CN107091639B - A Method for Determining the Total Length of Trajectories Based on Adaptive Average Window Length - Google Patents

Abstract

The invention discloses a method for determining the total length of a trajectory based on an adaptive average window length, comprising: S1: acquiring zero-speed state information of a target unit; S2: calculating each segment according to the start time and end time corresponding to each segment of static state information The average window length of the static state; S3: get the average value according to the average window length of each static state and the trajectory of each static state; S4: calculate the length of each walking trajectory according to the average value of each static state trajectory ; S5: Summing the lengths of all walking trajectories to obtain the total length of the walking trajectories. The present invention has the following advantages: the total length of the trajectories output by various foot strapdown inertial navigation systems can be accurately calculated, and the versatility is strong; under the premise of not changing the foot strapdown inertial navigation system, it increases Adaptive average window length selection method module based on zero-speed correction static state; the algorithm has low complexity and is easy to implement in engineering.

Description

A Method for Determining the Total Length of Trajectories Based on Adaptive Average Window Length

technical field

The invention relates to the field of indoor positioning, in particular to a method for determining the total length of a track based on an adaptive average window length.

Background technique

With the rapid development of wireless communication technology and the gradual popularization of mobile intelligent terminals, location-based service (Location-based Service, LBS) has become an important part of the intelligent society. In addition to personnel positioning in emergency situations, LBS has been widely used in military defense, transportation, modern logistics, geodetic mapping and other fields, and is currently developing towards a more colorful and innovative mobile location service with huge market potential. , such as location-based social, advertising, mobile search lights. These innovative location-based services are based on the mobile Internet and require real-time access to precise geographic location information of users in both indoor and outdoor spaces.

Inertial navigation system has been applied in many positioning fields due to its advantages of high precision, autonomy, and little influence from the outside world. For example, in outdoor scenarios, the inertial navigation system can assist GNSS to improve its positioning accuracy, and can make up for the shortcomings of GNSS with signal blind spots. In indoor positioning, MEMS inertial measurement elements can be installed on multiple parts of a person's feet, waist, head, etc., to realize human positioning and navigation.

An important output in the navigation system is the total length of the trajectory. However, due to the high sampling rate of the MEMS inertial measurement element, the actual output positioning trajectory is the trajectory of the foot. Traditionally, when calculating the total length of the trajectory, the positioning results for each fixed period of time are averaged. However, the traditional method will bring two problems. One is that different average window lengths will lead to different total trajectory lengths; the other is that the gait cycle intercepted each time with a fixed window length is different, and it cannot guarantee that a complete gait can be averaged. calculate.

Contents of the invention

The present invention aims to solve at least one of the above-mentioned technical problems.

For this reason, the object of the present invention is to propose a method for determining the total length of the track based on the adaptive average window length, which can accurately calculate the total length of the track.

In order to achieve the above object, the embodiment of the present invention discloses a method for determining the total length of the trajectory based on the adaptive average window length, which includes the following steps: S1: Obtain the zero-speed state information of the target unit, wherein the zero-speed state information Including static state information and motion state information; S2: According to the start time and end time corresponding to each piece of static state information, and then calculate the average window length of each static state; S3: According to the average window length of each static state Length, the trajectory of each section of the stationary state obtain the average value of the trajectory of each section of the stationary state; S4: carry out differential calculations according to the average value of each section of the static state trajectory to obtain the length of each section of the walking trajectory; S5: for all The lengths of the walking trajectories are summed to obtain the total length of the walking trajectories.

Further, the zero-speed state information of the target unit is obtained through a measuring element arranged on the target unit.

Further, according to the value of the zero-speed correction, static state information and motion state information are distinguished.

Further, the average value of each static state trajectory is calculated according to the following formula:

Among them, trajsmooth(k) is the average value of the trajectory corresponding to the k-th static state, winlen(k) represents the average window length of the k-th static state, and traj _k is the trajectory corresponding to the k-th static state.

Further, the length of each walking track is calculated according to the following formula:

Among them, trajlen(k) is the length of segment k in the total walking length, and trajsmooth _x and trajsmooth _y belong to the X and Y components of trajsmooth.

According to the method for determining the total track length based on the adaptive average window length of the embodiment of the present invention, the total track length can be accurately calculated for the positioning tracks output by various foot strapdown inertial navigation systems, and has strong versatility; On the premise of the foot strapdown inertial navigation system, an adaptive average window length selection method module based on zero-speed correction static state is added; the algorithm has low complexity and is easy to implement in engineering.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

FIG. 1 is a flowchart of a method for determining the total length of a track based on an adaptive average window length according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

These and other aspects of embodiments of the invention will become apparent with reference to the following description and drawings. In these descriptions and drawings, some specific implementations of the embodiments of the present invention are specifically disclosed to represent some ways of implementing the principles of the embodiments of the present invention, but it should be understood that the scope of the embodiments of the present invention is not limited by this limit. On the contrary, the embodiments of the present invention include all changes, modifications and equivalents coming within the spirit and scope of the appended claims.

The present invention is described below in conjunction with accompanying drawing.

FIG. 1 is a flowchart of a method for determining the total length of a track based on an adaptive average window length according to an embodiment of the present invention. As shown in Figure 1, the method for determining the total length of the track based on the adaptive average window length according to the embodiment of the present invention includes the following steps:

S1: Obtain the zero-speed status information of the target unit. Wherein, the zero-speed state information includes static state information and motion state information.

In one embodiment of the present invention, the zero-speed state information of the target unit is obtained through a measuring element arranged on the target unit. The measurement element can be a micro-electromechanical inertial measurement element, which is installed on multiple parts of a person's feet, waist, head, etc., to realize the positioning and navigation of a person.

S2: Calculate the average window length of each static state according to the start time and end time corresponding to each static state information.

In an embodiment of the present invention, static state information and motion state information are distinguished according to the value of the zero speed correction.

Specifically, the zero-speed state information includes two states: static state and motion state. When ZUPT=1, it is a static state, and when ZUPT=0, it is a motion state. The part of the zero-speed state information ZUPT=1 is extracted. The start point of the k-th static state is judged as still _k (start), and the end point of the k-th static state is judged as still _k (end). After extracting the start point and end point of the k-th static state, calculate the length of the average window of this static state:

winlen(k)=still _k (end)-still _k (start)

Among them, winlen(k) represents the average window length of the kth static state.

S3: According to the average window length of each static state and the trajectory of each static state, the average value of each static state trajectory is obtained.

In one embodiment of the present invention, the average value of each section of static state trajectory is calculated according to the following formula:

Among them, trajsmooth(k) is the average value of the trajectory corresponding to the k-th static state, and traj _k is the trajectory corresponding to the k-th static state.

S4: Calculate the difference according to the average value of each static state trajectory to obtain the length of each walking trajectory.

In one embodiment of the present invention, calculate the length of each section of walking trajectory according to the following formula:

Among them, trajlen(k) is the length of segment k in the total walking length, and trajsmooth _x and trajsmooth _y belong to the X and Y components of trajsmooth.

S5: Summing the lengths of all the walking trajectories to obtain the total length of the walking trajectories.

Specifically, the total length of the trajectory dis is obtained by summing all trajlen by the following formula:

dis=∑trajlen(k)

Table 1 shows the results of processing data for a period of time in an example by applying the method for determining the total length of a track based on an adaptive average window length according to an embodiment of the present invention. The fixed average window length processing and the adaptive average window length processing based on the zero-speed correction static state are respectively performed on this piece of actual data. The fixed window length processing selects five typical cases of 1 sampling point, 123 sampling points, 246 sampling points, 369 sampling points and 512 sampling points. It can be seen from Table 1 that the method proposed by the present invention can avoid the randomness in calculating the total length of the track.

Table 1

In addition, other components and functions of the method for determining the total track length based on the adaptive average window length in the embodiment of the present invention are known to those skilled in the art, and will not be repeated in order to reduce redundancy.

In the description of this specification, descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (3)

1. A method for determining the total length of a track based on an adaptive average window length, characterized in that, comprising the following steps: S1: Obtain the zero-speed state information of the target unit, wherein the zero-speed state information includes static state information and motion state information; S2: Calculate the average window length of each static state according to the start time and end time corresponding to each static state information; S3: Obtain the average value of each segment of the static state trajectory according to the average window length of each segment of the static state and the trajectory of each segment of the static state; S4: Perform differential calculation according to the average value of each static state trajectory to obtain the length of each walking trajectory; S5: sum the lengths of all the walking trajectories to obtain the total length of the walking trajectories; Among them, the average value of each static state trajectory is calculated according to the following formula: trajsmooth(k) is the average value of the trajectory corresponding to the k-th static state, winlen(k) represents the average window length of the k-th static state, and traj _k is the trajectory corresponding to the k-th static state; Calculate the length of each walking trajectory according to the following formula: trajlen(k) is the length of segment k in the total walking length, trajsmooth _x and trajsmooth _y belong to the X and Y components of trajsmooth. 2. The method for determining the total length of a track based on an adaptive average window length according to claim 1, wherein the zero-speed state information of the target unit is obtained through a measuring element arranged on the target unit. 3. The method for determining the total length of the track based on the adaptive average window length according to claim 2, characterized in that, according to the value of the zero-speed correction, the static state information and the motion state information are distinguished.