JP2008122252A - Device of correcting signal of angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device of correcting a signal of an angular velocity sensor by which precise correction processing is allowed. <P>SOLUTION: An angular velocity value ω1 obtained from a gyroscope is corrected on the basis of curvature information input from a map data input part about a road on which a vehicle currently travels and the vehicle velocity information of the vehicle calculated by a vehicle velocity sensor or the like (steps T1 to T9). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a signal correction device that corrects a signal of an angular velocity sensor mounted on a moving body.

  Since the angular velocity sensor is accompanied by a change in the output signal due to temperature drift or the like, a signal correction device for correcting this kind of error is required. This type of signal correction apparatus is disclosed in Patent Documents 1 to 3, for example.

  For example, according to the offset drift correction device described in Patent Document 1, it is determined whether or not the moving body is in a turning motion, the angular velocity from the gyro sensor is smoothed, and the smoothed average angular velocity is used for adaptation. Specifically, the offset level of the gyro sensor is estimated, and the offset level of the gyro sensor is subtracted from the angular velocity output from the gyro sensor as needed to cancel the offset of the gyro sensor.

  Further, for example, according to the gyro drift correction method and correction circuit described in Patent Document 2, digital data is obtained from the output signal from the gyro sensor at regular intervals, and the first moving average value within a predetermined time is obtained from the digital data. The vehicle direction data obtained by the map matching process is obtained every fixed time, the difference value is obtained, the second moving average value within a predetermined time is obtained based on the difference value, and the first movement The difference between the average value and the second moving average value is obtained as a drift correction value, and the difference between the digital data and the drift correction value is calculated to obtain corrected gyro data.

Further, for example, according to the moving body position speed calculation device described in Patent Document 3, the estimation error means uses the absolute position, the absolute speed, the absolute inclination angle, the road direction and the absolute position as observation values, and the error of the inertial navigation sensor data and the inertial navigation. The error of attitude, speed, and position, which is the output of the means, is corrected.
Japanese Patent Laid-Open No. 7-324941 JP-A-8-114455 JP-A-9-189564

  For example, even if the technique disclosed in Patent Document 1 is applied, if the correction process is performed under a situation where the vehicle turns slowly, the signal of the angular velocity sensor output by the actual turn changes due to temperature drift or the like. As a result, the correction process is mistakenly performed.

  In this case, the technique disclosed in Patent Document 2 uses the road direction obtained as a result of the map matching process for the correction process, but there is a difference between the direction of the matched road and the actual vehicle direction. If correction processing is performed in some cases (for example, during lane change or meandering operation), erroneous correction occurs.

  In addition, even when the technique disclosed in Patent Document 3 is applied, if the received signal from the GPS satellite is used to obtain the absolute position and the road direction, the GPS depends on the surrounding environment such as the satellite position and the shielding object. An error occurs in the positioning result, and even if correction processing is performed, erroneous correction occurs.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a signal correction device for an angular velocity sensor that enables accurate correction processing.

  According to the first aspect of the present invention, the correction unit corrects the signal value of the angular velocity sensor based on the curvature information of the road derived from the road information input to the map information input unit and the moving speed of the moving body. Compared to calculating road curvature information from information acquired from GPS satellites, etc., it is possible to obtain more accurate road curvature information and accurately correct the signal value of the angular velocity sensor. It can be carried out.

  According to the invention described in claim 2, the determination unit determines whether or not the moving body is moving along a road that satisfies the condition that the curvature information is within a predetermined range, and the road that satisfies the condition. Since the correction process is performed only when moving along the line, more accurate correction process can be performed.

  According to the invention of claim 3, the lane marking recognition unit recognizes a lane marking in the road from the captured image, and the determination unit is on the road on the condition that it exists within a predetermined image range in the captured image. Whether or not the moving body is moving along the road in order to determine that the moving body is not moving along the road on the condition that the moving body is moving along the road. Can be determined more accurately, and more accurate correction processing can be performed.

  According to invention of Claim 4, a presence determination part magnetically determines whether a magnetic marker exists in the predetermined range of a road, and if a presence determination part exists in a predetermined range of a road, If it determines, a determination part will determine with the moving body moving along the road. In addition, when the determination unit determines that the magnetic marker does not exist within the predetermined range of the road, the determination unit determines that the moving object is not moving along the road, so the moving object moves along the road. It is possible to more accurately determine whether or not the correction is performed, and more accurate correction processing can be performed.

  According to the fifth aspect of the present invention, the curvature information of the road is accurately calculated because the calculation unit calculates the curvature information of the road based on the position information of the plurality of nodes in the road input to the map information input unit. Thus, accurate correction processing can be performed.

  According to the sixth aspect of the present invention, the position information of a plurality of nodes and the curvature information of the road between adjacent nodes are input in advance to the map information input unit, so there is no need to calculate the curvature information of the road. Accurate curvature information can be acquired. Thereby, more accurate correction processing can be performed.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is applied to a vehicle navigation device will be described with reference to FIGS. 1 to 4.

  FIG. 1 schematically shows an electrical configuration of a vehicle navigation apparatus by a combination of functional blocks. As shown in FIG. 1, a vehicle navigation apparatus 1 includes a control circuit 2, and a position detector 3, a map data input unit 4, a display device 5, an operation switch group 6, A voice input / output circuit 7, a remote control sensor 8, a storage device 9, a voice recognition device 10, a camera 11, a transceiver 12 and the like are connected.

  The control circuit 2 includes a CPU (not shown), a memory 2a, and the like, and functions as a correction unit, a determination unit, a lane marking recognition unit, and a presence / absence determination unit. Among the components of the control circuit 2, a memory program is stored in the memory 2a. In addition to the program, processing data at the time of program execution, road map data (road information) acquired from the map data input unit 4, and the like Is temporarily stored.

  The position detector 3 includes, for example, a GPS receiver 13 that receives a GPS signal from a GPS (Global Positioning System) artificial satellite, a gyroscope (angular velocity sensor) 14 for detecting a yaw rate (angular velocity), and a relative position of the vehicle. A vehicle speed sensor 15 for detecting the speed is provided.

  The position detector 3 includes an acceleration sensor for detecting acceleration in three axial directions orthogonal to each other and an inclination sensor for detecting an inclination angle in the pitching direction of the vehicle according to the detection accuracy and the like. It may be applied in place of a part of the constituent elements, or may be added. The position detector 3 detects the position with high accuracy while interpolating the detection signals of these components. Further, the control circuit 2 can always calculate the traveling direction of the vehicle by using the position detection elements 13 to 15.

  The map data input unit 4 is a device for inputting map data (map information) using a large-capacity information storage medium such as a CD-ROM, DVD-ROM, hard disk, or nonvolatile semiconductor memory. . This map data includes map drawing data for map display, road data necessary for various processes such as map matching, route search, route guidance, intersection data consisting of detailed intersection data, and background layers. In addition to place name data for displaying points such as background data, place names, areas, etc., facility name data in which facility names are arranged in the order of, for example, Japanese syllabary, telephone number data indicating correspondence between telephone numbers and facilities, expressways, etc. The data corresponding to the map such as the service area, the parking area, the point data of the parking lot, etc. are targeted.

  These map data are recorded for each of the data described above and are stored in a database. The road data (road information) includes information such as position coordinates of road nodes such as latitude and longitude and road curvature information between the plurality of nodes. This road curvature information is information on the curvature of roads throughout the country that has been measured in advance by various measuring devices.

  Various road data including such curvature information is stored in an information storage medium such as the above-mentioned CD-ROM, DVD-ROM, hard disk, or nonvolatile semiconductor memory, and the map data input unit 4 stores each road data. Corresponding accurate curvature information is input.

  The display device 5 is configured by, for example, a color liquid crystal display for displaying a map screen or the like, and is installed in the vicinity of the driver's seat of the vehicle. On the screen of the display device 5, a road map whose scale can be changed in a plurality of stages in normal times is displayed, and a pointer indicating the current position and traveling direction of the vehicle is displayed so as to overlap the display. It has become.

  The calculation for setting the optimum route to the destination is performed by a known Dijkstra method or the like. At this time, when the route guidance function performed based on the route calculation result to the destination is executed, the guidance route to be traveled in a state of being superimposed on the road map is displayed on the screen of the display device 5. In addition, various menu screens and input screens for searching for a destination such as a destination or waypoint by a user (generally a vehicle driver) and inputting these points, and various messages, information and help screens are also displayed. It is like that.

  The operation switch group 6 includes a mechanical switch disposed around the display device 5 and a touch panel formed on the display screen of the display device 5, and commands related to operations such as various data and setting items. It is provided to give to the control circuit 2.

  The voice input / output circuit 7 includes a voice synthesis circuit and the like, and is connected to a speaker 16 and a microphone 17. The voice input / output circuit 7 generates a voice output corresponding to voice information from the control circuit 2 and outputs the voice output to the speaker 16. It is configured to input voice information from. The remote control sensor 8 receives an operation signal from the remote control 18 and gives it to the control circuit 2.

  The camera 11 is installed in the vehicle and functions as an imaging unit that captures a peripheral image in the vehicle traveling direction (vehicle traveling direction) when the vehicle is stopped or while the vehicle is traveling, and transmits the imaging information to the control circuit 2. It is configured.

  The transceiver 12 is a transceiver of VICS (Vehicle Information And Communication System) information, for example, and is configured to perform communication processing with the infrastructure data transceiver 19 installed outside the vehicle.

  Based on the command input through the operation switch group 6 or the remote control sensor 8, the control circuit 2 uses a well-known map display function, route calculation function, route guidance function, telephone number search function, postal code search function, map code (registration). Process related to a wide variety of support functions such as a search function using a unique code such as a trademark, a 50 sound search function, a genre search function, a nearest facility search function, a destination registration function, a point registration function, etc. It is configured.

The operation of the above configuration will be described with reference to FIGS.
2 and 4 schematically show the correction processing performed by the control circuit using a flowchart.

  As shown in FIG. 2, the control circuit 2 acquires captured image information by the camera 11 (step S1), and determines whether or not it can be determined whether or not the vehicle is traveling along a road (step S2). . Specifically, the control circuit 2 determines whether or not a white line (partition line) drawn in advance in the road exists in the captured image information while acquiring the vehicle speed pulse from the vehicle speed sensor 15. Judgment is made based on the recognition technique, and when the white line is present within the predetermined range in the captured image information, it is determined that the determination process is possible. If the condition is not satisfied, the determination process is disabled. If the determination process is disabled (step S2: NO), the process returns to step S1.

  If the determination process is permitted, the control circuit 2 determines whether or not the vehicle is traveling along a certain vehicle lane (predetermined lane: corresponding to a road) (step S3). FIG. 3A and FIG. 3B schematically show this determination process. FIG. 3A shows an example of a case where it is determined that the vehicle is traveling along the road, and FIG. 3B is a case where it is determined that the vehicle is not traveling along the road (change in course: lane change). An example of the case is shown.

  When the vehicle is traveling in the travel lane S1, an image A1 shown in FIG. As shown in FIG. 3A, in the image A1, a white line W1 drawn on the shoulder of the road surface R and a white line W2 drawn between the adjacent vehicle lanes S1 and S2 are shown. A white line W2 indicates a lane marking that divides the traveling lane S1 and the overtaking lane S2 on the road surface R. The control circuit 2 detects a detection line D1 corresponding to the white line W1 and a detection line D2 corresponding to the white line W2 in the image A1 by using an image recognition technique.

  The control circuit 2 divides the image A1 into a plurality of regions (two left and right image regions divided by the center line C in the example shown in FIG. 3), and determines in which partition region the detection lines D1 and D2 exist respectively. To do. At this time, the control circuit 2 determines that the vehicle is traveling along the travel lane S1 by determining that the detection lines D1 and D2 are each within a certain predetermined area range in the image A1. . In the example shown in FIG. 3A, the detection line D1 exists in the image area on the left side of the center line C, and the detection line D2 exists in the image area on the right side of the center line C. Therefore, along the traveling lane S1. It is determined that the vehicle is running.

  When the vehicle changes its course (lane change), the camera 11 usually captures an image as shown in FIG. When the vehicle changes its course, the vehicle straddles the white line W2 on the center side of the road surface R. Then, since the white lines W1 and W2 in the captured image A1 relatively move, the detection lines D1 and D2 also move so as to follow.

  For example, in the example shown in FIG. 3B, when the vehicle is traveling on the driving lane S1, the detection line D1 exists in the left area of the center line C, and the detection line D2 exists in the right area of the center line C. However, when the vehicle changes its course from the travel lane S1 to the overtaking lane S2, the detection line D2 is detected so as to straddle the center line C.

  For this reason, the control circuit 2 determines that the detection line D2 has deviated from the range of the predetermined partition region, and determines that the vehicle is not traveling along a predetermined vehicle lane (road). In this way, it is determined in step S3 whether or not the vehicle is traveling along the road. As shown in FIG. 2, the control circuit 2 performs angular velocity correction processing on the condition that the vehicle is traveling along the road (step S3: YES) (step S4).

  FIG. 4 schematically shows an angular velocity correction process performed by the control circuit. As shown in FIG. 4, the control circuit 2 calculates an angular velocity value ω1 based on the output signal of the gyroscope 14 (step T1). Since the output signal of the gyroscope 14 is accompanied by changes over time such as temperature drift, correction processing is performed by performing the following steps T2 to T9.

  The control circuit 2 acquires absolute position information and azimuth information from the GPS signal received by the GPS receiver 13 (step T2). Next, relative distance information is acquired based on integrating the vehicle speed pulses acquired from the vehicle speed sensor 15 (step T3).

  Next, the control circuit 2 obtains a relative trajectory by inertial navigation from the angular velocity value ω1, the relative distance information, the absolute position information, and the azimuth information acquired in the above step, and calculates traveling speed information (step T4). Next, a map matching process is performed on the road information input from the map data input unit 4 (step T5), and any of the nodes in the road data input to the map data input unit 4 by a traveling vehicle is detected. To be located on the road.

Next, the curvature information of the road for which the vehicle is specified after the map matching is acquired from the map data input unit 4 (step T6). Since accurate curvature information corresponding to each road is input to the map data input unit 4, the control circuit 2 can acquire accurate curvature information of the identified road. Next, the angular velocity ω2 is estimated from the acquired curvature information of the road and the traveling speed information. When the traveling speed value is v [m / s] and the curvature value is 1 / r [m-1],
ω2 = v / r (1)
Therefore, the angular velocity value ω2 can be estimated from this information. The angular velocity value ω2 thus obtained and the angular velocity value ω1 calculated based on the output signal of the gyroscope 14 are compared to calculate a correction value ω1-ω2 (step T8), and correction processing (calibration) is performed. Do.

  Although the angular velocity value ω1 that can be obtained from the gyroscope 14 due to temperature drift or the like is not an accurate value, an accurate angular velocity value can be obtained by performing such correction processing.

  According to this embodiment, the control circuit 2 is based on the curvature information input from the map data input unit for the road on which the vehicle is currently traveling, and the vehicle speed information calculated by the vehicle speed sensor 15 and the like. Since the angular velocity value ω1 of the gyroscope 14 is corrected, accurate correction processing can be performed and a correct angular velocity value can be obtained.

  Further, the control circuit 2 determines whether or not the vehicle is traveling along the traveling lane S1, and performs correction processing on the condition that the vehicle is traveling along the traveling lane S1, so that the control circuit 2 changes the course of the vehicle. Correction processing can be performed without being adversely affected by fluctuations in the output signal of the gyroscope 14, and more accurate correction processing can be performed.

  In addition, the control circuit 2 recognizes the white lines W1 and W2 as detection lines D1 and D2 in the captured image by performing image processing of the captured image captured by the camera 11, and detects these detection lines D1 and D2. Are located within the partitioned area range across the center line C in the image A1, and it is determined that the vehicle is traveling along the traveling lane S1, and the detection lines D1 and D2 are defined as the partitioned area range. Since it is determined that the vehicle is not traveling along the driving lane S1 on the condition that the vehicle has deviated from the vehicle, it is possible to more accurately determine whether the vehicle is traveling along the road, and more accurate correction. Processing can be performed.

  In addition, since the position information (latitude and longitude) of a plurality of road nodes and the curvature information of the road between adjacent nodes are respectively input to the map data input unit 4, it is possible to accurately calculate the road curvature information without having to calculate the road curvature information. Curvature information can be acquired, and accurate correction processing can be performed.

(Second Embodiment)
FIG. 5 shows a second embodiment of the present invention. The difference from the previous embodiment is that the control circuit calculates the curvature information of the road between the nodes. The same parts as those of the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts will be described below.

FIG. 5 schematically shows a method for estimating the radius of curvature.
In FIG. 5, road nodes N <b> 1 to N <b> 4 indicate nodes input from the map data input unit 4. The direction when the nodes N1 and N2 are linearly coupled is D0, the direction when the nodes N2 and N3 are linearly coupled is D1, the direction when the nodes N3 and N4 are linearly coupled is D2, and the nodes N1 and N2 Assuming that the position of the vehicle between is P1, and the position of the vehicle between nodes N3 and N4 separated by a distance L from the position P1 is P2, the radius of curvature r [m] between the positions P1 and P2 is given by the following equation: r = L / | D2-D0 | (2)
The curvature information can be obtained as 1 / r [m ⁻¹ ].

  Therefore, if the control circuit 2 as the calculation unit can calculate the curvature information of the road based on the position information of a plurality of nodes and derive the curvature information from the position information of the road node by applying the equation (2), The curvature information can be accurately calculated, can be applied to the correction processing described in the above-described embodiment, and substantially the same effects as those in the above-described embodiment can be obtained.

(Other embodiments)
The present invention is not limited to the above embodiment, and for example, the following modifications or expansions are possible.
Although applied to the navigation apparatus 1 for vehicles in the said embodiment, you may apply to other mobile body mounting uses.
Although applied to the white line as the road lane marking, it may be applied to the lane markings of other colors (yellow).

  In the above embodiment, the imaging information obtained by the camera 11 is acquired in step S1, and it is determined whether or not the vehicle is traveling along the road based on the imaging information in step S2. When the vehicle is moving along the road on the condition that the magnetic marker installed on the vehicle is magnetically confirmed by a magnetic sensor and determined to be within a predetermined range of the road. It may be determined. In this case, substantially the same effect as the white line detection process in the above embodiment is obtained.

  In the above embodiment, the angular velocity correction process is performed on the condition that it is determined that the vehicle is traveling along the road, but step S2 for determining whether or not the vehicle is traveling along the road. And the determination process of S3 should just be provided as needed.

  In the above embodiment, absolute position information and azimuth information are acquired in step T2, vehicle speed pulses are acquired in step T3, relative distance information is acquired, travel speed information is calculated in step T4, and step T5 is executed. The road division is input and the curvature information is acquired in step T6, but all or some of these information acquisition processes may be performed in step S1.

1 is a block diagram schematically showing an electrical configuration according to a first embodiment of the present invention. Flow chart schematically showing the operation Explanatory drawing of the judgment process of whether it is driving along the road Flow chart schematically showing angular velocity correction processing Explanatory drawing of the curvature information calculation method of the road in the 2nd Embodiment of this invention

Explanation of symbols

  In the drawings, 1 is a navigation device (signal correction device for angular velocity sensor), 2 is a control circuit (correction unit, determination unit, lane marking recognition unit, existence determination unit), 4 is a map data input device (map information input unit), Reference numeral 11 denotes a camera (imaging unit).

Claims (7)

  Angular velocity characterized by comprising a correction unit for correcting the signal value of the angular velocity sensor based on the curvature information of the road derived from the road information input from the map information input unit and the moving speed of the moving body Sensor signal correction device. A determination unit that determines whether or not the moving object is moving along a road that satisfies the condition that the curvature information is within a predetermined range;
The signal correcting device for an angular velocity sensor according to claim 1, wherein the correction unit corrects the signal on the condition that the determination unit determines that the vehicle is moving along a road. A lane marking recognition unit that recognizes a lane marking in the road from a captured image captured by an imaging unit that images a road;
The determination unit determines that the moving body is moving along the road on the condition that the lane line recognized by the lane line recognition unit exists within a predetermined image range in the captured image. The signal correcting device for an angular velocity sensor according to claim 2, wherein it is determined that the moving body is not moving along the road on the condition that the image is out of the predetermined image range. A presence / absence determination unit that magnetically determines whether or not the magnetic marker exists within a predetermined range of the road,
The determination unit determines that the moving body is moving along the road on the condition that the presence / absence determination unit determines that the magnetic marker is within a predetermined range of the road, and the magnetic marker is 4. The angular velocity sensor according to claim 2, wherein it is determined that the moving body is not moving along the road on the condition that the presence / absence determination unit determines that the vehicle does not exist within a predetermined range of the road. Signal correction device. In the map information input unit, position information of a plurality of nodes in the road is input,
5. The signal correcting device for an angular velocity sensor according to claim 1, further comprising a calculating unit that calculates road curvature information based on information of the plurality of nodes. 6.   The position information of a plurality of nodes in the road is input to the map information input unit, and curvature information of the road between adjacent nodes among the plurality of nodes is input. 6. A signal correction device for an angular velocity sensor according to any one of 1 to 5.   The angular velocity sensor signal correction apparatus according to claim 1, wherein the moving body is a vehicle.

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