Correction device

Abstract

To provide a technique for reducing the influence of rotation by a turntable.SOLUTION: A first processing unit 24 corrects a received voltage value with an offset voltage value. A determination unit 22 determines whether or not a vehicle is rotating based on an image. A second processing unit 25 updates the offset voltage value based on the received voltage value when travel information indicates that the vehicle is stopped and the determination unit 22 determines that the vehicle is not rotating. The second processing unit 25 does not update the offset voltage value when the travel information indicates that the vehicle is stopped and the determination unit 22 determines that the vehicle is rotating.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a correction technique, and more particularly to a correction device for correcting a voltage value output from a gyro sensor.

Background Art

[0002] The positioning of the position and traveling direction of a vehicle is calculated by receiving radio waves from GNSS (Global Navigation Satellite System) satellites or by calculating from detection outputs of angular velocity sensors such as gyro sensors. Since a gyro sensor generates a voltage even when no angular velocity is generated and outputs a voltage value corresponding to the angular velocity generated by being superimposed on the voltage, the voltage value when no angular velocity is generated is stored as an offset voltage value, and the offset voltage value is subtracted from the voltage value output from the gyro sensor. Since the offset voltage value is obtained when the vehicle is stopped, if it fluctuates due to changes in temperature or humidity during running, the accuracy of the traveling direction deteriorates. Therefore, the amount of angular change of the moving body azimuth within a predetermined time is calculated from the output of the gyro sensor and the output of the azimuth detection means respectively, and the offset voltage value of the gyro sensor is updated so that the amount of angular change of both becomes equal (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The gyro sensor checks for the presence or absence of vehicle speed pulses, and when there are no vehicle speed pulses, determines that the vehicle is stopped and updates the offset voltage value. However, when the vehicle is rotating on a turntable, a voltage is generated in the gyro sensor even though the vehicle is stopped, and the offset voltage value is updated based on that voltage value.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide a technique for reducing the influence of rotation by a turntable.

Means for Solving the Problems

[0006] In order to solve the above problems, a correction device according to an aspect of the present invention includes a first input unit that receives a voltage value from a gyro sensor, a first processing unit that corrects the voltage value received by the first input unit with an offset voltage value, a second input unit that receives travel information indicating the travel state of the vehicle, a third input unit that receives an image of the outside of the vehicle, a determination unit that determines whether the vehicle is rotating based on the image received by the third input unit, and a second processing unit that updates the offset voltage value based on the voltage value received by the first input unit when the travel information received by the second input unit indicates that the vehicle has stopped and the determination unit determines that the vehicle is not rotating. The second processing unit does not update the offset voltage value when the travel information received by the second input unit indicates that the vehicle has stopped and the determination unit determines that the vehicle is rotating.

[0007] Another aspect of the present invention is also a correction device. This device includes a first input unit that receives a voltage value from a gyro sensor, a first processing unit that corrects the voltage value received by the first input unit with an offset voltage value, a second input unit that receives travel information indicating the travel state of the vehicle, a third input unit that receives an image of the outside of the vehicle, a determination unit that determines whether a turntable is included in the image received by the third input unit, and a second processing unit that updates the offset voltage value based on the voltage value received by the first input unit when the travel information received by the second input unit indicates that the vehicle has stopped and the determination unit determines that the turntable is not included in the image. The second processing unit does not update the offset voltage value when the determination unit determines that the turntable is included in the image.

[0008] Yet another aspect of the present invention is also a correction device. This device includes a first input unit that receives a voltage value from a gyro sensor, a first processing unit that corrects the voltage value received by the first input unit with an offset voltage value, a second input unit that receives driving information indicating the driving state of the vehicle, a third input unit that receives the position information of the vehicle, a storage unit that stores map information indicating the installation position of the turntable, a determination unit that determines whether the vehicle is in the vicinity of the turntable based on the position information received by the third input unit and the map information stored in the storage unit, and a second processing unit that updates the offset voltage value based on the voltage value received by the first input unit when the driving information received by the second input unit indicates that the vehicle has stopped and the determination unit determines that the vehicle is not in the vicinity of the turntable. The second processing unit does not update the offset voltage value of the voltage value received by the first input unit when the driving information received by the second input unit indicates that the vehicle has stopped and the determination unit determines that the vehicle is in the vicinity of the turntable.

[0009] In addition, any combination of the above components, and those obtained by converting the expression of the present invention among methods, devices, systems, recording media, computer programs, etc., are also effective as aspects of the present invention.

Advantages of the Invention

[0010] According to the present invention, the influence of the rotation by the turntable can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

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Figure 8

Modes for Carrying Out the Invention

[0012] (Embodiment 1) Before specifically describing the present invention, an overview will be first described. This embodiment relates to a correction device that corrects a voltage value output from a gyro sensor mounted on a vehicle or the like with an offset voltage value. In order to reduce the influence of rotation by the turntable, when the correction device determines that the vehicle has stopped based on the vehicle speed pulse, if it analyzes the video imaged by the imaging device and the vehicle is rotating on the turntable, the offset voltage value is not updated. On the other hand, when the correction device determines that the vehicle has stopped based on the vehicle speed pulse, if it analyzes the video imaged by the imaging device and the vehicle is not rotating on the turntable, the offset voltage value is updated.

[0013] FIG. 1 shows the configuration of the correction device 100. The correction device 100 includes a gyro sensor 10, a first input unit 12, a vehicle speed sensor 14, a second input unit 16, an imaging device 18, a third input unit 20, a determination unit 22, a first processing unit 24, a second processing unit 25, a storage unit 26, and an output unit 28. The gyro sensor 10, the vehicle speed sensor 14, and the imaging device 18 may be configured separately from the correction device 100.

[0014] The gyro sensor 10 detects a change in the traveling direction of the vehicle as a relative angular change of the vehicle. That is, the gyro sensor 10 detects the turning angular velocity of the vehicle. The detected angular velocity is output, for example, as an analog signal of 0V to 5V. At that time, a positive angular velocity corresponding to a clockwise turn is output as a deviation voltage from 2.5V to the 5V side, and a negative angular velocity corresponding to a counterclockwise turn is output as a deviation voltage from 2.5V to the 0V side. Also, 2.5V is an offset voltage value and drifts due to influences such as temperature. The voltage value of the gyro sensor 10 is AD (Analog to Digital) converted by an AD conversion device (not shown) at a sampling interval of 100 msec, for example, and the resulting digital signal (hereinafter also referred to as "voltage value") is output to the first input unit 12. The first input unit 12 receives the voltage value from the gyro sensor 10. The first input unit 12 outputs the voltage value to the first processing unit 24.

[0015] The vehicle speed sensor 14 is installed in the middle of a speedometer cable that rotates corresponding to the rotation of the drive shaft, and sequentially outputs vehicle speed pulses accompanying the rotation of the drive shaft to the second input unit 16. That is, the vehicle speed pulses are output for each fixed moving distance as the vehicle moves, and the number of vehicle speed pulses included in a fixed period increases as the vehicle speed increases. The second input unit 16 acquires the vehicle speed pulses from the vehicle speed sensor 14. The vehicle speed pulses correspond to travel information indicating the traveling state of the vehicle. The second input unit 16 outputs the travel information to the determination unit 22 and the second processing unit 25.

[0016] The imaging device 18 is mounted on the front side of the vehicle and can image the outside of the vehicle. The imaging device 18 is, for example, a drive recorder. The imaging device 18 outputs an image of the outside of the vehicle to the third input unit 20. The third input unit 20 receives the image of the outside of the vehicle from the imaging device 18. The third input unit 20 outputs the image to the determination unit 22.

[0017] The determination unit 22 receives the driving information from the second input unit 16 and receives the video from the third input unit 20. When the driving information indicates the vehicle is driving, the determination unit 22 ends the process. When the driving information indicates the vehicle has stopped, the determination unit 22 determines whether the vehicle is rotating by performing image analysis on the video. Known techniques may be used for the image analysis. For example, when the same content is periodically included, it is determined that the vehicle is rotating. The determination unit 22 outputs the determination result to the second processing unit 25. The determination result indicates whether the vehicle is rotating or not.

[0018] The second processing unit 25 receives the driving information from the second input unit 16 and receives the determination result from the determination unit 22. FIG. 2 shows the data structure of the table held in the second processing unit 25. The table shows the correspondence between the driving information, the determination result, and the processing content. When the driving information indicates driving, it is shown that the offset voltage value is not updated as the processing content. When the driving information indicates stopping and the determination result indicates rotation, it is also shown that the offset voltage value is not updated as the processing content. On the other hand, when the driving information indicates stopping and the determination result indicates no rotation, it is shown that the offset voltage value is updated as the processing content. Return to FIG. 1.

[0019] The second processing unit 25 determines the processing content by referring to the table based on the received driving information and determination result. When the driving information indicates the vehicle has stopped and the determination result indicates no rotation, the second processing unit 25 determines to update the offset voltage value based on the voltage value. When the driving information indicates the vehicle has stopped and the determination result indicates rotation, or when the driving information indicates the vehicle is driving, the second processing unit 25 determines not to update the offset voltage value. The second processing unit 25 notifies the first processing unit 24 of the determined content.

[0020] The first processing unit 24 receives a voltage value from the first input unit 12 and also receives a notification from the second processing unit 25. If the notification from the second processing unit 25 indicates an update of the offset voltage value, the first processing unit 24 causes the storage unit 26 to store the received voltage value as the offset voltage value. Further, the first processing unit 24 may calculate an average value of the voltage values over a predetermined period and cause the storage unit 26 to store the average value as the offset voltage value. If the notification from the second processing unit 25 does not indicate an update of the offset voltage value, the first processing unit 24 maintains the offset voltage value stored in the storage unit 26 as it is. Furthermore, the first processing unit 24 corrects the voltage value by subtracting the offset voltage value stored in the storage unit 26 from the voltage value received at the first input unit 12. The output unit 28 outputs the voltage value corrected in the storage unit 26.

[0021] This configuration can be implemented in terms of hardware by a CPU, a memory, and other LSIs of an arbitrary computer, and can be implemented in terms of software by a program loaded into the memory or the like. Here, however, functional blocks realized by the cooperation thereof are depicted. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

[0022] The operation of the correction device 100 having the above configuration will be described. FIG. 3 is a flowchart showing an update procedure by the correction device 100. When the vehicle is running (Y in S10), the first processing unit 24 and the second processing unit 25 do not update the offset voltage value (S14). When the vehicle is not running (N in S10), if the vehicle is rotating (Y in S12), the first processing unit 24 and the second processing unit 25 do not update the offset voltage value (S14). When the vehicle is not rotating (N in S12), the first processing unit 24 and the second processing unit 25 update the offset voltage value (S16).

[0023] According to this embodiment, after determining whether the vehicle is rotating based on the video, when the vehicle stops and is not rotating, the offset voltage value is updated, so the influence of rotation by the turntable can be reduced. Also, after determining whether the vehicle is rotating based on the video, when the vehicle stops and is rotating, the offset voltage value is not updated, so the influence of rotation by the turntable can be reduced.

[0024] (Embodiment 2) Next, Embodiment 2 will be described. Similar to Embodiment 1, Embodiment 2 also relates to a correction device that corrects the voltage value output from a gyro sensor mounted on a vehicle or the like with an offset voltage value. In the correction device according to Embodiment 2, the process of determining whether the vehicle is rotating on the turntable is different from that in Embodiment 1. The correction device 100 according to Embodiment 2 is of the same type as shown in FIG. 1. Here, the description will focus on the differences from Embodiment 1.

[0025] The determination unit 22 in FIG. 1 receives the driving information from the second input unit 16 and the video from the third input unit 20. When the driving information indicates that the vehicle is driving, the determination unit 22 ends the process. When the driving information indicates that the vehicle has stopped, the determination unit 22 determines whether the turntable is included in the video by performing image analysis on the video. Any known technique may be used for the image analysis. For example, an image of the turntable is stored in advance as a reference image, and pattern matching is performed between the video and the reference image. The determination unit 22 outputs the determination result to the second processing unit 25. The determination result indicates whether the turntable is included. Here, the turntable being included may mean that the turntable is included in the front-rear direction of the vehicle.

[0026] The second processing unit 25 receives the running information from the second input unit 16 and receives the determination result from the determination unit 22. FIG. 4 shows the data structure of the table held in the second processing unit 25. The table shows the correspondence relationship among the running information, the determination result, and the processing content. When the running information indicates running, it is shown that the offset voltage value is not updated as the processing content. When the determination result indicates that the bogie is included, it is shown that the offset voltage value is not updated as the processing content. On the other hand, when the running information indicates stop and does not include the bogie, it is shown that the offset voltage value is updated as the processing content. Return to FIG. 1.

[0027] The second processing unit 25 determines the processing content by referring to the table based on the received running information and determination result. When the running information indicates the stop of the vehicle and the determination result does not include the bogie, the second processing unit 25 determines to update the offset voltage value based on the voltage value. When the determination result indicates that the bogie is included, or when the running information indicates the running of the vehicle, the second processing unit 25 determines not to update the offset voltage value.

[0028] The operation of the correction device 100 with the above configuration will be described. FIG. 5 is a flowchart showing the update procedure by the correction device 100. When the bogie is included (Y in S50), the first processing unit 24 and the second processing unit 25 do not update the offset voltage value (S54). When the bogie is not included (N in S50), and when the vehicle is running (Y in S52), the first processing unit 24 and the second processing unit 25 do not update the offset voltage value (S54). When the vehicle is not running (N in S52), the first processing unit 24 and the second processing unit 25 update the offset voltage value (S56).

[0029] According to this embodiment, when the bogie is not included in the video, if the vehicle stops, the offset voltage value is updated, so the influence of the rotation of the bogie can be reduced. Also, after determining whether the vehicle is rotating based on the video, when the vehicle including the bogie in the video is rotating, the offset voltage value is not updated, so the influence of the rotation of the bogie can be reduced.

[0030] (Example 3) Next, Example 3 will be described. Similar to the previous examples, Example 3 also relates to a correction device that corrects the voltage value output from a gyro sensor mounted on a vehicle or the like using an offset voltage value. In the correction device according to Example 3, the process of determining whether the vehicle is rotating while on a turntable is different from the previous ones. Here, the explanation will focus on the differences from the previous ones.

[0031] FIG. 6 shows the configuration of the correction device 100. The correction device 100 includes a gyro sensor 10, a first input unit 12, a vehicle speed sensor 14, a second input unit 16, a third input unit 20, a determination unit 22, a first processing unit 24, a second processing unit 25, a storage unit 26, an output unit 28, a positioning device 30, and a storage unit 32. The gyro sensor 10, the vehicle speed sensor 14, the positioning device 30, and the storage unit 32 may be configured separately from the correction device 100.

[0032] The positioning device 30 receives signals from GNSS satellites (not shown) and calculates positioning data as a positioning result. Therefore, the positioning data includes position information, GNSS speed which is the moving speed, GNSS azimuth which is the azimuth of the vehicle, PDOP (Position Dilution Precision), the number of captured satellites, etc. Here, the position information is indicated by latitude and longitude. PDOP is an index of how the error in the GNSS satellite position in the positioning data is reflected in the receiving point position and corresponds to the positioning error. Note that the positioning data may include values other than these. Also, since the calculation of the positioning data may be performed by a known technique, the explanation is omitted here. The positioning device 30 outputs the positioning data to the third input unit 20. The third input unit 20 receives the vehicle's position information by receiving the positioning data from the positioning device 30. The third input unit 20 outputs the vehicle's position information and the like to the determination unit 22. The storage unit 32 stores map information. The map information shows the installation position of the turntable.

[0033] The determination unit 22 receives the driving information from the second input unit 16 and the position information from the third input unit 20. Also, the determination unit 22 can refer to the map information stored in the storage unit 32. When the driving information indicates the vehicle is driving, the determination unit 22 ends the process. When the driving information indicates the vehicle has stopped, the determination unit 22 determines whether the vehicle is in the vicinity of the turntable based on the vehicle's position information and the map information. For example, when the vehicle's position information is included in the range within a radius of 10 m from the installation position of the turntable shown in the map information, the determination unit 22 determines that the vehicle is in the vicinity of the turntable. The determination unit 22 outputs the determination result to the second processing unit 25. The determination result indicates whether there is a turntable or not.

[0034] The second processing unit 25 receives the driving information from the second input unit 16 and the determination result from the determination unit 22. FIG. 7 shows the data structure of the table held in the second processing unit 25. The table shows the correspondence relationship among the driving information, the determination result, and the processing content. When the driving information indicates driving, it is shown that the offset voltage value is not updated as the processing content. When the driving information indicates a stop and the determination result indicates that there is a turntable, it is also shown that the offset voltage value is not updated as the processing content. On the other hand, when the driving information indicates a stop and the determination result indicates that there is no turntable, it is shown that the offset voltage value is updated as the processing content. Return to FIG. 1.

[0035] The second processing unit 25 determines the processing content by referring to the table based on the received driving information and the determination result. When the driving information indicates that the vehicle has stopped and the determination result indicates that there is no turntable, the second processing unit 25 determines to update the offset voltage value based on the voltage value. When the driving information indicates that the vehicle has stopped and the determination result indicates that there is a turntable, or when the driving information indicates that the vehicle is driving, the second processing unit 25 determines not to update the offset voltage value.

[0036] The operation of the correction device 100 configured as described above will be described. FIG. 8 is a flowchart showing the update procedure by the correction device 100. When the vehicle is running (Y in S100), the first processing unit 24 and the second processing unit 25 do not update the offset voltage value (S104). When the vehicle is not running (N in S100), if there is a bogie (Y in S102), the first processing unit 24 and the second processing unit 25 do not update the offset voltage value (S104). When there is no bogie (N in S102), the first processing unit 24 and the second processing unit 25 update the offset voltage value (S106).

[0037] According to the present embodiment, after determining whether the vehicle is present in the vicinity of the bogie, when the vehicle stops and is not present in the vicinity of the bogie, the offset voltage value is updated, so that the influence of the rotation by the bogie can be reduced. Further, after determining whether the vehicle is present in the vicinity of the bogie, when the vehicle stops and is present in the vicinity of the bogie, the offset voltage value is not updated, so that the influence of the rotation by the bogie can be reduced.

[0038] As described above, the present invention has been described based on the embodiments. These embodiments are illustrative, and it is understood by those skilled in the art that various modifications are possible for each of the constituent elements and combinations of the processing processes, and such modifications are also within the scope of the present invention.

[0039] Any combination of Embodiments 1 to 3 is also possible. According to this modification example, the influence of the rotation by the bogie can be reduced.

Explanation of Reference Numerals

[0040] 10 Gyro sensor, 12 First input unit, 14 Vehicle speed sensor, 16 Second input unit, 18 Imaging device, 20 Third input unit, 22 Determination unit, 24 First processing unit, 25 Second processing unit, 26 Storage unit, 28 Output unit, 100 Correction device.

Claims

1. A first input unit that receives a voltage value from a gyro sensor; A first processing unit that corrects the voltage value received by the first input unit with an offset voltage value; A second input unit that receives travel information indicating the travel state of the vehicle; A third input unit that receives an image of the outside of the vehicle; A determination unit that determines whether or not the vehicle is rotating based on the image received by the third input unit; A second processing unit that updates the offset voltage value based on the voltage value received by the first input unit when the determination unit determines that the travel information received by the second input unit indicates that the vehicle has stopped and the vehicle is not rotating; and The second processing unit is a correction device that does not update the offset voltage value when the determination unit determines that the travel information received by the second input unit indicates that the vehicle has stopped and the vehicle is rotating.

2. A first input unit that receives a voltage value from a gyro sensor; A first processing unit that corrects the voltage value received by the first input unit with an offset voltage value; A second input unit that receives travel information indicating the travel state of the vehicle; A third input unit that receives an image of the outside of the vehicle; A determination unit that determines whether or not a turntable is included in the image received by the third input unit; A second processing unit that updates the offset voltage value based on the voltage value received by the first input unit when the determination unit determines that the travel information received by the second input unit indicates that the vehicle has stopped and the turntable is not included in the image; and The second processing unit is a correction device that does not update the offset voltage value when the determination unit determines that the turntable is included in the image.

3. A first input unit that receives a voltage value from a gyro sensor; A first processing unit that corrects the voltage value received by the first input unit with an offset voltage value; A second input unit that receives travel information indicating the travel state of the vehicle; A third input unit that receives the position information of the vehicle; A storage unit that stores map information indicating the installation position of the turntable; A determination unit that determines whether or not the vehicle is present in the vicinity of the turntable based on the position information received by the third input unit and the map information stored in the storage unit; When the determination unit determines that the travel information received by the second input unit indicates a stop of the vehicle and the vehicle is not in the vicinity of the turntable, a second processing unit that updates the offset voltage value based on the voltage value received by the first input unit is provided. The second processing unit is a correction device that does not update the offset voltage value of the voltage value received by the first input unit when the determination unit determines that the travel information received by the second input unit indicates a stop of the vehicle and the vehicle is in the vicinity of the turntable.

Images