JP2009293938A - Turn detector, program, and vehicle orientation detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly detect that a vehicle turns during parking without degrading the detection accuracy of an orientation of a vehicle as much as possible. <P>SOLUTION: In a navigation apparatus, the orientation of the vehicle based on a detection result recorded in a RAM before the vehicle is started, the orientation of the vehicle detected by a geomagnetic sensor 22 after the vehicle is stated, and a difference are detected in a positioning process activated when the vehicle is started (S130). If the difference is larger than a preset orientation threshold (S130:YES), it determines that the vehicle turns during parking. It can quickly determine whether the vehicle turns during parking or not. When the vehicle runs, a constitution for detecting the orientation of the vehicle can be employed without utilizing earth magnetism. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a turn detection device, a program, and a vehicle direction detection device having a function of a turn detection device that detects that the vehicle turns while the vehicle is parked.

Conventionally, even in a place where radio waves from GPS satellites cannot be received by transmitting radio waves for position detection from transmitters arranged at three or more places in an underground parking lot or the like, and receiving these radio waves in the vehicle, A navigation device that can detect the position of a vehicle is known (see, for example, Patent Document 1).
JP 2000-310539 A

  By the way, in recent navigation apparatuses, the direction of the vehicle is detected by performing dead reckoning processing using detection results obtained by a GPS receiver, an acceleration sensor, a gyro sensor, or the like. Therefore, even in a place where radio waves from GPS satellites cannot be received, the azimuth and position of the vehicle can be estimated without a large error.

  Here, in a situation where radio waves from GPS satellites cannot be received, turning of the vehicle due to external force occurs during stopping of the vehicle (for example, turning at a turntable in a parking lot or turning due to transportation of a car carrier, car ferry, etc.) Then, since the azimuth before the vehicle stops is adopted as the current azimuth of the vehicle, there is a problem that if the traveling direction cannot be specified based on the radio wave from the GPS satellite, the own vehicle keeps straying on the navigation screen. .

  Even if the radio wave from the GPS satellite cannot be received, the above-described problem can be solved if the radio wave for position detection is received as described in Patent Document 1, but the GPS satellite does not. From the viewpoint of cost, it is not practical to provide equipment that can receive radio waves for position detection at all places where radio waves cannot be received.

  In addition, if the geomagnetic sensor is used, it is possible to detect the direction after the vehicle stops and the above problem may not occur. However, in the configuration using only the geomagnetic sensor, the detection accuracy of the direction of the vehicle is poor and actually When the vehicle is not turning, there is a possibility that the detection accuracy of the direction of the vehicle is deteriorated.

  Therefore, in view of such a problem, it is an object of the present invention to provide means for quickly detecting that the vehicle has been turned during parking without deteriorating the detection accuracy of the vehicle orientation as much as possible. .

  2. The turning detection device according to claim 1, wherein the first difference detecting means is a calculation result recorded in the first recording means before starting the vehicle when the vehicle is started. And the difference between the vehicle orientation and the vehicle orientation based on the detection result acquired by the geomagnetic information acquisition means after the vehicle is started. If the difference detected by the first difference detecting means is greater than a preset first turning threshold, the turning determination means turns the vehicle while the vehicle is parked (the vehicle orientation has been changed). ).

  Here, in general, other methods such as a method of detecting the vehicle direction using the angular velocity and acceleration of the vehicle are more accurate than the method of detecting the vehicle direction using the geomagnetism. It is known that can be detected. However, the other methods mentioned here often employ dead reckoning processing that calculates the latest vehicle direction based on the amount of change from the vehicle direction detected in the past (during the previous operation of the vehicle) Since the calculation by this process stops when the vehicle is parked (when the vehicle is not in operation), it is not possible to detect turning when the vehicle is parked only by this method.

  Therefore, in the turning detection device of the present invention, the turning determination is performed by comparing the azimuth of the vehicle detected by geomagnetism with the azimuth of the vehicle in the past detected by other than geomagnetism.

  According to such a turning detection device, it is possible to quickly determine whether or not the vehicle has turned during parking. In addition, it is possible to employ a configuration in which the azimuth of the vehicle is detected without using geomagnetism while the vehicle is traveling.

In the present invention, since the detection result by the geomagnetism detecting means for detecting the azimuth of the vehicle by geomagnetism is used for comparison, the geomagnetism detecting means may be of relatively low accuracy.
By the way, in the turn detection device according to claim 1, as described in claim 2, the turn determination means is configured such that the difference detected by the first difference detection means is larger than the first turn threshold and the second If the difference detected by the difference detection means is greater than the second turning threshold, it is determined that the vehicle has turned while the vehicle is parked.

  According to such a turning detection device, since the magnetic field before parking is compared with the magnetic field at the time of start-up, the fact that the vehicle has turned due to the fact that the magnetic field is out of order even though the vehicle has not turned is reported. It can be prevented from being detected.

  According to a third aspect of the present invention, there is provided a program for realizing each means constituting the turn detection device according to the first or second aspect as a computer function.

According to such a program, at least the same effect as that of the turn detection device according to claim 1 can be obtained.
Next, in the vehicle orientation detection device according to claim 4, which is configured to achieve the above object, the turning detection means detects that the vehicle has turned while the vehicle is parked, and the vehicle orientation output means includes: At the time of starting the vehicle, when the turning detection means detects that the vehicle has turned, the detection direction based on the detection result acquired by the absolute direction acquisition means is output as the current vehicle direction, and the turning detection means When it is not detected that the vehicle has turned, the backup direction by dead reckoning processing using the detection result by the relative direction acquisition means is output as the current direction of the vehicle.

According to such a vehicle orientation detection device, it is possible to employ a vehicle orientation with higher credibility depending on whether or not the vehicle turns.
Further, in the vehicle orientation detection device according to claim 4, as described in claim 5, the turn detection means may be configured as the turn detection device according to claim 1 or claim 2.

  According to such a turn detection device, in addition to the effect of the vehicle orientation detection device according to claim 4, at least the effect of the turn detection device according to claim 1 can be enjoyed.

Embodiments according to the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a navigation device 1 (turn detection device, vehicle orientation detection device) to which the present invention is applied. The navigation device 1 is a device mounted on a vehicle such as a passenger car, for example, and is configured around a navigation ECU (ECU is an electronic control device) 10.

  In addition to the navigation ECU 10, the navigation device 1 includes a GPS receiver 21, a geomagnetic sensor 22 (geomagnetic detection means), a gyroscope (gyro) 23, an acceleration sensor (G sensor) 24, a vehicle speed sensor 25, An ACC switch 26, a map database (DB) 28, and a display unit 29 are provided.

  The GPS receiver 21, the gyro 23, the G sensor 24, and the vehicle speed sensor 25 correspond to the direction detection means in the present invention. Further, the GPS receiver 21 and the geomagnetic sensor 22 correspond to the absolute direction detection means in the present invention, and the gyro 23, the G sensor 24, and the vehicle speed sensor 25 correspond to the relative direction detection means.

The GPS receiver 21 receives signals from a plurality of GPS satellites and sends them to the navigation ECU 10.
The geomagnetic sensor 22 is a known geomagnetic sensor, and detects the direction of the vehicle by detecting the geomagnetism. The gyro 23 is a known gyroscope, and detects an angular velocity or the like in the vehicle.

  The G sensor 24 is configured as a well-known three-dimensional acceleration sensor, and detects the acceleration applied to the vehicle by decomposing it into three-axis components. The vehicle speed sensor 25 is a well-known vehicle speed sensor and detects the traveling speed of the vehicle.

  Various detection results obtained by the GPS receiver 21, the geomagnetic sensor 22, the gyro 23, the G sensor 24, and the vehicle speed sensor 25 (hereinafter collectively referred to as "various sensors") can be acquired by the navigation ECU 10. Has been.

  The navigation ECU 10 has a function as a well-known microcomputer including a CPU, a ROM, a RAM (first recording means and second recording means), and the like. The navigation ECU 10 acquires detection results from various sensors, and performs processing (including positioning processing described later) based on a program stored in the ROM.

  Specifically, the navigation ECU 10 detects the current position (current location) of the host vehicle based on a signal from the GPS receiver 21. In addition, the navigation ECU 10 repeatedly detects the current position of the host vehicle, thereby detecting the movement vector of the host vehicle (the direction in which the front of the vehicle is facing: the direction of the vehicle).

  Further, the navigation ECU 10 also performs dead reckoning processing for detecting the current position of the vehicle and the traveling direction (the direction in which the front of the vehicle is directed) based on the detection results of the gyro 23, the G sensor 24, and the vehicle speed sensor 25. Then, the navigation ECU 10 reads out map data including the current position of the vehicle from the map DB 28 in which a digital map associated with latitude and longitude is recorded in advance, and uses this map data as a known display together with the current position and traveling direction of the vehicle. It is displayed on the configured display unit 29.

  Moreover, in the navigation apparatus 1 of this embodiment, the process as shown in FIG. 2 is implemented regarding the positioning process which detects the position and direction of the own vehicle. FIG. 2 is a flowchart showing a positioning process performed by the navigation ECU 10.

  In the positioning process, the processes of S120 and S190 correspond to the geomagnetic information acquisition means and the absolute direction acquisition means in the present invention, and the processes of S130 include the first difference detection means, the turn determination means, and the second difference detection means. , And turn detection means. Further, the processes of S140, S150, S170, and S180 correspond to the vehicle direction output means in the present invention.

  Further, the process of S190 also corresponds to a direction information acquisition unit, a second recording control unit, and a relative direction acquisition unit. Further, the processing of S200 and S230 corresponds to the first recording control means.

  The positioning process is a process that starts when an accessory switch (ACC switch) 26 in the vehicle is turned on, and is endlessly executed until the ACC switch 26 is turned off.

  In the positioning process, first, it is detected whether or not the vehicle turns while the vehicle is parked (when the ACC switch 26 is in the OFF state), and the azimuth correction process (FIG. 2) corrects the azimuth of the vehicle according to the detection result. The process indicated by the broken line in FIG. Such azimuth correction processing is performed by a method (relative positioning) that detects the current position of the vehicle by dead reckoning navigation processing that detects the movement locus of the vehicle using the gyro 23, the G sensor 24, the vehicle speed sensor 25, and the like. This is because it is impossible to detect that the vehicle turns while the vehicle is parked.

  As a specific example of the azimuth correction process, as shown in FIG. 2, the current position of the vehicle and the azimuth of the vehicle (backup azimuth: the latest azimuth of past detection results) recorded in the RAM of the navigation ECU 10 are read ( Subsequently, a detection result (geomagnetic direction: current detection result) by the geomagnetic sensor 22 is acquired (S120). Then, it is determined whether or not the difference (absolute value) between the backup orientation and the geomagnetic orientation is larger than a preset orientation threshold (S130).

  Here, the azimuth threshold is set to a value (for example, 90 degrees, 120 degrees, etc.) that is considered to be larger than the magnitude of the error, considering that the detection error by the geomagnetic sensor 22 is relatively large. Just do it. That is, the detection result by the geomagnetic sensor 22 is used to detect whether or not the vehicle has largely turned.

  If the difference between the backup azimuth and the geomagnetic azimuth is less than the azimuth threshold (S130: NO), it is selected that the vehicle is not turning during parking and the backup azimuth is used as the vehicle azimuth (S140), The direction correction process is terminated. If the difference between the backup bearing and the geomagnetic bearing is equal to or greater than the bearing threshold (S130: YES), it is considered that the vehicle has turned around during parking, and it is determined whether or not the next environment can use the GPS satellite. Move. That is, in an environment where GPS satellites can be received and GPS positioning can be performed immediately, the backup orientation is used instead of using the geomagnetic sensor 22 with poor orientation accuracy.

  Specifically, first, the number of captured GPS satellites is detected based on a signal from the GPS receiver 21, and it is determined whether or not the number of captured GPS satellites is equal to or greater than a preset number of satellites threshold (S150). . Here, the satellite number threshold only needs to be set to be equal to or greater than the number of satellites (for example, three) that can detect the current position of the vehicle based on signals from GPS satellites.

  If the number of GPS satellites captured is equal to or greater than the satellite number threshold (S150: YES), it is determined that the GPS receiver 21 can be used, and the use of the backup direction as the vehicle direction is selected (S140). However, in an environment where the GPS receiver 21 can be used, an accurate result is obtained by performing the position / orientation correction in the normal processing of S190 and later, which will be described later, taking into account the detection result of the GPS receiver 21 while taking the backup orientation as a base Calculate the direction of the vehicle. When the process of S140 ends, the azimuth correction process ends.

  On the other hand, if the number of captured GPS satellites is less than the threshold number of satellites (S150: NO), until the GPS receiver 21 is activated and the position of the GPS satellite can be grasped and a signal from the GPS satellite can be used. It is determined whether or not the specified tracking time set to a time slightly longer than the tracking time has elapsed (S170).

  Since the tracking time differs depending on whether or not the navigation device 1 has GPS satellite arrangement data (ephemeris data, almanac data, etc.), the specified tracking time is set to a different time for each navigation device according to the tracking time. Should be.

  If the specified tracking time has elapsed (S170: YES), it is determined that the GPS receiver 21 cannot be used, and the result of detection by the geomagnetic sensor 22 is selected as the vehicle direction (S180), and the direction correction process is performed. finish. If the specified tracking time has not elapsed (S170: NO), it is determined that the availability of the GPS receiver 21 is unknown, and the process returns to S150.

  When such an azimuth correction process is completed, the process from S190 is executed. The processes after S190 are performed in parallel with the azimuth correction process, and when the azimuth correction process is completed, the azimuth of the vehicle may be corrected to the azimuth of the vehicle selected in the azimuth correction process. .

  The processes after S190 are generally well-known positioning processes. First, the detection results of various sensors are recorded in the RAM of the navigation system (Navi ECU 10) (S190). Here, the RAM is configured to be able to record a detection result for a predetermined time (a time required for detecting the vehicle movement vector) set in advance, and the detection result after a predetermined time is stored as needed. The latest detection result is erased by being overwritten.

  Next, a travel locus of the host vehicle is generated based on the detection result recorded in the RAM, and the vehicle orientation that can be detected based on the travel locus is recorded in the RAM together with position information (S200). Subsequently, it is determined whether or not the GPS receiver 21 is available (S210). Whether or not the GPS receiver 21 can be used is determined, for example, by performing the same processing as S150 and S170.

  If the GPS receiver 21 cannot be used (S210: NO), the process returns to S190. If the GPS receiver 21 can be used (S210: YES), the vehicle speed is equal to or higher than a preset specified vehicle speed, or a specified decrease rate with a preset DOP (geometric accuracy reduction rate). It is determined whether or not this is the case (S220).

  The specified vehicle speed and the specified decrease rate are values used as an index for determining whether or not the position and direction need to be corrected. In the processing after S220, when the detection accuracy by the GPS receiver 21 is good, it is determined that the position and direction of the vehicle should be corrected using the detection result by the GPS receiver 21.

  That is, if the vehicle speed is equal to or higher than the specified vehicle speed or DOP is equal to or higher than the specified decrease rate (S220: YES), the detection result by the GPS receiver 21 is also processed as one sensor input signal for dead reckoning processing to correct the position and direction of the vehicle. The position and orientation are recorded in the RAM (S230). In this process, correction is performed using, for example, a well-known Kalman filter.

  When such processing is completed, the processing from S190 is repeated. If the vehicle speed is less than the specified vehicle speed and the DOP is less than the specified decrease rate (S220: NO), the process from S190 is repeated immediately.

  In the navigation device 1 described in detail above, the navigation ECU 10 determines the vehicle orientation based on the detection result recorded in the RAM before starting the vehicle in the positioning process that is started when the vehicle is started, and the vehicle The direction and difference of the vehicle detected by the geomagnetic sensor 22 after starting is detected. And if this difference is larger than the preset azimuth | direction threshold value, it will determine with the said vehicle turning during parking of the said vehicle.

  According to such a navigation apparatus 1, it can be quickly determined whether or not the vehicle has been turned during parking. In addition, it is possible to employ a configuration in which the azimuth of the vehicle is detected without using geomagnetism while the vehicle is traveling. Moreover, since the detection result by the geomagnetic sensor 22 that detects the azimuth of the vehicle by geomagnetism is used for comparison, a sensor with relatively low accuracy can be adopted as the geomagnetic sensor 22.

  Further, the navigation ECU 10 detects that the vehicle has been turned while the vehicle is parked, and if the vehicle has been turned when the vehicle is activated, the navigation ECU 10 displays the detection result by the GPS receiver 21 or the geomagnetic sensor 22. The current direction of the vehicle is output, and when it is not detected that the vehicle has turned, the backup direction is output as the current direction of the vehicle.

According to such a navigation device 1, it is possible to employ a vehicle direction with higher credibility depending on whether the vehicle is turning.
The embodiment of the present invention is not limited to the above-described embodiment, and can take various forms as long as it belongs to the technical scope of the present invention.

  For example, in the above embodiment, in the process of S130, the difference between the backup direction of the detection result by the geomagnetic sensor 22 (the detection result of the geomagnetic sensor 22 in the past) and the geomagnetic direction (the detection result of the geomagnetic sensor 22 at present) is also separately obtained. It is also possible to detect and determine whether or not this difference is greater than or equal to the second orientation threshold. In this case, the difference between the comprehensively detected backup orientation and the geomagnetic orientation is greater than or equal to the orientation threshold, and the difference between the backup orientation and the geomagnetic orientation as a result of detection by the geomagnetic sensor 22 is greater than or equal to the second orientation threshold. If there is, the affirmative determination is made and the difference between the comprehensively detected backup orientation and the geomagnetic orientation is less than the orientation threshold, or the difference between the backup orientation and the geomagnetic orientation as a result of detection by the geomagnetic sensor 22 is the second orientation. If it is less than the threshold value, a negative determination is made.

  According to such a navigation device 1, the magnetic field before parking (before the engine is stopped) and the magnetic field at the time of starting are compared. Therefore, the vehicle is distorted even though the vehicle is not turning. It is possible to prevent the fact that the rotation has been detected.

  In the above embodiment, the configuration in which the geomagnetic sensor 22 is used only when the vehicle is started has been described. However, when the vehicle trajectory is calculated (processing in S200), the detection result by the geomagnetic sensor 22 is used. Also good.

1 is a block diagram showing a schematic configuration of a navigation device 1. FIG. It is a flowchart which shows a positioning process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Navigation apparatus, 10 ... Navigation ECU, 21 ... GPS receiver, 22 ... Geomagnetic sensor, 23 ... Gyro, 24 ... G sensor, 25 ... Vehicle speed sensor, 26 ... ACC switch, 28 ... Map DB, 29 ... Display part.

Claims (5)

A turn detection device that detects that the vehicle has turned while the vehicle is parked,
A geomagnetism information acquisition means for acquiring a detection result by a geomagnetism detection means for detecting the azimuth of the vehicle by detecting the geomagnetism;
Direction information acquisition means for acquiring a detection result by the direction detection means for detecting the direction of the vehicle without detecting geomagnetism,
A first recording control means for recording a calculated orientation by dead reckoning processing using the detection result obtained by the direction information obtaining means in the first recording means;
At the time of starting the vehicle, the vehicle orientation based on the calculated orientation recorded in the first recording means before starting the vehicle and the detection result obtained by the geomagnetic information obtaining means after starting the vehicle. First difference detecting means for detecting the azimuth and the difference;
If the difference detected by the first difference detection means is greater than a preset first turn threshold, a turn determination means for determining that the vehicle has turned while the vehicle is parked,
A turning detection device characterized by comprising: In the turning detection device according to claim 1,
Second recording control means for recording the detection result acquired by the geomagnetic information acquisition means on the second recording means;
At the time of starting the vehicle, the vehicle orientation based on the detection result recorded in the second recording means before starting the vehicle and the detection result acquired by the geomagnetic information acquisition means after starting the vehicle. A second difference detecting means for detecting an azimuth and a difference;
With
The turning determination means is configured such that the difference detected by the first difference detecting means is larger than the first turning threshold, and the difference detected by the second difference detecting means is larger than a preset second turning threshold. If it is larger, it is determined that the vehicle turns while the vehicle is parked.   A program for realizing each means constituting the turn detection device according to claim 1 as a computer function. A vehicle orientation detection device for detecting the orientation of a vehicle,
Absolute azimuth obtaining means for obtaining a detection result by an absolute azimuth detecting means for detecting an absolute azimuth representing an absolute azimuth in the vehicle;
A relative azimuth acquisition means for acquiring a detection result by a relative azimuth detection means for detecting a relative azimuth representing a relative azimuth of the vehicle accompanying the movement of the vehicle;
A turn detection means for detecting that the vehicle has turned while the vehicle is parked;
When the turning detection unit detects that the vehicle has turned at the time of starting the vehicle, the detection direction based on the detection result acquired by the absolute direction acquisition unit is output as the current vehicle direction, and the turning Vehicle orientation output means for outputting, as the current vehicle orientation, the backed up calculated orientation by dead reckoning processing using the detection result by the relative orientation acquisition means when the detection means does not detect that the vehicle has turned. When,
A vehicle orientation detection device comprising: In the vehicle orientation detection device according to claim 4,
The vehicle direction detection device, wherein the turning detection means is configured as the turning detection device according to claim 1 or 2.

Images