JP2018103897A - Travel control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a travel control device that enables automatic travel more safely based on the credibility of a preceding vehicle, and can reduce uneasiness and dissatisfaction of a driver.SOLUTION: A travel control device includes detection means 20 for detecting a travelling state of a preceding vehicle travelling ahead of a vehicle, a determination part 30 for determining whether or not the travelling state corresponds to each of a plurality of factors that deteriorate credibility of the preceding vehicle, a credibility calculation part 40 for performing weighting based on the travelling state for each corresponding factor and calculating the credibility by summing up the weighting for each factor, and an automatic travel control part 50 for causing the vehicle to travel in different travel modes according to the credibility.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a travel control device, and more particularly, to a travel control device that controls travel of a host vehicle by changing a travel mode based on a travel state of a preceding vehicle.

  In recent years, cruise control functions (hereinafter referred to as ACC) that support driving operations have been adopted in automobiles. ACC is a function that supports the driving operation by following the vehicle while maintaining the distance between the vehicles according to the vehicle speed within the set vehicle speed.

  As a travel control device that realizes such a function, a device that predicts the driving characteristics of a preceding vehicle and controls the traveling of the host vehicle prior to various driving operations such as a brake operation performed on the preceding vehicle is known. (See Patent Document 1). For example, if the preceding vehicle is expected to perform a brake operation, the host vehicle also decelerates by performing a brake operation. In this way, the driving characteristics of the vehicle are predicted so that the vehicle travels in the same manner as the preceding vehicle.

  However, there is a problem when the preceding vehicle is not always reliable. Examples of leading vehicles that cannot be trusted include driving in a staggered direction and sudden acceleration / deceleration. In the prior art, the vehicle follows the vehicle regardless of whether the preceding vehicle can be trusted. Therefore, there is room for improvement in the safety of automatic driving, such as following the unreliable preceding vehicle without sufficient distance between the vehicles. In addition, when following an unreliable preceding vehicle, the passenger may be anxious or dissatisfied. Such a problem is not limited to follow-up running, but generally exists for automatic running control of automobiles.

JP 2008-87545 A

  The present invention has been made in view of such circumstances, and provides a travel control device that enables automatic travel more safely based on the reliability of a preceding vehicle, and that can reduce driver anxiety and dissatisfaction. With the goal.

  According to a first aspect of the present invention for solving the above-described problem, a detecting means for detecting a traveling state of a preceding vehicle traveling in front of the vehicle, and a plurality of factors that lower the reliability of the preceding vehicle, the traveling of the preceding vehicle. A determination unit that determines whether a state is applicable, a weighting unit that performs weighting based on the driving state for each of the corresponding factors, and a crediting degree calculation unit that calculates the crediting degree by summing the weighting for each factor; and And an automatic travel control unit that causes the vehicle to travel in different travel modes.

  In the first aspect, it is determined whether the traveling state of the preceding vehicle corresponds to a plurality of factors that lower the reliability. That is, it is determined whether or not the preceding vehicle is traveling so as to reduce the reliability, according to whether or not it corresponds to a plurality of predetermined factors. And if the travel control apparatus determines the factor which reduces reliability, it will weight each factor based on a driving | running | working state, and will calculate creditworthiness. This reliability is an index indicating how much the preceding vehicle can be trusted, and the vehicle can automatically travel with an appropriate inter-vehicle distance corresponding to the reliability.

  As described above, since the traveling control device performs automatic traveling control by switching the traveling mode based on the reliability, the safety of automatic driving is further enhanced, such as traveling sufficiently following the inter-vehicle distance with respect to a preceding vehicle having a low reliability. Can be improved. In addition, since it is possible to drive a vehicle with a low degree of reliability, such as following the vehicle with a sufficient distance between the vehicles, it is possible to prevent the driver from feeling uneasy or frustrated.

  According to a second aspect of the present invention, in the travel control device according to the first aspect, the factor is that the preceding vehicle moves laterally beyond a threshold value, or the preceding vehicle exceeds a threshold value. A traveling control device is characterized by being decelerated.

  In the second aspect, factors relating to driving characteristics such as lateral movement and driving that accelerates or decelerates beyond a threshold are used as factors that lower the reliability. By using the factor, it is possible to accurately determine that the preceding vehicle having a high possibility of giving the driver anxiety and dissatisfaction has a low reliability.

  According to a third aspect of the present invention, in the travel control device described in the first or second aspect, the factor is that an image obtained by imaging the appearance of the preceding vehicle conforms to a predetermined image pattern. It is in the traveling control apparatus characterized by being.

  In the third aspect, as a factor that lowers the reliability, an image obtained by imaging the appearance of the preceding vehicle is related to a driver such that the image conforms to a predetermined image pattern (for example, a beginner driving sign or an elderly driver sign). Use factors. By using the factor, it is possible to accurately determine that the preceding vehicle having a high possibility of giving the driver anxiety and dissatisfaction has a low reliability.

  According to a fourth aspect of the present invention, in the travel control device according to any one of the first to third aspects, the reliability calculation unit has a high frequency that the determination unit determines that the factor is applicable. There is a travel control device characterized by increasing the weighting of the factor.

  In the fourth aspect, if a factor that lowers the creditworthiness occurs frequently, the weighting of the factor is lowered in order to further reduce the creditworthiness of the preceding vehicle. As a result, it is possible to accurately calculate the reliability of the preceding vehicle that cannot be trusted.

  According to a fifth aspect of the present invention, in the travel control device according to any one of the first to fourth aspects, the reliability calculation unit uses different weights depending on a surrounding environment in which the vehicle is traveling. And calculating the reliability.

  In the fifth aspect, it is possible to calculate a more accurate reliability suitable for the surrounding environment.

  According to a sixth aspect of the present invention, in the travel control device according to the fifth aspect, when the preceding vehicle is traveling on a general road as the surrounding environment, the reliability calculating unit sets a threshold value for the preceding vehicle. In the travel control device, the weight given to the factor that accelerates or decelerates beyond is made heavier than the weight given to the factor that causes the preceding vehicle to move laterally beyond a threshold value.

  In the sixth aspect, when the surrounding environment is a general road, a factor related to acceleration / deceleration of the preceding vehicle is increased. As a result, it is possible to accurately determine that the preceding vehicle that travels suddenly in acceleration and deceleration that is considered dangerous on a general road has low reliability.

  According to a seventh aspect of the present invention, in the travel control device according to the fifth or sixth aspect, the reliability calculation unit is configured such that when the preceding vehicle is traveling on a highway as the surrounding environment, the preceding vehicle The travel control device is characterized in that the weight given to the factor that moves laterally beyond the threshold is made heavier than the weight given to the factor that the preceding vehicle accelerates and decelerates beyond the threshold.

  In the seventh aspect, when the surrounding environment is a highway, a factor related to the lateral movement of the preceding vehicle is increased. Accordingly, it is possible to accurately determine that the preceding vehicle that travels in the lateral direction, which is considered dangerous on the highway, or travels in the lateral direction has low reliability.

  According to an eighth aspect of the present invention, in the travel control device according to any one of the fifth to seventh aspects, when the reliability calculation unit is traveling at night as the surrounding environment, The travel control device is characterized in that a weight given to a factor related to a driver of the preceding vehicle is made heavier than a weight given to another factor.

  In the eighth aspect, when the surrounding environment is nighttime, the factor related to the driver of the preceding vehicle is increased. As a result, it is possible to accurately determine that the preceding vehicle driven by the driver considered to be dangerous at night has low reliability.

  According to a ninth aspect of the present invention, in the travel control device according to any one of the first to eighth aspects, the automatic travel control unit increases an inter-vehicle distance with respect to the preceding vehicle as the reliability is lower. A travel control device is characterized in that the vehicle is controlled to be wide.

  In the ninth aspect, since the vehicle travels with a margin with respect to a preceding vehicle with low reliability, the safety can be further improved, and the anxiety and dissatisfaction given to the driver can be more reliably reduced. be able to.

  According to a tenth aspect of the present invention, in the travel control device according to any one of the first to ninth aspects, the automatic travel control unit changes the lane when the reliability is equal to or less than a predetermined threshold. Thus, the vehicle is controlled so as to pass the preceding vehicle.

  In the tenth aspect, since the vehicle does not keep following the preceding vehicle with low reliability, the safety of the automatic driving can be further improved. In addition, it is possible to prevent anxiety and dissatisfaction of passengers by following such a preceding vehicle.

  According to an eleventh aspect of the present invention, in the travel control device according to any one of the first to tenth aspects, warning means for issuing a warning to a driver of the vehicle when the reliability is a predetermined threshold value or less. A travel control device comprising:

  In the eleventh aspect, the driver can be warned that the preceding vehicle cannot be trusted.

  ADVANTAGE OF THE INVENTION According to this invention, the traveling control apparatus which enables automatic driving | running | working more safely based on the reliability of a preceding vehicle, and can reduce a driver | operator's anxiety and dissatisfaction is provided.

It is a schematic block diagram of the vehicle which has an automatic running function. It is a figure showing the functional block of the traveling control apparatus which realizes an automatic traveling function. It is a flowchart explaining operation | movement of a traveling control apparatus. It is a flowchart explaining operation | movement of a traveling control apparatus. It is a flowchart explaining operation | movement of a traveling control apparatus.

  Hereinafter, modes for carrying out the present invention will be described. In addition, description of embodiment is an illustration and this invention is not limited to the following description.

<Embodiment 1>
FIG. 1 is a schematic configuration diagram of a vehicle having an automatic travel function, and FIG. 2 is a diagram illustrating functional blocks of a travel control device that realizes the automatic travel function. The vehicle 1 is equipped with a travel control device 10. The travel control device 10 is configured by a microcomputer including a central processing unit and a main storage device, and performs control of various parts and various calculations for controlling the engine of the vehicle 1.

  Furthermore, the traveling control device 10 calculates the reliability of a preceding vehicle that travels in front of the vehicle 1 and performs cruise control based on the reliability. In order to realize such a cruise control function based on the reliability of the preceding vehicle, the detection means 20 (forward radar 21, camera 22, image analysis unit 23), determination unit 30, reliability calculation unit 40, and automatic travel control unit 50. The image analysis unit 23, the determination unit 30, the reliability calculation unit 40, and the automatic travel control unit 50 are implemented by a program executed by the travel control device 10. Although not particularly illustrated, the vehicle 1 is provided with a switch for switching between starting and stopping automatic driving and an operation menu displayed on the display. When the driver operates these switches and operation menus, an instruction to start or stop automatic traveling is given to the traveling control device 10.

  The front radar 21 is an example of a detection unit that detects a traveling state of a preceding vehicle. Specifically, the front radar 21 is configured to perform various types such as a traveling speed in which the vehicle 1 is traveling and a traveling speed of a preceding vehicle in a traveling lane adjacent to the traveling lane, a distance between the vehicle 1 and the degree of acceleration and deceleration. It is a device that detects the running state. As such a forward radar 21, a known device such as a radar device using millimeter waves can be used.

  The camera 22 is a device that captures an image of the front including the road surface ahead in the traveling direction of the vehicle 1, the lane boundary line on the road surface, the preceding vehicle, and the like. An image captured by the camera 22 is transmitted to the travel control device 10.

  The image analysis unit 23 detects various information based on the running state and appearance of the vehicle 1 based on the image obtained from the camera 22. For example, by analyzing the image, it is possible to detect a running state such as which position (near the center or the left or right boundary line) the preceding vehicle is running on. In addition, various signs such as an initial driver sign and an elderly driver sign attached to the body surface of the preceding vehicle are detected from the image. Such image analysis can be realized by a known image processing method.

  As described above, the traveling speed of the preceding vehicle obtained by the front radar 21, the camera 22, and the image analysis unit 23, the distance between the vehicles, the degree of acceleration and deceleration, the traveling position, the presence / absence of the beginner driving style attached to the preceding vehicle, and the like Corresponds to the traveling state referred to in the present invention.

  The determination unit 30 determines whether the above-described traveling state corresponds to each of a plurality of factors. The factor is an element that causes a decrease in the reliability of the preceding vehicle. Examples of the factor include a factor related to the driving characteristics of the preceding vehicle (hereinafter referred to as driving characteristics factor) and a factor related to the driver of the preceding vehicle (hereinafter referred to as driver factor). Driving characteristic factors include driving in which the preceding vehicle has moved laterally beyond a threshold, driving that has been fluctuated by repeated reciprocation in the lateral direction, driving in which acceleration or deceleration has exceeded a threshold, and the like. Driver factors include driving by beginners or driving by elderly people.

  The determination unit 30 determines whether the traveling state obtained by the detection unit 20 corresponds to each of the driving characteristic factor and the driver factor. For example, the determination unit 30 determines whether the traveling position of the preceding vehicle obtained by the detection unit 20 has moved from the center of the lane to the lateral direction by a predetermined threshold or more. This is performed by obtaining the distance between the traveling position of the preceding vehicle obtained by image processing and the center of the lane and comparing the distance with a predetermined threshold.

  In addition, the determination unit 30 determines whether the traveling position of the preceding vehicle obtained by the detection unit 20 repeats the reciprocation in the lateral direction within a predetermined time by a predetermined threshold value or more. The determination unit 30 determines whether the acceleration or deceleration of the preceding vehicle obtained by the detection unit 20 exceeds a threshold value. Thus, the determination part 30 determines whether the driving state of a preceding vehicle corresponds to each driving characteristic factor.

  Further, the determination unit 30 determines whether the sign attached to the vehicle body surface of the preceding vehicle obtained by the detection means 20 is a beginner driving sign or an elderly driver sign set as a driver factor. In this manner, the determination unit 30 determines whether the traveling state of the preceding vehicle corresponds to each driver factor.

  The reliability calculation unit 40 performs weighting based on the driving state for each driving characteristic factor and driver factor determined to be applicable by the determination unit 30, and calculates the reliability by adding the weights assigned to these factors. . The trust level indicates the degree to which the preceding vehicle can be trusted.

  For example, it is assumed that the determination unit 30 determines from the traveling state of the preceding vehicle that the lateral movement is a driving characteristic factor and a beginner driving sign is a driver factor. The reliability calculation unit 40 weights these two factors. Since the factor is an element that lowers the creditworthiness, a negative weight is given. For example, as the amount of movement in the horizontal direction is larger, the absolute value is weighted with a larger negative value. In other words, a preceding vehicle that is driven with a large amount of movement in the lateral direction cannot be trusted, so the reliability is low.

  Further, a negative value set in advance is weighted to the driver factor of the beginner driving sign. Other driving characteristic factors and driver factors are determined not to be applicable by the determination unit 30, and therefore are not considered when calculating the creditworthiness.

  The reliability calculation unit 40 weights each factor determined to be applicable by the determination unit 30, sums the weights of the factors, and sets this as the reliability. There is no particular limitation on the weighting mode, and it is preferable to assign a lower weight to a factor that is estimated to have a high degree of lowering the reliability. Moreover, it is preferable that the weight of the factor is increased as the frequency at which the determination unit 30 determines that the factor is applicable is higher. For example, as the frequency of moving to a predetermined threshold or more in the horizontal direction increases, it is preferable to apply heavier weighting (weighting that lowers the reliability).

  The automatic traveling control unit 50 realizes a cruise control function, and based on the image obtained from the camera 22, the traveling state of the preceding vehicle obtained from the front radar 21, the state of the road surface, etc. Control is performed to drive the vehicle 1 at a constant vehicle speed while maintaining an appropriate inter-vehicle distance.

  Various parameters necessary for cruise control are set for each of a plurality of travel modes. The automatic travel control unit 50 selects one of a plurality of travel modes according to the reliability of the preceding vehicle, and performs cruise control using parameters set for each travel mode. An example of a parameter for performing cruise control is a distance between vehicles.

  For example, a standard inter-vehicle distance is set in the travel mode used when the reliability is high. On the other hand, in the driving mode used when the reliability is low, an inter-vehicle distance longer than the standard inter-vehicle distance is set.

  The operation of the travel control device 10 having the above-described configuration will be described. FIG. 3 is a flowchart for explaining the operation of the travel control device 10. First, the traveling control device 10 determines whether automatic driving is in progress (step S1). If the driver does not instruct the start of automatic driving (step S1: No), the subsequent processing is not performed (END). If the driver has instructed the start of automatic driving (step S1: Yes), the reliability of the preceding vehicle is calculated (step S2).

  As described above, the reliability is detected by the detecting means 20 to detect the traveling state of the preceding vehicle, the determination unit 30 determines whether the driving state corresponds to each of a plurality of factors, and the reliability calculation unit 40 determines the corresponding factor. It is obtained by weighting and summing.

  Then, the traveling control device 10 switches to the traveling mode corresponding to the reliability and performs automatic driving (cruise control) with the parameters (inter-vehicle distance) set in the traveling mode (step S3). For example, if the reliability is low, automatic driving is performed so as to increase the distance between the vehicles.

  As described above, the traveling control apparatus 10 according to the present embodiment determines whether the traveling state of the preceding vehicle corresponds to a plurality of factors that decrease the reliability. That is, it is determined whether or not the preceding vehicle is traveling so as to reduce the reliability, according to whether or not it corresponds to a plurality of predetermined factors.

  And if the traveling control apparatus 10 determines the factor which reduces a reliability, it will weight each factor based on a driving state, and will calculate a reliability. This reliability is an index indicating how much the preceding vehicle can be trusted, and the vehicle can automatically travel with an appropriate inter-vehicle distance corresponding to the reliability.

  Thus, since the traveling control apparatus 10 performs automatic traveling control by switching the traveling mode based on the reliability, the traveling control apparatus 10 can travel sufficiently following the inter-vehicle distance with respect to a preceding vehicle having a low reliability, and the safety of automatic driving. Can be improved. In addition, the preceding vehicle with low reliability is followed with a sufficient distance between the vehicles, so it is possible to prevent occupants from feeling uneasy or dissatisfied.

  In addition, the travel control device 10 according to the present embodiment uses driving characteristic factors such as lateral movement and driving that accelerates or decelerates beyond a threshold as factors that lower the reliability. The driving characteristic factor is likely to give anxiety and dissatisfaction to the driver of the vehicle 1. In other words, it is possible to accurately determine that the preceding vehicle having a high possibility of giving the driver anxiety and dissatisfaction has a low reliability.

  Further, in the travel control device 10 according to the present embodiment, an image obtained by imaging the appearance of the preceding vehicle is adapted to a predetermined image pattern (beginner driving sign or elderly driver sign) as a factor for reducing the reliability. Driver factors such as The driver factor is likely to give anxiety and dissatisfaction to the driver of the vehicle 1. In other words, it is possible to accurately determine that the preceding vehicle having a high possibility of giving the driver anxiety and dissatisfaction has a low reliability.

  In addition, the traveling control device 10 according to the present embodiment increases the weight of the factor as the frequency at which the factor is determined to be applicable by the determination unit 30 increases. That is, if a factor that lowers the creditworthiness occurs frequently, the weighting of the factor is lowered in order to further reduce the creditworthiness of the preceding vehicle. As a result, it is possible to accurately calculate the reliability of the preceding vehicle that cannot be trusted.

  Moreover, the traveling control apparatus 10 according to the present embodiment performs follow-up traveling control so that the inter-vehicle distance is increased with respect to the preceding vehicle as the reliability is lower. As a result, it is possible to follow the vehicle with a margin with respect to a preceding vehicle with low reliability, so that the safety can be further improved, and the anxiety and dissatisfaction given to the driver can be more reliably reduced. .

<Embodiment 2>
In the first embodiment, the traveling control device 10 calculates the reliability based on the traveling state of the preceding vehicle, but is not limited to such an aspect. For example, the reliability may be calculated based on the surrounding environment in which the vehicle 1 is traveling and the traveling state of the preceding vehicle.

  As the surrounding environment, for example, the type of road on which the vehicle 1 is traveling such as a general road or a highway, the brightness (time zone) around which the vehicle 1 is traveling, such as daytime or nighttime, The weather etc. are mentioned.

  The travel control device 10 includes means for detecting the surrounding environment in which the vehicle 1 is traveling. For example, the travel control device 10 can detect whether the vehicle 1 is traveling on a general road or a highway from GPS and map data. Moreover, the traveling control apparatus 10 can detect whether the vehicle 1 is traveling at night from the current time.

  The reliability calculation unit 40 calculates the reliability using different weights according to the detected surrounding environment. That is, even if the factors are the same, the weights given are different if the surrounding environment is different. Tables 1 to 3 illustrate factors and weights for each surrounding environment.

  Table 1 shows factors and weights used when traveling on a general road. When the preceding vehicle (and the vehicle 1 that follows this) travels on a general road, it is considered that the frequency of repeating the stop and transmission with a signal or the like is high, and the driver's characteristics are strongly expressed in acceleration / deceleration. In addition, since ordinary roads have many curves, regardless of whether they can be trusted, it is considered that there will be more or less lateral movement. Therefore, the weight given to the factor when the preceding vehicle is traveling on a general road is set such that the factor relating to acceleration / deceleration is relatively heavier than the factor relating to lateral movement.

  Table 2 shows the factors and weights used when driving on the highway. When the preceding vehicle is traveling on a highway, there are no signals and there are many straight lines. From this, it can be considered that traveling on a highway has little lateral movement. In other words, the fact that there are many movements in the lateral direction despite the straight line can be regarded as dangerous travel. Therefore, the weight given to the factor when the preceding vehicle is traveling on the highway is set such that the factor relating to the lateral movement is relatively heavier than the factor relating to acceleration / deceleration.

  Table 3 shows the factors and weights used when driving at night. When the preceding vehicle is traveling at night, the preceding vehicle may be asleep while driving. For this reason, the driving characteristic factors are equally weighted. In addition, since the visibility at night is worse than in the daytime, the driver factors related to driving by the elderly are set to be relatively heavier than other factors.

  Factors and weighting settings corresponding to the surrounding environment are stored in the main memory. And the determination part 30 determines whether the driving state of the preceding vehicle detected by the detection means 20 corresponds to each factor. A factor having “◯” in the “determination” column of Tables 1 to 3 indicates that the traveling state is determined to correspond to the factor.

  The example of Table 1 indicates that it is determined that the running state corresponds to two factors, “the wobbling in the horizontal direction” and “the amount of movement in the straight direction is equal to or greater than the threshold”. Each of the two corresponding factors has a weight of “−1”. Therefore, “−2”, which is the sum of these, is the credit rating. The same applies to Tables 2 and 3.

  Further, when the factor satisfies a predetermined condition, the weight may be further increased. Further, a positive value may be used as the weight assigned to the factor. Table 5 illustrates factors and weights.

  Table 4 shows factors and weights used when traveling on a general road. Unlike Table 1, “level” is set in the driving characteristic factors “sway in the lateral direction” and “strong acceleration / deceleration”. This means that if the lateral fluctuation exceeds a predetermined threshold, the weight is multiplied by a weak magnification (2 times). Similarly, when the acceleration / deceleration exceeds a predetermined threshold, it means that a strong magnification (6 times) is multiplied by the weight.

  That is, when the driving state corresponds to the driving characteristic factor “fluctuation in the lateral direction”, the weighting of “−1” may not be applied uniformly, but the processing may be doubled depending on the degree.

  In addition, when the driving state of the preceding vehicle corresponds to “driving by a beginner”, it is 9 months (9 months after attaching the beginner driving sign or 9 months after the driver of the preceding vehicle obtains a license) Can be multiplied by 0.4 times or the like. In other words, since it is a driving by a beginner, the weight “−30” may not be given uniformly, but a process of multiplying the time by 0.4 may be performed.

  For example, the determination of the elapse of 9 months is made using a database that stores the time when the driver obtained the license, the number of the car to be driven, and the like. The traveling control device 10 reads the number written on the license plate of the preceding vehicle and queries the database based on the number to determine whether the preceding vehicle is “driving by a beginner” for nine months. can do.

  Operation | movement of the traveling control apparatus 10 of this embodiment is demonstrated. 4 and 5 are flowcharts for explaining the operation of the travel control device 10. FIG. 4 shows a case in which the reliability is calculated depending on whether the surrounding environment is a general road or a highway, and FIG. 5 shows a case in which the reliability is calculated depending on whether the surrounding environment is daytime or nighttime.

  As shown in FIG. 4, the traveling control device 10 first determines whether automatic driving is in progress (step S10). If the driver does not instruct the start of automatic driving (step S10: No), the subsequent processing is not performed (END). If the driver has instructed the start of automatic driving (step S10: Yes), it is determined whether the surrounding environment is a general road or a highway (step S11).

  If the surrounding environment is a general road (step S11: Yes), the reliability of the preceding vehicle is calculated using the factors set for the general road and weighting (see Table 1) (step S12). If the surrounding environment is a highway (step S11: No), the reliability of the preceding vehicle is calculated using the factors set for the highway and weighting (see Table 2) (step S13).

  As described in the first embodiment, the credit level is detected by the detection unit 20 by detecting the driving state of the preceding vehicle, the determination unit 30 determines whether the driving state corresponds to each of a plurality of factors, and the credit level calculation unit 40 Obtained by weighting and summing the relevant factors.

Then, the traveling control device 10 switches to the traveling mode corresponding to the reliability and performs automatic driving (cruise control) with the parameters (inter-vehicle distance) set in the traveling mode (step S14). Table 5 shows the inter-vehicle distance for each credit rating.

  There are three types of inter-vehicle distances: “far”, “medium”, and “near” (specific distances are set as numerical values). If the credit rating (S) is positive, normal cruise control is performed. If the reliability is negative, the inter-vehicle distance is set according to the degree. When 0 ≧ credit (S)> − 20, all the inter-vehicle distances can be set (any of “far”, “medium”, and “near” is possible). When −20 ≧ credit (S)> − 50, all settings are possible, but “middle” and “far” are recommended. When −50 ≧ credit rating (S), “near” is prohibited.

  The automatic travel control unit 50 selects either “far”, “medium”, or “near” corresponding to the reliability as the inter-vehicle distance, and performs cruise control.

  With reference to FIG. 5, the operation in the case of calculating the reliability based on whether it is daytime or nighttime will be described. First, the traveling control device 10 determines whether automatic driving is in progress (step S20). If the driver does not instruct the start of automatic driving (step S20: No), the subsequent processing is not performed (END). If the driver has instructed the start of automatic driving (step S20: Yes), it is determined whether the surrounding environment is a general road or a highway (step S21).

  If the surrounding environment is daytime (step S21: Yes), the reliability of the preceding vehicle is calculated using the factors and weights set for daytime (step S22). If the surrounding environment is nighttime (step S21: No), the reliability of the preceding vehicle is calculated using the factors and weights set for nighttime (see Table 3) (step S23).

  As described in the first embodiment, the credit level is detected by the detection unit 20 by detecting the driving state of the preceding vehicle, the determination unit 30 determines whether the driving state corresponds to each of a plurality of factors, and the credit level calculation unit 40 Obtained by weighting and summing the relevant factors.

  Then, the traveling control device 10 switches to the traveling mode corresponding to the reliability and performs automatic driving (cruise control) with the parameter (inter-vehicle distance) set in the traveling mode (step S24). Thereafter, like the operation described with reference to FIG. 4, cruise control is performed so as to take the inter-vehicle distance corresponding to the reliability.

  As described above, the travel control apparatus 10 according to the present embodiment performs automatic travel control by switching the travel mode based on the reliability calculated using different weights depending on the surrounding environment. Factors that should be evaluated as dangerous mainly depend on the surrounding environment. The traveling control apparatus 10 sets a relatively heavy weight to a factor that should be evaluated as dangerous depending on the surrounding environment, and calculates the reliability. Therefore, the reliability calculated in this way is more appropriate for the surrounding environment. And since follow-up driving | running | working is based on this reliability, the safety | security of an automatic driving | operation can be improved further. In addition, the preceding vehicle with low reliability is followed with a sufficient distance between the vehicles, so it is possible to prevent occupants from feeling uneasy or dissatisfied.

  In addition, when the surrounding environment is a general road, the travel control device 10 according to the present embodiment increases factors related to acceleration / deceleration of the preceding vehicle. As a result, it is possible to accurately determine that the preceding vehicle that travels suddenly in acceleration and deceleration that is considered dangerous on a general road has low reliability.

  In addition, when the surrounding environment is a highway, the travel control device 10 according to the present embodiment increases the factors related to the lateral movement of the preceding vehicle. Accordingly, it is possible to accurately determine that the preceding vehicle that travels in the lateral direction, which is considered dangerous on the highway, or travels in the lateral direction has low reliability.

  Further, the travel control device 10 according to the present embodiment increases factors related to the driver of the preceding vehicle when the surrounding environment is nighttime. As a result, it is possible to accurately determine that the preceding vehicle driven by the driver considered to be dangerous at night has low reliability.

<Embodiment 3>
The travel control device 10 according to the first and second embodiments realizes cruise control that travels following the preceding vehicle. However, the present invention is not limited to this, and can also be applied to a fully automatic operation. In fully automatic driving, control is performed to change lanes in addition to following the preceding vehicle.

  The traveling control device 10 may calculate the creditworthiness of the preceding vehicle, and when the creditworthiness is equal to or less than a predetermined threshold, the lane change may be made to pass the preceding vehicle. According to this, since the vehicle does not continue to follow the preceding vehicle having a low reliability, the safety of the automatic driving can be further improved. In addition, it is possible to prevent anxiety and dissatisfaction of passengers by following such a preceding vehicle.

<Other embodiments>
As mentioned above, although one embodiment of the present invention has been described, of course, the present invention is not limited to the above-described embodiment, and addition, omission, replacement, etc., of a configuration is possible without departing from the spirit of the present invention. And other changes are possible.

  For example, the travel control device may include a warning unit that issues a warning to the driver of the vehicle 1 when the reliability is equal to or less than a predetermined threshold. Examples of the warning means include a configuration that displays that the preceding vehicle cannot be trusted on a display provided on the vehicle 1 and a configuration that outputs that the preceding vehicle cannot be trusted by voice to a speaker provided on the vehicle 1. Such warning means can warn the driver that the preceding vehicle cannot be trusted.

  In the second embodiment, different factors and weights are used for the surrounding environment when the road is a general road or a highway and when the road is at night, but the present invention is not limited to this. For example, factors and weights may be set for a complex surrounding environment, such as using factors and weights when the road is a general road and at night.

  Moreover, the specific value of the weight given to a factor is an illustration, and is not limited to the numerical value described in this specification.

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 10 ... Traveling control apparatus, 20 ... Detection means, 21 ... Front radar, 22 ... Camera, 23 ... Image analysis part, 30 ... Determination part, 40 ... Reliability calculation part, 50 ... Automatic travel control part

Claims (11)

Detecting means for detecting a traveling state of a preceding vehicle traveling in front of the vehicle;
A determination unit that determines whether the driving state of the preceding vehicle corresponds to each of a plurality of factors that reduce the reliability of the preceding vehicle;
A weighting unit that performs weighting based on the running state for each corresponding factor, and calculates a creditworthiness by summing the weighting for each factor; and
An automatic travel control unit that causes the vehicle to travel in different travel modes according to the reliability. In the travel control device according to claim 1,
The factor is that the preceding vehicle moves laterally beyond a threshold value, or the preceding vehicle accelerates or decelerates beyond a threshold value. In the traveling control device according to claim 1 or 2,
The travel control device according to claim 1, wherein the factor is that an image obtained by imaging an appearance of the preceding vehicle conforms to a predetermined image pattern. In the traveling control device according to any one of claims 1 to 3,
The reliability control unit increases the weight of the factor as the frequency at which the factor is determined to be applicable by the determination unit increases. In the traveling control device according to any one of claims 1 to 4,
The reliability control unit calculates the reliability using different weights depending on the surrounding environment in which the vehicle is traveling. In the traveling control device according to claim 5,
When the preceding vehicle is traveling on a general road as the surrounding environment,
The travel control device characterized in that a weight given to a factor that accelerates or decelerates the preceding vehicle exceeding a threshold value is made heavier than a weight given to a factor that the preceding vehicle moves laterally beyond the threshold value. In the traveling control device according to claim 5 or 6,
When the preceding vehicle is traveling on a highway as the surrounding environment,
A travel control device characterized in that a weight given to a factor that the preceding vehicle moves laterally beyond a threshold value is made heavier than a weight given to a factor that the preceding vehicle exceeds a threshold value and accelerates or decelerates. In the travel control device according to any one of claims 5 to 7,
When the preceding vehicle is traveling at night as the surrounding environment,
A travel control device characterized in that a weight given to a factor related to a driver of the preceding vehicle is made heavier than a weight given to another factor. In the travel control device according to any one of claims 1 to 8,
The automatic travel control unit controls the vehicle such that the lower the reliability, the wider the inter-vehicle distance with respect to the preceding vehicle. In the traveling control device according to any one of claims 1 to 9,
The automatic travel control unit controls the vehicle to change the lane and overtake the preceding vehicle when the reliability is equal to or lower than a predetermined threshold value. In the travel control device according to any one of claims 1 to 10,
A travel control device comprising: warning means for issuing a warning to a driver of the vehicle when the reliability is equal to or less than a predetermined threshold value.

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