JPH08297033A - Navigation device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a navigation device that suppresses the influence of gravitational acceleration and can accurately detect a relative position even when a vehicle is inclined on a slope or the like [Configuration] Relative position detection device 4 Sends the velocity obtained by integrating the sensor output detected by the acceleration sensor 8 and the angular velocity detected by the gyro sensor 7 to the control device 3. GPS
The device 2 receives the GPS signal and sends accurate absolute position information to the control device. The control device calculates the current position based on the information from both devices 2 and 4. Furthermore, the tilt sensor 1
5, the gravitational acceleration component included in the sensor output of the acceleration sensor is corrected based on the sensor output, accurate velocity (distance) information is obtained, and the accuracy of relative position detection is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device.

[0002]

2. Description of the Related Art Navigation devices mounted on automobiles and the like are generally GPS (Global Position).
ing system) is used to detect the absolute position of the vehicle, synthesize it with map data stored in advance, and display the current position of the vehicle.

As is well known, although GPS can accurately measure an absolute position in real time, it cannot receive radio waves from a GPS satellite due to underpass, tunnel, weather conditions, etc. (reception sensitivity is low. ) Location,
There is a problem that radio waves are reflected like in a valley of a building and accurate measurement cannot be performed.

Therefore, in order to make up for such a drawback, a hybrid navigation is commonly used in combination with self-contained navigation in which vehicle speed (distance) information and direction information are detected to detect the relative position of the vehicle. That is, when GPS is functioning, the absolute position of the vehicle is detected based on the received signal, and when GPS is not functioning (when radio waves cannot be received), the absolute position of the vehicle when it cannot be received due to self-contained navigation. Is used as a reference position, and the current position of the automobile is calculated by calculating the relative position from the reference position.

The vehicle speed information is generally detected by using vehicle speed pulses used in a vehicle speedometer. A geomagnetic sensor, an optical fiber gyro, a ceramic gyro, or the like is used for the azimuth. However, the above-mentioned method using the vehicle speed pulse has a problem in that there is an error due to mounting restrictions, tire wear, and the like, and the output format is not uniform among the vehicle types, and the versatility is poor.

Therefore, in order to solve these problems,
Instead of the vehicle speed pulse system, it is also considered that an acceleration sensor is used and the sensor output (acceleration) is integrated to detect the speed (distance) (JP-A-5-10).
774, etc.).

[0007]

However, in the method using the acceleration sensor described above, the problems such as errors due to tire wear have been solved, but the following new problems occur. That is, the acceleration sensor has a direction of detection sensitivity, and there is a problem that the output sensitivity greatly varies depending on the mounting angle of the sensor. Therefore, the mounting process must be performed accurately, and the work becomes complicated.

Even if the acceleration sensor is mounted with high accuracy, the acceleration sensor mounted on the vehicle is affected by the roll pitch. For example, movement on a slope is affected by gravity, so that the acceleration is the same. However, the sensor output is different when traveling on level ground, moving uphill, and moving downhill. In addition, centrifugal force is applied during turning (turning), and even with the same acceleration, an output different from the sensor output during straight movement is obtained. As described above, even if the acceleration is the same, the sensor output varies depending on the running posture of the vehicle and the like, and thus an error occurs in speed information obtained by integrating the sensor output.

The present invention has been made in view of the above background, and an object of the present invention is to solve the above problems and to exert an influence of acceleration other than the traveling direction, which is caused by a roll pitch generated during traveling. Can be suppressed as much as possible (eliminating the error component), and the velocity based on the acceleration can be accurately obtained regardless of the posture of the moving object (vehicle) when moving on a slope or a curve. It is an object of the present invention to provide a navigation device that can perform relative position detection with high accuracy and that can relatively easily and accurately attach an acceleration sensor.

[0010]

In order to achieve the above-mentioned object, in a navigation device according to the present invention, a moving direction of a moving object for obtaining a relative position from a reference position,
Relative position detection means for extracting data regarding the movement amount,
In a navigation device comprising map information storage means having map information, display means for displaying the map information and the current position of the vehicle, and control means for performing the above control,
The relative position detection means is premised to have an acceleration sensor arranged so as to have high sensitivity in the traveling direction, and a detection means for detecting information on the traveling direction such as a gyro sensor. Then, an inclination detecting device including an acceleration sensor arranged so as to have high sensitivity in the direction of gravity, and an acceleration sensor for detecting the acceleration in the traveling direction which is the output of the relative position detecting device using the output of the inclination detecting device. And a correction means for performing a correction for removing an error component based on the inclination included in the sensor output of (1).

Further, a centrifugal force detecting acceleration sensor arranged so as to have high sensitivity in a lateral direction orthogonal to a traveling direction with respect to a navigation device based on the same premise as described above, and the centrifugal force detecting acceleration sensor. The output of the relative position detecting device is used to correct the error based on the centrifugal force included in the sensor output of the acceleration sensor that detects the acceleration in the traveling direction. (Claim 2)

In any case, in order to improve accuracy, an absolute position detecting means for obtaining an absolute position, such as GPS, is provided, and the control section controls the relative position detecting means and the absolute position detecting means. It is to add a function of determining the current position of the vehicle based on the output signal (claim 3).

Preferably, the acceleration sensor is mounted on the moving object via an attitude control device,
The attitude control device movably supports the acceleration sensor based on a predetermined rotation axis or a fulcrum, and
The relative attitude of the acceleration sensor with respect to the moving object is changed in a direction opposite to the change of the moving attitude of the moving object (claim 4).

More preferably, the attitude control device is
A gimbal structure that rotates appropriately around two orthogonal rotation axes may be provided, and a damper structure may be provided in the pitch direction of the moving object (Claim 5), or the roll direction and the pitch of the moving object. For the direction
Each of them has a damper structure (claim 6). Furthermore, the posture control device further includes a movement stop mechanism that suppresses movement of the acceleration sensor, and a mode in which the relative posture of the acceleration sensor is changed in accordance with the posture change of the moving object, and a relative posture. It is more preferable to include a switching means for switching the mode for fixing the above (Claim 7).

[0015]

The sensor output of the acceleration sensor installed so as to have high sensitivity to the traveling direction corresponds to the true acceleration which is the change in the moving speed when the moving object is horizontal and straight ahead. Will be things. However, in reality, when the vehicle is tilted such as moving on a slope, it is affected by the gravitational acceleration and also receives a centrifugal force generated when the vehicle bends, so that the sensor output has a value including the gravitational acceleration and the centrifugal force.

Therefore, according to the first aspect of the present invention, since the sensor output corresponding to the inclination is obtained by the inclination detection device, the correction value is obtained by the correction means based on the sensor output, and based on the sensor output value of the acceleration sensor. Correct the data. This makes it possible to extract the true acceleration in the traveling direction (necessary for calculating the moving speed and distance information). In addition,
The correction process may be performed directly on the sensor output, but may be performed on speed information or distance information calculated based on the sensor output (acceleration) (indirectly correcting the sensor output). .

According to the second aspect of the invention, since the lateral acceleration can be detected by the centrifugal force detecting acceleration sensor, the centrifugal force during rotation, which is included in the traveling direction acceleration sensor, as in the above case. It is possible to separate the acceleration component caused by. Therefore, it is possible to obtain an accurate true acceleration, an accurate moving distance and the like based on the accurate acceleration, and an accurate relative position of the moving body is calculated.

Further, when configured as in claims 4 to 7,
The posture of the acceleration sensor is controlled, and the acceleration sensor maintains a posture in which the detection axis (high sensitivity direction) and the gravity direction are always orthogonal (the minimum sensitivity direction matches the gravity direction). Therefore, the influence of gravitational acceleration on the acceleration sensor is minimized, and more accurate measurement can be performed by performing the above-mentioned correction process thereafter. In particular, when the inventions are set forth in claims 5 and 6,
Vibration in a predetermined direction is absorbed by the damper structure, and the error included in the sensor output is reduced as much as possible. Claim 7
In such a case, the sensor output is normally prevented from containing an error component in accordance with the operating principles described in claims 4 to 6, but the attitude control device may run away due to resonance. When normal operation cannot be performed due to some reason, the posture control can be stopped, and thus the error component is removed only by the above-described correction process. Therefore, by switching between the two modes depending on the situation, the optimum processing is always performed, the error component is removed, and accurate measurement (relative position detection) is performed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a navigation device according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention. As shown in FIG. 1, a GPS signal from an artificial satellite is received by an antenna 1 and the received signal is given to a GPS receiving section 2. I am trying. The GPS receiving device 2 calculates the latitude and longitude of the current position by a predetermined calculation process based on the received signals from a plurality of artificial satellites received at the same time, and transfers them to the control device 3. Since the calculation process is publicly known, a detailed description thereof will be omitted.

The control device 3 is also supplied with a detection signal from a relative position detection device 4 (a specific configuration will be described later) for self-contained navigation. Then, the control device 3 calculates the current position of the vehicle using the absolute position information based on the GPS and the relative position information based on the relative moving direction and the distance from the previous position given from the relative position detection device 4. It has become.

That is, the control device 3 prioritizes the input from the GPS receiving device 2 when there is an input, and the latitude /
The position display device is accessed by accessing the map information storage unit 5 based on the absolute position of the longitude, reading out the corresponding map, and superimposing a mark such as a pointer indicating the current position of the vehicle on the existing position on the map. The output is displayed on 6.

On the other hand, when the input signal from the GPS receiving device 2 disappears, based on the input signal from the relative position detecting device 4 (information relating to the moving direction and moving distance), the input signal (relative movement) with respect to the previous existing position is detected. The position is added (the moving distance is added to the moving direction (moving direction)) to obtain the current position, and the current position thus obtained is output and displayed on the position display device 6 in the same manner as described above. In the above explanation, GP
Although the S side is preferentially used, the present invention is not limited to this, but the output from the relative position detection device 4 is basically used, and the correction may be appropriately performed based on absolute position information such as a GPS signal. good.

As the above-mentioned antenna 1, for example, a directional (weak) orthogonal dipole antenna, a helical antenna, a plane antenna, or the like is used. Also,
A CD-ROM, an IC card, or the like can be used as the map information storage unit 5. Further, as the position display device 6, a liquid crystal display is preferable because it is small, but a CRT display may be used.

Next, the structure of the relative position detecting device 4 will be described. Angular velocity, which is reference data for detecting the moving direction (traveling direction) of a vehicle (own vehicle) which is a moving object on which the present navigation device is mounted. A gyro sensor 7 for detecting the acceleration and an acceleration sensor 8 for detecting an acceleration which is reference data for obtaining the moving distance. As the gyro sensor 7, various sensors such as a geomagnetic gyro, an optical fiber gyro, and a piezoelectric vibration gyro can be used. Then, basically, the moving direction is obtained by integrating the angular velocity information obtained from the gyro sensor 7 and converting it into angle information, and the function of converting the angle information is also given to the relative position detection device 4 side. Alternatively, it may be provided on the control device 3 side.

As the acceleration sensor 8, various types such as a capacitance type or a piezo type semiconductor acceleration sensor or a piezoelectric element type can be used. In this embodiment, a piezo type semiconductor acceleration sensor is used, and the acceleration sensor 8 outputs a voltage corresponding to the acceleration. Furthermore, the speed of the vehicle is obtained by integrating the acceleration detected by the acceleration sensor, and the moving distance is obtained by further integrating it. Then, the integration (second order integration) process is performed by the relative position detection device 4 or the control device 3 as in the angle calculation. That is, one of acceleration information, speed information, and distance information is output from the relative position detection device 4, and the control device 3 performs an integration process on the given information as necessary to obtain desired data. It has become.

On the other hand, an example of a specific detection algorithm for detecting the relative position is as follows. That is, it is assumed that the position of the starting point and the moving direction are known. Then, if the velocity v and the direction θ can always be detected, the current position can be obtained by calculating the following equation for each unit time.

X = X1 + vcos θ Y = Y1 + vsin θ where (X, Y): current position (X ', Y'): previous position Then, the speed v is obtained by integrating the output of the acceleration sensor 8 as described above. The angle θ can be obtained by changing the direction and angle at the starting point. Here, the position and direction at the starting point are obtained from the GPS azimuth information, and the change in angle is obtained from the output of the gyro sensor 7.

In the present embodiment, the arithmetic processing is performed in the control device 3, and the relative position detection device 7 outputs the angles and accelerations which are the outputs of the sensors 7 and 8. .

Further, in this embodiment, correction is performed when calculating the speed information from the sensor output of the acceleration sensor 8 based on the absolute position information obtained from the GPS signal. That is, as shown in FIG. 2, absolute position time series data (X (nΔ
t), Y (nΔt)) is sent to the differential processing unit 10 and is differentiated there, and the speed time series data V1 (nΔt)
To calculate.

On the other hand, the output A (nΔt) of the acceleration sensor 8 for detecting the acceleration generated in the traveling direction of the vehicle is given to the integration processing section 11, and the integration processing is performed there by a preset function to determine the relative speed. Series data V2 (nΔ
Calculate t).

Then, the data V1 obtained during the unit time
(NΔt) and V2 (nΔt) are given to the integral function conversion unit 12, and maximum likelihood estimation is performed there, and V1 (nΔt) / V2
The maximum likelihood value α in the distribution of (nΔt) is obtained and transferred to the integration processing unit 11. In the integration processing unit 11, the sensor output A (nΔt) of the acceleration sensor 8 is integrated as described above. Further, the integration value obtained in this way is multiplied by the maximum likelihood value α as a correction value. I have to. As a result, the sensor mounting error and the secular change error are corrected. The correction process based on the GPS signal does not necessarily have to be performed, and the acceleration sensor output may be integrated to obtain the speed.

Here, in the present invention, an inclination sensor 15 is added as shown in FIG.
The error with respect to the sensor output of is corrected.
That is, when the own vehicle is moving on a slope, the acceleration sensor 8 is further added with the gravitational acceleration in addition to the acceleration due to the change in the moving speed, so that there is an error due to the gravitational acceleration. The error increases as the slope of the slope increases.

Therefore, a correction table 16 for the gravitational acceleration error component based on the posture information of the acceleration sensor 8 is created in advance. Then, the output of the tilt sensor 15 is given to the correction value determination unit 17, and the correction value determination unit 17 refers to the correction table 16 based on the input data to read the corresponding correction value and subtract the correction value. Transfer to the container 18. The output of the integration processing unit 11 is also given to the subtractor 18. Then, the subtracter 18 executes "integral value-correction value", and the calculation result is calculated by the integral function conversion unit 1
Send to 2. That is, since the error due to the gravitational acceleration is an offset error of the relative velocity, the gravitational acceleration error is calculated by subtracting the correction value corresponding to the error estimated as described above from the calculated relative velocity. Can be corrected. In this embodiment, the correction table 16, the correction value determination unit 17, and the subtractor 18 constitute a correction means.

In this embodiment, the inclination sensor 15 is of the same type as the acceleration sensor 8 installed for speed detection. As shown in FIG.
15 are integrated. That is, both sensors 8, 15
Are configured using piezoresistive semiconductor sensors having the same characteristics, and are mounted in one housing 20.

Each of the sensors 8 and 15 has a weight portion 8a and 15
a is cantilevered through the beam portions 8b and 15b, and the piezoresistive effect elements 8c and 8c are attached to the beam portions 8b and 15b.
15c is attached and configured. When acceleration is applied to the weight portions 8a and 15a, the weight portions 8a and 15a
15a swings around the beam portions 8b and 15b. And
The swaying angle (swaying angle) increases as the acceleration increases, and when the swaying angle increases, the amount of bending of the beam portions 8b and 15b also increases, and the attached piezoresistive effect elements 8c and 15c are also greatly distorted. , The resistance value changes greatly.
By converting the change in the resistance value into a voltage, a voltage value corresponding to the acceleration can be output, and the acceleration is detected from the voltage value.

The sensors are arranged so that the directions in which the detection sensitivity is good intersect at right angles. That is, assuming that the traveling direction and the gravitational direction are respectively indicated by the one-sided arrows in the figure, the acceleration sensor 8 has the weight portion 8a in the housing 2.
The tilt sensor 15 is arranged so as to be perpendicular to the bottom surface 20a of the housing 0, and the weight portion 15a of the tilt sensor 15 is parallel to the bottom surface 20a of the housing 20.

As a result, the tilt sensor 15 sways as shown by the double-headed arrow in the figure, so that the detection sensitivity to the acceleration in the vertical direction, that is, the same direction as the gravity direction becomes the highest, and the output corresponding to the tilt is obtained. Therefore, the gravitational acceleration is detected. Further, in the present embodiment, the output from the tilt sensor 15 is an output voltage according to an error associated with gravitational acceleration, and is not a specific tilt angle. Therefore, along with this, the above-mentioned correction table stores the output voltage from the tilt sensor 15 and the correction value at that time as a pair.

The correction value is obtained by the table reference method in this embodiment because the output voltage of the tilt sensor 15 and the correction value are not in a perfect proportional relationship, so that more accurate correction control is performed. is there. Therefore, when the accuracy may be lowered to some extent according to the required specifications, the correction value is determined by performing the calculation processing on the sensor output given by the correction value determination unit 17 according to the calculation formula obtained in advance. May be. Even in that case, the accuracy is improved as compared with the conventional uncorrected one. Since the sensors of the same type are used in this embodiment, their output characteristics are almost the same, so that it is possible to calculate an approximate correction value by a relatively simple formula.

Further, as in the present embodiment, both the acceleration sensor and the inclination sensor are constituted by using a small-sized and inexpensive semiconductor type acceleration sensor. Therefore, even if the inclination sensor is provided and a correction function is added, the whole apparatus is conventional. It doesn't grow much larger than the ones.

Further, in the present embodiment, the acceleration sensor 8 and the tilt sensor 15 are mounted and integrated in the same housing 20, so that the acceleration and the tilt at the same point can be detected, so that the measurement accuracy is improved and the housing is also improved. If the relative positional relationship (orthogonal direction) in the high-sensitivity direction is accurately set when the body 20 is installed in the body 20, the posture of the housing 20 may be taken into consideration when the body 20 is actually installed, It's relatively easy.

FIG. 4 shows a second embodiment of the present invention.
Unlike the above-described embodiment, this embodiment is intended to eliminate the error caused by the lateral acceleration other than the traveling direction axis, which is caused by the turning operation of the vehicle or the like. That is, when the vehicle is traveling on a curved or curved road, a centrifugal force is applied to the vehicle and the acceleration sensor 8, and a lateral acceleration based on the centrifugal force is applied.
The output of the acceleration sensor 8 has a value that includes the acceleration (error) in the lateral direction (centrifugal force direction) in addition to the acceleration component due to the original speed change.

Therefore, in this embodiment, an acceleration sensor 25 having a centrifugal force direction perpendicular to the traveling direction of the vehicle as a detection axis is provided, and the acceleration sensor 2 for detecting the centrifugal force direction is provided.
The sensor output of No. 5 is used to remove the error due to the centrifugal force.

That is, assuming that the true acceleration value generated in the front-rear direction (traveling direction) is G _front-rear and the true acceleration value generated in the left-right direction (centrifugal force direction) is G _left-right , each of the sensors 8, 25. The sensor output of is a value obtained by combining the above two values. That is, the sensor output G _FE of the acceleration sensor 8 for the front-back direction (travel direction) is G _FE = G _front - _back + αG _left-right (1). Here, α is the other axis sensitivity constant specific to the sensor.

Similarly, the acceleration sensor 25 for detecting the centrifugal force
Output G _LR is G _LR = G _left / _right + αG _{front / back} (2).

From the above (1) and (2), the following equation holds.

[0046]

[Equation 1] On the other hand, if the vehicle is turning, its turning radius is r0
, G _{left and right as} centrifugal force are G _left and _right = r0 ω ² (4), the angular velocity ω of the vehicle can be approximated by the output ω 0 of the gyro, and the turning radius r 0 is It can be approximately calculated from the output by the following formula.

[0047]

[Equation 2] The radius R obtained by this calculation has a larger difference from the actual radius r0 as the distance increases, but since the relative ratio can be ignored compared to the acceleration, R is r0.
Can be regarded as Therefore, _{before and after} the finally obtained acceleration G in the true traveling direction is obtained by the following equation.

[0048]

(Equation 3) A correction device for removing the error for implementing the above principle is shown in FIG. signal·
The configuration will be described in the order of the correction process. First, the sensor output G _FB of the acceleration sensor 8 for the traveling direction is given to the integrator 26, where it is integrated over time, and the calculation result is given to the turning radius calculation unit 27. Turning radius calculation unit 27
Is the sensor output G _{LR of the} acceleration sensor 25 for detecting centrifugal force.
_Is also given, and the output of G _LR and the integrator 26 is given by the above equation (5).
And the turning radius R of the vehicle is calculated based on the sensor output.

The calculated radius of gyration R is given to the centrifugal force direction acceleration component calculating section 28 together with the gyro output ω 0, and the equation (4) is calculated there to calculate the true centrifugal force G _right and _left .

The outputs of both sensors 8 and 25 are given to the multiplier 29 after being subjected to the arithmetic processing of "G _FB -G _LR " by the adder / subtractor, and multiplied by the coefficient (1 / (1-α)). Then, the obtained calculation result is given to the adder, and is added together with the values G _{left and right} obtained by the centrifugal force direction acceleration component calculation unit 28. Then, the added value is sent to the integration processing unit 30 and is integrated, and as a result, the equation (6) is executed, and the true speed G _front- back direction is obtained. In addition,
The other structure and effects are the same as those of the first embodiment described above, and therefore the same reference numerals are given and detailed description thereof is omitted. The second embodiment and the above-described first embodiment may be combined, of course, and in such a case, the effects of both the inclination and the centrifugal force can be suppressed, so that the accuracy is further improved.

FIG. 6 shows a third embodiment of the present invention.
In this embodiment, the mounting mechanism of the acceleration sensor 8 is improved. That is, in each of the above-described embodiments, the acceleration sensor 8 is fixedly installed, and for example, when the vehicle tilts when moving on a slope, the acceleration sensor 8 is also tilted at the same angle as the vehicle with respect to the gravity direction. However, in the present embodiment, even if the vehicle leans, the acceleration sensor does not easily follow, and the standing state in the same direction as the direction of gravity is maintained so that the output itself of the acceleration sensor is less affected by the gravitational acceleration. As a result, the relative position becomes two-dimensional information, so that an error caused by using the three-dimensional information as the two-dimensional information, which is one of the error factors of the current relative position detecting device, can be suppressed.

Specifically, first, the housing 32 having the built-in acceleration sensor 8 is movably supported. In the illustrated example, the housing 3 is connected to the rotary shaft 33 via a connecting plate 34 having a substantially triangular shape in a plane.
Attach 2. The rotary shaft 33 is rotatably attached to the machine frame 35. As a result, the rotating shaft 33
The housing 32 is integrated with the housing 32, and when the rotating shaft 33 rotates, the housing 32 (acceleration sensor 8) also rotates by the same angle. Further, a weight 36 is attached to the bottom surface of the housing 32.

Therefore, when the machine frame 35 is fixed to the vehicle, the machine frame 35 is accompanied by the inclination of the vehicle on a slope or the like.
Also tilts. However, under the influence of gravity, the line connecting the rotating shaft 33 and the weight 36 is corrected to always be in the direction of gravity, and the rotating shaft 33 also rotates. As a result, the posture of the acceleration sensor 8 becomes constant in the gravity direction. The weight 36 is installed in order to ensure that the posture of the acceleration sensor 8 has a predetermined relationship with the direction of gravity, and the housing 32 itself has a certain weight.
It functions even if the weight 36 is not provided. As described above, since the influence of the inclination is less likely to occur, the error component included in the sensor output is reduced, and by performing the above-described signal processing thereafter, it is possible to detect the relative position with higher accuracy. In addition,
Since the signal processing for the output of the acceleration sensor 8 and other configurations are the same as those in the above-described embodiments, detailed description thereof will be omitted.

FIG. 7 shows a fourth embodiment of the present invention. The third embodiment described above has a uniaxial pendulum structure that rotates about the rotation axis, so that the error is absorbed in a one-dimensional direction, such as suppressing the effect of inclination on a slope, but in the present embodiment, the It enables error absorption in the dimensional direction. That is, as shown in the figure, a housing 32 (where a weight is attached to the bottom of the housing 32 as needed) on which the acceleration sensor 8 is mounted is mounted on the ceiling portion of the machine casing 35 via a connecting rod 37. Connected. The upper end of the connecting rod 37 can freely rotate around the connection point (free pendulum structure). Therefore, the housing 32 becomes movable in the front-rear direction and the left-right direction as shown by the arrow in the figure, and the minimum sensitivity direction of the built-in acceleration sensor 8 and the gravitational acceleration direction can always be made to coincide with each other, and the gravitational acceleration due to the inclination is increased. It is possible to minimize the occurrence of errors such as the influence of. Since the signal processing for the output of the acceleration sensor 8 and other configurations are the same as those in the above-described embodiments,
Detailed description thereof will be omitted.

FIG. 8 shows a fifth embodiment of the present invention. This embodiment is another construction which adopts a construction in which the acceleration sensor is hard to tilt like the third and fourth embodiments. .
As shown in the drawing, a gimbal structure is formed by combining an independent rotating shaft 41 and another rotating shaft 42 subordinate thereto, and the center of the gimbal structure 43, that is, both shafts 41, 4 are formed.
A housing 32 having the acceleration sensor 8 built therein is installed on the intersection of the two. As a result, the acceleration sensor 8 is controlled so as to always maintain the same posture in the three-dimensional space, and has a constant posture in the traveling direction. Therefore, when adjusting so that the orientation of the acceleration sensor 8 is correct during mounting,
The rotation axes 41 and 42 are appropriately rotated, and thereafter the posture of the acceleration sensor at the time of initial setting is maintained.

Further, in this embodiment, the viscous function i (a1) of the variable of acceleration a1 with respect to the rotation axis 41 in the pitch direction is used.
A damper structure 45 having a is added. With such a configuration, it is possible to minimize the occurrence of an error due to the roll operation by the damper structure 45 and minimize it.

FIG. 9 shows a sixth embodiment of the present invention, which has the fourth embodiment as a basic configuration. That is, the gimbal structure 43 holds the acceleration sensor, and
It is common in that a predetermined damper structure 45 is mounted on. Here, in the present embodiment, the damper structure 46 having the viscous function j (a2) of the variable of the acceleration a2 is added to the rotating shaft 42 in the roll direction as well, so that the damper structure 46 can prevent the error due to the pitch operation. Can be absorbed by. As described above, by providing the mechanism for suppressing the error generation in the preceding stage of the signal processing, it is possible to detect the relative position with higher accuracy. In addition, other configurations and operational effects are the same as those in the above-described embodiments.

FIG. 10 shows a seventh embodiment of the present invention. Also in this embodiment, similar to the fifth and sixth embodiments described above,
Case 3 with built-in acceleration sensor 8 in gimbal structure 43
It is supposed to support 2. In the present embodiment, the shafts 41 and 42 that support the gimbal structure 43 are rotatably attached to the base 47. This base 47 is
A hemispherical recess 47a is formed on the upper surface thereof, and the lower half of the gimbal structure 43 is inserted into the recess 47a.

A spherical permanent magnet 48 is arranged in the recess 47a. As a result, the permanent magnet 48
Can freely move in the recess 47a and is positioned at the lowermost position on the absolute axis with respect to the ground by receiving gravity. That is, if the base 47 is installed horizontally, it is located at the bottom of the recess 47a of the hemisphere as shown in the figure, but if it is inclined, the lowest position of the inner surface of the recess 47a. Will be moved to.

Further, an electromagnet 49 is attached to the lower end of the gimbal structure 43. The electromagnet 49 generates a magnetic field when energized by a power source (not shown),
And suction power is generated. Although not shown, the permanent magnet 48 is kept at the lowermost position by an appropriate guide means so as not to separate from the recess 47a, whereby the permanent magnet 48 receives the attractive force generated by the energization. The electromagnet 49 is attracted to the permanent magnet 48, and the shafts 41 and 42 rotate accordingly. Then, since the electromagnet 49 is located directly above the permanent magnet 48, the line connecting the two 49, 48 coincides with the direction of gravity. Therefore, if the minimum sensitivity direction of the acceleration sensor 8 is previously aligned with the diameter direction of the gimbal structure 43 passing through the permanent magnet 48, when the permanent magnet 48 and the electromagnet 49 coincide with the gravity direction as described above, the acceleration sensor The minimum sensitivity direction of 8 also coincides with the gravity direction.

Therefore, even if the inclination adjustment (horizontal installation) when mounting the base 47 to the vehicle is relatively rough, the acceleration sensor 8 is affected by the gravitational acceleration by energizing the electromagnet 49. It is possible to have a difficult predetermined posture. Therefore, the mounting work to the vehicle becomes easy. Then, during the actual operation, the power supply to the electromagnet 49 is cut off. Then, when the base 47 is tilted by the gimbal structure 43 according to the tilt of the vehicle or the like, the base 32 is appropriately rotated around the shafts 41 and 42, and the housing 32 (acceleration sensor 8) assumes the posture at the time of initial setting due to the energization. maintain.

In this embodiment, the permanent magnet 48 is moved so that it is always at the lowermost position. However, the present invention is not limited to this, and the permanent magnet 48 is placed at a predetermined position (usually the recess 4).
It may be fixed to the bottom of 7a). With such a configuration, when the base 47 is attached to the vehicle, it is necessary to precisely adjust the level, but if the base 47 can be installed in a predetermined state, the electromagnet 49 should be energized in the same manner as above. Thus, the acceleration sensor 8 can have a desired posture. In this method, the installation of the base 47 is more complicated than that in the above embodiment, but the configuration is simple.

FIG. 11 shows an eighth embodiment of the present invention. As shown in the figure, the third embodiment shown in FIG.
Based on the embodiment, a mechanism for forcibly stopping the rotation of the rotating shaft 33 is provided. That is, in the third embodiment, since it has a pendulum structure, in a special case (for example, when an error in the frequency that causes resonance is input), there is a mode to increase the error, and the operation may become unstable. is there. Therefore, the operation of the third embodiment is normally performed by the pendulum structure, and the rotation shaft 33 is locked by the input of an external signal to prevent an increase in error.

That is, the electromagnetic brake 50 is attached to one end of the rotary shaft 33. The electromagnetic brake 50 generates a braking force by energization from the electromagnet driving device 51, and the rotating shaft 33
The rotation axis 33 rotates in accordance with the operating principle shown in the third embodiment, and the posture of the built-in acceleration sensor 8 is kept in a predetermined state. Keep on. Then, when a predetermined external signal is input to the control unit 52, the control signal from the control unit 52 is transmitted to the electromagnet driving device 51, and the electromagnetic brake 5
0 comes to work. Then, the acceleration sensor 8 holds the posture at that time and functions as a normal device as shown in the first and second embodiments.

Since the other construction is the same as that shown in the third embodiment, the same reference numerals are given and the description thereof is omitted. Further, it goes without saying that such a structure can be applied to, for example, the structure of the free pendulum structure shown in FIG.

[0066]

As described above, in the navigation device according to the present invention, the sensor output of the acceleration sensor for detecting the acceleration in the traveling direction is detected based on the outputs of the inclination detection device and the acceleration sensor for centrifugal force detection. Since the correction is performed directly or indirectly, the gravitational acceleration due to the inclination of the moving object included in the sensor output and the component based on the centrifugal force are removed. Therefore, it is possible to separate and extract the acceleration component generated due to the velocity change of the true moving object, and to calculate the accurate velocity and moving distance of the moving object. As a result, highly accurate relative position detection using the acceleration sensor can be performed.

Particularly, when the configurations of claims 4 to 6 are added,
Since it is less likely to be mechanically affected by the gravitational acceleration,
Since the error component based on the gravitational acceleration included in the sensor output of the acceleration sensor is suppressed as much as possible, more accurate measurement can be performed by performing the subsequent correction process. Further, in the case of the configuration as in claim 7,
Generally, in accordance with the operating principles described in claims 4 to 6,
Although it is possible to suppress the error component from being included in the sensor output, the attitude control can be stopped when normal operation cannot be performed, such as when the attitude control device may run out of control due to resonance. The error can be removed only by the correction process. Therefore, it is always possible to accurately detect the relative position according to the situation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a navigation device according to the present invention.

FIG. 2 is a block diagram showing a main part thereof.

FIG. 3 is a diagram showing a mounting state of an acceleration sensor and a tilt sensor.

FIG. 4 is a block diagram showing a second embodiment of the navigation device according to the present invention.

FIG. 5 is a block diagram showing a correction device which is a main part thereof.

FIG. 6 is a view showing a mounting state of an acceleration sensor showing a third embodiment of the navigation device according to the present invention.

FIG. 7 is a view showing a mounting state of an acceleration sensor showing a fourth embodiment of the navigation device according to the present invention.

FIG. 8 is a view showing a mounting state of an acceleration sensor showing a fifth embodiment of the navigation device according to the present invention.

FIG. 9 is a view showing a mounting state of an acceleration sensor showing a sixth embodiment of the navigation device according to the present invention.

FIG. 10 is a diagram showing a mounting state of an acceleration sensor showing a seventh embodiment of the navigation device according to the present invention.

FIG. 11 is a view showing an attached state of an acceleration sensor showing an eighth embodiment of the navigation device according to the present invention.

[Explanation of symbols]

 2 GPS device 3 Control device 4 Relative position detection device 6 Display device 7 Gyro sensor 8 Acceleration sensor (for traveling direction) 13 Differentiation processing 14 Integration processing unit 15 Integral function conversion processing unit 15 Inclination sensor 16 Correction table (correction means) 17 Correction Value determiner (correction means) 18 Subtractor (correction means) 25 Centrifugal force direction acceleration sensor 33 Rotation shaft 41, 42 Axis 43 Gimbal structure 45, 46 Damper structure 50 Electromagnetic brake (movement stop mechanism) 51 Electromagnet drive device (movement) Stopping mechanism) 52 Control unit (switching means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Morita 10 No. 10 Hanazono Dodo-cho, Ukyo-ku, Kyoto City, Kyoto Prefecture Omron Co., Ltd. (72) Inventor Atsushi Imakita No. 10 Hanazono Todo-cho, Kyoto City, Kyoto Inside Muron Co., Ltd. (72) Inventor Naoki Fujimoto 10 Todocho, Hanazono, Ukyo-ku, Kyoto City Kyoto Prefecture Inside Omron Corporation

Claims (7)

[Claims] 1. A relative position detecting means for extracting data on a moving direction and a moving amount of a moving object for obtaining a relative position from a reference position, a map information storing means having map information, and a map information storing means for storing the map information and the vehicle. In a navigation device comprising display means for displaying the current position and control means for performing the above control, the relative position detection means includes an acceleration sensor arranged to have high sensitivity in the traveling direction, a gyro sensor, etc. Of the relative position by using an output of the inclination detection device, which has a detection means for detecting information about the traveling direction of the vehicle and is composed of an acceleration sensor arranged so as to have high sensitivity in the direction of gravity. And a correction unit that performs correction for removing an error component based on the inclination included in the sensor output of the acceleration sensor that detects the acceleration in the traveling direction, which is the output of the device. A navigation device characterized in that 2. A relative position detecting means for extracting data on a moving direction and a moving amount of a moving object for obtaining a relative position from a reference position, a map information storing means having map information, and a map information storing means for storing the map information and the vehicle. In a navigation device comprising display means for displaying the current position and control means for performing the above control, the relative position detection means includes an acceleration sensor arranged to have high sensitivity in the traveling direction, a gyro sensor, etc. The acceleration sensor for centrifugal force detection, which has a detecting means for detecting information on the traveling direction of the vehicle and is arranged with high sensitivity in the lateral direction orthogonal to the traveling direction, and the output of the acceleration sensor for detecting the centrifugal force. Correction for removing the error component based on the centrifugal force included in the sensor output of the acceleration sensor that detects the acceleration in the traveling direction, which is the output of the relative position detection device. A navigation device, comprising: 3. An absolute position detecting means for obtaining an absolute position such as GPS is provided, and the control means determines the current position of the vehicle based on output signals from the relative position detecting means and the absolute position detecting means. The navigation device according to claim 1, wherein: 4. The acceleration sensor is attached to the moving object via an attitude control device, and the attitude control device movably supports the acceleration sensor with a predetermined rotation axis or a fulcrum as a reference. ,
The relative attitude of the acceleration sensor with respect to the moving object is controlled so as to change in a direction opposite to a change in the moving attitude of the moving object. Navigation device. 5. The attitude control device comprises a gimbal structure that appropriately rotates about two orthogonal rotation axes, and further has a damper structure in the pitch direction of the moving object. 4. The navigation device according to item 4. 6. The attitude control device comprises a gimbal structure that appropriately rotates about two orthogonal rotation axes, and further has a damper structure in each of a roll direction and a pitch direction of the moving object. The navigation device according to claim 4, which is characterized in that. 7. The attitude control device further comprises a movement stopping mechanism for suppressing the movement of the acceleration sensor, and a mode in which the relative attitude of the acceleration sensor is changed to follow the attitude change of the moving object, The navigation device according to claim 4, further comprising a switching unit that switches a mode for fixing a physical posture.