System and method for adaptive beam steering for highways

Abstract

Systems and methods for monitoring a highway using a radio frequency identification (RFID) detection system. The RFID detection system includes (i) an image sensor configured to have a field of view directed at a lane of the highway; (ii) an RFID transceiver device configured to interrogate RFID tags disposed on vehicles within the lane of the highway; and (iv) a controller operably connected to the image sensor and the RFID transceiver device. The controller is configured to (1) cause the image sensor to capture frames of image data representative of the lane of the highway; (2) analyze the frames of image data to detect the presence of a vehicle within the lane of the highway; (3) based on the analysis, determine a location of the vehicle relative to the RFID transceiver device; and (4) configure an antenna array to produce a beam directed at the location of the vehicle.

Description

Background Technology

[0001] For many types of highways, it is important to track vehicles passing through specific areas. One example is a toll collection system, which tracks vehicles passing through toll zones to ensure that the required toll has been paid. To improve the speed at which vehicles pass through tracked areas, radio frequency identification (RFID) detection systems are used to automatically and wirelessly detect vehicles. In these systems, tracked vehicles are equipped with RFID tags that respond to interrogation signals emitted by the RFID detection system monitoring the tracked area.

[0002] However, conventional RFID detection systems for highway monitoring have several drawbacks. To maximize the reading area, conventional RFID detection systems typically employ omnidirectional antenna systems. As a result, most of the transmission power is not directed towards the RFID tag. This can cause the RFID detection system to miss some vehicles, especially when the RFID tag is in an unconventional location. Furthermore, the omnidirectional nature of conventional antennas reduces the reading range of the RFID detection system in any one direction. Consequently, RFID detection system operators tend to configure RFID detector stations to transmit at the maximum power permitted by applicable regulations. However, the combination of omnidirectional antennas and maximum transmission power often results in transmitted signals reaching vehicles in other lanes monitored by other RFID detector stations. Consequently, vehicles may be double-billed and / or detected by less efficient RFID detector stations.

[0003] As another drawback, conventional RFID detection systems typically configure all their detection stations to be able to interrogate RFID tags approximately simultaneously. However, metal, including in most vehicles, is highly reflective of RF signals, leading to significant multipath interference. Therefore, due to the presence of multipath interference, conventional RFID detection systems may be unable to read interrogation responses from RFID tags. For at least these reasons, there is a need for systems and methods with adaptive beam steering for RFID detection systems used to monitor highways. Summary of the Invention

[0004] In an embodiment, the present invention is a radio frequency identification (RFID) detection system for monitoring highways. The RFID detection system includes (i) an image sensor configured to have a field of view pointing towards the lanes of the highway; (ii) an RFID transceiver device configured to interrogate RFID tags placed on vehicles within the lanes of the highway, wherein the RFID transceiver device includes an antenna array; and (iv) a controller operatively connected to the image sensor and the RFID transceiver device. The controller is configured to (1) cause the image sensor to capture frames of image data representing the lanes of the highway; (2) analyze the frames of image data to detect the presence of vehicles within the lanes of the highway; (3) determine the position of the vehicle relative to the RFID transceiver device based on the analysis; and (4) configure the antenna array to generate a beam pointing towards the position of the vehicle.

[0005] In another embodiment, a method for monitoring a highway using a radio frequency identification (RFID) detection system is provided. The RFID detection system includes (i) an image sensor configured to have a field of view pointing towards a lane of the highway; (ii) an RFID transceiver device configured to interrogate RFID tags placed on vehicles within a lane of the highway, wherein the RFID transceiver device includes an antenna array; and (iii) a controller operatively connected to the image sensor and the RFID transceiver device. The method includes: (1) causing the image sensor to capture frames of image data representing a lane of the highway via the controller; (2) analyzing the frames of image data via the controller to detect the presence of vehicles within a lane of the highway; (3) determining, based on the analysis, the position of a vehicle relative to the RFID transceiver device via the controller; and (4) configuring the antenna array via the controller to generate a beam pointing towards the position of the vehicle. Attached Figure Description

[0006] The accompanying drawings, together with the detailed description below, are incorporated in and form part of this specification, and serve to further illustrate embodiments including the claimed inventive concept, and to explain the various principles and advantages of these embodiments. In the drawings, the same reference numerals denote the same or functionally similar elements in the various views.

[0007] Figure 1 An example highway is shown, including the RFID detection system disclosed herein.

[0008] Figure 2 It shows Figure 1 Example block diagram of the controller.

[0009] Figure 3 It shows Figure 1 Example block diagram of the detector station.

[0010] Figure 4 The selection pointer is shown. Figure 1 The vehicle's beam RFID detection system.

[0011] Figure 5 It is for use Figure 1 A flowchart illustrating an example method of using an RFID detection system to monitor highways.

[0012] Those skilled in the art will understand that the elements in the figures are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be enlarged relative to other elements to aid in a better understanding of embodiments of the invention.

[0013] In the accompanying drawings, the components of the facilities and methods have been indicated by conventional symbols where appropriate, and only those specific details relevant to understanding the embodiments of the invention are shown so as not to obscure the invention by means of details that are obvious to those of ordinary skill in the art who will benefit from the description herein. Detailed Implementation

[0014] Figure 1 Example environment 100 includes a radio frequency identification (RFID) detection system 112 configured to monitor vehicles 115 crossing highway 105. While environment 100 depicts vehicles 115 as cars and trucks and highway 105 as a road, highway 105 can be any path that vehicles 115 traverse. For example, in alternative embodiments, a highway can be a waterway or shipping corridor, a bicycle path, a warehouse corridor or passageway, or any other passageway through which vehicles can pass unimpeded. Accordingly, in alternative embodiments, vehicles 115 can be small boats, ships, bicycles, motorcycles, scooters, forklifts, manned or unmanned warehousing facilities, or any other vehicle capable of crossing the highway. In environment 100, highway 105 includes three lanes 107, but in other embodiments, highway 105 may include more or fewer lanes (in some embodiments, a single lane 107).

[0015] The RFID detection system 112 includes one or more detector stations 30 configured to detect vehicles 115 crossing the highway 105. In the illustrated embodiment, each detector station 30 corresponds to a single lane 107 of the highway 105. That is, detector station 30a is configured to detect vehicles 115 crossing lane 107a, detector station 30b is configured to detect vehicles 115 crossing lane 107b, and detector station 30c is configured to detect vehicles 115 crossing lane 107c. It should be understood that, in alternative embodiments, a single detector station 30 may be positioned between two lanes 107, such that the detector station 30 is configured to detect vehicles crossing either lane 107. In environment 100, the detector stations 30 are positioned on a truss or other structure above the highway 105. In other embodiments, the detector stations 30 may be positioned in other locations (e.g., along the exterior of the highway 105, between the lanes 107 of the highway 105, or within a unit located in and / or below the road surface of the highway 105 itself). As further described herein, detector station 30 includes an RFID transceiver device capable of detecting RFID tags 117 affixed to vehicle 115. For example, the RFID tag may be affixed to the vehicle's windshield (e.g., RFID tags 117a and 117d), to the vehicle's roof and / or to a trailer associated with the vehicle (e.g., RFID tag 117), to a license plate assembly (e.g., RFID tag 117c), or to other locations on the vehicle. Detector station 30 also includes an image sensor configured to capture frames of image data indicating lane 107 monitored by detector station 30.

[0016] The RFID detection system 112 also includes a controller 16, which can be operated by personnel associated with the highway and / or the RFID detection system 112. In environment 100, the controller 16 is housed in the same structure as the detector station 30. In other embodiments, the controller 16 may be located in an operator-accessible enclosure (not shown) near the detector station 30. Therefore, the controller 16 may include a networked host computer, server, or other type of programmable controller. Each detector station 30 may communicate electronically with the controller 16 either wired or wirelessly. For example, in some embodiments, the detector station 30 may be connected via Category 5 or Category 6 cable and use the Ethernet standard for wired communication. In other embodiments, the detector station 30 may be wirelessly connected using a built-in wireless transceiver and may use the IEEE 802.11 (WiFi) and / or Bluetooth standards for wireless communication. Other embodiments may include detector stations 30 using a combination of wired and wireless communication.

[0017] Figure 2It means that it is able to achieve, for example Figure 1 Example RFID detection system 112, or more specifically, implements one or more components. Figure 1 A block diagram of the example logic circuit for example controller 16. Figure 2 The example logic circuit is a processing platform 200 capable of executing instructions to implement, for example, the operations of the example methods described herein, as can be represented by flowcharts in the accompanying drawings. Other example logic circuits capable of implementing, for example, the operations of the example methods described herein include field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs).

[0018] Figure 2 The example processing platform 200 includes a processor 202, such as one or more microprocessors, controllers, and / or any suitable type of processor. Figure 2 The example processing platform 200 includes a memory (e.g., volatile memory, non-volatile memory) 204 that can be accessed by a processor 202 (e.g., via a memory controller). The example processor 202 interacts with the memory 204 to obtain, for example, machine-readable instructions stored in the memory 204 corresponding to operations, such as those represented by the flowcharts of the present invention. Additionally or alternatively, the machine-readable instructions corresponding to the example operations described herein may be stored on one or more removable media (e.g., compressed optical disc, digital universal optical disc, removable flash memory, etc.) that can be coupled to the processing platform 200 to provide access to the machine-readable instructions stored thereon.

[0019] Figure 2 The example processing platform 200 also includes a network interface 206 to enable communication with other machines via, for example, one or more networks. The example network interface 206 includes any suitable type of communication interface (e.g., wired and / or wireless interface) configured to operate according to any suitable protocol. For example, the processing platform 200 may use a first communication interface (e.g., Ethernet) to communicate with detector station 30 and a second communication interface (e.g., WiFi) to communicate with a central server 14 that merges data from multiple RFID detection systems.

[0020] Figure 2 The example processing platform 200 also includes an input / output (I / O) interface 208 to enable receiving user input and communicating output data to the user.

[0021] Figure 3This is a block diagram illustrating an example implementation of an embodiment of detector station 30. In the example shown, detector station 30 includes two example detectors 31 and 37, as further described herein. For example, the detector in the form of an RFID transceiver device 31 is operable for reading RFID tags 117 affixed to vehicle 115.

[0022] More specifically, such as Figure 3 As shown, the RFID transceiver device 31 includes an RFID tag reader module 32 with a controller operatively connected to an antenna element 34, which is powered by the RFID tag reader module 32 to radiate RF energy (also referred to herein as a beam) on an antenna beamform. As those skilled in the art will recognize, the antenna and its beamform can be characterized by the antenna's beamwidth (i.e., the antenna's half-power beamwidth). Under the control of the RFID tag reader module 32, the RFID transceiver device 31 is operated to transmit RF beams or wave energy to the RFID tag 117 and to receive RF response signals (e.g., interrogation response signals) from the RFID tag 117, thereby interrogating and processing the payload of the RFID tag 117 within the reading range of the RFID transceiver device 31. During operation, the antenna element 34 can capture RFID tag information (e.g., vehicle identifier, RFID tag identifier, or other unique identifier) ​​corresponding to vehicles 115 crossing the highway 105.

[0023] In some embodiments, the controller 16 of the RFID detection system 112 configures the RFID tag reader module 32 based on instructions received via the I / O interface and / or in response to automatic determinations made at the RFID tag reader module 32. The RFID reading range of the detector station 30 can be a 360° area defined by the RFID antenna elements 34 and their combined beam pattern. In various embodiments, the detector station 30 may include eight RFID antenna elements 34, each held in a fixed position, and each having a beam pattern extending at a different angle relative to the detector station 30. In other embodiments, the detector station 30 may include a steerable (electronically and / or mechanically) phased array antenna to generate a beam pattern extending at a predetermined angle. In alternative embodiments, the RFID tag reader module 32 may also include a fully printed phase shifter and / or LC circuitry (inductor-capacitor resonant circuitry) to generate a beam at a specific angle relative to the detector station 30. More specifically, the RFID tag reader module 32 can be operatively connected to a weight memory 21 that stores multiple weight sets. When these weight sets are applied to signals going to / from the antenna element 34, they cause the transmitted / received signals to produce constructive interference relative to the detector station 30 at corresponding predetermined angles. It should be understood that the predetermined angles can include angles on both the azimuth and elevation axes. For example, in some embodiments, the beam covers a resolution of 10° elevation and 5° azimuth.

[0024] exist Figure 3 In the example shown, detector station 30 may also include a video detector 37 for detecting or locating vehicle 115 and / or RFID tag 117 by capturing images of lane 107. More specifically, the video detector 37 may be installed in each detector station 30 and may include a video module 40 having a camera controller connected to camera 42. Although Figure 3A video detector 37 is depicted mounted in detector station 30, but in some embodiments, the video detector 37 is located in a separate housing better configured to capture images of lane 107. In these embodiments, the video detector 37 is operatively connected to detector station 30. In some embodiments, camera 42 may be a high-bandwidth camera, such as a Moving Image Experts Group (MPEG) compressed camera. As described herein, the image capture device or camera (also referred to herein as an image sensor) is configured to capture image data representing the respective lane 107 and any vehicle 115 crossing lane 107. Furthermore, the image sensor described herein is an example data capture device, and the example methods and facilities described herein can be applied to any suitable type of data capture device. In various embodiments, the images or data from the images may be timestamped and synchronized or fused with other data (e.g., RFID data) and used to further describe vehicle 115 and / or highway 105 via the data. Such synchronized or fused data may be used, for example, by controller 16 to track vehicle use of highway 105.

[0025] Example detector station 30 is configured to enable RFID tag reader module 31 to perform interrogation cycles. In some embodiments, the interrogation cycle is defined by a plurality of indications that define, for example, one or more operating modes for RFID tag reader module 32, the dwell time spent by RFID tag reader module 32 in each operating mode, and / or when to broadcast queries and / or commands. To avoid cross-interference, the interrogation cycles of detector stations 30 can be synchronized with each other. For example, the interrogation cycles of detector stations 30a and 30c can be configured to interrogate RFID tags 117 in lanes 107a and 107c, respectively, during the time period when detector station 30b operates in standby mode. Similarly, the interrogation cycle of detector station 30b can be configured to interrogate RFID tags 117 in lane 107b during the time period when detector stations 30a and 30c operate in standby mode. RFID tag reader module 32 may include local memory storing indications defining the reading cycle.

[0026] As described above, improving the directionality of the beam generated by the RFID tag reader module 32 during the interrogation period improves the ability of the detector station 30 to interrogate the RFID tag 117, while reducing interference with adjacent detector stations 30. (Go to...) Figure 4The top and side views illustrate an example scenario where the RFID detection system 112 selects a specific beam 33 pointing towards the vehicle 115. As shown, the weight database 21 of the detector station 30 can be configured to store weight sets corresponding to beams 33a-33e, each of which is oriented at a different predetermined angle relative to the detector station 30 in azimuth and / or elevation.

[0027] As described above, controller 16 can be configured to receive frames of image data from video detector 37 of detector station 30. Controller 16 then analyzes the received frames of image data to detect the presence of vehicle 115 in the image data. For example, the controller can execute machine learning algorithms and / or rule-based algorithms to detect the presence of vehicle 115 in the frames of image data. For example, machine learning algorithms can be trained to detect portions of frames corresponding to vehicles. Because the positions of detector station 30 and / or video detector 37 are typically fixed, controller 16 can determine the relative position of vehicle 117 relative to detector station 30 based on the position of vehicle 115 in the image data. Using this relative position, controller 16 can identify a specific beam 33 pointing towards that relative position.

[0028] It should be understood that, given the relative size of the vehicle with respect to a typical beamwidth, multiple beams of the controller 30 can be directed to the relative position of the vehicle. For example, in Figure 4 In the example shown, controller 16 can determine the relative positions of beams 33b, 33c, and 33e pointing to the vehicle. Therefore, in order to select the most suitable beam 33 from the multiple beams pointing to the relative positions of the vehicle, controller 16 can perform additional analysis of frames of image data to identify specific features on which the RFID tag 117 of vehicle 115 may be located. For example, as in Figure 4 In the example shown, when the RFID tag 117 is affixed to the windshield of vehicle 115, the RFID tag 117 may be present in a frame of image data. Therefore, the controller 16 can execute an algorithm configured to detect the presence of the RFID tag 117 within the portion of the image data frame corresponding to vehicle 115. Figure 4 In the example shown, this analysis causes the controller 16 to select beam 33b, which is opposite to beams 33c and 33e. Upon determining that beam 33b is pointing to RFID tag 117, the controller 16 can cause the detector station 30 to perform an interrogation cycle using the weight set corresponding to beam 33b. More specifically, the controller 16 can configure the RFID tag reader module 32 of the detector station 30 to begin performing an interrogation cycle using the weight set corresponding to beam 33b.

[0029] In some embodiments, after selecting a specific beam 33, the controller 16 can control the RFID transceiver device 31 to make further adjustments to the beam pattern to increase the likelihood of reading the RFID tag 117 during an interrogation cycle. For example, the controller 16 can analyze frames of image data from the video detector 37 to determine the vehicle type (e.g., sedan, SUV, semi-truck, speedboat, yacht, or cruiser, etc.). Depending on the vehicle type, the controller 16 can adjust the beam height and / or beam width. For this purpose, when attempting to point the beam 33 at the windshield of a semi-truck, the controller 16 can increase the beam height. Similarly, in contrast to the license plate assembly, when attempting to point the beam 33 at the windshield, the controller 16 can adjust the beam width to be wider. As yet another example, if the controller 16 is able to detect the presence of the RFID tag 117 in a frame of image data, the controller 16 can adjust the beam height and / or width of the selected beam 33 to direct additional beam power toward the location of the RFID tag 117. To achieve changes in beam height and / or beamwidth, controller 16 may send a signal to RFID transceiver device 31 indicating adjustment coefficients (e.g., 0.75, 0.9, 1.1, 1.25, etc.), and RFID transceiver device 31 determines appropriate adjustments to the weight set in memory 21 to achieve the indicated changes in beam height and / or beamwidth.

[0030] In other scenarios, additional analysis may fail to detect the presence of the RFID tag 117 within the frame of image data. Therefore, controller 16 can perform additional analysis to detect features on which the RFID tag 117 of the vehicle may be located. For example, features could be the windshield and / or specific parts of the vehicle 115 (e.g., left, center, right), the license plate assembly of the vehicle 115, the roof and / or components on the vehicle 115, the roof and / or components on a trailer towed by the vehicle 115, and / or other locations known in the art. Controller 16 can then associate one or more features of the vehicle 115 with a corresponding beam 33 pointing to that feature. Therefore, controller 16 can cause controller 30 to perform a series of interrogation cycles rotating between weight sets corresponding to different features of the vehicle 115. That is, if no read event associated with the vehicle 115 is detected after a predetermined number of interrogation cycles (e.g., one, two, three, etc.), controller 16 can adjust the RFID transceiver device 31 to generate beams 33 pointing to different features of the vehicle 115.

[0031] In some embodiments, specific features of vehicle 115 can typically be classified based on the probability that RFID tag 117 is located at a specific feature of vehicle 115. Adjustments to the classification can be interpreted to account for the proximity of a feature to a higher-class feature (i.e., the probability that RFID tag 117 located at that feature will be interrogated by beam 33 pointing to a higher-class feature) and / or the type of vehicle 115. For example, an RFID tag 117 for a car is more likely to be located on the windshield, while an RFID tag 117 for a semi-truck is more likely to be located on the roof of the cab. As another example of a classification factor, controller 16 can determine the jurisdiction of the vehicle's home location (e.g., by analyzing image data of the vehicle's license plate) to identify any jurisdictional rules associated with the location of the RFID tag. Therefore, when controller 16 controls RFID transceiver device 31 to generate beams pointing to different features of vehicle 115, controller 16 can select a feature based on the determined feature classification. Given a limited time during which a vehicle 115 passes through a portion of lane 107 within the reading range of the RFID transceiver device 31, this tiered processing increases the likelihood of reading the RFID tag 117 while the vehicle 115 is passing through the reading range of the detector station 30.

[0032] After identifying vehicle 115 (and / or its features), controller 16 can continue tracking vehicle 115 using consecutive frames of image data received from video detector 37 of detector station 30. Based on the position of vehicle 115 in the consecutive frames of image data, controller 16 is able to estimate the vehicle's speed. Therefore, controller 16 can use the estimated speed of vehicle 115 to determine the expected relative position of vehicle 115 during future interrogation cycles, and select beam 33 based on this expected relative position, instead of controlling detector station 30 to use beam 33 currently pointing to the features of vehicle 115 and / or RFID tag 117. In some embodiments, the determination of the expected position also takes into account the processing delay caused by the image analysis techniques performed by controller 16. Therefore, any reference to selecting a beam pointing to the relative position of vehicle 115 also contemplates selecting a beam pointing to the expected relative position of vehicle 115. It should be understood that controller 16 can update the expected position of the tracked vehicle when additional frames of image data are received from video detector 37. In this way, even when vehicle 115 passes through the reading area of ​​detector station 30, detector station 30 can generate beam 33 pointing to the expected relative position of vehicle 115.

[0033] In some scenarios, controller 16 can determine that multiple vehicles 115 are located in the same lane 107 (e.g., Figure 1(Vehicles 115c and 115d). In some embodiments, controller 16 may cause detector station 30 to perform interrogation cycles that superimpose beams 33 pointing to the relative positions of the two vehicles. That is, to comply with maximum power requirements, the transmission power allocated to each beam may be scaled. For example, detector station 30 may allocate more transmission power to the beam pointing to the relative position of the closer vehicle, preferably considering vehicle 117 which will be located outside the readout area of ​​detector station 30 earliest. As another example, detector station 30 may allocate more transmission power to the beam pointing to the relative position of the more distant vehicle to address the increased distance from detector station 30. In other embodiments, to avoid power scaling, controller 16 may cause detector station 30 to alternate between interrogation cycles that point beam 33 to the relative position of the first vehicle and interrogation cycles that point beam 33 to the relative position of the second vehicle.

[0034] After controller 16 detects a read event associated with vehicle 115 (or more specifically, the RFID tag 117 associated with vehicle 115), controller 16 can update the records to track vehicle 115's use of highway 105. For example, if RFID detection system 112 is associated with a toll collection system, controller 16 notifies server 14 to collect the appropriate toll from the account associated with vehicle 115. As another example, if RFID detection system 112 is associated with a warehouse or other industrial environment, controller 16 can notify server 14 to ensure the vehicle is fulfilling its assigned task.

[0035] As part of updating the record, controller 16 can extract data included in the response of RFID tag 117 to include that data in the record. For example, in response to an interrogation signal transmitted by RFID transceiver device 31, RFID tag 117 can respond with an identifier that uniquely identifies vehicle 115 or RFID tag 117. Therefore, controller 16 can transmit a notification to server 14 indicating that the unique identifier is associated with a read event detected by RFID detection system 112. Server 14 can then identify the account associated with the unique identifier to update the corresponding record. In some embodiments, controller 16 can also include image data captured by video detector 37 in the notification sent to server 14 to ensure the accuracy of the read event. For example, controller 16 can extract image data representing the license plate of vehicle 115, allowing controller 16 or server 14 to apply optical character recognition (OCR) technology to ensure that the unique identifier obtained from RFID tag 117 matches the license plate indication in the record maintained at server 14.

[0036] After the controller 16 detects a read event associated with vehicle 115, the controller 16 may stop tracking vehicle 115 via video detector 37. Additionally, if vehicle 115 is so close to the edge of an image data frame that the RFID transceiver device 31 will not be able to query the RFID tag 117 in a subsequent interrogation cycle, the controller 16 may also stop tracking vehicle 115 via video detector 37. If the controller 16 detects that no vehicle is being tracked in lane 107 corresponding to detector station 30, the controller 16 may put the RFID transceiver device 31 of detector station 30 into standby mode until the controller 16 detects vehicle 115 in a frame of image data received from the video detector 37 of detector station 30. By putting the RFID transceiver device 31 into standby mode when vehicle 115 is not present, interference sensed by detector station 30 monitoring adjacent lanes 107 is reduced.

[0037] Now go to Figure 5 , Figure 5 A flowchart of an example method 500 for monitoring a highway (e.g., highway 105) using an RFID detection system (e.g., RFID detection system 112) is shown. The RFID detection system may include an image sensor (e.g., camera 42 of video detector 37) configured to have a field of view pointing towards a lane of the highway (e.g., lane 107). The RFID detection system may also include an RFID transceiver device (e.g., RFID transceiver device 31) configured to interrogate RFID tags (e.g., RFID tag 117) placed on vehicles (e.g., vehicle 115) within the lanes of the highway. In some embodiments, the RFID transceiver device includes an antenna array. In some embodiments, the image sensor and the RFID transceiver device are included in a detector station (e.g., detector station 30). The RFID detection system may also include a controller (e.g., controller 16) operatively connected to the image sensor and the RFID transceiver device and configured to perform the steps of example method 500.

[0038] Method 500 begins at block 502, where the controller causes the image sensor to capture frames of image data representing the lanes of the highway. For example, the controller may signal a video detector and / or a video module (e.g., video module 40) to begin capturing frames of image data via the image sensor. In this example, the video detector sends the captured frames of image data to the controller.

[0039] At box 504, the controller analyzes frames of image data to detect the presence of a vehicle in a highway lane. For example, the controller may execute an algorithm (e.g., a rule-based algorithm or a trained machine learning algorithm) to identify the presence of a vehicle in the frames of image data. In some embodiments, upon detecting the presence of a vehicle, the controller begins tracking the vehicle across multiple frames of image data received from the image sensor.

[0040] At box 506, based on this analysis, the controller determines the vehicle's position relative to the RFID transceiver device (and / or the detector station including the RFID transceiver device). In an embodiment that tracks the vehicle across multiple frames of image data, the controller may compare the vehicle's position across the multiple frames of image data to estimate the vehicle's speed. Based on the estimated vehicle speed, the controller then predicts the vehicle's position relative to the RFID transceiver device for subsequent interrogation cycles of the RFID transceiver device. In other words, the controller can determine the predicted or anticipated relative position of the vehicle.

[0041] At block 508, the controller configures the antenna array to generate a beam pointing towards the vehicle's location. In embodiments where the vehicle is tracked across multiple frames of image data, the vehicle's location is a predicted or anticipated location. In some embodiments, the RFID transceiver device includes multiple predetermined gain spectra (e.g., a set of weights stored in a memory such as weight memory 21) respectively configured to generate a beam pointing from the antenna array at a predetermined angle. Thus, based on the vehicle's location, the controller can determine the angle at which the vehicle is positioned relative to the RFID transceiver device and select a gain spectrum from the multiple gain spectra corresponding to the determined angle. In any case, to configure the antenna array, the controller can instruct the RFID transceiver device to use the selected gain spectrum when performing an interrogation cycle.

[0042] In some embodiments, the controller may configure the antenna array to more specifically direct a beam toward the RFID tag affixed to the vehicle. Thus, the controller can identify a predetermined location of the vehicle where the RFID tag may be located, and the controller may configure the antenna array to generate a beam that is directed toward the predetermined location of the vehicle. In this embodiment, the controller may determine that no read event corresponding to the RFID tag affixed to the vehicle has occurred within a threshold number of interrogation periods, and configure the antenna array to generate a beam directed toward a second predetermined location of the vehicle. Alternatively, the controller may analyze frames of image data to identify the RFID tag affixed to the vehicle, where the RFID tag comprises an RFID tag, and the controller may configure the antenna array to generate a beam that is directed toward the RFID tag. In either case, the controller may adjust the height or width of the beam to ensure that the RFID tag and / or vehicle features are better positioned within the shape of the beam. In some embodiments, the adjustment of the beam height or width is based on the vehicle type.

[0043] In some scenarios, the controller detects the presence of two or more vehicles located in a lane of a highway based on the analysis of frames of image data. In some embodiments, the controller configures the gain spectrum of the antenna array to include peaks pointing to each of the two or more vehicles. In other embodiments, the controller configures the antenna array to generate a beam pointing to the location of a first vehicle among the two or more vehicles during a first interrogation period of the RFID transceiver device; and to generate a beam pointing to the location of a second vehicle among the two or more vehicles during a second interrogation period of the RFID transceiver device.

[0044] In some embodiments, the controller detects a response to an interrogation signal included in the generated beam. For example, the response may include an identifier associated with at least one of the vehicle and its RFID tag. In the response, the controller may analyze frames of image data to identify the vehicle's license plate and transmit a notification communicatively coupled to a server of the RFID detection system, the notification including indication of the identifier and indication of the license plate. In some embodiments, the indication of the license plate is a portion of the image data frame corresponding to the license plate.

[0045] To reduce interference in embodiments including multiple detector stations, where each detector station includes a corresponding RFID transceiver device configured to query RFID tags on vehicles in corresponding lanes of a highway, a controller can be configured to synchronize a first query cycle performed by a first RFID transceiver device and a second query cycle performed by a second RFID transceiver device (e.g., an adjacent detector station). During the first query cycle, the RFID transceiver device of the first detector station is configured to query RFID tags in the first lane of the highway, and the second RFID transceiver device of the second detector station operates in standby mode. Similarly, during the second query cycle, the controller configures the first RFID transceiver device to operate in standby mode and the second RFID transceiver device to query RFID tags in the second lane of the highway. If RFID detection includes a third detector station located on the opposite side of the second detector station, the controller can configure the RFID transceiver device of the third detector station to query RFID tags in the third lane of the highway during the first query cycle and to operate in standby mode during the second query cycle.

[0046] The above description relates to the block diagrams in the accompanying drawings. Alternative implementations of the examples represented by the block diagrams include one or more additional or alternative elements, processes, and / or devices. Additionally or alternatively, one or more of the example blocks in the schematic diagrams may be combined, divided, rearranged, or omitted. Components represented by the blocks in the schematic diagrams are implemented by hardware, software, firmware, and / or any combination of hardware, software, and / or firmware. In some examples, at least one of the components represented by the blocks is implemented by logic circuitry. As used herein, the term "logic circuitry" is explicitly defined as a physical device comprising at least one hardware component configured to control one or more machines and / or perform operations on one or more machines, for example, via operation according to a predetermined configuration and / or via execution of stored machine-readable instructions. Examples of logic circuitry include one or more processors, one or more coprocessors, one or more microprocessors, one or more controllers, one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), one or more microcontroller units (MCUs), one or more hardware accelerators, one or more application-specific computer chips, and one or more system-on-a-chip (SoC) devices. Some example logic circuits (e.g., ASICs or FPGAs) are hardware with a specific configuration for performing operations (e.g., one or more operations described herein and represented by flowcharts of this invention, if such operations exist). Some example logic circuits are hardware that executes machine-readable instructions to perform operations (e.g., one or more operations described herein and represented by flowcharts of this invention, if such operations exist). Some example logic circuits include a combination of hardware with a specific configuration and hardware that executes machine-readable instructions. The above description relates to various operations described herein and flowcharts that may be appended to illustrate these operations. Any such flowchart represents an example method disclosed herein. In some examples, the method represented by the flowchart applies facilities represented by the block diagram. Alternative implementations of the example methods disclosed herein may include additional or alternative operations. Furthermore, operations of alternative implementations of the methods disclosed herein may be combined, divided, rearranged, or omitted. In some examples, the operations described herein are implemented by machine-readable instructions (e.g., software and / or firmware) stored on a medium (e.g., a tangible machine-readable medium) for execution by one or more logic circuits (e.g., a processor). In some examples, the operations described herein are implemented by one or more configurations of one or more specially designed logic circuits (e.g., ASICs). In some examples, the operations described herein are implemented by a combination of specially designed logic circuits and machine-readable instructions stored on a medium (e.g., a tangible machine-readable medium) for execution by the logic circuits.

[0047] As used herein, each of the terms "tangible machine-readable medium," "non-transient machine-readable medium," and "machine-readable storage device" is explicitly defined as a storage medium (e.g., a hard disk platter, digital versatile optical disc, compact optical disc, flash memory, read-only memory, random access memory, etc.) on which machine-readable instructions (e.g., program code in the form of software and / or firmware) are stored for any suitable duration (e.g., permanently, for a long period of time (e.g., while a program associated with the machine-readable instructions is being executed), and / or for a short period of time (e.g., when the machine-readable instructions are cached and / or during a buffering process)). Furthermore, as used herein, each of the terms "tangible machine-readable medium," "non-transient machine-readable medium," and "machine-readable storage device" is explicitly defined to exclude the propagation of signals. That is, as used in any claim of this patent, the terms "tangible machine-readable medium," "non-transient machine-readable medium," and "machine-readable storage device" should not be construed as being implemented by the propagation of signals.

[0048] Specific embodiments have been described in the foregoing specification. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the invention as set forth in the following claims. Therefore, the specification and drawings are to be considered illustrative rather than restrictive, and all such modifications are intended to be included within the scope of the invention. Furthermore, the described embodiments / examples / implementations should not be construed as mutually exclusive, but rather as potentially combinable if such combinations are permitted in any way. In other words, any feature disclosed in the foregoing embodiments / examples / implementations can be included in any other foregoing embodiments / examples / implementations.

[0049] Benefits, advantages, solutions to problems, and any elements that may produce or make more significant any benefit, advantage, or solution shall not be construed as key, essential, or necessary features or elements of any or all claims. The claimed invention is defined solely by the appended claims, which include any modifications made during the pending period of this application and all equivalents of those claims.

[0050] Furthermore, in this invention, relational terms such as first and second, top and bottom, etc., can be used merely to distinguish one entity or action from another, without necessarily requiring or implying any actual such relationship or order between these entities or actions. The term "including"

[0051] The terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” “contains,” “containing,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or facility that includes, has, contains, or contains a list of elements not only includes those elements but may also include other elements not expressly listed or inherent to such process, method, article, or facility. Without further limitation, elements beginning with “comprises…a,” “has…a,” “includes…a,” or “contains…a” do not exclude inclusion, having, containing, or containing of other elements. The process, method, article, or facility containing this element contains additional identical elements. The terms "a" and "an" are defined as one or more unless explicitly stated otherwise herein. The terms "substantially," "basically," "about," "approximately," or any other form thereof are defined as close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment, the term is defined as within 10%, in another within 5%, in yet another within 1%, and in yet another within 0.5%. The term "coupled" as used herein is defined as connected, although not necessarily a direct connection or a mechanical connection. A device or structure "configured" in a certain way is configured at least in this manner, but may also be configured in ways not listed.

[0052] An abstract of the invention is provided to allow readers to quickly determine the nature of the technical disclosure. This abstract should be understood not to be construed as limiting the scope or meaning of the claims. Furthermore, as can be seen in the foregoing detailed description, various features are combined in various embodiments for the purpose of simplifying the invention. The method of the invention should not be construed as reflecting an intention to require more features than expressly recited in each claim. Rather, as reflected in the following claims, the inventive subject matter may be less than all the features of a single disclosed embodiment. Therefore, the appended claims are thereby incorporated into the detailed description, wherein each claim is independently claimed as a separate subject matter.

Claims

1. A radio frequency identification (RFID) detection system for monitoring highways, the RFID detection system comprising: An image sensor is configured to have a field of view pointing towards the lanes of the highway. An RFID transceiver device configured to query RFID tags on vehicles located in lanes of the highway, wherein the RFID transceiver device includes an antenna array. as well as A controller, operably connected to the image sensor and the RFID transceiver device, wherein the controller is configured to: The image sensor captures frames of image data representing the lanes of the highway; Analyze the frames of the image data to detect the presence of vehicles in the lanes of the highway; Based on the analysis, the position of the vehicle relative to the RFID transceiver device is determined; as well as By identifying that the RFID tag is located at a predetermined location on the vehicle, and configuring the antenna array to generate a beam that is directed towards the predetermined location on the vehicle, the antenna array is configured to generate a beam that is directed towards the determined location on the vehicle. In order to configure the antenna array to generate a beam pointing towards the predetermined location of the vehicle, the controller is configured to: The location of the vehicle at the predetermined position is determined based on the vehicle type of the vehicle; as well as Adjust the height or width of the beam based on the determined location.

2. The RFID detection system according to claim 1, wherein: The RFID transceiver device includes a plurality of predetermined gain spectra, each of which is configured to generate a beam pointing from the antenna array to a predetermined angle. as well as The antenna array is configured to generate a beam directed at the location of the vehicle, and the controller is configured to: Based on the vehicle's position, the angle at which the vehicle is positioned relative to the RFID transceiver device is determined, and Select the gain spectrum corresponding to the determined angle from multiple gain spectra.

3. The RFID detection system according to claim 1, wherein, The controller is configured to use machine learning algorithms to detect the presence of the vehicle.

4. The RFID detection system according to claim 1, wherein, The predetermined location of the vehicle is one of the windshield, license plate assembly, and roof.

5. The RFID detection system according to claim 1, wherein, In order to configure the antenna array to generate a beam pointing towards the location of the vehicle, the controller is configured to: Analyze the frames of the image data to identify the RFID tags affixed to the vehicle; as well as The antenna array is configured to generate the beam such that the beam is directed at the RFID tag.

6. The RFID detection system according to claim 5, wherein, In order to configure the antenna array to generate a beam directed at the RFID tag, the controller is configured to: Determine the position of the RFID tag relative to the vehicle; and The height or width of the beam is adjusted based on the relative position.

7. The RFID detection system according to claim 1, wherein, In order to analyze the image dataset to detect the presence of vehicles, the controller is configured to: Detect the presence of two or more vehicles located in a lane of the highway.

8. The RFID detection system according to claim 7, wherein, In order to configure the antenna array to generate a beam pointing towards the location of the vehicle, the controller is configured to: The gain spectrum of the antenna array is configured to include peaks pointing to each of the two or more vehicles.

9. The RFID detection system according to claim 7, wherein, In order to configure the antenna array to generate a beam pointing towards the location of the vehicle, the controller is configured to: The antenna array is configured to generate a beam pointing to the location of the first of the two or more vehicles during the first interrogation period of the RFID transceiver device. as well as The antenna array is configured to generate a beam pointing to the location of the second of the two or more vehicles during the second interrogation period of the RFID transceiver device.

10. The RFID detection system according to claim 1, wherein: The controller is configured to select a predetermined location of the vehicle from two or more predetermined locations of the vehicle; as well as The antenna array is configured to generate a beam directed at the location of the vehicle, and the controller is configured to: The antenna array is configured to generate a beam pointing toward the vehicle's location based on a first predetermined location among the two or more predetermined locations; It is determined that no reading event corresponding to the RFID tag affixed to the vehicle occurred within a threshold number of query cycles; as well as In response to the determination, the antenna array is configured to generate a beam pointing toward the vehicle's location based on a second predetermined location among the two or more predetermined locations.

11. The RFID detection system according to claim 1, wherein, In order to configure the antenna array to generate a beam pointing towards the location of the vehicle, the controller is configured to: Track the vehicle across multiple frames of image data; as well as The vehicle's position is compared across multiple frames of image data to estimate the vehicle's speed; Predict the vehicle's position relative to the RFID transceiver device for subsequent interrogation cycles of the RFID transceiver device; and The beam is generated such that it is pointed to the predicted location of the vehicle during subsequent interrogation periods.

12. The RFID detection system according to claim 1, wherein: The lane of the highway is the first lane of the highway. The RFID transceiver device is the first RFID transceiver device; as well as The RFID detection system also includes: A second RFID transceiver device is configured to query RFID tags on vehicles located in the second lane of the highway, wherein the second RFID transceiver device includes a second RFID array.

13. The RFID detection system according to claim 12, wherein, The controller is configured to: Synchronize the first interrogation cycle executed by the first RFID transceiver device with the second interrogation cycle executed by the second RFID transceiver device, such that: During the first interrogation period, the first RFID transceiver device is configured to interrogate RFID tags in the first lane of the highway, and the second RFID transceiver device operates in standby mode. as well as During the second interrogation period, the first RFID transceiver device operates in standby mode, and the second RFID transceiver device is configured to interrogate RFID tags in the second lane of the highway.

14. The RFID detection system according to claim 13, further comprising: A third RFID transceiver device is configured to query RFID tags on vehicles located in the third lane of the highway, wherein (i) the third RFID transceiver device includes a third antenna array, and (ii) a second RFID transceiver device is disposed between the first RFID transceiver device and the third RFID transceiver device. In order to synchronize the first query cycle with the second query cycle, the controller is configured to: Control the third RFID transceiver device to query the RFID tags in the third lane of the highway during the first query period; as well as The third RFID transceiver device is controlled to operate in standby mode during the second interrogation period.

15. The RFID detection system according to claim 1, wherein, The controller is configured to: The detection responds to an interrogation signal included in the generated beam, the response including an identifier associated with at least one of the vehicle and the vehicle's RFID tag; Analyze the frames of the image data to identify the vehicle's license plate; A notification is transmitted to a server communicatively coupled to the RFID detection system, the notification including an indication of the identifier and an indication of the license plate.

16. The RFID detection system according to claim 15, wherein, The license plate indication is part of a frame representing the image data of the vehicle.

17. A method for monitoring highways using a radio frequency identification (RFID) detection system, the RFID detection system comprising: (i) an image sensor configured to have a field of view pointing toward the lanes of the highway; (ii) An RFID transceiver device configured to query RFID tags on vehicles located in the lanes of the highway, wherein the RFID transceiver device includes an antenna array. and (iii) a controller operably connected to the image sensor and the RFID transceiver device, the method comprising: The controller causes the image sensor to capture frames of image data representing the lanes of the highway; The controller analyzes frames of the image data to detect the presence of vehicles in the lanes of the highway. Based on the analysis, the controller determines the position of the vehicle relative to the RFID transceiver device; and By identifying that the RFID tag is located at a predetermined location on the vehicle, and configuring the antenna array to generate a beam pointing towards the predetermined location on the vehicle, the controller configures the antenna array to generate a beam pointing towards the determined location on the vehicle, wherein... Configuring the antenna array to generate a beam directed at the predetermined location of the vehicle includes: The controller determines the location of the vehicle at the predetermined position based on the vehicle type; and Based on the determined location, the height or width of the beam is adjusted by the controller.

18. The method of claim 17, wherein: The RFID transceiver device includes multiple predetermined gain spectra, each of which is configured to generate a beam pointing from the antenna array to a predetermined angle. as well as Configuring the antenna array to generate a beam pointing towards the location of the vehicle includes: Based on the vehicle's position, the controller determines the angle of the vehicle relative to the RFID transceiver device, and The controller selects the gain spectrum corresponding to the determined angle from the plurality of gain spectra.

19. The method of claim 17, wherein, Configuring the antenna array to generate a beam pointing towards the location of the vehicle includes: The controller analyzes frames of the image data to identify RFID tags affixed to the vehicle; and The controller configures the antenna array to generate the beam so that the beam is directed at the RFID tag.

20. The method of claim 17, wherein, Configuring the antenna array to generate a beam pointing towards the location of the vehicle includes: The controller detects the presence of two or more vehicles located in the lane of the highway. The controller configures the gain spectrum of the antenna array to include peaks pointing to each of the two or more vehicles.

21. The method according to claim 17, wherein, Configuring the antenna array to generate a beam pointing towards the location of the vehicle includes: The controller detects the presence of two or more vehicles located in the lane of the highway. The controller configures the antenna array to generate a beam pointing to the location of the first of the two or more vehicles during the first interrogation period of the RFID transceiver device; and The controller configures the antenna array to generate a beam pointing to the location of the second of the two or more vehicles during the second interrogation period of the RFID transceiver device.

22. The method according to claim 17, wherein, Configuring the antenna array to generate a beam pointing towards the location of the vehicle includes: The controller configures the antenna array to generate a beam pointing toward the vehicle based on a first predetermined position among two or more predetermined positions. The controller determines that no reading event corresponding to the RFID tag affixed to the vehicle has occurred within a threshold number of interrogation cycles; and In response to the determination, the controller configures the antenna array to generate a beam pointing toward the vehicle's location based on a second predetermined location among the two or more predetermined locations.

23. The method of claim 17, wherein, Configuring the antenna array to generate a beam pointing towards the location of the vehicle includes: The controller tracks the vehicle across multiple frames of image data; and The controller compares the vehicle's position across multiple frames of image data to estimate the vehicle's speed. The controller predicts the vehicle's position relative to the RFID transceiver device for subsequent interrogation cycles of the RFID transceiver device; and The controller generates a beam that is directed to the predicted location of the vehicle during subsequent interrogation periods.

24. The method of claim 17, wherein: The lane of the highway is the first lane of the highway. The RFID transceiver device is a first RFID transceiver device; and The RFID detection system further includes a second RFID transceiver device configured to query RFID tags on vehicles located in the second lane of the highway, wherein the second RFID transceiver device includes a second RFID array. The method further includes: The controller synchronizes the first interrogation cycle executed by the first RFID transceiver device with the second interrogation cycle executed by the second RFID transceiver device, such that: During the first interrogation period, the first RFID transceiver device is configured to interrogate RFID tags within the first lane of the highway, and the second RFID transceiver device operates in standby mode; and During the second interrogation period, the first RFID transceiver device operates in standby mode, and the second RFID transceiver device is configured to interrogate RFID tags in the second lane of the highway.

25. The method according to claim 17, further comprising: The controller detects a response to an interrogation signal included in the generated beam, the response including an identifier associated with at least one of the vehicle and the vehicle's RFID tag; The controller analyzes frames of the image data to identify the vehicle's license plate. A notification is transmitted to a server communicatively coupled to the RFID detection system, the notification including an indication of the identifier and an indication of the license plate.

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