A method, apparatus, device and storage medium for multipath interference cancellation

Abstract

This invention discloses a multipath interference cancellation method, apparatus, device, and storage medium. It establishes a first expression for the path length of a first reflection path with respect to vertical distance, and a second expression for the path length of a second reflection path with respect to vertical distance. It also establishes a target function for the phase difference between the echo signals of the first and second reflection paths with respect to vertical distance. The method calculates the target vertical distance that makes the target function equal to a preset value. It calculates the position of the target reflection point on the hoistway wall of the second reflection path when the vertical distance between the radar and the reflector is equal to the target vertical distance. It controls the installation of a reflection path disruption device at the target reflection point. During car operation, when the radar is at the target vertical distance, it can only receive the echo signal of the first reflection path, avoiding the problem of echo signals canceling each other out and improving the accuracy of car position measurement.

Description

Technical Field

[0001] This invention relates to radar ranging technology, and more particularly to a method, apparatus, device, and storage medium for multipath interference cancellation. Background Technology

[0002] Radar ranging is a non-contact measurement method. Compared with other elevator car absolute position measurement solutions such as scales, radar solutions have the advantages of simple installation and maintenance and low cost, and are widely used in elevator car position measurement.

[0003] The basic principle of radar ranging is that the radar installed on the top of the elevator car transmits radar signals to the signal reflector installed on the top of the elevator shaft. The radar signals are reflected back to the radar after being reflected by the signal reflector. The radar receives the echo signal from the signal reflector and processes it to achieve distance measurement.

[0004] During radar measurement of the car's position, the radar signal has two paths: one is that the radar signal directly reaches the signal reflector and is reflected back to the radar along the same path; the other is that the radar signal is reflected by the hoistway wall, reaches the signal reflector, and is reflected back to the radar along the same path. If the phase difference between the echo signals of the two paths is 180° or close to 180°, the echo signals of the two paths will cancel each other out, resulting in a decrease in the signal-to-noise ratio of the echo signals, leading to a reduction in measurement accuracy, or even making position measurement impossible. Summary of the Invention

[0005] This invention provides a multipath interference cancellation method, apparatus, device, and storage medium to avoid the problem of echo signals from two different paths canceling each other out, which would reduce measurement accuracy or even make position measurement impossible, thereby improving the accuracy of car position measurement.

[0006] In a first aspect, the present invention provides a multipath interference cancellation method, comprising:

[0007] Using the vertical distance from the radar to the reflector as a variable, a first expression for the path length of the first reflection path and a second expression for the path length of the second reflection path are established with respect to the vertical distance. The first reflection path is the path from the radar signal being emitted by the radar and directly reflected back to the radar by the reflector. The second reflection path is the path from the radar signal being emitted by the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path.

[0008] Based on the first expression and the second expression, establish an objective function for the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance;

[0009] Calculate the target vertical distance that makes the value of the objective function equal to a preset value;

[0010] When the vertical distance between the radar and the reflector is calculated to be the target vertical distance, the second reflection path is located at the target reflection point on the shaft wall;

[0011] The control installation equipment installs a reflection path disruption device at the location of the target reflection point, so that the radar signal cannot propagate along the second reflection path at the target reflection point.

[0012] Optionally, the radar and the reflector are on the same vertical line, and the first expression for the distance of the first reflection path with respect to the vertical distance is:

[0013] S1 = 2D

[0014] The second expression for the distance of the second reflection path with respect to the vertical distance is:

[0015]

[0016] Wherein, S1 is the distance of the first reflection path, S2 is the distance of the second reflection path, D is the vertical distance from the radar to the reflector, and L is the distance from the reflector to the well wall.

[0017] Optionally, the radar and the reflector are not on the same vertical line, and the first expression for the distance of the first reflection path with respect to the vertical distance is:

[0018]

[0019] The second expression for the distance of the second reflection path with respect to the vertical distance is:

[0020]

[0021] Wherein, S1 is the distance of the first reflection path, S2 is the distance of the second reflection path, D is the vertical distance from the radar to the reflector, L is the distance from the reflector to the shaft wall, and R is the distance from the radar to the shaft wall.

[0022] Optionally, establishing an objective function for the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path with respect to the vertical distance, based on the first expression and the second expression, includes:

[0023] Calculate the difference between the second expression and the first expression to obtain the expression for the path difference between the second reflection path and the first reflection path;

[0024] Based on the expression for the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal, the target function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance is determined.

[0025] Optionally, before calculating the target vertical distance that makes the objective function equal to a preset value, the method further includes:

[0026] The vertical distance from the radar to the reflector is excluded if the path difference between the second reflection path and the first reflection path is greater than or equal to the radar's resolution.

[0027] Optionally, before calculating the target vertical distance that makes the objective function equal to a preset value, the method further includes:

[0028] The vertical distance range of the radar reaching the reflector is calculated based on the radar's antenna angle and the distance from the radar to the shaft wall, when the radar signal is reflected by the shaft wall and can be received by the radar.

[0029] Vertical distances outside the stated vertical distance range.

[0030] Optionally, based on the expression for the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal, a target function for determining the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance is determined, including:

[0031] Using the expression for the path difference as the dividend and the wavelength of the radar signal as the divisor, determine the expression for the remainder when the path difference is divided by the wavelength of the radar signal;

[0032] The expression for the remainder is calculated as the quotient of the wavelength of the radar signal, and multiplied by 360° to obtain the target function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance.

[0033] Optionally, the objective function for the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path with respect to the vertical distance is:

[0034]

[0035] in, Let ΔS be the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path, ΔS be the path difference between the second reflection path and the first reflection path, λ be the wavelength of the radar signal, and MOD() be the remainder function.

[0036] Optionally, the radar and the reflector are on the same vertical line, and the location of the target reflection point on the shaft wall of the second reflection path is:

[0037]

[0038] Where d is the vertical distance between the target reflection point on the well wall and the reflector, and D ′ The objective function is set to be equal to the target vertical distance of a preset value.

[0039] Optionally, the radar and the reflector are not on the same vertical line, and the location of the target reflection point on the shaft wall of the second reflection path is:

[0040]

[0041] Where d is the vertical distance between the target reflection point on the well wall and the reflector, and D ′ To ensure that the target function value equals the target vertical distance of the preset value, L is the distance from the reflector to the shaft wall, and R is the distance from the radar to the shaft wall.

[0042] Optionally, the reflection path disruption device is an absorbing material used to absorb the radar signal at the target reflection point, or the reflection path disruption device is a reflector used to reflect the radar signal to a direction other than the reflector.

[0043] Secondly, the present invention also provides a multipath interference cancellation device, comprising:

[0044] The path expression establishment module is used to establish a first expression for the path of the first reflection path with respect to the vertical distance from the radar to the reflector, and a second expression for the path of the second reflection path with respect to the vertical distance, wherein the first reflection path is the path from the radar to the reflector, whereby the radar signal is emitted from the radar and directly reflected back to the radar; the second reflection path is the path from the radar to the elevator shaft wall, reflected to the reflector, and then reflected back to the radar along the same path.

[0045] The objective function establishment module is used to establish an objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance, based on the first expression and the second expression.

[0046] The target vertical distance calculation module is used to calculate the target vertical distance that makes the value of the objective function equal to a preset value;

[0047] The reflection point location calculation module is used to calculate the location of the target reflection point on the shaft wall of the second reflection path when the vertical distance between the radar and the reflector is the target vertical distance;

[0048] The installation control module is used to control the installation equipment to install a reflection path disruption device at the target reflection point, so that the radar signal cannot propagate along the second reflection path at the target reflection point.

[0049] Thirdly, the present invention also provides an electronic device, comprising:

[0050] One or more processors;

[0051] Memory, used to store one or more programs;

[0052] When the one or more programs are executed by the one or more processors, the one or more processors implement the multipath interference cancellation method provided in the first aspect of the present invention.

[0053] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the multipath interference cancellation method provided in the first aspect of the present invention.

[0054] The multipath interference cancellation method provided by this invention uses the vertical distance from the radar to the reflector as a variable. It establishes a first expression for the path length of the first reflection path with respect to the vertical distance, and a second expression for the path length of the second reflection path with respect to the vertical distance. The first reflection path is the path from the radar signal being emitted by the radar and directly reflected back to the radar by the reflector. The second reflection path is the path from the radar signal being emitted by the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path. Based on the first and second expressions, an objective function is established for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance. The objective function is set to equal the target vertical distance. When the vertical distance between the radar and the reflector is equal to the target vertical distance, the position of the target reflection point on the shaft wall of the second reflection path is determined. The control equipment is used to install a reflection path disruption device at the target reflection point, preventing the radar signal from propagating along the second reflection path at the target reflection point. During car operation, when the radar is at the target vertical distance, it can only receive the echo signal from the first reflection path. This avoids the problem of reduced measurement accuracy or even inability to measure position when the phase difference between the echo signals from the two different paths is equal to the preset value, thus improving the accuracy of car position measurement.

[0055] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A flowchart of a multipath interference cancellation method provided in an embodiment of the present invention;

[0058] Figure 2 A schematic diagram of car position measurement provided in an embodiment of the present invention;

[0059] Figure 3 The relationship between the objective function minus 180° and the vertical distance from the radar to the reflector is shown in the graph.

[0060] Figure 4 for Figure 3 The relationship diagram after excluding points corresponding to certain vertical distances;

[0061] Figure 5 This is another schematic diagram of car position measurement provided in an embodiment of the present invention;

[0062] Figure 6 This is a schematic diagram of a multipath interference cancellation device provided in an embodiment of the present invention;

[0063] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0064] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0065] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0066] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0067] Figure 1 This is a flowchart of a multipath interference cancellation method provided in an embodiment of the present invention. This embodiment is applicable to situations where radar receives echo signals from multiple reflection paths when measuring the car position, and these echo signals interfere with each other, leading to reduced measurement accuracy. This method can be executed by the multipath interference cancellation device provided in this embodiment of the present invention. This device can be implemented in software and / or hardware, and is typically configured in electronic devices, such as... Figure 1 As shown, the multipath interference cancellation method specifically includes the following steps:

[0068] S101. Using the vertical distance from the radar to the reflector as a variable, establish a first expression for the path length of the first reflection path with respect to the vertical distance, and a second expression for the path length of the second reflection path with respect to the vertical distance.

[0069] In this embodiment of the invention, the radar can be installed on the top of the elevator car, and the reflector can be installed on the top of the elevator shaft, or the radar can be installed on the top of the shaft, and the reflector can be installed on the top of the car. This embodiment of the invention does not impose any limitations on this. The vertical distance from the radar to the reflector is the distance between the projections of the radar and the reflector on the plumb line, which is also the distance from the top of the car to the top of the shaft (i.e., the position of the car). In this embodiment of the invention, the radar and the reflector can be on the same vertical line or not; this embodiment of the invention does not impose any limitations on this. The radar is a Frequency Modulated Continuous Wave (FMCW) radar. For example, the radar signal frequency f is 60 GHz, the wavelength λ is 5 mm, and the bandwidth is 4 GB.

[0070] In this embodiment of the invention, the first reflection path is the path from which the radar signal is emitted from the radar and directly reflected back to the radar by the reflector; the second reflection path is the path from which the radar signal is emitted from the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path. For example, in this embodiment of the invention, the shaft wall refers to the shaft wall with a hall door installed.

[0071] In this embodiment of the invention, the vertical distance from the radar to the reflector is used as a variable. Based on the principle of reflection and geometric relationships, a first expression for the path length of the first reflection path with respect to the vertical distance and a second expression for the path length of the second reflection path with respect to the vertical distance are established respectively.

[0072] S102. Based on the first and second expressions, establish an objective function for the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance.

[0073] After establishing a first expression for the path length of the first reflection path with respect to the vertical distance, and a second expression for the path length of the second reflection path with respect to the vertical distance, an objective function for the phase difference between the echo signals of the first and second reflection paths with respect to the vertical distance is established based on the first and second expressions.

[0074] For example, from the first and second expressions, we can obtain an expression for the path difference between the second and first reflection paths. From the relationship between the path difference and the phase difference, we can obtain an expression for the phase difference between the echo signals of the first and second reflection paths. In other words, we obtain the objective function of the phase difference between the echo signals of the first and second reflection paths with respect to the vertical distance.

[0075] S103. Calculate the target vertical distance that makes the objective function equal to the preset value.

[0076] After establishing an objective function for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance, the target vertical distance that makes the objective function equal to a preset value is calculated. The preset value can be any value between 170° and 190°, and this embodiment of the invention does not limit it. That is, when the vertical distance from the radar to the reflector is equal to the target vertical distance, the phase difference between the echo signals from the first and second reflection paths is 180° or close to 180°. The echo signals from the two paths will cancel each other out, reducing the signal-to-noise ratio of the echo signals and resulting in reduced accuracy in car position measurement, or even making position measurement impossible. The purpose of this invention is to eliminate the interference between the echo signals from the two paths, thereby improving the accuracy of car position measurement. For example, in a specific embodiment of the invention, the preset value is 180°.

[0077] It should be noted that, in this embodiment of the invention, there are multiple target vertical distances such that the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path is equal to a preset value.

[0078] S104. When the vertical distance between the radar and the reflector is equal to the vertical distance to the target, calculate the position of the target reflection point on the shaft wall of the second reflection path.

[0079] After calculating the target vertical distance that makes the target function equal to the preset value, based on the reflection principle and geometric relationship, the position of the target reflection point on the shaft wall of the second reflection path is calculated when the vertical distance between the radar and the reflector is the target vertical distance, that is, the distance between the target reflection point and the top of the shaft.

[0080] S105. Control the installation equipment to install a reflection path disruption device at the target reflection point, so that the radar signal cannot propagate along the second reflection path at the target reflection point.

[0081] After calculating the location of the target reflection point, the control device installs a reflection path disruption device at the target reflection point, preventing the radar signal from propagating along the second reflection path. The installation device is a controllable automatic device, and this embodiment of the invention is not limited thereto. During car operation, when the radar is at a position perpendicular to the target, the radar can only receive the echo signal from the first reflection path. This avoids the problem of reduced measurement accuracy or even inability to measure position when the phase difference between the echo signals from the two different paths is a preset value, thus improving the accuracy of car position measurement.

[0082] In this embodiment of the invention, the reflection path disruption device can be an absorbing material used to absorb radar signals at the target reflection point, or the reflection path disruption device can be a reflector plate that forms a certain horizontal angle with the plane of the shaft wall, used to reflect radar signals to a direction outside the reflector, so that the radar signals cannot propagate along the second reflection path at the target reflection point.

[0083] The multipath interference cancellation method provided in this invention uses the vertical distance from the radar to the reflector as a variable. It establishes a first expression for the path length of the first reflection path with respect to the vertical distance, and a second expression for the path length of the second reflection path with respect to the vertical distance. The first reflection path is the path from the radar signal being emitted by the radar and directly reflected back to the radar by the reflector. The second reflection path is the path from the radar signal being emitted by the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path. Based on the first and second expressions, an objective function is established for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance. The system calculates the target vertical distance that makes the objective function equal to a preset value. It also calculates the position of the target reflection point on the hoistway wall when the vertical distance between the radar and the reflector is equal to the target vertical distance. The system controls the installation of a reflection path disruption device at the target reflection point, preventing the radar signal from propagating along the second reflection path. During car operation, when the radar is at the target vertical distance, it can only receive the echo signal from the first reflection path. This avoids the problem of reduced measurement accuracy or even inability to measure position when the phase difference between the echo signals from the two different paths is equal to a preset value, thus improving the accuracy of car position measurement.

[0084] To enable those skilled in the art to more clearly understand the technical solution of this application, the solution of the present invention will be described exemplarily below with reference to specific examples.

[0085] Figure 2 This is a schematic diagram of car position measurement provided in an embodiment of the present invention, as shown below. Figure 2 As shown, in this embodiment of the invention, a radar is installed on the top of the elevator car, and a reflector is installed on the top of the elevator shaft. The radar and the reflector are on the same vertical line. The first reflection path is the path from which the radar signal is emitted from the radar and directly reflected back to the radar by the reflector. The second reflection path is the path from which the radar signal is emitted from the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path.

[0086] The first expression for the distance of the first reflection path with respect to the vertical distance is:

[0087] S1 = 2D

[0088] According to the Pythagorean theorem, the second expression for the distance of the second reflection path with respect to the vertical distance is:

[0089]

[0090] Wherein, S1 is the distance of the first reflection path, S2 is the distance of the second reflection path, D is the vertical distance from the radar to the reflector, and L is the distance from the reflector to the shaft wall. In this embodiment of the invention, L is the distance from the reflector to the shaft wall where the hall door is installed.

[0091] After establishing a first expression for the path length of the first reflection path with respect to the vertical distance, and a second expression for the path length of the second reflection path with respect to the vertical distance, an objective function for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance is established based on the first and second expressions. For example, the process of establishing the objective function is as follows:

[0092] 1. Calculate the difference between the second expression and the first expression to obtain the expression for the path difference between the second reflection path and the first reflection path.

[0093] The expression for the path difference between the second reflection path and the first reflection path is:

[0094]

[0095] Where ΔS is the path difference between the second reflection path and the first reflection path.

[0096] 2. Based on the expression for the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal, determine the objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance.

[0097] From the relationship between path difference and phase difference, we can obtain an expression for the phase difference between the echo signals of the first reflection path and the echo signals of the second reflection path, that is, we can obtain the objective function of the phase difference between the echo signals of the first reflection path and the echo signals of the second reflection path with respect to the vertical distance.

[0098] For example, using the expression for the path difference as the dividend and the wavelength of the radar signal as the divisor, determine the expression for the remainder when the path difference is divided by the wavelength of the radar signal. Calculate the quotient of the remainder expression and the wavelength of the radar signal, and multiply by 360° to obtain the objective function of the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance. For example, the objective function of the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance is as follows:

[0099]

[0100] in, Let λ be the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path, ΔS be the path difference between the second reflection path and the first reflection path, λ be the wavelength of the radar signal, and MOD() be the remainder function.

[0101] After establishing an objective function for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance, a target vertical distance is calculated that makes the objective function equal to a preset value. The preset value can be any value between 170° and 190°, and this embodiment of the invention does not limit it. That is, when the vertical distance from the radar to the reflector is equal to the target vertical distance, the phase difference between the echo signals from the first and second reflection paths is 180° or close to 180°, and the echo signals from the two paths will cancel each other out. For example, in a specific embodiment of the invention, the preset value is 180°.

[0102] In some embodiments of the present invention, for ease of calculation, the expression of the objective function is subtracted by 180° to obtain a new objective function:

[0103]

[0104] The calculation of the vertical distance to the target that makes the objective function equal to 180° is transformed into the calculation of the vertical distance to the target that makes the new objective function equal to 0, that is, finding the zero point of the new objective function.

[0105] Figure 3 The graph showing the relationship between the objective function minus 180° and the vertical distance from the radar to the reflector is shown below. Figure 3 As shown by curve a, there are multiple points that make the new objective function equal to or close to 0, and the x-coordinates of these points are the vertical distances to the objective.

[0106] Considering that when the path difference between only two different paths is less than the radar's resolution, the echo signals from the two paths will merge on the spectrum, making them indistinguishable to the radar, i.e., multipath interference occurs, in some embodiments of the present invention, to improve computational efficiency, when calculating the target vertical distance that makes the objective function equal to a preset value, the vertical distance from the radar to the reflector that makes the path difference between the second reflection path and the first reflection path greater than or equal to the radar's resolution is excluded. For example, for a radar with a frequency f of 60 GHz, a wavelength λ of 5 mm, and a bandwidth of 4 GB, its resolution is 37.5 mm.

[0107] Considering the influence of the antenna angle α, not all radar signals reflected from target reflection points can be received by the radar. Therefore, to improve computational efficiency, in this embodiment of the invention, the vertical distance range from the radar to the reflector when the radar signal is reflected by the well wall and can be received by the radar is calculated based on the radar antenna angle and the distance from the radar to the well wall. This range is... Where R is the distance from the radar to the shaft wall, and H is the total height of the shaft. Vertical distances excluding those in the vertical range are excluded.

[0108] Figure 4 for Figure 3 The relationship diagram after excluding points corresponding to certain vertical distances, such as... Figure 4 As shown in curve a, after excluding the vertical distance from the radar to the reflector that makes the path difference between the second reflection path and the first reflection path greater than or equal to the radar resolution, and excluding the vertical distance outside the range of the vertical distance from the radar to the reflector when the radar signal is reflected by the shaft wall and can be received by the radar, the amount of calculation is greatly reduced.

[0109] When the vertical distance between the radar and the reflector is equal to the vertical distance between the target and the radar, the position of the target reflection point on the shaft wall along the second reflection path is:

[0110]

[0111] Where d is the vertical distance between the target reflection point on the well wall and the reflector on the second reflection path, D ′ To ensure the objective function value equals the preset target vertical distance, as mentioned earlier, the positions of multiple target reflection points can be obtained.

[0112] After obtaining the location of the target reflection point, the control installation equipment installs a reflection path disruption device at the target reflection point, preventing the radar signal from propagating along the second reflection path at the target reflection point. In this embodiment of the invention, the reflection path disruption device can be an absorbing material used to absorb the radar signal at the target reflection point, or it can be a reflector plate forming a certain horizontal angle with the shaft wall plane to reflect the radar signal in a direction other than the reflector, thereby preventing the radar signal from propagating along the second reflection path at the target reflection point.

[0113] Figure 5 Another schematic diagram for measuring the car position provided in an embodiment of the present invention is shown below. Figure 5As shown, in this embodiment of the invention, the radar is installed on the top of the elevator car, and the reflector is installed on the top of the elevator shaft. The radar and the reflector are not on the same vertical line. The first reflection path is the path where the radar signal is emitted from the radar and directly reflected back to the radar by the reflector. The second reflection path is the path where the radar signal is emitted from the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path.

[0114] The first expression for the distance of the first reflection path with respect to the vertical distance is:

[0115]

[0116] The second expression for the distance of the second reflection path with respect to the vertical distance is:

[0117]

[0118] Wherein, S1 is the distance of the first reflection path, S2 is the distance of the second reflection path, D is the vertical distance from the radar to the reflector, L is the distance from the reflector to the shaft wall, and R is the distance from the radar to the shaft wall. The shaft wall described in this invention is a shaft wall with a hall door installed.

[0119] After establishing a first expression for the path length of the first reflection path with respect to the vertical distance, and a second expression for the path length of the second reflection path with respect to the vertical distance, an objective function for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance is established based on the first and second expressions. For example, the process of establishing the objective function is as follows:

[0120] 1. Calculate the difference between the second expression and the first expression to obtain the expression for the path difference between the second reflection path and the first reflection path.

[0121] The expression for the path difference between the second reflection path and the first reflection path is:

[0122]

[0123] Where ΔS is the path difference between the second reflection path and the first reflection path.

[0124] 2. Based on the expression for the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal, determine the objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance.

[0125] From the relationship between path difference and phase difference, we can obtain an expression for the phase difference between the echo signals of the first reflection path and the echo signals of the second reflection path, that is, we can obtain the objective function of the phase difference between the echo signals of the first reflection path and the echo signals of the second reflection path with respect to the vertical distance.

[0126] For example, using the expression for the path difference as the dividend and the wavelength of the radar signal as the divisor, determine the expression for the remainder when the path difference is divided by the wavelength of the radar signal. Calculate the quotient of the remainder expression and the wavelength of the radar signal, and multiply by 360° to obtain the objective function of the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance. For example, the objective function of the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance is as follows:

[0127]

[0128] in, Let λ be the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path, ΔS be the path difference between the second reflection path and the first reflection path, λ be the wavelength of the radar signal, and MOD() be the remainder function.

[0129] After establishing an objective function for the phase difference between the echo signals from the first and second reflection paths with respect to the vertical distance, a target vertical distance is calculated that makes the objective function equal to a preset value. The preset value can be any value between 170° and 190°, and this embodiment of the invention does not limit it. That is, when the vertical distance from the radar to the reflector is equal to the target vertical distance, the phase difference between the echo signals from the first and second reflection paths is 180° or close to 180°, and the echo signals from the two paths will cancel each other out. For example, in a specific embodiment of the invention, the preset value is 180°.

[0130] In some embodiments of the present invention, for ease of calculation, the expression of the objective function is subtracted by 180° to obtain a new objective function:

[0131]

[0132] The calculation of the vertical distance to the target that makes the objective function equal to 180° is transformed into the calculation of the vertical distance to the target that makes the new objective function equal to 0, that is, finding the zero point of the new objective function.

[0133] like Figure 3 As shown by curve b, there are multiple points that make the new objective function equal to or close to 0, and the x-coordinates of these points are the vertical distances to the objective.

[0134] Considering that when the path difference between only two different paths is less than the radar's resolution, the echo signals from the two paths will merge on the spectrum, making them indistinguishable to the radar, i.e., multipath interference occurs, in some embodiments of the present invention, to improve computational efficiency, when calculating the target vertical distance that makes the objective function equal to a preset value, the vertical distance from the radar to the reflector that makes the path difference between the second reflection path and the first reflection path greater than or equal to the radar's resolution is excluded. For example, for a radar with a frequency f of 60 GHz, a wavelength λ of 5 mm, and a bandwidth of 4 GB, its resolution is 37.5 mm.

[0135] Considering the influence of the antenna angle α, not all radar signals reflected from target reflection points can be received by the radar. Therefore, to improve computational efficiency, in this embodiment of the invention, the vertical distance range from the radar to the reflector when the radar signal is reflected by the well wall and can be received by the radar is calculated based on the radar antenna angle and the distance from the radar to the well wall. This range is... Where R is the distance from the radar to the shaft wall, and H is the total height of the shaft. Vertical distances excluding those in the vertical range are excluded.

[0136] like Figure 4 As shown in curve b, after excluding the vertical distance from the radar to the reflector that makes the path difference between the second reflection path and the first reflection path greater than or equal to the radar resolution, and excluding the vertical distance outside the range of the vertical distance from the radar to the reflector when the radar signal is reflected by the shaft wall and can be received by the radar, the amount of calculation is greatly reduced.

[0137] When the vertical distance between the radar and the reflector is equal to the vertical distance to the target, based on the property of similar triangles, triangle EFG is similar to triangle ABC. Let AB = D′, the position of the target reflection point on the shaft wall of the second reflection path is:

[0138]

[0139] Where d is the vertical distance between the target reflection point on the shaft wall and the reflector (i.e., the length of line segment EF) of the second reflection path, D′ is the vertical distance of the target that makes the target function equal to the preset value, L is the distance from the reflector to the shaft wall (i.e., the length of line segment GF), and R is the distance from the radar to the shaft wall (i.e., the length of line segment BF).

[0140] After obtaining the location of the target reflection point, the control installation equipment installs a reflection path disruption device at the target reflection point, preventing the radar signal from propagating along the second reflection path at the target reflection point. In this embodiment of the invention, the reflection path disruption device can be an absorbing material used to absorb the radar signal at the target reflection point, or it can be a reflector plate forming a certain horizontal angle with the shaft wall plane to reflect the radar signal in a direction other than the reflector, thereby preventing the radar signal from propagating along the second reflection path at the target reflection point.

[0141] In some embodiments of the present invention, two reflectors may be used to measure the position of the car, one of which (referred to as the first reflector) is on the same vertical line as the radar, and the other (referred to as the second reflector) is not on the same vertical line as the radar. (Refer to...) Figure 4 Based on the objective function of phase difference, it can be seen that for the first reflector, the location of multipath interference is only related to D and L, where D is the independent variable and L is determined during radar installation; for the second reflector, the location of multipath interference is only related to D, L, and R, where D is the independent variable and R is determined during radar installation. Therefore, by adjusting the distance from the second reflector to the shaft wall, it can be ensured that one of the two reflectors is always unaffected by multipath interference, thereby improving the accuracy of car position measurement.

[0142] Figure 6 This is a schematic diagram of a multipath interference cancellation device provided in an embodiment of the present invention, as shown below. Figure 6 As shown, the multipath interference cancellation device includes:

[0143] The path expression establishment module 201 is used to establish a first expression for the path of the first reflection path with respect to the vertical distance from the radar to the reflector, and a second expression for the path of the second reflection path with respect to the vertical distance, wherein the first reflection path is the path from the radar to the reflector, whereby the radar signal is emitted from the radar and directly reflected back to the radar; the second reflection path is the path from the radar to the elevator shaft wall, reflected to the reflector, and reflected back to the radar along the same path.

[0144] The objective function establishment module 202 is used to establish an objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance, based on the first expression and the second expression.

[0145] The target vertical distance calculation module 203 is used to calculate the target vertical distance that makes the value of the objective function equal to a preset value;

[0146] The reflection point location calculation module 204 is used to calculate the location of the target reflection point on the well wall of the second reflection path when the vertical distance between the radar and the reflector is the target vertical distance;

[0147] The installation control module 205 is used to control the installation equipment to install a reflection path disruption device at the target reflection point, so that the radar signal cannot propagate along the second reflection path at the target reflection point.

[0148] In some embodiments of the present invention, the radar and the reflector are located on the same vertical line, and the first expression for the distance of the first reflection path with respect to the vertical distance is:

[0149] S1 = 2D

[0150] The second expression for the distance of the second reflection path with respect to the vertical distance is:

[0151]

[0152] Wherein, S1 is the distance of the first reflection path, S2 is the distance of the second reflection path, D is the vertical distance from the radar to the reflector, and L is the distance from the reflector to the well wall.

[0153] In some embodiments of the present invention, the radar and the reflector are not on the same vertical line, and the first expression for the distance of the first reflection path with respect to the vertical distance is:

[0154]

[0155] The second expression for the distance of the second reflection path with respect to the vertical distance is:

[0156]

[0157] Wherein, S1 is the distance of the first reflection path, S2 is the distance of the second reflection path, D is the vertical distance from the radar to the reflector, L is the distance from the reflector to the shaft wall, and R is the distance from the radar to the shaft wall.

[0158] In some embodiments of the present invention, the objective function establishment module 202 includes:

[0159] The path difference calculation submodule is used to calculate the difference between the second expression and the first expression to obtain an expression for the path difference between the second reflection path and the first reflection path;

[0160] The objective function determination submodule is used to determine the objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance, based on the expression of the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal.

[0161] In some embodiments of the present invention, the multipath interference cancellation device further includes:

[0162] The first exclusion module is used to exclude vertical distances from the radar to the reflector that make the path difference between the second reflection path and the first reflection path greater than or equal to the radar's resolution before calculating the target vertical distance that makes the value of the objective function equal to a preset value.

[0163] In some embodiments of the present invention, the multipath interference cancellation device further includes:

[0164] The range calculation module is used to calculate, before calculating the target vertical distance that makes the value of the objective function equal to a preset value, the vertical distance range of the radar reaching the reflector when the radar signal is reflected by the well wall and can be received by the radar, based on the antenna angle of the radar and the distance from the radar to the well wall;

[0165] The first exclusion module is used to exclude vertical distances outside the vertical distance range.

[0166] In some embodiments of the present invention, the objective function determination submodule includes:

[0167] The remainder unit is used to determine the expression for the remainder when the path difference is divided by the wavelength of the radar signal, using the expression for the path difference as the dividend and the wavelength of the radar signal as the divisor.

[0168] The calculation unit is used to calculate the quotient of the expression of the remainder and the wavelength of the radar signal, and multiply it by 360° to obtain the target function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance.

[0169] In some embodiments of the present invention, the objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance is:

[0170]

[0171] in, Let ΔS be the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path, ΔS be the path difference between the second reflection path and the first reflection path, λ be the wavelength of the radar signal, and MOD() be the remainder function.

[0172] In some embodiments of the present invention, the radar and the reflector are on the same vertical line, and the position of the second reflection path at the target reflection point on the shaft wall is:

[0173]

[0174] Where d is the vertical distance between the target reflection point on the well wall and the reflector of the second reflection path, and D′ is the target vertical distance that makes the value of the objective function equal to the preset value.

[0175] In some embodiments of the present invention, the radar and the reflector are not on the same vertical line, and the position of the target reflection point on the shaft wall of the second reflection path is:

[0176]

[0177] Where d is the vertical distance between the target reflection point on the shaft wall and the reflector of the second reflection path, D′ is the target vertical distance that makes the value of the target function equal to the preset value, L is the distance from the reflector to the shaft wall, and R is the distance from the radar to the shaft wall.

[0178] In some embodiments of the present invention, the reflection path disruption device is an absorbing material used to absorb the radar signal of the target reflection point, or the reflection path disruption device is a reflector used to reflect the radar signal to a direction other than the reflector.

[0179] The multipath interference cancellation device described above can perform the multipath interference cancellation method provided in the foregoing embodiments of the present invention, and has the corresponding functional modules and beneficial effects for performing the multipath interference cancellation method.

[0180] Figure 7 This is a schematic diagram of an electronic device provided for an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0181] like Figure 7As shown, the electronic device includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded into the RAM 13 from storage unit 18. The RAM 13 can also store various programs and data required for the operation of the electronic device. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0182] Multiple components in the electronic device are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, optical disk, etc.; and a communication unit 19, such as a network card, modem, wireless transceiver, etc. The communication unit 19 allows the electronic device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0183] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as multipath interference cancellation methods.

[0184] In some embodiments, the multipath interference cancellation method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on an electronic device via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the multipath interference cancellation method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the multipath interference cancellation method by any other suitable means (e.g., by means of firmware).

[0185] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0186] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0187] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0188] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0189] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0190] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0191] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the multipath interference cancellation method provided in any embodiment of this application.

[0192] In implementing the computer program product, computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0193] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0194] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for eliminating multipath interference, characterized in that, include: Using the vertical distance from the radar to the reflector as a variable, a first expression for the path length of the first reflection path and a second expression for the path length of the second reflection path are established with respect to the vertical distance. The first reflection path is the path from the radar signal being emitted by the radar and directly reflected back to the radar by the reflector. The second reflection path is the path from the radar signal being emitted by the radar, reflected by the elevator shaft wall to the reflector, and then reflected back to the radar along the same path. Based on the first expression and the second expression, establish an objective function for the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance; Calculate the target vertical distance that makes the value of the objective function equal to a preset value; When the vertical distance between the radar and the reflector is calculated to be the target vertical distance, the second reflection path is located at the target reflection point on the shaft wall; The control and installation equipment installs a reflection path disruption device at the location of the target reflection point, so that the radar signal cannot propagate along the second reflection path at the target reflection point; The objective function for the phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path with respect to the vertical distance is: in, The phase difference between the echo signal from the first reflection path and the echo signal from the second reflection path. This represents the path difference between the second reflection path and the first reflection path. The wavelength of the radar signal is... For the remainder function; The radar and the reflector are on the same vertical line, and the location of the target reflection point on the shaft wall of the second reflection path is: in, The vertical distance between the target reflection point on the shaft wall and the reflector is the second reflection path. To make the value of the objective function equal to the target vertical distance of a preset value; The radar and the reflector are not on the same vertical line, and the location of the target reflection point on the shaft wall of the second reflection path is: in, The vertical distance between the target reflection point on the shaft wall and the reflector is the second reflection path. To make the value of the objective function equal to the target vertical distance of the preset value, The distance from the reflector to the wellbore wall. The distance from the radar to the wellbore wall.

2. The multipath interference cancellation method according to claim 1, characterized in that, The radar and the reflector are on the same vertical line, and the first expression for the distance of the first reflection path with respect to the vertical distance is: The second expression for the distance of the second reflection path with respect to the vertical distance is: in, The distance of the first reflection path. The distance of the second reflection path. The vertical distance from the radar to the reflector. The distance from the reflector to the well wall.

3. The multipath interference cancellation method according to claim 1, characterized in that, The radar and the reflector are not on the same vertical line, and the first expression for the distance of the first reflection path with respect to the vertical distance is: The second expression for the distance of the second reflection path with respect to the vertical distance is: in, The distance of the first reflection path. The distance of the second reflection path. The vertical distance from the radar to the reflector. The distance from the reflector to the wellbore wall. The distance from the radar to the wellbore wall.

4. The multipath interference cancellation method according to any one of claims 1-3, characterized in that, Based on the first expression and the second expression, an objective function is established for the phase difference between the echo signals from the first reflection path and the second reflection path with respect to the vertical distance, including: Calculate the difference between the second expression and the first expression to obtain the expression for the path difference between the second reflection path and the first reflection path; Based on the expression for the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal, the target function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance is determined.

5. The multipath interference cancellation method according to claim 4, characterized in that, Before calculating the target vertical distance that makes the objective function equal to a preset value, the method further includes: The vertical distance from the radar to the reflector is excluded if the path difference between the second reflection path and the first reflection path is greater than or equal to the radar's resolution.

6. The multipath interference cancellation method according to claim 4, characterized in that, Before calculating the target vertical distance that makes the objective function equal to a preset value, the method further includes: The vertical distance range of the radar reaching the reflector is calculated based on the radar's antenna angle and the distance from the radar to the shaft wall, when the radar signal is reflected by the shaft wall and can be received by the radar. Vertical distances outside the stated vertical distance range.

7. The multipath interference cancellation method according to claim 4, characterized in that, Based on the expression for the path difference between the second reflection path and the first reflection path and the wavelength of the radar signal, the target function for determining the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance is determined, including: Using the expression for the path difference as the dividend and the wavelength of the radar signal as the divisor, determine the expression for the remainder when the path difference is divided by the wavelength of the radar signal; The expression for the remainder is calculated as the quotient of the wavelength of the radar signal, and multiplied by 360° to obtain the target function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance.

8. The multipath interference cancellation method according to any one of claims 1-3 and 5-7, characterized in that, The reflection path disruption device is an absorbing material used to absorb radar signals from the target reflection point, or the reflection path disruption device is a reflector used to reflect the radar signals to a direction other than the reflector.

9. A multipath interference cancellation device, characterized in that, For performing the multipath interference cancellation method according to any one of claims 1-8, comprising: The path expression establishment module is used to establish a first expression for the path of the first reflection path with respect to the vertical distance from the radar to the reflector, and a second expression for the path of the second reflection path with respect to the vertical distance, wherein the first reflection path is the path from the radar to the reflector, whereby the radar signal is emitted from the radar and directly reflected back to the radar; the second reflection path is the path from the radar to the elevator shaft wall, reflected to the reflector, and then reflected back to the radar along the same path. The objective function establishment module is used to establish an objective function of the phase difference between the echo signal of the first reflection path and the echo signal of the second reflection path with respect to the vertical distance, based on the first expression and the second expression. The target vertical distance calculation module is used to calculate the target vertical distance that makes the value of the objective function equal to a preset value; The reflection point location calculation module is used to calculate the location of the target reflection point on the shaft wall of the second reflection path when the vertical distance between the radar and the reflector is the target vertical distance; The installation control module is used to control the installation equipment to install a reflection path disruption device at the target reflection point, so that the radar signal cannot propagate along the second reflection path at the target reflection point.

10. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the multipath interference cancellation method as described in any one of claims 1-8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the multipath interference cancellation method as described in any one of claims 1-8.

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