JP2010038799A - Positioning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning apparatus for reducing a waste power consumption, and implementing a GPS positioning process at a proper interval even if a moving speed is changed while the apparatus is used. <P>SOLUTION: The positioning apparatus includes: a power supply battery; a first positioning means driven by the battery, receiving positioning radio waves from a GPS satellite, and measuring a current position; moving speed detecting means (S1, S2) for detecting the moving speed of an apparatus body in the positioning apparatus; a determining means (S3) for determining whether the moving speed detected by the moving speed detecting means is a predetermined value or less or not; and intermittently-driving means (S11-S15) for intermittently driving the first positioning means if the determining means determines that the moving speed is the predetermined value or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a battery-powered positioning device that measures the current position using GPS.

  2. Description of the Related Art GPS positioning devices that measure the current position using GPS (Global Positioning System) and perform navigation to a destination using information on the measured current position have been known. There is also known a portable GPS positioning device that has a battery and is miniaturized so that it can be carried.

  In addition, as a conventional technique related to the present invention, the following technique has been disclosed. For example, Patent Document 1 discloses a technology in which an in-vehicle navigation device has a vehicle speed sensor and does not update current position information even if GPS positioning is performed when the vehicle is stopped. Yes.

Further, in Patent Document 2, in the in-vehicle navigation device, when the GPS positioning is performed when the vehicle has a speed sensor and the vehicle is stopped, the current positioning estimation error is larger than the previous positioning estimation error. For example, a technique is disclosed in which the current position information is not updated.
Japanese Patent Laid-Open No. 5-26680 JP-A-8-271607

  A portable GPS positioning device driven by a battery can be used in a variety of situations, for example, while walking or moving a vehicle, but it cannot be used continuously for a long time because it relies on a battery for power. There are challenges. In particular, a process of receiving positioning radio waves from GPS satellites or performing positioning calculations based on positioning radio waves to obtain position information, consumes a large amount of power. Therefore, when the GPS positioning process is continuously performed, the power supply of the battery decreases relatively quickly.

  Therefore, instead of continuously performing GPS positioning processing, for example, a GPS positioning device that can be executed intermittently at predetermined time intervals, or the intermittent time of this GPS positioning processing can be set by the user Has also been developed. However, since the portable GPS positioning device can vary greatly during use, such as when used during walking to use while moving a vehicle, for example, the intermittent time of the GPS positioning process is set to be long in accordance with low-speed movement. If it does, the subject that a positioning interval will open too much at the time of high-speed movement will arise. On the contrary, if the intermittent time of the GPS positioning process is set to be short in accordance with the high speed movement, the positioning interval becomes unnecessarily narrow during low speed movement, resulting in a problem that wasteful power consumption increases.

  An object of the present invention is to provide a positioning device that can reduce wasteful power consumption and can execute GPS positioning processing at an appropriate interval even if the moving speed changes during use of the device. It is in.

In order to achieve the above object, the invention according to claim 1
A battery for power,
A first positioning means that is driven by the battery and receives a positioning radio wave from a GPS satellite to measure a current position;
In a positioning device equipped with
A moving speed detecting means for detecting the moving speed of the apparatus main body in the positioning device;
Discriminating means for discriminating whether or not the moving speed detected by the moving speed detecting means is a predetermined value or less;
An intermittent driving means for intermittently driving the first positioning means when the moving speed is determined to be less than or equal to a predetermined value by the determining means;
It is characterized by having.

The invention according to claim 2 is the positioning device according to claim 1,
The intermittent drive means includes
The driving interval of the first positioning means is changed in accordance with the speed not more than the predetermined value detected by the moving speed detecting means.

The invention according to claim 3 is the positioning device according to claim 1,
Equipped with a counting means for measuring time intervals,
The intermittent driving means is configured to drive the first positioning means based on the time interval set by the counting means.

The invention according to claim 4 is the positioning device according to claim 1,
A normal driving means for driving the first positioning means when the moving speed is not determined to be equal to or less than a predetermined value by the determining means;
The intermittent drive means includes
The normal driving means is configured to drive the first positioning means with an interval longer than the interval for driving the first positioning means.

The invention according to claim 5 is the positioning device according to claim 1,
In the intermittent period in which the driving of the first positioning means is stopped by the intermittent driving means, at least a part of the power supplied to the first positioning means is stopped.

The invention described in claim 6 is the positioning device according to claim 1,
It has sensor means for measuring the movement distance and movement direction of the apparatus main body, and the current position is obtained by displacing the previously measured position according to the movement distance and movement direction obtained based on the output of the sensor means. A second positioning means for obtaining
In the intermittent period in which the driving of the first positioning means is stopped by the intermittent driving means, the current position is measured by the second positioning means.

The invention according to claim 7 is the positioning device according to claim 6,
The sensor means includes
An acceleration sensor for detecting the acceleration of the apparatus body;
A direction sensor for detecting the orientation of the apparatus body;
Have
The second positioning means includes
First calculation means for calculating the moving speed of each direction component by integrating the acceleration of each direction component from the outputs of the acceleration sensor and the direction sensor;
A second calculating means for calculating the moving distance of each direction component by integrating the calculated moving speed of each direction component;
It is characterized by having.

The invention according to claim 8 is the positioning device according to claim 7,
The moving speed detecting means includes
It is characterized by comprising the sensor means and the first calculation means.

  According to the present invention, the GPS positioning process is intermittently performed during low-speed movement, so that wasteful consumption of battery power can be reduced, and even when the movement speed changes greatly during use of the device, There is an effect that the GPS positioning process can be executed at an appropriate interval according to the situation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an overall configuration of a navigation device as a positioning device according to an embodiment of the present invention.

  The navigation device 1 of this embodiment is, for example, a PND (Personal Navigation Device) that is miniaturized so as to be portable and that measures the current position and performs a simple navigation operation. As shown in FIG. 1, the navigation apparatus 1 obtains a GPS satellite receiving antenna 20 that receives positioning radio waves from a plurality of GPS satellites, and obtains a pseudorange and a satellite orbit from each GPS satellite from the positioning radio waves. The GPS satellite receiver 21 that calculates the current position of the device 1, the geomagnetic sensor 11 as a direction sensor that detects triaxial geomagnetism, and the acceleration sensor 12 that detects acceleration in the triaxial direction, and accurately detects the height difference. A barometric pressure sensor 13 for detecting the atmospheric pressure to obtain the information; a CPU 15 (central processing unit) for controlling the entire device; a display unit 14 for outputting a current position, a map display, a road guidance display, and the like; A movement amount calculation device 16 that exclusively performs calculation processing of the movement speed and movement amount from acceleration data and azimuth data, and an atmospheric pressure change calculation device 17 that calculates altitude from changes in atmospheric pressure. , A map database 18 in which a lot of map data blocked in a non-volatile memory is stored, a map information correction processing device 19 that performs correction processing when performing map display, and a power source 22 that supplies operating power to each unit Etc.

  The CPU 15 executes a control program stored in a non-illustrated non-volatile memory while using a RAM (Random Access Memory) not shown in a working memory space, and performs overall control processing of the device. It is.

  The movement amount calculation device 16 obtains triaxial acceleration from outputs of the geomagnetic sensor 11 and the acceleration sensor 12, and integrates acceleration data of at least two horizontal components over time excluding gravitational acceleration. It is the structure which calculates a moving speed (1st calculating means). Further, the moving speed data of each direction component is integrated over time, so that the moving amount of each direction component is calculated (second calculating means). The integration process employs a processing method in which acceleration data and velocity data sampled at a constant sampling frequency are added in a stacked manner, such as receiving positioning radio waves from GPS satellites. Compared with the calculation processing for positioning, the load is light and the power consumption is therefore low.

  For example, the atmospheric pressure change calculation device 17 calculates additional altitude information by detecting atmospheric pressure with respect to the GPS positioning information, or calculates a vertical movement speed and movement amount from the detected atmospheric pressure change. Is.

  The map information correction processing device 19 creates map data for display by, for example, connecting or rotating map information in units of blocks in the map database in accordance with changes in the display coordinate system. Further, for example, since it is assumed that the current position is at a position overlapping with the road during high-speed movement, the current position is corrected with a positioning error range based on the map information.

  The GPS satellite receiving antenna 20 includes a surface-type receiving antenna, a low noise amplifier, and a band pass filter, and receives a GPS power from the power supply 22 via the GPS satellite receiving device 21 to perform a receiving operation. .

  The GPS satellite receiver 21 demodulates a positioning code (for example, a C / A (Coarse and Acquisitions) code or a P (Precise) code) and a navigation message from the received radio wave of the GPS satellite, The current position is specified by performing a predetermined positioning calculation from the navigation message.

  The power source 22 is composed of a battery such as a primary battery or a secondary battery, for example. For example, the power supply 22 can turn on or off the GPS power to the GPS satellite receiving antenna 20 or the GPS satellite receiving device 21 by a power control signal from the CPU 15. In addition, when using with a vehicle, it is good also as a form which combined the structure which guide | induces and uses the battery power supply of a vehicle.

  Next, the operation of the navigation device 1 configured as described above will be described.

  FIG. 2 shows a flowchart of the positioning process executed by the CPU 15 and the movement amount calculation device 16.

  This positioning process is a process that is started when the operation mode of the navigation device 1 is shifted to the positioning mode, and is executed throughout the positioning mode. First, an outline will be described. In the positioning process, when the moving speed of the navigation device 1 is high, the navigation process is performed while the GPS positioning process is executed almost continuously. On the other hand, when the moving speed is low, the navigation process 1 is performed according to the speed. The GPS positioning process is intermittently executed at a certain time interval, and during the intermittent period when the GPS positioning process is stopped, the autonomous positioning process is performed based on other sensor outputs, and the positioning information is Navigation processing is performed.

  In the flowchart of FIG. 2, steps S1 to S3 are processing for confirming the speed of the navigation device 1, steps S4 to S8 are GPS positioning processing, and steps S9 and S10 are processing for displaying the current position. The navigation process, steps S11 to S15, and S19 are processes for measuring an intermittent period during which the GPS positioning process is stopped, and steps S16 to S18 are autonomous positioning processes.

  During high-speed movement, the loop processing of steps S1 to S10 is repeatedly executed, so that navigation processing that causes the GPS positioning processing to be performed almost continuously is executed, and the speed determination in steps S1 to S3 is performed at a low speed. If it is determined that the vehicle is moving, the loop processing of steps S1 to S3, S11 to S18, and S9 to S10 is repeatedly executed for a predetermined intermittent period, and navigation processing by autonomous positioning is performed. On the other hand, every time an intermittent period is counted, the process branches from step S15 to steps S19, S4 to S8, and intermittent GPS positioning processing is executed.

  Next, this positioning process will be described in detail.

[Movement speed confirmation process]
First, in steps S1 to S3, a process for confirming the moving speed of the navigation device 1 is performed. That is, in step S1, detection data is fetched from the geomagnetic sensor 11 and the acceleration sensor 12, and in the subsequent step S2, these detection data are sent to the movement amount calculation device 16 to calculate the movement speed of the navigation device 1.

  In the movement speed calculation process, for example, when moving the navigation apparatus 1 with a hand, a calculation process is performed such that speed fluctuations associated with hand shaking can be eliminated as noise. For example, a moving average of continuous speed data obtained for a certain period (for example, 2 seconds to 10 seconds) is calculated and obtained as a calculated value of the moving speed of the navigation device 1.

  When the moving speed of the navigation device 1 is calculated, it is determined in a subsequent step S3 whether or not the absolute value of the moving speed is greater than a predetermined speed Vth. For example, the predetermined speed Vth serving as the threshold value is set to a value for distinguishing between movement in an automobile and movement by walking.

  As a result, if the calculated movement speed of the navigation device 1 is greater than the predetermined speed Vth, it is determined that the vehicle is moving at high speed and the process proceeds to step S4 to perform the GPS positioning process almost continuously, but from the predetermined speed Vth. If it is not larger, the process is moving at a low speed, and the process proceeds to step S11 to perform the GPS positioning process intermittently.

[GPS positioning processing]
The GPS positioning process in steps S4 to S8 is executed as follows. First, power supply control is performed to turn on the GPS satellite receiver 21 with GPS power (step S4). Next, the GPS satellite receiver 21 performs positioning radio wave reception processing (step S5). Positioning information is acquired by causing the satellite receiver 21 to perform positioning calculation (step S6). Next, the current position information in the RAM is updated with this positioning information (step S7), and then the power supply control is performed to stop the power supply to the GPS satellite receiver 21 (step S8).

[Navigation process]
When the positioning process is performed and the process proceeds to the navigation process in steps S9 and S10, the process of sequentially superimposing the image data representing the current position on the display map information obtained from the map database 18 and the map information correction processing device 19 is performed. In step S9, the display data is sent to the display unit 14 for display output (step S10).

  When moving at high speed, such as when moving in an automobile, the loop processing of steps S1 to S10 described above is repeatedly executed by determining that it is high-speed movement in the processing of step S3, thereby performing GPS positioning processing almost continuously. Thus, a positioning interval corresponding to high-speed movement is maintained.

[Intermittent time measurement]
On the other hand, for example, when the moving speed becomes low, such as during walking, and the process proceeds to No in the determination process of step S3, the CPU 15 executes a process of measuring the intermittent time of steps S11 to S15. In the process of measuring the intermittent time, first, in step S11, it is determined whether or not the movement speed of the navigation device 1 calculated immediately before and the movement speed calculated before that are the same speed. In this determination process, it may be determined whether or not they are the same within a range including a certain allowable width.

  Here, when the speed has changed beyond a certain allowable range, the process proceeds to step S12, and an intermittent time corresponding to the speed is determined. Here, the intermittent time is determined to be a relatively long time if the speed is low, and a relatively short time if the speed is high. For example, a time interval corresponding to the speed may be calculated so that the GPS positioning process is performed at substantially constant distance intervals, and this time interval may be set as an intermittent time, or multiple steps of intermittent Time may be provided and the intermittent time may be set to increase stepwise as the speed decreases.

  When the intermittent time is determined in accordance with the calculated speed, a count upper limit value corresponding to the intermittent time is sequentially set in the internal counter (step S13), and the internal counter starts to be counted up (step S14). It is determined whether or not the upper limit has been reached (step S15). The count-up start command is ignored when the count-up is already being executed.

  If the counter value has not reached the upper limit value in the determination process in step S15, it is determined that the intermittent time has not yet elapsed, and the process proceeds to step S16 to perform the autonomous positioning process. On the other hand, if the upper limit value is reached, it is determined that the intermittent time has elapsed, and after the counter is cleared in step S19, the process jumps to step S4 to execute the GPS positioning process.

[Autonomous positioning processing]
If the intermittent time has not been reached and the process proceeds to step S16, first, the detection data of the atmospheric pressure sensor that has not yet been acquired in that step is acquired. In autonomous positioning, detection data of the geomagnetic sensor 11 and the acceleration sensor 12 are required to obtain a relative movement vector. Since these detection data have already been captured in the immediately preceding step S1, here, Loading is omitted.

  Next, in step S17, an arithmetic process for obtaining a relative movement vector is performed using the detection data acquired in the immediately preceding steps S16 and S1. Here, since the movement amount calculation device 16 has already calculated the velocity data of each direction component by the calculation process of step S2, in step S17, the velocity data of each direction component is integrated to obtain each direction component. Component movement distance data (relative movement vector) is calculated. Here, when calculating the movement distance in the vertical direction, a more accurate movement distance in the vertical direction may be calculated using the atmospheric pressure data.

  When the relative movement vector is obtained, in the subsequent step S18, the current position data is updated by adding the relative movement vector to the current position data stored in the RAM (not shown). To do. This updated current position data becomes the positioning information measured by the autonomous positioning process. When the autonomous positioning process in steps S16 to S18 is completed, the process jumps to step S9 and the navigation process based on the autonomous positioning is performed.

  By the above processing, during low-speed movement such as walking, the loop processing of steps S1 to S3 and S11 to S18 described above is repeatedly executed, so that GPS positioning is stopped during counting of the intermittent time. At the same time, the autonomous positioning process and the navigation process based on the positioning information are repeatedly executed. Further, every time the intermittent time is counted, one GPS positioning process (steps S4 to S8) is intermittently executed.

  As described above, according to the navigation device 1 of this embodiment, since the GPS positioning process is intermittently executed at a low speed movement, the GPS positioning interval is unnecessarily narrow, and the battery A situation in which the power is wasted is avoided. Thereby, the continuous use time of the navigation apparatus 1 can be extended.

  In addition, while GPS positioning processing is executed almost continuously during high-speed movement, GPS positioning processing is executed intermittently with an intermittent time corresponding to the moving speed during low-speed movement. The positioning interval does not open too much, and the positioning interval does not become unnecessarily narrow during low-speed movement, and GPS positioning processing can be executed at an appropriate positioning interval at any moving speed.

  In addition, during the intermittent period when GPS positioning processing is not executed, autonomous positioning processing based on the detection data of the acceleration sensor and the geomagnetic sensor is executed. For example, the map display is enlarged during walking to confirm fine movement Even if you want to, you can achieve a detailed navigation process.

  In order to obtain the relative movement vector of the navigation device 1, first, acceleration data of each direction component is obtained from the detection data of the acceleration sensor 12 and the geomagnetic sensor 11, and then these are integrated to obtain each direction component. Since the movement distance data of each direction component is obtained by integrating these, the movement vector can be obtained with a relatively small load, thereby reducing the power consumption. Autonomous positioning processing is realized.

  Further, it is necessary to determine the moving speed of the navigation device 1 in order to determine whether the GPS satellite receiver is normally driven or intermittently driven. The configuration for determining this moving speed is a geomagnetic sensor 11 necessary for autonomous positioning. And the configuration comprising the acceleration sensor 12 and the movement amount calculation device 16, the number of parts is reduced, the manufacturing cost is reduced, and the overall device is reduced compared to the case where a dedicated configuration for detecting the movement speed is added. Compactness can be achieved.

  In addition, this invention is not restricted to the said embodiment, A various change is possible. For example, in the above embodiment, the movement amount in the vertical direction is detected by the atmospheric pressure sensor 13 and the atmospheric pressure change calculation device 17, but this configuration may be omitted. Further, a dedicated movement amount calculation device 16 different from the CPU 15 is provided to calculate the movement speed and movement amount based on the outputs of the geomagnetic sensor 11 and the acceleration sensor 12, but this movement amount calculation device 16 is omitted. Then, the CPU 15 may be configured to perform the same calculation. Moreover, although the geomagnetic sensor was illustrated as a direction sensor, other direction sensors, such as a gyroscope, can also be used, for example.

  In the above embodiment, the power supply control by the CPU 15 (steps S4 and S8 in FIG. 2) stops the GPS power supply to the GPS satellite receiver 21 during the intermittent period when the GPS positioning process is not executed, thereby reducing power consumption. Although the configuration is shown, for example, the GPS satellite receiver 21 or the GPS satellite receiving antenna 20 is provided with a non-operation mode setting terminal for reducing power consumption, and the control signal is input to the setting terminal to intermittently It is also possible to adopt a configuration in which these power consumptions are reduced during the period.

  In addition, as a configuration of the GPS satellite receiver 21 and the GPS satellite receiving antenna 20, when the positioning operation is completed, the operation of the circuit that automatically performs radio wave reception and positioning calculation is stopped, and the power consumption in the circuit is reduced. It is also possible to adopt a configuration. With such a configuration, for example, the GPS satellite reception device 21 and the GPS satellite reception antenna 20 are operated during an intermittent period in which the GPS positioning processing is not performed without the CPU 15 performing the power control of steps S4 and S8 in FIG. Power consumption can be automatically reduced.

  In the above-described embodiment, the configuration in which the GPS positioning process is executed almost continuously during high-speed movement has been described. However, the GPS positioning process may be executed with a short intermittent period even during high-speed movement.

  In the above embodiment, the navigation device 1 is operated by the battery power source 22 even while the vehicle is moving. However, when the vehicle is moving, the GPS satellite receiving device 21 and the GPS satellite receiving antenna 20 are guided by power from the vehicle battery. The battery may be driven, so that it is possible to avoid significant battery power consumption even if the GPS positioning process is continuously executed.

  In addition, the details shown in the embodiment, such as the configuration of the navigation device and the processing method of the positioning process, can be changed as appropriate without departing from the spirit of the invention.

It is a block diagram which shows the whole structure of the navigation apparatus as a positioning apparatus of embodiment of this invention. It is a flowchart which shows the process sequence of the positioning process performed by the navigation apparatus of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 11 Geomagnetic sensor 12 Acceleration sensor 15 CPU
16 Movement amount calculation device 18 Map database 20 GPS satellite reception antenna 21 GPS satellite reception device 22 Power supply

Claims (8)

A battery for power,
A first positioning means that is driven by the battery and receives a positioning radio wave from a GPS satellite to measure a current position;
In a positioning device equipped with
A moving speed detecting means for detecting the moving speed of the apparatus main body in the positioning device;
Discriminating means for discriminating whether or not the moving speed detected by the moving speed detecting means is a predetermined value or less;
An intermittent driving means for intermittently driving the first positioning means when the moving speed is determined to be less than or equal to a predetermined value by the determining means;
A positioning device characterized by comprising: The intermittent drive means includes
2. The positioning apparatus according to claim 1, wherein a driving interval of the first positioning means is changed according to a speed equal to or less than the predetermined value detected by the moving speed detecting means. Equipped with a counting means for measuring time intervals,
The positioning device according to claim 1, wherein the intermittent driving means is configured to drive the first positioning means based on the time interval set by the counting means. A normal driving means for driving the first positioning means when the moving speed is not determined to be equal to or less than a predetermined value by the determining means;
The intermittent drive means includes
2. The positioning apparatus according to claim 1, wherein the normal positioning unit drives the first positioning unit with an interval longer than an interval for driving the first positioning unit.   In an intermittent period in which the driving of the first positioning means is stopped by the intermittent driving means, at least a part of the power supplied to the first positioning means is stopped. Item 5. The positioning device according to item 1. It has sensor means for measuring the movement distance and movement direction of the apparatus main body, and the current position is obtained by displacing the previously measured position according to the movement distance and movement direction obtained based on the output of the sensor means. A second positioning means for obtaining
2. The positioning device according to claim 1, wherein a current position is measured by the second positioning means during an intermittent period in which the driving of the first positioning means is stopped by the intermittent driving means. The sensor means includes
An acceleration sensor for detecting the acceleration of the apparatus body;
A direction sensor for detecting the orientation of the apparatus body;
Have
The second positioning means includes
First calculation means for calculating the moving speed of each direction component by integrating the acceleration of each direction component from the outputs of the acceleration sensor and the direction sensor;
A second calculating means for calculating the moving distance of each direction component by integrating the calculated moving speed of each direction component;
The positioning device according to claim 6, further comprising: The moving speed detecting means includes
8. The positioning device according to claim 7, comprising the sensor means and the first arithmetic means.

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