JPS63118687A - Timepiece - Google Patents

Abstract

PURPOSE:To display accurate time and position by adding a global positioning system (GPS) receiver, the function of a processor where a position measurement calculating device and a normal clock part are combined and controlled, etc. CONSTITUTION:A GPS receiver 1 and the function of a processor 2 where the measurement position calculating device and the normal clock part are combined and controlled are added to this clock. An input terminal 8 is attached to designate whether the position measurement processing or the normal clock function is executed, and the processing flow is so controlled that the operation in the designated processing mode is possible, thereby combining two parts, namely, the clock part and the position measuring part different in function. The GPS receiver 1 uses the GPS standard time, and the normal clock uses a local time. The difference between these times is taken into consideration as the clock. Two accumulator 5 are prepared for local time and GPS standard time, and the conversion function between two times is provided, and data required for position measurement is stored in a memory 9 and is rewritten on demand. Thus, accurate time and position are displayed on a display device.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention is directed to timepieces that measure time, such as wristwatches, and have a GPS reception function within the watch. This makes it possible to measure time and position. [Conventional technology] In recent years, GP systems that measure one's position using satellite radio waves have been introduced.
S Global Positioning System: (Glo
bal Positioning System) is being developed. In the 1990s, more than 18 GPS satellites were launched, and more than five satellites were visible all over the world at any given time. Therefore, with a GPS receiver and a processing device for position calculation, highly accurate position determination is now possible all over the world. On the other hand, there is a need to accurately know one's position when climbing a mountain, etc., and a positioning watch is desired. In addition, as the above-mentioned GPS-related documents, for example, Document 1:
"The G-Pinis Navigation Message, Navigation Volume 25. No. 2, pp. 147-165, 1978 (The G
PS Navigation Message. Navigation Vo fl 25, Na
2) J.R. Reference 2: “A Position Fixing, Algorithm for the Low-Cost G-Binis Receiver, A Pa5ition Fixin
gAlgorithm for the Low Co
5t GPS Receiver, IEEE Tran
s, on AES) March 1976. [Problems to be Solved by the Invention] However, GPS receivers are designed to measure the position of moving objects, and this function is built into a portable timepiece such as a wristwatch. In order to perform the position calculation function at certain times, it is necessary to (i) store the satellite data necessary for receiving GPS signals;
) A method for correcting the time correction amount when calculating a position using a GPS signal (2) There are many problems to be solved such as a method for displaying time data and position data.
A reception function is built into the watch. To provide a clock that can display accurate time and position.

[Means to solve the problem]

In the present invention, a processing device function for combining and controlling a GPS receiver and a side calculation device with a normal clock part is added,
By attaching an input terminal to specify whether to perform positioning processing or normal clock function, and controlling the processing flow so that the chair can operate in the estimated processing mode, the two parts of the clock and positioning, which have different functions, can be combined. made it possible to combine. Furthermore, GPS uses GPS standard time, and a normal clock uses local time. The difference between these two must be taken into account when using a watch. So, for local time and GPSII! Two accumulators were prepared, one for l1111 time, and a conversion function between the two times was provided to correspond between GPS time and local time. In addition, the data necessary for positioning is not stored in memory, but can be rewritten as needed. In this way, the desired function was achieved by adding a control device that combines and controls the GPS positioning function and the normal clock function. Details will be explained below in Examples. [Example] Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram of hardware constituting a timepiece according to the present invention. The part indicated by the broken line is the hardware included in a conventional GPS receiver. An overview of the operation of the system shown in FIG. 1 is as follows. The GPS signal receiver 1 receives a signal containing navigation data from the GPS and decodes it. Navigation data included in the GPS signal is extracted from the specifications regarding the content of the GPS signal (Reference 1). FIG. 2 shows the configuration of the GPS receiver. GPS receivers can range from 1 channel to 4 channels, but here we will consider a 4 channel receiver that can receive radio waves from 4 satellites at the same time, but even 1 channel and 2 channel receivers will have a slight difference. There are some changes, but the essence remains the same. In FIG. 2, radio waves from each satellite are received by an antenna, and carrier waves of the radio waves from four satellites selected by a processing device 2 are removed by a band pass filter 13 to extract a digital signal. A pseudorandom code is added to this digital signal, and navigation data is extracted by a synchronization circuit 14 using a pseudorandom code corresponding to the selected satellite and stored in a buffer 15. The reception time is given by adding the contents of an accumulator indicating a time to each pulse of the digital signal. That is, receiver 1
In the output, navigation data from GPS*M according to the above (Reference 1) is extracted. The processing device 2 uses an algorithm based on the position determination method of a normal GPS positioning system. FIG. 3 shows a flowchart of the processing performed by the processing device 2. First, when a positioning calculation command is input from an input terminal to the processing device 7, the processing device 7 starts the processing device 2. The activated processing device 2 first reads the orbital elements of the GPS satellites from the memory 9, and calculates the satellite position at the current time based on the time in the register 5 indicating the current time. The current position of the satellite is calculated from the orbital elements based on the definition of GPS navigation data (Reference 1). This GPS receiver uses 4 channels for satellite reception, and as will be described later. Receiving position (X, Y, Z), GPS time managed by the GPS system, and internal clock (e.g. crystal oscillator)
The four parameters, ie, the time difference ΔT from the time created by the accumulator 5, are unknown parameters in the GPS navigation calculation. Therefore, it is necessary to select four GPS satellites for navigation calculations. For this reason, conventionally, in the field of positioning theory, G D OP (Geometry
Satellites were selected using an evaluation standard called ``c Dilution of Precision''. G
When the unit vector from the user receiver position to the GPS satellite i is defined as (al. bI, at ), DOP is calculated as (HT
It is defined as OP=ff shoulder positive 1=...(2). To calculate this, we need the position of each satellite and a priori position information of the receiver. Based on the altitude of GPS@971 and the literature published so far regarding the evaluation of the influence of initial error, it is thought that the influence of initial error is not very large in Japan, and a priori position information is based on the previous Use the calculated reception position. Therefore, in processing block A, the reception position (Xo,
YO, ZO) will also be read. This (Xo y
First, xo(xsI-xo)+yocyss-yo)+zo(
xsI-zo)>cosθO...(3) Extract those that satisfy the following. For example, θ0 is the inclination angle of 10°
If the above satellites can be received, θ0=90@-10
Set °=80°. Next, for the satellites extracted as receivable, a unit direction vector (az, bt
HCt). Furthermore, four GPS satellites are selected using the GDOP evaluation criteria. In other words, since GDOP corresponds to the prediction estimation error, the four satellites that minimize it are selected, but since equation (2) includes inverse matrix calculation, as an alternative norm, 4 satellites are selected.
A rule is taken to maximize the volume of the square pyramid formed by the three GPS*ffi and the receiver position given a priori. This is equivalent to choosing the one that maximizes (4). Furthermore, detH=axas+bxax+asas-β o(
5) If transformed as β:a4αl+b4α2+C4α8, then if the satellite to be replaced is (ax, bz. OL), then equation (5) can be evaluated. In this way, the satellite selection process can be simplified, making it suitable for microcomputer processing. Table 1 shows the simulation results when (5) is used instead of (2). In this way, it can be seen that even if the evaluation criterion is changed to Equation (5), there is not much difference in the satellite selection results. (Processing block B) Clear dimension 4ゝゝゝ～ゝゞゞゞ: F2 MF'
+C%liゞCn ++1 +-1--P-1-The Doppler characteristics for the selected satellite are calculated and transferred to the receiving device 1. Now, as already explained, when the receiving device 1 extracts the navigation data from the GPS and stores it in the buffer 15, the processing device 2 reads out the navigation data from each GPS.
The satellite position is in the inertial coordinate system (Xlt 'is t Zt
), the signal transmission time is GPS standard time, tst, and the signal reception time is the receiver clock, given by tr, then (xt-x)"+(3'+-y)2L+(zi-z)"
=c(tsz-tr+b)+n+...(6) Obtain four observation equations of the form. In processing block D,
The unknown quantity (X+ytZ'+b) in the above equation is linearized using the a priori position information of the receiving position, and estimated using the JX square method as follows. b is the difference between the time according to the receiver's clock and the GPS standard time. calculated (Xy Yr
Zt')) is transferred to a register and then to memory. Register 3 contains the calculated user position (x, y, z
), register 4 is a register that stores GPS
It is used to store the time difference. Further, necessary data such as reception position results are stored in the memory 9. - When the calculation process is completed, the processing device 3 checks the status MA monitoring flag in the processing device 7 to determine whether to continue the positioning calculation process. If the end flag is ON, the process ends; otherwise, the process continues. At this time, the a priori reception position (xo + y
o , zo ) and newly obtained (X+ y+
If the distance of z) is greater than the tolerance value E, it is necessary to reselect the GPS satellite, in which case processing will continue from processing block B. Next, the functions of the processing device 7, which performs various controls to perform the function of the watch, which is the most important feature of the present invention, will be explained. FIG. 4 conceptually illustrates the necessary functions of the processing device 7. The function required by the processing device 7 is an input function. Data conversion, status monitoring 2 display function, processing flow control 5
It has a processing function as shown in Fig. 4. It is essential as a clock function. In order to realize these functions, the hardware configuration of the processing device 7 is shown in FIG. The contents of the processing device 7 will be specifically explained below with reference to FIG. First, the specific contents of the necessary processing functions shown in FIG. 4 and the operation of the hardware shown in FIG. 5 will be explained. First, regarding the input function, the input terminal 16 is used to change the processing mode, and by pressing it, the registers 19 such as Al, A2, A3, etc. One of A4 is turned on (bit becomes 1), where, for example,
Al, A2. , A3° and A4 processing modes are defined as follows. A1: Normal watch mode A2: Positioning measurement and time error calculation mode using GPS radio waves A3: Time correction mode A4: Memory content change mode Next, the input terminal 17 is used to select the memory content change mode or 1 time correction mode. This is an input terminal to a register 20 that specifies which memory contents are to be changed. For example, Bl, . . . , BN may be considered as addresses in the memory where data to be changed is stored. Further, the input terminal 18 is an input terminal for changing contents, that is, numerical information, and the register 21 represents the numerical contents. Processing for each processing mode is performed as follows. (i) Normal clock mode It is assumed that the local time contents are stored in the time accumulator 23. Furthermore, the contents of the accumulator 213 are divided into four parts, 2 minutes, 9 seconds and 2 seconds, as in a normal clock, as shown in Figure 6.
Minutes and 2 seconds are rounded up in base 24, base 60, and base 60, respectively. Register 1 via CPU22
9 A1 signal is transmitted to the determination circuit 26, and the display bag [
At 28, the time accumulator 23 indicates 9 minutes. seconds, the contents of the register are output. The content output to the display screen is the same as that of a normal watch, as shown in FIG. 7(a). (ii) When the contents of GPSfW, wave-based positioning and time correction mode A2 are turned ON, the CPU 22 (EPS
The positioning calculation processing device 2 is activated. The processing contents of the processing device 2 have already been described. When one positioning process is completed, the process results are stored in registers 3 and 4 in FIG. The contents of register 3 relate to the calculated user position, which is the x, y, z values in the inertial coordinate system. In order for the user to know his/her own position by displaying it, it is necessary to display it as at least 2 minutes and 2 seconds of latitude and longitude. That is, CPU2
In step 2, the contents of register 3 and register 4 are read out and the position is calculated as follows. First, calculate the elapsed time since Greenwich O'clock. This is based on the reception time tr and the time correction value Δt included in register 3, j ” t r+Δt . . .
Calculate (7) and calculate t, = tmod 86400 ・=
In (8), calculate the elapsed time from Grietsu 0:00. By storing the earth's rotational angular velocity ω in the CPU,...(9
) to convert to values in the earth-fixed coordinate system. Further latitude η
, longitude ξ in Z' and convert η and ξ from radians to degrees 1 minute 9 seconds. Furthermore, the result is stored in the register 24. Next, correction regarding time is performed. Regarding time, the accumulator 5 stores the Greenwich time from the beginning of the week corresponding to the GPS time, and the accumulator 23 stores the contents of the local time corresponding to the contents of the accumulator 5. The CPU 22 adds the time correction amount in the register 4 to the accumulators 5 and 23 to update the contents. Further, the content display in this processing mode is numerical information regarding longitude and latitude in the register 24, an example of which is shown in FIG. 7(b). (ni) Time correction mode With a watch that combines a GPS receiver and a watch according to the present invention, it is possible to correct the difference between Greenwich Mean Time on the watch side and the GPS time, but normally, the time difference when traveling to different parts of the world can be corrected. The time correction is due to. Requires human judgment. For this reason, the timepiece according to the present invention also has a time correction function for this purpose. When A3 is in the ON state, it is in time correction mode,
There are cases in which the object of correction is only the local time, and cases in which the original time, that is, the contents of the accumulator 5 are changed. This specification is made by input terminal 17 in register 2.
Indicated by the content of 0. For example, assume that the register 20 specifies a change in the time term of local time. At this time, the current contents to be changed are displayed as shown in FIG. 7(c). Sections to be changed are marked with a change mark (). The number input from the input terminal 18 is changed to the specified value in the register 24, and the changed contents are displayed. A positive number for input. A negative number is required, and when the input terminal 18 is pressed, a positive number,
It is designed so that when you subtract it, a negative number is input. When changing the contents of the accumulator 5, the CPU 22 first converts it into the format of hours 2 minutes 9 seconds as shown in FIG. Correct. In this case, the corrected hours, minutes, and seconds are converted into data for the beginning of the week in Greenwich Mean Time and transferred to the accumulator 5. (iv) When the memory content change mode A4 is turned on, the content of the memory 9 is changed. The memory 9 stores orbit data of GPS satellites and the like necessary for capturing GPS radio waves and performing positioning calculations. For example, the memory format in memory 9 is given as shown in FIG. The data in the memory 9 specified by the contents (address) of the register 20 is sent to the register 25 and displayed on the display device 28. Input terminal 1
According to the input result of step 8, the contents of register 25 are changed,
It is output to the display device 28. When the modification is completed, the contents of register 25 are transferred to the corresponding address in memory. The four processing modes have been described above, but the CPU 22
Now, how do you end processing modes other than A1? It is determined that each processing mode has been terminated when the state shifts to A1, that is, the normal clock mode, by input through the input terminal 16. Through the above explanation, the input function data conversion function 2 display function shown in FIG. 4 has been explained. Among the functions shown in FIG. 4, status monitoring and processing control will be described below. First, the status monitoring function will be explained. The register 27 in FIG. 5 is a status display register, and if there is an abnormality in the monitoring result of the internal status, it is notified by setting bits It I I+. For example, to explain the case of indicating whether or not the power within one clock is sufficient, in FIG. An abnormality flag is set in the corresponding part of 27. If there is an abnormality in the register 27, it is displayed as an alarm signal on the display surface of the clock. FIG. 7(a) shows an example of outputting an alarm signal. Furthermore, regarding the memory 9, a nonvolatile and rewritable memory (for example, bubble memory, etc.) is used even when there is no power supply. By integrating the individual processes described above, the CPU 22
6, which forms one processing control flow, is shown in Fig. 9.
An example of a flow for controlling each processing mode is shown. In normal clock mode, the clock signal is sent to accumulator 2.
3 is added and only displayed, with almost no CPU intervention. In this mode, a timer interrupt is generated at regular intervals to check the contents of the status display register 27! Checks the monitoring and processing mode registers. Processing mode register A1 is off (OFF)
The normal clock mode continues until it is determined that this is the case. Furthermore, A2. A3. Even if the mode shifts to A4 processing mode, the time is updated by the clock, that is, the contents of the accumulator 23 and the accumulator 5 are always updated. If the processing mode register check selects a processing mode other than clock mode. Perform the corresponding series of processing mode processing and try again. Check processing mode. If the processing mode is A1,
Resume normal clock mode. If it is not A1, continue the specified processing mode. Note that since the specific contents of each processing mode have already been described, they will be omitted here. As described above, a system can be constructed that can realize a clock that has both a positioning calculation function using GPS radio waves and a normal clock function. The timepiece according to the present invention requires more electronic related devices such as LSI and antennas than a normal timepiece. On the other hand, conventional watches, especially portable watches, are divided into a watch part and a belt part, as shown in FIG. In other words, the conventional concept of a watch required all electronic components to be mounted in the watch section. However, in the present invention, it is expected that a GPS receiver or the like will be equipped with quite a large number of components, and there is a possibility that the conventional watch section cannot be used alone. Therefore, in the present invention, an electronic component that realizes the functions of an LSI, an antenna, a solar cell, etc. required in the present invention is mounted on a conventional belt portion, that is, a part that is conventionally an accessory and has no relation to a watch. [Effects of the Invention] According to the present invention, a clock that could only measure 1 o'clock in the past can not only accurately measure and display its position by using GPSmffi radio waves, but can also measure and display its position accurately. Since it is possible to measure the difference from GPS standard time, if this time difference is automatically corrected, extremely accurate time can be displayed at all times.

[Brief explanation of the drawing]

FIG. 1 is a hardware configuration diagram of a watch according to an embodiment of the present invention, FIG. 2 is a block diagram of a GPS radio receiver, FIG. 3 is a processing flow diagram of the processing device 2 (positioning calculation), and FIG. A processing flow diagram of the processing device 7 (clock function), FIG. 5 is a hardware configuration diagram of the processing device 7, and FIG. 6 is a content diagram of the accumulator 23. FIG. 7 is a display example, FIG. 8 is an explanatory diagram showing an example of a memory map, FIG. 9 is a control flow diagram, and FIG. 10 is a display example. fz-th
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Claims (1)

[Claims] 1. A clock circuit for a watch, means for receiving radio waves from a global positioning system (GPS) satellite, a processing device capable of calculating a self-position from the GPS satellite, a clock and the above-mentioned GPS receiver. A timepiece characterized by having a control circuit that controls a processing device. 2. GPS required for receiving GPS signals in the above watch
2. The timepiece according to claim 1, comprising means for storing various data such as satellite orbit data and a priori position data of reception positions necessary for positioning calculations on a non-volatile and rewritable memory. 3. In the above watch, from the external input terminal attached to the watch, you can select the normal watch mode, the positioning mode using GPS radio waves, or rewrite the memory contents.
Items 1 and 2 have the function of specifying the time rewriting mode and have a control device to realize the specified function.
The clock mentioned in the section. 4. GPS used for GPS navigation calculations in the above watch
Conventional GD is used to simplify the process of satellite selection.
OP (Geometric Dilution of Pre
4 to choose instead of the norm called ciseon)
4. The timepiece according to any one of items 1 to 3, characterized in that a method of selecting a satellite is adopted using a criterion of maximizing the volume created by one satellite and a receiving position. 5. Inside the watch, there is an accumulator that updates the local time using the built-in clock, and a GPS
Standard time (Greenwich Mean Time accumulated from the beginning of the week)
It has two accumulators that are updated by a built-in clock, and a function that converts the contents of each accumulator, and a function that can correct the time by reflecting the bias error component of the time obtained by GPS positioning calculation to the contents of the two accumulators. The watch according to item 1, characterized in that it has: 6. In the above-mentioned watch, in order to make it possible to mount electronic components, LSI and I necessary for the watch function are installed, especially in the part conventionally called the band or belt in portable watches.
6. The watch according to items 1 to 5, characterized in that the watch is equipped with a battery, an antenna, a battery, and the like.