JP2015194463A - navigation device and map data update system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigation device and a map data update system capable of reflecting a road traffic situation on map data in real time.SOLUTION: An on-vehicle navigation device 2 which is configured so as to be communicable to a map data center 3 comprises: an atmospheric pressure variation sensor 5 for detecting a variation of a peripheral atmospheric pressure to output as atmospheric pressure variation data; an on-vehicle data conversion unit 6 for, on the basis of the atmospheric pressure variation data which is output by the atmospheric pressure variation sensor 5, calculating a height variation amount along a gravitational acceleration direction of a vehicle; an on-vehicle data analysis unit 7 for generating situation data for update 19 relating to estimation of a road traffic situation from the height variation amount calculated by the on-vehicle data conversion unit 6; and an on-vehicle communication unit 8 for transmitting the situation data for update 19 generated by the on-vehicle data analysis unit 7 to the map data center 3 through a communication unit.

Description

  The present invention relates to a vehicle-mounted navigation device and a map data update system including the navigation device.

  In a system that searches for and displays an optimum route to a destination by an in-vehicle navigation device, information (measurement data) acquired from the sensor using various sensors mounted on a vehicle defined as a probe. It is aggregated and analyzed on the host computer. As a result, the map data managed by the host computer is sequentially updated based on the analysis result, so that the navigation apparatus can always use the latest map data. At this time, even if the road surface is greatly affected by temporary circumstances such as road construction or weather changes, the host computer can estimate the abnormality from the measurement data of the sensor mounted on the vehicle that has passed there. Information regarding the abnormality can be added to the map data.

  For example, Patent Document 1 discloses a technique related to a navigation device that measures vibration of a vehicle using an acceleration sensor mounted on the vehicle, estimates a road surface state from the result, and transmits an estimation result to a host computer. ing.

JP 2001-004382 A

However, the conventional in-vehicle navigation device as described above has the following problems. First, since the physical phenomenon to be measured for estimating the road surface condition is vibration, it is difficult to estimate the road surface condition from a relatively slow displacement of the vehicle. In addition, when the vehicle is traveling on a slope, the output of the acceleration sensor is affected by the slope of the slope. Therefore, the inclination of the vehicle is obtained by some method, and the inclination of the vehicle is interpreted as the sensor output value (road surface condition). It is necessary to use this for estimation.
In order to solve the above-described problems, the present invention provides a navigation device and a map data update system capable of reflecting road traffic conditions on map data in real time.

In order to solve the above-described problems, the invention according to claim 1 is a navigation device that is configured to be communicable via a communication unit with a map data management server that manages map data and is mounted on a vehicle, Pressure variation sensor that detects a variation in the atmospheric pressure and outputs it as pressure variation data, and vehicle-mounted data that calculates the amount of height variation along the gravitational acceleration direction of the vehicle based on the pressure variation data output from the pressure variation sensor A conversion unit, an in-vehicle data analysis unit that generates status data related to estimation of road traffic conditions from the amount of height fluctuation calculated by the in-vehicle data conversion unit, and the status data generated by the in-vehicle data analysis unit via the communication unit And a situation data transmitter for transmitting to the map data management server.
According to the first aspect of the present invention, since the road traffic situation is estimated based on the fluctuation of the surrounding atmospheric pressure by the atmospheric pressure fluctuation sensor, the road traffic situation can be reflected in the map data in real time.

In the invention according to claim 2, the in-vehicle data analysis unit frequency-analyzes the height variation data, and determines the unevenness state of the road surface from the first frequency among the analyzed frequency components, and determines The situation data is generated based on the uneven state.
According to the second aspect of the present invention, it is possible to reflect the information regarding the fine uneven state of the road surface in the map data.

According to a third aspect of the present invention, the in-vehicle data analyzing unit determines an inclination state of a road surface from the second frequency among the analyzed frequency components, and the situation data is based on the determined inclination state. Is generated.
According to the third aspect of the present invention, information relating to the slope of the road surface can be reflected in the map data.

In the invention according to claim 4, the in-vehicle data analysis unit determines a congestion state of a road from a third frequency component different from the first and second frequency components among the analyzed frequency components. The situation data is generated based on the determined congestion situation.
According to the fourth aspect of the present invention, the road congestion state can be reflected in the map data.

In the invention according to claim 5, the road congestion state determined by the in-vehicle data analysis unit is a congestion state related to a lane adjacent to a lane in which the vehicle travels or an opposite lane.
According to the fifth aspect of the present invention, the congestion state of the lane other than the lane in which the vehicle on which the navigation device is mounted is traveling can be reflected in the map data.

According to a sixth aspect of the present invention, the vehicle-mounted data analysis unit includes a vehicle speed transmission unit that acquires speed information related to the speed of the vehicle and transmits the acquired speed information to the vehicle-mounted data analysis unit. A three-dimensional trajectory of the vehicle is calculated based on a height fluctuation amount and the speed information, and the situation data is generated based on the calculated trajectory.
According to the sixth aspect of the present invention, accurate information on road surface irregularities and three-dimensional shapes of steps can be reflected in map data.

Further, in the invention according to claim 7, the vehicle data analysis unit includes a situation database unit that stores the height fluctuation amount and situation data corresponding to the height fluctuation amount for each height fluctuation amount. The situation data according to the height fluctuation amount calculated by the in-vehicle data conversion unit is extracted from the situation database unit.
According to the seventh aspect of the present invention, the situation can be accurately calculated in a short time from the height fluctuation amount.

The invention according to claim 8 further includes a search unit that searches for an optimum route from a departure point to an arrival point under a given route search condition, and the search unit uses the situation data to It is characterized by searching for an optimum route.
According to the eighth aspect of the invention, it is possible to always search for the optimum route using the latest detailed road conditions.

The invention according to claim 9 further includes a time data generation unit that generates time data related to a time when the atmospheric pressure fluctuation sensor detects the atmospheric pressure fluctuation, and the situation data transmission unit includes the situation data and the situation data The time data is transmitted to the map data management server.
According to the invention described in claim 9, the map data management server can grasp how new the generated situation data is.

In the invention according to claim 10, the atmospheric pressure variation sensor includes a cavity having a predetermined volume, a communication hole through which a pressure transmission medium for transmitting atmospheric pressure flows inside and outside the cavity, and a reference that varies according to atmospheric pressure variation. And an output unit that outputs atmospheric pressure fluctuation data relating to a differential pressure between an internal pressure corresponding to a pressure and representing an internal pressure of the cavity, and an ambient pressure.
According to the tenth aspect of the present invention, it is possible to reflect highly accurate information on the map data by detecting minute up and down movements of the vehicle by detecting minute pressure fluctuations.

In the invention according to claim 11, the in-vehicle data conversion unit includes a differential pressure calculation unit that obtains a differential pressure between the internal pressure and the ambient atmospheric pressure based on the atmospheric pressure fluctuation data, and a set value of the internal pressure and the differential pressure calculation unit. Based on the differential pressure calculated by the above, the pressure calculation unit that calculates the ambient pressure, and the flow per predetermined time of the pressure transmission medium that flows inside and outside the cavity based on the differential pressure calculated by the differential pressure calculation unit Based on the flow rate calculation unit for calculating the amount, the flow rate calculated by the flow rate calculation unit and the volume of the cavity, the internal pressure after a predetermined time is calculated, and the internal pressure used in the pressure calculation unit with the calculated internal pressure is calculated. An internal pressure update unit for updating the set value.
According to the eleventh aspect of the present invention, it is possible to detect minute vertical movements of the vehicle by accurately detecting ambient pressure fluctuations, and to reflect highly accurate information in map data.

In the invention according to claim 12, the atmospheric pressure fluctuation sensor is provided so as to close the opening surface of the cavity excluding the communication hole, and has a cantilever that bends and deforms in accordance with the differential pressure, and the output portion is a cantilever of the cantilever. Pressure variation data corresponding to the deflection amount is output.
According to the invention of the twelfth aspect, by outputting a signal corresponding to slight atmospheric pressure fluctuation, it is possible to detect a minute vertical movement of the vehicle and to reflect highly accurate information on the map data.

Moreover, in invention of Claim 13, it is a map data update system containing the navigation apparatus as described in any one of Claims 1-12, and the said map data management server, Comprising: The said map data management server Comprises a map data creation unit for creating new map data based on the situation data received from the navigation device.
According to the invention described in claim 13, the map data management server can always store the map data reflecting the latest road traffic situation and provide the information to the navigation device of each vehicle.

In the invention according to claim 14, the navigation device has a position data acquisition unit that acquires current position data representing a current position, and the situation data includes the current data acquired by the position data acquisition unit. Estimated information regarding the height fluctuation of the road at the position is included, and the map data management server includes the map data with predetermined position data at the predetermined position and information regarding the height fluctuation of the road near the predetermined position. When the situation data is received from the navigation device and the distance between the current position and the predetermined position is smaller than a predetermined value, the estimated information on the height fluctuation of the situation data and the map data It is determined by the height variation determining unit that determines whether or not the information about the height variation matches, and by the height variation determining unit. A position data transmission unit that transmits the predetermined position data to the navigation device, and the navigation device uses the predetermined position data transmitted from the position data transmission unit by the position data acquisition unit. The present position data is corrected.
According to the invention described in claim 14, even when the current position recognized by the vehicle is slightly deviated from the actual position, the deviation is corrected by communication with the map data management server. , You can always grasp the exact current position.

In the invention according to claim 15, the map data creation unit of the map data management server sets a validity period of the situation data, and discards the situation data when the validity period is exceeded. Features.
According to the fifteenth aspect of the present invention, it is possible to perform an accurate route search by storing only new and valid status data in the map data.

The invention according to claim 16 is a map data updating system including the navigation device according to claim 7 and the map data management server, wherein the navigation device is stored in the situation database unit. A progress determination unit that determines whether or not a predetermined time has elapsed from when the navigation device is mounted on the vehicle, and a progress determination unit. Temporary situation data that causes the in-vehicle data analysis unit to generate the situation data and transmits the situation data as temporary situation data to the map data management server via the communication unit when it is determined that And the map data management server stores map data associated with situation data in advance. A match that determines whether the figure data storage unit, the temporary status data transmitted by the temporary status data transmission unit, and the status data corresponding to the map data stored in the map data storage unit match. A determination unit, and a transmission status data transmission unit that transmits status data corresponding to the map data to the navigation device as transmission status data when the match determination unit determines that they do not match, The navigation device includes a situation data storage unit that stores the situation data for sending in the situation database unit as situation data when the situation data for sending is transmitted by the situation data sending unit for sending. It is characterized by that.
According to the sixteenth aspect of the present invention, by creating a situation database incorporating performance characteristics unique to each navigation device, it is possible to reduce erroneous analysis due to performance variations of the navigation device.

The invention according to claim 17 is a map data update system including the navigation device according to claim 9 and the map data management server, wherein the map data management server includes a plurality of the navigation devices. And a map data creating unit for creating new map data based on the situation data corresponding to the latest time data among the situation data transmitted from the plurality of navigation devices.
According to the invention described in claim 17, it is possible to always have map data that grasps the latest situation data.

  According to the present invention, map data can have more detailed and real-time information, and a route search and information provision using the map data can be performed. That is, the navigation device and the map data update system according to the present invention can reflect the road traffic situation in the map data in real time.

It is a block diagram which shows the structure of the map data update system in 1st Embodiment of this invention. (A) (b) It is a figure which shows the example which converted the height variation data in 1st Embodiment of this invention into the frequency component. It is a structure figure showing the data structure of map data in a 1st embodiment of the present invention. It is a structural diagram which shows the data structure of the traffic data in 1st Embodiment of this invention. It is a flowchart which shows the characteristic operation | movement of the map data update system in 1st Embodiment of this invention. It is a flowchart which shows the characteristic operation | movement of the map data update system in 2nd Embodiment of this invention. It is a block diagram which shows the structure of the map data update system in 3rd Embodiment of this invention. It is a block diagram which shows the structure of the map data update system in 5th Embodiment of this invention. It is a block diagram which shows the structure of the map data update system in 6th Embodiment of this invention. It is a flowchart which shows the characteristic operation | movement of the map data update system in 6th Embodiment of this invention. It is a top view which shows the structure of the pressure sensor 71 in 7th Embodiment of this invention. It is sectional drawing of the pressure sensor 71 along the AA line shown in FIG. It is a figure which shows an example of the output of the pressure sensor 71 shown in FIG. It is a figure which shows an example of the output of the pressure sensor 71 shown in FIG. It is explanatory drawing which shows the flow of the process which calculates the moving amount | distance of the up-down direction which the vehicle-mounted data conversion part 6 shown in FIG. 1 performs.

(First embodiment)
1st Embodiment of the map data update system which concerns on this invention is described using FIGS.
FIG. 1 is a block diagram showing a configuration of a map data update system 1 in the first embodiment of the present invention. The map data update system 1 includes one or a plurality of in-vehicle navigation devices 2 (navigation devices) and a map data center 3 (map data management server) configured to be able to communicate with the in-vehicle navigation devices 2 via a network.

  The in-vehicle navigation device 2 is an in-vehicle navigation device mounted on a vehicle owned by a user who has registered for use in the map data update system 1. The map data center 3 is a server device for realizing functions such as aggregating information transmitted from each in-vehicle navigation device 2 to update the map data and providing the map data to the in-vehicle navigation device 2. .

"Configuration of the in-vehicle navigation system"
The in-vehicle navigation device 2 includes an in-vehicle control unit 4 for comprehensively controlling each part of the in-vehicle navigation device 2, an atmospheric pressure fluctuation sensor 5 for detecting an atmospheric pressure fluctuation amount of the vehicle, and an atmospheric pressure fluctuation amount detected by the atmospheric pressure fluctuation sensor 5. The vehicle-mounted data conversion unit 6 that calculates the height variation amount of the vehicle on which the vehicle-mounted navigation device 2 is mounted, and the road traffic condition from the height variation amount calculated by the vehicle-mounted data conversion unit 6 The in-vehicle data analysis unit 7 that generates update status data 19 (situation data) related to the estimation, the in-vehicle communication unit 8 (situation data transmission unit) that transmits the update status data 19 to the map data center 3, and the in-vehicle navigation device 2 A location information acquisition unit 9 that acquires the location information, a map data storage unit 11 that stores the map data 10, and a search unit 12 that searches for the optimum route from the departure point to the destination.

  The in-vehicle control unit 4 includes, for example, a CPU, a RAM, a ROM, and the like (not shown), and the CPU expands and executes various control programs stored in the ROM on the RAM. It is a central control part which controls each part and the whole of the vehicle-mounted navigation apparatus 2.

  The position information acquisition unit 9 includes a GPS receiver that receives a GPS signal transmitted from a GPS satellite, and generates current position data representing the current position (own vehicle position) of the vehicle (vehicle-mounted navigation device 2). .

  The atmospheric pressure fluctuation sensor 5 is a sensor element that measures and outputs the ambient atmospheric pressure. In particular, the atmospheric pressure fluctuation sensor 5 has an atmospheric pressure fluctuation output function that detects fluctuations in the surrounding atmospheric pressure and outputs the detected values to the outside as atmospheric pressure fluctuation data.

  The in-vehicle data conversion unit 6 receives the atmospheric pressure fluctuation data output from the atmospheric pressure fluctuation sensor 5 and converts the atmospheric pressure fluctuation data into a height fluctuation amount along the direction of gravitational acceleration of the vehicle using a predetermined conversion method. Here, since the atmospheric pressure depends on the position along the direction of gravity, when the vehicle moves up and down, the corresponding atmospheric pressure fluctuation occurs. Therefore, the in-vehicle data conversion unit 6 can calculate the vehicle height fluctuation amount by substituting the atmospheric pressure fluctuation amount related to the atmospheric pressure fluctuation data into a predetermined conversion formula or referring to a predetermined atmospheric pressure altitude correspondence table. Here, the predetermined conversion formula is that the measured atmospheric pressure at an arbitrary time t1 is P1, and the measured atmospheric pressure at a time t2 different from t1 is P2, and the difference between the vehicle height at t1 and the vehicle height at t2 (height fluctuation) (Quantity) Δh is an expression for obtaining P1 and P2, and for example, an expression such as expression (1) is known.

Δh = 18410.0 × (log10P1-log10P2) (1)
Here, the unit of the height fluctuation amount Δh is meter [m], and the unit of the measured atmospheric pressures P1 and P2 is hectopascal [hPa]. Note that the height fluctuation amount of the vehicle can be calculated from the atmospheric pressure fluctuation amount by preparing a barometric altitude correspondence table incorporating temperature information at that time in advance and referring to the table.
Further, the in-vehicle data conversion unit 6 transmits height variation data representing the converted height variation amount to the in-vehicle data analysis unit 7.

The in-vehicle data analysis unit 7 generates update situation data 19 related to the estimation of the road traffic situation based on the height fluctuation data transmitted from the in-vehicle data conversion unit 6. Here, the “road traffic situation” in the present embodiment refers to the road situation regarding whether or not the road surface is uneven or stepped, whether or not the road surface is an inclined surface (slope), the lane in which the vehicle travels, It is a concept including a traffic situation indicating a congestion state of a lane adjacent to a lane or an opposite lane.
The generation process of the update status data 19 executed by the in-vehicle data analysis unit 7 is as follows. The height fluctuation data is data indicating the amount of height fluctuation (in time series) in the time domain.

  First, the in-vehicle data analysis unit 7 performs frequency analysis on the height variation data and separates it into frequency components. Here, there are a plurality of causes that cause the vehicle to move up and down, such as road surface unevenness, steps, and road inclination. Of these, the unevenness of the road surface causes a fluctuation in height of several millimeters or more from the road surface, such as a break in a paved road and gravel on the road surface. Further, the level difference causes a height fluctuation of about several centimeters or more that occurs when a vehicle rides on a sidewalk or parking lot from a roadway. Furthermore, the inclination of the road causes a height fluctuation of about several meters or more that occurs when the road itself is a slope. In other words, the vertical movement of the vehicle caused by each factor has a difference in the height fluctuation amount on the scale, and the difference in the scale appears as a frequency difference in the frequency analysis. Therefore, the in-vehicle data analysis unit 7 can easily separate the frequency fluctuation data into the frequency components for each factor of the vertical movement by converting the height variation data into the frequency components.

  2A and 2B are examples in which the height variation data is converted into frequency components. The horizontal axis f represents frequency, and the vertical axis A represents signal intensity. The frequency components of the height variation data are defined by a first frequency threshold f1 and a second frequency threshold f2 (> f1), a low frequency region (f <f1), a middle frequency region (f1 <f <f2), and a high frequency region (f2 < f). The presence or absence of a peak is determined by the magnitude relationship between the signal intensity and the intensity threshold value At.

  First, FIG. 2A shows an example in which peak p1 is observed in the low frequency region and peak p2 is observed in the high frequency region for the converted height variation data. The presence of the low frequency component (second frequency) suggests that the road is a slope (inclined road surface). The presence of the high frequency component (first frequency) suggests that there are fine irregularities on the road surface (road surface irregularity state). Further, the absence of the medium frequency component suggests that there is no step such as riding on the sidewalk or parking lot from the above-described roadway. From these facts, in the case of FIG. 2A, the in-vehicle data analysis unit 7 can estimate that the vehicle is traveling on a slope having fine irregularities such as gravel.

Next, FIG. 2B is a diagram exemplifying a case where the peak p3 is observed in the middle frequency region and the signal intensity in other frequency regions is low. From these facts, in the case of FIG. 2 (b), the in-vehicle data analysis unit 7 can estimate that there is a step such as riding on the sidewalk or parking lot from the roadway described above on the road surface paved on a flat ground.
The in-vehicle data analysis unit 7 thus estimates the cause by using the frequency domain threshold and the amplitude threshold from the frequency component of the height variation data.

  Here, as described above, since the atmospheric pressure fluctuation sensor 5 is composed of a cantilever type differential pressure sensor, it is not affected at all by the attitude of the sensor itself, and is up and down from several millimeters to several tens of meters per second. It has the feature that movement can be detected with one sensor. Therefore, the in-vehicle data analysis unit 7 according to the present embodiment uses the characteristics of the atmospheric pressure fluctuation sensor 5 to measure from a fine road surface unevenness, a step, and a hill on which the vehicle has passed with a single sensor. The situation can be estimated. The estimation result regarding the road condition of the in-vehicle data analysis unit 7 obtained in this way is referred to as update situation data 19. In the present embodiment, the situation data 19 includes, for example, a complicated situation in which “a step with a height of 10 cm having a concavo-convex of 1 cm on the surface is in the middle of a slope with a height difference of 10 meters”. Can be expressed easily from the output of.

  Since the atmospheric pressure fluctuation sensor 5 does not use a GPS signal at the time of detection, the atmospheric pressure fluctuation data can be output with the same accuracy even indoors where it is difficult to receive the GPS signal. Therefore, the in-vehicle data analysis unit 7 can generate the update status data 19 even indoors such as in a tunnel or a multilevel parking lot.

  The in-vehicle communication unit 8 includes, for example, an interface for wireless communication, and is configured to be able to transmit / receive data to / from the map data center 3 via a network. The in-vehicle communication unit 8 transmits the update status data 19 acquired from the in-vehicle data analysis unit 7 and the current position data acquired from the position information acquisition unit 9 to the map data center 3. The in-vehicle navigation device 2 includes a time data generation unit (not shown), and generates time data that is time information when the air pressure fluctuation sensor 5 measures the air pressure fluctuation, separately from the update situation data 19. Then, it can be transmitted to the map data center 3 simultaneously with the update status data 19 via the in-vehicle communication unit 8. Further, the in-vehicle communication unit 8 receives the search status data 20 from the map data center 3 to be described later and transmits it to the search unit 12.

  The map data storage unit 11 is configured by a hard disk drive or the like, and stores map data 10 that is used when executing route guidance processing by the in-vehicle navigation device 2. Here, FIG. 3 is a data structure diagram showing the structure of the map data 10. The map data 10 includes road data 21, background data 22, character data 23, and guidance data 24. The road data 21 is data used for displaying a map or displaying the current position via a user interface unit (not shown) configured such that the in-vehicle navigation device 2 includes a monitor device and the like. The road data 21 includes position information and information related to the estimation of the road traffic situation at the position related to the position information (information corresponding to the update situation data 19). The background data 22 and the character data 23 are data used for displaying a background and characters when displaying a map, respectively. The guidance data 24 is data used for guidance, such as the name of an intersection.

  The search unit 12 combines a route search condition such as a destination input from the user via the user interface unit, the current position obtained from the position information acquisition unit 9, and the search situation data 20. A process for searching for the optimum route from the ground (departure point to arrival point) is performed. Then, the search unit 12 notifies the user of the result via the user interface unit (performs the user with route guidance based on the optimal route).

“Configuration of the map data center”
The map data center 3 includes a center control unit 13 for overall control of each part of the map data center 3, a center map data storage unit 15 for storing center map data 14, and a traffic data storage unit 17 for storing traffic data 16. And a center communication unit 18 configured to be communicable with the in-vehicle communication unit 8.

  The center control unit 13 includes, for example, a CPU, a RAM, a ROM, and the like (not shown), and the CPU develops and executes various control programs stored in the ROM on the RAM. It is a central control unit that controls each part and the whole of the map data center 3. The center control unit 13 functions as, for example, a map data creation unit that creates new center map data 14 based on the update status data 19 received from the navigation device 2.

  The center map data storage unit 15 is composed of a hard disk drive or the like, and stores center map data 14 that is map data used in the map data center 3. Here, the data structure of the center map data 14 is a structure having the data items of the map data 10 of the in-vehicle navigation device 2 shown in FIG. 3, and includes road data 21, background data 22, character data 23, and guidance data 24. Including. The center map data 14 is different from the map data 10 of the in-vehicle navigation device 2 in that the center map data 14 is always updated to the latest information by a data update process described later.

The traffic data storage unit 17 is composed of a hard disk drive or the like, and stores the traffic data 16. Here, FIG. 4 is a structural diagram showing the structure of the traffic data 16. The traffic data 16 includes traffic jam data 31, traffic regulation data 32, required time data 33, traffic fault data 34, and road condition data 35. The traffic jam data 31 and the traffic regulation data 32 are data indicating information on traffic jams and traffic regulation in various places at the present time, respectively. The required time data 33 is data indicating information related to the current required time between major points. The traffic obstacle data 34 is data indicating information related to a traffic obstacle such as an interruption due to an accident or a disaster. The road condition data 35 is data indicating information on the presence or absence of road surface unevenness or steps and the position thereof.
Here, the traffic jam data 31 and the road situation data 35 have a data configuration including position information and information corresponding to the update situation data 19 at the position related to the position information.

(About update processing of center map data and traffic data)
Next, center map data and traffic data update processing by the center control unit 13 will be described.
When the center control unit 13 receives the update status data 19 and the current position data acquired by the position information acquisition unit 9 from the in-vehicle navigation device 2 via the center communication unit 18, the center control unit 13 receives the update status data 19 and the current position data. The center map data 14 and the traffic data 16 are collated, and it is determined whether there is information already held as the road condition at the current position of the vehicle on the center map data 14. Data is added to the traffic data 16 or both. At this time, if there is already held information, it is overwritten. In this way, the center map data 14 and the traffic data 18 always have the latest and detailed information using the road surface conditions obtained by the vehicle traveling. As described above, the update status data 19 includes various information such as slopes, steps, and unevenness. Therefore, when the center control unit 13 receives the update status data 19 from the center communication unit 18, the center control unit 13 classifies the inside of the update status data 19 and considers that there is no change for at least several months like the presence or absence of a slope. And data that may change in a few days or hours, such as fine irregularities on the road surface. Then, the center control unit 13 adds or overwrites the information to the center map data 14 (the road data 21 thereof) for the data that does not change. On the other hand, the center control unit 13 adds or overwrites the changing data to the traffic data 16 (any one of the traffic jam data 31 and the road condition data 35).

  Here, since the in-vehicle navigation device 2 is mounted on a vehicle owned by each user who has registered for use in the map data update system 1, the map data center 3 is always used for updating from a large number of in-vehicle navigation devices 2. Status data 19 is transmitted. Then, the center control unit 13 updates the center map data 14 and the traffic data 16 using the update status data 19 having the latest time data. As a result, the map data center 3 always stores the latest information in real time. The search unit 12 of the in-vehicle navigation device 2 can always search for a route by using the latest road traffic situation by communicating with the map data center 3.

"Map data update process by map data update system"
Next, map data update processing executed in the map data update system 1 of the present embodiment will be described using the flowchart shown in FIG. In this flowchart, among the plurality of in-vehicle navigation devices 2, the one that transmits the update status data 19 to the map data sensor 3 is transmitted to the in-vehicle navigation device 2a and the map data sensor 3 to perform a route search. What is to be performed is an in-vehicle navigation device 2b.

  First, the in-vehicle navigation device 2a detects a change in ambient atmospheric pressure by the atmospheric pressure fluctuation sensor 5, and outputs the detected value as atmospheric pressure fluctuation data (step S1). Next, the in-vehicle navigation device 2a calculates a height variation amount along the direction of gravity acceleration of the vehicle from the atmospheric pressure variation data output in step S1 by the in-vehicle data conversion unit 6 (step S2). Next, the in-vehicle navigation device 2a estimates the road traffic situation based on the height fluctuation data calculated in step S2, and generates the update situation data 19 (step S3). Next, the in-vehicle navigation device 2a transmits the update status data 19 generated in step S3 by the in-vehicle communication unit 8 to the map data center 3 (step S4).

  Next, the map data center 3 classifies the update status data 19 transmitted from the in-vehicle navigation device 2a in step S4 into data that does not change in a short time and data that changes (step S5). Next, the map data center 3 updates the center map data 14 and the traffic data 16 based on the classification result of the update status data 19 (step S6).

  Next, the in-vehicle navigation device 2b transmits a search notification related to a route search request to the map data center 3 (step S7). At this time, the in-vehicle navigation device 2b also transmits own vehicle position data related to the current position of the own device (own vehicle) to the map data center 3. Next, when the map data center 3 obtains the search notification according to step S7, the map data center 3 selects data necessary for the search from the center map data 14 and the traffic data 16, and transmits the data as search status data 20 to the in-vehicle navigation device 2b. (Step S8). Next, the in-vehicle navigation device 2b uses the search unit 12 to search for the optimum route using the current position data, the map data 10, and the search situation data 20 (step S9). When this search is performed, a more appropriate route can be searched by using the search status data 20 in addition to the map data 10. For example, when a route found as an optimal route candidate has a short mileage, but the pavement state is bad or there are many steps, it may not always be optimal when considering the influence. The route search is performed in consideration of these situations. Next, the in-vehicle navigation device 2b starts route guidance using the route data searched in step S9 (step S10).

  Note that the data classified as data that changes in a short time in step S5 is the center map data 14 or the traffic data 16 after a predetermined time (the validity period of the update status data 19 determined by the center control unit 13) has passed. Delete from.

  As described above, according to the map data update system 1 according to the present embodiment, the optimum route can be searched based on the data obtained in real time from the roads and traffic conditions transmitted from each of the vehicles registered in the system. A very accurate route guidance can be realized.

(Second Embodiment)
A second embodiment of the map data update system according to the present invention will be described with reference to FIGS. In addition, since the structure of the map data update system 1 is the same as that of 1st Embodiment, description is abbreviate | omitted.

  In the present embodiment, markers (predetermined position data) and marker information are defined in advance in the center map data 14 in the map data center 3. The marker represents the coordinates of the point when it is known that a specific step exists at the specific point, and the marker information is information regarding the road traffic situation at the point. Here, the marker information is information related to road traffic conditions, for example, information related to a step at the entrance from the roadway to the parking lot, or a stepped pavement for speed regulation (information related to a change in the height of the road near a predetermined position). is there. That is, the position and height of the step are included in the center map data 14 as marker information. The update data 19 when the vehicle passes through the marker is already known by the map data center 3 before being transmitted from the in-vehicle navigation device 2, so that the vehicle position is finely adjusted using this. System.

"Position adjustment processing by map data update system"
Next, the position adjustment process executed in the map data update system 1 of the present embodiment will be described using the flowchart shown in FIG. Here, FIG. 6 is a flowchart showing a characteristic operation of the map data update system 1 in the second embodiment of the present invention.

  First, in step S21, the map data center 3 receives the vehicle position data (current position data acquired from the position information acquisition unit 9) and the update status data 19 from the in-vehicle navigation device 2. Next, in step S22, the center control unit 13 determines whether or not the company position related to the vehicle position information is in a region within a predetermined distance from the marker (functions as a determination unit). Here, an area within a predetermined distance from the marker is referred to as a marker area.

  When the center control unit 13 determines that the vehicle position is within the marker area (step S22; Y), in step S23, the center control unit 13 determines whether the update situation data 19 matches the marker information. If the center control unit 13 determines that it does not match the marker information (step S23; N), it is within the marker area but has not passed the marker, so information for updating the vehicle position is obtained. Therefore, the process returns to step S21.

  On the other hand, if the center control unit 13 determines that it matches the marker information (step S23; Y), the process proceeds to step S24, where the position coordinates of the marker are transmitted to the in-vehicle navigation device 2 as the corrected vehicle position (ie, The center control unit 13 functions as a position data transmission unit).

Next, the in-vehicle navigation device 2 (position information acquisition unit 9) overwrites and corrects the own vehicle position related to the own vehicle position information transmitted in step S21 with the corrected own vehicle position received in step S24 (step S25). ). In addition, although the own vehicle position information and the corrected own vehicle position may coincide, there is no influence because it is not changed even if overwritten. In the present embodiment, unlike the first embodiment, if there is a mismatch between the update status data 19 and the center map data 14, the center map data 14 is prioritized. That is, without overwriting the center map data 14, the vehicle position of the vehicle is adjusted so that the update status data 19 and the center map data 14 are matched.
Thus, by updating the vehicle position using not only GPS but also the marker, the vehicle position can be accurately grasped with an accuracy of about centimeters.

(Third embodiment)
A third embodiment of the map data update system according to the present invention will be described with reference to FIG.
FIG. 7 is a block diagram showing the configuration of the map data update system 41 in the third embodiment of the present invention. In addition, the same code | symbol is provided about the same structure as 1st Embodiment among the structures of the map data update system 41 which concerns on this embodiment, and the description is abbreviate | omitted. The in-vehicle navigation system 42 according to the present embodiment includes a vehicle speed acquisition unit 43 that measures the vehicle speed (vehicle speed data) of a vehicle in which the in-vehicle navigation device 42 is mounted. The in-vehicle data analysis unit 7 performs data analysis using the vehicle speed data acquired by the vehicle speed acquisition unit 43.

  The vehicle speed acquisition unit 43 is connected to a computer (not shown) mounted on the vehicle, and is configured to acquire vehicle speed data by obtaining a vehicle speed pulse signal from the computer. The vehicle speed acquisition unit 43 functions as a vehicle speed transmission unit that transmits the acquired vehicle speed data (speed information) to the in-vehicle data analysis unit 7.

  The in-vehicle data analysis unit 7 acquires height variation data from the in-vehicle data conversion unit 6, acquires current position data from the position information acquisition unit 9, and acquires vehicle speed data from the vehicle speed acquisition unit 43. And the vehicle-mounted data analysis part 7 calculates the locus | trajectory in the three-dimensional space of a vehicle by combining these data. In other words, the in-vehicle data analysis unit 7 estimates the road traffic situation described in the previous embodiment, and analyzes the uneven shape of the road surface and the three-dimensional shape of the step from the calculated locus in the three-dimensional space, What these objects are, for example, objects that form unevenness and steps such as gravel and curb are estimated, and the estimated information is added to the update status data 19. Therefore, the center control unit 13 of the map data center 3 that has acquired the update situation data 19 can add more detailed and specific information regarding the estimation of the road traffic situation to the center map data 14.

(Fourth embodiment)
A fourth embodiment of the map data update system according to the present invention will be described.
The configuration of the map data update system 41 of the fourth embodiment is the same as that of the map data update system 41 of the third embodiment.

  In the map data update system 41 of the present embodiment, when the in-vehicle data conversion unit 6 converts the atmospheric pressure fluctuation data from the atmospheric pressure fluctuation sensor 5, the atmospheric pressure fluctuation is not only due to the vertical movement of the vehicle but also due to the passing of other vehicles. It is a point which isolate | separates the atmospheric | air pressure fluctuation component by them in consideration of generating. Note that the position information acquisition unit 9 according to the present embodiment is based on the acquired current position data and the road data 21 in the map data 10 (information on the number of lanes and the lane width included therein). Information on whether the vehicle is traveling on a single lane or which lane of two or more lanes is being traveled can be acquired.

Specifically, the in-vehicle data conversion unit 6 performs the frequency analysis described in the first embodiment on the atmospheric pressure fluctuation data output from the atmospheric pressure fluctuation sensor 5, and the component of the middle frequency region (third frequency component). Check for presence. Furthermore, the in-vehicle data conversion unit 6 determines whether or not the atmospheric pressure increases and then returns to the original value during a predetermined time (for example, 1 second) in the time-series change of the signal intensity in the medium frequency region component. Confirm. Furthermore, the in-vehicle data conversion unit 6 confirms whether or not the vehicle speed obtained from the vehicle speed acquisition unit 43 in the predetermined time is equal to or higher than a predetermined value (for example, 5 kilometers per hour). The above confirmation items are characteristics of atmospheric pressure fluctuations that occur due to passing by other vehicles. Here, since the predetermined time and the predetermined value differ depending on the vehicle and also on the driver, it is possible to optimize by collecting and analyzing data after the vehicle is started. If all of the above confirmation items are satisfied, it is estimated that the pressure fluctuation data of the relevant part is generated by passing with another vehicle.
In this way, since the in-vehicle data conversion unit 6 can separate the atmospheric pressure fluctuation generated by passing with other vehicles from the atmospheric pressure fluctuation data, the in-vehicle data analysis unit 7 for acquiring the separated atmospheric pressure fluctuation data is By combining the speed information (vehicle speed data) of the own vehicle obtained from the vehicle speed acquisition unit 43, not only the situation relating to the road on which the own vehicle is traveling, but also the situation relating to the adjacent lane or the oncoming lane, such as traffic jam information (congestion of the road) Situation) can be estimated.

  Specifically, the in-vehicle data analysis unit 7 performs the estimation process according to the following procedure. First, the in-vehicle data analysis unit 7 obtains information on whether the vehicle is traveling on a one-lane road or one of two or more lanes from the position information acquisition unit 9. Here, the pressure fluctuation generated when the own vehicle passes another vehicle traveling in the lane adjacent to the own vehicle is generated by passing the other vehicle traveling further in the adjacent lane. It is much larger than atmospheric pressure fluctuation. For this reason, the in-vehicle data analysis unit 7 performs an approximation considering only the passing with the vehicle traveling in the adjacent lane among the passing with other vehicles. Further, the in-vehicle data analysis unit 7 further combines the current travel lane, the vehicle speed, and the pressure fluctuation data, so that the speed of the vehicle traveling in the adjacent lane in the same direction or the vehicle traveling in the opposite lane. The speed can be estimated, and thereby the congestion situation of the adjacent lane and the oncoming lane can be estimated.

The in-vehicle navigation device 2 transmits update status data 45 including the estimated information to the map data center 3. Note that the update status data 45 includes information about the time when the atmospheric pressure fluctuation sensor 5 measures the atmospheric pressure fluctuation amount, as in the first embodiment. Here, the traffic situation (road congestion situation) changes greatly with the passage of time. Therefore, the map data center 3 performs processing for excluding information related to traffic jams from the traffic data 16 when a predetermined time, for example, one day has passed, in the update status data 45.
In this way, the center control unit 13 of the map data center 3 can add more detailed and various types of specific information regarding the traffic congestion state to the traffic data 16.

(Fifth embodiment)
A fifth embodiment of the map data update system according to the present invention will be described with reference to FIG.
FIG. 8 is a block diagram showing the configuration of the map data update system 51 in the fifth embodiment. In the configuration of the map data update system 51 shown in FIG. 8, the same parts as those of the map data update system 1 shown in FIG.

The present embodiment is different from the first embodiment in that the in-vehicle navigation device 52 further includes a situation database 53 (situation database unit).
The situation database 53 is a database that stores in advance, for each height variation amount, a vehicle height variation amount and situation data corresponding to the height variation amount.

  That is, when the in-vehicle data analysis unit 7 acquires the height variation data from the in-vehicle data conversion unit 6, the in-vehicle data analysis unit 7 creates the update situation data 19 by referring to the situation database 53 from the height variation amount related to the height variation data To do. When the in-vehicle data analysis unit 7 determines that the height variation amount corresponding to the height variation data is not stored in the situation database 53, the in-vehicle data analysis unit 7 obtains the newly estimated situation data. It can also be stored in the situation database 53 in association with the height fluctuation data at the time of estimation. Thus, the in-vehicle data analysis unit 7 can also have a learning function that gradually improves the accuracy of the analysis (estimation) of the road traffic situation by sequentially adding and updating the situation database 53. With such a configuration, the map data update system 51 has the center map data 14 and the traffic data 16 with higher accuracy and higher accuracy, and enables an accurate route search.

(Sixth embodiment)
A sixth embodiment of the map data update system according to the present invention will be described with reference to FIGS. 9 and 10.
FIG. 9 is a block diagram showing a configuration of the map data update system 61 according to the sixth embodiment of the present invention, and FIG. 10 is a flowchart showing its characteristic operation.

  In FIG. 9, the same parts as those in FIG. In the present embodiment, a predetermined period after the in-vehicle navigation device 62 is mounted on the vehicle is defined as a calibration period, and the in-vehicle control unit 4 (calibration unit, progress determination unit, provisional status data transmission of the in-vehicle navigation device 62 is transmitted. And the situation data storage unit) execute the calibration process of the situation database 53 (situation data) in cooperation with the center control unit 9 (match judgment unit, sending situation data transmission unit) of the map data sensor 3. It is. The calibration period is that the vehicle has repeatedly traveled a plurality of times in a travel area where the vehicle travels frequently, such as a period until the cumulative travel distance of the vehicle from the time of installation reaches 1000 kilometers. It is set to a certain period. This setting may be changed by the user via an interface unit of the in-vehicle navigation device 62 (not shown).

  The difference between the map data update system 61 shown in FIG. 9 and the map data update system 51 shown in FIG. 8 is that the update status indicating that the data transmitted from the in-vehicle navigation device 62 to the map data center 3 is temporary status data. This is a data candidate 63 and the data transmitted from the map data center 3 to the in-vehicle navigation system 62 is the DB correction status data 64.

(Calibration process by map data update system)
Next, calibration processing by the map data update system 61 according to the present embodiment will be described with reference to FIG.
First, the vehicle-mounted control unit 4 determines whether or not the time measured by a clock unit (not shown) corresponds to the calibration period (step S61). When the in-vehicle control unit 4 determines that it is not the calibration period (step S61; N), the in-vehicle control unit 4 proceeds to the normal operation described in the above embodiment (for example, the flow execution operation illustrated in FIG. 5). On the other hand, when it is determined that it is the calibration period (step S61; Y), the in-vehicle control unit 4 detects the atmospheric pressure variation by the atmospheric pressure variation sensor 5 (step S62), and the in-vehicle data conversion unit 6 outputs the data. Based on this, the vehicle height fluctuation is calculated (step S63), and the in-vehicle data analysis unit 7 estimates the road traffic situation based on the data (step S64). Then, the in-vehicle control unit 4 adds flag information indicating temporary status data (update status data candidate 63) to the status data generated by the in-vehicle data analysis unit 7. And the vehicle-mounted control part 4 transmits the said update status data candidate 63 to the map data sensor 3 via the vehicle-mounted communication part 8 (step S65).

  Then, the center control unit 9 of the map data sensor 3 determines whether or not the acquired update status data candidate 63 matches the status data of the center map data 14 in the center map data storage unit 15 (step S66). If the center control unit 9 determines that they do not match (step S66; N), the situation data (DB correction situation data 64, sending situation data) is obtained by using the situation data of the center map data 14 as accurate data. Is transmitted to the in-vehicle navigation device 62 (step S67).

In this case, the in-vehicle controller 4 discards the update situation data candidate 63 and performs a process of storing the DB correction situation data in the situation database 53 (step S68). On the other hand, when the DB correction status data 64 is not transmitted to the in-vehicle navigation device 62, the in-vehicle control unit 4 performs a process of storing the update status data candidate 63 in the status database 53. And the vehicle-mounted control part 4 repeatedly performs the said process until a calibration period passes.
In this way, after the situation database 53 is adapted to the characteristics of the vehicle, the in-vehicle data analysis unit 7 operates, and more accurate and highly accurate situation data can be created.

  In the above embodiment, the route search is configured to be executed in the in-vehicle navigation device 2. However, for example, when a search unit is provided in the map data center 3 and a route search instruction is received from the user, Of course, the search unit in the map data center 3 may be configured to execute the search process using the latest map data. In addition, the map data search unit is configured to execute a search process in response to a route search instruction from the navigation device. For example, a search unit is provided in the in-vehicle navigation device, and the user issues a route search instruction. Of course, the vehicle-mounted navigation device may acquire the latest map data from the map data center and execute the search process.

(Seventh embodiment)
In the embodiment described above, a micro pressure sensor having a cantilever made of a thin film manufactured by a MEMS (MicroElectro Mechanical Systems) process can be used as the atmospheric pressure fluctuation sensor 5. The structure and signal processing method will be described below.

(Structure of pressure sensor)
FIG. 11 is a plan view showing a configuration of a pressure sensor 71 as the atmospheric pressure fluctuation sensor 5. FIG. 12 is a cross-sectional view of the pressure sensor 71 along the line AA shown in FIG.
The pressure sensor 71 is a sensor that detects pressure fluctuation in a predetermined frequency band (for example, 0.05 Hz to 10 kHz), and includes a sensor main body 73, an atmospheric pressure measurement cantilever 74, a lid portion 312, and a displacement measurement portion 75. And have.

  The sensor body 73 has a cavity 310 therein. The sensor body 73 divides the cavity 310 and is disposed on the first portion 73-1 made of resin, the first portion 73-1, and the silicon support layer 72a, the silicon oxide film, and the like. And a second portion 73-2 made of the oxide layer 72b.

  The atmospheric pressure measurement cantilever 74 can be formed, for example, by processing an SOI substrate 72 in which a silicon support layer 72a, an oxide layer 72b such as a silicon oxide film, and a silicon active layer 72c are thermally bonded.

The atmospheric pressure measurement cantilever 74 is formed of a silicon active layer 72c in the SOI substrate 72, and is formed by cutting out a gap 313 formed in a U-shape in plan view from the silicon active layer 72c on the flat plate. Here, the gap 313 (communication hole) is a gap formed between the atmospheric pressure measurement cantilever 74 and the inner wall of the sensor main body 73, and allows air inside and outside the cavity 310 to circulate.
Accordingly, the atmospheric pressure measurement cantilever 74 has a cantilever structure in which the base end portion 74a is a fixed end and the tip end portion 74b is a free end.

  The atmospheric pressure measurement cantilever 74 is disposed so as to surround the upper surface of the cavity 310 formed in the sensor main body 73. That is, the atmospheric pressure measurement cantilever 74 substantially closes the opening of the cavity 310.

  The atmospheric pressure measurement cantilever 74 is cantilevered so as to close the cavity 310 by being integrally fixed on the second portion 73-2 of the sensor body 73 via the base end portion 74a.

  Thereby, the pressure measuring cantilever 74 can be bent and deformed according to the pressure difference between the inside and the outside of the cavity 310 with the base end portion 74a as the center. Here, since the base end portion 74a of the atmospheric pressure measurement cantilever 74 is formed with a U-shaped through hole 315 in plan view, the atmospheric pressure measurement cantilever 74 is easily bent and deformed. However, the shape of the through hole 315 is not limited to the U-shape as long as it can easily be bent and deformed by the atmospheric pressure measurement cantilever 74.

  The lid 312 is disposed so as to surround the pressure measurement cantilever 74 through the gap 313 in plan view. The lid 312 is composed of a silicon active layer 72c. The lid 312 is disposed above the cavity 310.

The displacement measuring unit 75 (output unit) includes a piezoresistor 320 whose electric resistance value changes according to the amount of deflection (displacement amount) of the atmospheric pressure measurement cantilever 74 and a detection circuit 322 that extracts the change in electric resistance value. . As shown in FIG. 11, the piezoresistors 320 are arranged in pairs on both sides of the through hole 315 in the short direction of the atmospheric pressure measurement cantilever 74.
The pair of piezoresistors 320 are electrically connected to each other via a wiring portion 321 made of a conductive material.

  The overall shape including the wiring portion 321 and the piezoresistor 320 may be, for example, a U shape in plan view. The piezoresistor 320 is electrically connected to a detection circuit 322 that measures the displacement of the atmospheric pressure measurement cantilever 74 based on a change in the electric resistance value of the piezoresistor 320.

  In the displacement measuring unit 75 configured as described above, a current generated when a predetermined voltage is applied to the piezoresistor 320 through the detection circuit 322 wraps around the through-hole 315 so that the wiring unit 321 is connected from one piezoresistor 320. To the other piezoresistor 320.

  For this reason, the detection circuit 322 can take out the change in the electric resistance value of the piezoresistor 320 that changes in accordance with the displacement (deflection deformation) of the atmospheric pressure measurement cantilever 74 as an electrical output signal.

  Therefore, the displacement measuring unit 75 can measure the displacement of the atmospheric pressure measurement cantilever 74 based on the output signal (sensor output) of the detection circuit 322. Since the atmospheric pressure measurement cantilever 74 is deformed based on the differential pressure between the inside and the outside of the cavity 310, it is possible to take out the change in the atmospheric pressure outside the cavity 310 as an output signal.

  The piezoresistor 320 is formed by doping the silicon active layer 72c with a dopant (impurity) such as phosphorus by various methods such as an ion implantation method and a diffusion method.

In addition, the pair of piezoresistors 320 are configured to be electrically connected only by the wiring portion 321. For this reason, although not shown, the silicon active layer 72 c located around the atmospheric pressure measurement cantilever 74 is etched so that both the piezoresistors 320 do not conduct except at the wiring portion 321.
Further, a piezoelectric thin film may be used in place of the piezoresistor 320.

  In this case, an electromotive force is generated according to the stress applied to the base end portion 74b of the atmospheric pressure measurement cantilever 74, and the displacement of the atmospheric pressure measurement cantilever 74 can be detected by detecting the electromotive force.

(Pressure sensor operation)
Next, with reference to FIG. 13 and FIG. 14, the operation when the pressure sensor 71 described above detects a minute pressure fluctuation will be described.
FIG. 13 is a diagram schematically illustrating an example of the output of the pressure sensor 71. FIG. 13A is a diagram showing the change with time of the pressure inside and outside the cavity, and FIG. 13B is a diagram showing the change with time of the output of the pressure sensor 71.

  FIG. 14 is a cross-sectional view schematically showing an example of the operation of the pressure sensor 71. 14A shows a cross-sectional view of the pressure sensor in the initial state, and FIG. 14B shows a cross-sectional view of the pressure sensor when the pressure outside the cavity is higher than the internal pressure. C) shows a cross-sectional view of the pressure sensor when the pressure inside and outside the cavity returns to the same pressure. In FIG. 14, the detection circuit 322 constituting the pressure sensor 71 is not shown.

  First, as in period A shown in FIG. 13A, the difference between the pressure outside the cavity 310 (hereinafter, “external pressure Pout”) and the pressure inside the cavity 310 (hereinafter, “internal pressure Pin”) is zero. In this case, as shown in FIG. 14A, the pressure measuring cantilever 74 does not bend and deform.

  Here, as in the period B after time t1 shown in FIG. 13A, for example, when the external pressure Pout rises stepwise, a differential pressure is generated between the outside and the inside of the cavity 310. Therefore, FIG. ), The barometric pressure measuring cantilever 74 is bent and deformed toward the inside of the cavity 310.

  Then, distortion occurs in the piezoresistor 320 in accordance with the bending deformation of the atmospheric pressure measurement cantilever 74, and the electric resistance value changes, so that the output signal of the pressure sensor 71 increases as shown in FIG.

  Further, in the time after the increase of the external pressure Pout, the pressure transmission medium flows from the outside to the inside of the cavity 310 through the gap 313. For this reason, as shown in FIG. 13A, the internal pressure Pin rises with a response that is slower than the external pressure Pout and slower than the fluctuation of the external pressure Pout over time.

  As a result, the internal pressure Pin gradually approaches the external pressure Pout, so that the pressure between the outside and the inside of the cavity 310 is in an equilibrium state, and the bending of the atmospheric pressure measurement cantilever 74 gradually decreases, as shown in FIG. The output signal gradually decreases.

Then, when the internal pressure Pin becomes the same as the external pressure Pout as in the period C after time t2 shown in FIG. 13A, the bending deformation of the atmospheric pressure measuring cantilever 74 is eliminated as shown in FIG. 13C. To return to the original state. Furthermore, as shown in FIG. 13B, the output signal of the pressure sensor 71 also returns to zero.
Thus, by monitoring the fluctuation of the output signal based on the displacement of the atmospheric pressure measurement cantilever 74, the pressure fluctuation outside the cavity 310 can be detected.

  In particular, since the barometric pressure measuring cantilever 74 can be formed by a semiconductor process technology using the silicon active layer 72c of the SOI substrate 72, it is easy to make it thinner (for example, several tens to several hundreds nm) than a conventional piezoelectric element. Therefore, it is possible to detect minute pressure fluctuations with high accuracy.

  However, although the above-described output signal indicates an increase or decrease in the pressure of the outside air, it does not simply indicate a time variation (pressure gradient with respect to the time axis) of the pressure of the outside air. Specifically, the output signal increasing tendency in the period B1 in FIG. 13 indicates that the actual pressure to be measured (external pressure Pout) increases, but the output signal decreasing tendency in the period B2 is as described above. This is due to the increase of the internal pressure Pin due to the flow of the pressure transmission medium from the outside to the inside of the cavity 310, and suggests that the pressure of the actual measurement object will decrease even though it has not changed over time. . For this reason, even if a simple integration process or the like is performed on the output signal, it is impossible to grasp the time change of the pressure to be measured (time change of the external pressure). Further, the maximum value of the output signal shown in FIG. 13 at the boundary between the period B1 and the period B2 roughly indicates the pressure gradient with respect to the time axis, but is not necessarily the pressure gradient value. This is because the maximum value of the output signal changes depending on the time when the pressure fluctuation occurs. On the other hand, when the pressure of the outside air increases or decreases even slightly, an output signal corresponding to the direction in which the pressure changes (increase or decrease) can be obtained.

  As described above, the pressure sensor 71 can output an output signal only when the pressure of the outside air fluctuates. Furthermore, since the cantilever is thin, it can output even a slight pressure change. For this reason, as described above, when the output signal (pressure change information) of the pressure sensor 71 indicates an increase / decrease greater than or equal to a predetermined value, the vertical movement determination means 72 indicates that the altitude of the measurement object has decreased / increased Therefore, even if the measurement object goes up and down a step of several tens of centimeters, the vertical movement can be detected from the change in atmospheric pressure.

(Vertical movement amount / Calculation method)
Next, in the present embodiment using the pressure sensor 71, the procedure by which the in-vehicle data conversion unit 6 calculates the vertical movement amount of the measurement object from the output of the pressure sensor 71 will be described with reference to the flowchart of FIG.

  First, when an output signal is input from the pressure sensor 71 (step S701), the in-vehicle data conversion unit 6 stores N values of the output signal of the pressure sensor 71 in a storage device (not shown) every fixed time Δt. Store (step S702).

  Next, the in-vehicle data conversion unit 6 obtains differential pressures ΔP and N (ΔP (1 to N)) applied to the atmospheric pressure measurement cantilever corresponding to the output signal from the differential pressure database (step S703). Here, the differential pressure database measures in advance the output signal value of the pressure sensor 71 and the value of the differential pressure ΔP applied to the atmospheric pressure measurement cantilever 74 according to the output signal value for each output signal value. The relationship specified from the measurement result is stored as a database.

  Next, the in-vehicle data conversion unit 6 sets an initial value to the first internal pressure Pin (1) having the earliest time among the internal pressure Pin (i) (i = 1 to N, N: natural number of 2 or more). (Step S704). Here, the internal pressure Pin (1) according to the present embodiment is assumed to be atmospheric pressure on the assumption that it is used in the air. Next, the in-vehicle data conversion unit 6 adds Pin (i) and the differential pressure ΔP (i) to calculate the external pressure Pout (i) (step S705; differential pressure calculation step).

  Next, the in-vehicle data conversion unit 6 reads the flow rate Q (i) of the pressure transmission medium flowing into the cavity 310 from the flow rate database stored in the storage device using the differential pressure ΔP (i) (step S706). Here, the flow rate database is obtained by measuring the differential pressure ΔP and the flow rate Q corresponding to the magnitude of the differential pressure ΔP in advance for each differential pressure ΔP, and storing the relationship specified from the measurement result as a database. And

  Next, the in-vehicle data conversion unit 6 calculates the internal pressure Pin (i + 1) after Δt time from the flow rate Q (i) and the volume V of the cavity (step S707; measurement target pressure calculation step). Here, it is assumed that the fixed time Δt is very small, and the amount of change in the external pressure Pout for each Δt is very small, and the heat transfer and pressure loss are negligibly small. Therefore, the internal pressure Pin increases by the amount that the pressure transmission medium flows into the cavity 310. Therefore, the relationship among the flow rate Q (i), the volume V, the internal pressure Pin (i + 1) and the internal pressure Pin (i) can be expressed by the following equation (2).

Pin (i) × V = Pin (i + 1) × (V + Q (i) × Δt) (2)
For this reason, the in-vehicle data conversion unit 6 can obtain Pin (i + 1) after Δt time by the following equation (3).

Pin (i + 1) = V / (V + Q (i) × Δt) × Pin (i) (3)
Next, the in-vehicle data conversion unit 6 stores Pin (i + 1) obtained in step S707 and Pout (i) calculated in step S705 in the storage device constituting the in-vehicle data conversion unit 6 (step S708). ; Flow rate calculation step).

  Next, the in-vehicle data conversion unit 6 substitutes i + 1 for i (step S709), determines whether i exceeds N (step S710), and determines that i is equal to or less than N (step S710; N ), The processing of steps S705 to S709 is repeated (repetition processing step). At this time, the in-vehicle data conversion unit 6 updates the internal pressure Pin used in step S705 to Pin (i + 1) calculated in step S708 (internal pressure update step).

  Then, when it is determined that i is greater than N (step S710; Y), the in-vehicle data conversion unit 6 converts the vertical movement amount from the obtained N pieces of Pout (step S711). As a relational expression for obtaining an altitude change amount from the atmospheric pressure change amount, an expression (4) obtained by substituting Pout (i + 1) and Pout (i) into P1 and P2 of the expression (1) described in the first embodiment is used.

Δh = 18410.0 × log10 (Pout (i + 1) / Pout (i)) (4)
Here, Δh is the vertical movement amount [m], and Pout is the atmospheric pressure (absolute pressure) [hPa].
Thereby, the vehicle-mounted data conversion part 6 can obtain | require the up-and-down movement amount at the time of changing from the external pressure Pout (i) to Pout (i + 1).

  As described above, the in-vehicle data conversion unit 6 can accumulate N vertical movement amounts in the storage device every Δt time. This information indicates how far the measurement object has moved in the vertical direction during the N × Δt period.

Note that the Δt (predetermined time) may be configured so that the user can appropriately set the user interface unit (not shown) provided in the in-vehicle navigation device 2.
As described above, the in-vehicle data conversion unit 6 can measure the time course of the external pressure Pout and the amount of movement in the vertical direction from the output signal of the pressure sensor 71.

  The present invention enables a more accurate route search and information provision by allowing a map data system including an in-vehicle navigation device to include more detailed and accurate data.

DESCRIPTION OF SYMBOLS 1 Map data update system 2 Car navigation system 3 Map data center 4 Car control part 5 Pressure fluctuation sensor 6 Car data conversion part 7 Car data analysis part 8 Car communication part 9 Position information acquisition part 10 Map data 11 Map data storage part 12 Search Section 13 Center control section 14 Center map data 15 Center map data storage section 16 Traffic data 17 Traffic data storage section 18 Center communication section 19 Update situation data 20 Search situation data 21 Road data 22 Background data 23 Character data 24 Guidance data 31 Traffic jam data 32 Traffic regulation data 33 Time required data 34 Traffic obstacle data 35 Road situation data 41 Map data update system 42 Car-mounted navigation system 43 Vehicle speed acquisition unit 45 Update situation data 45
44 Situation database 61 Map data update system 62 In-vehicle navigation system 63 Situation data candidate 64 Situation data 71 Pressure sensor 72 SOI substrate 72a Silicon support layer 72b Oxide layer 72c such as silicon oxide film Silicon active layer 73 Sensor body 73-1 Sensor body 73-1 First part 73-2 Second part 74 of sensor main body Pressure measurement cantilever 74a Pressure measurement cantilever base end 74b Pressure measurement cantilever tip 75 Displacement measurement part 310 Cavity 312 Lid 313 Gap 315 Through hole 320 Piezo Resistance 321 Wiring unit 322 Detection circuit At Intensity threshold f1 First frequency threshold f2 Second week threshold S21 to S24 Operation steps S51 to S55 of the map data update system Operation steps S61 to S68 of the map data update system Operation steps of operational steps S701~S711 vertical movement amount calculation of the stem

Claims (17)

A navigation device that is configured to be communicable via a communication unit with a map data management server that manages map data, and is mounted on a vehicle,
An atmospheric pressure fluctuation sensor that detects fluctuations in ambient atmospheric pressure and outputs it as atmospheric pressure fluctuation data;
An in-vehicle data conversion unit that calculates a height fluctuation amount along the gravitational acceleration direction of the vehicle based on the atmospheric pressure fluctuation data output by the atmospheric pressure fluctuation sensor;
An in-vehicle data analysis unit that generates situation data related to estimation of road traffic conditions from the amount of height fluctuation calculated by the in-vehicle data conversion unit;
A situation data transmission unit that transmits the situation data generated by the in-vehicle data analysis unit to the map data management server via the communication unit;
A navigation device comprising:   The in-vehicle data analysis unit frequency-analyzes the height variation data, determines an uneven state of the road surface from the first frequency among the analyzed frequency components, and generates the situation data based on the determined uneven state The navigation device according to claim 1.   The vehicle data analysis unit determines a road surface inclination state from the second frequency among the analyzed frequency components, and generates the situation data based on the determined inclination state. The navigation device described in 1.   The in-vehicle data analysis unit determines a congestion situation of a road from a third frequency component different from the first and second frequency components among the analyzed frequency components, and the situation data based on the determined congestion situation The navigation device according to claim 3, wherein the navigation device is generated.   The navigation apparatus according to claim 4, wherein the road congestion state determined by the in-vehicle data analysis unit is a congestion state related to a lane adjacent to or opposite to a lane in which the vehicle travels. A vehicle speed transmission unit that acquires speed information related to the speed of the vehicle and transmits the acquired speed information to the in-vehicle data analysis unit,
The vehicle data analysis unit calculates a three-dimensional trajectory of the vehicle based on the height variation and the speed information, and generates the situation data based on the calculated trajectory. The navigation device according to 1. A situation database unit that stores the height fluctuation amount and situation data corresponding to the height fluctuation amount for each height fluctuation amount,
The navigation device according to claim 1, wherein the in-vehicle data analysis unit extracts situation data corresponding to a height fluctuation amount calculated by the in-vehicle data conversion unit from the situation database unit. Provided with a search unit that searches for the optimum route from the departure point to the arrival point under the given route search conditions,
The navigation device according to claim 1, wherein the search unit searches for the optimum route using the situation data. A time data generation unit that generates time data related to the time when the atmospheric pressure fluctuation sensor detects the atmospheric pressure fluctuation,
The navigation apparatus according to claim 1, wherein the situation data transmission unit transmits the time data together with the situation data to a map data management server. The atmospheric pressure fluctuation sensor
A cavity having a predetermined volume;
A communication hole through which the pressure transmission medium for transmitting the atmospheric pressure flows into and out of the cavity;
An output unit that outputs atmospheric pressure fluctuation data relating to a differential pressure between an internal pressure that corresponds to a reference pressure that varies according to atmospheric pressure fluctuation and represents the internal pressure of the cavity, and the ambient pressure;
The navigation apparatus according to claim 1, further comprising: The in-vehicle data converter is
A differential pressure calculation unit for obtaining a differential pressure between the internal pressure and the ambient atmospheric pressure based on the atmospheric pressure fluctuation data;
A pressure calculating unit that calculates the ambient atmospheric pressure based on the set value of the internal pressure and the differential pressure calculated by the differential pressure calculating unit;
Based on the differential pressure calculated by the differential pressure calculation unit, a flow rate calculation unit that calculates a flow rate per predetermined time of the pressure transmission medium flowing inside and outside the cavity;
Based on the flow rate calculated by the flow rate calculation unit and the volume of the cavity, the internal pressure after a predetermined time is calculated, and the set value of the internal pressure used in the pressure calculation unit is updated with the calculated internal pressure. An internal pressure update unit
The navigation device according to claim 10, comprising: The atmospheric pressure variation sensor is provided so as to close an opening surface of the cavity excluding the communication hole, and has a cantilever that bends and deforms according to the differential pressure,
The navigation device according to claim 10 or 11, wherein the output unit outputs atmospheric pressure fluctuation data corresponding to a bending deformation amount of the cantilever. A map data update system comprising the navigation device according to any one of claims 1 to 12 and the map data management server,
The map data management server
A map data update system comprising a map data creation unit that creates new map data based on status data received from the navigation device. The navigation device
It has a position data acquisition unit that acquires current position data representing the current position,
The situation data includes estimation information relating to the height fluctuation of the road at the current position acquired by the position data acquisition unit,
The map data management server
The map data includes predetermined position data at a predetermined position, and information regarding a change in the height of the road near the predetermined position,
When the situation data is received from the navigation device, if the distance between the current position and the predetermined position is smaller than a predetermined value, the estimation information regarding the height fluctuation of the situation data and the height of the map data A height variation determination unit that determines whether or not the information about the variation in height matches,
A position data transmission unit that transmits the predetermined position data to the navigation device when it is determined by the height variation determination unit to match,
The navigation device
The map data update system according to claim 13, wherein the position data acquisition unit corrects current position data with the predetermined position data transmitted by the position data transmission unit. The map data creation unit of the map data management server includes:
The map data update system according to claim 13, wherein a validity period of the situation data is set, and the situation data is discarded when the validity period is exceeded. A map data update system comprising the navigation device according to claim 7 and the map data management server,
The navigation device
A calibration unit for creating situation data stored in the situation database unit;
When the calibration unit determines that a predetermined time has passed since the navigation device is mounted on the vehicle, and the progress determination unit determines that the progress determination unit has not elapsed, A provisional situation data transmission unit that causes the in-vehicle data analysis unit to generate the situation data and transmits the situation data as provisional situation data to the map data management server via the communication unit;
The map data management server
A map data storage unit for storing map data associated with situation data in advance;
A match determination unit that determines whether or not the temporary status data transmitted by the temporary status data transmission unit matches the status data corresponding to the map data stored in the map data storage unit;
A situation data sending unit for sending that sends situation data corresponding to the map data to the navigation device as situation data for sending when it is judged by the match judging unit that they do not match;
With
The navigation device
The calibration unit includes a status data storage unit that stores the status data for sending in the status database unit as status data when the status data for sending is transmitted by the status data transmitting unit for sending. Map data update system. A map data update system including the navigation device according to claim 9 and the map data management server,
The map data management server
Connected to a plurality of the navigation devices,
A map data update system comprising: a map data creation unit that creates new map data based on situation data corresponding to the latest time data among the situation data transmitted from the plurality of navigation devices.

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