JP2000193483A - Portable gps receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a correct moving speed by removing the effect of a detection difference in arm swinging speed signal, a deviation between start timing and GPS positioning operation, a remarkable disturbance in periodic cycles of the arm swinging speed signal due to unsteady motion of a carrying user and others. SOLUTION: This portable GPS receiver is constituted of a microcomputer 1, a GPS receiving part 2 for measuring the moving speed of a carrying user, an input part 3 to set condition of various computations and control containing positioning interval data of the GPS part 2, an arm swinging detection part 4, a start timing setting part to set the start timing for the positioning computation at the GPS receiving part 2 based on the arm swinging speed signal and a display part 6 to display the moving speed or the like. The microcomputer 1 is provided with a speed averaging means to average the instantaneous moving speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable GPS receiver used in the field of leisure and sports, and more particularly to a portable GPS receiver for measuring the speed of a moving object.

[0002]

2. Description of the Related Art The GPS system, which is a satellite navigation system capable of continuously and independently performing three-dimensional positioning in any region on the earth, and simultaneously determining the speed, traveling direction, and accurate time of a moving object, has been developed. It has been used in car navigation systems that have been rapidly spreading in recent years and have become familiar. Also, in the field of leisure and sports, the use as a simple portable positioning device is gradually expanding by miniaturizing the GPS receiving device.

[0003] As a conventional portable GPS receiver, there is one disclosed in, for example, JP-A-4-351981. This portable GPS receiving device has a GPS receiving function, calculates the current latitude, longitude and altitude position information, the current time, further calculates the azimuth and distance, and displays it on the display device. In addition, power is supplied from a solar cell provided on a cover of the receiving device main body.

Japanese Patent Laid-Open Publication No. Hei 6-118156 discloses a receiving unit for receiving a GPS signal from a GPS satellite,
A position information calculation unit for obtaining position information for each predetermined time during the movement of the moving object from the GPS signal, a storage unit for storing the position information for each predetermined time, and a position for each predetermined time stored in the storage unit A palm-sized portable GPS receiver comprising a movement state calculation unit for calculating a movement distance and a total movement distance for each predetermined time based on the information, and a display unit for displaying a movement state as the calculated result information. It has been disclosed.

Japanese Patent Application Laid-Open No. 9-145814 discloses that a liquid crystal display and various operation keys are mounted on an outer surface of a card type case, and a map storage card (ROM) is inserted into and removed from the card type case. A patch type antenna for receiving a GPS signal from a GPS satellite, and a GPS for processing the received GPS signal to obtain positioning data of a mobile object are provided inside the card type case.
A receiving unit, an arithmetic processing unit that calculates the current position of the moving object based on the obtained positioning data, and the liquid crystal by superimposing the calculated current position of the moving object on a map read from the map storage card. There is disclosed a card-sized portable GPS receiving device including a display control unit for displaying on a display screen, that is, a device that can also be used as a receiving device for a portable car navigation system.

In general, various devices used in the leisure and sports fields are required to have excellent portability and operability. All of the above-mentioned conventional apparatuses satisfy these requirements for the time being, but cannot be said to be sufficient. Therefore, a portable GPS receiver particularly excellent in portability has been desired. Since it is a portable device, it is disclosed in Japanese Patent Laid-Open No. 9-145.
A receiving device for a portable car navigation system having a map storage card as disclosed in Japanese Patent No. 814,
This is not feasible due to the size of the map storage card. Therefore, the portable GPS receiving device basically functions as a receiving device that displays time, speed, distance, and the like on a liquid crystal display unit by numerals.

There are two methods for obtaining the moving distance and moving speed from point A to point B using the positioning data from the GPS receiver. First, the latitude and longitude of each of the point A and the point B are measured, the distance between them is calculated as a moving distance, and the moving distance is divided by a known moving time to obtain a moving speed. However, this method is basically applicable only when moving linearly. When performing a non-linear movement, refer to
As disclosed in Japanese Patent No. 8156, the measurement is performed by dividing into several linear portions. Moreover, currently available GPS services use only a C / A code called SPS and a navigation message to perform positioning. Since the measurement width of the absolute position is a radius of 10 m to 100 m, the measurement accuracy is not very high. Therefore, a method for measuring the speed of a moving object using the Doppler frequency of a carrier wave of a GPS radio wave has been proposed.
In fact it has been adopted. The latter method of measuring the speed of a moving object can be applied to a winding road or a track around a track, since the instantaneous moving speed at the time of measurement can be measured.

By the way, a human walks or runs while swinging his arm back and forth in the direction of travel. When moving at a constant speed, the speed of swinging up and down the arm is zero at the time of switching from swinging up to swinging down, the maximum when the arm passes the lowest point, the size gradually changes during this time,
When the horizontal axis is the time axis, a substantially sine wave is drawn as shown in FIG. On the other hand, the speed of the body in the traveling direction does not change periodically, but is substantially constant with respect to the time axis as shown in FIG. Since the portable GPS receiver is worn on the wrist, the ground speed is obtained by synthesizing the moving speed of the body and the speed of swinging the arm up and down. Therefore, the speed measured by the portable GPS receiver is a synthetic speed, not a moving speed of a person, that is, a carrier. Also, the GPS system includes SA (Se
An error referred to as “lective Availability” is given with a long fluctuation period of about 5 to 20 minutes. The ground speed measured by the portable GPS receiver in this case is as shown in FIG. For this reason, portable GP
In the S receiving device, the arm is swung up and down and SA
Therefore, there is a problem that a desired moving speed cannot be obtained. In addition to raising and lowering the arm and SA, periodic movement of the body during walking or running is an obstacle to obtaining a desired moving speed.

[0009] In a portable GPS receiver,
Due to the size limitation of the whole device, a small battery is inevitably used as a power source. By the way, the GPS receiver consumes considerably large power during operation. This imposes a very heavy burden on small batteries.

Accordingly, the present applicant has filed a patent application for a GPS receiver which has solved the above-mentioned problems (Japanese Patent Application No. 9-22636).
6). The invention according to the present application is a portable GPS receiver that employs a method of measuring the speed of a moving object using the Doppler frequency of a carrier wave of a GPS radio wave. The portable GPS receiving device includes a GPS receiving unit, a microcomputer, an input unit, a display unit, an arm swing detecting unit, and a start timing setting unit. Its features are that the power consumption is reduced by intermittently operating the positioning calculation operation of the GPS receiving unit at specific positioning intervals, and one of the periodic arm swing speed signals output by the arm swing detection unit. The effect of the arm swing is reduced by starting the positioning calculation in the GPS receiver at a specific timing of the cycle.

The above specific timing is, for example, the time point d or h in FIG. At these times, the relative speed of the arm to the body is zero. Therefore, if the GPS receiver is operated to perform the positioning calculation operation with these points in time as the specific timing, the effect of the arm swing can be theoretically completely removed. However, the detection error of the arm swing speed signal, the deviation between the specific timing and the GPS positioning calculation operation, the periodicity of the arm swing speed signal due to the unsteady body movement of the wearer, and the period due to SA Actually, there is still a problem that when a target error or the like occurs, the moving speed of the carrier cannot be obtained properly.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problem with the GPS reception based on a specific positioning start timing in one cycle of a body movement speed signal obtained by detecting a body movement of a carrier. In a portable GPS receiving apparatus in which the positioning calculation of the section is started and the positioning calculation operation is performed intermittently according to the positioning interval, the detection error of the arm swing speed signal, the time between the specific timing and the GPS positioning calculation operation Displacement, and even if the periodicity of the arm swing speed signal is significantly disturbed due to the unsteady body movement of the carrier or a periodic error due to SA, etc., an accurate moving speed of the carrier is obtained, and Is to be displayed.

[0013]

In order to solve the above-mentioned problems, a GPS receiver for receiving radio waves from GPS satellites and outputting positioning data including a Doppler frequency signal of a carrier wave;
A microcomputer that performs various calculations and controls in accordance with a program, a body movement detection unit that detects body movements of the carrier, and a GP based on a body movement speed signal output by the body movement detection unit.
A start timing setting unit that sets a positioning calculation start timing of the S receiving unit, an input unit that sets various calculation and control conditions including a positioning interval in the microcomputer, and a moving speed and a moving distance calculated by the microcomputer A portable GPS receiver is constituted by a display unit for displaying the information and the like. The microcomputer controls the GPS receiver to start positioning calculation based on the positioning calculation start timing and intermittently performs positioning calculation operation in accordance with the positioning interval. Means for calculating for each interval and speed averaging means for averaging the moving speed are provided. Further, the above-mentioned portable GPS receiving device is configured by using an arm swing detecting unit as the body motion detecting unit.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a portable GPS receiving apparatus according to the present invention is a microcomputer 1 for performing various calculations and controls in accordance with a program, receiving a radio wave from a GPS satellite and including a Doppler frequency signal of a carrier wave. A GPS receiving unit 2 for outputting data, an input unit 3 for setting various parameters including a positioning interval of a positioning calculation operation of the GPS receiving unit 2 to the microcomputer 1, an arm swing detecting unit 4 as a body motion detector of a wearer A start timing setting unit 5 for detecting a specific timing of one cycle of an output speed signal of the arm swing detection unit 4 and setting the same in the microcomputer 1 and a display unit for displaying a moving speed and a moving distance calculated by the microcomputer 1 5 is comprised.

The microcomputer 1 performs various arithmetic processing according to a control program and controls each component, and a read only memory (ROM) 1 storing a control program.
2. A random access memory (R) for storing various data and the like generated during execution of the control program by the CPU 11
AM) 13 and a clock generation unit 14 for generating an operation clock signal of the CPU 11. RAM
13, a positioning data storage unit 13a, a moving speed storage unit 1
3b, a moving distance storage unit 13c, a moving time storage unit 13d,
Start timing storage unit 13e and parameter etc. storage unit 1
3f is included.

The GPS receiver 2 comprises a receiving antenna 21 and a receiving circuit. The receiving circuit includes a band-amplifying circuit that amplifies the GPS radio wave received by the antenna, a down-converter circuit that converts an output frequency signal of the band-amplifying circuit into a predetermined intermediate frequency signal, and converts an analog signal output from the down-converter circuit into a digital signal. Analog to convert
It includes a digital conversion circuit and a message decoding circuit. By the way, in the currently available GPS system,
The radio wave transmitted from the GPS satellite is PSK-modulated with a pseudo-noise code (C / A code for identifying the satellite and navigation data such as satellite orbit information and time information), and is a 1.57542 GHz frequency signal spread spectrum. It is. Therefore, the message decoding circuit despreads the C / A code into the output signal of the analog / digital conversion circuit and outputs digital navigation data. The output of this message decryption circuit,
That is, the digital navigation data output from the GPS receiving unit 1 is temporarily stored in the positioning data storage unit 13a of the RAM 13 of the microcomputer 1. From the message decoding circuit, of course, speed data based on the Doppler frequency is also output.
3 is temporarily stored in the positioning data storage unit 13a.

The input unit 3 can set a start input and a stop input of the portable GPS receiver, and can also set parameters of a fixed distance, a fixed time, a golf distance, and a lap distance. . The input unit 3 also switches the mode from a fixed distance unit to a fixed time unit. These settings or switching are performed by operating the push button switch 31. The display unit 6 is controlled by the CPU 11 of the microcomputer 1 and displays a moving speed, a moving distance, a moving time and the like of the wearer on the liquid crystal panel 61 thereof.

The arm swing detecting section 4 comprises, for example, an acceleration sensor having a cantilever structure to which a piezoelectric element is attached, an amplifier circuit, and an analog / digital conversion circuit. Vibration according to the arm swing is sensed as mechanical displacement of the cantilever. This mechanical displacement is converted into a minute voltage analog signal by the piezoelectric element, amplified and input to the start timing setting unit 5.

The start timing setting unit 5 determines a d at a specific point in one cycle of the sine wave speed signal shown in FIG. 3, for example, a cross point d at which a straight line indicating the average body movement speed and a curve indicating the arm swing speed intersect. And a signal specifying the time point of time h, is converted into a digital signal, and is set in the microcomputer 1 as a positioning start timing signal. The microcomputer 1 temporarily stores the positioning start timing signal in the start timing storage unit 13e of the RAM 13. The start timing setting unit 5 includes, for example, a circuit component such as a voltage comparator and a reference voltage source that provides a reference value to one input terminal of the voltage comparator. The arm swing signal, i.e., the sine wave velocity signal, is applied to the other input terminal of the voltage comparator and generates an output signal when it matches the reference value. Therefore, the positioning start timing is changed by changing the reference value, and a, b, c, e, f, or g other than the above cross point can be set as the positioning start timing as needed.

The operation of the present invention will be described below with reference to FIG. The user operates the button switch 31 to operate the portable GP.
The S receiving device is started (101). Then CPU
11 determines whether a start input has been detected (1).
02). When the start input is detected, the CPU 11 performs an initial measurement process including initialization of the time measurement data and the moving distance data (103). When the initial measurement process is completed, the CPU
11 judges whether there is a positioning start timing signal of the GPS receiver 2 (104).

When detecting the positioning start timing signal, the CPU 11 controls the GPS receiver 2 to start the positioning calculation operation (105). The GPS receiver 2 measures the Doppler frequency of the carrier frequency and outputs a three-dimensional velocity vector signal of the carrier to the microcomputer 1 (106).
The CPU 11 corrects the elevation angle of the three-dimensional speed vector signal and further calculates and calculates the speed in the traveling direction of the wearer. This speed data, that is, the instantaneous moving speed data at the time of positioning is stored in the RAM 1.
No. 3 is stored in the positioning data storage unit 13a (106). Here, in the present embodiment, the moving speed is obtained from the Doppler frequency of the carrier wave. However, the CPU 11 may obtain the speed from the position data between two points using the side data output from the GPS receiving unit 2. it can. When the speed measurement processing (106) based on the Doppler frequency is completed, the CPU 1
1 controls the GPS receiver 2 to interrupt the positioning calculation operation (107).

Next, the CPU 11 reads the latest continuous plural, for example, four, instantaneous moving speed data from the positioning data storage unit 13a of the RAM 13, performs a moving average calculation to obtain an average moving speed of the carrier, and obtains the average. The moving speed data is stored in the moving speed storage unit 13b (108). Due to the average moving speed calculation processing, the detection error of the arm swing speed signal, the deviation between the specific timing and the GPS positioning calculation operation, and the periodicity of the arm swing speed signal due to the unsteady body movement of the wearer are remarkable. Since the influence of disturbance or the like is removed, the stored average moving speed becomes an accurate value. Further, if the average time is set to 5 minutes to 20 minutes or more, which is the period of the error due to SA, the influence of SA can be reduced.

In the present invention, the instantaneous moving speed of the carrier is detected as a three-dimensional speed component of an E component (east-west component), an N component (south-north component) and an altitude component by measuring the Doppler frequency of the GPS radio wave. You. Therefore, the microcomputer 1 is provided with speed averaging means for individually averaging the E component and the N component, synthesizing the respective average speed components, and obtaining the average moving speed of the carrier. Is also good. The microcomputer 1 further comprises a speed averaging means for dividing the speed component in the traveling direction and the speed component in the orthogonal direction, individually averaging them, synthesizing the respective average speed components, and obtaining the average moving speed of the wearer. May be prepared.

Subsequent to the average moving speed calculation processing (108), the CPU 11 calculates the cumulative moving distance from the start to the present, and stores the accumulated moving distance data in the moving distance storage unit 1.
3c (109). The cumulative moving distance is obtained by calculating the product of the positioning interval and the average moving speed for each positioning calculation, that is, the moving distance for each positioning interval, and accumulating the distance from the start to the present. Next, the CPU 11 reads the average traveling speed data from the traveling speed storage unit 13b and the accumulated traveling distance data from the traveling distance storage unit 13c of the RAM 13, respectively.
The display unit 4 is controlled to display the average moving speed and the cumulative moving distance of the wearer (110).

Subsequently, the CPU 11 determines whether there is a stop input (111). When the stop input is detected, the CPU 11 performs a stop process and accumulates a stop output in the moving distance storage unit 13c or the moving time storage unit 13d of the RAM 13 (116). After that, the CPU 11
The stop output is read from the AM 13, the display unit 4 is controlled to display the stop output (117), and the measurement of the speed and the distance is ended (118). When a stop is performed when the fixed distance is reached, the stop input is distance and the stop output is time, that is, the time when the fixed distance is reached.
Therefore, in the case of a game in which the time at a certain distance is fought, the stop output is the goal time. When a stop is performed when a certain time is reached, the stop input is time, and the stop output is a distance, that is, a distance moved in a certain time. Therefore, in the case of a competition in which a distance is competed for a certain time, the stop output is the goal distance or the total distance. The stop input is set in the microcomputer 1 before the wearer operates the input unit 3 to measure the speed and the distance. Of course, there is also a stop input which is forcibly input by the carrier on the way.

When the stop input is not detected,
The CPU 11 determines whether there is a lap input (11).
2). When the lap input is detected, the CPU 11 performs the lap processing and stores the lap output in the moving distance storage unit 13c or the moving time storage unit 13d of the RAM 13 (11).
3). Thereafter, the CPU 11 reads the lap output from the RAM 13 and controls the display unit 4 to display the lap output (114). When lapping is performed when a certain distance is reached, the lap input is distance and the lap output is time,
It is time to reach a certain distance. When lapping is performed when the predetermined time is reached, the lap input is time, and the lap output is the distance, that is, the distance moved during the predetermined time. The lap input is set in the microcomputer 1 before the wearer operates the input unit 3 to measure the speed and the distance.
Of course, there is also a lap input forcibly input by the wearer on the way.

If no lap input is detected, C
The PU 11 determines whether a predetermined positioning interval has elapsed from the immediately preceding positioning start time (115). If the predetermined positioning interval has elapsed, the CPU 11 determines whether there is a positioning start timing signal of the GPS receiving unit 2 (104).
Hereinafter, a series of operations according to the above flow is repeated until a stop input is detected.

In the present invention, speed averaging is performed at regular intervals or at regular distances. When averaging cannot be performed, for example, when averaging is set at intervals of 10 seconds, and when the time does not reach 10 seconds, raw data that has not been averaged is displayed, and the fact that the data is raw data is also displayed. I do. Since GPS radio waves cannot be received in places where radio waves do not reach, such as in a tunnel, in such a case, the immediately preceding average moving speed is displayed, and this is used as the speed for calculating the cumulative moving distance.

As described above, in the present invention, in order to reduce the power consumption of the device, the GPS receiving section 2 which consumes a large amount of power performs the positioning calculation operation intermittently at fixed positioning intervals. The positioning interval is set in the microcomputer 1 by operating the input unit 3, and its size is an appropriate value assumed from the moving speed of the wearer, that is, about several seconds. If the average moving speed does not fluctuate much,
By setting the positioning interval larger than the set value, the power consumption can be further reduced. This is the microcomputer 1
Means for monitoring fluctuations in the average speed, and means for changing the positioning interval data stored in the parameter storage unit 13e when the variation range of the average moving speed is within the set range for a certain period of time. it can.

[0030]

According to the present invention, in a portable GPS receiver for measuring the speed of a moving object, the instantaneous moving speed at each measurement time is averaged at predetermined intervals according to the purpose of use and displayed on a display unit. Therefore, the moving speed displayed on the display unit is the detection error of the arm swing speed signal, the deviation between the specific timing and the GPS positioning calculation operation, and the arm swing speed signal due to the unsteady body movement of the carrier. Even if remarkable disturbances in the periodicity of, or a periodic error due to SA, etc., occur, these effects become accurate values substantially eliminated. Also, GP
Since the positioning calculation operation of the S receiving unit is controlled so as to be performed intermittently at a predetermined positioning interval, the power consumption of the device is reduced, and it is possible to use the device for a long time even with a small battery as a power source.

Further, the portable GPS receiving apparatus according to the present invention is not limited to the case where the portable GPS receiving apparatus is used by being worn on a pedestrian or a runner or the like, but is mounted on a moving object such as a bicycle or a car or a sporting animal such as a horse. In such a case, an accurate moving speed can be displayed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of a portable GPS receiver.

FIG. 2 is a flowchart illustrating an example of an operation of the portable GPS receiving device.

FIG. 3 is a diagram for explaining how the effect of arm swing appears when the portable GPS receiver is used while worn on an arm.

FIG. 4 is a diagram for explaining how the effect of arm swing and the effect of SA appear when the portable GPS receiver is used while worn on the arm.

FIG. 5 is a perspective view of one embodiment of a portable GPS receiving device when worn on an arm.

[Description of Signs] 1 microcomputer 2 GPS receiving unit 3 input unit 4 arm swing detecting unit 5 start timing setting unit 6 display unit 11 CPU 12 ROM 13 RAM 13a positioning data storage unit 13b moving speed storage unit 13c moving distance storage unit 13d Moving time storage unit 13e Start timing storage unit 13f Parameter storage unit 21 Receiving antenna 31 Push button switch 61 Liquid crystal panel

Claims (2)

[Claims] 1. A GP for receiving a radio wave from a GPS satellite and outputting positioning data including a Doppler frequency signal of a carrier wave.
An S receiving unit, a microcomputer that performs various calculations and controls according to a program, a body movement detecting unit that detects body movements of a carrier, and a positioning of the GPS receiving unit based on a body movement speed signal output by the body movement detecting unit. A start timing setting unit for setting a start timing of the calculation, an input unit for setting various calculation and control conditions including a positioning interval in the microcomputer, and a moving speed and a moving distance calculated by the microcomputer are displayed. Portable G consisting of display unit
A PS receiving apparatus, wherein the microcomputer is configured to start positioning calculation of the GPS receiving unit based on the positioning start timing and to perform positioning calculation operation intermittently according to the positioning interval; A portable GPS receiver comprising at least means for calculating a speed at predetermined intervals and speed averaging means for averaging the moving speed. 2. The portable GPS receiving device according to claim 1, wherein said body movement detecting unit is an arm swing detecting unit.