Onboard equipment and probe information generation program

Abstract

To generate probe information in which the absolute time of day when power is turned on is recorded, while suppressing increases in cost and power consumption.SOLUTION: Onboard equipment 1 comprises: a satellite signal reception unit 4 for receiving a satellite signal from a satellite; a probe information generation unit 2a for generating probe information in which the absolute time of day calculated on the basis of the satellite signal is recorded; a power-on identification unit 2b for identifying power-on; a positioning success determination unit 2d for determining positioning success in the satellite signal reception unit; and an absolute time calculation unit 2e for measuring a positioning wait time from a first time of day when power-on is identified by the power-on identification unit till a second time of day when positioning success is determined by the positioning success determination unit, and subtracting the positioning wait time from the second time of day to calculate the absolute time of day when power is turned on. The probe information generation unit generates probe information in which the absolute time of day when power is turned on as calculated by the absolute time calculation unit is recorded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an in-vehicle device and a probe information generating program. [Background technology]

[0002] Electronic toll collection systems (hereafter referred to as ETC, ETC is a registered trademark) have been widely used for some time. ETC2.0 onboard units with built-in GPS (Global Positioning System) receivers are designed to use probe information that records absolute time calculated based on satellite signals from GPS satellites.

[0003] On the other hand, when the power is turned on, for example, by turning on an accessory (hereinafter referred to as ACC) switch, it takes some time for the almanac data, ephemeris data, etc. necessary for calculating absolute time and position to become valid, so absolute time cannot be calculated immediately. Therefore, it is not possible to generate probe information that records the absolute time at the time of power on. Regarding this point, for example, Patent Document 1 discloses a configuration that complements the time during the period when absolute time cannot be calculated by constantly operating the clock using a backup power source. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 074244 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the configuration disclosed in Patent Document 1 requires a backup power supply, which poses problems of high costs and increased power consumption.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide an on-board device and a probe information generation program that can appropriately generate probe information that records the absolute time when the power is turned on while suppressing increases in cost and power consumption. [Means for solving the problem]

[0007] According to the ETC on-board device of claim 1, the satellite signal receiving unit (4) receives satellite signals from satellites. The probe information generating unit (2a) generates probe information in which absolute time calculated based on the satellite signals is recorded. The power-on identifying unit (2b) identifies power-on. The positioning success determining unit (2d) determines whether positioning was successful in the satellite signal receiving unit. The absolute time calculating unit (2e) measures a positioning wait time from a first time when power-on is identified by the power-on identifying unit to a second time when positioning success is determined by the positioning success determining unit, and calculates the absolute time at power-on by subtracting the positioning wait time from the second time. The probe information generating unit generates probe information in which the absolute time at power-on calculated by the absolute time calculating unit is recorded.

[0008] The system measures the positioning wait time from the first time when power-on is identified to the second time when positioning success is determined, subtracts the positioning wait time from the second time to calculate the absolute time when power was turned on, and generates probe information in which the absolute time when power was turned on is recorded.This does not require a conventional backup power supply, and can appropriately generate probe information in which the absolute time when power was turned on is recorded while suppressing increases in cost and power consumption. [Brief explanation of the drawings]

[0009] [Figure 1] Functional block diagram showing the overall configuration of the first embodiment [Figure 2] flowchart [Figure 3] flowchart [Figure 4] Timing Chart [Figure 5] Timing Chart [Figure 6] Flowchart showing the second embodiment [Figure 7] flowchart [Figure 8] Timing Chart [Figure 9] Timing Chart DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments will be described with reference to the drawings. In subsequent embodiments, the description of the same parts as in the preceding embodiment may be omitted.

[0011] (First embodiment) A first embodiment will be described with reference to Figures 1 to 5. The ETC on-board unit is a device that performs wireless communication with an ETC roadside unit installed at a toll booth on a highway or the like, and is placed, for example, on the dashboard of a vehicle or near the driver's seat, into which an ETC card is inserted and removed. As shown in Figure 1, the ETC on-board unit 1 includes a control unit 2, a wireless communication unit 3, a GPS receiving unit 4 (corresponding to a satellite signal receiving unit), a memory unit 5, an input operation unit 6, a display unit 7, an audio output unit 8, a card control unit 9, a probe information recording unit 10, a vehicle speed sensor 11, and a power supply unit 12.

[0012] The control unit 2 is mainly configured with a microcomputer having a CPU, ROM, RAM, I / O, etc., and performs software processing by having the CPU execute a computer program stored in a non-transient physical storage medium, and hardware processing control by a dedicated electronic circuit, thereby controlling the operation of the ETC in-vehicle unit 1. The control unit 2 is also connected to the ACC switch of the key switch, and inputs an ACC ON signal indicating that the ACC switch is ON when the driver operates the ACC ON switch, and an ACC OFF signal indicating that the ACC switch is OFF when the driver operates the ACC OFF switch.

[0013] The wireless communication unit 3 performs short-range wireless communication employing the DSRC (Dedicated Short Range Communication) method with the ETC roadside unit 13. The GPS receiving unit 4 receives satellite signals transmitted from GPS satellites orbiting the sky. The GPS receiving unit 4 calculates the time, position (latitude and longitude), and speed based on the satellite signals received from four or more satellites, and outputs the calculated time information indicating the time, position information indicating the position, and speed information indicating the speed to the control unit 2.

[0014] The storage unit 5 is a non-volatile memory such as a flash memory, and stores various data such as pre-registered vehicle information as well as various data necessary for billing processing. The input operation unit 6 accepts operation inputs for various settings and information display using operation buttons, and outputs an operation input signal indicating the accepted operation input to the control unit 2.

[0015] The display unit 7 is, for example, a green LED that lights up while a billing process is being performed, and a red LED that lights up when a warning is issued. The control unit 2 outputs a first lighting instruction signal to the display unit 7 while a billing process is being performed, thereby lighting up the green LED. The control unit 2 outputs a second lighting instruction signal to the display unit 7 when a warning is issued, thereby lighting up the red LED.

[0016] The audio output unit 8 is, for example, a speaker. The control unit 2 outputs an audio output instruction signal to the audio output unit 8, thereby causing the audio output unit 8 to output a predetermined audio. When the ETC card 14 is inserted into a card slot (not shown) and installed, the card control unit 9 recognizes the installed ETC card 14, reads out card information recorded on the ETC card 14, and outputs the read card information to the control unit 2. The probe information recording unit 10 records, as probe information, traveling information including time information, position information, and speed information output from the GPS receiving unit 4 to the control unit 2, and behavior information including sudden deceleration information calculated from the position information and speed information. The vehicle speed sensor 11 detects the vehicle speed.

[0017] The power supply unit 12 is configured, for example, by a secondary battery and is connected to the vehicle battery via the ACC switch of the key switch. When the ACC switch is turned on, the power supply unit 12 generates a predetermined DC voltage and supplies the generated DC voltage to each part of the ETC vehicle-mounted device 1 to supply power.

[0018] The control unit 2 includes a probe information generating unit 2a, a power-on specifying unit 2b, a power-off specifying unit 2c, a positioning success determining unit 2d, and an absolute time calculating unit 2e. Each of these units 2a to 2e executes a probe information generating program.

[0019] When time information, position information, and speed information are input from the GPS receiving unit 4, the probe information generating unit 2a generates, as probe information, traveling information including the input time information, position information, and speed information, and behavior information including sudden deceleration information calculated from the position information and speed information. The power on identifying unit 2b identifies power on when an ACC on signal is input. The power off identifying unit 2b identifies power off when an ACC off signal is input.

[0020] The positioning success determination unit 2d determines whether or not positioning has been successful in the GPS receiving unit 4. When the positioning success determination unit 2d determines that the almanac data, ephemeris data, etc. have become valid and that the time information, position information, and velocity information input from the GPS receiving unit 4 are valid, it determines that positioning has been successful.

[0021] The absolute time calculation unit 2e measures the positioning wait time from the first time when the power-on determination unit 2b identifies that the power was on to the second time when the positioning success determination unit 2d determines that the positioning was successful, and calculates the absolute time at the time of power-on by subtracting the positioning wait time from the second time. In this case, the absolute time calculation unit 2e may measure the positioning wait time using either the measurement function of the GPS receiver 4 or the measurement function of the control unit 2. Since the measurement function of the GPS receiver 4 is generally more accurate than the measurement function of the control unit 2, using the measurement function of the GPS receiver 4 makes it possible to measure the positioning wait time with high accuracy. When the absolute time at the time of power-on is calculated by the absolute time calculation unit 2e, the probe information generation unit 2a generates probe information in which the calculated absolute time at the time of power-on is recorded.

[0022] Next, the operation of the above-described configuration will be described with reference to Fig. 2 to Fig. 5. The control unit 2 monitors the input of an ACC-ON signal while the power is off, and starts the power-on process when it detects the input of the ACC-ON signal. When the control unit 2 starts the power-on process, it identifies the time when the power was turned on as the first time (S1, corresponding to the power-on identification procedure), and starts timing the positioning wait time (S2). When the control unit 2 starts timing the positioning wait time, it determines whether the power has been turned off (S3) and whether positioning has been successful in the GPS receiver 4 (S4).

[0023] If the control unit 2 determines that the power was turned off by detecting the input of an ACC-off signal before the GPS receiver 4 successfully performed positioning (S3: YES), it records a power-on event (S5) and ends the power-on process. In this case, the control unit 2 records the power-on event as "without absolute time" because the GPS receiver 4 previously performed positioning successfully, the almanac data, ephemeris data, etc., have not yet become valid, and the absolute time at the time of power-on has not yet been calculated.

[0024] If the control unit 2 determines that positioning was successful in the GPS receiver 4 before powering off (S4: YES, corresponding to the positioning success determination step), it ends timing of the positioning wait time (S6) and identifies the time at which positioning was successful as the second time (S7). The control unit 2 calculates the time from the first time to the second time as the positioning wait time (S8), subtracts the positioning wait time from the second time to calculate the absolute time at which the power was turned on, and records the power-on event (S9, corresponding to the absolute time calculation step). In this case, the control unit 2 records the power-on event as "with absolute time" because the almanac data, ephemeris data, etc. have become valid and the absolute time at which the power was turned on has been calculated.

[0025] The control unit 2 determines whether the calculated positioning wait time is 255 seconds or more (S10). If the control unit 2 determines that the calculated positioning wait time is 255 seconds or more, that is, that positioning was successful after 255 seconds had elapsed since the power was turned on (S10: YES), the control unit 2 records a 255-second elapsed event (S11) and records a GPS positioning start event (S12). On the other hand, if the control unit 2 determines that the calculated positioning wait time is less than 255 seconds, that is, that positioning was successful before 255 seconds had elapsed since the power was turned on (S10: NO), the control unit 2 does not record a 255-second elapsed event, but records a GPS positioning start event (S12).

[0026] The control unit 2 calculates the time, position, and speed, generates driving information and behavior information based on these calculated values ​​as probe information (S13, corresponding to the probe information generation step), and records the generated probe information (S14). The control unit 2 determines whether the power has been turned off (S15). If it determines that the power has not been turned off (S15: NO), the control unit 2 returns to step S13 and repeats step S13 and subsequent steps. That is, the control unit 2 generates probe information every time time information, position information, and speed information are input from the GPS receiver 4, for example, every predetermined traveling distance, and records the generated probe information. If the control unit 2 determines that the power has been turned off by detecting the input of an ACC-off signal (S15: YES), it ends the power-on process.

[0027] As shown in FIG. 4, when 255 seconds have passed since the power was turned on (t1), if the control unit 2 determines that positioning has been successful (t2), it records the power-on event as "with absolute time," sets the time as a calculated value, and sets the position and speed as undetermined values, and generates and records probe information. The control unit 2 records a 255-second-elapsed event, sets the time as a calculated value, and sets the position and speed as undetermined values, and generates and records probe information. The control unit 2 records a GPS positioning start event, sets the time, position, and speed as calculated values, and generates and records driving information and behavior information based on these calculated values ​​as probe information.

[0028] 5, if the control unit 2 determines that positioning has been successful (t11) before 255 seconds have elapsed since the power was turned on (t12), it records the power-on event as "with absolute time," sets the time as a calculated value, and sets the position and speed as undetermined values, and generates and records probe information.The control unit 2 records a GPS positioning start event, sets the time, position, and speed as calculated values, and generates and records driving information and behavior information based on these calculated values ​​as probe information.

[0029] As described above, according to the first embodiment, the following advantageous effects can be obtained. In the ETC on-board unit 1, the positioning wait time from the first time when power-on is determined to the second time when positioning success is determined is measured, and the positioning wait time is subtracted from the second time to calculate the absolute time when power was turned on, and probe information in which the absolute time when power was turned on is recorded is generated. This does not require a conventional backup power supply, and can suppress increases in cost and power consumption while appropriately generating probe information in which the absolute time when power was turned on is recorded. In addition, the generated probe information can be appropriately recorded.

[0030] (Second embodiment) The second embodiment will be described with reference to Figures 6 to 9. The first embodiment is configured to record a power-on event and a 255-second elapsed event when the GPS receiver 4 determines that positioning has been successful, but the second embodiment is configured to record a power-on event and a 255-second elapsed event when power-on processing is started, and to rewrite the power-on event and the 255-second elapsed event when the GPS receiver 4 determines that positioning has been successful.

[0031] When the control unit 2 starts the power-on process, it records the power-on event as "without absolute time" (S21), records a 255-second lapse event (S22), and performs the above-described steps S1 and onward. If the control unit 2 determines that the power was turned off by detecting input of an ACC-off signal before positioning was successful in the GPS receiver 4 (S3: YES), it does not record the power-on event and ends the power-on process.

[0032] If the control unit 2 determines that positioning was successful in the GPS receiver 4 before powering off (S4: YES), it calculates the time from the first time to the second time as a positioning wait time (S8), subtracts the positioning wait time from the second time to calculate the absolute time at power-on, and rewrites the power-on event from "absolute time not included" to "absolute time included" (S23, corresponding to the absolute time calculation step). If the control unit 2 determines that the calculated positioning wait time is 255 seconds or more, that is, that positioning was successful after 255 seconds have elapsed since powering on (S10: YES), it rewrites the 255-second elapsed event (S24). Thereafter, the control unit 2 performs the above-described steps S12 and onward.

[0033] As shown in FIG. 8, when the control unit 2 determines that the power is on (t0), it records the power-on event as "without absolute time" and records a 255-second elapsed event. Then, after 255 seconds have elapsed since the power was turned on (t1), the control unit 2 determines that positioning has been successful (t2). Then, the control unit 2 rewrites the power-on event from "without absolute time" to "with absolute time," sets the time to a calculated value, and sets the position and speed to undetermined values, and generates and records probe information. The control unit 2 rewrites the 255-second elapsed event, sets the time to a calculated value, and sets the position and speed to undetermined values, and generates and records probe information. The control unit 2 records a GPS positioning start event, sets the time, position, and speed to calculated values, and generates and records driving information and behavior information based on these calculated values ​​as probe information.

[0034] As shown in Figure 9, when the control unit 2 determines that the power is on (t0), it records the power-on event as "without absolute time" and records a 255-second event. Then, before 255 seconds have elapsed since the power was turned on (t12), if the control unit 2 determines that positioning has been successful (t11), it rewrites the power-on event from "without absolute time" to "with absolute time," sets the time to a calculated value, and sets the position and speed to undetermined values, and generates and records probe information. The control unit 2 records a GPS positioning start event, sets the time, position, and speed to calculated values, and generates and records driving information and behavior information based on these calculated values ​​as probe information.

[0035] As described above, according to the second embodiment, it is possible to obtain the same effects as the first embodiment, and it is possible to appropriately generate probe information in which the absolute time when the power was turned on is recorded, while suppressing increases in cost and power consumption. In this case, even if there is an unexpected power loss, it is possible to record a power-on event before the power is turned off.

[0036] (Other embodiments) Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0037] Although GPS has been exemplified as one of the Global Navigation Satellite Systems (GNSS), the present invention can also be applied to other systems such as GLONASS, Galileo, and BeiDou.

[0038] The control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. [Explanation of symbols]

[0039] In the drawing, 1 is an ETC onboard unit (onboard unit), 2 is a control unit, 2a is a probe information generation unit, 2b is a power-on identification unit, 2d is a positioning success determination unit, 2e is an absolute time calculation unit, 4 is a GPS receiving unit (satellite signal receiving unit), and 10 is a probe information recording unit.

Claims

1. a satellite signal receiving unit (4) for receiving a satellite signal from a satellite; a probe information generating unit (2a) that generates probe information in which absolute time calculated based on the satellite signal is recorded; a power-on identification unit (2b) for identifying whether the power is on; a positioning success determination unit (2d) that determines whether positioning has been successful in the satellite signal receiving unit; an absolute time calculation unit (2e) that measures a positioning wait time from a first time when the power-on determination unit identifies that the power is on to a second time when the positioning success determination unit determines that the positioning is successful, and calculates an absolute time at the time of power-on by subtracting the positioning wait time from the second time, The probe information generating unit generates probe information in which the absolute time calculated by the absolute time calculating unit at the time of power-on is recorded.

2. 2. The vehicle-mounted device according to claim 1, further comprising a probe information recording unit (10) for recording the probe information generated by the probe information generating unit.

3. 3. The vehicle-mounted device according to claim 2, wherein the probe information recording unit records a power-on event immediately after the absolute time calculation unit calculates the absolute time when the power is turned on, thereby recording probe information in which the absolute time when the power is turned on is recorded.

4. 3. The vehicle-mounted device according to claim 2, wherein the probe information recording unit records a power-on event immediately after the power-on identification unit identifies the power-on, and rewrites the power-on event immediately after the absolute time calculation unit calculates the absolute time at which the power was turned on, thereby recording probe information in which the absolute time at which the power was turned on is recorded.

5. 2. The vehicle-mounted device according to claim 1, wherein the absolute time calculation unit measures the positioning wait time using a measurement function of the satellite signal receiving unit.

6. A control unit (2) of an in-vehicle device (1) having a satellite signal receiving unit (4) that receives satellite signals from a satellite, a power-on identification procedure for identifying power-on; a positioning success determination step for determining whether the positioning has been successful in the satellite signal receiving unit; an absolute time calculation step of measuring a positioning wait time from a first time when power-on is identified by the power-on identification step to a second time when positioning success is determined by the positioning success determination step, and calculating an absolute time at power-on by subtracting the positioning wait time from the second time; a probe information generating program for executing a probe information generating procedure for generating probe information in which the absolute time at power-on calculated by the absolute time calculating procedure is recorded.

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