JP2002250764A - Gps position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a GPS position detector equipped with a new function by which the radio-wave receiving condition of the GPS position detector is estimated on the basis of the output of an environment sensor and by which an integration processing operation can be selected and executed with reference to the matrix search processing operation of a GPS signal while the integration period of the integration processing operation is being changed over automatically. SOLUTION: The GPS position detector is provided with a GPS antenna 1, the environment sensor 11 which senses an ambient environment condition for estimating the reception strength of GPS radio waves and a GPS positioning processing part B which contains matrix search processing circuits 4, 5 for capturing a GPS satellite. The function which executes a prescribed integration processing operation is added to the circuits 4, 5, the integration processing operation is executed selectively according to the reception strength of the GPS radio waves estimated on the basis of the output of the environment sensor 11, the GPS radio waves from the GPS satellite are captured, and a navigation message is decoded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of estimating GPS radio field intensity from the output of an environmental sensor, and changing the time of integration calculation performed in a matrix search process in accordance with the level of radio field intensity. GP with new functions that can be executed
The present invention relates to an S position detecting device.

[0002]

2. Description of the Related Art Weak high-frequency radio waves (hereinafter referred to as GPS radio waves) transmitted from a GPS satellite orbiting above the earth (hereinafter also referred to as "satellite") by pseudo-noise encoding, frequency-converted, and subjected to a predetermined period , Digitized and extracted as a GPS signal, and the extracted GPS
A GPS position detecting device that decodes a signal's arrival time on the ground and a navigation message included in the GPS signal to accurately determine the position information on the earth has been widely used with the recent development of communication technology. It has become.

[0003] Such a GPS position detecting device captures at least four or more (three or more in the case of two-dimensional positioning) GPS satellites orbiting the visible space, and acquires the respective GP satellites.
It is necessary to frequency-convert and decode the GPS signal transmitted from the S satellite after being pseudo-noise-coded in the form of high-frequency radio waves, and the decoding requires the frequency-converted GPS signal and the orbiting satellite to be captured. Of the GPS signal of the GPS satellite is synchronized with a code signal (C / A code) assigned in advance, and a navigation message carried on the GPS signal transmitted from the orbiting satellite to be acquired is extracted (hereinafter, referred to as a GPS message). It is necessary to decode the extracted navigation message and perform predetermined arithmetic processing.

[0004] However, GPS radio waves transmitted from GPS satellites are attenuated by the influence of the surrounding environment. For example, in an urban area where tall buildings are densely located, and in a countryside or a countryside where there are few buildings, the GPS radio wave is received by a GPS antenna. In a city area where there are many radio obstacles, the radio field intensity is attenuated and contains a lot of noise, so that the navigation message extracted from the pseudo-noise-encoded GPS signal becomes an undecipherable error, At present, it takes time to adjust signal timing.

Therefore, when performing such a matrix search process, the frequency-converted GPS signal and the GP
A predetermined integration process is executed for a predetermined time while adjusting the timing of the C / A code according to the S satellite, and it is determined whether or not the integrated value at that time exceeds a predetermined threshold value. Then, it is determined whether the timing is matched or not. According to the matrix search processing with such integration processing, the frequency-converted GP
When the timing of the S signal matches the timing of the C / A code of the 1023 chip, the integrated value increases,
If the timing adjustment does not match, the integrated value is prevented from increasing, so that the timing adjustment can be determined based on the integrated value.

[0006] That is, if such integration processing is added simultaneously with the matrix search processing under the assumption that the GPS radio wave is weak, the integrated value calculated by the integration processing will be a predetermined threshold value. If it exceeds, it can be determined that the timing adjustment at that time has coincided. Thereafter, the C / A code of the 1023 chip is locked and G
An exclusive OR of the PS signal and the locked C / A code of the 1023 chip is sequentially output to extract the navigation message.

In such a matrix search process,
The longer the integration period for performing the integration operation, the more
The noise included in the weak signal can be removed, and the timing can be reliably adjusted even for a weak signal.

[0008]

However, in an apparatus provided with a matrix search processing circuit for executing an addition operation by adding an integration operation, for example, the frequency interval is 500 Hz when the integration period is 1 msec and 50 H when the integration period is 10 msec.
When the integration period is lengthened so that the frequency is 5 Hz at 100 msec, the processing time of the integration process increases exponentially, and a weak signal including noise can be reliably processed. If the reception intensity is high, there is a problem that useless time is required.

The present invention has been developed in view of such circumstances, and has as its object to provide means for estimating and discriminating the GPS radio field intensity based on the output value of an environment sensor, and to provide a GPS signal transmitted from an orbiting satellite. A new function is provided to control the matrix search process executed to capture signals while automatically switching the integration period of the integration calculation process, and to quickly execute GPS positioning according to the strength of radio wave intensity. GP
An object of the present invention is to provide an S position detecting device.

[0010]

According to a first aspect of the present invention, there is provided a GPS position detecting apparatus for detecting a GPS antenna and surrounding environmental conditions for estimating the reception intensity of a GPS radio wave. It has an environment sensor and a GPS positioning calculation processing section including a matrix search processing circuit for capturing GPS satellites, and has the following features.

That is, in this GPS position detecting device,
The matrix search processing circuit is provided with a function of executing a predetermined integration calculation process, and the G estimated by the output of the environment sensor is added.
According to the reception strength of the PS radio wave, the above-described integration calculation process is selectively executed to capture the GPS radio wave from the GPS satellite and decode the navigation message.

Here, the predetermined integration operation processing includes an operation processing using a GPS signal and a code signal for pseudo noise encoding, which is executed together with the matrix search processing. The processing circuit is configured so that the integration period for executing the calculation can be appropriately changed according to the radio wave intensity. For example, a circuit that includes two circuits, one that performs integration processing with a short integration period and one that performs long processing, or a circuit that performs integration processing with a short integration period and a circuit that performs long processing, and a circuit that performs a long integration. And the like including three circuits for executing the integration processing of the above.

According to a second aspect of the present invention, in the first aspect, the matrix search processing circuit is separated into two or more matrix search processing circuits that execute integration calculation processes having different lengths of integration periods. Either of the matrix search processing circuits outputs the G estimated by the output of the environment sensor.
The operation is selectively performed according to the reception intensity of the PS radio wave.

According to a third aspect, in the first or second aspect,
In the multiplication operation in the matrix search processing circuit, the exclusive OR of a GPS signal, which is frequency-converted from a GPS radio wave and is digitally coded, and a code signal used for pseudo-noise coding of the GPS signal are sequentially bit-coded. For each shift, G estimated by the output of the environment sensor
The operation of outputting the exclusive-OR output of the GPS signal output during the integration period set according to the reception intensity of the PS radio wave and the code signal during that period is repeated, and as a result, the integrated value becomes a predetermined value. When the threshold value is exceeded, a code signal for the GPS signal is locked, an exclusive OR with the GPS signal is sequentially output, and processing for extracting the navigation message is executed.

In the matrix search processing circuit, a GPS signal and
A predetermined integration operation is performed for a predetermined time on the exclusive OR output obtained by performing timing adjustment with the code signal for a predetermined time.
The code signal is sequentially shifted by bits. In each integration operation, the bit match is determined based on the exclusive OR output of the GPS signal and the code signal, and the matched bits are integrated. When the integrated value obtained as above exceeds a predetermined threshold value, it is considered that the timing alignment between the GPS signal and the code signal matches, and the bit shift of the code signal with respect to the GPS signal is locked, and the arithmetic processing is performed. Is stopped, and thereafter, processing for extracting the navigation message is performed.

For example, whether the signal processing unit gives a predetermined time to the matrix search processing circuit as an integration period parameter,
Alternatively, if the configuration is such that the program is selectively switched, there is no need to have a plurality of circuits having different integration periods, and the hardware configuration can be simplified.

According to a fourth aspect, in the second or third aspect,
An illuminance sensor is used as an environment sensor, and the GPS position detecting device is configured to output a current time measured by a clock unit provided therein and an output from the illuminance sensor when the illuminance exceeds a predetermined illuminance level in the daytime. In the meantime, while performing the matrix search processing by executing the integration calculation processing with a short integration period, if the illumination level is lower than a predetermined illuminance level in the daytime, the integration processing with the long integration period is performed to perform the matrix search processing. G
It is characterized in that the timing of the PS signal and the code signal is adjusted.

According to claim 5, in claim 2 or 3,
The environment sensor includes an image sensor, and the GPS position detection device further includes an image processing circuit that analyzes a spatial frequency distribution from a surrounding image captured by the image sensor. In the case where many low frequency components are included, an integration operation process with a short integration period is executed to perform a matrix search process, while in the case where the surrounding image includes many high frequency components, The present invention is characterized in that a matrix search process is performed by executing an integration operation process having a long integration period, and the timing of a GPS signal and a code signal is adjusted.

According to a sixth aspect of the present invention, the GPS position detecting device is provided with a use mode selection setting switch for selecting outdoor or indoor, and any one of the above modes is set according to the mode set by the use mode selection setting switch. It is characterized in that the matrix search processing is selectively executed and the timing of the GPS signal and the code signal is adjusted.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of a main configuration of a GPS position detecting device according to the present invention.

The GPS position detecting device A is a high frequency processing unit 2 for converting a GPS radio wave (RF signal) received by the GPS antenna 1 into an intermediate frequency signal IF. A signal processing unit 3 that determines which of the matrix search processing circuits 4 and 5 having different lengths to select and performs switching control, a GPS positioning calculation processing unit B that performs data processing and calculations required for GPS positioning,
A lightness analyzing unit 10 is provided for analyzing lightness from an output value of an illuminance sensor 11 constituting an environment sensor used for estimating GPS radio wave intensity. Note that a communication processing unit for performing two-way communication with a network such as a mobile phone network may be provided.

The GPS positioning operation processing section B is composed of a CPU and its peripheral circuits. Functionally, the GPS positioning operation processing section B receives a pseudo-noise-encoded GPS signal received by the GPS antenna 1.
GPS signal from a specific orbiting satellite to capture GPS signals from the orbiting satellite and extract navigation messages from the signals, and decode the navigation messages extracted by the GPS satellite acquisition and tracking processing unit C to measure the pseudorange The navigation message decoding / arithmetic processing unit D performs predetermined arithmetic processing to calculate latitude and longitude information.

In the GPS satellite acquisition processing circuit B, pseudo-noise-encoded GPS signals transmitted from four or more orbiting satellites required for GPS positioning (three or more in the case of two-dimensional positioning) are transmitted.
In order to capture the signal, a matrix search process is performed by adjusting the timing of the frequency-converted, sampled, digitally processed GPS signal and the C / A code assigned to each orbiting satellite. Are locked, and the navigation messages are sequentially extracted from the GPS signal.

In such a matrix search process, taking into account the Doppler effect and the error of the oscillator, the frequency is shifted by a predetermined value (for example, 500 Hz) to extract the pseudo noise code of the satellite to be tracked, The navigation message (H, L or 1,0 code signal) is extracted by synchronizing the coding pattern of the C / A code assigned to the satellite with the noise code.

From all the orbiting satellites, a GPS radio wave phase-modulated by pseudo noise coding with a C / A code of 1023 chips assigned to each satellite is transmitted at the same frequency. The GPS radio wave received at 1 is detected and amplified, and then extracted as an intermediate frequency signal. The extracted intermediate frequency signal is further sampled and quantized at a predetermined cycle,
It is extracted as a digitized GPS signal.

Such a pseudo-encoded GPS signal is transmitted with a period of 1 msec, and the navigation message is transmitted with 20 times 20 msec as one bit.

The basic concept of the matrix search process is as follows.
If the C / A code of the 023 chip and the GPS signal are out of alignment, the navigation message cannot be decoded, and therefore the C / A code of the 1023 chip and the GP
Until the timing with the S signal is completely matched, the timing adjustment of the C / A code according to the satellite to be acquired is 1
This is performed by sequentially shifting the bits in units of 1 bit of the H.023 chip.
Lock the bit shift of the 1023-bit C / A code generated from the C / A code generation circuit provided inside the PS position detection device, and decode various information necessary for GPS positioning from the navigation message. Becomes

FIGS. 7A to 7C show the basic operation of the pseudo-noise encoding of the navigation message and the decoding thereof.

On the GPS satellite side, as shown in (a), the navigation message is pseudo-noise coded using the C / A code, is generated as a GPS signal, and the generated G is generated.
The PS signal is further phase-modulated and has a weak G with a high frequency.
It is emitted as PS radio waves.

On the other hand, on the GPS terminal side, the GPS
After receiving the GPS radio wave with the antenna, the digitized GPS signal is subjected to matrix search processing while bit-shifting the C / A code in order to match the timing with the C / A code. And C /
It is output as an exclusive OR with the A code.

In this case, the exclusive OR output is obtained if the timings of the GPS signal and the C / A code match.
A navigation message that is a long 1-bit signal as shown in (b) is extracted, but if the timing of the GPS signal and the C / A code do not match, a comb as shown in (c) is used. The toothed output is retrieved and the navigation message fails.

In the present invention, the matrix search processing circuits 4, 5
However, since the integration calculation process described in detail later is executed for each bit shift, if the integration value integrated by the calculation process exceeds a predetermined threshold value, it can be considered that the timing is matched. Therefore, even if the signal includes noise, the timing can be adjusted with the GPS signal. Here, the matrix search processing circuit 4 executes an integration operation with a long integration period, and the matrix search processing circuit 5 executes an integration operation with a short integration period.

In the GPS positioning, a matrix search process for the four GPS satellites to be captured is executed sequentially or in parallel in such a manner, and the navigation messages extracted from the respective GPS satellites are decoded. G
As a result of the predetermined calculation processing performed by the PS positioning calculation processing section B, the latitude and longitude of the GPS position detection device on the earth are accurately calculated.

In the embodiment shown in FIG. 1, the GPS satellite acquisition and tracking processing C includes a matrix search processing circuit 4 having a long integration period for processing a weak GPS signal and a signal for processing a signal of normal strength. Matrix search processing circuit 5 with short integration period
The signal processing unit 3 switches and selects the matrix search processing circuits 4 and 5 according to the analysis result of the brightness by the input from the illuminance sensor 11 as described later. The processing is executed.

That is, when the signal processing section 3 exceeds the predetermined illuminance level in the daytime, the signal processing section 3 activates the matrix search processing circuit 5 having a short integration period, while decreasing the predetermined illuminance level in the daytime. In this case, the timing of the GPS signal and the code signal is adjusted by operating the matrix search processing circuit 4 having a long integration period (claims 2 and 4).

The navigation message decoding / operation processing unit D
Is a measuring unit 6 for calculating the distance between the terminal and the orbiting satellite in a pseudo manner from the difference between the time on the GPS signal transmitted from the captured orbiting satellite and the reception time of the terminal on the ground.
And G captured by the GPS satellite capture and tracking processing unit C.
A data decoding unit 7 for decoding the navigation message extracted from the PS signal, and a positioning calculation unit 8 for calculating the latitude and longitude positions of the GPS position detecting device based on the pseudorange and the navigation message are provided. Have.

The measuring unit 6 calculates the pseudo distance between the captured satellite and the receiving location, and the data decoding unit 7 extracts GPS time, clock correction value, and satellite orbit information (ephemeris) from the navigation message. Then, the coordinate position of the satellite is calculated. Then, the positioning calculation unit 8 calculates the latitude and longitude of the receiving place on the earth from the pseudo distance calculated by the measurement unit 6 and the coordinate positions of at least four or more satellites calculated by the data decoding unit 7.

Note that the matrix search processing circuit of the present invention is not limited to such a circuit configuration, and one matrix search processing circuit may be used in common to perform an integration operation for an appropriate integration period in accordance with the output of the environmental sensor. A configuration that can selectively execute processing may be adopted (claim 3).

FIG. 2 is a block diagram showing an example of a main configuration of a GPS position detecting device using an image sensor as an environment sensor.

The apparatus A includes a GPS antenna 1, a high frequency processing unit 2, a signal processing unit 3, a GPS positioning operation processing unit B, a CCD camera 13 as an environment sensor, and an image processing unit for analyzing brightness. 12 are included.

The image processing unit 12 analyzes the image captured by the CCD camera 13 to perform a known arithmetic operation such as a discrete cosine transform to analyze a spatial frequency distribution included in the image. Analyze the degree of the components.

The signal processing unit 3 determines G
The reception strength of the PS radio wave is estimated, and the matrix search processing circuit 4 having a long integration period or the matrix search processing circuit 5 having a short integration period is switched.

That is, when the image analyzed by the image processing unit 12 has a monotonous scenery such as a mountain or a rural area, FIG.
As shown in FIG. 3A, many low spatial frequency components are included. However, in an urban area where buildings are densely lined, many high spatial frequency components are included as shown in FIG. 3B. , Identify these. If many low spatial frequency components are included, it is assumed that the reception intensity of the GPS radio wave is high, and the matrix search processing circuit 5 with a short integration period is selected to execute the processing. When many components are included, it is assumed that the reception intensity of the GPS radio wave is weak, and the matrix search processing circuit 4 having a long integration period is selected. At night, the CCD camera 13 may be replaced with a night vision camera.

The GPS position detecting device A described above estimates the reception intensity of the GPS radio wave based on the value output from the illuminance sensor 11 or the CCD camera 13, and further sets a use mode selection for selecting indoor or outdoor. A switch may be provided to selectively operate the matrix search processing circuits 4 and 5 by judging the strength of the reception intensity of the GPS radio wave according to the selected and set mode.

Next, an example of a matrix search process including an integration operation process performed in the present invention will be described.

When the reception strength of the GPS radio wave is weak, the frequency-converted GPS signal contains many noise components. Therefore, the frequency-converted GPS signal and the 1023-chip C signal corresponding to the GPS satellite to be captured are used.
Even if a matrix search process (without multiplication operation process) for extracting the navigation message by adjusting the timing of the / A code is executed, the navigation message becomes an error and cannot be decoded because the timing does not match.

Therefore, in the matrix search processing circuits 4 and 5,
When performing such a matrix search process, the frequency-converted GPS signal and the C / A corresponding to the GPS satellite to be captured are used.
A predetermined integration calculation process is performed for a predetermined period while the timing of the code is adjusted, and the integrated value at that time is determined, so that it is possible to determine whether the timing alignment matches or not. Therefore, in such a matrix search process, if the timing of the demodulated GPS signal matches the timing of the C / A code of the 1023 chip, the integrated value is increased. Employs an arithmetic processing that does not increase the integrated value.

In this embodiment, the matrix search processing circuit 4 has a long integration period and a short integration period 5. However, the matrix search processing circuit 4 may be composed of three or more circuits having different integration periods.

The setting of such an integration period is usually performed by GP
The initial setting of the S position detecting device is performed before shipment from the factory. However, in consideration of the use conditions, the user may be able to set a long matrix search process with a long integration period and a short matrix search process. Good.

FIG. 4 shows a matrix search process with a long integration period.
FIG. 5 shows the basic concept of the matrix search processing with a short integration period.

Here, (a) shows the basic principle of the integration operation processing. In order to take an exclusive OR with the GPS signal, the C3 of the 1023 chip repeatedly output with the bit shift fixed. The output period of the / A code is shown corresponding to the integration period, and (b) is obtained when the C / A code of 1023 chips is bit-shifted and the integration operation is performed in the matrix search process. FIG. 4 shows a spread spectrum diagram, in which the horizontal axis represents a search condition (timing adjustment) of a C / A code when a bit shift is performed and an integration operation is performed, and the vertical axis represents an integration calculation process. The integrated value is shown as detected energy. In these figures, the square value of the integrated value is shown as the detected energy in consideration of the sign.

The integration period of the matrix search processing circuit 5 shown in FIG. 5 is 1 msec, whereas the integration period of the matrix search processing circuit 4 shown in FIG. 4 is 20 msec.
Since the frequency step of the matrix search processing is also increased by a factor of 20, the time required for the matrix search processing circuit 4 is 400 times longer than that of the integration calculation processing.

In the integration calculation process, the timing can be adjusted even with a weak GPS radio wave. However, in the present invention, the radio wave intensity is estimated by measurement of an environment sensor in order to speed up the process. If the radio wave intensity is strong to some extent, the matrix search processing circuit 5 which does not require time is selected so that the timing can be adjusted in a short time.

Next, the integration calculation processing will be described in more detail.

Steps 101 to 107 in FIG. 6 are time charts showing the basic operation of the integration calculation process executed every time the C / A code is bit-shifted in such a matrix search process.

Upon receiving the command to start integration, the matrix search processing circuits 4 and 5 receive the digitized GPS signal and the 102 signals assigned to the GPS signals of the orbiting satellites to be captured.
An exclusive OR with a 3-chip C / A code is output.

That is, an exclusive OR is output between all the bit signals of the C / A code of 1023 chips and the corresponding bit signals of the digitized GPS signals after the frequency conversion by the high frequency unit 2. Then, all output values are integrated to calculate an integrated value.

Such an integration operation is repeatedly performed for a predetermined integration period with the bits of the C / A code fixed, and during such an integration period, the integrated value reaches a predetermined threshold value. If not, the C / A code is bit-shifted and the same multiplication operation is repeated.
When the integrated value exceeds a predetermined threshold value during any of the integration periods, the bit shift of the C / A code is stopped at that time, and thereafter, the C / A code and the GPS signal are kept fixed. An exclusive OR is output and extracted as a navigation message.

As shown in FIG. 7, the navigation message carried on the GPS signal has a bit rate sufficiently longer than that of the C / A code and is a signal of "H" and "L" or "1" and "0". , The exclusive-OR of the GPS signal and the C / A code is determined by the codes “H” and “L” corresponding to the code of the navigation message even when the timings of both signals coincide. Alternatively, it has “1” and “0”. Therefore, in the integration operation, it is necessary to identify the code, but in order to perform a threshold check without distinguishing the code, a value obtained by squaring the integration value is used as a true integration value. When the threshold value is exceeded, the exclusive-OR output indicates "H", "L" or "1", "0".
Are considered to have been retrieved.

Note that the GPS signal is pseudo-noise-coded using a 1023-bit C / A code (1 msec) whose bit length (about 20 msec) is extremely short compared to that of the navigation message. Such a multiplication operation is performed in a time width shorter than one bit length of the navigation message.

In the matrix search process, if the integrated value does not exceed a predetermined threshold value during the integration period in which the above-described integration calculation process is being performed, the GPS signal and the C / A
Assuming that the timing of the C / A code did not match the code, the C / A code is repeatedly subjected to the same integration calculation processing after the bit shift, while the integration value of the C / A code is a predetermined value in any integration period. When the threshold value is exceeded, it is considered that the timing of the GPS signal and the C / A code match, and the subsequent bit shift is stopped, the C / A code is locked, and the exclusive use of the GPS signal is performed. The OR output is sequentially output to extract the navigation message.

It should be noted that the integration operation is not limited to the method described above, and any method may be used as long as it can discriminate between coincidence and non-coincidence of timing alignment based on the calculated value.

[0064]

As can be understood from the above description, according to the present invention, the reception intensity of the GPS radio wave is estimated using the environment sensor. When it is inferred that it is weak, an integration operation with a long integration period is additionally executed in the matrix search process. Therefore, satellite capture can be performed reliably even with a weak radio wave including noise. On the other hand, when the reception intensity of the GPS radio wave is sufficiently high, the matrix search processing with the addition of the integration operation with a short integration period is executed, so that the positioning can be speeded up.

In particular, in the present invention, the matrix search processing circuit is separated into a matrix search processing circuit having a long integration period and a matrix search processing circuit having a short integration period. An appropriate circuit can be selected and executed according to the radio wave intensity. In claim 3,
Since the configuration is such that one matrix search processing circuit is shared and the program to be executed or the integration period parameter is selectively switched in the signal processing unit, the hardware configuration can be simplified.

According to the fourth aspect, since the environment sensor is constituted by an illuminance sensor, the illuminance at day or night is determined, and
It is possible to estimate the reception strength of the PS radio wave and execute any of the matrix search processes according to the reception strength.

Further, according to the fifth aspect, since the spatial frequency distribution is analyzed from the surrounding image picked up by the image sensor, the surrounding GPS radio field intensity is estimated based on the frequency component, and the same control is performed. Can be.

According to the sixth aspect, since the use mode selection setting switch for selecting the outdoor or the indoor is provided, the user can
By estimating the GPS radio field intensity according to the use conditions, it is possible to freely set which matrix search process to select.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a main configuration of a GPS position detection device using an illuminance sensor as an environment sensor.

FIG. 2 is a block diagram showing an example of a main configuration of a GPS position detecting device using an image sensor as an environment sensor.

3A is a diagram schematically illustrating an analysis result of a surrounding image including many low frequency components, and FIG. 3B is a diagram schematically illustrating an analysis result of a surrounding image including many high frequency components. FIG.

FIG. 4 is a diagram illustrating a basic principle of a matrix search process for executing an integration operation process with a long integration period.

FIG. 5 is a diagram showing a basic principle of a matrix search process for executing an integration operation process with a short integration period.

FIG. 6 is a flowchart illustrating a basic procedure of an integration operation performed in a matrix search process.

FIG. 7 is a diagram illustrating pseudo noise encoding processing of a GPS signal in a GPS satellite and pseudo noise encoded G in a GPS terminal.
FIG. 7 is an explanatory diagram of a basic principle showing a decoding process for extracting a navigation message from a PS signal.

[Explanation of symbols]

 Reference Signs List A GPS position detection device B GPS positioning calculation processing unit 1 GPS antenna 4 Matrix search processing circuit with long integration period 5 Matrix search processing circuit with short integration period 10 Lightness analysis unit 11 Illuminance sensor 12 Image processing unit 13 Image sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Suzuki 1048 Kazuma Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. Inventor Masahito Fukuda 1048 Kadoma Kadoma, Kadoma City, Osaka Pref. (72) Inventor Koji Sakamoto 1048 Kadoma Kadoma, Kadoma City, Osaka Pref. 1048 Matsushita Electric Works Co., Ltd. ) Inventor Kazuhiro Kawamoto 1048 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Works Co., Ltd. F-term (reference) 5 J062 AA01 CC07 DD05 DD12 DD22 DD23 EE01 EE03 FF00 FF02

Claims (6)

[Claims] 1. A GPS antenna, an environment sensor for detecting a surrounding environment condition for estimating a reception intensity of a GPS radio wave, and a GPS positioning operation processing unit including a matrix search processing circuit for capturing a GPS satellite. A GPS position detecting device comprising: a matrix search processing circuit having a function of executing a predetermined integration calculation process; wherein the integration is performed in accordance with a reception intensity of a GPS radio wave estimated from an output of the environment sensor. A GPS position detecting device for selectively executing arithmetic processing, capturing GPS radio waves from GPS satellites, and decoding navigation messages. 2. The matrix search processing circuit according to claim 1, wherein said matrix search processing circuit is separated into two or more matrix search processing circuits for executing integration calculation processes having different lengths of integration periods. Either one of the processing circuits outputs the GP estimated by the output of the environmental sensor.
A GPS position detection device, wherein the GPS position detection device is configured to be selectively operated according to the reception intensity of an S radio wave. 3. The multiplication operation in the matrix search processing circuit according to claim 1, wherein the multiplication operation in the matrix search processing circuit is performed by digitally encoding a GPS signal by frequency conversion from a GPS radio wave and a code signal used for pseudo-noise encoding of the GPS signal. Every time the code signal is sequentially bit-shifted, the exclusive OR is output over an integration period set in accordance with the reception intensity of the GPS radio wave estimated by the output of the environment sensor, and the GPS output during that time is output. The operation of integrating the exclusive-OR output of the signal and the code signal is repeated. As a result, when the integrated value exceeds a predetermined threshold value, the code signal for the GPS signal is locked, and A GPS position detecting device for performing a process of sequentially outputting exclusive ORs and extracting a navigation message. 4. The illuminance sensor according to claim 2, wherein the environment sensor comprises an illuminance sensor, and the GPS position detecting device includes a current time measured by clock means provided therein and the illuminance sensor. When the output exceeds the predetermined illuminance level in the daytime, an integration calculation process with a short integration period is performed to perform a matrix search process, while in the daytime, when the illuminance level is lower than the predetermined illuminance level, A GPS position detecting device, which performs an integration operation process having a long integration period, performs a matrix search process, and performs timing adjustment of a GPS signal and a code signal. 5. The image processing device according to claim 2, wherein the environment sensor is constituted by an image sensor, and the GPS position detecting device analyzes a spatial frequency distribution from a surrounding image picked up by the image sensor. The image processing circuit further includes a circuit, and when the surrounding image analyzed by the image processing circuit includes a large number of low frequency components, an integration operation process with a short integration period is performed to perform a matrix search process. If the surrounding image contains a lot of high frequency components, it is necessary to execute a long-time integration calculation process, perform a matrix search process, and perform timing matching between the GPS signal and the code signal. Characteristic G
PS position detector. 6. The GPS position detecting device according to claim 2, further comprising a use mode selection setting switch for selecting between outdoor and indoor, and a mode set by the use mode selection setting switch. A GPS position detecting device, wherein any one of the matrix search processes described above is selectively executed in accordance with the above, and the timing of the GPS signal and the code signal is adjusted.