Dead reckoning method under sidewalk gait of pedestrian

Abstract

The invention provides a dead reckoning method under a pedestrian side walking gait, and the method comprises the steps: binding a micro inertial sensor to the waist, and collecting the three-axis acceleration and three-axis angular velocity data of a pedestrian in a motion state; the mean value and the variance of the lateral acceleration of the pedestrian are calculated, whether the pedestrian is in a lateral walking gait or not is judged, and the lateral acceleration is the acceleration in the horizontal plane and in the direction perpendicular to the forward direction of the body; if the robot is in the side walking gait, calculating north and east position increments of a single step to obtain a side walking deviation angle; calculating the real movement direction of side walking, and carrying out dead reckoning by using the obtained real movement direction; if not, dead reckoning is directly carried out. According to the method, the side walking gait is judged according to the acceleration data characteristics, the side walking direction is calculated according to the position increment, and high-precision dead reckoning of the pedestrian in the side walking gait is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of pedestrian navigation, and in particular relates to a dead reckoning method for pedestrians in a sideways gait. Background Art

[0002] Pedestrian dead reckoning divides pedestrians' steps into individual steps, estimates the length and direction of each step, and thus calculates the position to obtain real-time positioning results.

[0003] The heading used in pedestrian dead reckoning is the heading solved by the inertial sensor. However, when walking sideways, the pedestrian's movement direction is inconsistent with the solved heading, resulting in position calculation errors. Summary of the invention

[0004] In view of the technical problem in the prior art that the movement direction of pedestrians in a side-walking state is inconsistent with the calculated heading, resulting in incorrect position calculation, the present invention provides a dead reckoning method for pedestrians in a side-walking gait, which uses acceleration data characteristics to judge the side-walking gait and uses position increments to calculate the side-walking direction, thereby achieving high-precision dead reckoning of pedestrians in a side-walking gait.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0006] The present invention provides a dead reckoning method for pedestrians in sideways gait, comprising the following steps:

[0007] The micro-inertial sensor is tied to the waist to collect the three-axis acceleration and three-axis angular velocity data of the pedestrian in motion;

[0008] Calculate the mean and variance of the pedestrian's lateral acceleration to determine whether the pedestrian is in a sideways gait, wherein the lateral acceleration is the acceleration in the horizontal plane and perpendicular to the forward direction of the body;

[0009] If it is in a side-walking gait, calculate the north and east position increments of a single step to obtain the side-walking deviation angle;

[0010] Calculate the true direction of movement of the sideways walk, and use the obtained true direction of movement to perform dead reckoning;

[0011] If not in side-walk gait, proceed directly to dead reckoning.

[0012] Furthermore, the calculating of the mean and variance of the pedestrian's lateral acceleration to determine whether the pedestrian is in a lateral walking gait specifically includes the following steps:

[0013] Calculate the mean and variance of the pedestrian's lateral acceleration within one step:

[0014]

[0015] in, δacc They represent the mean and variance of the pedestrian’s lateral acceleration, t i-1 ,t i are the start time and end time of a step respectively, t is the pedestrian's lateral acceleration at time t, and m is the number of acceleration samples in one step;

[0016] When satisfied and |δ acc When |≥γ2, the pedestrian is in a side-walking gait, otherwise the pedestrian is in a normal gait, where γ1 and γ2 are the first threshold and the second threshold for side-walking discrimination, respectively.

[0017] Furthermore, the method for calculating the north and east position increments of a single step to obtain the sideways deviation angle is as follows:

[0018]

[0019] Among them, ΔS N , ΔS E are the position increments in the north and east directions within one step respectively, and θ is the lateral deviation angle.

[0020] Furthermore, the method further comprises the step of calculating a heading dynamic error compensation amount, and the heading dynamic error compensation amount calculation method is as follows:

[0021]

[0022] in, is the mean lateral acceleration of the kth pedestrian, g is the acceleration due to gravity, φ k ,φ k-1 are the headings of the pedestrian at the kth step and the k-1th step respectively;

[0023] The actual movement direction is:

[0024] φ=90°-θ-Δθ

[0025] Among them, θ is the sideways deviation angle, and Δθ is the heading dynamic error compensation.

[0026] Furthermore, the dead reckoning method is as follows:

[0027]

[0028] Among them, S N (t i ), S E (t i ) are t i The north and east positions of pedestrians at each moment, S N (t i-1 ), S E (ti-1 ) are t i-1 The north and east positions of the pedestrian at each moment, l is the empirical single-step length when walking sideways, and φ is the actual movement direction.

[0029] The beneficial effects of the present invention compared with the prior art are as follows:

[0030] The present invention proposes a dead reckoning method for pedestrians in a sideways gait. The method uses acceleration data features to judge the sideways gait and uses position increments to calculate the sideways direction, thereby achieving high-precision dead reckoning for pedestrians in a sideways gait.

[0031] In addition, the present invention adopts a heading dynamic error compensation amount to correct the change in the sideways walking direction caused by the twisting or shaking of the waist and other actions, thereby improving the accuracy of dead reckoning. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A flowchart of a dead reckoning method for a pedestrian sideways gait provided in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0034] Specific embodiments of the present invention are described in detail below. In the following description, for the purpose of explanation and not limitation, specific details are set forth to help fully understand the present invention. However, it will be apparent to those skilled in the art that the present invention may also be practiced in other embodiments that depart from these specific details.

[0035] It should be noted that in order to avoid obscuring the present invention due to unnecessary details, only the device structure and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0036] The present invention belongs to the field of pedestrian navigation based on micro-inertial sensors, and relates to a method for dead reckoning of pedestrians in a sideways gait. Pedestrian dead reckoning divides the pedestrian's single steps, estimates the step length and direction of each step, and then performs position reckoning to obtain real-time positioning results. In order to solve the problem that the direction of movement of pedestrians in a sideways gait is inconsistent with the solved heading, the sideways gait is judged by using the acceleration data characteristics, and the direction of movement is estimated by the position increments in the north and east directions, which can improve the accuracy of pedestrian dead reckoning. The present invention is particularly suitable for solving the engineering application needs of pedestrian dead reckoning in complex motion states.

[0037] In order to realize the dead reckoning under the side-walking gait, the present invention discriminates the side-walking state based on the acceleration mean and variance characteristics, calculates the true movement direction of the side-walking using the north and east position increments obtained by the inertial sensor, and performs position reckoning based on the true movement direction. The specific dead reckoning method is as follows:

[0038] The micro-inertial sensor is tied to the waist to collect the three-axis acceleration and three-axis angular velocity data of the pedestrian in motion;

[0039] Calculate the mean and variance of the pedestrian's lateral acceleration to determine whether the pedestrian is in a sideways gait, wherein the lateral acceleration is the acceleration in the horizontal plane and perpendicular to the forward direction of the body;

[0040] If it is in a side-walking gait, calculate the north and east position increments of a single step to obtain the side-walking deviation angle;

[0041] Calculate the true direction of movement of the sideways walk, and use the obtained true direction of movement to perform dead reckoning;

[0042] If not in side-walk gait, proceed directly to dead reckoning.

[0043] Based on the above processing, the present invention greatly improves the dead reckoning accuracy of pedestrians in special gaits such as sideways walking.

[0044] The technical solution of the present invention is described in detail below in conjunction with a specific embodiment.

[0045] In order to improve the dead reckoning accuracy of pedestrians in complex gaits such as sideways walking, this embodiment proposes a dead reckoning method for pedestrians in sideways walking gait, which specifically includes the following steps:

[0046] 1. Collect inertial data and perform lateral gait detection

[0047] The micro-inertial sensor is tied to the waist to collect the three-axis acceleration and three-axis angular velocity data of pedestrians in normal walking, sideways walking and other motion states. The original inertial data is segmented to obtain the start and end time of each step, and the mean and variance of the pedestrian's lateral acceleration within one step are calculated:

[0048]

[0049] in, δ acc They represent the mean and variance of the pedestrian’s lateral acceleration, t i-1 ,t i are the start time and end time of a step respectively, t is the lateral acceleration of the pedestrian at time t, and m is the number of acceleration samples in one step.

[0050] It should be noted that the three-axis acceleration in the present invention is the acceleration of the X, Y, and Z axes of the micro-inertial sensor carrier coordinate system; the three-axis angular velocity is the angular velocity of the X, Y, and Z axes of the micro-inertial sensor carrier coordinate system; at the same time, the X, Y, and Z axes are also one of the forward, lateral, and vertical directions of the human body according to different installation methods. In the present invention, the lateral acceleration is the acceleration in the horizontal direction perpendicular to the forward direction of the body, and the acceleration in the corresponding direction is obtained according to the construction of the carrier coordinate system.

[0051] In the sideways walking gait, the amplitude of the pedestrian's lateral acceleration is larger than that of normal walking, and the data fluctuation is more intense. Therefore, the corresponding mean and variance should be larger than that of normal walking. Based on this, the sideways walking gait can be judged as follows:

[0052]

[0053] δ acc |≥γ2

[0054] Among them, γ1 and γ2 are the side-walking discrimination thresholds, which are related to the noise characteristics of the sensor and the physiological characteristics of the pedestrian, such as height and weight. They are engineering experience values. Every time the inertial sensor or personnel is replaced, the two discrimination thresholds need to be calibrated in advance.

[0055] When satisfied and |δ acc When |≥γ2, the pedestrian is in a sideways gait, otherwise the pedestrian is in a normal gait and dead reckoning is performed directly.

[0056] 2. Sideways direction calculation

[0057] After determining that the pedestrian is in a sideways gait, the sideways direction is further calculated. First, the inertial navigation system is used to calculate the position increments of the north and east directions of the geographic system within one step, and then the sideways deviation angle is calculated:

[0058]

[0059] Among them, ΔS N , ΔS E are the position increments in the north and east directions within one step respectively, and θ is the lateral deviation angle.

[0060] When pedestrians walk sideways, their waists twist or shake, which causes the walking direction to change further based on the deviation angle. Therefore, it is necessary to calculate the heading dynamic error compensation. The heading of the pedestrian at the kth step is defined as φ k , the heading of the k-1th step is φ k-1 , then the heading dynamic error compensation Δθ can be expressed as:

[0061]

[0062] in, is the mean lateral acceleration of the kth pedestrian, and g is the acceleration due to gravity. It represents the intensity of the pedestrian's movement when walking sideways. The larger the value, the greater the movement amplitude and the greater the heading error that needs to be compensated.

[0063] Based on the sideways deviation angle and heading dynamic error compensation, the real movement direction in the geographic coordinate system during sideways walking is calculated:

[0064] φ=90°-θ-Δθ

[0065] 3. Sideways dead reckoning

[0066] After obtaining the true direction of movement of the sideways walk, the dead reckoning is performed based on the empirical step length of the single step during sideways walk:

[0067]

[0068] Among them, S N (t i ) and S E (t i ) are t i The north and east positions of the pedestrian at each moment, and l is the empirical single-step length when walking sideways.

[0069] The present invention proposes a dead reckoning method for pedestrians in a sideways gait. The method uses acceleration data features to judge the sideways gait and uses position increments to calculate the sideways direction, thereby achieving high-precision dead reckoning for pedestrians in a sideways gait.

[0070] In addition, the present invention adopts a heading dynamic error compensation amount to correct the change in the sideways walking direction caused by the twisting or shaking of the waist and other actions, thereby improving the accuracy of dead reckoning.

[0071] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or used in place of features in other embodiments.

[0072] It should be emphasized that the term "include / comprises" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0073] The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended that the embodiments of the invention be limited to the exact construction and operation illustrated and described, but rather all suitable modifications and equivalents falling within the scope thereof are intended to be covered.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0075] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A dead reckoning method for pedestrian sideways gait, characterized in that: The steps include: The micro-inertial sensor is tied to the waist to collect the three-axis acceleration and three-axis angular velocity data of the pedestrian in motion; Calculate the mean and variance of the pedestrian's lateral acceleration to determine whether the pedestrian is in a sideways gait, wherein the lateral acceleration is the acceleration in the horizontal plane and perpendicular to the forward direction of the body; If it is in a side-walking gait, calculate the north and east position increments of a single step to obtain the side-walking deviation angle; Calculate the true direction of movement of the sideways walk, and use the obtained true direction of movement to perform dead reckoning; If not in side-walk gait, proceed directly to dead reckoning.

2. The method according to claim 1, characterized in that The step of calculating the mean and variance of the pedestrian's lateral acceleration and determining whether the pedestrian is in a lateral walking gait specifically includes the following steps: Calculate the mean and variance of the pedestrian's lateral acceleration within one step: in, δ acc They represent the mean and variance of the pedestrian’s lateral acceleration, t i-1 ,t i are the start time and end time of a step respectively, t is the pedestrian's lateral acceleration at time t, and m is the number of acceleration samples in one step; When satisfied and |δ acc When |≥γ2, the pedestrian is in a side-walking gait, otherwise the pedestrian is in a normal gait, where γ1 and γ2 are the first threshold and the second threshold for side-walking discrimination, respectively.

3. The method according to claim 1, characterized in that The method for calculating the north and east position increments of a single step and obtaining the sideways deviation angle is as follows: Among them, ΔS N , ΔS E are the position increments in the north and east directions within one step respectively, and θ is the lateral deviation angle.

4. The method according to claim 3, characterized in that The method further comprises the step of calculating a heading dynamic error compensation amount, and the heading dynamic error compensation amount calculation method is as follows: in, is the mean lateral acceleration of the kth pedestrian, g is the acceleration due to gravity, φ k ,φ k-1 are the headings of the pedestrian at the kth step and the k-1th step respectively; The actual movement direction is: φ=90°-θ-Δθ Among them, θ is the sideways deviation angle, and Δθ is the heading dynamic error compensation.

5. The method according to claim 1, characterized in that The dead reckoning method is as follows: Among them, S N (t i ), S E (t i ) are t i The north and east positions of pedestrians at each moment, S N (t i-1 ), S E (t i-1 ) are t i-1 The north and east positions of the pedestrian at each moment, l is the empirical single-step length when walking sideways, and φ is the actual movement direction.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: The processor executes the computer program to implement the method described in any one of claims 1 to 5.

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