JP2006300595A - Navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make arrival time forecasted by a navigation system more accurate. <P>SOLUTION: An environment state detection means 6 for detecting a state of a travel environment for a vehicle is provided on the vehicle. Forecasted destination arrival time is calculated so that it varies according to the state of the travel environment detected by the detection means 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle navigation system.

  A vehicle navigation system generally calculates an expected arrival time based on a route from a current position to a destination and a vehicle speed expected for each road, and displays the estimated arrival time on a display (Patent Document 1). ).

  However, the actual vehicle speed is slower than the expected vehicle speed when the driving environment is bad, such as when the visibility is low due to rain, when the temperature is low and the road surface is frozen, or when driving on a dark night road. Often becomes. For this reason, the difference between the predicted arrival time and the actual arrival time is large, and the reliability of the predicted arrival time is low. Further, the expected arrival time is delayed every time it is updated, and there is a problem that the driver is irritated.

JP-A-9-96539

  An object of the present invention is to make the arrival time predicted by the navigation system more accurate.

  In order to solve the above problems, the vehicle is provided with an environmental state detection means for detecting the state of the traveling environment of the vehicle, and the expected arrival time at the destination according to the state of the traveling environment detected by the environmental state detection means It was made to fluctuate.

  Here, the standard required time is calculated based on the route from the current position to the destination as a configuration in which the expected arrival time at the destination is changed according to the state of the driving environment detected by the environmental state detection means. Standard required time calculating means and expected required time calculating means for calculating the expected required time by varying the standard required time calculated by the standard required time calculating means according to the state of the driving environment detected by the environmental condition detecting means. And a time conversion means for calculating the expected arrival time by adding the expected required time calculated by the expected required time calculating means to the current time.

This navigation system becomes more preferable when the following configuration is added.
1) As the environmental state detection means, a CCD camera that captures the front of the vehicle, and whether the traveling environment of the vehicle is clear or a plurality of weather conditions including rain are determined based on an image captured by the CCD camera. A weather determination means, and when the weather determination means determines that it is raining, the expected required time is made longer than when it is determined to be sunny.
2) A temperature sensor for detecting the temperature of the traveling environment of the vehicle is provided as the environmental state detection means, and when the temperature detected by the temperature sensor is equal to or lower than a preset expected freezing temperature, the detected temperature is the expected freezing temperature. The estimated required time is made longer than when the temperature is exceeded.
3) As the environmental state detection means, a CCD camera that captures the road surface on which the vehicle travels, and a plurality of states including a dry state and a wet state based on an image captured by the CCD camera. Road surface determination means for determining the road surface, and when the road surface determination means determines that the road surface is wet, the estimated required time is made longer than when the road surface is determined to be dry.
4) As the environmental state detection means, a CCD camera or an illuminance sensor that detects the brightness of the driving environment of the vehicle is provided. When the brightness detected by the CCD camera or the illuminance sensor is dark, the detected brightness is bright. The estimated required time is made longer than that.

  Since the state of the traveling environment of the vehicle is reflected in the expected arrival time, the expected arrival time becomes more accurate. Therefore, the driver's impatience is alleviated and accidents due to impatience can be prevented.

  FIG. 1 shows the configuration of the navigation system according to the first embodiment of the present invention. This navigation system includes a destination input device 1 that inputs a destination, a GPS receiver 2 that receives GPS signals, a map information storage device 3 that stores map information, and a control unit 4 that calculates an estimated arrival time. And a display device 5 for displaying the map information and the estimated arrival time. Further, a CCD camera 6 for photographing the front and a vehicle control ECU (electronic control unit) 7 for controlling the vehicle based on the image data of the CCD camera 6 are provided. The image data is transmitted to the control unit 4.

  The GPS receiver 2 is attached to the vehicle as shown in FIG. 2, and receives GPS signals emitted from a plurality of GPS satellites. The received GPS signal is transmitted to the control unit 4.

  The control unit 4 determines the current position of the vehicle based on the time when the GPS receiver 2 receives the GPS signal and the transmission time information and position information of the GPS satellites included in the GPS signal, and a map corresponding to the current position. Information is read from the map information storage device 3. As the map information storage device 3, for example, a hard disk or an external memory card incorporated in the same housing as the control unit 4 can be employed. The map information read from the map information storage device 3 is transmitted to the display device 5, and the current position and the surrounding map are displayed on the display device 5.

  On the other hand, the destination is input to the destination input device 1 by an address, a telephone number, coordinates on a map, or the like. As the destination input device 1, for example, a touch panel, a voice recognition microphone, a remote controller, or the like incorporated in the display device 5 can be adopted.

  As the vehicle control ECU 7, for example, a control ECU for a driving support device that supports steering operation so as to maintain traveling in the lane based on image data of the CCD camera 6, or forward based on image data of the CCD camera 6. There is an ECU for controlling an automatic braking device that operates a brake so as to prevent a collision with an obstacle. Based on the image data of the CCD camera 6 sent from the vehicle control ECU 7 to the control unit 4, the control unit 4 determines whether the weather in the driving environment of the vehicle is clear, rain, snow, or any other condition. To do.

  The control of the navigation system configured as described above will be described with reference to FIG.

First, a destination is input to the destination input device 1 (step S ₁ ). When the destination is input, the control unit 4 searches for a route from the current position to the destination (step S ₂ ). When the route is determined, the control unit 4, based on the standard speed set for each the paths and the road to calculate the average time T ₀ (step S _3), the average time T _0, CCD camera 6 The estimated required time T is calculated based on the weather determined based on the image data (step S ₄ ). The predicted required time T thus calculated is added to the current time to calculate the predicted arrival time (step S ₅ ), and the predicted arrival time is displayed on the display device 5 (step S ₆ ).

Steps S _{3 to} S ₆ are repeated at regular intervals, and the expected arrival time displayed on the display device 5 is updated each time.

Here, the step S ₄ to calculate the predicted travel time T by varying the average time T _0, it will be described in detail with reference to FIG.

First, the standard required time T ₀ is set (step S ₁₁ ). Next, assuming that the vehicle control system is normal (step S ₁₂ ), when the weather is fine, T ₀ is set as the expected required time T (steps S ₁₃ and S ₁₄ ). On the other hand, when the weather is raining, (T ₀ + A) is set as the expected required time T (steps S ₁₅ and S ₁₆ ). When the weather is snowy, (T ₀ + B) is set as the expected required time T (steps S ₁₇ and S ₁₈ ). When the weather is not sunny, rainy or snowy, for example, when it is snowstorm or fog, (T ₀ + C) is set as the estimated required time T (step S ₁₉ ). Here, A, B, and C are correction values that satisfy the relationship of A <B <C. Therefore, the estimated required time T is the shortest when the weather is clear, and the weather is rain, snow, and other orders in that order. It becomes longer gradually.

  When this navigation system is used, when the weather of the vehicle traveling environment becomes rain, snow, snowstorm, or the like, the expected arrival time is delayed compared to when the weather is fine. Therefore, the predicted arrival time displayed on the display device 5 becomes more accurate, and the driver can know the more accurate predicted arrival time.

  In this embodiment, the control unit 4 combines the vehicle control ECU 7 and the CCD camera 6 to realize an efficient device configuration. However, a CCD camera dedicated to the car navigation system may be provided. In addition, other means may be used as means for detecting the weather in the traveling environment as long as the weather in the traveling environment of the vehicle can be detected. For example, a barometer is provided in the vehicle in place of the CCD camera 6, and the barometer The weather may be detected using an atmospheric pressure signal.

  In addition, although the description has been given by taking sunny, rainy, and snow as weather conditions to be detected, the weather may be detected according to other categories such as sunny, cloudy, light rain, heavy rain, light snow, heavy snow, and fog.

  FIG. 5 shows the configuration of the navigation system according to the second embodiment of the present invention. In this navigation system, the CCD camera 6 and the vehicle control ECU 7 of the first embodiment are replaced with an air temperature sensor 8, and the other configuration is the same as that of the first embodiment.

Control of the navigation system, only the steps S ₄ to calculate the predicted travel time T by varying the average time T ₀ is different from the first embodiment. This step S _4, it will be described with reference to FIG.

First, the standard required time T ₀ is set (step S ₂₁ ). Next, when the temperature is 30 ° C. or higher, (T ₀ + D) is set as the expected required time T (steps S ₂₂ and S ₂₃ ). When the temperature is less than 30 degrees and 0 degrees or more, T ₀ is set as the expected required time T (steps S ₂₄ and S ₂₅ ). When the temperature is less than 0 degrees, (T ₀ + E) is set as the expected required time T (step S ₂₆ ). Here, D and E are correction values having a relationship of D <E, and therefore the expected required time T is the shortest when the temperature is 0 ° C. or more and less than 30 ° C., and is the shortest when the temperature is 0 ° C. or less. become longer.

  When this navigation system is used, when the temperature becomes 0 ° C. or less and the road surface is predicted to freeze, the expected arrival time is delayed as compared to when the temperature is normal. Further, even when the temperature becomes 30 ° C. or higher and a decrease in the gripping force of the tire against the road surface is predicted, the expected arrival time is delayed compared to when the temperature is normal temperature. Therefore, as in the first embodiment, the predicted arrival time displayed on the display device 5 becomes more accurate, and the driver can know the more accurate predicted arrival time.

  In this embodiment, the temperature at which the road surface is predicted to freeze is set to 0 degrees, but may be other temperatures, for example, 4 degrees. Further, the temperature classification may be further increased. For example, the predicted arrival time may be different between the temperature of 20 degrees or more and less than 20 degrees.

Next, a navigation system according to a third embodiment of the present invention will be described. This navigation system has the same configuration as that of the first embodiment, but is different in that the state of the driving environment detected based on the image data of the CCD camera 6 is not the weather but the road surface. That is, the control unit 4 determines whether the road surface is dry asphalt, wet asphalt, or any other condition based on the image data of the CCD camera 6. Control of the navigation system, like the second embodiment, only the steps S ₄ to calculate the predicted travel time T by varying the average time T ₀ is different from the first embodiment. This step S _4, it will be described with reference to FIG.

First sets average time _{T 0} (step _S 31). Next, assuming that the vehicle control system is normal (step S ₃₂ ), when the road surface is dry asphalt, T ₀ is set as the expected required time T (steps S ₃₃ and S ₃₄ ). On the other hand, when the road surface is wet asphalt, (T ₀ + F) is set as the expected required time T (steps S ₃₅ and S ₃₆ ). When the road surface is not in any of these states, for example, when the road surface is a gravel road, a snow road, etc., (T ₀ + G) is set as the estimated required time T (step S ₃₇ ). Here, F and G are correction values satisfying the relationship of F <G. Therefore, the estimated required time T is longer when wet asphalt than when dry asphalt, and the road surface is When it is not in any of these states, it becomes longer.

  When this navigation system is used, when the road surface becomes wet asphalt and slip is predicted, the expected arrival time is delayed compared to when the road surface is dry asphalt. Further, when the road surface is not in any of these states, for example, when the road surface is a gravel road or a snow road, the expected arrival time is further delayed. Therefore, the expected arrival time displayed on the display device 5 becomes more accurate, and the driver can know the more accurate predicted arrival time.

  In this embodiment, the road surface state is determined based on the image data of the CCD camera 6, but other means may be used as long as the road surface state can be detected. For example, a moisture system for measuring the road surface state, A thermometer may be provided in the vehicle, and the road surface condition may be detected using the measurement signal. In addition, as an example of the road surface condition, dry asphalt and wet asphalt have been described as examples. However, the expected arrival time may be changed according to the road surface condition, for example, asphalt, gravel road, snow road. It may be possible to detect which state is present and to change the expected arrival time according to the detected state.

Next explained is a navigation system according to the fourth embodiment of the invention. This navigation system has the same configuration as that of the first embodiment, but is different in that the state of the driving environment detected based on the image data of the CCD camera 6 is not the weather but the brightness. That is, the control unit 4 determines whether the brightness is in the daytime state, the nighttime state, or any other state based on the image data of the CCD camera 6. Control of the navigation system is also only steps S ₄ to calculate the predicted travel time T by varying the average time T ₀ is different from the first embodiment. This step S _4, it will be described with reference to FIG.

First, the standard required time T ₀ is set (step S ₄₁ ). Next, (step _{S 42)} assuming that the vehicle control system is normal, when the brightness is the day of the state sets _(T 0 -H) in the expected time T (step _S 43, S ₄₄ ). On the other hand, when the brightness is night, (T ₀ + I) is set as the expected required time T (steps S ₄₄ and S ₄₅ ). When the brightness is not in any of these states, for example, when it is twilight, T ₀ is set as the expected required time T (step S ₄₆ ). Here, H and I are equal correction values. Therefore, the estimated required time T is longer when the brightness is nighttime than when it is daytime, and when the brightness is neither daytime nor nighttime, when the brightness is daytime Longer and shorter than night conditions.

  With this navigation system, when the brightness is at night, the expected arrival time is later than when the brightness is in the daytime, and when the brightness is not in any state of the day or night, for example, at dusk, The expected arrival time is later than that in the daytime and earlier than in the nighttime. Therefore, the expected arrival time displayed on the display device 5 becomes more accurate, and the driver can know the more accurate predicted arrival time.

  In this embodiment, the CCD camera is used to detect the brightness. However, for example, an illuminance sensor may be provided in the vehicle and the brightness may be detected using the illuminance sensor.

  In each of the above embodiments, only one type is used as the state of the traveling environment of the vehicle to be detected. However, the predicted arrival time may be changed according to a combination of a plurality of types of traveling environment states. For example, as shown in the following fifth embodiment, the predicted arrival time may be changed by combining the first embodiment and the fourth embodiment.

Hereinafter, a navigation system according to a fifth embodiment will be described. This navigation system has the same configuration as that of the first embodiment, but the control unit 4 determines whether the weather is fine, rain, snow, or the other based on the image data of the CCD camera 6. In addition to the determination, it is different in that it is determined whether the brightness is in the daytime state, the nighttime state, or any other state. The control of the navigation system, the step S ₄ to calculate the predicted travel time T by varying the average time T ₀ is different from the first embodiment. This step S _4, it will be described with reference to FIG.

First, the standard required time T ₀ is set (step S ₅₁ ). Next, on the assumption that the vehicle control system is normal (step S ₅₂ ), when the weather is sunny (step S ₅₃ ), when the brightness is in the daytime, the expected required time T is (T ₀ -AA). ), (T ₀ + BB) is set to the expected required time T when the brightness is in the night state, and T ₀ is set to the expected required time T when the brightness is otherwise (steps S _{54 to} S ₅₈ ). . Similarly, when the weather is rainy (step S ₅₉ ), when the brightness is in the daytime state, (T ₀ + CC) is set to the expected required time T, and when the brightness is in the night state, the predicted required time T is set ( (T ₀ + DD) is set, and (T ₀ + EE) is set as the expected required time T when the brightness is other than that (steps S _{60 to} S ₆₄ ). When the weather is snow (step S ₆₅ ), when the brightness is in the daytime state, (T ₀ + FF) is set to the expected required time T, and when the brightness is in the night state, the predicted required time T is set (T the ₀ + GG), the brightness is at other times to set the _(T 0 + HH) in the expected time T (step _S 66 _~S 70). When the weather is neither sunny, rainy, nor snowy, for example, in the case of a snowstorm, (T ₀ + II) is set as the estimated required time T (step S ₇₁ ). Here, AA to II are correction values such that AA = BB <CC <EE <DD <FF <HH <GG <II. Therefore, the estimated required time T is the shortest when the weather is fine and the brightness is daytime, and is the longest when the weather is snowstorm or the like.

  When this navigation system is used, not only the weather of the driving environment of the vehicle but also the brightness is reflected in the expected arrival time, so the expected arrival time displayed on the display device 5 becomes more accurate and the driver is more accurate. Will be able to know the expected arrival time.

The block diagram of the car navigation system of 1st Embodiment of this invention The figure which shows the example of arrangement | positioning of the car navigation system of FIG. The flowchart which shows control of the car navigation system of FIG. Flow diagram showing the process of step S ₄ in FIG. 3 The block diagram of the car navigation system of 2nd Embodiment of this invention FIG. 5 is a flowchart showing the control of the car navigation system of FIG. The flowchart which shows control of the car navigation system of 3rd Embodiment The flowchart which shows control of the car navigation system of 4th Embodiment Flow chart showing control of car navigation system of fifth embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Destination input device 2 GPS receiver 3 Map information storage device 4 Control part 5 Display device 6 CCD camera

Claims (6)

  A navigation system in which an environmental state detection unit that detects a state of a traveling environment of a vehicle is provided in the vehicle, and an expected arrival time at a destination is changed according to the state of the traveling environment detected by the environmental state detection unit.   Standard travel time calculation means for calculating the standard travel time based on the route from the current position to the destination, and the state of the driving environment in which the standard travel time calculated by the standard travel time calculation means is detected by the environmental condition detection means An estimated required time calculating means for calculating the expected required time by varying the time required, and a time converting means for calculating the expected arrival time by adding the expected required time calculated by the expected required time calculating means to the current time; The navigation system according to claim 1.   Weather determination in which the environmental state detection means determines whether the driving environment of the vehicle is clear or a plurality of weathers including rain based on a CCD camera that captures the front of the vehicle and an image captured by the CCD camera 3. The navigation system according to claim 2, wherein when the weather determination unit determines that the rain is raining, the estimated required time is made longer than when the weather determination unit determines that the weather is sunny.   The environmental state detection means includes an air temperature sensor that detects the air temperature of the traveling environment of the vehicle, and when the air temperature detected by the air temperature sensor is equal to or less than a preset expected freezing temperature, the detected air temperature is the expected freezing temperature. The navigation system according to claim 2 or 3, wherein the estimated required time is made longer than when the time is exceeded.   The environmental state detection means determines whether the road surface is dry or a plurality of states including a wet state based on a CCD camera that captures the road surface on which the vehicle travels and an image captured by the CCD camera. 5. The road surface determination means that performs the operation, and when the road surface determination means determines that the road surface is wet, the expected time required is longer than when the road surface is determined to be dry. The described navigation system.   The environmental state detection means includes a CCD camera or an illuminance sensor that detects the brightness of the driving environment of the vehicle, and when the brightness detected by the CCD camera or the illuminance sensor is dark, than when the detected brightness is bright The navigation system according to claim 2, wherein the estimated required time is increased.

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