JP6965720B2 - Position detection device and position detection program - Google Patents

Description

The disclosure herein relates to position detection techniques used in mobiles.

Conventionally, for example, Patent Document 1 discloses a three-dimensional position estimation device that receives a positioning signal transmitted from a positioning satellite and measures the position of a moving body. This three-dimensional position estimation device includes a processing device that creates gyro displacement amount data using a signal of a gyro for inertial guidance. The three-dimensional position estimation device uses the already measured three-dimensional coordinate data and the gyro displacement amount data to generate new three-dimensional data of the moving body when an abnormality occurs in the receiver that receives the positioning radio wave. Calculate.

Japanese Unexamined Patent Publication No. 6-66920

When the positioning signal is interrupted, the three-dimensional position estimation device of Patent Document 1 can perform dead reckoning using the three-dimensional coordinate data immediately before the interruption, that is, the satellite positioning position as a starting point and the gyro displacement amount data. However, just before the interruption of such a positioning signal, the error of satellite positioning tends to increase. Therefore, in the three-dimensional position estimation device of Patent Document 1, the dead reckoning is carried out starting from the satellite positioning position having a large error, and it may be difficult to secure the accuracy of the estimated position by the dead reckoning.

An object of the present disclosure is to provide a position detection device and a position detection program capable of suppressing a decrease in accuracy of an estimated position due to dead reckoning.

In order to achieve the above object, one disclosed embodiment is used in the moving body (A), positioning using a positioning signal transmitted from a positioning satellite (PS) , and an autonomous sensor mounted on the moving body ( A position detection device capable of positioning by guess navigation using the measurement results of 12 and 32), and a position acquisition unit (41) and a position acquisition unit that repeatedly acquire satellite positioning positions (Q) based on positioning signals. The trajectory estimation unit (42) that estimates the relative trajectory indicating the trajectory of the position of the moving object using the estimation navigation, starting from the individual satellite positioning positions acquired in From the trajectory, the trajectory holding unit (44) that holds the relative trajectory that minimizes the sum of the satellite positioning error (E) that occurs at the satellite positioning position and the estimated navigation error (tS) that occurs in the relative trajectory, and the positioning signal A position calculation unit (47) that inherits the relative trajectory held by the trajectory holding unit and calculates the estimated position of the moving object based on the estimated navigation when the locus is interrupted , and the position acquisition unit is a positioning signal. With respect to the reception state of, it is determined whether or not the low reliability condition predetermined as the accuracy of the satellite positioning position deteriorates is satisfied, and the trajectory holding unit is the absolute position on the relative trajectory estimated by the trajectory estimation unit. It has a storage area (45) that stores a certain storage position (P) and a storage error (M) that is an error of the storage position, and the storage error stored in the storage area and the latest acquired by the position acquisition unit. The reception state of the positioning signal is low by repeating the storage process in which the sum of the satellite positioning error and the estimated navigation error on the one with the smaller value is stored in the storage area as a new storage error by comparing with the satellite positioning error that occurs at the satellite positioning position. when the reliability condition is satisfied, is it cancel the comparison of memory errors and satellite positioning error position detector.
Further, one disclosed aspect is used in the moving body (A), and positioning using a positioning signal transmitted from a positioning satellite (PS) and measurement of an autonomous sensor (12, 32) mounted on the moving body. It is a position detection device that can perform positioning by guess navigation using the results, and the position acquisition unit (41) that repeatedly acquires the satellite positioning position (Q) based on the positioning signal, and the individual acquired by the position acquisition unit. From the trajectory estimation unit (42) that estimates the relative trajectory indicating the trajectory of the position of the moving object using the estimation navigation, and the relative trajectory estimated by the trajectory estimation unit, starting from the satellite positioning position of the satellite. A locus holding unit (44) that holds a relative locus that minimizes the sum of the satellite positioning error (E) that occurs at the positioning position and the estimated navigation error (tS) that occurs in the relative locus, and the locus when the positioning signal is interrupted. A position calculation unit (47) that inherits the relative trajectory held by the holding unit and calculates the estimated position of the moving object based on the estimated navigation is provided, and the position acquisition unit positions the positioning signal reception state. It is determined whether or not the high reliability condition predetermined as ensuring the accuracy of the signal is satisfied, and the locus holding unit is a storage position (P) which is an absolute position on the relative locus estimated by the locus estimation unit. It also has a storage area (45) that stores a storage error (M), which is an error of the storage position, and occurs in the storage error stored in the storage area and the latest satellite positioning position acquired by the position acquisition unit. When the storage process of comparing with the satellite positioning error and storing the sum of the satellite positioning error and the estimated navigation error on the one with the smaller value as a new storage error in the storage area is repeated, and the reception state of the positioning signal satisfies the high reliability condition. In addition, it is a position detection device that stops the comparison between the storage error and the satellite positioning error.

Further, one aspect disclosed is positioning using a positioning signal transmitted from a positioning satellite (PS) and speculative navigation using measurement results of an autonomous sensor (12, 32) mounted on a moving object (A). It is a position detection program that includes a process to be executed by a computer mounted on a moving object capable of positioning by, and the process is an acquisition step of repeating acquisition of a satellite positioning position (Q) based on a positioning signal, and an acquisition step. Starting from the acquired individual satellite positioning position, the satellite positioning position is selected from the estimation step that estimates the relative trajectory indicating the trajectory of the position of the moving object using the estimation navigation and the relative trajectory estimated in the estimation step. The holding step that holds the relative trajectory that minimizes the sum of the satellite positioning error (E) that occurs in the satellite positioning error (E) and the estimated navigation error (tS) that occurs in the relative trajectory, and the relative held in the holding step when the positioning signal is interrupted. inherits the trajectory, it possesses a calculating step of calculating an estimated position of the moving object based on dead reckoning, and in the acquisition step, the reception state of the positioning signal, previously defined as the accuracy of the satellite positioning position deteriorates In the holding step, it is determined whether or not the low reliability condition is satisfied, and in the holding step, the storage position (P) which is the absolute position on the relative trajectory estimated by the estimation step and the storage error (M) which is the error of the storage position. Is stored in the storage area (45), and the storage error stored in the storage area is compared with the satellite positioning error that occurs at the latest satellite positioning position acquired in the acquisition step. And the position to stop the comparison between the storage error and the satellite positioning error when the storage process of storing the sum of the estimated navigation errors as a new storage error in the storage area is repeated and the reception state of the positioning signal satisfies the low reliability condition. It is a detection program.
Further, one aspect disclosed is positioning using a positioning signal transmitted from a positioning satellite (PS) and speculative navigation using measurement results of an autonomous sensor (12, 32) mounted on a moving object (A). It is a position detection program that includes a process to be executed by a computer mounted on a moving object capable of positioning by, and the process is an acquisition step of repeating acquisition of a satellite positioning position (Q) based on a positioning signal, and an acquisition step. Starting from the acquired individual satellite positioning position, the satellite positioning position is selected from the estimation step that estimates the relative trajectory indicating the trajectory of the position of the moving object using the estimation navigation and the relative trajectory estimated in the estimation step. The holding step that holds the relative trajectory that minimizes the sum of the satellite positioning error (E) that occurs in the satellite positioning error (E) and the estimated navigation error (tS) that occurs in the relative trajectory, and the relative held in the holding step when the positioning signal is interrupted. It has a calculation step that inherits the trajectory and calculates the estimated position of the moving object based on the estimated navigation, and in the acquisition step, it is defined in advance that the accuracy of the positioning signal is ensured with respect to the reception state of the positioning signal. In the holding step, it is determined whether or not the high reliability condition is satisfied, and in the holding step, the storage position (P) which is the absolute position on the relative trajectory estimated by the estimation step and the storage error (M) which is the error of the storage position. Is stored in the storage area (45), and the storage error stored in the storage area is compared with the satellite positioning error that occurs at the latest satellite positioning position acquired in the acquisition step. And the position to stop the comparison between the storage error and the satellite positioning error when the storage process of storing the sum of the estimated navigation errors as a new storage error in the storage area is repeated and the reception state of the positioning signal satisfies the high reliability condition. It is a detection program.

In these aspects, the relative trajectory based on the dead reckoning starting from each satellite positioning position is estimated, and the relative trajectory that minimizes the sum of the satellite positioning error and the dead reckoning error is generated in the trajectory holding unit or in the holding step. , Will be retained. When the positioning signal transmitted from a positioning satellite is disrupted, the position calculating unit or calculation steps, retained by the estimated position based on dead reckoning inherit the relative trajectory Ru is calculated.

According to the above processing, even if the satellite positioning error increases when the positioning signal is interrupted, the satellite positioning position before the increase in the satellite positioning error is determined without starting from the satellite positioning position having a large satellite positioning error. Dead reckoning as a starting point becomes possible. Therefore, the decrease in accuracy of the estimated position due to dead reckoning is suppressed.

The reference numbers in parentheses are merely examples of the correspondence with the specific configuration in the embodiment described later, and do not limit the technical scope at all.

It is a figure which shows the whole image of the satellite positioning system roughly. It is a block diagram which shows the electric structure of an on-board unit. It is a flowchart which shows the detail of the position detection processing performed in the processing circuit. It is a time chart showing the process of performing the calculation process of the relative locus before the interruption of the satellite signal and selecting the relative locus with the minimum error at the time of the interruption of the satellite signal in chronological order.

The vehicle-mounted device 100 according to the embodiment of the present disclosure shown in FIGS. 1 and 2 is used in the vehicle A which is a moving body. The on-board unit 100 is one of the electronic control units mounted on the vehicle A, and has a function of a position detection device that positions the current position of the vehicle A by using a positioning signal transmitted from the positioning satellite PS. .. The vehicle-mounted device 100 is directly or indirectly electrically connected to the GNSS (Global Navigation Satellite System) antenna 11 and the wheel speed sensor 12 mounted on the vehicle A.

The GNSS antenna 11 receives radio waves (carrier waves) transmitted from the positioning satellite PS. Positioning signals for satellite positioning such as codes and messages are carried on the carrier wave. The positioning satellite PS is a satellite belonging to any of satellite positioning systems such as GPS, GLONASS, Galileo, IRNSS, QZSS, and Beidou. The GNSS antenna 11 converts the carrier waves received from the plurality of positioning satellites PS into electrical signals and outputs them to the vehicle-mounted device 100.

The wheel speed sensor 12 is provided on a hub bearing or the like of the vehicle A, and detects the rotation of the wheels of the vehicle A. The wheel speed sensor 12 functions as an autonomous sensor that detects the traveling state of the vehicle A. The wheel speed sensor 12 has a rotor that rotates with the wheels and a detection unit that is fixed to the vehicle body side. The wheel speed sensor 12 measures the difference in rotational speed generated between the rotor and the detection unit as the rotational speed of the wheels. The wheel speed sensor 12 outputs a pulse signal indicating the rotation speed of the wheels, that is, the vehicle speed of the vehicle A, toward the vehicle-mounted device 100.

The on-board unit 100 can identify the current position of the vehicle A with high accuracy by combining satellite positioning using a positioning signal with positioning by dead reckoning using the measurement result of an autonomous sensor. The vehicle-mounted device 100 includes a GNSS receiver 31, a gyro sensor 32, a memory device 50, a processing circuit 40, and the like.

The GNSS receiver 31 demodulates the electric signal provided from the GNSS antenna 11 and acquires the positioning signal carried on the carrier wave. The GNSS receiver 31 uses the positioning signals transmitted from the individual positioning satellites PS to generate observation data of the positioning satellite PS that can be captured from the vehicle A. The observation data is, for example, data showing a satellite number, an observation time, a Doppler shift amount, a pseudo distance, satellite coordinates, a carrier phase, and the like. The GNSS receiver 31 sequentially outputs the generated observation data to the position acquisition unit 41.

The gyro sensor 32 is a sensor that detects the angular velocity as a voltage value. The gyro sensor 32, together with the wheel speed sensor 12, functions as an autonomous sensor that detects the traveling state of the vehicle A. The gyro sensor 32 measures the magnitude of the angular velocity generated around, for example, the vertical axis (yaw axis) among the three orthogonal axes defined for the vehicle A. The gyro sensor 32 sequentially outputs the measured angular velocity data to the processing circuit 40.

The memory device 50 is mainly composed of a non-transitionary tangible storage medium such as a flash memory and a hard disk drive. The memory device 50 stores a large amount of data so that it can be read by the processing circuit 40. As an example, the memory device 50 stores various application programs and the like executed by the processing circuit 40.

The processing circuit 40 is mainly composed of a microcomputer having a processor that executes arithmetic processing, a RAM that functions as a work area for arithmetic operations by the processor, a bus that connects them, and the like. The processing circuit 40 reads an application program (hereinafter, “position detection program”) that realizes a function as a position detection device from the memory device 50, and causes the processor to execute the application program. By executing the position detection program by the processor, the processing circuit 40 has functional blocks such as a position acquisition unit 41, a locus estimation unit 42, an error estimation unit 43, a locus holding unit 44, and a position calculation unit 47.

The position acquisition unit 41 repeats the acquisition of the satellite positioning position Q based on the positioning signal by using the observation data generated by the GNSS receiver 31. The position acquisition unit 41 acquires the traveling speed and the traveling direction based on the transition of the observation data over time. In the state of satellite positioning where the positioning signal is not interrupted, the latest satellite positioning position Q acquired by the position acquisition unit 41 is set as the current position of the vehicle A and the on-board unit 100, and is outside the navigation device, the automatic driving device, or the like. Output to the device. In addition to acquiring the satellite positioning position Q, the position acquisition unit 41 estimates the error that occurs in the satellite positioning position Q and acquires the satellite positioning error E.

In addition, the position acquisition unit 41 grasps the state of the positioning signal and evaluates the reliability of the satellite positioning position Q. A low reliability condition and a high reliability condition are preset in the position acquisition unit 41. The position acquisition unit 41 determines that the satellite positioning position Q has low reliability when the reception state of the positioning signal satisfies the low reliability condition. On the other hand, the position acquisition unit 41 determines that the satellite positioning position Q has high reliability when the reception state of the positioning signal satisfies the high reliability condition.

Specifically, the reliability of the satellite positioning position Q is comprehensively determined based on the reception strength of the positioning signal, the number and arrangement of the positioning satellite PS in the captured state, the presence or absence of multipath, and the like. The low reliability condition is a condition defined in advance as the accuracy of the satellite positioning position Q deteriorates. As an example, when the reception strength of the positioning signal is weak, the number of positioning satellites PS in the captured state is small or low (the zenith angle is large), the influence of multipath is large, and other adverse conditions are combined. The position acquisition unit 41 determines that the reception state satisfies the low reliability condition.

On the other hand, the high reliability condition is a condition defined in advance that the accuracy of the satellite positioning position Q is ensured. As an example, when favorable conditions such as high reception intensity of positioning signal, large number or high number of positioning satellites PS in the captured state (small zenith angle), and small influence of multipath are combined. The position acquisition unit 41 determines that the reception state satisfies the high reliability condition. For convenience, the reliability when the reception state of the positioning signal does not satisfy both the low reliability condition and the high reliability condition is defined as "medium reliability".

The trajectory estimation unit 42 obtains a relative trajectory indicating a position change of the vehicle A using dead reckoning based on the information of the traveling direction acquired from the position acquisition unit 41 and the information acquired from the wheel speed sensor 12 and the gyro sensor 32. presume. The trajectory estimation unit 42 estimates the relative trajectory starting from each acquired satellite positioning position Q according to the cycle (epoch) in which the position acquisition unit 41 acquires the satellite positioning position Q.

Specifically, the locus estimation unit 42 calculates the moving speed of the vehicle A by using the pulse signal acquired from the wheel speed sensor 12. In addition, the trajectory estimation unit 42 calculates the yaw rate of the vehicle A using the angular velocity data acquired from the gyro sensor 32. The trajectory estimation unit 42 uses the traveling direction specified by the position acquisition unit 41, the calculated movement speed, and the yaw rate to obtain a relative position vector R indicating the amount of movement of the vehicle A per unit time based on dead reckoning. Set. The traveling direction specified from the positioning signal is used as the initial direction for calculating the initial value of the relative position vector R. The unit time is, for example, the acquisition cycle of the satellite positioning position Q. The locus estimation unit 42 estimates the relative locus using dead reckoning by the process of continuously integrating the relative position vector R starting from the specific satellite positioning position Q.

The error estimation unit 43 estimates the dead reckoning error tS that occurs in the relative trajectory. Since the dead reckoning error tS is time-dependent, the dead reckoning error tS increases monotonically as the elapsed time from the acquisition time of the satellite positioning position Q as the starting point of the relative trajectory increases. Calibration data for estimating the dead reckoning error tS is registered in the error estimation unit 43. The calibration data is data derived in advance by a test or calculation, and is data showing the correlation between the elapsed time in the dead reckoning using the measurement results of the wheel speed sensor 12 and the gyro sensor 32 and the dead reckoning error tS. The error estimation unit 43 estimates the error that occurs in the relative position vector R per unit time (hereinafter, “unit time estimation error S”) based on the calibration data. The value obtained by integrating the unit-time dead reckoning error S is the dead reckoning error tS that occurs in the dead reckoning.

The trajectory holding unit 44 has a sum of the satellite positioning error E that occurs in the satellite positioning position Q and the dead reckoning error tS that occurs in the relative trajectory from among a large number of relative trajectories estimated from each satellite positioning position Q. The minimum relative locus is selectively retained. On the other hand, the relative locus in which the sum of the satellite positioning error E and the dead reckoning error tS is not the minimum is sequentially rejected. The locus holding unit 44 has a storage area 45 for use in selectively holding a relative locus.

The storage area 45 is, for example, an area reserved on the RAM. The storage position P and the storage error M are stored in the storage area 45. The storage position P is an absolute position on the relative locus estimated by the locus estimation unit 42. The memory error M is an error occurring in the memory position P, and is the sum of the satellite positioning error E in the relative trajectory and the dead reckoning error tS. The locus holding unit 44 repeats updating each value of the storage position P and the storage error M by the position detection process (see FIG. 3) described later.

When the positioning signal received by the GNSS antenna 11 is interrupted, the position calculation unit 47 switches from satellite positioning to positioning based on dead reckoning, and continues to specify the current position of the vehicle A. When the position calculation unit 47 determines that the positioning signal is interrupted, the position calculation unit 47 inherits the relative locus held by the locus holding unit 44 and calculates the estimated position of the vehicle A based on the dead reckoning. As an example, when the number of satellite signals required for satellite positioning cannot be received and the position acquisition unit 41 cannot obtain a solution for the satellite positioning position Q, the position calculation unit 47 may perform the position calculation unit 47. , Judge that the positioning signal is interrupted.

The details of the position detection process performed in the above process circuit 40 will be described with reference to FIGS. 1 and 2 based on FIG. The position detection process is started based on, for example, the power of the vehicle-mounted device 100 being turned on, and is continuously repeated until the power of the vehicle-mounted device 100 is turned off. In the following description, each value at time T = n is referred to as satellite positioning position Qn, satellite positioning error En, relative position vector Rn, unit time estimation error Sn, storage position Pn, and storage error Mn. Further, the unit of each error is unified as, for example, "meter".

In S101, it is determined whether or not satellite positioning is possible. If it is determined in S101 that the positioning signal is interrupted and the satellite positioning position Qn cannot be positioned, the process proceeds to S109. On the other hand, if it is determined in S101 that the satellite positioning position Qn can be positioned, the process proceeds to S102.

In S102, the state of the received positioning signal is evaluated. If it is determined in S102 that the reception state of the positioning signal satisfies the low reliability condition, the process proceeds to S110. On the other hand, if it is determined in S102 that the reception state of the positioning signal satisfies the high reliability condition, the process proceeds to S114. Further, if it is determined in S102 that the reception state of the positioning signal does not satisfy both the low reliability condition and the high reliability condition (medium reliability), the process proceeds to S103.

In S103, the satellite positioning position Qn and the satellite positioning error En acquired by the position acquisition unit 41 are read, and the process proceeds to S104. In S104, the relative position vector Rn and the unit time estimation error Sn calculated by the locus estimation unit 42 are read, and the process proceeds to S105. In S105, the total value of the satellite positioning error En acquired in S103 and the unit time estimation error Sn acquired in S104 is calculated, and the process proceeds to S106. In S106, the storage error Mn-1 stored in the processing in the previous epoch (time T = n-1) is read from the storage area 45. Then, the total value of the storage error Mn-1 and the unit time estimation error Sn is calculated, and the process proceeds to S107.

In S107, the satellite positioning error En and the storage error Mn-1 are compared. For convenience, in S107, the total value En + Sn calculated in S105 and the total value Mn-1 + Sn calculated in S106 are compared. In S107, one of the two total values, whichever is smaller, is stored in the storage area 45 as a new storage error Mn, and the process proceeds to S108.

In S107 described above, the relative locus selectively held is compared with the relative locus starting from the latest satellite positioning position Qn, and one with high accuracy (small error) is determined. Then, the sum of the satellite positioning error E and the dead reckoning error tS on the one side determined to be highly accurate is stored in the storage area 45 as the latest storage error Mn.

In S108, the latest absolute position in the highly accurate relative locus selected in the comparison in S107 is stored in the storage area 45 as the storage position Pn. When the total value En + Sn is small, the absolute position obtained by adding the relative position vector Rn acquired in S104 to the satellite positioning position Qn acquired in S103 is stored as a new storage position Pn. On the other hand, when the total value Mn-1 + Sn is small, the storage position Pn-1 stored in the processing at the previous epoch (time T = n-1) is read from the storage area 45. Then, the absolute position obtained by adding the relative position vector Rn acquired in S104 to the storage position Pn-1 is stored as a new storage position Pn.

On the other hand, in the processing after S110 when the reception state of the positioning signal satisfies the low reliability condition, the comparison between the storage error Mn-1 and the satellite positioning error En is stopped, and it is estimated that the past satellite positioning position Q is the starting point. The relative trajectory based on navigation is maintained. Specifically, in S110, the relative position vector Rn and the unit time estimation error Sn are read in the same manner as in S104, and the process proceeds to S111.

In S111, the storage error Mn-1 is read out from the storage area 45, the total value of the storage error Mn-1 and the unit time estimation error Sn is calculated, and the process proceeds to S112. In S112, the total value Mn-1 + Sn calculated in S111 is stored in the storage area 45 as a new storage error Mn, and the process proceeds to S113. In S113, the storage position Pn-1 is read out from the storage area 45, and the absolute position obtained by adding the relative position vector Rn to the storage position Pn-1 is stored as a new storage position Pn.

Further, in the processing after S114 when the reception state of the positioning signal satisfies the high reliability condition, the comparison between the storage error Mn-1 and the satellite positioning error E is stopped, and the relative trajectory based on the latest satellite positioning position Qn is obtained. Be retained. Specifically, in S114, the satellite positioning position Qn and the satellite positioning error En are read in the same manner as in S103, and the process proceeds to S115. In S115, the relative position vector Rn and the unit time estimation error Sn are read in the same manner as in S104, and the process proceeds to S116. In S116, the total value of the satellite positioning error En and the unit time estimation error Sn is calculated in the same manner as in S105, and the process proceeds to S117. In S117, the total value En + Sn is stored in the storage area 45 as a new storage error Mn, and the process proceeds to S118. In S118, the absolute position obtained by adding the relative position vector Rn acquired in S115 to the satellite positioning position Qn acquired in S114 is stored as a new storage position Pn.

Then, in S109 when the positioning signal is interrupted, the process shifts to dead reckoning based on the storage position Px stored in the storage area 45. When the signal is interrupted at time T = x, the latest absolute position (relative locus) is calculated by sequentially integrating the relative position vectors Rx, Rx + 1, ... Per unit time into the storage position Px that is the starting point. To estimate.

In the above abnormality detection process, immediately after the start of the process (time T = 1) and immediately after returning from dead reckoning to satellite positioning, a large value that is not normally input is input to the memory error M as an initial value. By such initial processing, the total value of the satellite positioning position Q1 and the relative position vector R1 is stored in the storage area 45 as the first storage position P1 immediately after the processing is started and immediately after the return.

In the position detection method described so far, the relative trajectory based on the dead reckoning starting from each satellite positioning position Q is estimated, and the relative trajectory that minimizes the sum of the satellite positioning error E and the dead reckoning error tS holds the trajectory. It is held by the unit 44. Then, at the interruption time x when the positioning signal transmitted from the positioning satellite PS is interrupted, the position calculation unit 47 inherits the relative trajectory held by the trajectory holding unit 44 and calculates the estimated position based on the dead reckoning. do.

Specifically, as shown in FIG. 4, when the time from the increase of the satellite positioning error E to the interruption of the positioning signal is long, the relative trajectory starting from the satellite positioning position Q having a small satellite positioning error E is estimated. The navigation error tS increases. As a result, the relative trajectory LA starting from the satellite positioning position Qa at the stage when the satellite positioning error E becomes relatively large at the time a with a small time difference with respect to the interruption time x is held by the trajectory holding unit 44. .. Then, after the interruption time x, the calculation of the estimated position by the dead reckoning inheriting the relative trajectory LA is performed. In other words, at the time a before the interruption time x, the position estimation as if the dead reckoning was started is performed.

On the other hand, when the time from the increase of the satellite positioning error E to the interruption of the positioning signal is short, the relative trajectory LB starting from the satellite positioning position Qb at the time b when the satellite positioning error E is small is held by the trajectory holding unit 44. .. In addition, even when the satellite positioning error E immediately before the interruption increases remarkably due to observation data, satellite arrangement, multipath, etc., or when the reliability of the reception state is remarkably low, the satellite positioning position Qb is used as the starting point. The relative locus LB is held by the locus holding unit 44. Then, after the interruption time x, the calculation of the estimated position by the dead reckoning inheriting the relative trajectory LB is performed.

As described above, even if the satellite positioning error E increases when the positioning signal is interrupted, it does not start from the satellite positioning position Qx having a large satellite positioning error E, but before the increase in the satellite positioning error E (time b). ), Dead reckoning is possible starting from the satellite positioning position Qb. Therefore, the decrease in accuracy of the estimated position due to dead reckoning is suppressed.

In addition, in the present embodiment, the calibration data for calculating the dead reckoning error tS is derived in advance in consideration of the time dependence of the dead reckoning error tS generated in the dead reckoning. By using such time dependence, the error estimation unit 43 can accurately estimate the dead reckoning error tS. As a result, the locus holding unit 44 can reject the accumulated movement locus of the dead reckoning error tS when the increase period of the satellite positioning error E is long, and can select the relative locus LA having a small dead reckoning error tS as the holding target. Therefore, the decrease in the accuracy of the estimated position after switching from satellite positioning to dead reckoning is further suppressed.

Further, in the present embodiment, by repeating the update of the storage position P and the storage error M, the locus holding unit 44 selectively holds the relative locus that minimizes the error, and sequentially rejects other relative loci having a large error. I will do it. With such processing, the most accurate relative locus can be maintained while reducing the storage area 45 required for the calculation.

Further, in the present embodiment, when the satellite positioning error En is smaller than the storage error Mn-1, the estimated position obtained by adding the relative position vector Rn to the satellite positioning position Qn is acquired as the latest absolute position. That is, in a situation where the satellite positioning error E is small, the estimated position starting from the latest satellite positioning position Q is stored in the storage area 45 as the storage position P. According to the above, the locus holding unit 44 can continuously hold the relative locus in which the accumulation of the dead reckoning error tS is suppressed. Therefore, after switching from satellite positioning to dead reckoning, the accuracy of the estimated position can be ensured.

On the other hand, when the storage error Mn-1 is smaller than the satellite positioning error En, the estimated position obtained by adding the relative position vector R to the storage position Pn-1 is acquired as the latest absolute position. That is, in a situation where the satellite positioning error E is large, the estimated position starting from the satellite positioning position Qb before the satellite positioning error E increases can be stored in the storage area 45. Based on the above, the situation where dead reckoning is performed starting from the satellite positioning position Qx where the satellite positioning error E has increased is avoided.

In addition, in the present embodiment, when the reception state of the positioning signal satisfies the low reliability condition, the comparison between the immediately preceding storage error Mn-1 and the satellite positioning error En is stopped. Further, even when the reception state of the positioning signal satisfies the high reliability condition, the comparison between the immediately preceding storage error Mn-1 and the satellite positioning error En is stopped. According to the above, unnecessary comparison processing can be omitted, so that the calculation load in the processing circuit 40 can be reduced.

Then, when the reception state of the positioning signal satisfies the low reliability condition, the estimated position obtained by adding the relative position vector Rn to the storage position Pn-1 is stored as a new storage position Pn. In such a process, the estimated position starting from the satellite positioning position Q having a small satellite positioning error E is continuously stored in the storage area 45 while omitting the step for error comparison. Therefore, even if the calculation load of the processing circuit 40 is reduced, it is possible to avoid the execution of the dead reckoning starting from the low-precision satellite positioning position Qx.

Further, when the reception state of the positioning signal satisfies the high reliability condition, the estimated position obtained by adding the relative position vector Rn to the satellite positioning position Qn is stored as a new storage position Pn. In such a process, the locus holding unit 44 can continuously hold the relative locus in which the accumulation of the dead reckoning error tS is suppressed while omitting the step for error comparison. Therefore, the accuracy of the estimated position can be ensured even after switching to dead reckoning.

In the above embodiment, the vehicle A corresponds to the "moving body", the wheel speed sensor 12 and the gyro sensor 32 correspond to the "autonomous sensor", the processing circuit 40 corresponds to the "processing unit", and the relative position vector. R corresponds to the "moving portion", and the on-board unit 100 corresponds to the "position detecting device".

(Other embodiments)
Although one embodiment according to the present disclosure has been described above, the present disclosure is not construed as being limited to the above embodiment, and is applied to various embodiments and combinations within the scope of the gist of the present disclosure. be able to.

In the above embodiment, a process of holding the storage position P and the storage error M in the storage area 45 is performed in order to hold the calculation process of the relative locus with the highest accuracy. However, if it is possible to execute a plurality of relative trajectory calculation processes from the stage where the accuracy of satellite positioning is good before the positioning signal is interrupted and select the relative trajectory calculation process that has the minimum error at the time of interruption, it is concrete. The details of the process may be changed as appropriate. Further, the trajectory holding unit 44 of the above embodiment selectively holds only the relative trajectory calculation process that minimizes the sum of the satellite positioning error E and the dead reckoning error tS, and rejects all other relative trajectory calculation processes. Was there. However, if at least the calculation process of the minimum error is held, the calculation process of the relative trajectory to be held does not have to be one.

In the above embodiment, the cumulative dead reckoning error tS is calculated by integrating the unit time dead reckoning error Sn based on the time dependence of the dead reckoning. However, the dead reckoning error tS that occurs in the relative trajectory may be calculated using only the elapsed time after the transition to dead reckoning, for example, as a parameter. As an example, when the change in the moving speed of the vehicle A is relatively large, the dead reckoning error tS should be calculated by integrating the unit time dead reckoning error Sn. On the other hand, when the vehicle A is cruising at a constant speed, the dead reckoning error tS may be acquired by a calculation using only the elapsed time.

In the above embodiment, when the satellite positioning error E is clearly large, or when the satellite positioning error E is clearly small, the step of comparing the satellite positioning error and the storage error, that is, the process of comparing the calculation processes of the relative trajectories. Was omitted. However, each determination of the low reliability condition and the high reliability condition regarding the reception state of the positioning signal does not have to be performed. The processing circuit may always perform a process of selecting the calculation process of the relative locus without evaluating the positioning signal.

Further, in the position detection process of the above embodiment, after adding the unit time estimation error to each of the satellite positioning error and the past storage error, one of the smaller total values is stored as a new storage error (see S107). ). However, the process of adding the unit time estimation error to each error (see S105 and S106) may be omitted. In such a modification, the value obtained by adding the unit time estimation error to the smaller one of the satellite positioning error and the past storage error is stored as a new storage error.

The satellite positioning error E in the above embodiment may be calculated using a general algorithm. Specifically, the satellite positioning error E is determined by the measurement accuracy of the pseudo distance (distance measurement accuracy) and the geometrical positional relationship between the in-vehicle device 100 and the positioning satellite PS. Therefore, the position acquisition unit 41 can set the satellite positioning error E by combining the distance measurement accuracy of the on-board unit 100 with, for example, the accuracy deterioration index (Dilution of Precision, DOP) which is an index of the positioning accuracy.

The GNSS receiver 31 and the position acquisition unit 41 of the above embodiment calculated the satellite positioning position Q by code positioning. However, the satellite positioning position Q may be specified by carrier phase positioning.

The autonomous sensor used in dead reckoning is not limited to the wheel speed sensor and the gyro sensor of the above embodiment. For example, an acceleration sensor or the like that detects acceleration in the front-rear direction and the lateral direction acting on the vehicle A may be provided as an autonomous sensor. Further, a camera, a radar, a rider, etc. that recognize the surrounding environment of the vehicle A may be provided as an autonomous sensor that provides the on-board unit with information necessary for dead reckoning. The trajectory holding unit has a configuration capable of acquiring a time-dependent dead reckoning error according to the configuration of the autonomous sensor used for dead reckoning.

The configuration of the position detection device is not limited to the vehicle-mounted device of the above embodiment, and can be changed as appropriate. For example, the on-board unit as a position detection device may have a configuration corresponding to a processing circuit, and may not include, for example, a GNSS receiver and a gyro sensor. In addition, moving objects for which position detectors are used include mobile terminals carried by humans, bicycles, freight vehicles (trucks), tractors, motorcycles (motorcycles), buses, construction machinery, agricultural machinery, ships, aircraft, helicopters, etc. Trains, streetcars, etc. may be included.

In the above embodiment, the memory device that stores the position detection program does not have to be a storage medium built in the vehicle-mounted device, and may be in the form of, for example, a memory card. That is, the storage medium may be inserted into a slot portion provided in the vehicle-mounted device and electrically connected to the processing circuit. Further, the storage medium for storing the position detection program is not limited to the storage medium such as the ECU mounted on the vehicle, and may be an optical disk as a copy source to the storage medium, a hard disk drive of a general-purpose computer, or the like.

12 Wheel speed sensor (autonomous sensor), 32 Gyro sensor (autonomous sensor), 40 Processing circuit (processing unit), 41 Position acquisition unit, 42 Trajectory estimation unit, 43 Error estimation unit, 44 Trajectory holding unit, 45 Storage area, 47 Position calculation unit, 100 in-vehicle device (position detection device), A vehicle (moving body), PS positioning satellite, P, Pn storage position, M, Mn storage error, Q, Qn satellite positioning position, E, En satellite positioning error, R, Rn Relative position vector (movement), tS Dead reckoning error

Claims (10)

Positioning using the positioning signal used in the mobile body (A) and transmitted from the positioning satellite (PS) and positioning by dead reckoning using the measurement results of the autonomous sensors (12, 32) mounted on the mobile body. It is a position detection device that can
A position acquisition unit (41) that repeatedly acquires a satellite positioning position (Q) based on the positioning signal, and
Wherein a starting point each of the satellite positioning position acquired by the position acquisition unit, the relative trajectory indicating the locus of the position of the movable body, the trajectory estimation unit that estimates using dead reckoning and (42),
From the relative trajectories estimated by the locus estimation unit, the relative locus that minimizes the sum of the satellite positioning error (E) that occurs at the satellite positioning position and the dead reckoning error (tS) that occurs at the relative locus is obtained. Trajectory holding unit (44) to be held and
A position calculation unit (47) that inherits the relative locus held by the locus holding unit and calculates an estimated position of the moving body based on dead reckoning when the positioning signal is interrupted is provided .
The position acquisition unit determines whether or not the reception state of the positioning signal satisfies a low reliability condition predetermined as the accuracy of the satellite positioning position deteriorates.
The locus holding portion is
It has a storage area (45) for storing a storage position (P) which is an absolute position on the relative locus and a storage error (M) which is an error of the storage position estimated by the locus estimation unit.
The storage error stored in the storage area is compared with the satellite positioning error generated at the latest satellite positioning position acquired by the position acquisition unit, and the satellite positioning error and the estimation in the smaller value are compared. The storage process of storing the sum of the navigation errors as the new storage error in the storage area is repeated.
If the positioning signal reception state is the low reliability satisfying, it cancels the comparison of the satellite positioning error and the memory error position detector. When the reception state of the positioning signal satisfies the low reliability condition, the locus holding unit adds the movement amount (R) estimated by dead reckoning to the storage position read from the storage area to obtain the estimated position. The position detection device according to claim 1 , wherein the new storage position on the relative locus is stored in the storage area. The position acquisition unit determines whether or not the reception state of the positioning signal satisfies a high reliability condition predetermined as ensuring the accuracy of the positioning signal.
The position detection device according to claim 1 or 2 , wherein the locus holding unit stops comparison between the storage error and the satellite positioning error when the reception state of the positioning signal satisfies the high reliability condition. Positioning using the positioning signal used in the mobile body (A) and transmitted from the positioning satellite (PS) and positioning by dead reckoning using the measurement results of the autonomous sensors (12, 32) mounted on the mobile body. It is a position detection device that can
A position acquisition unit (41) that repeatedly acquires a satellite positioning position (Q) based on the positioning signal, and
Wherein a starting point each of the satellite positioning position acquired by the position acquiring unit, a relative trajectory indicating the locus of the position of the movable body, the trajectory estimation unit that estimates using dead reckoning and (42),
From the relative trajectories estimated by the locus estimation unit, the relative locus that minimizes the sum of the satellite positioning error (E) that occurs at the satellite positioning position and the dead reckoning error (tS) that occurs at the relative locus is obtained. Trajectory holding unit (44) to be held and
A position calculation unit (47) that inherits the relative locus held by the locus holding unit and calculates an estimated position of the moving body based on dead reckoning when the positioning signal is interrupted is provided .
The position acquisition unit determines whether or not the reception state of the positioning signal satisfies a high reliability condition predetermined as ensuring the accuracy of the positioning signal.
The locus holding portion is
It has a storage area (45) for storing a storage position (P) which is an absolute position on the relative locus and a storage error (M) which is an error of the storage position estimated by the locus estimation unit.
The storage error stored in the storage area is compared with the satellite positioning error generated at the latest satellite positioning position acquired by the position acquisition unit, and the satellite positioning error and the estimation in the smaller value are compared. The storage process of storing the sum of the navigation errors as the new storage error in the storage area is repeated.
If the positioning signal reception state is the high degree of satisfying, it cancels the comparison of the satellite positioning error and the memory error position detector. When the reception state of the positioning signal satisfies the high reliability condition, the trajectory holding unit adds the movement amount (R) estimated by dead reckoning to the latest satellite positioning position, and the estimated position is relative to the estimated position. The position detection device according to claim 3 or 4 , which is stored in the storage area as a new storage position on the locus. When the satellite positioning error is smaller than the memory error, the trajectory holding unit adds the movement amount (R) estimated by dead reckoning to the latest satellite positioning position, and sets the estimated position on the relative trajectory. The position detection device according to any one of claims 1 to 5, which is stored in the storage area as a new storage position. The track holding unit, when the satellite the storage error than the positioning error is small, the estimated position obtained by adding the movement amount estimated by dead reckoning the (R) in the storage position read from the storage area, the relative The position detecting device according to any one of claims 1 to 6, which is stored in the storage area as a new storage position on the locus. An error estimation unit that stores the time dependence derived in advance for the dead reckoning error that occurs in the dead reckoning using the autonomous sensor, and estimates the dead reckoning error that occurs in the relative trajectory using the time dependence. (43) The position detecting device according to any one of claims 1 to 7, further comprising. The mobile body capable of positioning using a positioning signal transmitted from a positioning satellite (PS) and positioning by dead reckoning using the measurement results of the autonomous sensors (12, 32) mounted on the mobile body (A). It is a position detection program that includes processing to be executed by the computer installed in the
The above processing
An acquisition step that repeats acquisition of the satellite positioning position (Q) based on the positioning signal, and
An estimation step of the the starting point is individual of the satellite positioning position acquired by the acquisition step, the relative trajectory indicating the locus of the position of the moving body, estimated using dead reckoning,
From the relative trajectories estimated in the estimation step, the relative locus that minimizes the sum of the satellite positioning error (E) that occurs at the satellite positioning position and the dead reckoning error (tS) that occurs at the relative locus is held. Holding steps and
When the positioning signal is disrupted, by inheriting the relative trajectory held in said holding step, have a, a computing step of computing an estimated position of the moving object based on dead reckoning,
In the acquisition step, it is determined whether or not the reception state of the positioning signal satisfies the low reliability condition predetermined as the accuracy of the satellite positioning position deteriorates.
In the holding step,
The storage position (P), which is an absolute position on the relative locus, and the storage error (M), which is an error of the storage position, estimated by the estimation step are stored in the storage area (45).
The storage error stored in the storage area is compared with the satellite positioning error generated at the latest satellite positioning position acquired in the acquisition step, and the satellite positioning error and the estimated navigation in the smaller value are compared. The storage process of storing the sum of the errors as the new storage error in the storage area is repeated.
A position detection program that stops comparison between the storage error and the satellite positioning error when the reception state of the positioning signal satisfies the low reliability condition. The mobile body capable of positioning using a positioning signal transmitted from a positioning satellite (PS) and positioning by dead reckoning using the measurement results of the autonomous sensors (12, 32) mounted on the mobile body (A). It is a position detection program that includes processing to be executed by the computer installed in the
The above processing
An acquisition step that repeats acquisition of the satellite positioning position (Q) based on the positioning signal, and
An estimation step of the the starting point is individual of the satellite positioning position acquired by the acquisition step, the relative trajectory indicating the locus of the position of the moving body, estimated using dead reckoning,
From the relative trajectories estimated in the estimation step, the relative locus that minimizes the sum of the satellite positioning error (E) that occurs at the satellite positioning position and the dead reckoning error (tS) that occurs at the relative locus is held. Holding steps and
When the positioning signal is disrupted, by inheriting the relative trajectory held in said holding step, have a, a computing step of computing an estimated position of the moving object based on dead reckoning,
In the acquisition step, it is determined whether or not the reception state of the positioning signal satisfies the high reliability condition predetermined as ensuring the accuracy of the positioning signal.
In the holding step,
The storage position (P), which is an absolute position on the relative locus, and the storage error (M), which is an error of the storage position, estimated by the estimation step are stored in the storage area (45).
The storage error stored in the storage area is compared with the satellite positioning error generated at the latest satellite positioning position acquired in the acquisition step, and the satellite positioning error and the estimated navigation in the smaller value are compared. The storage process of storing the sum of the errors as the new storage error in the storage area is repeated.
A position detection program that stops comparison between the storage error and the satellite positioning error when the reception state of the positioning signal satisfies the high reliability condition.

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