BA02 BA23 CB10 DB05 DB11 EA09 EB03 EC02 FA04 FA10 3G301 JA04 KB02 PA03 MA01 PN02 MA03 PN03 MA03 PA54 RB11 SA01 SA31 SB02 UA08 VB01W VC01Z VC03W VD02W VD17Z

Claims (8)

[Claims] 1. A first driving force control means for outputting a throttle opening command value in response to an operation of an accelerator pedal by a driver, and a second driving force command value for outputting a driving force command value for achieving a predetermined target vehicle speed. A driving force control unit, a throttle opening control unit that controls a throttle valve opening of an engine based on a command value from any one of the driving force control units, and a gear ratio control unit that controls a gear ratio of an automatic transmission. Opening command value output means for calculating a command value equivalent to a throttle opening from the driving force command value from the second driving force control means and a vehicle speed signal and outputting the command value to the speed ratio control means. Vehicle travel control device. 2. An opening command value output means includes a driving force map for giving a driving force command value based on a throttle opening and a vehicle speed. The driving force map is inversely converted between the driving force command value and the vehicle speed. The vehicle travel control device according to claim 1, further comprising a configuration for calculating a command value corresponding to the throttle opening by using a command. 3. The first driving force control means includes an engine torque map for giving an engine torque command value based on a throttle opening and an engine speed. 2. The vehicle according to claim 1, wherein the throttle opening command value is calculated by performing an inverse conversion between an engine torque command value obtained by dividing a driving force command value from the engine by an actual gear ratio and an engine speed signal. Travel control device. 4. The vehicle according to claim 1, wherein said first driving force control means calculates a throttle opening command value based on a signal from an accelerator pedal sensor for detecting an accelerator pedal operation amount. Travel control device. 5. The vehicle running control device according to claim 1, wherein the throttle opening control means drives the throttle motor to control the throttle valve opening based on the throttle opening command value. 6. The vehicle travel control device according to claim 1, wherein said second driving force control means is configured to calculate a driving force command value by which an actual vehicle speed is fed back to obtain a target vehicle speed. 7. The constant speed traveling control device according to claim 1, wherein said second driving force control means outputs a driving force command value so that an actual vehicle speed coincides with a fixedly set target vehicle speed.
A travel control device for a vehicle according to claim 1. 8. The vehicle speed automatic control device according to claim 1, wherein said second driving force control means outputs a driving force command value such that an actual vehicle speed coincides with a variably set target vehicle speed.
A travel control device for a vehicle according to claim 1.