JP2009078809A - Running control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate excess/shortage of the marginal driving force and thereby reduce the amount of fuel consumption. <P>SOLUTION: A required driving force calculation part 10 calculates the required driving force on the basis of the amount of accelerator being stamped by the driver and the speed of the vehicle concerned. A preceding vehicle recognition part 20 acknowledges the vehicle running ahead and calculates the distance from the preceding vehicle, relative speed, etc. A running situation judging part 30 judges the running situation of the vehicle concerned on the basis of the preceding vehicle information including the inter-vehicle distance and relative speed recognized by the preceding vehicle recognition part 20 and the heading course altering information including the amount of steering wheel being turned, the operating signal for a direction indicator, etc. A required marginal driving force calculation part 40 calculates the required marginal driving force to be secured at each time on the basis of the running situation of the vehicle concerned judged by the running situation judging part 30, in addition to the amount of accelerator being operated and the vehicle speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle running state control device.

  Conventionally, the marginal driving force calculated in preparation for future acceleration requests is added to the target driving force calculated based on the driver's output request and vehicle speed, etc., and the driving state of the vehicle is controlled with the best fuel consumption using the result. A technique is known (see, for example, Patent Document 1).

  Here, the margin driving force is considered so that it can respond in a short time to the driving force increase request generated in the near future from now, and the shift schedule and lean operation conditions are set in consideration of this margin driving force. Is done. For example, in a vehicle equipped with an automatic transmission, the marginal driving force is set in advance in consideration of the running performance and fuel consumption performance of the vehicle, or the gear stage and the engine operation mode are set in consideration of the marginal driving force. In this case, in a normal ordinary vehicle, if the marginal driving force is set large, for example, the vehicle is operated with a low-speed gear, and the engine speed increases. That is, there is a contradictory relationship that fuel efficiency deteriorates when trying to increase acceleration performance.

Further, since the required amount of the marginal driving force changes depending on the road condition, it is possible that the marginal driving force is excessively secured and the fuel efficiency is deteriorated. In Patent Document 1, an attempt is made to set a margin driving force according to a road gradient by calculating a margin driving force based on road gradient information obtained by a navigation system or the like, but the host vehicle travels alone. However, if there is another vehicle, a sufficient effect cannot be expected. In other words, the necessary margin driving force is considered to change depending on not only the road gradient but also the relative relationship between the host vehicle and the other vehicle. Therefore, the above-mentioned Patent Document 1 has a problem that the fuel efficiency improvement effect is insufficient.
Japanese Patent Application Laid-Open No. 2002-254962

  The main object of the present invention is to provide a vehicle control system capable of appropriately performing fail-safe treatment as necessary.

  In the vehicle travel state control device according to claim 1, the travel state of the host vehicle including a relative relationship with other vehicles traveling around is determined, and the marginal driving force is increased based on the determined travel state of the host vehicle. Or reduced. In other words, when there is another vehicle around the host vehicle, it may be necessary to increase the driving force beyond the current level or not depending on the relative relationship of the other vehicle. In this case, by determining the marginal driving force in consideration of the traveling state of the host vehicle, it is possible to eliminate the excess or deficiency of the marginal driving force, thereby reducing the fuel consumption.

  Further, in the first aspect of the present invention, when it is determined that the other vehicle traveling around the host vehicle is close to the host vehicle, the marginal driving force is increased. For example, when the inter-vehicle distance with the side vehicle or the rear vehicle is reduced, there is a possibility of overtaking to prevent a subsequent collision. In this case, by increasing the marginal driving force, it is possible to perform appropriate risk avoidance traveling while reflecting the driver's acceleration intention.

  In the invention of claim 2, when it is determined that the vehicle is following the vehicle without overtaking another vehicle existing in a predetermined area in front of the host vehicle, the margin driving force is reduced. In other words, the possibility of future acceleration is low when traveling following other vehicles. In this case, the fuel efficiency can be reduced by reducing the marginal driving force.

  Here, when it is determined that the host vehicle is traveling at substantially the same speed with respect to the other vehicle in the predetermined area ahead and the vehicle is following the other vehicle when the course of the host vehicle is not changed. Good (claim 3). The presence / absence of a change in the course of the host vehicle may be determined based on a handle operation amount (steering angle information), operation information on a direction indicator, or the like.

  In the invention of claim 4, when it is determined that the vehicle is overtaking another vehicle existing in a predetermined area in front of the host vehicle, the margin driving force is increased. That is, when overtaking another vehicle, a quick acceleration response is required. In this case, it is possible to appropriately reflect the driver's acceleration intention by increasing the marginal driving force.

  Here, when the host vehicle is approaching another vehicle in a predetermined area in front and the course of the host vehicle is changed, it is preferably determined that the vehicle is overtaking the other vehicle.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. The present embodiment is applied to an automobile control system, and a method for suitably controlling an engine, an automatic transmission, and the like by an electronic control unit (hereinafter referred to as ECU) in the control system will be described in detail below. Describe. Although not shown because it is a well-known configuration, the vehicle includes an engine and an automatic transmission with a torque converter connected to the crankshaft (output shaft) of the engine, and the output of the engine is transmitted via the crankshaft. The vehicle travels by being transmitted to the automatic transmission, and further by transmitting the rotation of the output shaft of the automatic transmission to the wheels via the differential gear and the axle. Further, the engine is provided with a throttle actuator for adjusting the opening degree of the throttle valve, and the throttle opening degree is electrically controlled in accordance with the accelerator operation amount of the driver and the like.

  FIG. 1 is a functional block diagram of an ECU relating to vehicle driving force control. First, an overview of the overall control will be described.

  In FIG. 1, the required driving force calculation unit 10 calculates the required driving force based on the accelerator operation amount by the driver and the vehicle speed of the host vehicle. Further, the forward vehicle recognition unit 20 is configured by a laser radar sensor or the like, recognizes another vehicle that travels in front of the host vehicle (hereinafter referred to as a forward vehicle), and determines an inter-vehicle distance, a relative speed, and the like with the forward vehicle. calculate. More specifically, the laser radar sensor includes a light emitting unit that irradiates laser light toward a predetermined area in front of the vehicle, and a light receiving unit that receives a reflected wave of the laser light irradiated to the front of the vehicle. It is configured to scan a predetermined area in front of the vehicle at a predetermined cycle. Then, a signal corresponding to the time until the reflected wave is received by the light receiving unit after the laser beam is emitted from the light emitting unit, and a signal corresponding to the incident angle of the reflected wave are output from the laser radar sensor. Based on the signal, an inter-vehicle distance to a front vehicle existing in a predetermined area in front of the host vehicle is detected, and a relative speed with respect to the front vehicle (unit of inter-vehicle distance is determined by differentiating the detected inter-vehicle distance. Change amount per hour) is detected.

  The traveling state determination unit 30 is based on the forward vehicle information such as the inter-vehicle distance and the relative speed recognized by the forward vehicle recognition unit 20 and the traveling state of the host vehicle based on the route change information such as the steering wheel operation amount and the direction indicator operation signal. Determine. The steering wheel operation amount is calculated from the detection signal of the steering angle sensor. In addition, it is possible to determine the traveling state of the host vehicle in consideration of the driver's accelerator operation amount (acceleration state) and the like.

In the present embodiment, at least as the traveling situation of the host vehicle,
(1) There is a forward vehicle in a predetermined area in front, the vehicle is approaching the vehicle ahead and is about to pass the vehicle ahead;
(2) There is a front vehicle in a predetermined area ahead, and the vehicle is following the front vehicle at substantially the same speed,
(3) The situation is other than (1) and (2) above.
Is going to be judged.

  The required margin driving force calculation unit 40 calculates the required margin driving force to be secured each time based on the traveling state of the host vehicle determined by the traveling state determination unit 30 in addition to the accelerator operation amount and the vehicle speed. In the present embodiment, a normal mode, a high margin driving force traveling mode, and a low margin driving force traveling mode are provided as the margin driving force setting modes, and any mode is selected according to the traveling state of the host vehicle each time. Is to be selected.

  The required gear stage calculation unit 50 calculates the required gear stage based on the required driving force calculated by the required driving force calculation unit 10, the required margin driving force calculated by the required margin driving force calculation unit 40, and the like.

  The engine operating parameter calculation unit 60 is configured to perform various engine operating parameters based on the required driving force calculated by the required driving force calculation unit 10, the required margin driving force calculated by the required margin driving force calculation unit 40, the actual gear ratio, and the like. Is calculated. The actual gear ratio is a gear ratio realized by the required gear stage calculated by the required gear stage calculation unit 50.

  Next, among the functional blocks, details of the traveling state determination unit 30, the required margin driving force calculation unit 40, the required gear stage calculation unit 50, and the engine operation parameter calculation unit 60 will be described in order. FIG. 2 is a flowchart showing in detail the calculation process of the traveling state determination unit 30. In this process, the traveling state of the host vehicle is determined, and the high margin driving force traveling flag and the low margin driving force traveling flag are appropriately turned ON or OFF according to the traveling state.

  In FIG. 2, in step S101, the presence or absence of a forward vehicle is determined based on forward vehicle information from a laser radar sensor or the like, and in the subsequent step S102, whether or not the inter-vehicle distance from the forward vehicle is smaller than a predetermined threshold value K1. Is determined. If there is no preceding vehicle or if there is a preceding vehicle and the inter-vehicle distance ≧ K1, the process proceeds to step S110, and both the high margin driving force traveling flag and the low margin driving force traveling flag are turned OFF.

  If both steps S101 and S102 are YES, in step S103, it is determined whether or not the relative speed between the host vehicle and the preceding vehicle is equal to or less than a predetermined threshold value K2. Here, when the threshold value K2 is a negative value (K2 <0) and the relative speed ≦ K2, it is determined that the host vehicle and the preceding vehicle are separated. In this case, the process proceeds to step S110, and both the high margin driving force traveling flag and the low margin driving force traveling flag are turned OFF. In other words, the driver may request acceleration in order to reduce the inter-vehicle distance with the preceding vehicle, but it may continue the current driving state without requesting acceleration, so the determination of the driving situation is uncertain. The flag is cleared and this process is terminated.

  In step S104, it is determined whether or not the relative speed between the host vehicle and the preceding vehicle is equal to or greater than a predetermined threshold value K3. Here, when the threshold value K3 is a positive value (K3> 0) and the relative speed ≧ K3, it is determined that the host vehicle and the preceding vehicle are in a state of approaching. In this case, the process proceeds to step S105, and it is determined whether or not the course of the host vehicle is being changed, that is, whether or not the driver is going to pass the preceding vehicle. Specifically, the course change status is determined based on the steering angle information, the operation information of the direction indicator, and the like. When the route is changed, step S105 is set to YES in a period from when overtaking is started along with the route change until the own vehicle overtakes the preceding vehicle.

  If the host vehicle and the vehicle ahead are close to each other and the course is being changed, the process proceeds to step S106, and the high margin driving force travel flag is set to ON. If the course is not changed, the process proceeds to step S110, and both the high margin driving force traveling flag and the low margin driving force traveling flag are turned OFF. That is, even if the host vehicle and the preceding vehicle are approaching each other, if the course has not been changed, it is uncertain whether or not the vehicle will overtake in the future, so each flag is cleared and the process is terminated.

  Further, when K2 <relative speed <K3 (when both steps S103 and S104 are NO), the host vehicle is traveling at substantially the same speed as the preceding vehicle. In such a situation, the process proceeds to step S107. It is determined whether or not the course of the vehicle is being changed, that is, whether or not the driver is overtaking the vehicle ahead. If the speed is substantially the same as that of the preceding vehicle and the course is not changed, it can be determined that the host vehicle is following the preceding vehicle. During this follow-up running, delay processing is performed in step S108, and then in step S109, the low margin driving force running flag is turned ON. That is, when the host vehicle travels following the preceding vehicle, the mode shift is performed after a predetermined time delay when shifting from the normal mode or the like to the low margin driving force mode.

  If the speed is substantially the same as that of the preceding vehicle and the course is being changed, the process proceeds to step S110, and both the high margin driving force traveling flag and the low margin driving force traveling flag are turned OFF. In other words, if it is almost the same speed as the preceding vehicle and the course is changing, it may be a simple lane change or destination change instead of overtaking, and it is uncertain about the driving situation. Exit.

  Next, FIG. 3 is a diagram showing details of the required margin driving force calculation unit 40. In the configuration of FIG. 3, the maximum driving force is calculated according to the vehicle speed, and the maximum marginal driving force is calculated by subtracting the required driving force from the maximum driving force. The maximum driving force is calculated as a smaller value as the vehicle speed is higher. Further, an allowance driving force index is calculated based on the accelerator operation amount and the vehicle speed, and an allowance driving force base value is calculated by multiplying the margin driving force index and the maximum allowance driving force. On the other hand, a margin driving force correction amount is calculated based on the traveling state of the host vehicle determined by the traveling state determination unit 30 (each flag set in the processing of FIG. 2), and this margin driving force correction amount is calculated as the margin driving force. The required margin driving force is calculated by adding to the force base value. At this time, if the high margin driving force travel flag is ON in the processing of FIG. 2 (that is, in the high margin driving force traveling mode), a positive margin driving force correction amount is calculated and the margin driving force base value is calculated. Is corrected to the increasing side. If the low margin driving force travel flag is ON (that is, in the low margin driving force traveling mode), the negative margin driving force correction amount is calculated, and the margin driving force base value is corrected to the decreasing side. . If the high margin driving force running flag and the low margin driving force running flag are both OFF (that is, in the normal mode), the margin driving force correction amount is set to 0, and the margin driving force base value is not corrected.

  FIG. 4 is a diagram showing details of the required gear stage calculation unit 50. In the configuration of FIG. 4, the maximum possible turbine torque is calculated based on the torque converter turbine rotation speed, and each gear ratio of the first to fifth gears of the automatic transmission is extracted as one vector signal by the multiplexer (MUX). . Also, the maximum possible output shaft torque is calculated by multiplying the maximum possible turbine torque and the MUX vector signal, and the maximum possible axle torque is calculated by multiplying it by the differential ratio. The maximum possible margin driving force is calculated by subtracting the force. By this series of processing, the maximum possible margin driving force corresponding to each gear ratio of 1st speed to 5th speed is calculated.

  Then, the maximum possible margin driving force corresponding to each gear ratio of the first to fifth gears and the required margin driving force calculated by the required margin driving force calculation unit 40 (see FIG. 3) are respectively compared in magnitude. A value that satisfies “maximum possible margin driving force> required margin driving force” is extracted. Moreover, after reflecting each gear stage information in the extraction result, the highest gear stage is set as the required gear stage.

  FIG. 5 is a diagram showing details of the engine operation parameter calculation unit 60. In the configuration of FIG. 5, the target throttle opening and the target fuel amount are calculated as engine operating parameters. First, the required driving force is converted into the required engine torque. More specifically, the required engine torque is calculated using the following equation (1).

上記（１）式において、トルクコンバータトルク比は、トルクコンバータの出力軸トルクと入力軸トルクの比（＝出力軸トルク／入力軸トルク）であり、例えば図６の関係に基づいて算出される。図６において、トルクコンバータ速度比はトルクコンバータの出力軸回転数（トランスミッション入力回転数）と入力軸回転数（エンジン回転数）との比（出力軸回転数／入力軸回転数）である。

In the above equation (1), the torque converter torque ratio is the ratio of the output shaft torque and the input shaft torque of the torque converter (= output shaft torque / input shaft torque), and is calculated based on the relationship of FIG. In FIG. 6, the torque converter speed ratio is a ratio (output shaft speed / input shaft speed) between the output shaft speed (transmission input speed) and the input shaft speed (engine speed) of the torque converter.

  Then, the required air amount is calculated based on the required engine torque and the engine speed, and the target throttle opening is calculated based on the required air amount.

  Further, the required margin driving force is converted into the required margin engine torque. This conversion method is the same as the conversion of the required engine torque. Then, the target air-fuel ratio is calculated based on the required engine torque and the required margin engine torque, and the target fuel amount is calculated based on the target air-fuel ratio and the cylinder air charge amount.

  According to the embodiment described above in detail, the following excellent effects can be obtained.

  Since the running situation of the host vehicle including the relative relationship with the preceding vehicle is determined and the required margin driving force is increased or decreased based on the determined running situation of the host vehicle, the excess or deficiency of the margin driving force is eliminated. As a result, the fuel consumption can be reduced. In addition, excessive noise can be prevented. Further, with the optimization of the margin driving force, the operating state of the engine and the automatic transmission can be kept optimal.

  In addition, in order to determine the driving situation of the host vehicle based on the inter-vehicle distance, relative speed, steering wheel operation amount, and direction indicator operation information with the preceding vehicle, the driver's driving psychology is correctly determined, and this is used for driving force control. Can be reflected.

  If the driving situation is that the vehicle is following the vehicle without changing the course (that is, without overtaking the vehicle ahead), the low margin driving force driving mode is set to reduce the required margin driving force. Therefore, fuel consumption can be reduced in a driving situation where the possibility of future acceleration is low. It is also possible to realize quiet vehicle driving.

  Further, if the vehicle is in a driving situation overtaking the preceding vehicle, the driving mode is set to the high margin driving force driving mode, and the required margin driving force is increased. Therefore, it is possible to appropriately reflect the driver's acceleration intention in a driving situation where a quick acceleration response is required for overtaking.

  When the mode is shifted to the high margin driving force driving mode, the mode is shifted immediately, whereas when the mode is shifted to the low margin driving force driving mode, a delay process is performed so that the driving state can be changed by the driver (overtaking operation, etc.). The marginal driving force is actually reduced after the performance is lowered. As a result, it is possible to immediately respond to changes in the driving situation by the driver immediately after the start of follow-up driving.

  In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

  The configuration of the required margin driving force calculation unit 40 may be changed as shown in FIG. In the configuration of FIG. 7, the required margin driving force is calculated based on the accelerator operation amount and the vehicle speed with reference to the demand margin driving force map for each of the high margin driving force traveling mode, the low margin driving force traveling mode, and the normal mode. . Then, the calculated value of each mode is switched and used according to the traveling state of the host vehicle (specifically, the state of the high margin driving force traveling flag and the low margin driving force traveling flag). In this case, the margin driving force is set to be larger in the high margin driving force traveling mode and the margin driving force is set to be smaller in the low margin driving force traveling mode than the margin driving force (map value) in the normal mode. It has become. In addition, the structure which refers to a map about one mode selected according to the driving | running | working condition of the own vehicle may be sufficient.

  When the host vehicle changes the course, it is possible to set the high margin driving force travel mode until the predetermined time elapses from the start of the course change so as to increase the margin driving force.

  The presence of another vehicle in a predetermined side area or a predetermined rear area of the host vehicle may be detected, and the marginal driving force may be increased or decreased according to the relative relationship with the other vehicle. For example, when the inter-vehicle distance with another vehicle existing in the predetermined side area or the predetermined rear area of the host vehicle is reduced, the high margin driving force traveling mode is set to increase the margin driving force. Thereby, when the own vehicle and other vehicles approach too much and the driver notices it, quick danger avoidance traveling is enabled.

It is a functional block diagram of ECU regarding the driving force control of a vehicle. It is a flowchart which shows the calculation process of a driving | running | working condition determination part in detail. It is a figure which shows the detail of a required margin drive force calculation part. It is a figure which shows the detail of a request | requirement gear stage calculation part. It is a figure which shows the detail of an engine operation parameter calculation part. It is a figure for calculating a torque converter torque ratio. It is a figure which shows another structure of a required margin drive force calculation part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Required driving force calculation part, 20 ... Forward vehicle recognition part, 30 ... Driving condition determination part, 40 ... Required margin driving force calculation part.

Claims (5)

A means for calculating the required driving force of the vehicle in response to the driver's request in each case, and a means for calculating a marginal driving force in preparation for a future acceleration request, based on these required driving force and marginal driving force In the vehicle running state control device for controlling the vehicle running state,
A traveling state determination means for determining a traveling state of the host vehicle including a relative relationship with other vehicles traveling around;
A margin driving force increasing / decreasing means for increasing or decreasing the margin driving force based on the determined traveling state of the host vehicle;
With
The margin driving force increasing / decreasing means increases the margin driving force when the traveling state determining means determines that the other vehicle traveling around the host vehicle and the host vehicle are approaching each other. A vehicle running state control device.   When the traveling state determination means determines that the vehicle is following the vehicle without overtaking another vehicle existing in a predetermined area in front of the host vehicle, the margin driving force increase / decrease unit reduces the margin driving force. The vehicle running state control device according to claim 1.   The traveling state determination means is in a state in which the host vehicle is traveling at substantially the same speed with respect to another vehicle in a predetermined front area and is traveling following the other vehicle when the course of the host vehicle is not changed. The vehicle travel state control device according to claim 2 for determination.   4. The margin driving force increase / decrease means increases the margin driving force when the traveling state determination means determines that the vehicle is overtaking another vehicle existing in a predetermined area in front of the host vehicle. The vehicle travel state control device according to any one of the above.   5. The driving condition determination unit according to claim 4, wherein when the host vehicle is approaching another vehicle in a predetermined area in front and the course of the host vehicle is changed, it is determined that the vehicle is overtaking the other vehicle. Vehicle running state control device.

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