JP2011214989A - Driving support device, driving support method, and driving support program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving support device, method, and program, predicting the remaining amount of groove of a tire while taking into account of a road shape and performing the guidance in accordance with the predicted remaining amount.SOLUTION: The driving support device 10 is equipped with: a map information DB 12a; a travel route search unit 11a; a change amount cost table 12b storing change amount costs of a tire when a vehicle travels along a road for each road shape; a current remaining amount specifying unit 11b specifying the current remaining amount of the groove of the tire; a change amount cost calculation unit 11c calculating change amount costs of the tire on the basis of the change amount costs for each road shape; a predicted remaining amount calculation unit 11d calculating a predicted remaining amount of the groove of the tire on the basis of the current remaining amount and the change amount costs; and a guide control unit 11e performing the guidance about the tire on the basis of the predicted remaining amount.

Description

  The present invention relates to a driving support device, a driving support method, and a driving support program.

  2. Description of the Related Art Conventionally, a vehicle driving support system that notifies a driver about a decrease in tire air pressure in order to prevent a decrease in vehicle controllability or tire puncture due to a decrease in vehicle tire air pressure. Proposed. As such a vehicle travel support system, for example, when the tire air pressure detected by the tire air pressure detection sensor is low, the tire air pressure is set before reaching the expressway on the planned travel route searched by the navigation system. There is one that performs notification of replenishment (see, for example, Patent Document 1).

JP 2005-119533 A

  Incidentally, a groove for preventing the vehicle from slipping by draining water between the tire and the road surface is provided on the circumferential surface of the tire. In order to properly exhibit the drainage performance of this groove, it is necessary that a groove having a depth of a certain level or more remains. Accordingly, when the depth of the groove becomes less than a constant due to wear of the tire due to use, it is necessary to replace the tire.

  However, in the conventional system such as Patent Document 1, guidance based on the tire pressure is merely performed, and no consideration is given to the wear of the tire groove. If the groove was worn, no guidance could be provided. In particular, the wear amount of the tire groove is considered to vary depending not only on the travel amount of the vehicle but also on the road shape on which the vehicle travels. Was not considered at all.

  The present invention has been made in view of the above, and it is possible to predict the remaining amount of the tire groove in consideration of the road shape, and to perform driving according to the predicted remaining amount. An object is to provide a device, a driving support method, and a driving support program.

  In order to solve the above-described problems and achieve the object, the driving support device according to claim 1 includes a map information storage unit that stores map information, and a travel route search that searches for a travel route from the current location to the destination. Means, a change amount cost storage means for storing the change amount cost of the tire when the vehicle travels on the road for each road shape, and a current remaining amount specifying means for specifying the current remaining amount of the groove of the tire of the vehicle; Based on the travel route searched by the travel route search means and the map information stored by the map information storage means, a road shape to a predetermined point on the travel route is specified, and the specified road A change amount for calculating a tire change amount cost when the vehicle travels to a predetermined point on the travel route based on the shape and the change amount cost for each road shape stored in the change amount cost storage means The vehicle up to a predetermined point on the travel route based on the current calculation amount calculated by the strike calculation unit, the current remaining amount specified by the current remaining amount determination unit, and the variation cost calculated by the variation cost calculation unit Prediction remaining amount calculating means for calculating the predicted remaining amount of the groove of the tire, and guidance means for performing guidance related to the tire of the vehicle based on the predicted remaining amount calculated by the predicted remaining amount calculating means.

  Further, the driving support device according to claim 2 is the driving support device according to claim 1, wherein the change amount cost storage unit stores the change amount cost for each tire, and the current remaining amount specifying unit includes The current remaining amount is specified for each tire, the variation cost calculating unit calculates the variation amount cost for each tire, and the predicted remaining amount calculating unit calculates the predicted remaining amount for each tire, The guiding means performs guidance for each tire based on the predicted remaining amount for each tire calculated by the predicted remaining amount calculating means.

  The driving support device according to claim 3 is the driving support device according to claim 1 or 2, wherein the map information storage means stores map information including information for identifying a road type, and the amount of change The cost storage means stores the change amount cost for each road type, and the change amount cost calculation means is stored in the travel route searched by the travel route search means and the map information storage means. Based on the map information, the road shape and road type up to a predetermined point in the travel route are specified, the specified road shape and road type, and each road shape and road stored in the variation cost storage means Based on the variation cost for each type, the tire variation cost when the vehicle travels to a predetermined point on the travel route is calculated.

  In addition, the driving support device according to claim 4 is the driving support device according to any one of claims 1 to 3, wherein the driving pattern acquisition means for acquiring the driving pattern of the vehicle and the change amount cost storage. Travel pattern correction means for correcting the variation cost stored in the means based on the travel pattern acquired by the travel pattern acquisition means.

  The driving support apparatus according to claim 5 is the driving support apparatus according to claim 4, wherein the driving pattern history information storage means stores the driving pattern acquired by the driving pattern acquisition means as driving pattern history information. The travel pattern correction means corrects the change amount cost stored in the change amount cost storage means based on the travel pattern history information stored in the travel pattern history information storage means.

  Further, the driving support device according to claim 6 is the driving support device according to any one of claims 1 to 5, wherein the driving condition is acquired when the vehicle travels on the travel route. And travel condition correction means for correcting the variation cost based on the travel condition of the vehicle acquired by the travel condition acquisition means.

  The driving support method according to claim 7 includes a travel route search step for searching a travel route from a current location to a destination, a current remaining amount specification step for specifying a current remaining amount of a groove of a vehicle tire, Based on the travel route searched in the travel route search step and the map information stored in the map information storage means for storing the map information, the road shape to the predetermined point in the travel route is specified, and the identification The vehicle up to a predetermined point on the travel route based on the road shape and the change cost for each road shape stored in the change cost storage means as the change cost of the tire when the vehicle travels on the road A change amount cost calculating step for calculating a change amount cost of the tire when the vehicle travels, a current remaining amount specified in the current remaining amount specifying step, and the change amount cost calculating step Based on the calculated change amount cost, the estimated remaining amount calculating step for calculating the estimated remaining amount of the groove of the tire of the vehicle at the predetermined point on the travel route and the predicted remaining amount calculating step were calculated. And a guidance step for providing guidance on the tires of the vehicle based on the predicted remaining amount.

  A driving support program according to an eighth aspect causes a computer to execute the method according to the seventh aspect.

  According to the driving support apparatus according to claim 1, the driving support method according to claim 7, or the driving support program according to claim 8, the road shape on the travel route and the change cost table 12 b are stored. Based on the change cost for each road shape, the change cost of the tire when the vehicle travels on the travel route is calculated, and the current remaining amount of the tire groove and the change cost calculation unit 11c Based on the calculated tire change cost, the estimated remaining amount of the tire groove of the vehicle at a predetermined point on the travel route is calculated, and guidance on the tire of the own vehicle is performed based on the estimated remaining amount. The remaining amount of the tire groove can be predicted in consideration of the amount of wear of the tire according to the road shape of the travel route, and the accuracy of guidance regarding the tire can be improved.

  According to the driving support device of claim 2, the change amount cost is stored for each tire, the current remaining amount is specified for each tire, the change amount cost is calculated for each tire, and the predicted remaining amount is calculated for each tire. Since the calculation and the guidance for each tire is performed based on the predicted remaining amount for each tire, the remaining amount of the groove can be predicted for each tire in consideration of the amount of wear that differs depending on the position of the tire, The accuracy can be further increased. For example, when providing guidance for prompting tire replacement, guidance for prompting replacement can be provided for each tire.

  According to the driving support device according to claim 3, the road shape and road type in the travel route are specified, and the specified road shape and road type are stored for each road shape and road stored in the variation cost table 12b. Based on the change cost for each type, the tire change cost when the vehicle travels along the travel route is calculated. The remaining amount can be predicted, and the accuracy of guidance regarding the tire can be further enhanced.

  According to the driving support device of the fourth aspect, since the tire wear amount changes depending on the vehicle running pattern (for example, the deceleration pattern, the vehicle speed, etc.), the variation cost is acquired by the running pattern acquisition unit. Therefore, the remaining amount of tire grooves can be predicted in consideration of different amounts of wear due to differences in the driving pattern of the driver, further improving the accuracy of guidance related to the tire. Can do.

  According to the driving support device of the fifth aspect, since the variation cost is corrected based on the travel pattern history information, the driving pattern of the driver can be specified more accurately, and the variation cost can be appropriately set. It can be corrected.

  According to the driving support device of the sixth aspect, since the variation cost is corrected based on the traveling condition when the vehicle travels on the traveling route, different wear amounts due to the difference in the traveling condition of the vehicle. Therefore, the remaining amount of the tire groove can be predicted, and the accuracy of guidance regarding the tire can be further enhanced.

1 is a block diagram illustrating a driving support system according to a first embodiment. It is the figure which illustrated the information stored in change amount cost table, (a) is the change amount cost table of a highway, (b) is the change amount cost table of a general road. It is a flowchart of a driving assistance process. FIG. 4 is a block diagram illustrating a driving support system according to a second embodiment. It is the figure which illustrated the information stored in driving pattern history DB. It is a flowchart of a driving | running | working pattern acquisition process. It is a flowchart of a correction process.

  Hereinafter, embodiments of a driving support device, a driving support method, and a driving support program according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited by these embodiments.

[Embodiment 1]
First, the first embodiment will be described. In the first embodiment, the predicted remaining amount of the tire groove at a predetermined point on the travel route is based on the current remaining amount of the vehicle tire groove and the tire variation cost calculated by the variation cost calculating means. This is a form to calculate.

(Constitution)
First, the configuration of the driving support system according to Embodiment 1 will be described. FIG. 1 is a block diagram illustrating a driving support system according to the first embodiment. As shown in FIG. 1, the driving support system 1 includes a driving support device 10, a vehicle speed sensor 20, a current position detection processing unit 30, an air pressure sensor 40, a communication unit 50, a speaker 60, and a display 70. .

(Configuration-vehicle speed sensor)
The vehicle speed sensor 20 outputs a vehicle speed pulse signal or the like proportional to the rotational speed of the axle to the driving support device 10, and a known vehicle speed sensor can be used.

(Configuration-Current position detection processing unit)
The current position detection processing unit 30 is a current position detection unit that detects a current position of a vehicle (hereinafter, the host vehicle) to which the driving support device 10 is attached. Specifically, the current position detection processing unit 30 includes at least one of a GPS, a geomagnetic sensor, a distance sensor, and a gyro sensor (all of which are not shown), and the current position (coordinates) and direction of the host vehicle. Is detected by a known method.

(Configuration-Air pressure sensor)
The air pressure sensor 40 is for detecting the air pressure of a tire (not shown) of the host vehicle, and is provided for each tire. A known pressure sensor can be used as the air pressure detection sensor.

(Configuration-Communication Department)
The communication unit 50 is a communication unit that receives information transmitted from another vehicle, a control center, or the like, and a known wireless communication device can be used.

(Configuration-Speaker)
The speaker 60 is an output unit that outputs various sounds based on the control of the driving support device 10. The specific form of the sound output from the speaker 60 is arbitrary, and it is possible to output a synthesized sound generated as necessary and a sound recorded in advance.

(Configuration-Display)
The display 70 is a display unit that displays various images based on the control of the driving support device 10. The specific configuration of the display 70 is arbitrary, and a known flat panel display such as a liquid crystal display or an organic EL display can be used.

(Configuration-Driving support device)
The driving support device 10 is driving support means for performing output control of guidance related to tires of the host vehicle, and includes a control unit 11 and a data recording unit 12.

(Configuration-Driving support device-Control unit)
The control unit 11 is a control unit that controls the driving support device 10. Specifically, the CPU 11 is a CPU, various programs that are interpreted and executed on the CPU (a basic control program such as an OS, and an OS that is activated and specified on the OS. And an internal memory such as a RAM for storing the program and various data. In particular, the driving support program according to Embodiment 1 is substantially installed in the driving support device 10 via an arbitrary recording medium or network, thereby substantially configuring each unit of the control unit 11.

  The control unit 11 includes a travel route search unit 11a, a current remaining amount specifying unit 11b, a change amount cost calculating unit 11c, a predicted remaining amount calculating unit 11d, and a guidance control unit 11e in terms of functional concept. The travel route search unit 11a is a travel route search unit that searches for a travel route from the current location to the destination. The current remaining amount specifying unit 11b is a current remaining amount specifying unit that specifies the current remaining amount of the tire groove of the host vehicle. The change amount cost calculation unit 11c is change amount cost calculation means for calculating a change amount cost of the tire when the host vehicle travels on the travel route. The predicted remaining amount calculating unit 11d is a predicted remaining amount calculating unit that calculates the predicted remaining amount of the tire groove of the host vehicle at a predetermined point on the travel route. The guidance control unit 11e is guidance means for performing guidance related to the tires of the host vehicle via the speaker 60 and the display 70. Details of processing executed by each component of the control unit 11 will be described later.

(Configuration-Driving support device-Data recording unit)
The data recording unit 12 is a recording unit that records a program and various data necessary for the operation of the driving support device 10, and is configured using, for example, a hard disk (not shown) as an external recording device. However, any other recording medium including a magnetic recording medium such as a magnetic disk or an optical recording medium such as a DVD or a Blu-ray disk can be used instead of or together with the hard disk.

  The data recording unit 12 includes a map information database (hereinafter referred to as “DB”) 12a and a change cost table 12b. The map information DB 12a is map information storage means for storing map information. “Map information” includes, for example, link data (link number, connection node number, road coordinates, road type, number of lanes, travel restrictions, etc.), node data (node number, coordinates), feature data (signals, road signs, guardrails) , Buildings, etc.), terrain data (road shape, road gradient, road friction coefficient, etc.), map display data for displaying a map on the display 70, and the like.

  The change amount cost table 12b is change amount cost storage means for storing, for each road shape, a tire change amount cost when the host vehicle travels on a road. FIG. 2 is a diagram illustrating information stored in the change cost table 12b. FIG. 2A is a change cost table 12b for a highway, and FIG. 2B is a change cost table 12b for a general road. As illustrated in FIG. 2, information corresponding to the item “road shape” and the item “tire” is stored in the variation cost table 12b, and the variation cost is stored in association with these pieces of information.

  The information stored corresponding to the item “road shape” is information indicating the road shape. For example, in FIG. 2, “straight line”, “right curve”, and “left curve” are stored. ”And“ left curve ”, information indicating the range of the curvature radius of the curve (hereinafter referred to as“ R ”as necessary) (for example,“ 700 m ≧ R ”in FIG. 2A), FIG. In the example, “200 m ≧ R” is stored. The information stored corresponding to the item “tire” is information indicating the position of the tire in the host vehicle. For example, in FIG. 2, “left rear”, “right rear”, “left front”, and “right front” are stored. Has been. The amount of change cost is stored in association with information corresponding to these items “road shape” and “tire”. For example, in the change amount cost table 12b shown in FIG. 2A, the wear amount of the tire when traveling 1 km on the highway is stored as the change amount cost. In addition, in the change amount cost table 12b shown in FIG. 2B, the amount of wear of the tire when the vehicle travels 1 km on a general road is stored as the change amount cost.

  When the host vehicle travels on a straight road, the tire is worn mainly due to friction in the traveling direction of the host vehicle between the tire and the road surface during acceleration / deceleration. On the other hand, when the host vehicle runs on a curve, friction in a direction orthogonal to the traveling direction of the host vehicle is applied by the centrifugal force acting on the host vehicle, so that the amount of tire wear increases compared to when the host vehicle runs on a straight line. To do. Therefore, the change amount cost table 12b illustrated in FIG. 2 is configured such that the change amount cost is larger when the road shape is a curve than when the road shape is a straight line (however, for some change cost, a straight line and a curve are used. And the same). Also, the smaller the curvature radius of the curve, the greater the centrifugal force acting on the vehicle, and the greater the frictional force generated. Therefore, the curve with the smaller curvature radius has a higher change amount cost.

(processing)
Next, driving support processing executed by the driving support device 10 configured as described above will be described. FIG. 3 is a flowchart of the driving support process (steps are abbreviated as “S” in the description of each process below). This driving support process is activated, for example, when the driver gives an instruction to search for a travel route via a known input means (not shown).

  First, the travel route searching unit 11a uses a current position of the host vehicle acquired by the current position detection processing unit 30 as a departure point, and knows a travel route from the departure point to a destination set by the driver. The route search method is used (SA1).

  Next, the variation cost calculation unit 11c identifies the road shape and road type of the travel route based on the travel route searched by the travel route search unit 11a and the map information stored in the map information DB 12a. (SA2). For example, the change amount cost calculation unit 11c calculates the road type (for example, an expressway or a general road) corresponding to each link constituting the travel route, and the road shape (for example, a straight line, a curve, or a curvature radius in the case of a curve). Are specified based on link data, terrain data, and the like stored in the map information DB 12a.

  Subsequently, the current remaining amount specifying unit 11b specifies the current remaining amount of the tire groove of the host vehicle for each tire (SA3). For example, the current remaining amount specifying unit 11b periodically calculates the remaining amount of the tire groove while the host vehicle is traveling, records the remaining amount in the data recording unit 12, and uses the last recorded remaining amount as the current remaining amount. Identify. The tire groove remaining amount calculation method is arbitrary. For example, when the tire air pressure detected via the air pressure sensor 40 is within a specified range, the travel distance of the vehicle at a predetermined time is specified using GPS. At the same time, the number of rotations of the tire at that time is specified using a known wheel speed sensor. The circumference of the tire is calculated by dividing the travel distance by the number of rotations of the tire, and the diameter of the tire is calculated from the circumference. By subtracting the difference between the tire diameter calculated in this way and the tire diameter when not in use from the groove depth of the tire when not in use, the remaining amount of the groove can be calculated.

  Next, the change amount cost calculation unit 11c calculates the travel route based on the road shape and road type specified in SA2 and the change amount cost for each road shape and each road type stored in the change amount cost table 12b. Is calculated for each tire (SA4). For example, the change cost calculation unit 11c refers to the change cost table 12b corresponding to the road type of the link for each link constituting the travel route, and specifies the change cost corresponding to the road shape of the link. For example, when the road type of a link is a highway and the road shape of the link is a right curve with a curvature radius of 650 m, according to the change cost table 12b of FIG. The change amount cost of the left rear, right rear, and right front tires is specified to be “0.2 μm”, and the left front tire is “0.3 μm”. If the road type of a link is a general road and the road shape of the link is a left curve with a radius of curvature of 250 m, the link is 1 km according to the variation cost table 12b in FIG. The amount of change cost for each tire when traveling is specified to be “0.4 μm” for the left rear, right rear, and left front tires and “0.5 μm” for the right front tire. Therefore, when the length of the link is 2 km, for example, the change amount cost for each tire in the link is “0.8 μm” for the left rear, right rear and left front tires and “1.0 μm” for the right front tire. It is specified.

  Returning to FIG. 3, the predicted remaining amount calculating unit 11 d is calculated for each tire by the current remaining amount specifying unit 11 b for each tire in SA 3 and for each tire by the variation cost calculating unit 11 c in SA 4. Based on the change amount cost, the predicted remaining amount of the tire groove of the host vehicle at a predetermined point on the travel route is calculated for each tire (SA5). Here, the “predetermined point” is an arbitrary point on the travel route, and for example, a destination or a waypoint can be used. For example, in the first embodiment, the predicted remaining amount calculating unit 11d adds the amount of change cost calculated in SA4 for each link constituting the travel route from the current position to the destination, thereby calculating the destination from the current position. Calculate the cost of change up to Then, the estimated remaining amount of the tire groove of the host vehicle at the destination is calculated by subtracting the calculated change amount cost from the current remaining amount.

  Next, the guidance control unit 11e determines whether there is a tire for which the predicted remaining amount calculated by the predicted remaining amount calculating unit 11d is less than a specified value (SA6). The specific value of this specified value is arbitrary, and for example, a value obtained by adding a certain margin to the depth (for example, 1.6 mm) of the groove where the slip sign of the tire appears is used as the specified value.

  As a result, when there is a tire that is less than the specified value (SA6, Yes), the guidance control unit 11e provides guidance regarding the tire via the speaker 60 and the display 70 (SA7). The specific content of the guidance is arbitrary. For example, the estimated remaining groove of the tire on the travel route is less than a specified value, or the position of the tire where the estimated remaining groove of the groove is less than the specified value (left rear, right rear , Left front, right front), the point where the predicted remaining amount of the tire groove is less than the prescribed value, etc. are guided. Further, the current remaining amount or the predicted remaining amount of the tire in which the predicted remaining amount of the groove does not become less than the specified value may be guided together. This completes the driving support process. On the other hand, if there is no tire that is less than the specified value (SA6, No), it is not necessary to provide guidance regarding the tire, and the driving support process is terminated.

(effect)
As described above, according to the first embodiment, based on the road shape in the travel route and the change amount cost for each road shape stored in the change amount cost table 12b, the host vehicle reaches the predetermined point on the travel route. The tire variation cost when traveling is calculated, and based on the current remaining amount of the tire groove and the tire variation cost calculated by the variation cost calculation unit 11c, Since the estimated remaining amount of the tire groove of the vehicle is calculated and guidance on the tire of the host vehicle is performed based on this estimated remaining amount, the amount of tire groove is considered in consideration of the amount of tire wear according to the road shape of the travel route. The remaining amount can be predicted, and the accuracy of guidance related to the tire can be increased.

  Also, the change cost is stored for each tire, the current remaining amount is specified for each tire, the change cost is calculated for each tire, the predicted remaining amount is calculated for each tire, and based on the predicted remaining amount for each tire. Since the guidance for each tire is performed, the remaining amount of the groove can be predicted for each tire in consideration of the amount of wear that varies depending on the position of the tire, and the accuracy of guidance regarding the tire can be further improved. For example, when providing guidance for prompting tire replacement, guidance for prompting replacement can be provided for each tire.

  Further, the road shape and road type in the travel route are identified, and based on the identified road shape and road type, and the change cost for each road shape and each road type stored in the change cost table 12b, Since the change cost of the tire when the host vehicle travels along the travel route is calculated, the remaining amount of the tire groove can be predicted in consideration of the wear amount of the tire depending on the road type. The accuracy of guidance can be further increased.

[Embodiment 2]
Next, a second embodiment will be described. In the second embodiment, the variation cost stored in the variation cost storage means is corrected based on a traveling pattern when the host vehicle travels a curve. The configuration of the second embodiment is substantially the same as the configuration of the first embodiment, unless otherwise specified. The same configuration as that of the first embodiment is used in the first embodiment. The same reference numerals and / or names as those used are attached as necessary, and description thereof is omitted.

(Configuration-Driving support device-Control unit)
First, the configuration of the driving support system according to the second embodiment will be described. FIG. 4 is a block diagram illustrating a driving support system according to the second embodiment. As shown in FIG. 4, the control unit 11 of the driving assistance apparatus 10 according to the second embodiment includes a travel pattern acquisition unit 11 f and a travel pattern correction unit 11 g in addition to the same configuration as that of the first embodiment. .

  The travel pattern acquisition unit 11f is a travel pattern acquisition unit that acquires a travel pattern of the host vehicle. Here, as the “travel pattern of the host vehicle”, for example, a deceleration pattern associated with a road shape such as a straight line or a curve, an average vehicle speed of the host vehicle, and the like are acquired. In the second embodiment, a case where the traveling pattern acquisition unit 11f acquires a deceleration pattern when the host vehicle travels a curve will be described as an example. Here, the deceleration pattern when the host vehicle travels on a curve includes, for example, the approach speed to the curve, the presence or absence of deceleration before the curve, and the like. The travel pattern correction unit 11g is a travel pattern correction unit that corrects the variation cost stored in the variation cost table 12b based on the travel pattern acquired by the travel pattern acquisition unit 11f. Details of processing executed by each component of the control unit 11 will be described later.

(Configuration-Driving support device-Data recording unit)
The data recording unit 12 according to the second embodiment includes a travel pattern history DB 12c in addition to the same configuration as the data recording unit 12 according to the first embodiment. The travel pattern history DB 12c is a travel pattern history information storage unit that stores the travel pattern acquired by the travel pattern acquisition unit 11f as travel pattern history information. FIG. 5 is a diagram illustrating information stored in the travel pattern history DB 12c. As shown in FIG. 5, information corresponding to the items “deceleration pattern” and “number of times” is stored in the traveling pattern history DB 12 c in association with each other. The information stored corresponding to the item “deceleration pattern” is information indicating the deceleration pattern of the host vehicle, and information corresponding to the small items “curve entry speed” and “presence / absence of deceleration” is stored. Among these, the information stored corresponding to the item “curve entry speed” is information indicating the range of the vehicle speed when entering the curve. In FIG. 5, “above threshold value” and “below threshold value” are stored. ing. In addition, the information stored corresponding to the item “presence / absence of deceleration” is whether or not the host vehicle has decelerated within a predetermined range before entering the curve when the approach speed to the curve is less than the threshold. In FIG. 5, “present” and “not present” are stored. The information stored corresponding to the item “number of times” is information indicating the number of times the vehicle has traveled the curve with each deceleration pattern. In the example of FIG. 5, when the approach speed to the curve is equal to or higher than the threshold value, 12 times, and when the own vehicle decelerates within the predetermined range before the curve speed is less than the threshold value and before entering the curve, 45 times. There are nine cases where the speed of approaching the curve is less than the threshold and the host vehicle is not decelerating within a predetermined range before entering the curve. As the threshold value, it is preferable to set the minimum value of the approach speed of the curve that changes the wear amount of the tire groove. However, since such a value may differ depending on the curvature radius of the curve, it is preferable to set a threshold according to the curvature radius. A specific example of this threshold will be described later.

(processing)
Next, processing executed by the driving support device 10 configured as described above will be described. The driving assistance apparatus 10 according to the second embodiment executes a deceleration pattern acquisition process and a correction process in addition to the driving assistance process similar to that of the first embodiment. These processes will be described below.

(Processing-deceleration pattern acquisition processing)
First, the deceleration pattern acquisition process will be described. FIG. 6 is a flowchart of the deceleration pattern acquisition process. This deceleration pattern acquisition process is repeatedly started at a predetermined cycle after the start of traveling of the host vehicle, for example.

  First, the traveling pattern acquisition unit 11f determines whether or not the host vehicle has reached a predetermined range before the curve traveling direction (SB1). Specifically, the traveling pattern acquisition unit 11f makes a determination based on the current position of the host vehicle detected via the current position detection processing unit 30 and the map information stored in the map information DB 12a.

  As a result, if the host vehicle does not reach the predetermined range before the curve traveling direction (SB1, No), it is not necessary to acquire the deceleration pattern, and the traveling pattern acquisition unit 11f ends the deceleration pattern acquisition process. To do.

  On the other hand, when the host vehicle reaches a predetermined range before the curve traveling direction (SB1, Yes), the traveling pattern acquisition unit 11f specifies the threshold value of the approach speed in the curve (SB2). The method for specifying the threshold value of the approach speed is arbitrary. For example, a table in which the curvature radius of the curve and the threshold value of the approach speed are associated with each other is stored in the data recording unit 12 in advance. Then, the traveling pattern acquisition unit 11f specifies the curvature radius of the curve on which the host vehicle enters based on the map information stored in the map information DB 12a, and acquires the threshold corresponding to the curvature radius from the table.

  Thereafter, the traveling pattern acquisition unit 11f specifies the presence or absence of deceleration before the curve (SB3). The method for specifying the presence / absence of deceleration is arbitrary. For example, the presence / absence of deceleration is specified based on the presence / absence and operation amount of a brake pedal detected via a known brake sensor (not shown).

  Next, the traveling pattern acquisition unit 11f specifies the approach speed of the host vehicle to the curve based on the input from the vehicle speed sensor 20 (SB4).

  The travel pattern acquisition unit 11f updates the content of the travel pattern history DB 12c based on the threshold value of the approach speed specified in SB2, the presence or absence of deceleration specified in SB3, and the approach speed specified in SB4 (SB5). For example, when the threshold of the approach speed is 40 km / h, the host vehicle is decelerating before the curve, and the approach speed to the curve is 25 km / h, the items in the travel pattern history DB 12c illustrated in FIG. Of the numerical values stored corresponding to “number of times”, the numerical value corresponding to the item “curve approach speed” being “less than threshold” and the item “presence / absence of deceleration” being “none” is added once. This completes the deceleration pattern acquisition process.

(Processing-Correction processing)
Next, the correction process will be described. FIG. 7 is a flowchart of the correction process. This correction process is started after power is supplied to the driving support device 10.

  First, the traveling pattern correction unit 11g determines whether or not a predetermined period has elapsed since the change amount cost table 12b was corrected last time (SC1). The specific value of the predetermined period is arbitrary, and for example, one month is used as a period sufficient to accumulate travel pattern history information.

  As a result, when the predetermined period has not elapsed since the change amount cost table 12b was corrected last time (No in SC1), it is assumed that the change amount cost table 12b should not be corrected, and the control unit 11 performs the correction process. finish.

  On the other hand, when a predetermined period has elapsed since the change amount cost table 12b was corrected last time (SC1, Yes), the travel pattern correction unit 11g acquires travel pattern history information from the travel pattern history DB 12c (SC2). For example, the traveling pattern correction unit 11g refers to the traveling pattern history DB 12c, and acquires the number of times that the host vehicle has traveled a curve with each deceleration pattern.

  Subsequently, the travel pattern correction unit 11g corrects the variation cost stored in the variation cost table 12b based on the travel pattern history information acquired in SC2 (SC3). The variation cost correction method stored in the variation cost table 12b is arbitrary. For example, the correction content of the variation cost corresponding to each deceleration pattern is stored in the data recording unit 12 in advance, and is acquired in SC2. Based on the travel pattern history information, the contents corresponding to the deceleration pattern having the largest number of times are corrected.

  In addition, the amount of change in the cost of change amount is arbitrary. For example, if the deceleration pattern with the largest number of times is a deceleration pattern with “curve entry speed” equal to or greater than “threshold”, the amount of tire wear when traveling on the curve Therefore, as the correction contents corresponding to this deceleration pattern, the “road shape” in the variation cost table 12b in FIG. 2 is changed to all the variation costs corresponding to “right curve” or “left curve”. Add “0.1 μm”. Alternatively, if the deceleration pattern with the highest number of times is a deceleration pattern with “curve approach speed” being “less than threshold” and “presence / absence of deceleration” being “present”, the tire pattern associated with deceleration in the linear region before the curve Since it is considered that the amount of wear is large, the correction content corresponding to this deceleration pattern is “0” for all the variation costs corresponding to “straight line” in the variation cost table 12b in FIG. .1 μm ”is added. Alternatively, when the deceleration pattern with the highest number of times is a deceleration pattern in which the “curve approach speed” is “less than a threshold” and “presence / absence of deceleration” is “none”, Since there is no correction, this deceleration pattern is not particularly corrected. This completes the correction process.

(effect)
As described above, according to the second embodiment, the amount of tire wear varies depending on the travel pattern of the vehicle (for example, the deceleration pattern, the vehicle speed, etc.), and therefore, the variation cost is acquired by the travel pattern acquisition unit 11f. Since the correction is made based on the driving pattern, the remaining amount of the tire groove can be predicted in consideration of the different wear amount due to the difference in the driving pattern of the driver, and the accuracy of guidance related to the tire can be further improved. it can.

  Further, since the variation cost is corrected based on the travel pattern history information, the driving pattern of the driver can be specified more accurately, and the variation cost can be corrected appropriately.

[Modifications to Embodiment]
Although the embodiments of the present invention have been described above, the specific configuration and means of the present invention can be arbitrarily modified and improved within the scope of the technical idea of each invention described in the claims. Can do. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above contents, and may vary depending on the implementation environment and details of the configuration of the invention. May be solved, or only some of the effects described above may be achieved.

(About change amount cost table)
In the first embodiment described above, the change amount cost table 12b shown in FIG. 2A describes that the amount of tire wear when traveling on a highway for 1 km is stored as the change amount cost. The amount of change cost defined by a different standard may be stored. For example, when traveling on an expressway, there is no signal or intersection, so the frequency of acceleration / deceleration of the host vehicle is low, and tire wear due to friction generated by acceleration / deceleration is small. That is, when traveling on a highway, the correlation between the travel distance and the amount of tire wear is low. Therefore, instead of the change amount cost per predetermined travel distance (1 km in the first embodiment), the change amount cost for each link of the expressway in the map information may be stored.

  In addition, although it has been described that the amount of tire wear when the vehicle travels 1 km on a general road is stored in the variation cost table 12b shown in FIG. 2B as the variation cost, there are a plurality of general roads. When classified into road types (for example, urban areas and mountain roads), the change cost may be stored for each of these road types. For example, when traveling on a general road in an urban area, tires wear due to friction generated by the own vehicle accelerating / decelerating at a signal, an intersection, or the like. That is, as the travel distance of a general road in an urban area increases, the number of times of acceleration / deceleration of the host vehicle increases, and the amount of tire wear increases. On the other hand, when traveling on a mountain road, since there are few signals, intersections, etc., the number of times of acceleration / deceleration of the host vehicle is small, and the correlation between the travel distance and the amount of tire wear is low. Therefore, for a general road in an urban area, the change amount cost per predetermined travel distance (for example, 1 km) is stored in the change amount cost table 12b, and for mountain roads, the change amount cost for each link is stored in the change amount cost table 12b. You may make it store.

(About identification of the current remaining amount of the groove)
In the first embodiment described above, when the current remaining amount of the groove of the tire of the host vehicle is specified, the tire diameter is specified based on, for example, the travel distance of the host vehicle and the number of rotations of the tire. Although it has been described that the current remaining amount of the groove is specified based on the above, the current remaining amount of the groove may be specified by another method. For example, the road shape and road type of all roads on which the host vehicle has traveled after the last tire change is specified, and the value obtained by integrating the amount of change cost corresponding to the road shape and road type is used as the tire groove when not in use. The current remaining amount may be calculated by subtracting from the depth.

(About guidance)
In addition, when it is determined in SA6 in FIG. 3 that there is a tire whose predicted remaining amount is less than the specified value (SA6, Yes), the guidance control unit 11e has, for example, the predicted remaining amount of the tire groove on the travel route is less than the specified value. However, in addition to this, other contents may be guided. For example, the amount of change cost when the tire mounting position is changed is calculated for each tire, and the predicted remaining amount at a predetermined point on the travel route is calculated for each tire. As a result, if there is no tire whose predicted remaining amount is less than the specified value, it is possible to drive to the destination without changing the remaining position of the tire groove if the tire mounting position is changed. You may make it guide.

  Further, based on the map information stored in the map information DB 12a, a place where a tire can be exchanged before the point where the predicted remaining amount of the tire groove is less than a specified value (for example, a gas station or a car supply store) ) May be guided.

(Regarding correction of change cost)
In the second embodiment, the variation cost table 12b is corrected based on the traveling pattern of the host vehicle, and the corrected variation cost table 12b is used until the correction is performed again thereafter. Thus, driving support processing is performed. For this reason, the correction can be considered as a steady correction. In addition, as a correction, a temporary correction can be performed. In other words, every time the vehicle travels, it is possible to perform correction according to the travel condition and return to the state before the correction after the travel. Hereinafter, an example of such temporary correction will be described.

  For example, the control unit 11 is based on a traveling condition acquisition unit as a traveling condition acquisition unit that acquires a traveling condition when the vehicle travels on a traveling route, and the traveling condition of the vehicle acquired by the traveling condition acquisition unit. A travel condition correction unit is provided as a travel condition correction means for correcting the change amount cost.

  And a driving condition acquisition part acquires the driving condition at the time of the own vehicle drive | working a driving | running route at the time of the start of a driving assistance process. As the running condition, any running condition that can change the wear amount of the tire groove can be acquired. For example, the number of passengers and the vehicle weight are acquired. As for the number of passengers, for example, a value input by a driver through a known input means can be used. For the vehicle weight, for example, a known weight sensor provided in the vehicle can be used.

  Then, the traveling condition correction unit temporarily corrects the variation cost stored in the variation cost table 12b based on these traveling conditions. For example, when the number of passengers is large (when the vehicle weight is heavy), the amount of tire wear is considered to increase, so the amount of change cost stored in the amount-of-change cost table 12b is uniformly increased by a predetermined amount. Thus, the change amount cost is corrected. In addition, when the road gradient is climbing, it is considered that the wear amount of the rear tire increases, and therefore the change corresponding to the rear tire among the change amount costs stored in the change amount cost table 12b. The amount of change cost is corrected by increasing the amount cost by a predetermined amount. In addition, when the road slope is down, the wear amount of the front tire is considered to increase, and therefore, the change amount cost corresponding to the front tire among the change amount costs stored in the change amount cost table 12b. Is increased by a predetermined amount to correct the change amount cost. Alternatively, the amount of change stored in the amount-of-change cost table 12b is considered that when the number of signals and the number of intersections that need to be paused are large, the amount of tire wear when traveling on a straight line is considered to increase. Among the costs, the change amount cost is corrected by increasing the change amount cost corresponding to the case where the road shape is a straight line by a predetermined amount.

  Thereafter, the variation cost calculation unit 11c calculates the tire variation cost when the host vehicle travels on the travel route based on the variation cost corrected by the travel condition correction unit. In this example, the content of the variation cost table 12b is not corrected. Therefore, when the vehicle travels next time, the travel condition in the next travel is based on the content of the uncorrected variation cost table 12b. Correction according to is performed. In this way, by correcting the amount of change cost based on the traveling conditions when the host vehicle travels along the travel route, the remaining amount of the groove is predicted for each tire in consideration of the amount of wear that varies depending on the traveling conditions of the host vehicle. It is possible to improve the accuracy of guidance related to the tire.

  Note that both the above-described steady correction and temporary correction may be performed. In this case, the amount of wear differs depending on the difference in the driving pattern of the driver, and the driving condition of the host vehicle varies. The remaining amount of the groove can be predicted for each tire in consideration of the amount of wear, and the accuracy of guidance regarding the tire can be further increased.

DESCRIPTION OF SYMBOLS 1 Driving assistance system 10 Driving assistance apparatus 11 Control part 11a Traveling route search part 11b Present remaining amount specific | specification part 11c Change amount cost calculation part 11d Predicted remaining amount calculation part 11e Guidance control part 11f Traveling pattern acquisition part 11g Traveling pattern correction | amendment part 12 Data Recorder 12a Map information DB
12b Change amount cost table 12c Travel pattern history DB
20 Vehicle speed sensor 30 Current position detection processing unit 40 Air pressure sensor 50 Communication unit 60 Speaker 70 Display

Claims (8)

Map information storage means for storing map information;
A travel route search means for searching a travel route from the current location to the destination;
A change cost storage means for storing the change cost of the tire when the vehicle travels on the road for each road shape;
Current remaining amount identifying means for identifying the current remaining amount of the groove of the tire of the vehicle;
Based on the travel route searched by the travel route search means and the map information stored by the map information storage means, a road shape to a predetermined point in the travel route is specified, and the specified road shape And a variation cost for calculating a tire variation cost when the vehicle travels to a predetermined point on the travel route based on the variation cost for each road shape stored in the variation cost storage means. A calculation means;
Prediction of the tire groove of the vehicle at a predetermined point on the travel route based on the current remaining amount specified by the current remaining amount specifying means and the change amount cost calculated by the change amount cost calculating means A predicted remaining amount calculating means for calculating the remaining amount;
Based on the predicted remaining amount calculated by the predicted remaining amount calculating unit, guidance means for performing guidance on the tire of the vehicle;
A driving support apparatus comprising: The change amount cost storage means stores the change amount cost for each tire,
The current remaining amount specifying means specifies the current remaining amount for each tire,
The variation cost calculation means calculates the variation cost for each tire,
The predicted remaining amount calculating means calculates the predicted remaining amount for each tire,
The guiding means performs guidance for each tire based on the predicted remaining amount for each tire calculated by the predicted remaining amount calculating means.
The driving support device according to claim 1. The map information storage means stores map information including information specifying a road type,
The change cost storage means stores the change cost for each road type,
Based on the travel route searched by the travel route search means and the map information stored in the map information storage means, the change amount cost calculation means includes a road shape to a predetermined point on the travel route, and Identify the road type, and based on the identified road shape and road type, and the change cost for each road shape and each road type stored in the change cost storage means, up to a predetermined point on the travel route Calculate the tire change amount cost when the vehicle travels,
The driving support device according to claim 1 or 2. Traveling pattern acquisition means for acquiring a traveling pattern of the vehicle;
Travel pattern correction means for correcting the change amount cost stored in the change amount cost storage means based on the travel pattern acquired by the travel pattern acquisition means;
The driving support device according to any one of claims 1 to 3, further comprising: Travel pattern history information storage means for storing the travel pattern acquired by the travel pattern acquisition means as travel pattern history information;
The travel pattern correction unit corrects the variation cost stored in the variation cost storage unit based on the travel pattern history information stored in the travel pattern history information storage unit.
The driving support device according to claim 4. Travel condition acquisition means for acquiring a travel condition when the vehicle travels along the travel route;
Traveling condition correction means for correcting the change amount cost based on the traveling condition of the vehicle acquired by the traveling condition acquisition means;
The driving support device according to any one of claims 1 to 5, further comprising: A travel route search step for searching a travel route from the current location to the destination;
A current remaining amount identifying step for identifying the current remaining amount of the groove of the vehicle tire,
Based on the travel route searched in the travel route search step and the map information stored in the map information storage means for storing the map information, the road shape to the predetermined point in the travel route is specified, Based on the identified road shape and the change amount cost for each road shape stored in the change amount cost storage means as the change amount cost of the tire when the vehicle travels on the road, to the predetermined point of the travel route A change cost calculating step for calculating a change cost of the tire when the vehicle travels;
Prediction of the tire groove of the vehicle at a predetermined point on the travel route based on the current remaining amount specified in the current remaining amount specifying step and the change amount cost calculated in the change amount cost calculating step A predicted remaining amount calculating step for calculating the remaining amount;
Based on the predicted remaining amount calculated in the predicted remaining amount calculating step, a guidance step for performing guidance related to the tire of the vehicle;
Driving support method including.   The driving assistance program which makes a computer perform the method of Claim 7.

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