JP5118177B2 - Moving body high-accuracy speed measuring apparatus and method - Google Patents

Description

  The present invention relates to a moving body high-accuracy speed measuring apparatus and method.

  In recent years, a global positioning system called GPS (Global Positioning System) is known as a system for measuring a position on the earth. In the GPS system, a GPS receiver receives radio waves from an artificial satellite over the earth, and immediately measures the current position from the time difference of the received radio waves. If such a GPS receiver is used, the speed of the moving body can be measured.

  The method of measuring the speed of a moving object using a GPS receiver includes (1) a method of obtaining speed by differentiating position information calculated by the GPS receiver, and (2) movement of a satellite and movement of the moving object. There is a method for calculating the Doppler speed from the Doppler shift amount of the GPS carrier wave. Normally, the method (1) has a high accuracy because the position accuracy at the time of independent positioning is about several tens of meters and about several tens of centimeters when using DGPS (Differential GPS).

  Although the method (2) enables high-accuracy speed measurement, the conditions for measurement are limited. For example, when a signal from a GPS satellite is reflected by trees, buildings, etc. and affected by multipath, the PLL (PLL: Phase-locked loop phase synchronization circuit) in the receiver is unlocked. Because large noise is superimposed on the speed output, high-accuracy speed measurement cannot be expected in a place where the influence of multipath is large. Also, the method (2) cannot measure the speed when the satellite signal is momentarily interrupted.

  For example, FIG. 7 is a diagram showing the speed of a car moving on a public road by the Doppler speed from a GPS receiver. As shown in FIG. 7, the speed output becomes zero due to the influence of trees, and the satellite signal from the GPS is interrupted when passing through a viaduct or the like, so the speed output becomes zero. From the above, it has been difficult to measure the speed with high accuracy using only the Doppler speed in the situation where various radio disturbances such as public roads occur.

  To deal with such a problem, for example, the speed measurement device disclosed in Patent Document 1 fuses the Doppler velocity by GPS and the velocity by an IMU (Internal Measurement Unit) using a Kalman filter, and then DOP (satellite). The accuracy of the GPS signal is used to determine whether the GPS signal is good or not, and a high-accuracy speed is output by switching between outputting a Doppler speed or outputting an IMU speed.

JP 2008-175730 A

  However, the DOP value is merely an accuracy index based on the arrangement status (geometric arrangement) of the satellite, and is not an index that can determine the influence of multipath. Further, the correlation between DOP and the Doppler speed is small, and the reliability as an accuracy index of the Doppler speed is small. Furthermore, since the DOP value is calculated from the satellite arrangement status, the DOP change is not instantaneous. For this reason, the speed measurement device disclosed in Patent Document 1 cannot determine instantaneous noise of Doppler speed due to multipath or the like in a place where the influence of multipath due to a building group or a tree stand is greatly considered.

  Accordingly, there is a need for an apparatus and a method for determining whether Doppler speed information obtained from a GPS receiver is good or not and outputting a highly accurate and reliable speed in real time.

  It is an object of the present invention to provide a moving body high-accuracy speed measuring apparatus and method for determining whether Doppler speed information obtained from a GPS receiver is good or not and outputting high-accuracy and high-reliability speed in real time.

  The present invention provides the following solutions.

  (1) A moving body high-accuracy speed measuring device that measures the speed of a moving body, the acceleration measuring means for measuring the acceleration and angular velocity of the moving body using an IMU, and the movement measured by the acceleration measuring means. The mobile body calculates the speed by the strapdown calculation from the acceleration and angular velocity of the body, calculates the real-time interpolation speed based on the calculated speed, and the moving body from the Doppler shift amount of the GPS carrier using the GPS receiver. A difference between a speed measuring means for measuring the Doppler speed, an acceleration calculated from the Doppler speed measured by the speed measuring means, and an acceleration measured by the acceleration measuring means, and based on the calculated difference A pass / fail coefficient calculating means for calculating a coefficient, and the coefficient by the pass / fail coefficient calculating means. Delay processing means for delaying the time to use the Doppler speed measured by the speed measuring means for calculation by the time for calculation, the Doppler speed delayed by the delay processing means, and the strapdown navigator means The synchronization processing means that performs synchronization with the real-time interpolation speed fed back from and calculates an error amount between the synchronized Doppler speed and the real-time interpolation speed, and the synchronization processing means that is calculated by the synchronization processing means A pass / fail coefficient multiplying unit for multiplying the error amount by the coefficient calculated by the pass / fail coefficient calculating unit, and an adjustment amount for the real-time interpolation speed based on the error amount multiplied by the coefficient by the pass / fail coefficient multiplying unit by a Kalman filter. Kalman filter means for performing an estimation calculation The strapdown navigator means calculates the real-time interpolation speed by combining the speed calculated by the strapdown calculation with the adjustment amount estimated by the Kalman filter means, and calculates the real-time interpolation speed.

  According to the configuration of (1), the moving body high-accuracy speed measuring apparatus according to the present invention measures the acceleration and angular velocity of the moving body using the IMU, and calculates the speed by strapdown calculation from the measured acceleration and angular velocity of the moving body. And real-time interpolation speed is calculated based on the calculated speed. Next, the mobile high-accuracy speed measuring device measures the Doppler speed of the mobile body from the Doppler shift amount of the GPS carrier using a GPS receiver, and the difference between the acceleration calculated from the measured Doppler speed and the measured acceleration And a coefficient is calculated based on the calculated difference. Next, the mobile high-accuracy speed measurement device delays the time to use the measured Doppler speed for calculation by the time for calculating the coefficient, and synchronizes the delayed Doppler speed with the fed back real-time interpolation speed. The error amount between the synchronized Doppler speed and the real-time interpolation speed is calculated. Next, the mobile high-accuracy speed measuring device multiplies the calculated error amount by the calculated coefficient, and estimates and calculates an adjustment amount for the real-time interpolation speed from the error amount by multiplying the coefficient by the Kalman filter. Then, the moving body high-accuracy speed measurement device calculates the real-time interpolation speed by combining the speed calculated by the strapdown calculation with the adjustment amount estimated by the Kalman filter.

  That is, the mobile high-accuracy speed measuring device determines whether the acceleration due to the Doppler velocity obtained by using the GPS receiver is good or bad by the acceleration measured by an IMU (Inertial Measurement Unit), and determines the pass / fail determination coefficient. It is calculated by feeding back the real-time interpolation speed calculated based on the speed calculated by the strapdown calculation and multiplying the error amount between the calculated Doppler speed and the fed back real-time interpolation speed by the pass / fail judgment coefficient. The error amount is calculated, the adjustment amount for the real-time interpolation speed is estimated by the Kalman filter from the adjusted error amount, and the adjustment amount estimated by the Kalman filter is merged with the speed calculated by the strapdown operation. Calculate the time interpolation speed. Therefore, the mobile high-accuracy speed measurement device can reduce the noise amount of the Doppler velocity calculated from the GPS receiver by adjusting the error amount input to the Kalman filter, and can calculate the velocity in real time. Therefore, the mobile high-accuracy speed measurement device outputs high-accuracy and high-reliability speed in real time even under the situation where signals from GPS satellites are reflected by trees, buildings, etc. and multipath occurs. Can do.

  (2) A method executed by a mobile high-accuracy speed measuring device that includes an IMU and a GPS receiver and measures the speed of the mobile body, and measures acceleration and angular velocity of the mobile body using the IMU. A step-down navigator step for calculating a real-time interpolation speed from the measured acceleration and angular velocity of the moving body by a strap-down operation; A speed measurement step for measuring speed; a difference between the acceleration calculated from the measured Doppler speed and the measured acceleration; and a quality coefficient calculation step for calculating a coefficient based on the calculated difference; and the coefficient The time for calculating the Doppler speed is delayed by the time for calculating A delay processing step, the delayed Doppler speed, and the real-time interpolation speed fed back from the strapdown navigator step are synchronized, and an error amount between the synchronized Doppler speed and the real-time interpolation speed is calculated. A synchronization processing step to calculate, a pass / fail coefficient multiplication step to multiply the calculated error amount by the calculated coefficient, and an adjustment amount for the real-time interpolation speed from the error amount multiplied by the coefficient by a Kalman filter. A Kalman filter step for performing an estimation calculation, wherein the strapdown navigator step calculates the real-time interpolation speed by merging the adjustment amount estimated by the Kalman filter step with the speed calculated by the strapdown calculation. The way.

  Therefore, as in (1), the method according to (2) is highly accurate and reliable even under the situation where signals from GPS satellites are reflected by trees, buildings, etc. and multipath occurs. The speed can be output in real time.

  The moving body high-accuracy speed measuring apparatus according to the present invention can determine whether the Doppler speed information obtained from the GPS receiver is good or not, and can output a high-accuracy speed in real time. In particular, even when a signal from a GPS satellite is reflected by trees, buildings, etc. and a multipath is generated, the mobile high-accuracy speed measuring device is affected by noise from the Doppler speed obtained from the GPS receiver. It is possible to output the moving body with high accuracy speed in real time. As a result, the moving body high-precision speed measuring device can stably output the high-speed speed of the moving body even on a public road. Furthermore, even when the satellite signal is momentarily interrupted, the mobile high-accuracy speed measuring apparatus can interpolate using the IMU and stably output a high-accuracy speed. In addition, since the mobile high-accuracy speed measuring device is capable of real-time output, there is no need for synchronization processing at the time of simultaneous measurement with other sensors, and secondary processing is also required in vehicle braking tests where output delay is a problem. The original signal of the mobile high-accuracy speed measuring device can be used.

It is a block diagram which shows the structure of the mobile body high precision speed measuring device which is one Embodiment of this invention. It is a figure which shows an example of the hardware constitutions of the mobile body high precision speed measuring device which concerns on one Embodiment of this invention. It is a flowchart which shows the processing content in the moving body high-accuracy speed measuring device which concerns on one Embodiment of this invention. It is a figure which shows the real-time interpolation speed output by the moving body high-accuracy speed measuring device which concerns on one Embodiment of this invention, and the Doppler speed by a GPS receiver. It is a figure which shows the rise of the real-time interpolation speed output by the moving body high-accuracy speed measuring device which concerns on one Embodiment of this invention, and the rise of the Doppler speed output from a GPS receiver. It is a figure which shows the real-time interpolation speed output by the mobile body high precision speed measuring device which concerns on one Embodiment of this invention, the Doppler speed output from a GPS receiver, and the speed output from an optical speed measuring device. . It is a figure which shows the speed of the vehicle which moves on a public road by the Doppler speed from a GPS receiver.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a mobile high-accuracy speed measuring apparatus 10 according to an embodiment of the present invention. The moving body high-accuracy speed measurement device 10 includes an acceleration measurement unit 11, a strapdown navigator unit 12, a speed measurement unit 13, a quality coefficient calculation unit 14, a delay processing unit 15, a synchronization processing unit 16, and a quality coefficient. A multiplication unit 17 and a Kalman filter unit 18 are provided.

  The acceleration measuring unit 11 uses the IMU 102 to measure the acceleration and angular velocity of the moving object. The IMU 102 is composed of a three-axis gyro and a three-direction accelerometer, and obtains a three-dimensional angular velocity and acceleration. The IMU 102 may further include a plurality of sensors in order to improve measurement reliability.

  The strapdown navigator unit 12 (autonomous navigation algorithm) calculates the speed by the strapdown calculation from the acceleration and angular velocity of the moving body measured by the acceleration measurement unit 11, and the calculated speed is estimated and calculated by the Kalman filter unit 18 described later. The real-time interpolation speed is calculated by fusing the adjustment amounts, and the calculated real-time interpolation speed is output and fed back to the Kalman filter unit 18.

  The speed measurement unit 13 uses the GPS receiver 101 to measure the Doppler speed of the moving body from the Doppler shift amount of the GPS carrier wave. For example, when the distance between the GPS receiver 101 and the GPS satellite increases or decreases, the phase of the carrier wave received by the GPS receiver 101 continuously changes, and the frequency decreases or increases. The speed measurement unit 13 acquires the Doppler speed output from the GPS receiver 101 from the amount of change in frequency.

  The pass / fail coefficient calculation unit 14 calculates the difference between the acceleration calculated from the Doppler velocity measured by the speed measurement unit 13 and the acceleration measured by the acceleration measurement unit 11, and based on the calculated difference (in FIG. 1) β) is calculated. For example, the pass / fail coefficient calculation unit 14 converts the acceleration measured by the IMU 102 by a coordinate conversion processing unit (not shown) based on the current posture angle calculated by the strapdown navigator unit 12, and receives the GPS receiver. 101 converts the Doppler velocity output to the acceleration in the same coordinate system. Then, the pass / fail coefficient calculation unit 14 calculates the difference between the acceleration obtained by differentiating the Doppler velocity and the coordinate-converted acceleration, squares the calculated difference, and performs envelope processing on the squared difference. Next, the pass / fail coefficient calculation unit 14 obtains an inverse function of the function indicating the difference after the envelope processing, and calculates a coefficient based on the obtained inverse function. That is, the pass / fail coefficient calculation unit 14 performs a pass determination when it is determined that the Doppler speed does not include noise based on the obtained inverse function, and performs a determination when it is determined that the Doppler speed includes noise. A pass / fail coefficient is obtained by quantifying the judgment. For example, the pass / fail coefficient may be calculated by: pass / fail coefficient = 1−speed fluctuation determination−α × Doppler accuracy index. Here, the speed fluctuation determination is the ratio at which the Doppler speed is determined to include noise, α is a predetermined value, the Doppler speed accuracy index is an information related to the positioning of the GPS satellites, information obtained from the GPS receiver such as the number of observation satellites This is a statistically calculated index based on The pass / fail coefficient calculated in this way is a coefficient for adjusting an error amount input to the Kalman filter unit 18.

  The delay processing unit 15 delays the time for which the Doppler speed measured by the speed measurement unit 13 is used for calculation by the time for which the coefficient is calculated by the pass / fail coefficient calculation unit 14. That is, the delay processing unit 15 delays an operation for calculating an error amount based on the Doppler speed, which will be described later, by a time during which the coefficient is calculated by the pass / fail coefficient calculation unit 14.

  The synchronization processing unit 16 synchronizes the Doppler speed delayed by the delay processing unit 15 with the real-time interpolation speed fed back from the strapdown navigator unit 12, and the synchronized Doppler speed and real-time interpolation speed are The error amount (δx in FIG. 1) is calculated.

  The pass / fail coefficient multiplier 17 multiplies the error amount calculated by the synchronization processor 16 by the coefficient calculated by the pass / fail coefficient calculator 14.

  The Kalman filter unit 18 uses the Kalman filter to estimate and adjust the adjustment amount for the real-time interpolation speed from the error amount multiplied by the coefficient by the pass / fail coefficient multiplying unit 17. For example, the Kalman filter unit 18 calculates the current adjustment amount (filtered estimation value) from the input error amount and the adjustment amount that is estimated and stored one step before, and is an iterative estimator (iterative estimation filter). It is.

  As described above, the mobile high-accuracy speed measuring apparatus 10 multiplies the error amount calculated by synchronizing the Doppler speed measured by the speed measuring unit 13 and the fed back real-time interpolation speed by the pass / fail coefficient of the Doppler speed, The real-time interpolation speed is calculated by fusing the adjustment amount estimated by the Kalman filter unit 18 from the adjusted error amount and the speed calculated by the strapdown calculation from the acceleration and angular velocity measured by the acceleration measurement unit 11. Then, the calculated real-time interpolation speed is output and fed back.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the moving body high-accuracy speed measuring apparatus 10 according to an embodiment of the present invention. The mobile high-accuracy speed measuring apparatus 10 includes a CPU (Central Processing Unit) 1010, a bus line 1005, a communication I / F 1040, a memory 1050, a display 1022, a GPS receiver 101, and an IMU 102.

  The CPU 1010 is a part that controls the mobile high-accuracy speed measuring device 10 in an integrated manner, and by reading and executing various programs stored in the memory 1050 as appropriate, the CPU 1010 cooperates with the hardware described above, and relates to the present invention. Various functions are realized.

  The memory 1050 stores a program that is read and executed as appropriate, and stores various information created by the execution of the program. For example, the memory 1050 stores a real-time interpolation speed fed back by the strapdown navigator unit 12, an adjustment amount estimated by the Kalman filter unit 18, and the like.

  Here, the display unit 1022 displays a calculation processing result by the mobile high-accuracy speed measuring device 10, for example, a calculated real-time interpolation speed, a Doppler speed in the calculation process, and the like, and is a liquid crystal display (LCD). Display devices.

  The communication I / F 1040 is a network adapter that enables the mobile high-accuracy speed measuring apparatus 10 to be connected to a host computer or the like via a dedicated network. The communication I / F 1040 is a connection interface for outputting the calculated real-time interpolation speed to a host computer or the like.

  The GPS receiver 101 includes an antenna and an antenna signal processing circuit necessary for wireless communication. The GPS receiver 101 receives radio waves from a plurality of GPS satellites, calculates a Doppler speed from the received Doppler shift amount of the GPS carrier wave, and outputs the Doppler speed.

  The IMU 102 measures and outputs the acceleration and angular velocity of the moving body. The IMU 102 is an inertial measurement unit (IMU), and detects a three-axis angle (or angular velocity) and acceleration that control motion by a three-axis gyro and a three-direction accelerometer.

  FIG. 3 is a flowchart showing the processing contents in the moving body high-accuracy speed measuring apparatus 10 according to the embodiment of the present invention. Note that this process starts, for example, upon receiving a program start command and ends with a program end command.

  In step S101, the CPU 1010 performs initial setting (initial speed, initial position, initial attitude angle) of the strapdown navigator unit 12, and initial setting of the Kalman filter unit 18 (initialization of an error covariance matrix). Thereafter, the CPU 1010 advances the processing to step S102.

  In step S <b> 102, the CPU 1010 (acceleration measurement unit 11) measures acceleration and angular velocity using the IMU 102. Thereafter, the CPU 1010 advances the processing to step S103.

  In step S103, the CPU 1010 (strap down navigator unit 12) calculates a speed by strapdown calculation from the acceleration and angular velocity measured in step S102, and fuses the adjustment amount from the Kalman filter unit 18 to calculate a real-time interpolation speed. Output and feed back. Thereafter, the CPU 1010 advances the processing to step S104.

  In step S <b> 104, the CPU 1010 (speed measurement unit 13) acquires the Doppler speed output from the GPS receiver 101. More specifically, the CPU 1010 acquires the Doppler speed calculated from the Doppler shift amount of the GPS carrier wave received by the GPS receiver 101. Thereafter, the CPU 1010 advances the processing to step S105.

  In step S105, the CPU 1010 (the pass / fail coefficient calculation unit 14) calculates the pass / fail coefficient from the Doppler speed. More specifically, the CPU 1010 calculates a difference between the acceleration obtained by differentiating the Doppler velocity calculated in step S103 and the acceleration measured by the IMU 102, squares the calculated difference, and performs envelope processing on the squared difference. Then, the CPU 1010 obtains an inverse function of the function indicating the difference after performing the envelope process, and determines that the reliability of the Doppler speed (the Doppler speed does not include noise) based on the obtained inverse function. Then, a pass / fail coefficient (β) indicating the result of the determination for NO) is calculated. Thereafter, the CPU 1010 advances the process to step S106.

  In step S106, the CPU 1010 (delay processing unit 15, synchronization processing unit 16) synchronizes the fed back real-time interpolation speed with the Doppler speed, and calculates an error amount. More specifically, the CPU 1010 delays the calculation for calculating the error amount based on the Doppler speed calculated in Step S104 by the time during which the pass / fail coefficient is calculated in Step S105, and is fed back to the delayed Doppler speed. The error amount (δx) is calculated in synchronization with the real-time interpolation speed. Thereafter, the CPU 1010 shifts the processing to step S107.

  In step S107, the CPU 1010 (the pass / fail coefficient multiplying unit 17) multiplies the error amount by the pass / fail coefficient. More specifically, the CPU 1010 calculates the adjusted error amount (βδx) by multiplying the error amount (δx) calculated in step S106 by the pass / fail coefficient (β) calculated in step S105. Thereafter, the CPU 1010 advances the processing to step S108.

  In step S108, the CPU 1010 (Kalman filter unit 18) estimates and calculates an adjustment amount for the real-time interpolation speed from the adjusted error amount (βδx) using the Kalman filter. Thereafter, the CPU 1010 advances the processing to step S102.

  FIG. 4 is a diagram showing a real-time interpolation speed output by the moving body high-accuracy speed measuring apparatus 10 according to an embodiment of the present invention and a Doppler speed by the GPS receiver 101. FIG. 4A is a graph showing the Doppler velocity by the GPS receiver 101 in a graph in which the vertical axis represents speed and the horizontal axis represents time. Similarly, FIG. 4B is a graph showing the real-time interpolation speed output by the mobile high-accuracy speed measuring device 10 on a graph with the vertical axis representing speed and the horizontal axis representing time.

  As shown in FIG. 4A, when a signal from a GPS satellite is reflected by trees, buildings, etc. and a multipath is generated, the Doppler speed by the GPS receiver 101 includes a speed due to noise due to the multipath. Is output. On the other hand, as shown in FIG. 4B, even if the Doppler velocity by the GPS receiver 101 includes noise due to multipath, the mobile high-precision velocity measuring device 10 reduces the influence of noise and is extremely smooth. The speed of the moving object is output according to the waveform.

  FIG. 5 is a diagram illustrating the rise of the real-time interpolation speed output by the mobile high-accuracy speed measurement device 10 according to the embodiment of the present invention and the rise of the Doppler speed output from the GPS receiver 101. FIG. 5A is a diagram showing a comparison between the speed output by the mobile high-accuracy speed measuring device 10, the Doppler speed by the GPS receiver 101, and the speed obtained by performing low-pass processing of 1 Hz on the Doppler speed. FIG. 5B is an enlarged view of a part of FIG. 5A (a part surrounded by a broken line circle).

  As shown in FIG. 5B, the moving body high-accuracy speed measurement device 10 compares the Doppler speed including noise due to multipath and the speed obtained by removing noise from the Doppler speed including noise due to multipath by low-pass processing. The output speed realizes real-time performance by reducing the output delay due to the calculation for noise removal.

  FIG. 6 shows a real-time interpolation speed output by the mobile high-accuracy speed measurement apparatus 10 according to an embodiment of the present invention, a Doppler speed output from the GPS receiver 101, and a speed output from the optical speed measurement apparatus. FIG. Here, the optical speed measurement device extracts and extracts only the irregular reflection at a specific interval from the irregular pattern on the road surface by a special light receiving element having a comb-like structure with a specific interval (for example, 2.3 mm). A high-accuracy speed calculated by multiplying the count value of the uneven reflection by a specific interval is output.

  As shown in FIG. 6, the moving body high-accuracy speed measuring apparatus 10 reduces the influence of noise in the Doppler speed including noise due to multipath, outputs the speed of the moving body in real time, and the output speed is an optical speed. It is the same as the high-precision speed by the measuring device.

  According to this embodiment, the moving body high-accuracy speed measuring apparatus 10 measures the acceleration and angular velocity of the moving body using the IMU 102, calculates the speed by strapdown calculation from the measured acceleration and angular velocity of the moving body, and calculates A real-time interpolation speed is calculated based on the obtained speed. Next, the moving body high-accuracy speed measuring apparatus 10 measures the Doppler speed of the moving body from the Doppler shift amount of the GPS carrier using the GPS receiver 101, and calculates the acceleration calculated from the measured Doppler speed, And a coefficient is calculated based on the calculated difference. Next, the moving body high-accuracy speed measuring apparatus 10 delays the time to use the measured Doppler speed for calculation by the time for which the coefficient is calculated, and the delayed Doppler speed and the fed back real-time interpolation speed are calculated. Synchronization is performed, and an error amount between the synchronized Doppler speed and the real-time interpolation speed is calculated. Next, the mobile high-accuracy speed measuring apparatus 10 multiplies the calculated error amount by the calculated coefficient, and estimates and calculates an adjustment amount for the real-time interpolation speed from the error amount by multiplying the coefficient by the Kalman filter. The moving body high-accuracy speed measuring device 10 calculates the real-time interpolation speed by combining the speed calculated by the strap-down calculation with the adjustment amount estimated by the Kalman filter, outputs the calculated real-time interpolation speed, and feeds it back. . Therefore, the mobile high-accuracy speed measuring device 10 outputs high-accuracy and high-reliability speed in real time even in a situation where signals from GPS satellites are reflected by trees, buildings, etc. and multipath occurs. be able to.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

DESCRIPTION OF SYMBOLS 10 Mobile body high-accuracy speed measurement apparatus 11 Acceleration measurement part 12 Strapdown navigator part 13 Speed measurement part 14 Pass / fail coefficient calculation part 15 Delay process part 16 Synchronization process part 17 Pass / fail coefficient multiplication part 18 Kalman filter part 101 GPS receiver 102 IMU

Claims (2)

A moving body high-accuracy speed measuring device that measures the speed of a moving body,
Acceleration measuring means for measuring acceleration and angular velocity of the moving body using an IMU;
Strapdown navigator means for calculating a speed by strapdown calculation from the acceleration and angular velocity of the moving body measured by the acceleration measuring means, and calculating a real-time interpolation speed based on the calculated speed;
Speed measuring means for measuring the Doppler speed of the mobile body from the Doppler shift amount of the GPS carrier using a GPS receiver;
A pass / fail coefficient calculating means for calculating a difference between the acceleration calculated from the Doppler velocity measured by the speed measuring means and the acceleration measured by the acceleration measuring means, and calculating a coefficient based on the calculated difference;
A delay processing means for delaying a time to use the Doppler speed measured by the speed measuring means for calculation by a time for the coefficient to be calculated by the pass / fail coefficient calculating means;
The Doppler speed delayed by the delay processing means is synchronized with the real-time interpolation speed fed back from the strapdown navigator means, and an error amount between the synchronized Doppler speed and the real-time interpolation speed is obtained. Synchronization processing means for calculating;
Pass / fail coefficient multiplying means for multiplying the error amount calculated by the synchronization processing means by the coefficient calculated by the pass / fail coefficient calculating means;
Kalman filter means for estimating and calculating an adjustment amount for the real-time interpolation speed from an error amount multiplied by the coefficient by the pass / fail coefficient multiplying means by a Kalman filter;
With
The strap down navigator means calculates the real-time interpolation speed by combining the speed calculated by the strap down calculation and the adjustment amount estimated by the Kalman filter means to calculate the real-time interpolation speed. A method that a mobile high-accuracy speed measurement device that includes an IMU and a GPS receiver and measures the speed of a mobile body executes the method,
An acceleration measurement step of measuring acceleration and angular velocity of the moving body using the IMU;
A strapdown navigator step that calculates a speed by a strapdown calculation from the measured acceleration and angular velocity of the moving body, and calculates a real-time interpolation speed based on the calculated speed;
A speed measurement step of measuring the Doppler speed of the mobile body from the Doppler shift amount of the GPS carrier using the GPS receiver;
A pass / fail coefficient calculation step of calculating a difference between the acceleration calculated from the measured Doppler velocity and the measured acceleration, and calculating a coefficient based on the calculated difference;
A delay processing step of delaying the time to use the Doppler speed for calculation by the time for calculating the coefficient;
Synchronization processing for synchronizing the delayed Doppler speed with the real-time interpolation speed fed back from the strapdown navigator step and calculating an error amount between the synchronized Doppler speed and the real-time interpolation speed Steps,
A pass / fail coefficient multiplication step of multiplying the calculated error amount by the calculated coefficient;
A Kalman filter step for estimating an adjustment amount for the real-time interpolation speed from an error amount multiplied by the coefficient by a Kalman filter,
The strapdown navigator step calculates the real-time interpolation speed by fusing the adjustment amount estimated and calculated by the Kalman filter step with the speed calculated by the strapdown calculation.

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