JP5545663B2 - Gyro zero point correction method and apparatus - Google Patents

Description

  In the gyro used for detecting the traveling direction of the host vehicle of the navigation device, for example, the angular velocity detection characteristic changes depending on the temperature or the like. Therefore, when appropriately correcting the zero point, the angular velocity of the gyro when the vehicle is stopped is averaged. More particularly, the present invention relates to a gyro zero point correction method capable of dealing with rotation by a turntable when a vehicle is stopped, and an apparatus for implementing the method.

  For example, in a navigation device mounted on a vehicle, the current position of the vehicle is accurately detected, a map corresponding to the current position is displayed on the monitor, and the current position is overlaid on the map to display the current position on the map. Displaying the position is a basic function. In addition, it has a function of calculating a guidance route from the current location to the destination and performing guidance for safely guiding the vehicle to the destination according to the guidance route. Therefore, it is extremely important to display at which point on the map the current position is in the navigation device.

  A current position detection method using a GPS system is widely used as a method for detecting the current position of a vehicle, and can detect an almost accurate position when satellite positioning is properly performed. When entering a tunnel, in the shadow of a building, or in the mountains, accurate positioning may not be performed or it may not function at all.

  Therefore, in addition to satellite navigation using GPS as described above, vehicle speed pulses used for vehicle speed detection, mileage calculation, etc., and a gyro that is currently chipped and provided at low cost are used. A self-contained navigation method is also used in which the angular velocity of the vehicle is detected and the moving distance and moving direction from the position as the base point are detected.

  The gyros used at this time are various chip gyros widely used in camera shake correction, device posture detection such as mobile phones and personal digital assistants, game device posture detection, and robot posture detection. Although most of them can be used, the output characteristics gradually change from the initial use state, such as a change in characteristics due to temperature, to the subsequent use.

  Therefore, it is preferable that these gyroscopes appropriately correct the zero point during use, and conventionally, a zero point correction technique has been proposed. In a navigation gyro mounted on a vehicle, it is preferable to perform zero point correction as frequently as possible, particularly because the temperature of the gyro changes drastically due to changes in the surrounding environment due to traveling of the vehicle and the high temperature of the engine room.

  In the gyro zero point correction in such a vehicle-mounted navigation device, the gyro output is detected when the vehicle is stopped, and the output at that time is assumed to be the zero point output. Thereafter, a signal is output assuming that the value obtained by subtracting the zero point correction value from the gyro output is an accurate value.

  For example, as shown in FIG. 4A, when the standard value of the gyro output value is 2.5 V, the vehicle is detected by detecting that the gyro output is stable for a predetermined period between time t1 and time t2. It is determined that the vehicle has stopped, and the difference between the gyro output value and the standard value at that time is set as the zero point correction value. Thereafter, as shown by the thick broken line in the figure, the zero point correction value is the value at t2 when stopping is determined. Set to a value and keep this value thereafter. In the example of FIG. 4A, the stop determination is performed again between the times t3 and t4, thereby maintaining the zero point correction value at the time t4 as the subsequent zero point correction value.

  In the example of FIG. 4A, when obtaining the zero point correction value based on the gyro output when the vehicle is stopped as described above, if the gyro output is greater than or equal to the predetermined range, the value is not adopted as unreliable. Therefore, an example is shown in which an upper limit threshold value of + A and a lower limit threshold value of -A are set for the standard value of 2.5V.

  By setting such an upper limit threshold and a lower limit threshold, for example, an operation as shown in FIG. That is, the output value of the gyro at time t2 is set as the zero point correction value because the output is stable within the upper limit threshold between time t1 and t2, as in FIG. At the time of the next gyro output stabilization between t3 and t4, since the lower limit threshold 2.5-A was exceeded, the value is not adopted as being unreliable, and the zero point correction value is maintained as the previous value. .

  In many cases, the stop of the vehicle at this time can be detected by detecting a vehicle speed pulse for detecting the travel distance of the vehicle, the rotation speed of the tire, or the travel speed. There are many vehicles that detect vehicle speed and the like without using them, and many retrofit navigation devices purchased on the market do not detect vehicle speed pulses. Even when a vehicle speed pulse is detected, the output signal may become unstable when the vehicle speed is very low because the vehicle speed pulse is used in an anti-skid or anti-lock brake system. Some of them are not output.

  Therefore, in the navigation device mounted on the vehicle, the fact that the vehicle is stopped is based on the fact that the output of the gyro is essentially zero, and by the output of the gyro as described above, the output of the gyro is, for example, for 3 seconds, It has been proposed to determine that the vehicle is stopped when the average value is within the threshold and continues for a predetermined time, and to determine that the vehicle has started running when the average exceeds the threshold. In the example shown in FIG. 4 as well, such processing is performed during the stoppage determination period. At this time, in addition to using the output value of the gyro when the stop determination is made as described above as the zero point correction value, the output value of the gyro is determined to be zero immediately before or just after it is determined that the vehicle has started running. It has also been proposed to adopt a point correction value (Patent Document 1).

  However, this technique has a problem that an erroneous zero point correction value is taken in at a low speed of the vehicle. That is, in a vehicle using a vehicle speed sensor with a dead zone in the low speed range, the vehicle speed sensor does not generate a vehicle speed pulse when traveling at a low speed of about 1 to 2 km / h. Read the signal and calculate the zero point correction value. For this reason, since the gyro sensor measures the direction of the host vehicle using the wrong zero point correction value when the vehicle travels thereafter, it cannot perform accurate direction measurement.

 In addition, when the turntable with the vehicle rotates smoothly in a parking lot with a turntable, the gyro output stabilizes at a constant angular velocity for at least several seconds, so it is determined that the vehicle is stopped and the gyro output at this time is output. It is taken in as a zero point correction value, the wrong zero point correction value is calculated, and then the correct orientation cannot be measured.

  Regarding the gyro zero point correction problem when turning on such a turntable, the turning of the vehicle is accurately detected by an absolute direction sensor using a magnetic sensor, and such erroneous zero point correction is performed. It is disclosed in Patent Document 2 that it is not performed. However, this technique requires the use of a separate magnetic sensor, which must be expensive.

  Further, as a method for detecting that the vehicle is rotating on a turntable without using a magnetic sensor as described above, an upper limit and a lower limit of the standard value of the gyro output as in the example shown in FIG. By using a technology to set the threshold value, and setting the range of the threshold value to a value slightly smaller than the output value of the gyro when rotating on the turntable, the zero point correction value is set when the threshold value is exceeded. It is proposed by the present applicant in Patent Document 3 that the problem is solved by an unsought technique.

  According to this technique, for example, the process shown in FIG. In other words, when the vehicle rotates on the turntable from time t1 to time t2, a value slightly smaller than the value output by the gyro at the rotational angular velocity of the turntable is set as the threshold value. Similarly to b), since the output value at that time is not adopted as the zero point correction value, the value when rotating on the turntable is not adopted as the zero point correction value. The figure shows an example in which a stop determination is subsequently made between times t3 and t4, and since the output value of the gyro at that time is within the threshold range, a new zero point correction value is obtained thereafter. .

JP-A-5-52578 JP-A-5-157572 JP 2008-32591 A

  As described above, the gyro in the navigation device used in the vehicle sets the upper and lower thresholds to the standard value of the output of the gyro when calculating the zero point correction value when the vehicle is stopped, and gets on the turntable when exceeding it. It has been proposed that the zero point correction value is not calculated as a rotating object.

  However, when this technique was further studied, it was found that there was a problem as shown in FIG. That is, in the same figure, the output of the gyro is stabilized from time t1, and the stop determination is made by stabilizing for a predetermined period until time t2. Since the output of the gyro at this time exceeds the threshold for performing the turntable determination, the output of the gyro at this time is not adopted as the zero point correction value and is regarded as being on the turntable. As a result, the zero point correction value indicated by the bold broken line in the figure remains at the start of stopping.

  In the example of FIG. 5 (b), unlike the example of FIG. 5 (a), the gyro output has stably exceeded the threshold value, and has continued to exceed the upper threshold value, at least exceeding the threshold value. Since the value at that time is not adopted as the zero point correction value, the zero point correction value is maintained as it is without changing from when the vehicle stopped.

  In such a state, since the zero point correction value of the gyro remains the standard value in the illustrated example, this gyro exceeds the threshold value than the standard value and is the same as when rotating on the turntable. Since a relatively large output is produced, the vehicle position mark in the vehicle navigation device continues to rotate in the same manner as in the state of rotating on the turntable.

  In such a case, when the vehicle subsequently departs, it departs from a state in which it is facing a completely different direction at the current position, and therefore moves in the wrong direction on the map as the vehicle travels. For this reason, when the vehicle position is matched to a nearby road by map matching, a display indicating that the vehicle is traveling in the wrong direction on a completely different road is displayed.

  Thereafter, the vehicle further travels, and it can be seen from the travel pattern and the like that the road with its own vehicle position mark is different from the road on which the vehicle is actually traveling. In that case, since the wrong information is continuously provided to the user for a while from the departure, the reliability of the navigation device is lost.

  In addition, if the threshold value is widened in order to solve the above-mentioned problem, it is impossible to detect that the vehicle is rotating on the turntable. If the range is maintained, the gyro used here needs to be able to operate stably within this threshold range. Therefore, further improvement in the performance of the gyro is required, or it is necessary to select a high-performance gyro among the various gyros currently provided. If it is not possible to improve the performance of such gyros, it will be necessary to select the gyros manufactured in the gyro manufacturing stage in a more severe range from the manufactured gyros. It must be a thing. Such a problem occurs not only in the navigation apparatus but also in a gyro when detecting the angular velocity of the vehicle in various control of the vehicle.

  Therefore, according to the present invention, when the zero point correction value of the gyro output is obtained by the gyro output signal at the time of stopping, the gyro threshold is set so that the gyro output when rotating on the turntable is not the zero point correction value. When setting, it is possible to calculate zero point correction data in a gyro that outputs an output exceeding the threshold even when it is not on the turntable, and there is no need for a high-performance gyro, and a direction mark when the vehicle stops The main purpose is to solve the problem of continuous rotation.

  In order to solve the above problem, the gyro zero point correction method according to the present invention determines the gyro zero point correction value based on the output of the gyro that detects the current direction of the vehicle when it is determined that the vehicle is stopped. In the gyro zero-point correction method to be calculated, a threshold value is set above and below the standard output value of the gyro at least within a range within the output of the gyro when the vehicle is rotating on the turntable, and the vehicle stops. The elapsed time when the output of the gyro when it is detected is outside the range of the threshold is detected and the elapsed time exceeding the threshold is calculated, and the elapsed time does not exceed the predetermined time. When the output of the gyro falls within the threshold range, it is determined that the vehicle is rotating on the turntable, and when the predetermined time is exceeded, the vehicle It determines that were not riding Bull, when it is determined that not riding on the turntable, and sets the zero point correction value after the zero-point correction value when starting the vehicle stop determination of the vehicle.

  Further, another gyro zero point correction method according to the present invention is the gyro zero point correction method, wherein the determination that the vehicle is stopped is performed when the output of the gyro is within a predetermined range for a predetermined time. It is determined that the vehicle has stopped.

  Another gyro zero point correction method according to the present invention is characterized in that, in the gyro zero point correction method, the determination that the vehicle is stopped is performed by detecting a vehicle speed pulse. And

  Further, another gyro zero point correction method according to the present invention is characterized in that, in the gyro zero point correction method, the gyro zero point correction value is calculated from data of an average value of a gyro output. .

  Further, another gyro zero point correction method according to the present invention is the gyro zero point correction method according to the present invention, wherein the setting of the gyro zero point correction value starts the stop determination stored in the gyro output zero point correction value storage means. The zero point correction value at the time is taken in and set as the zero point correction value.

  Further, according to another gyro zero point correction method according to the present invention, in the gyro zero point correction method, when the gyro zero point correction value is set, it is determined that the vehicle is rotating on a turntable. The zero point correction value before the stop determination is set.

  Another gyro zero point correction method according to the present invention is the gyro zero point correction method according to the present invention, wherein when setting the gyro zero point correction value, the gyro output exceeds the set threshold value after the stop determination is made. If not, the zero point correction value at the time of stoppage determination is set as the subsequent zero point correction value.

  Another gyro zero point correction method according to the present invention is the gyro zero point correction method according to the present invention, wherein when setting the gyro zero point correction value, the gyro output exceeds the set threshold value after the stop determination is made. When the vehicle starts to travel after that, the zero point correction value before the predetermined time when the start of traveling is detected is set as the zero point correction value after the start of traveling.

  In addition, another gyro zero point correction method according to the present invention is the gyro zero point correction method according to the present invention, wherein when the gyro zero point correction value is set, it is determined that the vehicle is rotating on a turntable. Then, when the vehicle starts traveling, a zero point correction value before a predetermined time when the start of traveling is detected is set as a zero point correction value after the start of traveling.

  Another gyro zero point correction method according to the present invention is characterized in that, in the gyro zero point correction method, the gyro zero point correction device is applied to a gyro output of a navigation device.

Further, the gyro zero point correction device according to the present invention is a gyro for detecting the current traveling direction of the vehicle, a stop determination unit for determining that the vehicle has stopped,
A gyro zero having a gyro zero point correction value calculating unit for calculating a zero point correction value for correcting the zero point of the gyro by the output of the gyro when the stop determination unit detects that the vehicle is stopped. In the point correction apparatus, a gyro output threshold setting unit that sets a threshold within a range within at least a gyro output when the vehicle is rotating on a turntable above and below the standard output value of the gyro, and the vehicle stop Elapsed time when the output of the gyro when it is detected by the determination means that the vehicle is stopped is outside the threshold range set by the gyro output threshold setting means and has continuously exceeded the threshold. The elapsed time calculated after the gyro output threshold exceeding the time for calculating the time and the elapsed time calculated by the elapsed time calculating means after the gyro output threshold exceeded are a predetermined time. When the gyro output is within the threshold range without exceeding, it is determined that the vehicle was rotating on the turntable, and when the predetermined time was exceeded, the vehicle was not on the turntable. When it is determined that the turntable upper rotation determination means and the turntable upper rotation determination means are not on the turntable, the zero point correction value when the vehicle stop determination is started by the stop determination means And a gyro zero point correction value setting means for setting as a zero point correction value.

  Further, another gyro zero point correcting apparatus according to the present invention is the gyro zero point correcting apparatus, wherein the stop determination unit is configured such that the vehicle stops when the output of the gyro is within a predetermined range for a predetermined time. It is characterized by determining.

  Another gyro zero point correction apparatus according to the present invention is characterized in that, in the gyro zero point correction apparatus, the stop determination means detects and detects a vehicle speed pulse.

  Further, another gyro zero point correction apparatus according to the present invention is characterized in that, in the gyro zero point correction apparatus, the gyro zero point correction value calculating means calculates the average value data of the gyro output. .

  Another gyro zero point correction apparatus according to the present invention is a gyro output zero point correction value storage that stores the zero point correction value calculated by the gyro zero point correction value calculation means in the gyro zero point correction apparatus. And the gyro zero point correction value setting means takes in the zero point correction value at the start of stop determination stored in the gyro output zero point correction value storage means and sets it as a zero point correction value. .

  According to another aspect of the present invention, there is provided a gyro zero point correction device, wherein the gyro zero point correction value setting unit includes a turn table on-rotation determination unit, and the vehicle rides on the turn table. When it is determined that the vehicle is rotating, the zero point correction value before the stop determination is performed by the stop determination unit is set.

  The gyro zero point correction device according to the present invention is the gyro zero point correction device, wherein the gyro zero point correction value setting means determines the stop by the stop determination means, and then the gyro output is the gyro output. When the threshold value is not exceeded, the zero point correction value at the time of stopping determination is set as the subsequent zero point correction value.

  The gyro zero point correction device according to the present invention is the gyro zero point correction device, wherein the gyro zero point correction value setting means determines the stop by the stop determination means, and then the gyro output is the gyro output. When the threshold value is not exceeded and the vehicle starts to travel thereafter, a zero point correction value before a predetermined time when the start of traveling is detected is set as a subsequent zero point correction value.

  According to another aspect of the present invention, there is provided a gyro zero point correction device, wherein the gyro zero point correction value setting unit includes a turn table on-rotation determination unit, and the vehicle rides on the turn table. When the vehicle starts running after it is determined that it is rotating, the zero point correction value before a predetermined time when the start of running is detected is set as the zero point correction value after the start of running. To do.

  Another gyro zero point correction apparatus according to the present invention is characterized in that, in the gyro zero point correction apparatus, the gyro zero point correction apparatus is applied to a gyro output of a navigation apparatus.

  Since the present invention is configured as described above, when the zero point correction value of the gyro output is obtained from the gyro output signal when the vehicle is stopped, the gyro output when rotating on the turntable is not set as the zero point correction value. In this way, when setting the threshold value of the gyro output, it is possible to calculate zero point correction data in a gyro that outputs an output exceeding the threshold value even when it is not on the turntable, and there is no need for a high-performance gyro. Further, it is possible to solve the problem that the bearing mark continues to rotate when the vehicle is stopped.

It is a functional block diagram of the Example of this invention. It is an operation | movement flowchart of the Example. It is a figure explaining the action | operation of the Example. It is explanatory drawing of a prior art example. It is explanatory drawing of another prior art example.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of an embodiment of a gyro zero point correction apparatus according to the present invention, and shows a functional block diagram in which the present invention can be implemented in various modes. In addition, in the same figure, the function part which performs each function can be said to be a means which performs each function.

  In the embodiment shown in FIG. 1, the stop determination unit 1 detects that the vehicle has stopped, and this is detected by a vehicle speed pulse 2 that is output to detect the vehicle speed and travel distance. In addition, it can be detected by the gyro output 3 proposed conventionally.

  At that time, the data of the gyro output detection unit 4 is directly used to detect that the output is stable for a predetermined time, or an average value is calculated based on the gyro output value as described later, and the value continues for a predetermined time. It is possible to make a stop determination using the gyro output, such as determining that the vehicle has stopped. Accordingly, it is possible to determine whether the vehicle has stopped, for a vehicle that does not generate a vehicle speed pulse, a vehicle that outputs a vehicle speed pulse, a vehicle that does not generate a vehicle speed pulse, or the like.

  The data detected by the gyro output detection unit 4 is also output to the gyro output average value calculation unit 5 as described above. For example, an average value for 3 seconds is obtained and the average value is calculated by a method such as calculating this every 1 second. calculate. As a result, even a relatively large signal vertically output from the gyro every moment can be detected relatively stably and the current gyro output value can be detected almost accurately. 4 and 5 and FIG. 3 described as an embodiment of the present invention, such average value data is used as the gyro output value.

  The data of the gyro output average value calculation unit 5 is used by the stop determination unit 1 as described above, and as a zero point correction value 12 at the start of stop determination in the stop gyro zero point correction value storage unit 10 as described later. In the illustrated example, it is further stored in the gyro zero point correction value calculation storage unit 13 after stoppage determination, and can be easily applied when using zero point correction values at various times in various embodiments of the present invention. Yes.

  The data of the gyro output average value calculation unit 5 is further output to the gyro output threshold setting unit 14 so that it can be used for setting an appropriate threshold according to the gyro output at that time. Furthermore, it outputs to the gyro output threshold value excess detection part 6, and is used also for the detection of whether the gyro output as mentioned later exceeded the threshold value.

  In the gyro output threshold value excess detection unit 6, as described above, the gyro output average value, which is the basic data for which the gyro output average value calculation unit 5 performs zero point correction, is outside the threshold value range set by the gyro output threshold value setting unit 14. That is, whether or not the threshold value is exceeded. In the detection of exceeding the gyro output threshold value used at this time, in addition to the average value calculated by the gyro output average value calculation unit 5, the gyro output data itself detected by the gyro output detection unit 4 is used to cope with such an output value. Based on the threshold value, it may be detected whether the threshold value is exceeded.

  In the turntable upper rotation determination unit 7, an elapsed time after exceeding the threshold detected by the later-described gyro output threshold excess elapsed time calculation unit 15 is detected by the gyro output threshold excess detection unit 5. When a signal that falls within the threshold value is input from the gyro output threshold value excess detection unit 6 before a predetermined time such as elapses, it is determined that the vehicle is rotating on the turntable.

  On the other hand, when it is detected that the elapsed time calculated by the elapsed time calculation unit 15 exceeding the gyro output threshold exceeds a predetermined time such as 1 minute, the output of the gyro exceeds the threshold on the turntable. It is determined not to be due to riding and rotating but to exceed the threshold due to temperature drift of the gyro.

  In the turntable upper rotation determination unit 8 in the turntable upper rotation determination unit 7, in the process of determining whether or not the turntable upper rotation determination unit 7 finally rotates on the turntable, When it is detected by the output threshold value excess detection unit 6 that the threshold value is exceeded, it is temporarily determined that the vehicle is rotating on the turntable.

  In this temporary determination, the elapsed time calculation unit 15 after the gravel output threshold value exceeded is detected by the signal from the gyro output threshold value excess detection unit 6 to be within the threshold value before a predetermined time such as 1 minute elapses. At the time, it is finally determined that it was rotating on the actual turntable. On the other hand, when it is detected that the vehicle has rotated for a predetermined time or more, the provisional determination is canceled and it is determined that the vehicle is not on the turntable.

  As will be described later, the gyro zero point correction value output unit 9 applies the gyro zero point correction value set by the gyro zero point correction value setting unit 16 to the output of the gyro during the subsequent vehicle running, Corresponding to the changing vehicle environment, appropriate zero point correction is performed to obtain an accurate bearing signal.

  In the stopping gyro zero point correction value storage unit 10, the gyro used before stopping when the stop determination unit 1 determines that the vehicle has stopped with the zero point correction value 11 before starting the stop determination. The zero point correction value is stored. The zero point correction value stored here is taken in by the stationary zero point correction value fetching unit 17 in the gyro zero point correction value setting unit 16 and an appropriate zero point correction value is not obtained when the vehicle is stopped. In addition, it is used to use the previous value as it is.

  Moreover, the value of the zero point correction value 12 at the start of stop determination stores the zero point correction value at the start of the determination process when the stop determination unit 1 performs the stop determination process as described above. The zero point correction value stored here is also zero when the stop zero point correction value capturing unit 17 determines that the vehicle is not rotating on the turntable, particularly by the turntable rotation determination unit 7. The point correction value is read and set as the subsequent zero point correction value.

  The post-stop determination gyro zero point correction value calculation storage unit 13 calculates and stores a gyro zero point correction value based on the gyro output average value when the vehicle stops calculated by the gyro output average value calculation unit 5. In the gyro zero point correction value setting unit 16, the zero point correction value at the time of stopping is set to a value other than the zero point correction value before the stop determination start or the zero point correction value at the start of the stop determination as described above. When using the present invention in various modes, such as using the zero point correction value immediately before the start of vehicle travel, take in the gyro zero point correction value after stopping determination stored here and perform the desired operation To be able to.

The gyro output threshold value setting unit 14 sets the upper and lower limits of the gyro output based on the average value of the gyro output after the stop calculated by the gyro output average value calculation unit 5 as described above, or using a preset threshold value. Set the threshold. The threshold value at this time is 4 [deg.], Assuming that the angular velocity during rotation is constant, for example, when the vehicle rotates on a turntable and rotates 20 degrees in 5 seconds, for example. / s]. Therefore, the rotating gyro output value Vgyro0 is as follows when the zero point voltage of this gyro is 2.5 V and the voltage angular velocity conversion coefficient (K) is 40 (deg / s) / V.
Vgyro0 = 2.5 [V] +4 [deg / s] / 40 [(deg / s) / V] = 2.6 [V]
From now on, the threshold A can be set to 100 mV in consideration of clockwise and counterclockwise.

  The gyro output threshold excess elapsed time calculation unit 15 calculates the elapsed time after the gyro output threshold excess detection unit 6 detects that the gyro output exceeds the threshold as described above. Based on the elapsed time data, the turntable rotation determination unit 7 determines whether the turntable is rotating on the turntable.

  The gyro zero point correction value setting unit 16 also uses the determination result of the turntable upper rotation determination unit 7 as described above, and the stop time gyro zero point correction value storage unit 10 and the post-stop determination gyro zero point correction value calculation storage unit. 13 data is fetched, one of the data is set as a gyro zero point correction value in a preset manner, and is output to the gyro zero point correction value output unit 9.

  In particular, the stopping zero point correction value capturing unit 17 stores either data of the zero point correction value 11 before stopping determination or the zero point correction value 12 when starting stopping determination in the stopping gyro zero point correction value storage unit 10. Capture.

  In that case, if it is determined that the output on the turntable 7 is not on the turntable and is rotating, for example, if there is an output exceeding the threshold value due to temperature drift or the like, the zero point at the start of stoppage determination The correction value 11 is captured. On the other hand, when it is determined that the vehicle is rotating on the turntable, the zero point correction value 12 before starting the stop determination is captured.

  In the present invention consisting of functional blocks as shown in FIG. 1, for example, it can be carried out by sequentially operating according to the operation flow shown in FIG. In the example of the gyro zero point correction value setting process when the vehicle is stopped in FIG. 2, the first stop is detected (step S <b> 1).

  The stop determination at this time can be determined by the gyro output 3 as already described in the description of the stop determination unit 1 in FIG. 1, and these can be determined as shown in the prior art of FIG. As shown in the example 3 of the present invention, after the stop determination is started from time t1, it can be determined that the vehicle is stopped when the gyro output is stable until a predetermined time t2. However, it is not always necessary to use the gyro output data for the stop determination, and when the vehicle speed pulse can be used for accurate stop determination, the stop determination can be performed accordingly.

  In the example of FIG. 2, thereafter, the zero point correction values of the gyro before and at the start of the stop determination are stored (step S2). This processing is stored as a zero point correction value 11 before starting the stop determination and a zero point correction value 12 when starting the stop determination in the stop time gyro zero point correction value storage unit 10 of FIG. These stored values are then read and used in steps S9, S11, and S12 described later.

  Next, the average value of the gyro output is calculated at predetermined time intervals, and updated and recorded as a zero point correction value. In this process, the average value calculation unit 5 in FIG. 1 uses the detection data of the gyro output detection unit 4 to calculate, for example, an average value every 3 seconds for the gyro output detected every second, and this average The post-stop determination gyro zero point correction value calculation storage unit 13 calculates and stores the zero point correction value based on the value data. In the present invention, this processing is not necessarily essential, but in the present invention, various modes such as using a zero point correction value before a predetermined time at the start of vehicle travel are used in selecting the zero point correction value after stoppage determination. Going for when using in.

  Thereafter, it is determined whether or not the average value of the gyro output is within a threshold value (step S4). The threshold value at this time is a threshold value set by the gyro output threshold value setting unit 14 of FIG. 1, and in the example obtained by the calculation formula, an example of setting it to 100 mV is shown. Therefore, in the example shown in FIG. 3, when the standard value of the gyro output is 2.5 V, the threshold A is ± 100 m.

  When it is determined in step S4 that the average value of the gyro output is within the threshold value, the process proceeds to step S12 in the example of FIG. 2, and is updated to the gyro zero point correction value at the time of stoppage determination, and this process ends. (Step S13). That is, in this example, when the average value of the gyro output is within the threshold range when the vehicle is stopped, the zero point correction value when the stop determination is performed as the update processing of the zero point correction value of the steady gyro output. Adopted.

  When it is determined in step S4 that the average value of the gyro output is not within the threshold value, that is, outside the threshold value range, the process proceeds to step S5, where it is temporarily determined that the gyro output is rotating on the turntable (step S4). S5). This process is performed by the turntable temporary rotation determination unit 8 in the turntable rotation determination unit 7 of FIG.

  Thereafter, an elapsed time after the average value of the gyro output exceeds the threshold value is detected (step S6). Next, it is determined whether or not the average value of the gyro output is within the threshold before a predetermined time such as one minute has passed after the threshold is exceeded (step S7). As a result, when it is determined that the average value of the gyro output is within the threshold value before a predetermined time such as one minute has passed after the threshold value is exceeded, the process proceeds to step S10, and the average value of the gyroscope exceeds the threshold value. This is because it was because it was rotating on the turntable.

  That is, as described in the description of the turntable rotation determination unit 7 in FIG. 1, when the turntable rotates 20 degrees in 5 seconds from the standpoint of the standard operation of the turntable, the turntable usually faces the multistory parking lot. The vehicle that has been moving forward is often used to turn 180 degrees so that it can move forward from the multilevel parking lot, so it takes 45 seconds to rotate 180 degrees, so the safety factor is anticipated. With a normal turntable, it should stop after 60 seconds, that is, 1 minute.

  For this reason, when it is determined in step S7 that the average value of the gyro output is within the threshold before a predetermined time such as one minute has passed after the threshold is exceeded, it is determined that the vehicle is on the turntable. Therefore, the determination as described above is performed in step S10.

  After the determination is made in step S10, the zero point correction value of the gyro is kept the value before the stop determination start. In other words, when it is determined that the vehicle is rotating on the turntable as described above, the gyro output at that time cannot be used as the zero point correction value. To do.

  In this process, when the gyro zero point correction value setting unit 16 shown in FIG. 1 determines that the turntable rotation determination unit 7 is rotating on the turntable, the stationary zero point correction value capturing unit 17 is stopped. However, it is performed by taking in the data of the zero point correction value 11 before the stoppage determination start of the stop time gyro zero point correction value storage unit 10.

  In the example shown in FIG. 2, in order to clearly show the main point of the present invention, the operation mode of the zero point correction of the gyro output is shown in a simplified manner, and therefore the average value of the gyro output exceeds the threshold value in step S7. When it is determined that the time is within the threshold before the predetermined time has elapsed, an example is shown in which the gyro zero point correction value is immediately left at the value before the stop determination start in step S11. In practice, various zero point correction values may be set according to various operation modes of the vehicle, such as performing zero point correction based on an average value of the gyro output during the subsequent stoppage of the vehicle.

  At that time, as described in Patent Document 3, the zero point correction value a predetermined time before the start of traveling is set as the subsequent zero point correction value, and at a low speed at the start of traveling. It can also handle large handle operations. As described above, in the present invention, the zero point correction can be performed by applying various conventional techniques other than those shown in the drawings. The zero point correction value updating process in step S12 and the zero point correction in step S9 described later are performed. The same applies to the value acquisition process.

  If it is determined in step S7 that the average value of the gyro output has not returned within the threshold before the predetermined time has elapsed after the threshold has been exceeded, the process proceeds to step S8, and the vehicle is rotating on the turntable. The temporary determination in step S5 is canceled, and it is determined that the threshold value has been exceeded due to temperature drift of the gyro and the like.

  Thereafter, the zero point correction value of the gyro at the start of stoppage determination is taken in, and a series of processing is finished (step S13). That is, when it is determined that the vehicle is not on the turntable, the gyro output has actually exceeded the threshold due to temperature drift or the like, and such a gyro output is similarly generated in the subsequent gyro output. Even a value exceeding the threshold value is used as the zero point correction value, and the stop point determination start zero point correction value 12 of FIG. 1 is taken in and used as the subsequent zero point correction value.

  With the above-described processing, for example, as shown in FIG. 3 (a), a stop determination is made between times t1 and t2, and when the gyro output at that time exceeds the threshold, the time for which the threshold has been exceeded is predetermined. When one minute of time has passed, the previous zero point correction value was adopted until time t1, whereas the zero point correction value was determined by the value of time t1 which is the gyro output at the start of stoppage determination. This is used as the zero point correction value thereafter.

  By performing such processing, the average value of the gyro output exceeding the threshold value can be used as the zero point correction value while performing the turntable determination, and even a relatively poor performance gyro having a large output variation is sufficient. It can be used and it can be set as an inexpensive apparatus. In addition, since the zero point correction as described above is performed even when the gyro output exceeds the threshold value, a mark indicating the azimuth is obtained by not adopting the zero point correction value for the output exceeding the threshold value as in the past. The problem of continuing the same rotation as on the turntable can also be solved.

  Although the present invention can be effectively used for the navigation device mounted on the vehicle as described above, it can be similarly applied to other portable navigation devices brought into the vehicle, and other than the navigation device. In addition, the present invention can be effectively used for a gyro that detects the angular velocity of the vehicle in various vehicle controls such as vehicle attitude control.

DESCRIPTION OF SYMBOLS 1 Stop determination part 2 Vehicle speed pulse 3 Gyro output 4 Gyro output detection part 5 Gyro output average value calculation part 6 Gyro output threshold value excess detection part 7 Turntable upper rotation determination part 8 Turntable upper rotation temporary determination part 9 Gyro zero point correction value Output unit 10 Stoppage gyro zero point correction value storage unit 11 Stoppage determination start zero point correction value 12 Stoppage determination start zero point correction value 13 Stoppage determination gyro zero point correction value calculation storage unit 14 Gyro output threshold setting unit 15 Gyro output Elapsed time calculation unit 16 exceeding threshold value Gyro zero point correction value setting unit 17 Stop point zero value correction value capturing unit

Claims (20)

In the gyro zero point correction method for calculating a zero point correction value of the gyro by the output of the gyro that detects the current direction of the vehicle when it is determined that the vehicle is stopped.
Above and below the standard output value of the gyro, set a threshold value within a range within the output of the gyro when the vehicle is rotating on a turntable,
Calculating the elapsed time when the output of the gyro when detecting that the vehicle is stopped is outside the range of the threshold, and continuously exceeding the threshold,
When the elapsed time does not exceed the predetermined time and the gyro output falls within the threshold range, it is determined that the vehicle has been rotated on the turntable, and when the predetermined time is exceeded, the vehicle Determined that he was not on the turntable,
A gyro zero point correction method, characterized in that, when it is determined that the vehicle is not on the turntable, a zero point correction value when the vehicle stoppage determination is started is set as a subsequent zero point correction value. 2. The gyro zero point correction method according to claim 1, wherein the determination that the vehicle is stopped determines that the vehicle has stopped when the output of the gyro is within a certain range for a predetermined time. 2. The gyro zero point correcting method according to claim 1, wherein the determination that the vehicle is stopped is performed by detecting a vehicle speed pulse of the vehicle. In the calculation of the zero point correction value of the gyro, the zero point compensation method for gyro according to claim 1, wherein the calculating the data of the average value of the gyro output. 2. The zero point correction value at the time of stopping determination stored in the gyro output zero point correction value storage means is taken in and set as a zero point correction value when setting the zero point correction value of the gyro. The gyro zero point correction method described. The zero point correction value of the gyro is set to a zero point correction value before the stop determination is made when it is determined that the vehicle is rotating on the turntable. Zero point correction method for gyro. When setting the zero point correction value of the gyro , if the average value of the gyro output does not exceed the set threshold after the stop determination, the zero point correction value at the stop determination is set as the subsequent zero point correction value. The gyro zero point correcting method according to claim 1, wherein: When setting the zero point correction value of the gyro , when the gyro output does not exceed the set threshold after determining the stop, and when the vehicle starts to travel after that, a predetermined time before the start of traveling is detected. 2. The gyro zero point correction method according to claim 1, wherein the zero point correction value is set as a zero point correction value after the start of traveling. When setting the zero point correction value of the gyro , after determining that the vehicle was rotating on the turntable, the zero point a predetermined time before the start of traveling was detected when the vehicle started traveling 2. The gyro zero point correction method according to claim 1, wherein the correction value is set as a zero point correction value after the start of traveling. 10. The gyro zero point correcting method according to claim 1, wherein the gyro zero point correcting method is applied to a gyro output of a navigation device. A gyro that detects the current travel direction of the vehicle,
Stop determination means for determining that the vehicle has stopped;
A gyro zero having a gyro zero point correction value calculating unit for calculating a zero point correction value for correcting the zero point of the gyro by the output of the gyro when the stop determination unit detects that the vehicle is stopped. In the point correction device,
Gyro output threshold setting means for setting a threshold within a range within the gyro output when the vehicle is rotating on a turntable above and below the standard output value of the gyro,
The gyro output when the vehicle stop determining means detects that the vehicle is stopped is continuously exceeded from the time when it is detected that the output of the gyro is outside the threshold range set by the gyro output threshold setting means. An elapsed time calculating means for calculating an elapsed time after the gyro output threshold is exceeded,
When the elapsed time calculated by the elapsed time calculating means after exceeding the gyro output threshold does not exceed a predetermined time and the gyro output falls within the threshold range, it is determined that the vehicle is rotating on the turntable. And when the predetermined time is exceeded, the turn table rotation determining means for determining that the vehicle was not on the turn table,
A gyro zero point that sets the zero point correction value when the stop determination unit starts the vehicle stop determination as the subsequent zero point correction value when it is determined that the turn table upper rotation determination unit is not on the turn table A gyro zero point correction apparatus comprising a correction value setting means. 12. The gyro zero point correction device according to claim 11, wherein the stop determination unit determines that the vehicle has stopped when the output of the gyro is within a certain range for a predetermined time. 12. The gyro zero point correction apparatus according to claim 11, wherein the stop determination unit detects and determines a vehicle speed pulse. 12. The gyro zero point correction apparatus according to claim 11, wherein the gyro zero point correction value calculation means calculates the average value data of the gyro output. Gyro output zero point correction value storage means for storing the zero point correction value calculated by the gyro zero point correction value calculation means;
12. The gyro zero point correction value setting means takes in a zero point correction value at the start of stop determination stored in the gyro output zero point correction value storage means and sets it as a zero point correction value. Gyro zero point correction device. In the gyro zero point correction value setting means, when the turn table rotation determination means determines that the vehicle is rotating on the turn table, the zero point correction value before the stop determination is performed by the stop determination means The gyro zero point correction apparatus according to claim 11, wherein The gyro zero point correction value setting means sets the zero point correction value at the time of stoppage determination as a subsequent zero point correction value when the gyro output does not exceed the threshold after the stop determination is made by the stop determination means. 12. A gyro zero point correction apparatus according to claim 11, wherein In the gyro zero point correction value setting means, after the stop determination is made by the stop determination means, when the gyro output does not exceed the threshold, and when the vehicle starts to run after that, a predetermined time when the start of travel is detected 12. The gyro zero point correction device according to claim 11, wherein the previous zero point correction value is set as a subsequent zero point correction value. In the gyro zero point correction value setting means, when it is determined that the vehicle has been rotated on the turntable by the turntable rotation determination means, when the vehicle starts running,
12. The gyro zero point correction device according to claim 11, wherein a zero point correction value before a predetermined time when the start of traveling is detected is set as a zero point correction value after the start of traveling. 20. The gyro zero point correction device according to claim 11, wherein the gyro zero point correction device is applied to a gyro output of a navigation device.

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