JP5257647B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicle travel control device that controls a vehicle so that the safe travel state of the vehicle is not impaired.

  In a vehicle equipped with an automatic transmission, it is possible to accelerate the vehicle using only the accelerator pedal without operating the clutch pedal. For this reason, when the vehicle is parked, the driver may mistakenly press the accelerator pedal and the brake pedal, resulting in an unexpected acceleration state. In a vehicle that requires a clutch operation by the driver, the clutch is not properly engaged in such a case, so that a so-called engine stall occurs and the vehicle stops. However, in a vehicle equipped with an automatic transmission, since the vehicle does not stop in this way, another countermeasure is required.

  Patent Document 1 shown below discloses a technique of a control device that automatically switches the shift stage of an automatic transmission in such a case. If it is determined that the safe running state has been lost when the vehicle is in the reverse running state, the control device cancels the state in which the vehicle can run regardless of the switching command to the automatic transmission. The determination that the safe driving state has been lost is that the vehicle has exceeded the predetermined vehicle speed, the accelerator pedal depression change amount has exceeded the predetermined change amount, and the engine speed has exceeded the predetermined speed. , Etc. are performed as determination conditions. Moreover, the cancellation | release of the state which can drive | work is performed by changing a shift position into neutral or parking, for example. The control device further controls the fuel injection device together with the change of the shift position to stop fuel injection into the combustion chamber of the engine.

JP 2003-65430 A (paragraphs 43 to 49, etc.)

  When the control device of Patent Literature 1 determines that the safe running state has been lost when the vehicle is in the backward running state, the control device automatically cancels the state in which the vehicle can run. Since the vehicle is stopped without notifying the driver of an error in the driving operation, there is still a possibility that the driver erroneously performs the driving operation. Further, since the vehicle is automatically stopped, there is a possibility that the driver feels uncomfortable when the driver performs control that is excessive. Furthermore, since the control device of Patent Document 1 performs the above-described control when the vehicle is in the backward running state, it cannot cope with the case where the driver makes the vehicle run erroneously at the shift position. In other words, when the driver moves the vehicle assuming that the shift lever for changing the gear position of the transmission is in the reverse position even though the shift lever is in the forward position, the control device of Patent Document 1 cannot cope with it.

  The invention of the present application was devised in view of the above problems, and controls the vehicle so that the safe driving state of the vehicle is not impaired due to an erroneous operation of the shift lever of the driver or an erroneous depression of the pedal. An object of the present invention is to provide a vehicle travel control device that can make a driver understand the vehicle without a sense of incongruity.

In order to achieve the above object, the characteristic configuration of the vehicle travel control apparatus according to the present invention is as follows:
A speed detector for detecting the speed of the vehicle;
An acceleration detector for detecting the acceleration of the vehicle;
The acceleration of the vehicle lies in the speed of the vehicle is provided with an acceleration limiting unit to limit within set upper limit acceleration to higher value speed of the vehicle is increased to reach a predetermined speed.

  According to this characteristic configuration, the acceleration limiting unit limits the acceleration of the vehicle within the upper limit acceleration set according to the speed of the vehicle. By limiting the acceleration of the vehicle, the vehicle is controlled so that the safe driving state of the vehicle is not impaired due to an erroneous operation of the shift lever of the driver or an erroneous depression of the pedal. At this time, since the acceleration is limited but not stopped, the vehicle can continue to advance. In other words, the possibility that the driver feels uncomfortable when the driver performs excessive control is reduced. Further, from the behavior of the vehicle that proceeds more slowly than the driving operation by the driver, the driver can understand the error of the driving operation without a sense of incongruity.

  In general, during normal driving, one of the accelerator pedal and the brake pedal is consciously used by the driver, and the driver is unlikely to make a mistake in pressing the pedal. Further, since the gear stage is not switched between forward and reverse during traveling, the vehicle does not travel in the wrong direction due to an erroneous operation of the shift lever that changes the gear stage of the transmission. That is, the driver's mistake in operating the shift lever or the pedal is almost always generated when the vehicle is stopped. According to this characteristic configuration, when the vehicle speed is low, such as immediately after the vehicle starts accelerating from the stop state, the upper limit acceleration is set to a low value, and when the vehicle speed is high such as when the vehicle is cruising. The upper limit acceleration is set to a high value. Therefore, during normal driving, the possibility that the acceleration is limited is reduced, and comfortable driving is not hindered. On the other hand, it is satisfactorily suppressed that the safety state of the vehicle is impaired due to an erroneous operation of the shift lever or an erroneous stepping on the pedal that may occur when the vehicle is at a low speed.

In addition, a vehicle travel control device according to the present invention includes:
Until the speed of the vehicle reaches a predetermined speed, the lower the speed of the vehicle, the lower the upper limit acceleration is set to be easier to limit the acceleration of the vehicle, and the higher the speed of the vehicle is, the higher the speed is. It is difficult to limit the acceleration of the vehicle by setting the upper limit acceleration high,
When the speed of the vehicle exceeds a predetermined speed, the acceleration of the vehicle is not limited.

As described above, an error in the operation of the shift lever by the driver or an error in stepping on the pedal often occurs when the vehicle is stopped. Therefore, when the vehicle speed is high, such as when the vehicle is cruising, the need to limit acceleration is very low. According to this characteristic configuration, when the speed of the vehicle exceeds a predetermined speed, the acceleration of the vehicle is not limited . Therefore, the acceleration is not restricted during normal running and comfortable running is less likely to be hindered, and the acceleration is restricted during low-speed running such as parking, so that it is difficult to deviate from the safe state.

In addition, a vehicle travel control device according to the present invention includes:
A traveling direction detector for detecting the traveling direction of the vehicle;
The acceleration limiting unit limits the acceleration of the vehicle within the upper limit acceleration set to a different value depending on the detected traveling direction of the vehicle.

  For example, when the traveling direction of the vehicle is forward, there is a high possibility of shifting to normal traveling, but when the traveling direction of the vehicle is backward, there is almost no transition to normal traveling. Therefore, it can be considered that there are many cases of normal traveling when the traveling direction is forward, and parking or turning off when the traveling direction is backward. Incorrect operation of the shift lever or incorrect pedal depression often occurs when parking or turning over rather than during normal driving. According to this feature configuration, the acceleration of the vehicle is limited within the upper limit acceleration set to a different value depending on the traveling direction. Therefore, for example, it is possible to set the upper limit acceleration at the time of reverse, which is considered to be highly likely to cause an erroneous operation of the shift lever or an erroneous depression of the pedal, to a low value. Since an appropriate upper limit acceleration is set for each of the normal traveling and the low-speed traveling such as parking, the comfortable traveling is not hindered and the safety can be maintained.

In addition, a vehicle travel control device according to the present invention includes:
A traveling direction detector for detecting a traveling direction of the vehicle;
An attitude detection unit for detecting the attitude of the driver of the vehicle,
The acceleration limiting unit limits the acceleration of the vehicle within the upper limit acceleration set to a different value depending on the detected traveling direction of the vehicle and the posture of the driver.

  For example, when the traveling direction of the vehicle is forward, there is a high possibility of shifting to normal traveling, but when the traveling direction of the vehicle is backward, there is almost no transition to normal traveling. Accordingly, it can be considered that the vehicle travels normally when the traveling direction is forward, and is parked or turned off when the traveling direction is backward. The driver's posture is a posture in which the driver's face is facing forward when the traveling direction of the vehicle is forward, and is facing backward when the vehicle is moving backward. When the driver misoperates the shift lever, the vehicle may move forward although the driver is facing backward. According to this characteristic configuration, the acceleration of the vehicle is limited within the upper limit acceleration set to a different value depending on the traveling direction of the vehicle and the posture of the driver. Therefore, as described above, when it is considered that there is a high possibility that the operation of the shift lever is wrong, the safety can be improved by setting the upper limit acceleration to a low value. On the other hand, when both the traveling direction of the vehicle and the posture of the driver indicate forward movement, comfortable traveling can be prevented from being hindered by setting the upper limit acceleration to a high value.

  In the vehicle travel control apparatus according to the present invention, the travel direction detection unit detects the travel direction of the vehicle based on a position of a shift lever that changes a gear position of the transmission of the vehicle. To do.

  The traveling direction detection unit can also detect the traveling direction based on, for example, the rotational direction of the wheel. However, if the traveling direction is detected based on the position of the shift lever as in this characteristic configuration, the traveling direction can be detected before the vehicle actually starts moving. The acceleration limiting unit is preferable because it can set the upper limit acceleration according to the traveling direction at an early stage.

In addition, a vehicle travel control device according to the present invention includes:
A braking control unit for controlling the braking device of the vehicle;
A fuel supply control unit that controls the supply of fuel to the engine of the vehicle,
The acceleration limiting unit limits the acceleration of the vehicle by controlling one or both of the braking control unit and the fuel supply control unit.

  Under the control of the braking control unit, the braking device can be operated to favorably limit the acceleration. Further, the control of the fuel supply control unit can suppress the engine output and limit the acceleration satisfactorily. According to this characteristic configuration, one or both of the braking control unit and the fuel supply control unit are controlled by the acceleration limiting unit, so that the acceleration of the vehicle is satisfactorily limited.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of a vehicle travel control apparatus 10 according to the present invention. FIG. 2 is a graph showing an example of the relationship between the speed and the upper limit acceleration. As shown in FIG. 1, the travel control device 10 includes an acceleration limiting unit 1, a speed detection unit 2, an acceleration detection unit 3, a traveling direction detection unit 5, an attitude detection unit 6, a braking control unit 8, Each function part with the fuel supply control part 9 is provided. The travel control apparatus 10 is configured with a processor such as a microcomputer or a DSP (digital signal processor) as a core. Each functional unit is realized by cooperation between a processor and a program executed by the processor. In other words, each functional unit shows a sharing of functions and does not need to be physically provided independently.

  The acceleration limiting unit 1 is a functional unit that limits the vehicle acceleration a within the upper limit acceleration L shown in FIG. Although details will be described later, the upper limit acceleration L is set according to the speed of the vehicle shown on the horizontal axis of FIG. When the acceleration of the vehicle exceeds the upper limit acceleration L like the acceleration a2 shown in FIG. 2, the acceleration limiting unit 1 limits the acceleration within the upper limit acceleration L like the acceleration a1.

  The speed detection unit 2 is a functional unit that detects the speed of the vehicle. The speed is measured by a rotation sensor 21 installed in the vicinity of the vehicle wheel. The speed detection unit 2 detects the speed of the vehicle by performing a calculation based on the measurement result of the rotation sensor 21.

  The acceleration detection unit 3 is a functional unit that detects the acceleration of the vehicle. The acceleration is detected by differentiating the vehicle speed. That is, the acceleration is detected by calculating the speed based on the measurement result of the rotation sensor 21 and differentiating the calculated speed. In the block diagram shown in FIG. 1, the acceleration is detected from the measurement result of the rotation sensor 21 as described above. However, the acceleration may be calculated by receiving speed information from the speed detection unit 2. In addition to the rotation sensor 21, a sensor for measuring acceleration such as a G sensor may be provided to detect the acceleration.

  The traveling direction detection unit 5 is a functional unit that detects the traveling direction of the vehicle. An output of the shift lever switch 25 is input to the traveling direction detection unit 5. The shift lever switch 25 is a switch that is operated by the driver and detects the shift position of the shift lever that changes the gear position of the transmission. The shift lever switch 25 has, for example, a shift position in a forward position (drive: D range), a neutral position (neutral: N range), a reverse position (reverse: R range), a parking position (parking: P range), etc. Is output to the traveling direction detector 5. When the traveling direction detection unit 5 receives an output indicating that it is in the D range from the shift lever switch 25, the traveling direction detection unit 5 detects that the traveling direction of the vehicle is the forward direction. Further, when the traveling direction detection unit 5 receives an output indicating that the vehicle is in the R range from the shift lever switch 25, the traveling direction detection unit 5 detects that the traveling direction of the vehicle is the backward direction.

  The posture detection unit 6 is a functional unit that detects the posture of the driver. The posture detection unit 6 receives image data captured by the in-vehicle camera 26. The camera 26 is installed on, for example, a steering column, an instrument panel, a room mirror, and the like, and photographs the face of the driver who is seated on the driver's seat in a normal driving posture. The posture detection unit 6 estimates the position of the face at the reference position in the image data, and recognizes locations such as eyes, nose, and mouth using known image processing such as edge detection. Next, the posture detection unit 6 calculates the center position of the face from the recognized coordinates of the eyes, nose, mouth, and the like. Then, the posture detection unit 6 determines that the driver is facing forward when the calculated angle between the center position and the reference position is less than 45 degrees, and faces backward when the angle is 45 degrees or more. It is determined that

  The braking control unit 8 is a functional unit that controls the braking device 28 of the vehicle. The braking control unit 8 is controlled by the acceleration limiting unit 1 and drives the braking device 28 to limit the acceleration of the vehicle.

  The fuel supply control unit 9 is a functional unit that controls the fuel injection device 29 that supplies fuel to the engine of the vehicle to control the supply of fuel to the engine. By the control of the fuel supply control unit 9, the output of the engine is suppressed and the acceleration is limited.

  Hereinafter, an example in which the acceleration a of the vehicle is limited within the upper limit acceleration L set according to the speed of the vehicle will be described with reference to FIGS. A straight line indicated by a symbol L in FIG. 2 is an example of the upper limit acceleration L set according to the speed of the vehicle. The upper limit acceleration L is set to a higher value as the vehicle speed increases. In the example shown in FIG. 2, the upper limit acceleration L is higher in proportion to the vehicle speed.

  In most cases, the driver misoperates the shift lever or steps on the pedal when the vehicle is stopped. In general, during normal driving, the driver is unlikely to make a mistake in pressing the accelerator pedal and the brake pedal. Further, the gear stage is not switched between forward and reverse during traveling. Conversely, there are cases where it is desired to increase the acceleration rapidly when climbing or overtaking during normal driving. As shown in FIG. 2, the upper limit acceleration L is set higher as the vehicle speed increases, so that the acceleration a is less likely to be restricted when the vehicle is traveling normally, and comfortable traveling is not hindered. On the other hand, sudden acceleration due to a shift lever operation mistake or a pedal depression mistake that may occur when the vehicle is at a low speed is suppressed by the upper limit acceleration L set to a low value. Therefore, it is possible to satisfactorily suppress the vehicle from being damaged by such rapid acceleration.

  The upper limit acceleration L is set based on the behavior of the vehicle when it is safe, that is, the acceleration and speed when the vehicle travels safely are obtained by experiments and simulations, and the upper limit acceleration L is set based on the results. Is done. As described above, the travel control device 10 is configured with a processor such as a microcomputer as a core. Accordingly, the upper limit acceleration L is preferably stored as a map of speed and acceleration in a storage medium such as a nonvolatile memory. Alternatively, if the upper limit acceleration L can be expressed by a simple expression such as a linear expression or a quadratic expression, the expression may be stored in a storage medium and calculated by a processor.

  In FIG. 2, only one type of upper limit acceleration L is illustrated, but a plurality of upper limit accelerations L may be set according to conditions. For example, as described above, the traveling direction detection unit 5 detects the traveling direction of the vehicle. Large acceleration is not necessary when going backwards. Therefore, when the vehicle moves backward, it is preferable to select the upper limit acceleration L having a lower value than when moving forward.

  In addition, when the upper limit acceleration L is linear with respect to the speed as shown in FIG. 2, the slope may be different with the intercept being the same value during forward movement and backward movement. That is, at the time of low speed, a large difference may not be provided in the upper limit acceleration L between the forward time and the reverse time, but a difference may be generated in the upper limit acceleration L as the speed increases.

  Further, the upper limit acceleration L may be set based on the detection result of the posture detection unit 6. As described above, the attitude detection unit 6 detects whether the driver is facing forward or backward. The acceleration limiting unit 1 preferably limits the acceleration based on the upper limit acceleration L when moving forward when the driver is facing forward, and based on the upper limit acceleration L when moving backward when facing the rear. is there.

  More preferably, the acceleration limiting unit 1 limits the acceleration a based on the upper limit acceleration L set based on the detection results of both the traveling direction detection unit 5 and the posture detection unit 6. When the driver has made a shift error, the forward direction detection unit 5 may detect “forward” and the posture detection unit 6 may detect “reverse”. Thus, when there is a high possibility that the driver has made a shift error, for example, the acceleration a is preferably limited based on the upper limit acceleration L having a lower value than usual. In this case, since the vehicle moves in a direction that the driver does not expect, safety can be improved by limiting the acceleration a.

  As shown in FIG. 2, the upper limit acceleration L is set higher as the speed of the vehicle becomes higher, so that the acceleration a can be made less likely to be restricted when the vehicle is traveling normally. Here, the upper limit acceleration L may be infinite when the speed of the vehicle is equal to or higher than a predetermined speed (limit speed). That is, as shown in FIG. 3, until the vehicle reaches the speed limit V1, an upper limit acceleration L that is a high value according to the speed is set in the same manner as in FIG. When the vehicle reaches the speed limit V1, the upper limit acceleration L is set to infinity according to this speed, and the acceleration limiting unit 1 does not substantially limit the acceleration a. In other words, the acceleration limiting unit 1 limits the acceleration a of the vehicle until the vehicle reaches a predetermined speed limit V1 from a stopped state (speed is zero).

  The acceleration limiting unit 1 may limit the acceleration a of the vehicle until a predetermined time limit elapses after the acceleration is started, not until the vehicle reaches the speed limit V1 from the stop state. As described above, an error in the operation of the shift lever by the driver or an error in stepping on the pedal often occurs when the vehicle is stopped. Therefore, the necessity of limiting the acceleration a becomes very low when the vehicle reaches a cruise from the stop state through the acceleration period and the speed of the vehicle is high. Therefore, when the vehicle starts accelerating and the predetermined time limit elapses, the acceleration limiting unit 1 can consider that the vehicle has reached the cruise state and can cancel the acceleration limitation.

  When the acceleration limiting unit 1 limits the acceleration a of the vehicle only until the vehicle reaches the speed limit V1 from the stop state, the upper limit acceleration L may be a constant value. That is, as shown in FIG. 4, two types of upper limit accelerations L of a finite value and infinity may be switched according to the speed of the vehicle.

  Further, the upper limit acceleration L does not need to continuously increase with respect to the speed as shown in FIGS. 2 and 3, and may increase stepwise as shown in FIG. FIG. 5 illustrates an upper limit acceleration L that increases stepwise up to the limit speed V1 and becomes infinite when the limit speed V1 is reached. However, the present invention is not limited to this, and the upper limit acceleration L may continue to increase stepwise as in FIG.

  The upper limit acceleration L shown in FIG. 6 is a modification of the upper limit acceleration L shown in FIG. The upper limit acceleration L shown in FIG. 2 increases linearly with respect to the vehicle speed, but the upper limit acceleration L shown in FIG. 6 increases nonlinearly. Here, the upper limit acceleration L is illustrated as an example of a gentle increase when the vehicle speed is low and a rapid increase as the vehicle speed increases. As described above, an error in the operation of the shift lever by the driver or an error in stepping on the pedal often occurs when the vehicle is stopped. Therefore, when the speed of the vehicle is low, it is preferable that the value of the upper limit acceleration L is set low and the acceleration a is easily limited by the acceleration limiting unit 1. The upper limit acceleration L shown in FIG. 6 is preferable because it is maintained at a low value when the vehicle is at a low speed.

  On the other hand, as described above, when the vehicle speed is high, such as when the vehicle is traveling normally, the necessity of limiting the acceleration a is very low. In particular, during normal driving, there is a case where it is desired to increase the acceleration rapidly when climbing or overtaking. As shown in FIG. 6, as the vehicle speed increases, the upper limit acceleration L is rapidly set higher, so that the acceleration a is less likely to be limited when the vehicle is traveling normally. Moreover, it becomes easy to set the upper limit acceleration L to a high value that substantially cancels the limit of the acceleration a.

  As described above, the traveling control device 10 according to the present invention can control the vehicle so that the safe traveling state of the vehicle is not impaired by the driver's erroneous operation of the shift lever or the erroneous depression of the pedal. Moreover, the traveling control apparatus 10 can make a driver | operator surely understand the error of driving operation without a sense of incongruity. The travel control device 10 limits the acceleration, but does not limit the speed or stop the vehicle. Therefore, it is possible to reduce the possibility that the driver feels uncomfortable when the driver performs control that is excessive.

The block diagram which shows an example of a structure of the traveling control apparatus of the vehicle which concerns on this invention Graph showing an example of the relationship between speed and upper limit acceleration Graph showing an example of the relationship between speed and upper limit acceleration Graph showing an example of the relationship between speed and upper limit acceleration Graph showing an example of the relationship between speed and upper limit acceleration Graph showing an example of the relationship between speed and upper limit acceleration

1: Acceleration limiting unit 2: Speed detection unit 3: Acceleration detection unit 5: Traveling direction detection unit 6: Attitude detection unit 8: Braking control unit 9: Fuel supply control unit 28: Braking device

Claims (6)

A speed detector for detecting the speed of the vehicle;
An acceleration detector for detecting the acceleration of the vehicle;
The acceleration of the vehicle, travel control device for a vehicle speed of said vehicle is equipped with an acceleration limiting unit to limit within set upper limit acceleration to higher value speed of the vehicle is increased to reach a predetermined speed . Until the speed of the vehicle reaches a predetermined speed, the lower the speed of the vehicle, the lower the upper limit acceleration is set to be easier to limit the acceleration of the vehicle, and the higher the speed of the vehicle is, the higher the speed is. It is difficult to limit the acceleration of the vehicle by setting the upper limit acceleration high,
The travel control device for a vehicle according to claim 1 , wherein when the speed of the vehicle exceeds a predetermined speed, the acceleration of the vehicle is not limited . A traveling direction detector for detecting the traveling direction of the vehicle;
3. The vehicle travel control device according to claim 1, wherein the acceleration limiting unit limits the acceleration of the vehicle within the upper limit acceleration set to a different value depending on the detected traveling direction of the vehicle. . A traveling direction detector for detecting a traveling direction of the vehicle;
An attitude detection unit for detecting the attitude of the driver of the vehicle,
The acceleration limiting portion, within the upper limit acceleration which is set to a different value depending on the traveling direction and the posture of the driver of said detected vehicle, to limit the acceleration of the vehicle, according to claim 1 or 2 Vehicle travel control device. The traveling direction detection unit detects the traveling direction of the vehicle based on the position of the shift lever to change the gear position of the transmission of the vehicle, cruise control apparatus for a vehicle according to claim 3 or 4. A braking control unit for controlling the braking device of the vehicle;
A fuel supply control unit that controls the supply of fuel to the engine of the vehicle,
The travel control device according to any one of claims 1 to 5 , wherein the acceleration limiting unit limits the acceleration of the vehicle by controlling one or both of the braking control unit and the fuel supply control unit. .

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