JP2005107876A - Location information monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a location information monitoring system that, when acquiring location information about a moving body, determines whether the location information is correct or not and precludes a determination of a movement of the moving body if the location information is incorrect. <P>SOLUTION: The location information monitoring system, which monitors location information about a moving body to determine a movement of the moving body according to a change in the location information, compares the latest location information and past location information out of location information acquired by a location detection part, to determine whether the latest location information is correct or not according to the distance between points indicated by the location information. A movement of the moving body is determined in dependence on such location information as the determination finds correct. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a position information monitoring system that acquires position information of a moving body and monitors the position of the moving body, the presence / absence of movement, and the movement state.

Conventionally, a mobile terminal that acquires position information including position coordinates based on base station information or GPS signals of a mobile communication network is carried by the mobile body, and the moving status or current position of the mobile body is determined by the position information acquired by the mobile terminal. Monitoring systems are known.
In this conventional system, an error that is an amount representing the accuracy of the acquired position information is determined depending on the situation when the position information is obtained, that is, the arrangement situation of the GPS satellite, the arrangement situation of the mobile communication base station, the radio wave propagation situation, etc. The amount varies.

For this reason, for example, there is a moving body monitoring system disclosed in Patent Document 1 in which a predetermined error range is set according to the acquisition state of position information and the presence or absence of movement is appropriately determined in consideration of the error range. . In this moving body monitoring system, it is determined that the moving body is moving when there is no overlap between error ranges centered on a plurality of pieces of position information acquired at different times, instead of moving determination using only position information. doing.

International Publication No. 02/035492 Pamphlet

However, it is rare to acquire position information that is far from the current location of the moving object when the acquisition status of the position information is extremely poor, or when an unexpected situation such as garbled data occurs. It is in.
In the mobile body monitoring system described in Patent Document 1, such a large error with respect to position information that occurs infrequently is not assumed. In this case, there is a problem that the error range stays within the assumed range and the moving state of the moving body and the current position are erroneously determined.
In addition, in the moving object monitoring system described in Patent Document 1, assuming such a large error that may occur rarely, if a large error range is set in advance in the position information, even if the moving object moves, the error range overlaps. It takes a long time to disappear, and there is a possibility that the determination of the movement of the moving object is delayed. In particular, in the case of a system that acquires position information intermittently to detect theft of a mobile object, the response may be delayed, which may be a serious case.

Therefore, in order to solve the above-described problems, the present invention determines whether the position information is correct by acquiring the position information when the position information is acquired, and outputs whether the position information is incorrect. The object is to provide a position information monitoring system to prevent.

In order to achieve the above object, a position information monitoring system according to the present invention is a position information monitoring system that monitors position information of a moving body and determines the movement of the moving body based on a change in the position information. A position detection unit that acquires information, a position storage unit that stores position information acquired by the position detection unit, and a point-to-point indicated by each position information by comparing the latest position information and past position information A pass / fail determination unit that determines pass / fail of the latest position information based on the distance of the mobile station, and a movement determination unit that determines the movement of the moving body based on the position information determined to be good by the determination unit. It is said.

Preferably, the pass / fail determination unit compares the latest position information with the past position information, and if it is determined that the latest position information is not, the latest position information is the past position information. Compared with the position information acquired at a time different from that of the position information, the quality of the latest position information is determined again.

Preferably, the information processing apparatus further includes monitoring setting means for setting the monitoring operation of the position information to start and stop, and the movement determination unit obtains the position information when the monitoring operation is set to start by the monitoring setting means. After being stored in the position storage unit, the position information determined to be good by the good / bad determination unit is monitored, and the position information determined to be good is separated from the position information at the start of the monitoring operation by a predetermined distance or more. Then, the movement of the moving body is determined and an abnormal signal is output.

According to the position information monitoring system of the present invention, it is possible to determine whether the position information is good or bad by a simple comparison process, and it is possible to prevent movement due to incorrect position information.
Further, when determining whether the position information is good or bad, even if the past position information to be compared with the latest position information is position information indicating an incorrect position, the latest position information is compared with the past position information. When it is determined that the position information is not good, it is configured to determine whether the latest position information is good or not after comparing again with different comparison targets, so that the quality of the position information can be accurately determined.

Embodiments of a position information monitoring system according to the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a diagram showing the overall configuration of a position information monitoring system of the present invention. The position information monitoring system of the present invention transmits position information acquired by the mobile terminal 1 attached to the moving body 50 to the center device 3 and manages the position and moving state of the moving body 50 by the center device 3. . In the present invention, the term “moving body” is a concept that includes cars, motorcycles, bicycles, people, pets, bags, safes, works of art, precious metals, etc., except for things that do not move, such as real estate.

The mobile terminal 1 calculates and stores position information composed of latitude and longitude based on the GPS signal received from the GPS satellite 6 and the base station information received from the mobile phone base station 4. The position information stored in the portable terminal 1 is transmitted to the center device 3 at a predetermined timing. The mobile terminal 1 transmits position information to the center apparatus 3 in response to the position information request command received from the center apparatus 3.

The mobile terminal 1 includes a monitoring mode and a release mode as operation modes. The monitoring mode is a mode for monitoring the movement of the moving body 50 that carries the mobile terminal 1. The release mode is a state where the monitoring mode is released. When the operation mode is set to the monitoring mode, the mobile terminal 1 acquires position information at predetermined intervals (for example, 1 minute), and monitors the change in the position information to carry the mobile terminal 1 An abnormality such as 50 theft is detected and an abnormality signal is transmitted to the center device 3.

The center device 3 is a device that manages position information and abnormality signals received from the mobile terminal 1. The center device 3 is installed in the monitoring center 2 such as a security company, and is managed and operated by an organization that provides location confirmation services to a plurality of objects. In the monitoring center 2, when it is determined that the mobile body 50 that carries the mobile terminal 1 needs some kind of handling, the center device 3 instructs a predetermined coping person to appropriately deal with the target mobile body 50.
Further, when the center device 3 receives a request for confirming the position of the mobile terminal 1 from the user of the mobile terminal 1 via telephone, FAX, the Internet, or the like, the center device 3 transmits a position request command to the corresponding mobile terminal 1. When position information is received from the portable terminal 1 in response to the position request command, the current position of the portable terminal 1 or the movement history is output to the user based on the received position information.

Next, the configuration of the mobile terminal 1 will be described. FIG. 2 is a diagram illustrating functional blocks of the mobile terminal 1.
The mobile terminal 1 includes a wireless communication unit 10, an operation unit 14, a storage unit 15, and a control unit 16.
The wireless communication unit 10 includes a GPS receiving unit 13 that receives a GPS signal from the GPS satellite 6, a base station information receiving unit 12 that receives base station information from the mobile phone base station 4, and a mobile phone base station 4 and a communication The communication unit 11 is configured to communicate with the center apparatus 3 via the network 5.
The operation unit 14 is input means for the user to perform a setting operation for setting the mobile terminal 1 in the monitoring mode and a releasing operation for canceling the setting operation. The operation unit 14 may be configured separately from the mobile terminal 1 and connected to the mobile terminal 1 for use.
The storage unit 15 includes a ROM, a RAM, and the like, and records various information used for processing. Moreover, the memory | storage part 15 has memorize | stored the position table as shown in FIG. 4 as a table which records the positional information on the portable terminal 1. FIG.

The control unit 16 includes a microprocessor, a semiconductor memory, and the like, and controls the entire mobile terminal 1.
The control unit 16 includes a position detection unit 17 that acquires position information based on information received by the wireless communication unit 10, a pass / fail determination unit 18 that determines pass / fail of the position information, and presence / absence of movement based on a change in the position information. And a movement determination unit 19 for determination.
When receiving the position information request command from the center device 3 via the communication unit 11, the control unit 16 acquires the position information of the mobile terminal 1 and transmits it to the center device 3.
Further, the control unit 16 is set to the monitoring mode based on the set operation by the operation unit 14. When set to the monitoring mode, the control unit 16 monitors the position of the mobile terminal 1 by the operation of each unit described later and determines whether or not an abnormality such as theft has occurred in the mobile object 50 that carries the mobile terminal 1. To do.

The position detection unit 17 obtains information from the GPS satellite 6 or information from the communicable mobile phone base station 4 via the wireless communication unit 10, and position coordinates indicating the current position of the mobile terminal 1 from the acquired information To obtain position information.
The position detection unit 17 receives information from the GPS satellite 6 and information from the mobile phone base station 4 that can communicate with each other via the wireless communication unit 10 at a predetermined timing. The number of telephone base station information is grasped. At this time, even if the number of received GPS signals is not three or more, the position detection unit 17 uses the mobile phone base station information in a complementary manner with the GPS signals, so that the current state of the mobile terminal 1 is based on the principle of three-point surveying. Calculate the position. In addition, the position detection unit 17 sets an error range in the position information based on the number and arrangement of the GPS satellites 6 and the mobile phone base stations 4 used for calculating the position. A method of setting an error range in the position information is conventionally known, and various realization methods have been proposed. Therefore, detailed description here is omitted.
The position detection unit 17 outputs the calculated current position, positioning time, error range, and the like to the storage unit 15 as position information.
The storage unit 15 records the position information input from the position detection unit in the position table.

The current position may be calculated by an external positioning server (not shown). In this case, GPS information and base station information acquired by the position detection unit 17 are transmitted to an external positioning server (not shown) via the communication unit 11. The positioning server calculates the current position of the mobile terminal 1 based on the received information and transmits it to the mobile terminal 1. The position detector of the mobile terminal 1 obtains position information based on the position received from the positioning server.

The current position included in the position information, that is, the position calculated from the GPS information or the base station information, may be obtained when the number of GPS satellites 6 or mobile phone base stations 4 that can receive information by the wireless communication unit 10 is extremely small, When the GPS satellite 6 or the mobile phone base station 4 to be acquired is switched instantaneously or when signal corruption occurs, the position is rarely far from the actual location.
The pass / fail judgment unit 18 determines whether the current position included in the position information acquired by the position detection unit 17 based on the position table in the storage unit 15 is normally measured (OK) or is erroneously measured and is the actual existence position. It is determined whether or not it is far away (NG). The determination result is output to the storage unit 15 and stored in the position table as a pass / fail determination flag.

The movement determination unit 19 operates when the mobile terminal 1 is set to the monitoring mode by the setting operation of the operation unit 14. The movement determination unit 19 acquires the position information of the mobile terminal 1 from the position table of the position detection unit 17 or the storage unit 15. Then, the movement determination unit 19 has an abnormality such as theft in the mobile body 50 that carries the mobile terminal 1 based on the position information determined to be normal (OK) by the pass / fail determination unit 18 among the acquired position information. It is determined whether or not. When it is determined that an abnormality has occurred, the movement determination unit 18 transmits an abnormality signal to the center device 3 via the communication unit 13.

Next, the configuration of the center device 3 will be described. FIG. 3 is a diagram illustrating functional blocks of the center device 3.
The center device 3 is installed in the monitoring center 2 and includes a communication unit 31, a storage unit 32, an operation unit 33, an output unit 34, and a control unit 35.
The communication unit 31 communicates with the mobile terminal 1 via the communication network 5 and the mobile phone base station 4.
The storage unit 32 includes a ROM, a RAM, and the like, and records various information used for processing, the position information of the mobile terminal 1, and the like.
The operation unit 33 is a device that allows a center member of the monitoring center 2 to perform an input operation on the center device 3 and includes a keyboard, a mouse, and the like.
The output unit 34 is a means for outputting the current position, movement trajectory, presence / absence of abnormality of the mobile terminal 1 to a display (not shown), a WEB server, or the like. The output unit 34 refers to the pass / fail determination flag of the position information received from the mobile terminal 1 and outputs only “OK”, that is, the position information 34 that is normally measured.
The control unit 35 includes a microprocessor, a semiconductor memory, and the like, and controls the center device 3 as a whole.

When the center device 3 receives a position confirmation request for the mobile terminal 1 from the user via a telephone, a FAX, the Internet, or the like, the center device 3 transmits a position request command from the communication unit 31 to the corresponding mobile terminal 1.
And if the positional information is received from the corresponding portable terminal 1, the positional information normally positioned by the output unit 34 is output. The monitoring center 2 outputs the current position, movement history, and the like of the corresponding mobile terminal 1 to the user based on the output position information.

Further, when the center device 3 receives an abnormal signal from the mobile terminal 1, the center device 3 outputs position information and abnormal content included in the abnormal signal. The center member of the monitoring center 2 refers to the output information and instructs the coordinator to search for the mobile object 50 that carries the mobile terminal 1.

The position information monitoring system of the present invention is roughly configured by the mobile terminal 1 and the center device 3 as described above.
The operation of the position information monitoring system of the present invention will be described below based on the above configuration.

First, the quality information judgment operation of the location information monitoring system of the present invention will be described.
FIG. 5 is a flowchart showing the pass / fail judgment operation of the position information by the pass / fail judgment unit 18.
FIG. 6 is a schematic diagram showing the interrelationship of the position information A to D in the position table shown in FIG. In FIG. 6, point positions A to D indicated by crosses indicate position coordinates included in the respective position information.

When the position detection unit 17 acquires new position information (step S100—Yes), the pass / fail determination unit 18 refers to the position table in the storage unit 15, and the position information acquired immediately before is the past predetermined time (for example, 12 hours). It is determined whether or not the information is within (step S101). If the position information acquired immediately before is within the past predetermined time (step S101-Yes), the latest position information is compared with the position information of the immediately previous time, and the position between both positions is determined from each position and time. The moving speed of the portable terminal 1 is calculated. If the calculated moving speed is lower than the threshold value (step S102—Yes), it is determined that the latest position information is normally positioned information (OK) (step S103), and the determination result is stored. It outputs to the part 15 (step S104). The storage unit 15 stores the input determination result in the position table.

In step S102, when the calculated moving speed is higher than the threshold value (step S102-No), the process proceeds to step S105.
If position information within the past predetermined time is not recorded in the position table (step S101-No), there is no position information to be compared, and the latest position information is information that has been normally measured (OK). (Step S103).

The pass / fail determination unit 18 determines whether or not the moving speed per unit time is a realistic speed by the process of step 102. Therefore, the threshold value used for the above determination is set to an appropriate value that is considered as the upper limit of the moving speed of the moving object. For example, 150 km / h that can be considered as the speed of the vehicle, or 500 km / h that can be considered as the speed of the Shinkansen. In this example, an example in which the threshold value of the moving speed is set to 500 km / h will be described.

In FIG. 6, for example, it is assumed that the latest position information is the point position C. The pass / fail judgment unit 18 compares the point position C with the point position B, which is position information immediately before the point position C, to calculate the moving speed of the mobile terminal 1. Since the distance between C and B is 20000 m and the positioning time interval is 1 minute, the moving speed is obtained as 1200 km / h. The quality determination unit determines that the moving speed between C and B exceeds a threshold value (500 km / h).

Returning again to FIG. When comparing the latest position information and the previous position information, if the previous position information includes an incorrect position, even if the latest position information includes an accurate position, There is a possibility that the moving speed (distance / time) between the latest position information and the previous position information becomes an abnormal value, and it is erroneously determined that the latest position information is incorrect. Therefore, as a result of comparing the latest position information with the previous position information, if the moving speed between the two positions is higher than the threshold value, the pass / fail judgment unit 18 further determines that the latest position information is the previous position information. Process to compare with information.

Therefore, as a result of comparing the latest position information with the previous position information, if the moving speed between the two positions is higher than the threshold (No in step S102), first, the position table of the storage unit 15 is referred to. Then, it is determined whether or not the position information acquired two times before in the past predetermined time (for example, 12 hours) exists (step S105). If the position information acquired two times before is information within the past predetermined time (step S105-Yes), the latest position information is compared with the position information of the previous time, and the mobile phone between the two positions from each position and time is compared. The moving speed of the terminal 1 is calculated.
If the calculated moving speed is lower than the threshold value (step S106—Yes), it is determined that the latest position information is information (OK) that has been normally measured (step S103), and the determination result is stored. It outputs to the part 15 (step S104). The storage unit 15 stores the input determination result in the position table.

In step S106, when the calculated moving speed is higher than the threshold value (step S106-No), it is determined that the latest position information is incorrect (NG) (step S107), and the determination result is stored. It outputs to the part 15 (step S104). The storage unit 15 stores the input determination result in the position table.
If the previous position information has not been acquired in the past predetermined time (step S105-No), there is no position information to be compared, so the latest position information is incorrect based on the determination result of step 102 ( NG) (step S107).

Therefore, in the case of the point position C in FIG. 6, the moving speed with respect to the point position B, which is the previous position information, is equal to or higher than the threshold value. A point position A that is position information of the last time is compared with the point position C. Since the distance between C and A is 20050 m and the positioning time interval is 2 minutes, the moving speed is obtained as 601.5 Km / h. The quality determination unit 18 determines that the moving speed between C and A exceeds the threshold value (500 km / h).
Then, the pass / fail determination unit 18 determines that the position information C is the wrong position information (NG) that is in an abnormal positional relationship as a result of comparing the point position C, which is the latest position information, with the previous position information and the previous position information. The determination result is output to the storage unit 15. The storage unit 15 stores the input determination result in the position table.

Next, a case where the position detection unit 17 acquires new position information and the latest position information is obtained as the point position D in FIG. 6 will be described.
First, the pass / fail judgment unit 18 compares the point position D with the point position C that is the previous position information. Since the distance between D and C is 20010 m and the positioning time interval is 1 minute, the moving speed is obtained as 1200.6 Km / h. The quality determination unit 18 determines that the moving speed between D and C exceeds a threshold value (500 km / h).
The pass / fail judgment unit 18 then compares the point position D with the point position B, which is the previous position information. Since the distance between D and B is 10 m and the positioning time interval is 2 minutes, the moving speed is obtained as 0.3 km / h. The quality determination unit 18 determines that the moving speed between D and B is equal to or less than a threshold value (500 km / h).
Since the point position D, which is the latest position information, is in a normal positional relationship with the previous position information, the pass / fail determination unit 18 determines that the latest position information is normal (OK) and stores the determination result. To the unit 15. The storage unit 15 stores the input determination result in the position table.

Next, the movement determination operation of the mobile terminal 1 in the position information monitoring system of the present invention will be described.
FIG. 7 is a flowchart showing the movement determination operation of the mobile terminal 1.
FIG. 8 is a schematic diagram showing the correlation between error ranges.

When the portable terminal 1 is set to the monitoring mode by the setting operation of the operation unit (step S200—Yes), the position detection unit 17 acquires position information (step S201). If the pass / fail judgment flag of the position information is “OK” (step S202—Yes), the position information is recorded in the position table as monitoring start position information (step S203), and monitoring of the position information is started. On the other hand, if the pass / fail determination flag is “NG”, the position information is acquired again (step S202—No). When the release operation of the operation unit 14 is detected (step S204—Yes), the monitoring is terminated and the flow is exited.
When the monitoring is started, it is confirmed whether or not a predetermined time (for example, 1 minute) has elapsed since the previous position information was acquired by a time measuring unit (not shown) (step S205). When the predetermined time has elapsed (step S205—Yes), the latest position information is acquired by the position detector 17 (step S206). If the pass / fail judgment flag of the latest position information is “NG” (step S207—No), the process returns to step S204.
On the other hand, if the pass / fail judgment flag of the latest position information is “OK” (S207—Yes), the latest position information is compared with the monitoring start position information (step S208). Here, it is determined whether the position error range included in the position information at the start of monitoring and the position error range included in the latest position information overlap each other or are separated from each other.

In FIG. 8, for example, it is assumed that the point position A is calculated as the position of the mobile terminal 1 at the start of monitoring, and the point position B is calculated as the latest position of the mobile terminal 1. If the error range of the point position A is 30 m (circle 500) and the error range of the point position B is 30 m (circle 510), there is a region (region 520) that overlaps these error ranges (step S208—Yes). . At this time, it is determined that the mobile terminal 1 is not moving, and the process returns to step S204. That is, when the actual location of the mobile terminal 1 is on an area where the error range overlaps (area 520), the position of the mobile terminal 1 is determined to be either the point position A or the point position B depending on the position information acquisition status. There is a possibility that. For this reason, if the error regions overlap, the mobile terminal 1 may not be moving, so that the movement determination is not performed.

On the other hand, if the error range of the point position A is 30 m (circle 500) and the error range of the point position B is 5 m (circle 511), the error range does not overlap (No in step S208), and the mobile terminal 1 moves. It determines with having carried out and it progresses to step S209. In step S209, the fact that the mobile terminal 1 being monitored has moved indicates that the mobile object 50 carrying the mobile terminal 1 has been stolen. 3 to send. The abnormal signal includes position information recorded in the position table. In the monitoring center 2, it is possible to take appropriate measures such as expediting a counselor to the site based on the abnormality signal received by the center device 3 or contacting the user of the mobile terminal 1.

Therefore, according to the position information monitoring system configured and operated in this manner, it is possible to determine whether the position information is good or bad by simply comparing the latest position information with the previous position information or the previous position information. Whether or not the position information is present can be determined simply and at high speed.

In addition, if the quality of the position information is determined only by comparing the latest position information with the previous position information, even if the latest position information is normally measured, the information obtained by the previous incorrect position information is obtained. Depending on the position information monitoring system, the latest position information may be compared with the previous position information and determined to be in an abnormal positional relationship. In addition, since it is configured to be compared with the previous position information, it can be prevented that the position information that has been normally positioned after that is erroneously determined by one position information that has been erroneously positioned is erroneously determined. The quality of information can be determined with high accuracy.
In addition, as a result of this, when detecting theft of the moving object 50 or the like from the position information that is intermittently measured as in the present position information monitoring system, a false alarm caused by erroneous determination of the quality of the position information. And false alarms can be reduced.

Note that it is very rare that a position that is far away from the actual position is erroneously measured. For this reason, in the present embodiment, it is assumed that the wrong positioning is not performed twice in succession, and the quality of the latest position information is determined from the position information of the past two times (the previous time and the previous time). However, depending on the situation where the position information is measured, there is no possibility that the wrong position is erroneously detected a plurality of times. Therefore, the pass / fail determination may be performed using past position information for three or more times depending on the positioning situation.

In the present embodiment, the mobile terminal 1 in the monitoring mode is detected to move and output an abnormal signal. However, the present invention is not limited to this. The movement to the area may be detected based on the position information and an abnormal signal may be output. In this case, the movement determination unit 19 determines the movement to the movement prohibited area based on the position information determined to be OK by the pass / fail determination unit 18.

Furthermore, in the present embodiment, the mobile terminal 1 determines whether the position information is good or not, and determines whether or not there is movement. However, these processes may be performed by the center device 3.
In this case, the center device 3 is provided with the pass / fail determination unit 18 and the movement determination unit 19 included in the mobile terminal 1 in the present embodiment. When the mobile terminal 1 is set to the monitoring mode by the setting operation of the operation unit 14, the mobile terminal 1 transmits a monitoring setting signal to the center device 3, and thereafter transmits position information to the center device 3 every predetermined time. When the center device 3 receives the monitoring setting signal from the portable terminal 1, the center device 3 starts monitoring the position of the portable terminal 1, determines whether the received position information is good, and moves the portable terminal 1 according to the position information that is normally measured. Monitor for the presence or absence of When the center device 3 receives a release signal based on the release operation of the operation unit 14 from the mobile terminal 1, the center device 3 ends the monitoring of the mobile terminal 1.

The figure which shows the whole structure of the positional infomation monitoring system of this invention The figure which shows the functional block of the portable terminal The figure which shows the functional block of the center device Diagram showing position table Flowchart showing position information pass / fail judgment operation The schematic diagram which shows the mutual relationship of the positional information AD in the position table shown by FIG. Flow chart showing movement determination operation of portable terminal Schematic diagram showing the correlation between error ranges

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mobile terminal 2 ... Monitoring center 3 ... Center apparatus 4 ... Mobile telephone base station 5 ... Communication network 6 ... GPS satellite

Claims (3)

A position information monitoring system for monitoring position information of a moving body and determining movement of the moving body based on a change in the position information,
A position detector for acquiring position information;
A position storage unit that stores position information acquired by the position detection unit;
A pass / fail determination unit that compares the latest position information with past position information and determines the pass / fail of the latest position information based on the distance between points indicated by each position information;
A movement determination unit that determines the movement of the moving body based on the position information determined to be good by the determination unit;
A position information monitoring system comprising:
The pass / fail judgment unit compares the latest position information with the past position information, and if the latest position information is determined to be negative, the latest position information is different from the past position information. The position information monitoring system according to claim 1, wherein the latest position information is judged again and again in comparison with the position information acquired at the time.
In addition, a monitoring setting means for setting the monitoring operation of the position information to start and stop is provided,
The movement determination unit stores position information when the monitoring operation is started and set by the monitoring setting unit in the position storage unit, and then monitors position information determined to be good by the pass / fail determination unit. The position information monitoring according to claim 1 or 2, wherein when the position information determined to be good is separated from the position information at the start of the monitoring operation by a predetermined distance or more, the movement of the moving body is determined and an abnormal signal is output. system.

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