A radio frequency antenna radiometric distance measuring instrument and method

Abstract

The embodiment of the specification provides a radio frequency antenna radiation distance measuring instrument and a measuring method. The measuring instrument comprises a beacon assembly, a slide rail, a first supporting arm, a second supporting arm, a power source and a controller. The beacon assembly comprises a beacon capable of detecting radio frequency signals emitted by a measured radio frequency antenna. The first supporting arm and the second supporting arm are respectively configured to be arranged between parallel first and second rails. The slide rail is configured to be arranged between the first supporting arm and the second supporting arm. The beacon assembly is configured to be in sliding connection with the slide rail. The power source is configured to be in transmission connection with the beacon assembly, thereby driving the beacon assembly to move along the slide rail. The controller is configured to be in signal connection with the power source and the beacon respectively, thereby controlling the power source to drive the beacon assembly to move and receiving an output signal of the beacon. The length of the slide rail is not more than half of the maximum value of the radiation distances of two or more measured radio frequency antennas.

Description

Cross-referencing

[0001] This application claims priority to Chinese application No. 202510212978.2, filed on February 26, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This manual relates to the field of train positioning and radio frequency testing technology, and in particular to an instrument and method for measuring the radiation distance of a radio frequency antenna. Background Technology

[0003] In rail transit safety control and traffic management, accurately obtaining train positioning information is a core element in ensuring train safety, improving operational efficiency, and achieving intelligent dispatching. Modern train positioning systems are complex systems integrating multiple technologies, typically employing complementary and cross-validating positioning methods to ensure the continuity, accuracy, and high reliability of train positioning.

[0004] Absolute positioning is one of the core positioning technologies in train positioning systems. It obtains the absolute position of the train by detecting pre-set known position devices along the track. The working principle of absolute positioning is as follows: ground transponders are installed at specific points on the track, and an onboard query device is configured at the train end. This onboard query device integrates a query antenna, which is generally located at the bottom of the train (such as under the locomotive). When the train passes the ground transponder, the onboard query device transmits a radio frequency signal of a specific frequency (such as 4.5MHz, 27MHz, or 900MHz) through its query antenna located at the bottom of the train to activate the ground transponder. The activated ground transponder then transmits its pre-stored programmed data (such as a unique identifier ID, absolute position coordinates, track gradient, speed limit information, etc.) back to the query antenna, which is then used by the onboard query device to calculate the current absolute position information of the train.

[0005] To obtain the absolute position information of a train in a timely and accurate manner during operation, it is essential to ensure a high degree of consistency between the actual identification window and the designed identification window. The identification window refers to the spatial range within which the query antenna can identify the ground transponder. The identification window can be equivalently represented by the spatial range covered by the radio frequency signal transmitted by the query antenna. In actual testing and operational scenarios, the identification window can be simplified to the distance range (also known as the length range) of the area covered by the radio frequency signal transmitted by the query antenna along the track laying direction. The actual identification window is this distance range obtained through actual testing, while the designed identification window is the theoretically designed distance range. However, in actual production and operation scenarios, due to system errors, the actual identification window of the train often deviates from the designed identification window.

[0006] In view of this, embodiments of this specification provide a radio frequency antenna radiation distance measuring instrument and method to achieve accurate measurement of the actual identification window of a train. Summary of the Invention

[0007] This specification provides one or more embodiments of a radio frequency antenna radiation distance measuring instrument, comprising: a beacon assembly, a slide rail, a first arm, a second arm, a power source, and a controller; the beacon assembly includes a beacon capable of detecting radio frequency signals emitted by the radio frequency antenna under test; the first arm and the second arm are respectively configured to span between parallel first and second tracks; the slide rail is configured to span between the first arm and the second arm; the beacon assembly is configured to be slidably connected to the slide rail; the power source is configured to be driveably connected to the beacon assembly, thereby driving the beacon assembly to move along the slide rail; the controller is configured to be signal-connected to the power source and the beacon, thereby controlling the power source to drive the beacon assembly to move and to receive the output signal of the beacon; the length of the slide rail does not exceed half of the maximum value of the radiation distances of two or more radio frequency antennas under test.

[0008] In some embodiments, the length of the slide rail is 0.75m.

[0009] In some embodiments, the lengths of the first arm and the second arm are adjustable.

[0010] In some embodiments, when the slide rail spans between the first support arm and the second support arm, the distance between the slide rail and the first track and the second track is adjustable.

[0011] In some embodiments, the first support arm includes a first support arm segment and a second support arm segment, the second support arm includes a third support arm segment and a fourth support arm segment, and the first support arm segment, the second support arm segment, the third support arm segment and the fourth support arm segment are all telescopic rods; support arm mounting tubes are respectively provided at both ends of the slide rail; one end of the first support arm segment and one end of the second support arm segment are respectively configured to be inserted into the two ends of the support arm mounting tube at one end of the slide rail, thereby connecting to form the first support arm; one end of the third support arm segment and one end of the fourth support arm segment are respectively configured to be inserted into the two ends of the support arm mounting tube at the other end of the slide rail, thereby connecting to form the second support arm.

[0012] In some embodiments, the beacon assembly further includes a mounting plate and a slider; the beacon is disposed on the upper surface of the mounting plate; the mounting plate is rotatably connected to the slider, and the mounting plate is rotatable relative to the slider in a plane parallel to the upper surface; the slider is configured to be slidably connected to the slide rail.

[0013] In some embodiments, the mounting plate is rectangular, the beacon is disposed on one short side of the mounting plate, and the connection between the mounting plate and the slider is located on the other short side of the mounting plate.

[0014] In some embodiments, the instrument further includes a control host configured to have a signal connection with the controller; the controller is configured to control the power source to drive the beacon assembly to move based on motion commands from the control host and to transmit output signals from the beacon to the control host.

[0015] In some embodiments, the control host includes one or more control components, and the control host is configured to generate the motion command in response to a user's triggering operation on the one or more control components.

[0016] This specification also provides one or more embodiments of a measurement method based on the radio frequency antenna radiation distance measuring instrument described in any of the above embodiments, comprising: installing the measuring instrument on a first track and a second track below the radio frequency antenna of the vehicle-mounted interrogator being measured; adjusting the position of the beacon on the vertical line connecting the first track and the second track and the deflection angle of the beacon relative to the slide rail based on the installation method of the ground transponder corresponding to the vehicle-mounted interrogator on the track; determining the nominal value of the radiation distance of the radio frequency antenna; and selecting a measurement procedure corresponding to the nominal value of the radiation distance to measure the radiation distance of the radio frequency antenna.

[0017] In some embodiments, when the nominal radiation distance does not exceed the length of the slide rail, the measurement process includes: acquiring the electromagnetic wave signal received by the beacon at a preset frequency, and analyzing the electromagnetic wave signal to determine whether it includes the target radio frequency signal emitted by the antenna under test; controlling the beacon component to move to the middle position of the slide rail and then continuing to move towards one end of the slide rail; when the beacon component continues to move towards the one end of the slide rail, and the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, determining the first position information of the beacon component, and controlling the beacon component to move in the opposite direction on the slide rail; when the beacon component moves in the opposite direction, and the electromagnetic wave signal changes again from including the target radio frequency signal to not including the target radio frequency signal, determining the second position information of the beacon component; and determining the radiation distance of the radio frequency antenna under test based on the first position information and the second position information.

[0018] In some embodiments, when the beacon assembly continues to move toward one end of the slide rail and reaches that end, the electromagnetic wave signal still includes the target radio frequency signal. Then: the mounting plate is adjusted so that its long side is parallel to the slide rail, and the beacon faces outward from the one end of the slide rail, so that the electromagnetic wave signal does not include the target radio frequency signal; the beacon assembly is controlled to move in the opposite direction; when the beacon assembly moves in the opposite direction, and the electromagnetic wave signal changes from not including the target radio frequency signal to including the target radio frequency signal, the first position information is determined.

[0019] In some embodiments, when the beacon component moves in the reverse direction and reaches the other end of the slide rail, if the electromagnetic wave signal still includes the target radio frequency signal, then: adjust the mounting plate so that the long side of the mounting plate is parallel to the slide rail and the beacon faces the outside of the other end of the slide rail so that the electromagnetic wave signal does not include the target radio frequency signal; control the beacon component to move in the reverse direction again; when the beacon component moves in the reverse direction again and the electromagnetic wave signal changes from not including the target radio frequency signal to including the target radio frequency signal, determine the second position information.

[0020] In some embodiments, when the nominal radiation distance is greater than the slide rail length but less than or equal to twice the slide rail length, the measurement process includes: acquiring the electromagnetic wave signal received by the beacon at a preset frequency, analyzing the electromagnetic wave signal, and determining whether it includes the target radio frequency signal emitted by the measured antenna, and calculating the intensity of the target radio frequency signal when it is included; controlling the beacon assembly to move on the slide rail with the movement range covering the entire slide rail; determining a reference position based on the position information of the beacon assembly when the intensity of the target radio frequency signal is at its maximum value, determining first position information based on the reference position, and controlling the beacon assembly to move from the reference position towards one end of the slide rail; when the During the movement of the beacon component from the reference position toward one end of the slide rail, if the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, then the second position information of the beacon component is determined; if the electromagnetic wave signal does not change from including the target radio frequency signal to not including the target radio frequency signal during the movement of the beacon component from the reference position toward one end of the slide rail, then the beacon component is controlled to move in the opposite direction; if the beacon component moves in the opposite direction and the electromagnetic wave signal changes from not including the target radio frequency signal to including the target radio frequency signal, then the second position information of the beacon component is determined; based on the first position information and the second position information, the radiation distance of the measured radio frequency antenna is determined.

[0021] In some embodiments, if the electromagnetic wave signal includes the target radio frequency signal when the beacon component is at any position on the slide rail, the mounting plate is adjusted so that the long side of the mounting plate is parallel to the slide rail, and the measurement procedure corresponding to the nominal value of the radiation distance is re-executed.

[0022] In some embodiments, determining the radiation distance of the measured radio frequency antenna based on the first location information and the second location information includes: determining the displacement value of the beacon component based on the first location information and the second location information; and determining the radiation distance based on the displacement value and the offset, wherein the offset reflects the distance between the mapped position of the beacon on the long side of the mounting plate and the mapped position of the connection portion on the long side of the mounting plate.

[0023] In some embodiments, the preset frequency is not less than twice the frequency of the target radio frequency signal.

[0024] In some embodiments, the nominal value of the radiation distance is 0.75m or 1.5m. Attached Figure Description

[0025] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein: Figure 1 This is a schematic diagram of a radio frequency antenna radiation distance measuring instrument according to some embodiments of this specification; Figure 2A This is a schematic diagram of the first arm according to some embodiments of this specification; Figure 2B This is a schematic diagram of the second arm according to some embodiments of this specification; Figure 3 This is a partial schematic diagram of a beacon component according to some embodiments of this specification; Figure 4 This is an exemplary flowchart of a measurement method for a radio frequency antenna radiation distance measuring instrument according to some embodiments of this specification; Figure 5 This is an exemplary flowchart illustrating the determination of the radiation distance of a measured radio frequency antenna according to some embodiments of this specification; Figure 6 This is an exemplary flowchart illustrating the determination of the radiation distance of a measured radio frequency antenna according to other embodiments of this specification. Detailed Implementation

[0026] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0027] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0028] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0029] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0030] Figure 1 This is a schematic diagram of a radio frequency antenna radiation distance measuring instrument according to some embodiments of this specification.

[0031] In some embodiments, such as Figure 1 As shown, the radio frequency antenna radiation distance measuring instrument 100 includes a beacon assembly 110, a slide rail 120, a first arm 130, a second arm 140, a power source (not shown in the figure), and a controller 150, etc.

[0032] The beacon assembly 110 includes a beacon and a beacon support.

[0033] A beacon is an electronic component used to receive radio frequency (RF) signals emitted by the RF antenna under test. In some embodiments, the beacon may be mounted on a beacon bracket. In some embodiments, the beacon can convert the received RF signal into an electrical signal and output it to the controller, serving as the core sensing element for the instrument to detect RF signals. In some embodiments, the beacon may be a ground transponder or a component of the RF signal receiving section of a ground transponder.

[0034] A beacon bracket is a support member used to mount and secure a beacon. In some embodiments, the beacon bracket can slide along the slide rail 120. For example, the beacon bracket can be as follows: Figure 1 The X and / or Y directions shown slide along the slide rail 120.

[0035] The slide rail 120 refers to a track structure used to guide the beacon assembly to move in a straight line. In some embodiments, the beacon assembly 110 is configured to be slidably connected to the slide rail 120. Further details regarding the slidable connection between the beacon assembly 110 and the slide rail 120 can be found in [link to relevant documentation]. Figure 2A and Figure 2B .

[0036] In some embodiments, the slide rail 120 is configured to span between the first arm 130 and the second arm 140.

[0037] In some embodiments, the length of the slide rail 120 does not exceed half of the maximum value of the radiation distances of the two or more radio frequency antennas under test.

[0038] The radio frequency antenna under test refers to the query antenna or radio frequency antenna of the vehicle-mounted query device whose radiation distance is being measured. Radiation distance refers to the effective spatial range within which the radio frequency signal emitted by the antenna under test can be effectively detected and identified by a beacon. Radiation distance can also be referred to as the identification window of the query antenna or radio frequency antenna.

[0039] In some embodiments, the RF antenna radiation distance measuring instrument 100 can be applied to measure the radiation distance of multiple RF antennas under test, and the length of the slide rail 120 does not exceed half of the maximum value among the radiation distances of the multiple RF antennas under test. For example, the RF antenna radiation distance measuring instrument 100 can measure three RF antennas under test. The radiation distances of the three RF antennas under test are 1.0m, 1.2m, and 1.5m, respectively. The maximum radiation distance is 1.5m, and half of the maximum value is 0.75m. The length of the slide rail 120 does not exceed half of the maximum value among the radiation distances of the three RF antennas under test, that is, the length of the slide rail 120 does not exceed 0.75m.

[0040] In some embodiments, the length of the slide rail 120 is between 0.75m and 1.5m. In some embodiments, the length of the slide rail 120 is between 0.75m and 1.0m. In some embodiments, the length of the slide rail 120 is 0.75m.

[0041] In some embodiments of this specification, by setting the length of the slide rail, a larger range of radiation distance measurements (such as 0.75m-1.5m range, or even greater than 1.5m range) can be achieved with a shorter beacon component movement distance, which helps to reduce the size of the measuring instrument.

[0042] The first arm 130 and the second arm 140 refer to the support members used to span between the first track 161 and the second track 162. For example... Figure 1 As shown, the first arm 130 and the second arm 140 are respectively straddled between the first track 161 and the second track 162, and are arranged in parallel. The first track 161 and the second track 162 are two parallel traffic tracks. The first track 161 and the second track 162 are the carriers of the radio frequency antenna radiation distance measuring instrument 100.

[0043] In some embodiments, the first arm 130 and the second arm 140 are detachably connected to a track (such as the first track 161 and the second track 162). For example, the first arm 130 and the second arm 140 can be snapped into the track. Further details regarding the connection method between the first arm 130 and the second arm 140 and the track can be found in [reference needed]. Figure 2A and Figure 2B .

[0044] A power source refers to a drive component that provides power for the movement of the beacon assembly along the slide rail 120. In some embodiments, the power source may include a stepper motor. In some embodiments, the power source may be part of a controller 150. In some embodiments, the power source may be a separate component. In some embodiments, the power source is configured to be drive-connected to the beacon assembly, thereby driving the beacon assembly to move along the slide rail. For example, the power source may be drive-connected to the beacon bracket via a ball screw. Exemplarily, the shaft of the stepper motor is fixedly connected to the screw of the ball screw via a coupling, the screw of the ball screw being arranged parallel to the slide rail 120, and the beacon bracket being fixedly connected to a nut fitted onto the screw. When the motor rotates, the ball screw converts the rotation into linear motion, thereby pushing the beacon bracket to move along the slide rail 120.

[0045] Controller 150 refers to a control unit used to control the operation of the power source and receive the beacon output signal. In some embodiments, controller 150 is configured to be connected to the power source and the beacon signal respectively, thereby controlling the power source to drive the beacon assembly 110 to move and to receive the beacon output signal.

[0046] In some embodiments, the radio frequency antenna radiation distance measuring instrument 100 further includes a control host 170. The control host 170 is configured to have a signal connection with the controller 150. The signal connection refers to the connection method that enables bidirectional information transmission between the control host 170 and the controller 150. For example, the signal connection includes both wired and wireless connections.

[0047] The control host 170 refers to an external operating device used to send motion commands to the controller 150 and receive beacon signals for display or processing. In some embodiments, the operating voltage of the control host 170 is DC24V or AC220V. In some embodiments, the control host 170 can be powered by a battery or directly connected to AC power. For example, in the field where power supply is inconvenient, the control host 170 can be powered by a battery to adapt to different working environments.

[0048] In some embodiments, the controller 150 is configured to control the movement of the beacon assembly 110 driven by the power source based on motion commands from the control host 170 and to transmit the beacon's output signal to the control host 170 in the future.

[0049] In some embodiments of this specification, a control host is introduced as a human-machine interaction and data processing center, enabling users to control the measurement process through remote commands, while centrally displaying signal status and location information, facilitating real-time judgment of radiation distance boundaries and reducing on-site operational complexity.

[0050] In some embodiments, the control host 170 includes one or more control components, which are used to generate motion commands in response to user triggering operations on one or more control components. In some embodiments, the control host 170 may generate corresponding motion commands based on the user triggering of a control component and transmit them to the controller 150 to control the movement state of the beacon component 110.

[0051] A control component refers to a user interaction component installed on the control host 170. The control component is an operational unit that implements different motion control functions of the beacon component 110. Different control components correspond to different motion states of the beacon component 110 (such as acceleration, deceleration, jogging, and linkage). Exemplary control components include a first direction control component, a second direction control component, an acceleration control component, a deceleration control component, a jogging control component, and a linkage control component.

[0052] The first direction control component can control the beacon component 110 to move along a first direction. After the user triggers an operation on the first direction control component (such as clicking, pressing, turning, etc.), the control host 170 generates a first motion command instructing the beacon component 110 to move along the first direction. After receiving the first motion command, the controller 150 controls the power source to drive the beacon component 110 to move along the first direction. The first direction is a preset movement direction of the beacon component 110. For example, the first direction can be as follows: Figure 1 The X direction is shown.

[0053] The second direction control component can control the beacon component 110 to move along a second direction. After the user triggers the second direction control component, the control host 170 generates a second movement command instructing the beacon component 110 to move along the second direction. After receiving the second movement command, the controller 150 controls the power source to drive the beacon component 110 to move along the second direction. The second direction is a preset movement direction of the beacon component 110. For example, the second direction can be as follows: Figure 1 The Y-direction is shown. The first direction is opposite to the second direction.

[0054] The acceleration control component can control the beacon component 110 to accelerate. After the user triggers the acceleration control component, the control host 170 generates an acceleration motion command instructing the beacon component 110 to accelerate. After receiving the acceleration motion command, the controller 150 controls the power source to drive the beacon component 110 to accelerate.

[0055] The deceleration control component can control the beacon component 110 to decelerate. After the user triggers the deceleration control component, the control host 170 generates a deceleration motion command instructing the beacon component 110 to decelerate. After receiving the deceleration motion command, the controller 150 controls the power source to drive the beacon component 110 to decelerate.

[0056] The jog control component can control the beacon component 110 to move a preset distance (e.g., 5mm, 1cm, etc.). Each time the user triggers the jog control component, the control host 170 generates a jog motion command instructing the beacon component 110 to move the preset distance. Upon receiving the jog motion command, the controller 150 controls the power source to drive the beacon component 110 to move the preset distance. That is, each time the user triggers the jog control component, the beacon component 110 moves the preset distance.

[0057] The linkage control component can control the beacon component 110 to move continuously and / or stop. After the user triggers the linkage control component, the control host 170 generates a motion command instructing the beacon component 110 to move continuously. When the user triggers the linkage control component again, the control host 170 generates a command instructing the beacon component 110 to stop.

[0058] In some embodiments, the control host 170 can also receive radio frequency (RF) signals transmitted by the controller 150. The RF signals transmitted by the controller 150 refer to the output signals from the beacon. The control host 170 can analyze the RF signals transmitted by the controller 150 to determine whether the RF signals include the target RF signal. If the RF signals include the target RF signal, the control host 170 issues a prompt signal. The prompt signal can be a light signal. For example, the control host 170 is equipped with an indicator light; when the RF signals include the target RF signal, the indicator light on the control host 170 remains on; when the RF signals do not include the target RF signal, the indicator light turns off. The target RF signal refers to a specific frequency band RF signal emitted by the RF antenna of the measured onboard interrogator, used to activate the ground transponder. The interrogation antenna or RF antenna is installed on the train. For example, the train is equipped with an onboard query device, which includes a query antenna or a radio frequency antenna. The query antenna or radio frequency antenna can be set at the bottom of the train (such as below the locomotive head). When the train is running, it transmits radio frequency signals (i.e., target radio frequency signals) of a specific frequency (such as 4.5MHz, 27MHz, 900MHz) through the query antenna or radio frequency antenna.

[0059] In some embodiments, the control host 170 can determine the absolute position information of the train based on the target radio frequency signal.

[0060] In some embodiments, the control host 170 can also acquire the position information of the beacon component 110 on the slide rail 120, and determine the actual identification window based on the position information and the target radio frequency signal. The identification window refers to the spatial range within which the radio frequency antenna can identify the ground transponder. In some embodiments, the identification window can be the spatial range covered by the radio frequency signal emitted by the radio frequency antenna. In some embodiments, the identification window can be the distance range (also called the length range) of the coverage area of ​​the radio frequency antenna signal in the track laying direction. The actual identification window is the distance range measured by testing means (such as by measuring instruments), while the designed identification window is the theoretically designed distance range. Position information refers to information related to the position of the beacon component 110 on the slide rail 120. Position information includes first position information and second position information. The actual identification window of the radio frequency antenna can also be referred to as the radiation distance of the radio frequency antenna.

[0061] In some embodiments, a grating ruler is provided on or beside the slide rail 120, and a reader is provided on the beacon assembly 110. The reader is signal-connected to the controller 150, and the controller 150 transmits the output signal of the reader to the control host 170, thereby enabling the control host 170 to determine the position information of the beacon assembly when the target radio frequency signal is detected and when the target radio frequency signal disappears.

[0062] In some embodiments, a rotary encoder is mounted on one end of the shaft or screw of the power source. The rotary encoder can detect the rotation angle of the shaft or screw of the power source. The control host 170 can determine the position information of the beacon assembly 110 by the pitch and rotation angle of the shaft or screw. Further explanation regarding determining the radiation distance of the radio frequency antenna based on position information and the target radio frequency signal can be found in [reference needed]. Figure 5 , Figure 6 .

[0063] In some embodiments of this specification, by setting multiple control components (such as buttons and knobs), users can intuitively control the movement direction, speed, or mode of the beacon component, reducing the operational threshold and improving the controllability of the measurement process.

[0064] In some embodiments of this specification, by configuring the beacon component to move automatically along the slide rail and having the controller coordinate the power source and beacon signal, the reliance on manual operation during measurement is significantly reduced, improving the repeatability of the measurement process. The slide rail length is limited to no more than half the maximum radiation distance. Combined with a bidirectional scanning strategy, coverage of the entire radiation range can be completed within a shorter physical travel distance, helping to reduce the overall size of the device and facilitating rapid deployment on-site. The support arms span between the rails, allowing the entire device to be directly erected on the actual operating rail without the need for an additional platform, improving consistency with real-world operating conditions.

[0065] Figure 2A This is a schematic diagram of the first arm according to some embodiments of this specification. Figure 2B This is a schematic diagram of the second arm according to some embodiments of this specification.

[0066] In some embodiments, the lengths of the first arm 130 and the second arm 140 are adjustable. For example, the first arm 130 and the second arm 140 are telescopic rods, and their lengths can be adjusted by telescoping.

[0067] In some embodiments of this specification, by making the lengths of the first arm 130 and the second arm 140 adjustable, the radio frequency antenna radiation distance measuring instrument can be compatible with tracks of different gauges.

[0068] In some embodiments, when the slide rail 120 spans between the first arm 130 and the second arm 140, the distance between the slide rail 120 and the first track 161 and the second track 162 is adjustable. For example, the first arm 130 and the second arm 140 are composed of telescopic rod segments. By adjusting the lengths of the first arm 130 and the second arm 140, the lateral position of the slide rail 120 between the two tracks (such as the first track 161 and the second track 162) can be adjusted. For example, by decreasing the length of the first arm 130 and the second arm 140 at the end near the first track 161 and increasing the length of the first arm 130 and the second arm 140 at the end near the second track 162, the slide rail 120 can be moved closer to the first track 161.

[0069] In some embodiments, the connection point between the slide rail 120 and the first support arm 130 and the second support arm 140 can be laterally displaced. For example, the two ends of the slide rail 120 are provided with lateral grooves or guide rails, allowing the slide rail 120 to move left and right under the support of the support arms. After the slide rail 120 moves to a preset position, it is fixed by a locking member.

[0070] In some embodiments of this specification, the distance between the slide rail 120 and the first track 161 and the second track 162 is adjustable and can be flexibly adjusted to facilitate aligning the beacon with the actual installation offset position of the ground transponder, thereby improving the consistency between the measurement results and the actual identification window.

[0071] In some embodiments, such as Figure 1 , Figure 2A and Figure 2B As shown, the first arm 130 includes a first arm segment 131 and a second arm segment 132, and the second arm 140 includes a third arm segment 141 and a fourth arm segment 142. The first arm segment 131, the second arm segment 132, the third arm segment 141, and the fourth arm segment 142 are all telescopic rods.

[0072] In some embodiments, support arm mounting tubes 121 are respectively provided at both ends of the slide rail 120. One end of the first support arm segment 131 and one end of the second support arm segment 132 are respectively configured to be inserted into the two ends of the support arm mounting tube at one end of the slide rail 120, thereby connecting to form the first support arm 130. One end of the third support arm segment 141 and one end of the fourth support arm segment 142 are respectively configured to be inserted into the two ends of the support arm mounting tube 121 at the other end of the slide rail 120, thereby connecting to form the second support arm 140.

[0073] A telescopic pole may include multiple sub-poles, which are connected by adjusting tubes to form a telescopic tube. Adjusting the length of one or more sub-poles inserted into the adjusting tube changes the overall length of the telescopic pole. For example, refer to... Figure 2A and Figure 2BThe first arm segment 131 includes two sub-rods 131-1 and 131-2 and an adjusting tube 133. The third arm segment 141 includes two sub-rods 141-1 and 141-2 and an adjusting tube 143. The length of the first arm segment 131 can be adjusted by adjusting the lengths of the two sub-rods 131-1 and 131-2 inserted into the adjusting tube 133, and the length of the third arm segment 141 can be adjusted by adjusting the lengths of the two sub-rods 141-1 and 141-2 inserted into the adjusting tube 143. The second arm segment 132 and the fourth arm segment 142 have the same structure as the first arm segment 131 and the third arm segment 141, and will not be described in detail here.

[0074] The lengths of the first arm segment 131, the second arm segment 132, the third arm segment 141, and the fourth arm segment 142 can all be adjusted independently. In some embodiments, the independent adjustment of the lengths of the first arm segment 131, the second arm segment 132, the third arm segment 141, and the fourth arm segment 142 not only allows the radio frequency antenna radiation distance measuring instrument 100 to adapt to tracks with different gauges, but also allows adjustment of the position of the beacon on the vertical line connecting the two tracks by adjusting the length of each arm segment. For example, the lengths of the first arm segment 131 and the third arm segment 141 can be increased, while the lengths of the second arm segment 132 and the fourth arm segment 142 can be decreased, bringing the beacon assembly 110 closer to the first track 161. Alternatively, the lengths of each arm segment can be adjusted to be equal, placing the beacon assembly 110 in the middle of the two tracks.

[0075] In some embodiments, such as Figure 2A and Figure 2B As shown, the first support arm segment 131, the second support arm segment 132, the third support arm segment 141, and the fourth support arm segment 142 have notches at their ends near the track. These segments can be engaged with the track through the notches. The other ends of these segments can be inserted into the support arm mounting tube 121 of the slide rail 120, thus forming the first support arm 130 and the second support arm 140. Simultaneously, the slide rail 120 can also span between the first support arm 130 and the second support arm 140 via the support arm mounting tube 121.

[0076] In some embodiments of this specification, the first and second arms are formed by connecting telescopic arm sections through arm mounting tubes at the ends of the slide rails, making the total length of the arms adjustable to accommodate different track gauges, simplifying on-site assembly and disassembly operations, and enabling quick installation without tools. Each arm section can be independently adjusted in length, supporting asymmetrical extension and retraction, thereby flexibly adjusting the lateral position of the slide rail between the two tracks, and more realistically simulating the non-centered installation state of the actual ground transponder due to construction deviations.

[0077] Figure 3 This is a partial schematic diagram of a beacon component according to some embodiments of this specification. For example... Figure 3 As shown, the beacon assembly 110 also includes a mounting plate 115 and a slider 113.

[0078] In some embodiments, a beacon is disposed on the upper surface of the mounting plate 115. In some embodiments, the mounting plate 115 is rotatably connected to the slider 113, and the mounting plate 115 is capable of rotating relative to the slider 113 in a plane parallel to the upper surface.

[0079] In some embodiments, slider 113 is configured to slide in connection with slide rail 120.

[0080] Mounting plate 115 is the mounting carrier for the beacon. In some embodiments, mounting plate 115 is a rigid plate structure. In some embodiments, mounting plate 115 is rotatably connected to slider 113, and mounting plate 115 can adjust the deflection angle of the beacon by rotating relative to slider 113.

[0081] The upper surface of the mounting plate 115 refers to the side of the mounting plate 115 facing the radio frequency antenna under test. The upper surface of the mounting plate 115 has a planar structure to ensure the stability of the beacon installation.

[0082] A rotatable connection means that when the mounting plate 115 is connected to the slider 113, the mounting plate 115 can rotate relative to the slider 113. For example, the mounting plate 115 can rotate relative to the slider 113 in a plane parallel to the upper surface.

[0083] The slider 113 is a component in the beacon assembly that achieves sliding engagement with the slide rail. In some embodiments, the slider 113 is a block structure adapted to the slide rail 120 structure. The upper surface of the slider 113 is rotatably connected to the mounting plate 115, and the lower surface / side is slidably connected to the slide rail 120. The slider 113 is an intermediate structure connecting the mounting plate 115 (and the beacon) and the slide rail 120, and is also a force-bearing component that drives the beacon assembly 110 to move along the slide rail 120.

[0084] In some embodiments of this specification, the mounting plate 115 and the slider 113 are connected in a manner that allows relative rotation within a horizontal plane. This enables the beacon's orientation angle to be adjusted according to testing requirements, matching the deflection attitude of the actual ground transponder under curved tracks or installation errors. This rotation does not change the beacon's vertical height, helping to maintain consistency in spatial position during measurement. It also provides mechanical feasibility for actively adjusting the beacon's direction to detect radiation boundaries beyond the physical travel of the slide rail, expanding the instrument's applicability within the limited slide rail length.

[0085] In some embodiments, the mounting plate 115 is rectangular. In some embodiments, the beacon is located on one short side of the mounting plate 115, and the connection between the mounting plate 115 and the slider 113 is located on the other short side of the mounting plate 115.

[0086] The shorter side of mounting plate 115 refers to the shorter side of the rectangular mounting plate 115.

[0087] The connection between the mounting plate 115 and the slider 113 refers to the connection part where the mounting plate 115 and the slider 113 can be rotatably connected.

[0088] In some embodiments of this specification, the beacon is arranged on one short side of the mounting plate, and the connection between the mounting plate and the slider is located on the other short side of the mounting plate, so that when the slider moves to the end of the slide rail, the beacon can extend beyond the physical boundary of the slide rail, effectively expanding the detectable area and helping to measure the radiation boundary beyond the length of the slide rail.

[0089] In some embodiments, the beacon assembly 110 further includes a control interface 111, a support arm mounting hole 112, and an adjustment mechanism 114.

[0090] The control interface 111 is the connection port between the beacon component 110 and the controller 150. The control interface 111 is a physical connection component that enables bidirectional electrical and control signal transmission between the beacon component 110 and an external controller (such as controller 150). In some embodiments, the control interface 111 may be located at one end of the slide rail 120. For example, the control interface 111 may be located on the support arm mounting tube at one end of the slide rail 120.

[0091] The support arm mounting hole 112 is an insertion hole for mounting a support arm (such as a first support arm and / or a second support arm). In some embodiments, the support arm mounting hole 112 may be provided at both ends of the slide rail. For example, the support arm mounting hole 112 may be provided on the support arm mounting tube of the slide rail 120. In some embodiments, the inner wall of the support arm mounting hole 112 has anti-slip textures or snap-fit ​​grooves to adapt to the insertion end structure of the support arm segment, thereby preventing the support arm segment from falling off and positioning it after insertion, and ensuring the structural rigidity of the connection.

[0092] The adjustment mechanism 114 is a structure used to adjust the deflection angle of the mounting plate relative to the slider. In some embodiments, the adjustment mechanism 114 may be provided at the connection between the mounting plate 115 and the slider 113.

[0093] In some embodiments, the beacon bracket is sleeved on the slide rail 120 or cooperates with the slide rail 120 track. The beacon bracket is connected to the power source for transmission. The power source is connected to the controller 150 for signal transmission. Under the control of the controller 150, the power source drives the beacon assembly 110 to move along the slide rail 120.

[0094] In some embodiments, the mounting plate 115 and the slider 113 may be part of a beacon holder. In some embodiments, the mounting plate 115 is disposed on the slider 113, and the beacon is fixedly mounted on the mounting plate 115. The mounting plate 115 can rotate relative to the slider 113 in a plane parallel to the upper surface, thereby adjusting the deflection angle of the beacon in that plane. In some embodiments, such as Figure 3 As shown, the beacon's deflection angle can be adjusted via the adjustment mechanism 114. For example, a bushing is fixedly mounted on the upper surface of the slider 113, and a rotating shaft is fixedly mounted on the lower surface of the mounting plate 115. The rotating shaft is inserted into the bushing and can rotate. After adjusting the deflection angle of the mounting plate 115 relative to the slider 113 (i.e., the beacon's deflection angle), the bushing and the rotating shaft are further fixed by a limiting member. The rotating shaft, bushing, and limiting member together constitute the adjustment mechanism 114.

[0095] The limiting component may include a locking sleeve. The limiting component is sleeved on the periphery of the bushing and the rotating shaft. After adjusting the deflection angle of the mounting plate 115 relative to the slider 113, the locking sleeve is tightened to apply a force in the radial direction of the bushing and the rotating shaft, thereby increasing the circumferential friction between the rotating shaft and the bushing and preventing the rotating shaft from rotating relative to the bushing.

[0096] The limiting component may also include a pin, a bushing, and multiple insertion holes distributed around the circumference of the rotating shaft. Each insertion hole on the bushing's circumference has an opposite insertion hole symmetrically positioned relative to the center point of the bushing's cross-section, and each insertion hole on the rotating shaft's circumference also has an opposite insertion hole symmetrically positioned relative to the center point of the rotating shaft's cross-section. By adjusting the deflection angle of the mounting plate 115 relative to the slider 113, and aligning one insertion hole and its opposite insertion hole on the rotating shaft with one insertion hole and its opposite insertion hole on the bushing, the pin is passed through the aforementioned four insertion holes, thereby preventing the rotating shaft from rotating relative to the bushing.

[0097] Figure 4 This is an exemplary flowchart illustrating a measurement method for a radio frequency antenna radiation distance measuring instrument according to some embodiments of this specification. Figure 4 As shown, process 400 includes the following steps.

[0098] Step 410: Install the measuring instrument on the first and second tracks below the radio frequency antenna of the vehicle-mounted query device being measured.

[0099] The measuring instrument refers to an instrument for measuring the radiation distance of a radio frequency antenna. For more information on instruments for measuring the radiation distance of radio frequency antennas, please refer to [link to relevant documentation]. Figures 1-3 .

[0100] The measured on-board interrogator refers to a rail transit signal interaction device installed on a train and equipped with a radio frequency antenna. The measured on-board interrogator is the object of measurement for the radiation distance of the radio frequency antenna.

[0101] A radio frequency (RF) antenna is a signal transmitting component integrated into the vehicle-mounted interrogator being measured. RF antennas transmit radio frequency signals in a specific frequency band to activate ground transponders. The effective detection range of the target RF signal transmitted by the RF antenna is the radiation distance. The RF antenna of the vehicle-mounted interrogator can also be called an interrogation antenna.

[0102] The first and second tracks are parallel rail transit tracks. They also serve as the mounting platform for measuring instruments. The first and second tracks are two parallel tracks on the same rail line.

[0103] In some embodiments, refer to Figure 2A and Figure 2B The notches on the first arm segment 131 and the second arm segment 132 can be engaged with the second track 162 and the first track 161 respectively, and the notches on the third arm segment 141 and the fourth arm segment 142 can be engaged with the second track 162 and the first track 161 respectively, so as to install the measuring instrument on the first track and the second track.

[0104] Step 420: Adjust the position of the beacon on the vertical line connecting the first and second tracks and the deflection angle of the beacon relative to the slide rail based on the installation method of the ground transponder corresponding to the vehicle-mounted interrogator on the track.

[0105] A ground transponder is a ground-based rail transit signaling device used in conjunction with the onboard interrogator being measured. The ground transponder is installed between the first and second tracks. The ground transponder can receive the target radio frequency signal from the radio frequency antenna. For more information on the target radio frequency signal, please refer to [link to relevant documentation]. Figure 1 .

[0106] In some embodiments, the vehicle-mounted interrogator and its corresponding ground transponder are installed on the train and on the track, respectively, and are in use. In this case, the mounting method of the ranging instrument should refer to the already installed ground transponder, and the two should be kept as consistent as possible. For example, if the ground transponder is shifted 50mm to the left due to construction reasons, the beacon should be synchronously shifted to the same position. For example, the lengths of each support arm segment (such as the first support arm segment 131, the second support arm segment 132, the third support arm segment 141, and the fourth support arm segment 142) are adjusted so that the position of the beacon assembly, especially the beacon on the vertical line connecting the first and second tracks, is consistent with the position of the ground transponder on the same line. Furthermore, the deflection angle of the mounting plate can be adjusted so that the deflection angle of the beacon (such as the angle between the beacon axis and the vertical line connecting the first and second tracks) is consistent with the deflection angle of the ground transponder (such as the angle between the ground transponder axis and the vertical line connecting the first and second tracks).

[0107] In some embodiments, the position of the ranging instrument on the track can be adjusted so that when the beacon is in the middle position of the slide rail, the beacon can be as close as possible to the query antenna of the vehicle-mounted query device. For example, the beacon can be brought as close as possible to the query antenna of the vehicle-mounted query device by adjusting the engagement positions of the first arm segment 131, the second arm segment 132, the third arm segment 141, and the fourth arm segment 142 with the first or second track.

[0108] In some embodiments, by adjusting the position of the beacon on the vertical line connecting the first and second tracks, the lateral position of the beacon can be made completely consistent with the ground transponder, ensuring that the boundary of the radio frequency signal detected by the beacon is the effective radiation boundary of the ground transponder when the vehicle-mounted interrogator is actually working. In some embodiments, by adjusting the deflection angle of the beacon relative to the slide rail, the signal receiving direction of the beacon can be made consistent with the ground transponder, avoiding changes in signal detection sensitivity due to angle deviation.

[0109] Step 430: Determine the nominal radiation distance of the radio frequency antenna.

[0110] The nominal radiation distance refers to the designed expected or standard value of the effective radiation distance of a radio frequency antenna. The nominal radiation distance is a calibration parameter of the vehicle-mounted query device.

[0111] In some embodiments, the nominal radiation distance is 0.75m or 1.5m.

[0112] In some embodiments, the nominal radiation distance can be determined using information such as the model and instruction manual of the on-board unit being measured.

[0113] Step 440: Select the measurement procedure corresponding to the nominal value of the radiation distance to measure the radiation distance of the radio frequency antenna.

[0114] In some embodiments, the nominal radiation distance is a theoretical ideal value. In actual application scenarios, there may be slight positional and angular deviations in the installation of the RF antenna on the train, and deviations may also occur in the on-site installation of the ground transponder due to construction precision issues. Furthermore, external factors such as the electromagnetic environment along the track and changes in temperature and humidity can also affect the actual radiation propagation of the RF signal. Therefore, the nominal radiation distance may not reflect the true radiation state of the RF antenna in actual engineering scenarios, and it is necessary to measure the actual radiation distance of the RF antenna.

[0115] In some embodiments, different nominal radiation distance values ​​correspond to different measurement procedures. In some embodiments, when the nominal radiation distance value does not exceed the length of the slide rail, a method such as... Figure 5 The procedure 500 shown measures the radiation distance of the radio frequency antenna. In some embodiments, when the nominal radiation distance is greater than the slide rail length but less than or equal to twice the slide rail length, a method such as... Figure 6 The procedure shown in step 600 measures the radiation distance of the radio frequency antenna.

[0116] In some embodiments of this specification, by adjusting the position and orientation of the beacon with reference to the actual installation method of the ground transponder, the test conditions are made closer to the real working state. Combined with the nominal value, the appropriate measurement procedure is selected, which helps to obtain the boundary point by adopting the optimal strategy under different radiation ranges, thereby improving measurement efficiency and reliability.

[0117] Figure 5 This is an exemplary flowchart illustrating the determination of the radiation distance of a measured radio frequency antenna according to some embodiments of this specification. In some embodiments, process 500 may be executed by a processing device (such as controller 150 and / or control host 170). In some embodiments, process 500 includes the following steps.

[0118] Step 510: Obtain the electromagnetic wave signal received by the beacon according to the preset frequency, and analyze the electromagnetic wave signal to determine whether it includes the target radio frequency signal emitted by the measured antenna.

[0119] The preset frequency refers to the fixed sampling frequency at which the host controls the periodic acquisition of the beacon output signal.

[0120] In some embodiments, the preset frequency is not less than twice the target radio frequency signal frequency.

[0121] In some embodiments of this specification, the preset frequency is not less than twice the frequency of the target radio frequency signal, which can avoid signal aliasing, ensure a reliable judgment on the presence or absence of the target radio frequency signal, and reduce the risk of false detection or missed detection.

[0122] The electromagnetic wave signals received by the beacon include the target radio frequency signal emitted by the radio frequency antenna under test, as well as other clutter signals in the environment where the beacon is located. For ease of explanation, the electromagnetic wave signals described in the embodiments of this specification refer to the electromagnetic wave signals received by the beacon.

[0123] The antenna being measured refers to the radio frequency antenna mounted on the vehicle-mounted query device being measured.

[0124] In some embodiments, the control host can perform real-time analysis of the electromagnetic wave signal received by the beacon using methods such as spectrum analysis (e.g., Fourier transform) and feature recognition to determine whether the electromagnetic wave signal received by the beacon includes the frequency range of the target radio frequency signal, and thus determine whether the electromagnetic wave signal received by the beacon includes the target radio frequency signal emitted by the measured antenna. Further information regarding the target radio frequency signal can be found in [link to relevant documentation]. Figure 1 .

[0125] Step 520: After the beacon component moves to the middle position of the slide rail, it continues to move to one end of the slide rail.

[0126] In some embodiments, the control host can send motion commands to the controller, which drives a power source (such as a stepper motor) to move the beacon component linearly along the slide rail until it reaches the geometric midpoint of the slide rail. In some embodiments, after the beacon component reaches the midpoint, the control host continues to send motion commands in the same direction (i.e., motion commands that do not change the direction of motion) to the controller, driving the beacon component to move continuously towards one end of the slide rail. For example, see... Figure 1 The control host can send motion commands to the controller, which drives the power source (such as a stepper motor) to move the beacon component in a straight line along the slide rail in the X direction until it reaches the geometric midpoint of the slide rail. After the beacon component reaches the midpoint, the control host continues to send motion commands in the same direction to the controller, driving the beacon component to move continuously along the X direction towards one end of the slide rail.

[0127] In some embodiments of this specification, during the installation of the ranging instrument, after the beacon has been positioned in the middle of the slide rail through position adjustments, the beacon and the query antenna of the vehicle-mounted query device are brought as close as possible. Moving the beacon assembly to the middle of the slide rail ensures that the electromagnetic wave signal received by the beacon necessarily includes the target radio frequency signal. By first moving the beacon assembly to the middle of the slide rail and then controlling its movement towards one end of the slide rail, the critical position where the electromagnetic wave signal transitions from including the target radio frequency signal to not including it can be quickly located, thereby improving the measurement efficiency of the radiation distance of the radio frequency antenna.

[0128] Step 530: When the beacon component continues to move towards one end of the slide rail, and the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, the first position information of the beacon component is determined, and the beacon component is controlled to move in the opposite direction on the slide rail.

[0129] The first position information refers to the information characterizing the first position. The first position refers to the instant when the electromagnetic wave signal changes from including the target radio frequency signal to excluding it as the beacon component moves along the slide rail to one end. The first position is one of the boundary points of the radio frequency antenna's radiation range.

[0130] In some embodiments, as the beacon component continuously moves toward one end of the slide rail, the control host correlates the electromagnetic wave signal analysis results with the beacon component's position information in real time. When the electromagnetic wave signal received by the beacon changes from including the target radio frequency signal to excluding the target radio frequency signal, the position information of the beacon component at this moment is immediately recorded as the first position information.

[0131] In some embodiments, a grating ruler is provided on or beside the slide rail, and a reader is provided on the beacon component. The reader is signal-connected to the controller, and the controller transmits the output signal of the reader to the control host. During the measurement process, the reader continuously acquires the displacement pulse signal of the grating ruler and transmits the output signal to the controller in real time. The controller then synchronously forwards the received pulse signal to the control host, realizing the transmission of displacement detection signal from the acquisition end to the control end. When the control host detects the instant when the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, it immediately performs the recording operation of the first position information. Specifically, this critical position can be used as the first position, the first position information can be calibrated to the value 0, and from this moment, pulse counting is performed based on the output signal subsequently transmitted by the reader, providing a continuous pulse data reference for the subsequent acquisition of the second position information and the calculation of the displacement difference.

[0132] In some embodiments, a rotary encoder is installed at the power source shaft that drives the beacon assembly, or at one end of the ball screw connected to the power source. The rotary encoder is used to accurately detect the rotation angle of the power source (such as a stepper motor). Since the rotational motion of the stepper motor is converted into the linear movement of the beacon assembly along the slide rail through the ball screw, there is a fixed transmission correspondence between the two. Therefore, the actual linear displacement of the beacon assembly along the slide rail can be calculated by using the screw pitch and the rotation angle detected by the rotary encoder. When the control host detects the critical moment when the electromagnetic wave signal received by the beacon changes from including the target radio frequency signal to not including the target radio frequency signal, it directly extracts the rotation angle parameter output by the current rotary encoder. Based on this angle parameter, the first position information is determined and recorded. This rotation angle parameter provides the original angle reference for the subsequent acquisition of the second position information and the calculation of the final displacement difference.

[0133] In some embodiments, after determining the first position information, the control host synchronously sends a reverse motion command to the controller. The controller drives the power source to immediately stop the beacon component's movement in the current direction and start moving in the opposite direction along the slide rail. For example, if the beacon component is moving in the X direction, after determining the first position information, the control host controls the beacon component to move in the opposite direction (i.e., in the Y direction) on the slide rail.

[0134] In some embodiments, when the beacon assembly continues to move toward one end of the slide rail and reaches that end, the electromagnetic wave signal still includes the target radio frequency signal. Then: the mounting plate is adjusted so that the long side of the mounting plate is parallel to the slide rail, and the beacon faces the outside of one end of the slide rail, so that the electromagnetic wave signal does not include the target radio frequency signal; the beacon assembly is controlled to move in the opposite direction; when the beacon assembly moves in the opposite direction and the electromagnetic wave signal changes from not including the target radio frequency signal to including the target radio frequency signal, the first position information is determined.

[0135] The long side of a mounting plate refers to the longer side of the mounting plate. The long side of the mounting plate is perpendicular to the short side.

[0136] The outer side of one end of the slide rail refers to the spatial region extending outward from one end of the slide rail beyond its physical length boundary. This region lies outside the extension direction of the slide rail and is the area that the beacon can detect after rotating the mounting plate. In other words, by adjusting the mounting plate so that its long side is parallel to the slide rail and the beacon faces outward from one end of the slide rail, the beacon can extend beyond the slide rail's range, increasing the range of electromagnetic waves it can receive.

[0137] The distance of the long side of the mounting plate ranges from 200mm to 400mm. The distance of the long side can be adjusted according to the actual needs of the embodiment.

[0138] Because the radiation range of the radio frequency antenna is limited (less than the length of the slide rail), when the long side of the rotating mounting plate is parallel to the slide rail, the beacon is rotated to the outside of the slide rail, exceeding the radiation range of the radio frequency antenna, and therefore the beacon cannot receive the target radio frequency signal. In some embodiments, when the beacon is facing the outside of one end of the slide rail and the electromagnetic wave signal does not include the target radio frequency signal, the control host controls the beacon assembly to move in the opposite direction (e.g., when the beacon is facing the outside of the X-direction end of the slide rail, the control host controls the beacon assembly to move in the opposite Y-direction). During the reverse movement, the control host continuously monitors the electromagnetic wave signal received by the beacon, and when it detects the instant that the electromagnetic wave signal state changes from not including the target radio frequency signal to including the target radio frequency signal, it immediately records the position of the beacon assembly at this time as the first position information.

[0139] Step 540: When the beacon component moves in the reverse direction and the electromagnetic wave signal changes again from including the target radio frequency signal to not including the target radio frequency signal, the second position information of the beacon component is determined.

[0140] The second position information refers to information characterizing the second position. As the beacon component moves in the opposite direction (the direction opposite to the direction determining the first position information) along the slide rail, it will again exceed the radiation distance of the radio frequency antenna. This causes the electromagnetic wave received by the beacon to change again from including the target radio frequency signal to excluding it. The position of the beacon component at this moment is the second position. The position information of the beacon component at this time is immediately recorded as the second position information. The second position is another boundary point of the radio frequency antenna's radiation distance.

[0141] In some embodiments, a grating ruler is provided on or beside the slide rail, and a reader is provided on the beacon component. The reader is signal-connected to the controller, and the controller transmits the output signal of the reader to the control host. The control host records the number of pulses corresponding to the moment when the electromagnetic wave changes from including the target radio frequency signal to not including the target radio frequency signal, and determines the second position information based on the number of pulses.

[0142] In some embodiments, a rotary encoder is installed at the power source shaft that drives the beacon assembly, or at one end of the ball screw connected to the power source drive. The rotary encoder is used to accurately detect the rotation angle of the power source (such as a stepper motor). The control host determines the second position information based on the moment when the electromagnetic wave changes again from including the target radio frequency signal to not including the target radio frequency signal, and the rotation angle output by the rotary encoder.

[0143] In some embodiments, when the beacon assembly moves in the reverse direction and reaches the other end of the slide rail, the electromagnetic wave signal still includes the target radio frequency signal. Then: the mounting plate is adjusted so that the long side of the mounting plate is parallel to the slide rail and the beacon faces the outside of the other end of the slide rail so that the electromagnetic wave signal does not include the target radio frequency signal; the beacon assembly is controlled to move in the reverse direction again; when the beacon assembly moves in the reverse direction again and the electromagnetic wave signal changes from not including the target radio frequency signal to including the target radio frequency signal, the second position information is determined.

[0144] For example, when the beacon assembly moves in the Y direction (the opposite of the X direction) and reaches the other end of the slide rail, the electromagnetic wave signal still includes the target radio frequency signal. Therefore: adjust the mounting plate so that its long side is parallel to the slide rail and the beacon faces the outer side of the section of the slide rail facing the Y direction, so that the electromagnetic wave signal does not include the target radio frequency signal. Control the beacon assembly to move in the opposite direction again, i.e., in the X direction. During this second reverse movement, the control host continuously monitors the electromagnetic wave signal received by the beacon. When it detects the instant the electromagnetic wave signal state changes from not including the target radio frequency signal to including it, it immediately records the position of the beacon assembly at this moment as secondary position information.

[0145] In some embodiments of this specification, by adjusting the mounting plate so that its long side is parallel to the slide rail and the beacon faces outward from one end of the slide rail, the effective boundary can still be located even with the limited length of the slide rail, thus expanding the instrument's applicability to a larger radiation distance.

[0146] Step 550: Determine the radiation distance of the measured radio frequency antenna based on the first location information and the second location information.

[0147] In some embodiments, the control host can determine the displacement of the beacon component based on the first position information and the second position information, and determine the radiation distance of the measured radio frequency antenna based on the displacement of the beacon component.

[0148] In some embodiments, the control host can determine the displacement value of the beacon component based on the number of pulses when recording the first position information and the second position information and the unit displacement corresponding to a single pulse, and determine the displacement value of the beacon component as the radiation distance of the radio frequency antenna.

[0149] In some embodiments, the control host can determine the difference between the rotation angle of the rotary encoder when recording the second position information and the rotation angle of the rotary encoder when recording the first position information, determine the displacement value of the beacon assembly based on the difference in rotation angle and the screw pitch, and determine the displacement value of the beacon assembly as the radiation distance of the radio frequency antenna. The displacement value of the beacon assembly is determined based on the following formula (1): (1) Where S represents the displacement value of the beacon component. 'b' represents the difference in rotation angle, and 'b' represents the screw pitch.

[0150] In some embodiments, when the mounting plate is adjusted so that its long side is parallel to the slide rail, the control host can determine the displacement value of the beacon component based on the first position information and the second position information; and determine the radiation distance based on the displacement value and the offset.

[0151] The offset reflects the distance between the beacon's mapped position on the long side of the mounting plate and the connector's mapped position on the long side of the mounting plate.

[0152] The mapping position of the beacon on the long side of the mounting plate refers to the virtual point obtained by projecting the actual physical mounting point of the beacon onto the long side of the mounting plate in a direction perpendicular to the long side of the mounting plate. The mapping position of the connecting part on the long side of the mounting plate refers to the virtual point obtained by projecting the rotatable connecting part between the mounting plate and the slider onto the long side of the mounting plate in a direction perpendicular to the long side of the mounting plate.

[0153] In some embodiments, when the mounting plate is adjusted only at one end of the slide rail so that the long side of the mounting plate is parallel to the slide rail, the radiation distance of the radio frequency antenna can be determined based on the displacement value and the offset. For example, the radiation distance of the radio frequency antenna is the sum of the displacement value and the offset.

[0154] In some embodiments, when the mounting plates are adjusted simultaneously at both ends of the slide rail so that the long side of the mounting plate is parallel to the slide rail, the radiation distance of the radio frequency antenna can be determined based on the displacement value and the offset. For example, the radiation distance of the radio frequency antenna is the sum of the displacement value and twice the offset.

[0155] In some embodiments of this specification, by introducing an offset to compensate for the geometric deviation between the actual detection point of the beacon and the position of the slider, the radiation distance calculated based on the slider displacement is made closer to the actual physical distance, thereby improving the accuracy of the results.

[0156] In some embodiments of this specification, when the nominal radiation distance does not exceed the length of the slide rail, by moving from the midpoint to one end and recording the first position when the signal goes from present to absent, and then immediately moving in the opposite direction and recording the second position when the signal goes from present to absent again, it is possible to completely capture the two boundaries of the radiation range in a single continuous round trip. By utilizing the approximately symmetrical characteristics of the vehicle-mounted radio frequency field in the track direction, repeated positioning or invalid return trips are avoided, which helps to efficiently and accurately determine the radiation distance of the radio frequency antenna, while reducing the operational complexity and time overhead in the measurement process.

[0157] Figure 6 This is an exemplary flowchart illustrating the determination of the radiation distance of a measured radio frequency antenna according to other embodiments of this specification. In some embodiments, process 600 may be executed by a processing device (such as controller 150 and / or control host 170). In some embodiments, process 600 includes the following steps.

[0158] Step 610: Obtain the electromagnetic wave signal received by the beacon according to the preset frequency, and analyze the electromagnetic wave signal to determine whether it includes the target radio frequency signal emitted by the measured antenna, and calculate the strength of the target radio frequency signal if it includes the target radio frequency signal.

[0159] In some embodiments, the control host can calculate the strength of the target radio frequency signal based on the analysis results of the electromagnetic wave signal. For example, if the control host analyzes the electromagnetic wave signal and finds that it includes the target radio frequency signal, it immediately calculates the field strength value (i.e., signal strength) of the target radio frequency signal based on the Fourier transform result of the electromagnetic wave signal analysis.

[0160] In some embodiments, the control host can also associate and store the signal strength value with the current position information of the beacon component, forming a corresponding data set of "beacon component position - target radio frequency signal strength". The position information of the beacon component can be determined based on the number of grating ruler pulses or the angle of the rotary encoder.

[0161] The method of acquiring the electromagnetic wave signal received by the beacon according to the preset frequency, analyzing the electromagnetic wave signal, and then determining whether it includes the target radio frequency signal emitted by the measured antenna is the same as in step 510. For details, please refer to the relevant description in step 510.

[0162] Step 620: Control the beacon component to move on the slide rail and the movement range covers the entire slide rail.

[0163] In some embodiments, the control host can issue motion commands. After receiving the motion commands, the controller drives the power source (stepper motor) to operate. Through the transmission of the ball screw, the beacon component moves linearly from any starting position towards one end of the slide rail (e.g., the end of the slide rail facing the X direction) until it reaches the physical limit of that end. Subsequently, the control host automatically issues motion commands in the opposite direction, driving the beacon component to continue moving from that end to the other end of the slide rail (e.g., the end of the slide rail facing the Y direction) until it reaches the physical limit of the other end, so that the movement range of the beacon component covers the entire slide rail.

[0164] In some embodiments, as the beacon component moves on the slide rail, the control host can analyze the electromagnetic wave signal in real time to determine whether it includes the target radio frequency signal emitted by the measured antenna, and calculate the strength of the target radio frequency signal if it is included.

[0165] Step 630: Determine a reference position based on the position information of the beacon component when the strength of the target radio frequency signal is at its maximum value; determine first position information based on the reference position; and control the beacon component to move from the reference position to one end of the slide rail.

[0166] The reference position refers to the position of the beacon component when the strength of the target radio frequency signal is at its maximum.

[0167] In some embodiments, the control host can perform extreme value analysis on the corresponding data set of "beacon component position - target radio frequency signal strength" obtained from the full slide rail scan, and filter out the beacon component position information corresponding to the maximum value of the target radio frequency signal strength, and use this position as the reference position. In some embodiments, the reference position is the midpoint of the radio frequency antenna radiation distance.

[0168] In some embodiments, the control host may use a reference position as the first position.

[0169] In some embodiments, the control host can control the beacon component to move to a reference position and then move towards one end of the slide rail from the reference position. The direction of movement from the reference position towards one end of the slide rail can be randomly selected by the control host or manually controlled by the user.

[0170] Step 640: As the beacon component moves from the reference position toward one end of the slide rail, and the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, the second position information of the beacon component is determined.

[0171] In some embodiments, as the beacon component moves from a reference position toward one end of the slide rail, the control host continuously monitors whether the electromagnetic wave signal includes the target radio frequency signal emitted by the measured antenna and the position information of the beacon component. When the control host detects the instant that the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, it immediately records the position information of the beacon component at this time and uses this information as the second position information.

[0172] Step 650: When the beacon component moves from the reference position to one end of the slide rail, if the electromagnetic wave signal does not change from including the target radio frequency signal to not including the target radio frequency signal, then control the beacon component to move in the opposite direction.

[0173] In some embodiments, as the beacon component moves from the reference position toward one end of the slide rail until it reaches the physical limit of that end of the slide rail (i.e., the beacon component can no longer move), the electromagnetic wave signal detected by the control host still includes the target radio frequency signal. The control host sends a motion command to the controller to move in the opposite direction. The controller controls the power source to make the beacon component move in a uniform linear motion in the opposite direction (i.e., the direction of the reference position) starting from the physical limit position of that end of the slide rail.

[0174] Step 660: When the beacon component moves in the reverse direction and the electromagnetic wave signal changes from excluding the target radio frequency signal to including the target radio frequency signal, determine the second position information of the beacon component.

[0175] In some embodiments, if the beacon component is still in a signal state before moving in the opposite direction from one end of the slide rail, the long side of the mounting plate can be adjusted to be parallel to the slide rail, and the beacon can be directed towards the outside of one end of the slide rail so that the electromagnetic wave signal does not include the target radio frequency signal.

[0176] In some embodiments, during the reverse movement of the beacon component, the control host continuously monitors whether the electromagnetic wave signal includes the target radio frequency signal emitted by the measured antenna and the position information of the beacon component. When the electromagnetic wave signal changes from not including the target radio frequency signal to including the target radio frequency signal, the position information of the beacon component at this moment is recorded and used as the second position information.

[0177] Step 670: Determine the radiation distance of the measured radio frequency antenna based on the first location information and the second location information.

[0178] In some embodiments, since the reference position corresponding to the first position is the midpoint of the radio frequency antenna radiation distance, the radio frequency antenna radiation distance is twice the beacon component displacement value determined based on the first position information and the second position information.

[0179] In some embodiments, the control host can determine the displacement value of the beacon component based on the number of pulses recorded when recording the first and second position information and the unit displacement corresponding to a single pulse, and determine the radiation distance of the radio frequency antenna based on the displacement value of the beacon component. For example, the radiation distance of the radio frequency antenna is twice the displacement value of the beacon component.

[0180] In some embodiments, the control host can determine the difference between the rotation angle of the rotary encoder when recording the second position information and the rotation angle of the rotary encoder when recording the first position information, determine the displacement value of the beacon assembly based on the difference in rotation angle and the screw pitch, and determine the radiation distance of the radio frequency antenna based on the displacement value of the beacon assembly. For example, the radiation distance of the radio frequency antenna is twice the displacement value of the beacon assembly. The displacement value of the beacon assembly is determined based on formula (1).

[0181] In some embodiments, before the beacon assembly moves in the opposite direction from one end of the slide rail, if the mounting plate has been adjusted so that its long side is parallel to the slide rail and the beacon faces outward from one end of the slide rail, ensuring that the electromagnetic wave signal does not contain the target radio frequency signal, the control host can determine the displacement value of the beacon assembly based on the first position information and the second position information; and determine the radiation distance based on the displacement value and the offset. For example, the control host can determine the displacement value and the offset of the beacon assembly, and use twice the displacement value and the offset as the radiation distance of the radio frequency antenna. Further explanation of the offset can be found in [link to relevant documentation]. Figure 5 .

[0182] In some embodiments of this specification, when the radiation distance exceeds the length of the slide rail but does not exceed twice that length, the position with the maximum signal strength is determined by scanning the entire slide rail as a reference center, and the boundary is probed unidirectionally from this point. If the boundary exceeds the range of the slide rail, the signal recurrence point is captured by moving in the opposite direction to indirectly locate the point, so that the complete radiation distance can still be reasonably estimated within a limited travel distance, taking into account both measurement feasibility and result reliability.

[0183] In some embodiments, if the electromagnetic wave signal contains the target radio frequency signal regardless of the beacon component's position on the slide rail, the mounting plate is adjusted so that its long side is parallel to the slide rail, and the measurement procedure corresponding to the nominal radiation distance is re-executed. For example, when the nominal radiation distance does not exceed the length of the slide rail, the control host can execute the measurement procedure shown in procedure 500 to determine the radiation distance of the radio frequency antenna. As another example, when the nominal radiation distance is greater than the slide rail length but less than or equal to twice the slide rail length, the control host can execute the measurement procedure shown in procedure 600 to determine the radiation distance of the radio frequency antenna.

[0184] In some embodiments of this specification, adjusting the beacon orientation to be parallel to the slide rail can not only expand the measurement range of the measuring instrument for the radiation distance of the radio frequency antenna, but also change the effective receiving direction of the beacon, reduce the sensitivity to strong field areas, and help expose the true boundary in over-coverage scenarios, avoiding misjudgment of excessive radiation distance.

[0185] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Furthermore, this specification uses specific terms to describe embodiments, such as "an embodiment." "An Example" The terms "and / or some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "an alternative embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment.

[0186] It should be noted that, in order to simplify the descriptions disclosed herein and thus aid in the understanding of one or more embodiments, the foregoing description of embodiments in this specification sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

Claims

1. A radio frequency antenna radiation distance measuring instrument, characterized in that, include: The system includes a beacon assembly, a slide rail, a first arm, a second arm, a power source, and a controller; the beacon assembly includes a beacon capable of detecting the radio frequency signal emitted by the radio frequency antenna under test. The first arm and the second arm are respectively configured to span between the parallel first track and the second track; The slide rail is configured to span between the first arm and the second arm; The beacon component is configured to be slidably connected to the slide rail; The power source is configured to be drive-connected to the beacon assembly, thereby driving the beacon assembly to move along the slide rail; The controller is configured to connect to the power source and the beacon signal respectively, thereby controlling the power source to drive the beacon component to move and to receive the output signal of the beacon; The length of the slide rail shall not exceed half of the maximum value of the radiation distance of the two or more radio frequency antennas under test.

2. The instrument according to claim 1, characterized in that, The length of the slide rail is 0.75m.

3. The instrument according to claim 1, characterized in that, The lengths of the first arm and the second arm are adjustable.

4. The instrument according to claim 1, characterized in that, When the slide rail is positioned between the first support arm and the second support arm, the distance between the slide rail and the first track and the second track is adjustable.

5. The instrument according to claim 4, characterized in that, The first arm includes a first arm segment and a second arm segment, the second arm includes a third arm segment and a fourth arm segment, and the first arm segment, the second arm segment, the third arm segment and the fourth arm segment are all telescopic rods; Support arm mounting tubes are respectively provided at both ends of the slide rail; One end of the first support arm segment and one end of the second support arm segment are respectively configured to be inserted into the two ends of the support arm mounting tube at one end of the slide rail, thereby connecting to form the first support arm; One end of the third support arm segment and one end of the fourth support arm segment are respectively configured to be inserted into the two ends of the support arm mounting tube at the other end of the slide rail, thereby connecting to form a second support arm.

6. The instrument according to claim 1, characterized in that, The beacon assembly also includes a mounting plate and a slider; The beacon is disposed on the upper surface of the mounting plate; The mounting plate is rotatably connected to the slider, and the mounting plate is capable of rotating relative to the slider in a plane parallel to the upper surface. The slider is configured to slide in connection with the slide rail.

7. The instrument according to claim 6, characterized in that, The mounting plate is rectangular, the beacon is located on one short side of the mounting plate, and the connection between the mounting plate and the slider is located on the other short side of the mounting plate.

8. The instrument according to claim 1, characterized in that, The instrument also includes a control host, which is configured to have a signal connection with the controller; The controller is configured to control the power source to drive the beacon assembly to move based on motion commands from the control host and to transmit output signals from the beacon to the control host.

9. The instrument according to claim 8, characterized in that, The control host includes one or more control components, and the control host is used to generate the motion command in response to a user's trigger operation on the one or more control components.

10. A measurement method based on a radio frequency antenna radiation distance measuring instrument as described in any one of claims 1-9, characterized in that, include: The measuring instrument is installed on the first and second tracks below the radio frequency antenna of the vehicle-mounted query device being measured. The position of the beacon on the vertical line connecting the first track and the second track, as well as the deflection angle of the beacon relative to the slide rail, are adjusted based on the installation method of the ground transponder corresponding to the vehicle-mounted interrogator on the track. Determine the nominal radiation distance value of the radio frequency antenna; The radiation distance of the radio frequency antenna is measured by selecting a measurement procedure corresponding to the nominal value of the radiation distance.

11. The method according to claim 10, characterized in that, When the nominal value of the radiation distance does not exceed the length of the slide rail, the measurement process includes: The electromagnetic wave signal received by the beacon is acquired according to a preset frequency, and the electromagnetic wave signal is analyzed to determine whether it includes the target radio frequency signal emitted by the measured antenna. After the beacon component is moved to the middle position of the slide rail, it continues to move to one end of the slide rail; When the beacon component continues to move toward one end of the slide rail, and the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, the first position information of the beacon component is determined, and the beacon component is controlled to move in the opposite direction on the slide rail. When the beacon component moves in the reverse direction, and the electromagnetic wave signal changes again from including the target radio frequency signal to not including the target radio frequency signal, the second position information of the beacon component is determined; Based on the first location information and the second location information, the radiation distance of the measured radio frequency antenna is determined.

12. The method according to claim 11, characterized in that, As the beacon component continues to move toward one end of the slide rail and reaches that end, if the electromagnetic wave signal still includes the target radio frequency signal, then: Adjust the mounting plate so that its long side is parallel to the slide rail, and so that the beacon faces outward from one end of the slide rail, so that the electromagnetic wave signal does not include the target radio frequency signal; Control the beacon component to move in the reverse direction; When the beacon component moves in the reverse direction and the electromagnetic wave signal changes from excluding the target radio frequency signal to including the target radio frequency signal, the first position information is determined.

13. The method according to claim 11 or 12, characterized in that, When the beacon component moves in the reverse direction and reaches the other end of the slide rail, if the electromagnetic wave signal still includes the target radio frequency signal, then: Adjust the mounting plate so that its long side is parallel to the slide rail and the beacon faces outward from the other end of the slide rail so that the electromagnetic wave signal does not include the target radio frequency signal; Control the beacon component to move in the reverse direction again; When the beacon component moves in the opposite direction again, and the electromagnetic wave signal changes from excluding the target radio frequency signal to including the target radio frequency signal, the second position information is determined.

14. The method according to claim 10, characterized in that, When the nominal value of the radiation distance is greater than the length of the slide rail but less than or equal to twice the length of the slide rail, the measurement process includes: The electromagnetic wave signal received by the beacon is acquired according to a preset frequency, and the electromagnetic wave signal is analyzed to determine whether it includes the target radio frequency signal emitted by the measured antenna, and if the target radio frequency signal is included, the strength of the target radio frequency signal is calculated. The beacon assembly is controlled to move on the slide rail, and the movement range covers the entire slide rail. A reference position is determined based on the position information of the beacon component when the strength of the target radio frequency signal is at its maximum value. First position information is determined based on the reference position, and the beacon component is controlled to move from the reference position toward one end of the slide rail. As the beacon component moves from the reference position toward one end of the slide rail, and the electromagnetic wave signal changes from including the target radio frequency signal to not including the target radio frequency signal, the second position information of the beacon component is determined. If the electromagnetic wave signal does not change from including the target radio frequency signal to not including the target radio frequency signal during the process of the beacon component moving from the reference position to one end of the slide rail, then the beacon component is controlled to move in the opposite direction. When the beacon component moves in the reverse direction, and the electromagnetic wave signal changes from excluding the target radio frequency signal to including the target radio frequency signal, the second position information of the beacon component is determined; Based on the first location information and the second location information, the radiation distance of the measured radio frequency antenna is determined.

15. The method according to claim 14, characterized in that, If the electromagnetic wave signal includes the target radio frequency signal when the beacon component is at any position on the slide rail, then the mounting plate is adjusted so that the long side of the mounting plate is parallel to the slide rail, and the measurement procedure corresponding to the nominal value of the radiation distance is re-executed.

16. The method according to claim 12, 13 or 15, characterized in that, Determining the radiation distance of the measured radio frequency antenna based on the first location information and the second location information includes: The displacement value of the beacon component is determined based on the first location information and the second location information; The radiation distance is determined based on the displacement value and the offset, wherein the offset reflects the distance between the mapping position of the beacon on the long side of the mounting plate and the mapping position of the connection on the long side of the mounting plate.

17. The method according to claim 11 or 14, characterized in that, The preset frequency is not less than twice the frequency of the target radio frequency signal.

18. The method according to claim 10, characterized in that, The nominal value of the radiation distance is 0.75m or 1.5m.

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