JP2004061336A - Positioning method and positioning terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning method and a positioning terminal for easily reducing a time required until positioning when the positioning begins although a structure has a function other than a positioning function. <P>SOLUTION: A portable information terminal 1 has the GPS positioning function. When the portable information terminal 1 is at a cold start or a warm start, the portable information terminal 1 implements the positioning by using only power supplied to a GPS block 7, switches to a sleep mode for halting operation of a terminal apparatus block 6 including a CPU 14 except for a timer function part 17 until effective almanac and ephemeris (satellite information) are acquired, periodically generates an activation signal (a) from the timer function part 17, periodically activates the CPU 14, periodically releases the sleep mode and makes the CPU 14 confirm whether the effective satellite information is acquired. The generation of undesired electromagnetic wave radiation can be suppressed only while the satellite information is acquired. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a positioning method in a positioning terminal that performs radio wave positioning of a current position, and a positioning terminal.
[0002]
[Prior art]
Currently, a GPS (Global Positioning System) function of receiving radio waves from a plurality of satellites and positioning the current position by radio waves, that is, a terminal device (hereinafter, a positioning terminal) having a GPS positioning function has been put to practical use. Among such terminal devices, those having a GPS function incorporated in advance include, for example, a car navigation system and a wristwatch type having a clock function. In recent years, even a portable information terminal such as a notebook type, which has been rapidly spreading, has a GPS circuit built-in or a CF (compact flash I / F) type option card incorporating a GPS circuit. For example, a GPS function can be added, and such a portable information terminal allows a user to easily know the current position.
[0003]
On the other hand, the positioning method using the GPS includes a single positioning method for calculating the current position from satellite information received independently and a relative information sent from a base station that always receives satellite information, and quickly obtains satellite information. There is a differential method for performing reception processing.
It is necessary to receive radio waves from four or more satellites in order to perform accurate positioning using the single positioning method. To calculate latitude and longitude from the received radio wave information, time correction information, orbit information (ephemeris information) ), Satellite information (almanac), ionospheric correction data, etc. are required as initial information. Generally, these initial information are stored at the time of positioning and are referred to at the next positioning.However, since the initial information may not be stored at the time of positioning or may become invalid over time, it is usually At the beginning, positioning is performed in the following operation modes depending on the state of the initial information.
1) Hot start: almanac valid / ephemeris valid 2) Warm start: almanac valid / ephemeris invalid 3) Cold start: almanac invalid / ephemeris invalid
The time required for positioning in each operation mode is as follows: (1) Hot start, several seconds to several tens of seconds, (2) Warm start, when the satellite is in a visible state and the influence of noise such as unnecessary radiated radio waves is not considered. It takes several tens seconds to several minutes, and (3) several minutes to several ten minutes for cold start.
[0005]
[Problems to be solved by the invention]
However, in the above-mentioned positioning terminals, in electronic devices such as a wristwatch type or a portable information terminal, which are required to be miniaturized, it is difficult to take thorough measures against the effects of unnecessary radiation waves and power supply noise. This is because it leads to performance degradation of other functions other than the positioning function and an increase in the cost of the apparatus. On the other hand, the influence of unnecessary radiated radio waves and the like is easily received during the warm start and the cold start until both the almanac and the ephemeris become effective, which is a factor of deteriorating the satellite tracking sensitivity. For this reason, in a positioning terminal having a function other than the positioning function and required to be miniaturized, it takes a long time to acquire a satellite at the beginning of positioning and to calculate latitude and longitude. There was no problem.
[0006]
The present invention has been made in view of such a conventional problem, and even in a configuration having functions other than the positioning function, a positioning method that can easily shorten the time required for positioning at the beginning of positioning. , And a positioning terminal.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, according to the present invention, a positioning terminal having a positioning function of receiving a radio wave transmitted from a satellite and calculating a current position, and another function other than the positioning function. In the method, when valid satellite information is not held when positioning is started, the operation related to the other function is suspended.
[0008]
According to such a method, when valid satellite information is not held at the time of starting positioning, by suspending operations related to functions other than the positioning function, while newly acquiring satellite information, Generation of unnecessary radiation waves due to operations related to other functions is suppressed, and high satellite tracking sensitivity can be secured.
[0009]
Further, according to the invention of claim 2, a positioning terminal which receives a radio wave transmitted from a satellite to calculate a current position and has a function other than the positioning function is provided. Storage means for storing the satellite information obtained from the satellite, and with the start of positioning by the positioning means, confirms whether or not valid storage information is stored in the storage means, and holds the valid satellite information. If not, control means for suspending the predetermined operation related to the other function is provided.
[0010]
In such a configuration, when valid satellite information is not held in the storage unit at the start of positioning, the control unit suspends a predetermined operation related to a function other than the positioning function based on the operation of the positioning unit. . Therefore, while newly acquiring the satellite information, the generation of unnecessary radiated radio waves due to the operation related to other functions is suppressed, and a high satellite tracking sensitivity can be secured.
[0011]
Further, in the invention according to claim 3, when the valid satellite information is not held, the control means intermittently checks whether new satellite information has been acquired from the satellite by the positioning means. At the same time, predetermined operations relating to the other functions are suspended until it is confirmed that new satellite information has been acquired.
[0012]
In such a configuration, by intermittently confirming whether or not new satellite information has been acquired, unnecessary radiated radio waves accompanying operations related to functions other than the positioning function are obtained until new satellite information is acquired. Can be further suppressed, and a higher satellite tracking sensitivity can be secured during that time.
[0013]
Further, in the invention according to claim 4, the control unit includes an activation unit that suspends an operation related to the other function including its own operation, and intermittently activates the control unit in a suspended state. In addition, each time the control means is activated by the activation means, the control means confirms whether or not new satellite information has been acquired from the satellite by the positioning means.
[0014]
In such a configuration, until new satellite information is acquired, generation of unnecessary radiated radio waves due to operations related to functions other than the positioning function can be further suppressed, and a higher satellite tracking sensitivity is secured during that time. be able to.
[0015]
In the invention of claim 5, the satellite information is ephemeris information and / or almanac information.
[0016]
Further, according to the invention of claim 6, a computer having a positioning terminal having a function other than the positioning function, including positioning means for receiving a radio wave transmitted from a satellite to calculate a current position, With the start of positioning by the positioning means, it is checked whether or not valid satellite information is held, and if valid satellite information is not held, the predetermined operation relating to the other function is suspended. The program was made to function as control means.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing a portable information terminal 1 which is a positioning terminal of the present invention. The portable information terminal 1 has a general structure in which a liquid crystal display 3 and a plurality of operation keys 4a to 4d are provided on an upper surface of a notebook-sized main body 2, and a GPS circuit 5 is built in the main body 2. ing.
[0018]
FIG. 2 is a block diagram showing an electric configuration of the portable information terminal 1. The portable information terminal 1 is a terminal mainly for implementing functions as an information terminal such as business card management, schedule management, dictionary, and memo pad. It comprises a device block 6 and a GPS block 7 corresponding to the GPS circuit 5 for realizing a GPS positioning function.
[0019]
The terminal device block 6 mainly includes a system LSI 11, a display unit 12 including the liquid crystal display 3 and its driving circuit, an input unit 13 including the operation keys 4a to 4d, a CPU 14 for controlling the system LSI 11, a ROM 15, a RAM 16, a timer. It comprises a functional unit 17. The ROM 15 stores programs and data necessary for the CPU 14 to control the entire apparatus. The program is a program necessary for controlling the entire portable information terminal 1 and a program for realizing various functions as an information terminal such as the business card management described above. Then, the CPU 14 functions as the control means of the present invention by operating based on the program stored in the ROM 15. The RAM 16 is a working memory for the CPU 14 and the system LSI 11. The timer function unit 17 is a circuit that generates an interrupt signal a at every time set in advance by the CPU 14 in a sleep mode described later, and activates the CPU 14 in the sleep state by the interrupt signal a. Thus, the activation means of the present invention is realized.
[0020]
The GPS block 7 includes a GPS function unit 22 connected to the system LSI 11, an antenna unit 21, and an internal storage unit 23. The antenna unit 21 includes a GPS antenna that receives L1 band radio waves from GPS satellites, an RF, an A / D, and the like. The GPS function unit 22 is a positioning means of the present invention. The GPS function unit 22 is a data register and a radio signal necessary for decoding positioning information including ephemeris and almanac (satellite information) and C / L code from radio waves received by the antenna unit 21. It is composed of a counter that counts the time with the accuracy of an atomic clock to obtain the reception timing, a decoder, a clock circuit, and a signal processing unit that controls them. Then, the GPS function unit 22 receives a radio wave from a GPS satellite only by power supply without requiring the control of the CPU 14, and calculates a current position (latitude / longitude) based on the decoded C / L code, The result is output to the system LSI 11. The internal storage unit 23 is a storage unit of the present invention, and is constituted by an SRAM or the like capable of holding stored data except for battery replacement. The internal storage unit 23 is acquired from a GPS satellite by the GPS function unit 22 and has a current position (latitude / It stores ephemeris and almanac, time correction information, and ionospheric correction data used for capturing satellites and the like prior to calculation of longitude.
[0021]
Next, the operation of the portable information terminal 1 having the above configuration relating to GPS positioning will be described with reference to the flowchart of FIG.
[0022]
The portable information terminal 1 supplies power to the GPS block 7 in response to, for example, a predetermined key operation by the user to start GPS positioning, and initializes almanac information stored in the internal storage unit 23, that is, the previous positioning. It is determined whether or not the almanac used for is valid (step S1). At this time, if the almanac is invalid (NO in step S1), a predetermined time is set as a timer interrupt cycle (cycle for generating an interrupt signal a) in the timer function unit 17 (step S2), and then the timer function unit 17 is removed. Then, a sleep mode for turning off the power of each unit of the terminal device block 6 including the CPU 14 is set (step S3).
[0023]
Thereafter, each time the timer interrupt timing comes, that is, each time the timer function unit 17 generates the interrupt signal a (YES in step S4), the sleep mode is released once (step S5) and stored in the internal storage unit 23. Then, it is determined whether or not the almanac being performed is valid (step S6). That is, even in the sleep mode state, the GPS function unit 22 performs a positioning operation for acquiring the latest almanac, that is, an operation of searching for a GPS satellite that can receive radio waves and acquiring (collecting) an almanac from the searched GPS satellite. And periodically check whether it has been obtained. If the almanac is not valid (NO in step S6), the sleep mode is set again, the sleep mode is periodically released, and the operation of determining whether the almanac is valid is repeated (step S3). ~ S6). Thereafter, if the almanac becomes valid at any of the timer interrupt timings (YES in step S6), the ephemeris initial information stored in the internal storage unit 23, that is, the ephemeris used for the previous positioning is continuously obtained. It is determined whether or not is valid (step S7). If the almanac is valid at the beginning of the positioning (YES in step S1), the determination in step S7 is immediately performed.
[0024]
Here, if the ephemeris is invalid (NO in step S7), a predetermined time is set as a timer interrupt cycle in the timer function unit 17 (step S8), and the sleep mode described above is set (step S9). Thereafter, every time the timer interrupt timing arrives, that is, each time the timer function unit 17 generates the interrupt signal a (YES in step S10), the sleep mode is released once (step S11) and stored in the internal storage unit 23. It is determined whether or not the ephemeris that has been performed is valid (step S12). That is, even in the sleep mode state, the GPS function unit 22 performs a positioning operation for acquiring the latest ephemeris, that is, an operation for acquiring the latest ephemeris from each GPS satellite acquired based on the latest almanac, and the acquisition is performed. Periodically check whether or not it was completed.
[0025]
If the ephemeris is not valid (NO in step S12), the sleep mode is set again, the sleep mode is periodically released, and the operation of determining whether the ephemeris is valid is repeated (step S12). Steps S9 to S12). Thereafter, if ephemeris becomes valid at any of the timer interrupt timings (YES in step S12), the latitude and longitude are calculated, and both the latest almanac and ephemeris acquired in the above-described processing or the latest ephemeris is obtained. It is updated and stored in the internal storage unit 23 as initial information (step S13). Here, the calculated latitude and longitude are displayed on the liquid crystal display 3. When the positioning is completed by finishing the calculation of the latitude / longitude (YES in step S14), the positioning processing is ended. If both almanac and ephemeris are valid at the beginning of the positioning (YES in step S7), the process immediately proceeds to step S13 to calculate the latitude and longitude.
[0026]
In the above-described operation, the determination of the validity / invalidity of the almanac in step S1 and the determination of the validity / invalidity of the ephemeris in step S7 are performed, for example, when the latest almanac or ephemeris is acquired, and the time information ( The date (including the date) is stored in the internal storage unit 23 or the like of the GPS block 7 and determined according to a valid period (eg, about three months for almanac and about four hours for ephemeris) from that point on. This is performed by determining whether or not a predetermined period has passed. The timer interrupt cycle set in the timer function unit 17 in the processing of the above-described steps S2 and S8 is a time normally required for acquiring almanac and ephemeris in a state where a GPS satellite is captured (about 13 minutes in the former, about the latter in the latter). This time is about 30 seconds).
[0027]
As described above, in the present embodiment, at the time of a cold start in which almanac and ephemeris are invalid at the start of positioning, the sleep mode is entered until a valid almanac and ephemeris can be obtained, and only ephemeris is invalid at the start of positioning. In the warm start, the sleep mode is entered until a valid ephemeris can be obtained. In the sleep mode, it is periodically checked whether a valid almanac or ephemeris has been obtained. For this reason, until the almanac or ephemeris is acquired, that is, until the satellite is captured and the latitude and longitude can be calculated, the generation of unnecessary radiated radio waves from the terminal device block 6 is negligible. In the meantime, a high satellite tracking sensitivity can be secured.
[0028]
Therefore, even if the configuration has a function other than the positioning terminal in the GPS, the time required until the current position can be calculated at the start of the positioning by the cold start or the warm start, which is easily affected by the unnecessary radiated radio wave, is reduced. Shortening is easily possible. Moreover, since it is not necessary to take thorough measures against the effects of unnecessary radiation waves and power supply noise, the above effects can be obtained without deteriorating the performance of functions other than the positioning function or incurring unnecessary costs. Becomes possible. In particular, it is very effective in an electronic device that requires a small size in which it is difficult to take measures against noise such as a shield in terms of space.
[0029]
In the present embodiment, the power of each unit of the terminal device block 6 including the CPU 14 is turned off during the operation in the sleep mode described above. However, the CPU 14 is turned off while the power is supplied to each unit. A configuration may be adopted in which only the operation of each unit including the above is suspended. In this case as well, since the generation of unnecessary radiated radio waves due to the operation of each unit can be suppressed, the current position can be calculated by a cold start or a warm start which is easily affected by the unnecessary radiated radio waves as in the present embodiment. It becomes possible to shorten the time required until the operation becomes possible. Furthermore, the operation of only a specific circuit or device that is a source of unnecessary radiated radio waves, which is different depending on the circuit of the terminal device block 6 and the arrangement of each device but has a large influence on the positioning operation of the GPS function unit 22, is suspended. Or the power may be turned off.
[0030]
In addition, the sleep mode described above is periodically released to check whether the latest almanac or the latest ephemeris (satellite information), which is the initial information necessary for calculating the latitude and longitude, has been obtained. The following may be performed. That is, as described above, it takes about 13 minutes to acquire an almanac while acquiring a GPS satellite, and about 30 seconds to acquire an ephemeris. Therefore, for example, the timer interrupt cycle set in the timer function unit 17 in step S2 described above is set to about 13 minutes + α (α is arbitrary) for the first time, and a shorter time for the second and subsequent times. Similarly, the timer interruption period set in the timer function unit 17 in step S8 is set to 30 seconds + α for the first time, and shorter for the second and subsequent times. In other words, the sleep mode release cycle may be set shorter for the second and subsequent times than for the first time, and intermittently checking whether the latest almanac or the latest ephemeris has been obtained. In such a case, after entering the sleep mode, the number of times the sleep mode is canceled before the latest almanac or the latest ephemeris is acquired can be minimized, and the GPS function unit can be set within that period. It is possible to further reduce the influence of unnecessary radiated radio waves on the positioning operation of No. 22.
[0031]
Further, for example, an LED that lights when the apparatus is in the sleep mode described above may be provided, and the user may be notified by turning on the LED that valid satellite information is being acquired. In that case, the user can know the operation state, and the usability is improved. Also, when a predetermined key operation is performed by the user during the sleep mode, the CPU 14 is activated at that time to release the sleep mode, and thereafter, the normal positioning operation without setting the sleep mode is performed. You may do so. In this case, even after the start of the positioning, the function as the information terminal described above other than the positioning function can be used immediately, so that the usability is improved. In addition, a positioning mode with operation in the sleep mode described above and a normal positioning mode are prepared as the positioning mode, and the user can select which positioning mode to execute positioning prior to starting position measurement. It may be configured.
[0032]
Further, in the present embodiment, the portable information terminal 1 in which the GPS circuit 5 is built in the main body 2 is shown as the positioning terminal of the present invention, but other than this, for example, other portable information terminals shown in FIG. Even if the configuration is such that a GPS (Compact Flash I / F) type option card 53 in which the GPS circuit 5 is incorporated is attached to the main body 52 as required, a GPS function can be added as required. Can be adopted. In this case, however, it is necessary to provide a circuit equivalent to the timer function unit 17 in the portable information terminal 51 in advance, or to provide the same in the option card 53. Further, the present invention can be applied to a case where a GPS circuit is incorporated in an electronic device other than the portable information terminal, for example, a digital camera, a mobile phone, a wristwatch, or the like to have a positioning function. This is extremely effective especially when the location of the GPS circuit is limited when the product is downsized.
[0033]
【The invention's effect】
As described above, according to the first and second aspects of the present invention, when valid satellite information is not held at the time of starting positioning, generation of unnecessary radiated radio waves due to operations related to functions other than the positioning function is suppressed. By doing so, high satellite tracking sensitivity can be secured. Therefore, even in a configuration having functions other than the positioning function, the time required for positioning at the beginning of positioning can be easily reduced without deteriorating the performance of other functions other than the positioning function or increasing the cost more than necessary. It can be shortened.
[0034]
Further, in the invention of claim 3, generation of unnecessary radiated radio waves due to operations related to functions other than the positioning function can be further suppressed before newly acquiring satellite information, and higher satellite tracking sensitivity can be obtained during that time. Can be secured. Therefore, the above effect can be made remarkable.
[0035]
Further, in the invention of claim 4, generation of unnecessary radiated radio waves due to operation related to functions other than the positioning function can be further suppressed, and higher satellite tracking sensitivity can be secured during that time. Therefore, the above effect can be further remarkable.
[Brief description of the drawings]
FIG. 1 is an external view of a portable information terminal according to an embodiment of the present invention.
FIG. 2 is a block diagram of the portable information terminal.
FIG. 3 is a flowchart showing an operation relating to GPS positioning in the embodiment.
FIG. 4 is an external view showing another portable information terminal having a GPS function.
[Explanation of symbols]
1 portable information terminal 5 GPS circuit 6 terminal device block 7 GPS block 14 CPU
15 ROM
17 Timer function unit 22 GPS function unit 23 Internal storage unit

Claims (6)

A positioning method for a positioning terminal having a positioning function of calculating a current position by receiving radio waves transmitted from a satellite and other functions, and when starting positioning, valid satellite information is held. If the operation has not been performed, the operation related to the other function is suspended. A positioning terminal that receives a radio wave transmitted from a satellite and calculates a current position, and has a function other than the positioning function,
Storage means for storing satellite information obtained from the satellite by the positioning means,
With the start of the positioning by the positioning means, it is checked whether or not valid satellite information is held in the storage means.If the valid satellite information is not held, the predetermined information relating to the other function is determined. A positioning terminal, comprising: control means for suspending operation. When the valid satellite information is not held, the control unit intermittently checks whether or not new satellite information has been acquired from the satellite by the positioning unit, and that the new satellite information has been acquired. 3. The positioning terminal according to claim 2, wherein a predetermined operation related to the other function is suspended until a confirmation can be made. The control unit includes an activation unit that suspends an operation related to the other function including its own operation, and intermittently activates the control unit in a suspended state, and the control unit is activated by the activation unit. The positioning terminal according to claim 3, wherein each time the positioning unit checks whether new satellite information has been acquired from the satellite by the positioning unit. The positioning terminal according to claim 2, wherein the satellite information is ephemeris information and / or almanac information. A computer having a positioning terminal having a function other than the positioning function, including positioning means for calculating a current position by receiving a radio wave transmitted from a satellite,
With the start of positioning by the positioning means, it is checked whether or not valid satellite information is held, and if valid satellite information is not held, the predetermined operation relating to the other function is suspended. A program that functions as control means.

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