JP2005149358A - Probe car system and device using beacon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a probe car system in which use of probe information can be sufficiently confirmed not from a technical view but also from an economical view by reducing the collection cost of probe information. <P>SOLUTION: The probe car system comprises a probe car onboard machine 20 having information communicating function with a beacon 10, the machine generating and transmitting transmitting information including encoded data of traveling trace data, encoded data of measurement data measured during traveling and a destination code to the beacon 10; the beacon 10 for transferring the transmitting information received from the probe car onboard machine 20; a delivery center 30 for delivering the traveling trace data and measurement data transmitted through the beacon 10 to a destination; and an agent 42 for decoding the delivered traveling trace data and measurement data to generate information for information providing service. The probe information can be collected at low cost through the beacon 10. Since this probe information is compression-encoded, it can be transmitted to a regulated frame for uploading a signal to the beacon 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a probe car system that collects information using a beacon and a device used in the system, and realizes the generation of sophisticated traffic information and the like by efficiently using the beacon.

Currently, VICS (Road Traffic Information Communication System), which provides traffic information providing services, provides information to car navigation in-vehicle devices using optical beacons, radio beacons and FM multiplex broadcasting. Among these, the optical beacon has a bidirectional communication function with the in-vehicle device, and not only transmits traffic information to the in-vehicle device but also can receive information transmitted from the in-vehicle device.
In the future, the implementation of a bidirectional communication function is also being considered for radio beacons.

  FIG. 22 shows how information is uploaded from the in-vehicle device to the optical beacon 10. Information is transmitted in units of frames. FIG. 22A shows the frame configuration. One frame consists of 69 bytes, 10 bytes are allocated to the header part, and travel time measurement information between beacons (information for measuring the time required for a vehicle equipped with an onboard device to pass between optical beacons) 5 bytes are allocated for transmission. The remaining 54 bytes are loaded with the upload information necessary for the public vehicle priority system that ensures the punctuality of buses and the vehicle operation management system that efficiently operates by grasping the driving positions of buses, taxis, trucks, etc. However, in general car navigation on-vehicle devices, it is a filler and is not used. In addition, uploading can transmit signals of up to 4 frames.

  The optical beacon 10 installed on the road is under the jurisdiction of the traffic manager, and the information sent from the in-vehicle device to the optical beacon 10 is sent to the traffic manager system 11 of each prefecture as shown in FIG. It is transmitted and used to generate traffic information and traffic control information. In the future, when road managers convert radio beacons to two-way communication, the situation will be similar to that of optical beacons due to differences in data structure.

  In addition, as a new form of collecting traffic information, a probe car system in which a traveling vehicle serves as a sensor (probe) and collects information such as speed measured by the traveling vehicle at a center is currently being studied. Probe information collected at the center is used to generate traffic information and traffic control information. Unlike the ultrasonic sensors and AVI sensors that are fixed on the road, the probe car can collect data in real time from a very wide range, so by analyzing the probe information, highly accurate traffic information and traffic control information Can be generated.

In the following Patent Document 1, the center specifies a probe information collection area, and a probe car onboard device of a vehicle traveling in this area measures and accumulates data such as a travel position and a travel speed every unit time. There has been proposed a probe car system that transmits accumulated data to a center by a cellular phone at regular intervals.
JP 2002-269669 A

  However, it is clear from recent studies that probe information is useful for generating traffic information and traffic control information. However, if an effective number of information cannot be actually collected, it is attributed to a “pushpin”. The bottleneck in collecting probe information is the communication fee required for information transmission. For example, if the monthly communication fee per in-vehicle device reaches several thousand yen due to the use of a mobile phone, the probe is too expensive. It is difficult to establish a car system.

  The present invention solves these conventional problems, provides a probe car system that reduces the cost of collecting probe information, supports the use of probe information not only technically, but also economically, and The object is to provide a device for use in the system.

In the present invention, the encoded traveling locus data having the function of transmitting information to the beacon and encoding the traveling locus data of the mounted vehicle, and the encoded measurement data encoding the measurement data measured during the traveling of the vehicle. And a transmission device that generates transmission information including a code indicating a destination and transmits the transmission information to a beacon, a beacon that has an information reception function from the transmission device and transfers transmission information received from the transmission device, and a beacon A distribution center that distributes the encoded travel locus data and encoded measurement data sent to those destinations, and decodes the encoded travel locus data and encoded measurement data distributed from the distribution center for use in an information providing service. The probe car system is composed of information users who generate the information.
In this probe car system, probe information consisting of travel locus data and measurement data can be collected through a beacon at low cost. Moreover, since this probe information is compression-encoded, it can be transmitted on a prescribed frame for uploading a signal to a beacon.

Further, the transmission device of the probe car system transmits the transmission information including identification information that contributes to the measurement of the travel time between the beacons of the vehicle.
In this probe car system, a transmitting device (probe on-vehicle device) that sends probe information to an information user (a third party different from the beacon administrator) via an optical beacon is connected between beacons required by each administrator system. Travel time measurement information will be sent together. Therefore, when the use of the existing optical beacon is opened to the private sector and this probe car system is realized, the information collection capability of each administrator system increases.

The information user of the probe car system provides at least part of the information providing service information to the administrator system that measures the travel time between the beacons of the vehicle based on the identification information.
A part of the high value-added traffic information generated by the information user based on the probe information is provided to each manager system as a price for using the optical beacon. Each administrator system can use the provided information when generating traffic information.

The transmitter of this probe car system (probe car on-vehicle device) converts the travel locus data into statistically biased data, then sets the data obtained by variable length coding as encoded travel locus data, The measurement data is subjected to discrete wavelet transform, and only data that can reproduce the scaling coefficient of a predetermined order is selected as encoded measurement data.
Therefore, the amount of probe information data is greatly reduced.

Moreover, the transmission device (probe vehicle mounted device) of the probe car system transmits the transmission information including the option information of the destination information user.
For example, as this optional information, information related to maintenance of the vehicle on which the probe car on-vehicle device is mounted is transmitted.
Examples of the information related to maintenance include travel distance and travel time, information on abnormality detection sensors mounted on the vehicle, and self-diagnosis information on each control device of the vehicle.
The business operator to which the maintenance information is distributed can perform a maintenance service suitable for time.

The probe car system transmission device (probe car on-vehicle device) has a communication means for beacons and a wireless communication means for information users, and switches communication means for transmitting transmission information according to the situation. .
Therefore, even when it is necessary to send information in real time or when traveling in an area where there is no beacon, the information can be transmitted to the information user through the wireless communication means.

  This transmission device accumulates the encoded travel locus data and the encoded measurement data when the transmission information cannot be transmitted even after a predetermined time has elapsed from the measurement time of the measurement data, and when the occurrence of an emergency is detected. When the buffer reserve capacity decreases below a predetermined amount, when the travel distance from the point where the transmission information is transmitted reaches a certain distance, when the vehicle stops or shifts to the stop, or when the vehicle is a beacon When entering a non-installation area, the transmission information is transmitted using wireless communication means.

  The on-vehicle apparatus of the present invention includes a vehicle position measuring unit that measures a traveling locus of a traveling vehicle, a measuring unit that measures a traveling state of the traveling vehicle, and a coding that encodes the traveling locus data and the measurement data. A processing means, and a communication means for transmitting transmission information including encoded data encoded by the encoding processing means and a code indicating a destination to a beacon, and used as a transmitter of the probe car system of the present invention Can do.

  In the probe car system of the present invention, probe information is collected using beacons, so that the cost of communication charges can be reduced, and the economics of the business using the probe information is ensured. In addition, since the probe information is compressed and encoded, it is technically possible to upload the information to a beacon by placing it on a specified frame while the vehicle passes through the communication area of the beacon.

(First embodiment)
In the probe car system according to the first embodiment of the present invention, it is assumed that the filler part of the frame that sends information from the in-vehicle device to the optical beacon is opened to a third party other than the administrator who installed the beacon.
In that case, as shown in FIG. 2, the filler for 54 bytes of the frame 60 consisting of 69 bytes becomes a private open part 62 that can be used by a third party (for example, private sector). Further, the frame 60 is obliged to include a 10-byte header section 611 and 5-byte inter-beacon travel time measurement information 612 as the defining section 61.

  In addition, a signal of up to 4 frames can be sent from the in-vehicle device to the optical beacon, but each frame after the second frame includes only the header portion 611 in the defining portion 61, and the remaining 59 bytes of the frame are It becomes a private open department. Therefore, in the case where a signal of 4 frames is sent from the in-vehicle device to the optical beacon, a total of 231 (= 54 + 59 × 3) bytes of private open parts can be secured.

In this probe car system, a private information collection provider such as a third party other than the administrator deploys his own probe car and collects probe information measured by the on-board device of the probe car. At the time of collection, an optical beacon managed by the administrator system is used. A private information collection provider generates advanced traffic information from the collected probe information, provides traffic information provision services to users, and uses part of the generated traffic information as media rent using optical beacons. Provide to each administrator system.
FIG. 1 schematically shows this probe car system. This system includes a probe car 20 deployed by a private information collection provider, an optical beacon 10 that receives a signal including information on the defining unit 61 and the private opening unit 62 from an in-vehicle device of the probe car 20, and an optical beacon 10 that receives the signal. Included in each of the administrator systems 11 to which the information is transmitted, the uplink collection / distribution center 30 that collects the information of the private open parts 62 from each administrator system 11 and distributes the information to the private information collection provider, and the private open part 62 Private information collection providers 41 and 42 that edit and analyze the probe information generated to generate traffic information, and a user 50 that receives a traffic information providing service from the private information collection providers 41 and 42.

  The probe car 20 is, for example, a taxi or a transport truck contracted by private information collection providers 41 and 42, and is equipped with a probe car on-vehicle device having a bidirectional communication function to the optical beacon 10 and a measurement function such as speed. doing.

  This probe car in-vehicle device measures vehicle speed and the like and accumulates measurement data every time a certain time elapses (or every time the probe car 20 travels a certain distance), and the latitude / longitude of the current position. To store latitude / longitude data. When the probe car 20 passes under the optical beacon 10, the measurement data and latitude / longitude data accumulated so far are compression-encoded, and as shown in FIG. The code (or address) of the information collection provider A (42) is included in the private open section 62 of the signal uploaded to the optical beacon 10, and the signal specifying section 61 includes a header and travel time measurement between beacons. It transmits including the identification information of the probe car 20 used for information.

The optical beacon 10 transmits a reception signal to each administrator system 11. Each manager system 11 takes out the travel time measurement information between beacons (vehicle identification information) of the default unit 61 from the received signal, and determines the interval between beacons from the time difference between the adjacent optical beacons when the same vehicle identification information is received. Calculate travel time. In addition, the information of the private open section 62 in the received signal is transferred to the uplink collection / distribution center 30 without looking at the contents.
The uplink collection / distribution center 30 is the only organization in the whole country, and information on the private open section 62 is sent from each manager system 11. Upon receiving this information, the uplink collection / distribution center 30 identifies the transfer destination of the private open section 62 from the transmission destination code included therein, and transmits it to the corresponding private information collection provider A (42).

The private information collection provider A (42) decodes the received information of the private open section 62, obtains the travel locus of the probe car from the array of latitude / longitude data, and obtains the traffic situation on the travel locus from the measurement data. .
Private information collection provider A (42) generates highly accurate traffic information (current information and forecast information) by statistically analyzing a large number of probe information collected in this way and comparing it with past traffic conditions. can do. The private information collection provider A (42) provides the generated traffic information to the user 50, and provides a part of the generated traffic information to each administrator system 11 as a consideration for using the optical beacon 10.

  Thus, in this probe car system, it is possible to effectively utilize existing infrastructure and reduce the cost of collecting probe information. A private information collection provider using this system can generate high-value-added traffic information from a large number of probe information collected at low cost, and can develop a business of traffic information providing service. On the other hand, each administrator system will be able to collect more information on the default part because the number of in-vehicle devices that upload information through optical beacons will increase, and the information provided by private information collection providers will be used for traffic information. Can be used for generation.

The configuration of the probe car in-vehicle device and the procedure for generating probe information in the probe car in-vehicle device will be described later.
Although the case where an optical beacon is used for collecting probe information has been described here, a new radio wave beacon having a bidirectional communication function that is currently being considered can be used in place of the optical beacon.

(Second Embodiment)
In the second embodiment of the present invention, a probe car system that collects probe information using a beacon jointly installed by a private information collection provider will be described.
In this system, as shown in FIG. 4, the probe car 20 contracted with each private information collection provider 41, 42 uploads probe information through the beacon 10 jointly installed by the private information collection provider. The probe information received by the beacon 10 is transmitted to the uplink collection / distribution center 301, and the uplink collection / distribution center 301 distributes the probe information to the destination private information collection providers 41 and 42, and the data amount thereof. Charge the private information collection provider according to the communication fee.

FIG. 5 shows the data structure of the probe information transmitted from the probe car onboard device to the beacon. This frame includes a header 621, measurement information 622 that is included in all probe information, a transmission destination code (operator code or address) 623 indicating a destination private information collection provider, and a private information collection provider. Probe information 624 that is uniquely collected is included. The number of bytes in one frame is 69 bytes as in the first embodiment.
FIG. 6 shows functional blocks of the probe car in-vehicle device 70, the beacon 10 and the uplink collection / distribution center 301 that constitute this system.

The probe car in-vehicle device 70 includes a sensor information collecting unit 77 that collects measurement information such as a sensor A86 that detects a speed, a sensor B87 that detects a power output, a sensor 88 that detects fuel consumption, and a sensor that detects a door open / close signal. The measurement information collected by the sensor information collecting unit 77 is valid or invalid based on the detection results of the sensor Y84 for detecting X83, the hazard signal, the sensor Z85 for detecting the signal indicating the seat belt, and the like. Measurement information validity / invalidity determination unit 76 for determining whether the vehicle position is determined by using the GPS information received by the GPS antenna 81 and the information of the gyro 82, the vehicle position determination unit 73, A traveling locus measurement information accumulating unit 75 that accumulates measurement information of the sensors A, B, and C, and probe information that compresses and encodes the accumulated traveling locus data and measurement data. The encoding processing unit 72, and a data destination managing unit 74 which manages the destination code of the probe information and probe information transmitting unit 71 for transmitting the probe information transmission destination code is assigned to the beacon 10. The configuration of the probe car in-vehicle device 70 is the same in the first embodiment.
The beacon 10 includes a probe information receiving unit 102 that receives probe information from the in-vehicle device 70, and a center device communication unit 101 that transmits the received probe information to the uplink collection / distribution center 301.

  Further, the uplink collection / distribution center 301 includes a beacon communication unit 302 that receives probe information from the beacon 10, a provider code extraction unit 303 that extracts a sender code from the received information, and a private sector of a transmission destination from the sender code. A transmission destination identification unit 304 that identifies an information collection provider, a communication control unit 306 that transmits probe information to the carrier communication devices 411, 421, and 431 as transmission destinations via the network 40, and a private sector depending on the amount of communication A communication fee billing unit 305 that charges a communication fee to the information collection provider.

In the probe car in-vehicle device 70, for example, in units of one second, the own vehicle position determination unit 73 detects the current position that is the basis of the travel locus data, and the sensor information collection unit 77 measures measurement data such as speed, power output, and fuel consumption. To collect. The measurement information valid / invalid determination unit 76 determines that the probe car is not running when the door is open, the hazard signal is lit, or the seat belt is not worn. Invalidate measurement data. The travel locus data and valid measurement data are stored in the travel locus measurement information storage unit 75.
The probe information encoding processing unit 72 performs variable length encoding on the traveling locus data accumulated in the traveling locus measurement information accumulation unit 75 and performs discrete wavelet transform (DWT) on the measurement data. This variable length coding and DWT will be described later.

When the probe car 20 enters the communication range of the beacon 10, the probe information encoding processing unit 72 receives the travel locus data and measurement data encoded so far, and the sender code acquired from the information transmission destination management unit 74. The probe information transmission unit 71 transmits the probe information to the beacon 10.
This probe information is sent from the beacon 10 to the uplink collection / distribution center 301. The flowchart of FIG. 7 shows the operation procedure of the uplink collection / distribution center 301.

When the information uploaded from the beacon 10 is received (step 1), the provider code extraction unit 303 extracts the transmission destination code included in this information (step 2), and determines whether or not the transmission destination code is valid. (Step 3). When the transmission destination code is valid, the transmission destination specifying unit 304 specifies the transfer destination operator from the transmission destination code (step 4), and the communication control unit 306 transmits the probe information to the operator. (Step 5). The communication fee billing unit 305 accumulates the communication fee of the operator according to the amount of probe information transmitted (or the amount received from the beacon).
In this way, in this probe car system, probe information is collected using beacons jointly installed by the private sector, so that the probe information collection cost can be reduced compared to the case where the probe information is transmitted by a mobile phone or the like. Can do.

  Next, variable-length encoding of travel locus data and DWT of measurement data performed by the probe information encoding processing unit 72 of the probe car on-vehicle device 70 will be described. The processing of the probe car on-vehicle device 70 is the same in the first embodiment.

<Variable-length encoding of travel locus data>
As shown in FIG. 8 (a), the nodes Pj-1, Pj,... Are resampled at a certain distance L (for example, 200 m) on the traveling locus of the probe car 20, and the position data of each node is displayed as an adjacent node. The angle of deviation θ from If the measurement start point or end point is used as a reference point, and the position of the reference point is specified by latitude and longitude, the position of each node can be specified only by the declination θ by making L constant. Further, as shown in FIG. 8B, the deflection angle θj of the node of interest is the predicted deflection angle value Sj (statistics) of the node predicted using the deflection angles θj-1 and θj-2 of the previous nodes. Predicted value: For example, it can be expressed by a difference Δθj between (θj−1 + θj−2) / 2) and the deviation angle θj.

The probe car 20 traveling in an urban area where there are many straight roads represents the node position by the deflection angle θ. By doing so, the position data of the node is concentrated around 0 as shown in FIG. Further, the probe car 20 that travels in a mountainous area where there are many curved roads represents the node position as a statistical prediction difference value Δθ. By doing so, the position data of the node is concentrated around 0 as shown in FIG.
After giving statistical bias to the position data of the nodes in this way, as shown in FIG. 9A, a code that assigns a small code to data with high appearance frequency and assigns a large code to data with low appearance frequency Using the table, the node position data is variable-length encoded to reduce the amount of data. Further, the position data of the nodes are arranged in order, and continuous length compression is performed on consecutive 0s included in the array using the run-length code table shown in FIG. 9B, thereby further reducing the data amount.

The private information collection provider that has received the encoded data performs the reverse process to restore the position data of each node, and specifies the travel locus of the probe car on the digital map.
FIG. 10 shows a map of an area where a probe car field test was conducted. The probe car that traveled from the point (1) to the point (2) on the map measured the position at 61 locations while traveling, but the total data amount of the latitude / longitude data was 488 bytes. By applying the above-described variable length encoding to the travel locus data, the data amount was compressed to about 3/12 bytes, which is about 1/12. In addition, A, B, C, and D on the map indicate installation positions of existing optical beacons.

<Measured data DWT>
Measurement data such as speed and fuel consumption is subjected to discrete wavelet transform (DWT) to reduce the data amount. The data subjected to DWT is restored by performing inverse discrete wavelet transform (IDWT).
Here, DWT and IDWT will be described.

  A general formula of the wavelet transform is shown in FIG. A wavelet is an operation (scale conversion) for multiplying a function Ψ (t), which is called a basic wavelet only in a limited range in terms of time and frequency, by a on the time axis, or b in terms of time. This is a set of functions such as (Equation 3) that can be obtained by performing an operation (shift conversion) of shifting only horizontally. Using this function, the frequency and time components of the signals corresponding to the parameters a and b can be extracted, and this operation is called wavelet transform.

Wavelet transformation includes continuous wavelet transformation and discrete wavelet transformation (DWT). The forward transformation of the continuous wavelet transform is shown in (Equation 1) and the inverse transformation is shown in (Equation 2). By setting the real numbers a and b as a = 2 ^j and b = 2 ^j k (j> 0), the forward transformation of the discrete wavelet transformation (DWT) is as shown in (Equation 5), and the inverse transformation (IDWT). Is expressed as (Equation 6).

  The DWT can be realized by a filter circuit that recursively divides a low frequency band, and the IDWT can be realized by a filter circuit that repeats synthesis reverse to that at the time of division. FIG. 12A shows a DWT filter circuit. This DWT circuit is configured by a cascade connection of a plurality of circuits 191, 192, 193 including a low-pass filter 181, a high-pass filter 182, and a decimation circuit 183 that thins out a signal to 1/2. After the high-frequency component of the signal input to the signal passes through the high-pass filter 182, it is thinned out by a thinning circuit 183 and output, and the low-frequency component passes through the low-pass filter 181. The data is thinned out by the thinning circuit 183 and input to the next circuit 192. Similarly, in the circuit 192, the high frequency component is thinned out and output, and the low frequency component is thinned out and then input to the next circuit 193, where it is similarly divided into a high frequency component and a low frequency component. .

  FIG. 13A shows signals decomposed by the respective circuits 191, 192, and 193 of the DWT circuit. The input signal f (t) (≡Sk (0); the characters in parentheses indicate the degree. ) Is divided by the circuit 191 into a signal Wk (1) that has passed through the high-pass filter 182 and a signal Sk (1) that has passed through the low-pass filter 181, and the signal Sk (1) is divided into the next circuit 192. Is divided into a signal Wk (2) that has passed through the high-pass filter 182 and a signal Sk (2) that has passed through the low-pass filter 181, and the signal Sk (2) is The signal Wk (3) that has passed through the filter 182 and the signal Sk (3) that has passed through the low-pass filter 181 are divided. This S (t) is called a scaling coefficient, and W (t) is called a wavelet coefficient.

The following (Equation 8) and (Equation 9) show DWT conversion equations used in the embodiment of the present invention.
Step 1: s (t) = (f (2t) + f (2t + 1) +1) / 2 (Equation 8)
Step 2: w (t) = f (2t)-f (2t + 1) (Equation 9)
In the first-order forward transformation, the discrete value of the original data is set to f (t), and the transformation to the first-order scaling coefficient and the first-order wavelet coefficient is performed by (Equation 8) and (Equation 9). In the n-th order forward conversion, the (n-1) -th scaling coefficient is set to f (t), and the conversion to the n-th order scaling coefficient and wavelet coefficient is performed by (Equation 8) and (Equation 9). Is called.

  The scaling coefficient indicates information obtained by smoothing (averaging) the input data. The first-order scaling coefficient indicates two of the original data, and the n-th scaling coefficient is (n−1). ) Two of the following scaling factors are shown smoothed. The wavelet coefficient indicates difference information for restoring the original data from the scaling coefficient.

  FIG. 12B shows an IDWT filter circuit. The IDWT circuit includes an interpolation circuit 186 that interpolates the signal twice, a low-pass filter 184, a high-pass filter 185, an adder 187 that adds the outputs of the low-pass filter 184 and the high-pass filter 185, and A plurality of circuits 194, 195, and 196 having a low-frequency component and a high-frequency component signal input to the circuit 194 are interpolated twice, added, and input to the next circuit 195. The circuit 195 adds the high frequency component, and the next circuit 196 adds the high frequency component and outputs the result.

  FIG. 13B shows signals reconstructed by the respective circuits 194, 195, and 196 of the IDWT circuit. In the circuit 194, the scaling coefficient Sk (3) and the wavelet coefficient Wk (3) are added. The scaling coefficient Sk (2) is generated, and in the next circuit 195, the scaling coefficient Sk (2) and the wavelet coefficient Wk (2) are added to generate the scaling coefficient Sk (1). Then, the scaling coefficient Sk (1) and the wavelet coefficient Wk (1) are added to generate Sk (0) (≡f (t)).

The following (Equation 10) and (Equation 11) show conversion formulas of IDWT used in the embodiment of the present invention.
Step 1: f (2t) = s (t) + (w (t) / 2) (Equation 10)
Step 2: f (2t + 1) = s (t)-{(w (t) +1) / 2} (Equation 11)

In the n-th order inverse transformation, the signal f (t) transformed by the (n + 1) -th order IDWT is used as a scaling coefficient, and this f (t) (= s (t)) and a given wavelet coefficient w (t ) And (Equation 10) and (Equation 11) are used for conversion.
The data sequence of the original data (discrete values) can be converted into a data sequence of scaling coefficients and wavelet coefficients using (Equation 8) and (Equation 9). , (Equation 10) and (Equation 11) can be used to restore the original data string of discrete values.

FIG. 14 shows a specific example in which a data string of scaling coefficients and wavelet coefficients is generated by applying DWT to the measurement data of FIG.
First, in order to reduce the amount of transmission data, the numerical value of the measurement data (FIG. 14A) is expressed as a difference from the average value (= 9) as shown in FIG. Make it apparently small.

  First to fourth order DWT is applied to this data. The DWT coefficients (scaling coefficient, wavelet coefficient) of each order obtained by DWT are stored in a storage area divided into numbers corresponding to the number of original data, as shown in FIG. Here, serial numbers from 0 to 15 are assigned to the storage areas (the storage area 16 is a non-target area). For the sake of explanation, the n-th order scaling coefficient stored in the storage area p is represented as Sn (p), and the wavelet coefficient is represented as Wn (p).

The first-order DWT coefficient is obtained as follows.
S1 (0): The first original data “5” and the second original data “6” are obtained by substituting into (Equation 8).
W1 (1): The first original data “5” and the second original data “6” are substituted into (Equation 9) and obtained.
S1 (2): The third original data “5” and the fourth original data “4” are substituted into (Equation 8) and obtained.
W1 (3): The third original data “5” and the fourth original data “4” are obtained by substituting into (Equation 9).
The same applies hereinafter.

The secondary DWT coefficient is obtained as follows.
S2 (0); S1 (0) and S1 (2) are calculated by substituting into (Equation 8).
W2 (2); S1 (0) and S1 (2) are substituted into (Equation 9) and obtained.
S2 (4); S1 (4) and S1 (6) are substituted into (Equation 8) and obtained.
W2 (6); S1 (4) and S1 (6) are substituted into (Equation 9) and obtained.
The same applies hereinafter.

The third-order DWT coefficient is obtained as follows.
S3 (0); S2 (0) and S2 (4) are substituted into (Equation 8) to obtain.
W3 (4); S2 (0) and S2 (4) are calculated by substituting into (Equation 9).
S3 (8); S2 (8) and S2 (12) are substituted into (Equation 8) and obtained.
W3 (12); S2 (8) and S2 (12) are calculated by substituting into (Equation 9).

The fourth-order DWT coefficient is obtained as follows.
S4 (0); S3 (0) and S3 (8) are substituted into (Equation 8) and obtained.
W4 (4); S3 (0) and S3 (8) are substituted into (Equation 9) and obtained.
FIG. 14D shows the value of the DWT coefficient of each storage area obtained when performing DWT up to the fourth order in this way.
As described above, the data string of the original data in FIG. 14A is subjected to DWT up to the fourth order, so that one fourth-order scaling coefficient S4, one fourth-order wavelet coefficient W4, and two pieces of data are obtained. It is converted into a third-order wavelet coefficient, four second-order wavelet coefficients, and eight wavelet coefficients.

  Conversely, given one quartic scaling coefficient S4 and one quaternary wavelet coefficient W4, two third order scaling coefficients S3 can be restored by the IDWT, If the third-order wavelet coefficient W3 is added, four secondary scaling coefficients S2 can be restored by the IDWT, and if four second-order wavelet coefficients W2 are added thereto, the IDWT is 8 The number of primary scaling factors S1 can be restored.

  If eight primary wavelet coefficients W1 are additionally provided to these DWT coefficients, the original data in FIG. 14A can be restored to the original (that is, reversibly) by IDWT. (However, if a data shift from FIG. 14 (a) to FIG. 14 (b) is performed during DWT, the reverse shift is performed on the result of IDWT).

  However, even when the primary wavelet coefficient W1 cannot be obtained (that is, even with irreversible transformation), the reproduced primary scaling coefficient S1 has half the number of original data, and the position of the original data is continuous. Since the two values are averaged (in other words, the original data is represented by 1/2 position resolution), it is possible to grasp the tendency of the original data from the primary scaling coefficient S1. It is. That is, the tendency of the original data can be grasped with half of the original data. When the number of original data is large, the tendency of the original data can be grasped by higher order scaling factors such as the secondary scaling factor S2 and the tertiary scaling factor S3.

  FIG. 15A shows speed data measured at 61 points while the probe car that traveled from the point (1) to the point (2) on the map shown in FIG. Is displayed as a graph with the distance from the reference point. The total amount of speed data required to represent this speed transition is 332 bytes. FIG. 15B is a graph showing the transition of the speed with a position resolution of 1/8 of FIG. 15A using DWT on the speed data (original data) and using a cubic scaling coefficient. The total data amount of this third-order scaling coefficient is 43 bytes. FIG. 15C is a graph showing a change in speed with a position resolution of 1/16 of FIG. 15A using a fourth-order scaling coefficient. The total data amount of this fourth order scaling coefficient is 21 bytes. FIG. 15D is a graph showing the transition of the speed with a 1/32 position resolution of FIG. 15A using a fifth-order scaling coefficient. The total data amount of the fifth order scaling coefficient is 10 bytes. As described above, the transition of the speed on the travel locus can be sufficiently expressed using the third-order, fourth-order, or fifth-order scaling factor.

Therefore, the probe car on-board device can greatly reduce the amount of transmission data by applying DWT to the measurement data and sending only the scaling coefficient of the order corresponding to the position resolution required by the receiving side. However, as the probe information between (1) and (2) in FIG. 10, the total data amount in the case of transmitting the variable-length-encoded traveling locus data and the fifth-order scaling coefficient of the speed data is 49.8 bytes. is there. Further, the total amount of probe information when transmitting a fourth-order scaling coefficient as speed data is 60.8 bytes, and the total amount of data when transmitting a third-order scaling coefficient as speed data is 82.8 bytes. . These data amounts are data amounts that can be transmitted from the probe car onboard device to the optical beacon using one or two frames. As described above, since four optical beacons are installed between (1) and (2) in FIG. 10, each time the probe car onboard device passes under the optical beacon, it accumulates until then. If the probe information is transmitted to the optical beacon, the amount of data transmitted once is further reduced.

  As described above, in this probe car system, the travel locus data is variable-length encoded and included in the probe information, and the measurement data is subjected to DWT, and the data sufficient to restore the scaling coefficient of the predetermined order is used as the probe information. Therefore, the total amount of data is extremely small, and it is possible to transmit probe information using a beacon.

(Third embodiment)
In the probe car system according to the third embodiment of the present invention, option information is included in the information sent from the in-vehicle device to the beacon. This optional information is transmitted whenever necessary. The option information can be transmitted when there is a margin in the data area of the data area due to the encoding of the probe information.

  FIG. 16 schematically shows this system. In addition to the probe information, the probe car on-board device 70 uploads, through the beacon 10, diagnostic information of the device indicating the travel distance and the failure status of the lamps as vehicle maintenance information. The vehicle maintenance information is transferred from the uplink collection / distribution center 301 to the car dealer or the car maintenance company 43. The car dealer or the car maintenance company 43 uses the vehicle maintenance information based on the vehicle maintenance information. For 50, it is recommended to replace the oil and parts by direct mail or to maintain the vehicle.

  As shown in FIG. 17, the probe car on-vehicle device 70 includes a lamp sensor (sensor α) 89 that detects a failure of lamps, a travel distance sensor (sensor β) 90 that detects a travel distance, and a malfunction of the device. Various vehicle sensor information management units 78 for managing detection information such as device failure sensors (sensor γ) 91 for detecting the sensor, and information managed by the various vehicle sensor information management units 78 is added to the probe information. And transmitted to the beacon 10. Other configurations are the same as those of the second embodiment (FIG. 6).

  FIG. 18 shows the data structure of information transmitted from the probe car onboard device 70 to the beacon 10. This frame includes a header 621, common measurement information 622, transmission destination code 623, travel locus data, and measurement data. In addition to the probe measurement information 625, vehicle maintenance information 626 indicating the failure status of the lamps, the travel distance, the status of various vehicle control device monitoring sensors, failure sensors, etc. (self-diagnosis information) is included. Yes.

  As described above, in this probe car system, the amount of data is reduced by encoding the probe information. Therefore, it is possible to include the vehicle maintenance information in the frame of the signal uploaded from the probe car onboard device to the beacon. Therefore, car dealers and car maintenance companies entering this system can collect maintenance information for each vehicle through beacons, and can provide timely services to users based on this information. . Further, when a failure with a high degree of urgency occurs in the vehicle, the maintenance information is transmitted prior to the probe information (the probe information is strongly compressed to secure a data area).

The information uploaded from the in-vehicle device to the beacon may include other optional information desired by each business entity, instead of the vehicle maintenance information.
Moreover, the method of including option information in the information transferred from the vehicle-mounted device to the beacon can be applied to the probe car system of the first embodiment.

(Fourth embodiment)
In the fourth embodiment of the present invention, a system in which a probe car in-vehicle device uploads information using a wireless medium together with a beacon will be described.
If you use only beacons to upload information,
(1) Since information cannot be sent unless the vehicle travels in the beacon communication area, the real-time property of information cannot be guaranteed. For this reason, the freshness of traffic information cannot be guaranteed (for example, the provision of information within 15 minutes is not guaranteed), and it is not possible to cope with an emergency such as the occurrence of an accident.
(2) Information cannot be collected where there is no beacon.
There is a problem. For this reason, in this system, information is uploaded using a wireless medium such as a mobile phone together with a beacon.

  FIG. 19 schematically shows this system. The information on the probe car onboard device 70 is uploaded to the beacon 10 and sent to the private information collection provider 42 through the uplink collection / distribution center 30, or the private information collection provider 42 on the mobile phone 92 from the probe car onboard device 70. Sent to. The probe car on-board device 70 uses the beacon 10 as much as possible, but transmits information using a mobile phone (wireless media) when there is no beacon even though information needs to be transmitted.

As shown in FIG. 20, the probe car on-vehicle device 70 includes a probe information transmission unit 94 that transmits information using wireless media, and a transmission media determination unit that determines whether information is transmitted using beacon or wireless media. 93. Other configurations are the same as those of the third embodiment (FIG. 17).
As the wireless media, communication media such as MCA wireless, digital MCA wireless, and wireless LAN can be used in addition to the mobile phone.

  In this probe car in-vehicle device 70, conditions (wireless media usage conditions) for transmitting information using wireless media are determined in advance, and the transmission media determining unit 93 is in a situation that matches the wireless media usage conditions. If there is, the probe information transmission unit 94 is selected as the information transmission unit, and in other situations, the probe information transmission unit 71 using the beacon is selected as the transmission unit.

The wireless media usage conditions include the following.
(1) Conditions for guaranteeing real-time traffic information Judgment condition example: Wireless media is used on the condition that, for example, 15 minutes have passed since the measurement time of the oldest measurement information.
(2) Conditions for guaranteeing real-time performance when sending emergency information Judgment conditions: Use wireless media on the condition that the emergency call button is pressed.
Judgment condition example: Wireless media is used on condition that the collision sensor has reacted.
(3) Conditions for ensuring the storage capacity of a buffer for storing data Example of determination conditions: Wireless media is used on the condition that the data size after compression has reached 80% of the buffer size.
(4) Conditions focusing on the travel distance of the probe car Judgment condition example: The wireless media is used on the condition that the vehicle has traveled a certain distance since the previous information was transmitted.
(5) Conditions for dealing with a situation in which the probe car stops and the passage under the beacon cannot be expected Example of determination conditions: Wireless media is used on condition that the ignition key is turned off and the engine is stopped.
Judgment condition example: Wireless media is used on condition that a sensor event for predicting a stop has occurred, such as a hazard being ON and a state where the speed is not more than a constant value for more than N seconds.
(6) Conditions for dealing with the occurrence of an event indicating a situation where passage under a beacon cannot be expected Example of determination conditions: The probe car navigation device has entered the parking lot (the distance from the parking lot POI is below a certain value, and Use the wireless media on the condition that it is determined that the vehicle has deviated from the road.
Judgment condition example: Radio media is used on the condition that the probe car navigation device has entered the expressway (the vehicle position is on the expressway) (the radio wave currently installed on the expressway) (Beacons only have a one-way communication function to send information to the in-vehicle device).
Determination condition example: Wireless media is used on condition that the navigation device of the probe car has determined that the vehicle has gone out of the road network (the vehicle position has deviated from the road network).
Judgment condition example: Wireless media is used on condition that the speed of the probe car has dropped suddenly (the difference in the average speed for the past N minutes is large.

  The flowchart of FIG. 21 shows the processing procedure of the probe car onboard device 70. The in-vehicle device 70 accumulates probe information (step 11). The transmission media determination unit 93 determines the wireless media usage conditions (step 12), and identifies whether or not the probe information needs to be transmitted by wireless media (step 13). If the wireless media usage conditions are met (Yes in step 13), the transmission media determination unit 93 selects the probe information transmission unit 94 as the transmission means, and the probe information transmission unit 94 uses the wireless media to probe information. Is transmitted (step 15). If the wireless media usage conditions are not met (No in step 13), the transmission media determination unit 93 selects the probe information transmission unit 71 as a transmission unit. When the probe car passes under the beacon (in the case of Yes in step 14), the probe information transmission unit 71 transmits the probe information through the beacon (step 16). If the probe car does not pass under the beacon (No in step 14), the accumulation of probe information (step 11) is continued. After transmitting the probe information through the wireless medium or the beacon, the probe information storage buffer of the travel locus measurement information storage unit 75 is cleared (step 17), and the procedure from step 11 is repeated.

  In this way, in the method of switching between transmission of information using a beacon and transmission of information using a wireless medium, the use of a beacon can reduce the communication fee and the load on the communication network. It is possible to supplement the weak point of the case where the real-time nature of information provision cannot be guaranteed and the point where information cannot be transmitted in an area without a beacon with wireless media.

  The probe car system of the present invention is a business that generates high value-added traffic information from probe information and provides information, a service business to users in cooperation with car dealers and car maintenance companies, customer support systems by group companies, etc. It can be applied to a wide range of business fields.

The schematic diagram which shows the probe car system in the 1st Embodiment of this invention The figure which shows the frame structure in the 1st Embodiment of this invention The figure which shows the data structure in the 1st Embodiment of this invention. The schematic diagram which shows the probe car system in the 2nd Embodiment of this invention. The figure which shows the data structure in the 2nd Embodiment of this invention. The block diagram which shows the structure of the probe car system in the 2nd Embodiment of this invention. The flowchart which shows operation | movement of the uplink collection and delivery center in the 2nd Embodiment of this invention. The figure explaining the encoding method of the driving | running | working locus data in the 2nd Embodiment of this invention. The figure which shows the code | cord | chord table used for encoding of driving locus data Map showing the area where the travel locus data and measurement data were measured The figure explaining DWT and IDWT used by encoding of the measurement data in the 2nd Embodiment of this invention The figure explaining the filter circuit of DWT and IDWT The figure explaining the division | segmentation and reconstruction of the signal in DWT and IDWT The figure explaining the specific example of DWT (A) Transition of speed represented by original data (b) Transition of speed represented by third-order scaling coefficient (c) Transition of speed represented by fourth-order scaling coefficient (d) Transition of speed represented by fifth-order scaling coefficient The schematic diagram which shows the probe car system in the 3rd Embodiment of this invention. The block diagram which shows the structure of the probe car system in the 3rd Embodiment of this invention. The figure which shows the data structure in the 3rd Embodiment of this invention. The schematic diagram which shows the probe car system in the 4th Embodiment of this invention. The block diagram which shows the structure of the probe car system in the 4th Embodiment of this invention. The flowchart which shows operation | movement of the probe car system in the 4th Embodiment of this invention. Diagram explaining uploading using conventional optical beacons

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Beacon 11 Each administrator system 20 Probe car 30 Uplink collection and distribution center 40 Network 41 Private information collection provider 42 Private information collection provider 43 Car dealer and car maintenance company 50 User 60 Frame 61 Regulation | regulation part 62 Private open part 70 Probe car In-vehicle device 71 Probe information transmission unit 72 Probe information encoding processing unit 73 Own vehicle position determination unit 74 Information transmission destination management unit 75 Traveling track measurement information storage unit 76 Measurement information valid / invalid determination unit 77 Sensor information collection unit 81 GPS antenna 82 Gyro 83 Door open / close signal detection sensor X
84 Hazard signal detection sensor Y
85 Seat belt signal detection sensor Z
86 Speed detection sensor A
87 Power output detection sensor B
88 Fuel consumption detection sensor C
89 Light sensor (Sensor α)
90 Travel distance sensor (Sensor β)
91 Equipment failure sensor (Sensor γ)
92 Cellular phone 93 Transmission media determining unit 94 Probe information transmitting unit 101 Center device communication unit 102 Probe information receiving unit 181 Low-pass filter 182 High-pass filter 183 Decimation circuit 184 Low-pass filter 185 High-pass filter 186 Decimation circuit 187 Adder circuit 191 Filter circuit 192 Filter circuit 193 Filter circuit 301 Uplink collection / distribution center 302 Beacon communication unit 303 Business operator code extraction unit 304 Transmission destination identification unit 305 Communication charge billing unit 306 Communication control unit 411 Business operator A communication device 421 Business Person B communication device 431 Operator X communication device 611 Header portion 612 Travel time measurement information between beacons 621 Header portion 622 Common measurement information 623 Transmission destination code 624 Probe information 625 Probe measurement information 626 Information for vehicle maintenance

Claims (15)

Encoded traveling locus data having an information transmission function to a beacon and encoded traveling locus data of an installed vehicle, encoded measurement data obtained by encoding measurement data measured while the vehicle is traveling, and a destination A transmission device that generates transmission information including a code indicating and transmits to a beacon;
A beacon that has a function of receiving information from the transmission device and transfers the transmission information received from the transmission device;
A distribution center that distributes the encoded travel locus data and the encoded measurement data sent through the beacon to their destinations;
A probe car system comprising: an information user that decodes the encoded travel locus data and encoded measurement data distributed from the distribution center to generate information for an information providing service.   The probe car system according to claim 1, wherein the transmission device includes identification information that contributes to measurement of travel time between beacons of the vehicle in the transmission information.   The information user provides at least a part of information for the information providing service to a system for measuring a travel time between beacons of the vehicle based on the identification information. The described probe car system.   The transmission device, after converting the travel locus data into statistically biased data, the data obtained by variable length encoding is the encoded travel locus data, and the measurement data is subjected to discrete wavelet transform, 2. The probe car system according to claim 1, wherein only the data that can reproduce the scaling coefficient of a predetermined order is selected as the encoded measurement data.   The probe car system according to claim 1, wherein the transmission device includes optional information used by a destination information user in the transmission information.   6. The probe car system according to claim 5, wherein the option information includes information related to maintenance of a vehicle on which the transmission device is mounted.   The transmission device includes a communication unit for the beacon and a wireless communication unit for the information user, and switches the communication unit for transmitting the transmission information according to a situation. Probe car system as described in.   The transmission device transmits the transmission information using the wireless communication means when the transmission information cannot be transmitted even if a predetermined time has elapsed from the measurement time point of the measurement data. 8. The probe car system according to 7.   The probe car system according to claim 7, wherein the transmission device transmits the transmission information using the wireless communication unit when the occurrence of an emergency situation is detected.   The transmission device transmits the transmission information using the wireless communication means when an accumulation capacity of a buffer for accumulating the encoded traveling locus data and encoded measurement data decreases to a predetermined amount or less. The probe car system according to claim 7.   The probe according to claim 7, wherein the transmission device transmits the next transmission information using the wireless communication unit when a travel distance from a point where the transmission information is transmitted reaches a certain distance. Car system.   8. The probe car system according to claim 7, wherein the transmission device transmits the transmission information using the wireless communication unit when detecting a stoppage of the vehicle or a transition operation to the stoppage. 9.   8. The probe car system according to claim 7, wherein the transmission device transmits the transmission information using the wireless communication means when the vehicle enters an area where the beacon is not installed.   8. The probe car system according to claim 7, wherein the wireless communication means performs communication using a mobile phone, MCA wireless, or wireless LAN. Self-vehicle position measuring means for measuring a traveling locus of the traveling vehicle, measuring means for measuring the traveling state of the traveling vehicle, encoding processing means for encoding the traveling locus data and the measurement data, and the encoding processing means A vehicle-mounted apparatus comprising: a communication unit that transmits transmission information including encoded data encoded by and a code indicating a destination to a beacon, and is used as a transmission apparatus of the probe car system according to claim 1.

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