CN105022095A - Quick-pass-type moving target radiation inspection method and system - Google Patents

Abstract

The invention discloses a speed-through type radiation inspection method for a moving target, comprising: acquiring the length K of the part of the moving target that needs radiation avoidance; acquiring the moving speed V of the moving target in the detection channel; based on the length K and the moving speed V, Determine the time T when the part of the moving target that needs radiation avoidance completely passes through the radiation inspection position; when the time T arrives, emit rays at the radiation inspection position for radiation inspection; stop emitting rays after the moving target leaves the radiation inspection position. The invention also provides a speed-through radiation inspection system for moving objects. The invention can dynamically adjust the beam emitting timing of the radiation source.

Description

Method and system for speed-passing radiation inspection of moving targets

technical field

The invention relates to the technical field of radiation scanning, in particular to a speed-through radiation inspection method and system for a moving target.

Background technique

At present, high-energy radiation devices are used to scan and inspect high-speed moving targets such as vehicles, and the scanning can be completed without interrupting the passage of vehicles. Significance. During the radiation scanning inspection process, in order to ensure the personal safety of the personnel, it is necessary to partially avoid the target moving object. For example, when scanning the radiation of a moving vehicle, it is necessary to wait for the driver's cab to pass the radiation source before proceeding to release the beam. Scanning is performed only on the portion of the wagon that contains the cargo.

At present, the methods that can be adopted for the radiation scanning inspection of moving targets are as follows: 1. The sensor assembly is set to sense the gap between the first part and the second part of the moving target. Control the propagation of high-energy rays to avoid the first part of the moving target; second, set up detection components downstream of the radiation source to detect that the cab has passed the scanning position but the carriage has not yet reached the scanning position, and then the beam can be used to avoid the cab personnel.

However, after a lot of research and analysis, it is found that although these schemes can achieve the purpose of inspection, there are many defects. For the first method, it is necessary to sense the gap between the first part and the second part of the moving target, but in many cases there is no gap or the gap is not clear between the first part and the second part of the moving target, and this method will not be able to judge the second part. One part reaches the inspection position, causing the second part to fail to scan normally. For the second method, the position of the detection part and the radiation source is fixed, but the length of the radiation-avoiding part (such as the cab) needs to be changed in practical applications, which may easily lead to missed inspections of the compartment or false scanning of the cab personnel, and the security inspection results are reliable. Low safety, great radiation safety hazard.

Contents of the invention

In view of this, the present invention provides a speed-through radiation inspection method and system for moving targets. By rationally arranging the detectors and dynamically adjusting the timing of the radiation source beam output, on the premise of ensuring the reliability of the radiation inspection results, the inspection of personnel is realized. 100% dodge.

On the one hand, the present invention provides a speed-through radiation inspection method for a moving target, comprising: obtaining the length K of the part of the moving target that needs radiation avoidance; obtaining the moving speed V of the moving target in the detection channel; based on the length K and the moving speed V, determine the time T when the part of the moving target that needs radiation avoidance completely passes through the radiation inspection position; when the time T arrives, emit rays at the radiation inspection position for radiation inspection; stop emitting rays after the moving target leaves the radiation inspection position.

Preferably, the moving speed of the moving target V=(L1-L2)/(t2-t1), wherein L1 and L2 are respectively the distances from the first position and the second position in the detection channel to the radiation inspection position, and the first position and the second position are located on the upstream side of the radiation inspection position, and L1>L2; t1 and t2 are the moments when the moving target reaches the first position and the second position respectively; the time when the head of the moving target reaches the second position is taken as the reference time , the time T is later than the reference time by the first time interval T1=(K+L2)/V.

Preferably, after the moving target leaves the radiation inspection position, and after a second time interval has elapsed since the tail of the moving target leaves the second position, stop emitting rays, the second time interval T2=b*L2/V, where b is greater than or equal to 1 constant.

Preferably, if the moving object decelerates after reaching the second position, the method further includes: when the head of the moving object does not reach the third position after reaching the second position and after a third time interval, then not A ray is emitted; wherein, the third position is located on the downstream side of the radiation inspection position, the distance from the third position to the radiation inspection position is L3, and L3 is less than or equal to the length K', where K' is the length of the part that needs radiation avoidance among various moving targets The minimum value of the length; the third time interval is T3=a(L2+L3)/V, where a is a constant greater than or equal to 1.

Preferably, if the moving target decelerates after reaching the second position, when the head of the moving target does not reach the third position after reaching the second position and after a third time interval, no rays are emitted when the time T arrives, the method furthermore Including: Sending a ray when moving the target's head to the third position.

Preferably, when the tail of the moving target leaves the third position, the emission of rays is stopped.

Preferably, taking the moment when the head of the moving target reaches the fourth position in the detection channel as the reference moment, the moment T is later than the fourth time interval of the reference moment, and the fourth time interval T4=(K+L4)/V; where the fourth The location is located on the upstream side of the radiation inspection location, at a distance of L4 from the radiation inspection location.

On the other hand, the present invention also provides a speed-through radiation inspection system for a moving target, including: a radiation imaging device, used to emit rays to scan the moving target and generate a radiation image; a moving target information acquisition device, used to acquire the moving target The length K of the part that needs radiation avoidance; the moving speed acquisition device is used to obtain the moving speed V of the moving target in the detection channel; the radiation moment determination device is used to determine the radiation imaging device based on the length K and the moving speed V The time T when the radiation is emitted; the radiation control device is used to control the radiation imaging device to emit radiation at the radiation inspection position for radiation inspection when the time T arrives, and stop emitting the radiation after the moving target leaves the radiation inspection position.

Beneficial effects of the present invention: the present invention dynamically adjusts the beam output timing of the radiation source by rationally arranging the number and position of the detectors, detecting the speed of the moving target and the length of the part that needs radiation avoidance, and realizes the reliability of the radiation inspection results. Under the premise of 100% avoidance of personnel, to ensure the safety of personnel.

Description of drawings

Fig. 1 is a flow chart of a speed-through radiation inspection method for a moving target according to an embodiment of the present invention.

Fig. 2 is a diagram of the use status of the speed-through radiation inspection system for moving objects according to the embodiment of the present invention.

Fig. 3 is a top view of the embodiment of Fig. 2 .

Fig. 4 is a diagram of the use status of the speed-through radiation inspection system for moving objects according to another embodiment of the present invention.

Fig. 5 is a diagram of the use status of the speed-through radiation inspection system for moving objects according to another embodiment of the present invention.

FIG. 6 is a side view of the embodiment of FIG. 5 .

Fig. 7 is a flowchart of a speed-through radiation inspection method for a moving target according to another embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 shows the flow chart of the speed-through radiation inspection method for moving objects according to the embodiment of the present invention, which can be used in the radiation scanning detection occasions of various moving objects, and Fig. 2 shows the work of the radiation inspection system in one embodiment of the present invention State diagram, FIG. 3 is a top view of the embodiment in FIG. 2 , and this embodiment is described by taking the security check of the moving object, namely the truck 10 , as an example.

Referring to Figures 1-3, in this embodiment, the equipment cabin 1 and the radiation detector 2 are respectively placed on both sides of the detection channel, and a radiation source 1A, a radiation source shield 1B and a radiation beam collimator 1C are arranged in the equipment cabin 1, and the radiation The rays emitted by the source are collimated by the radiation beam collimation 1C and then output the beam. The truck 10 travels along the detection channel, and scans and inspects when passing the beam output position. The radiation passes through the truck 10 and is received by the radiation detector 2 for scanning image imaging, etc. deal with. In order to ensure the safety of personnel, during the radiation inspection process, the cab 12 where the driver is located is a part that needs radiation avoidance. In order to reduce the amount of radiation leaked from the system, radiation shielding facilities 5 can be installed within a certain space around the system equipment and the security inspection channel.

The radiation inspection system of the present invention includes a control module (not shown in the figure), which receives signals from a plurality of detectors and controls the beam emitting timing of the radiation source. The detectors can be photoelectric switches, light curtains, ground sensing coils, axle load sensors, etc., or a combination of these sensors; the detectors can be arranged above or below the ground of the passage. Concretely to this example, the detectors 20 and 30 are light curtains, both located on the upstream side of the scanning position (the left side in the figure). The distance from the detector 20 to the scanning position is L1, and the distance from the detector 30 to the scanning position is L2.

In addition, a ground induction coil can be installed on the left side (upstream side) of the detector 30. Since the ground induction coil can only be triggered by a metal object, it can be used as an auxiliary detector of the detector 30. Only when the ground induction coil is triggered, Detector 30 triggers to be effective. This measure can effectively prevent errors in determining the radiation time caused by other non-metallic objects (such as people, birds, foreign objects, etc.) entering the inspection channel by mistake.

During the security inspection, the truck 10 is driving in the detection channel, and the front of the truck triggers the detectors 20 and 30 one after another, and the control module obtains the time difference ΔT=t2-t1 according to the two triggering moments, where t1 and t2 are respectively the detector 20 and the detector 30 are detected by the truck. 10 is triggered, and then calculate the running speed V=(L1-L2)/ΔT of the truck 10. Assuming that the length of the cab 12 of the truck 10 is K, then after the detector 30 is triggered (i.e. the reference moment), after a time delay of T1=(K+L2)/V, the control radiation source starts to emit rays for scanning, because after T1 =(K+L2)/V The rear cab 12 has completely passed the scanning position. At this time, the emitted ray only scans the rear compartment part of the truck 10, so as to realize 100% avoidance of the cab (driver).

In the embodiment of the present invention, the vehicle identification device can be used to acquire the relevant information of the part of the moving target that needs to be avoided. In the embodiment shown in Fig. 2 and Fig. 3, a license plate recognition device is installed on the upstream side of the detector 20, including a camera 5A, a light curtain sensor 5B, a ground induction coil 5C and corresponding control recognition software. After using the license plate recognition device to obtain the vehicle license plate information, the vehicle model and cab size and other information can be obtained from the vehicle information database storage. If the vehicle type is a vehicle type (such as a passenger car) that prohibits radiation inspection, the control module will not allow the radiation to be emitted, that is, the entire vehicle is considered to be a cab; if the vehicle type is a vehicle type that allows radiation inspection (such as a truck), the length of the cab The parameters are sent to the control module of the radiation inspection system. Since the license plate recognition device needs a certain amount of time to complete the license plate recognition, database retrieval and communication with the radiation inspection system, it is advisable to install the license plate recognition device at a distance of 10-20 meters from the detector 20 .

In the embodiment of the present invention, non-contact identification devices such as RFID identification devices, barcode identification devices, and two-dimensional code identification devices can also be used to obtain the types of various moving objects and the length parameters of the parts that need to be avoided.

In the embodiment of the present invention, the radiation inspection system can also be provided with a vehicle parameter information input module, and the operator can input the length parameter of the cab of the vehicle to be inspected into the system control module. In addition, the length parameters of the cab can also be preset in the radiation inspection system, which is suitable for situations where the identity of the vehicle cannot be identified, the corresponding vehicle information is lacking in the database, or the vehicle type is similar to the inspection.

Fig. 4 is a diagram of the usage status of the radiation inspection system according to another embodiment of the present invention. A detector 40 is installed on the downstream side of the scanning position, and is used for the auxiliary control module to control the beam output timing of the radiation source when the truck 10 decelerates. The detector 40 is installed at a position L3 away from the scanning position, and the length of L3 should not be greater than the length of the smallest cab among various vehicles that may appear. During the security check, after the detector 30 is triggered, if the detector 40 is not triggered within the time a(L2+L3)/V, it means that the vehicle has decelerated, and the coefficient a is not less than 1, for example, a=1.2 means that the vehicle is allowed Decelerate but the minimum speed is V(1/1.2). When the speed is lower than this value, the vehicle will not trigger the detector 40 within the time a(L2+L3)/V. Safe, the control module will disable the radiation source from emitting radiation beams. Optionally, after the detector 30 is triggered, wait for the detector 40 to be triggered, and then make the radiation source start emitting radiation beams.

Fig. 5 is a diagram showing the state of use of the radiation inspection system according to another embodiment of the present invention. Fig. 6 is a side view of the embodiment in Fig. 5. In this embodiment, a radar speed measuring device 50 is used to detect the moving speed V of a moving target, and a detector 60 is installed in conjunction with it. Determine the moment when the radiation source starts emitting radiation. Specifically, the radar speed measuring device 50 can be installed on the downstream side of the scanning position, the installation height is not lower than the allowed maximum height of the object to be inspected, and it is separated from the detector 60 by an appropriate distance. The detector 60 is installed upstream of the scanning position at a distance L4 from the scanning position.

When the truck 10 is running in the detection channel, the speed measuring radar device 50 measures its speed, and the moving speed value V of the truck 10 can be obtained directly. Assuming that the length of the cab 12 of the truck 10 is K, after the detector 60 is triggered by the front of the truck, it should be After the time delay T4=(K+L4)/V, the control radiation source starts to emit rays and scans, because the driver's cab 12 has completely passed the scanning position through T4=(K+L4)/V, and now the rays are only for the truck 10. The trunk section is scanned.

In the embodiment shown in Figures 5 and 6, the radar speed measuring device 50 uses the Doppler effect of electromagnetic waves to detect the moving speed of the target by detecting the frequency change of the electromagnetic wave reflected by the object, and is widely used in traffic engineering to detect the speed of vehicles, such as " Spark" radar speedometer. In addition, instruments such as laser velocimeter or visual velocimeter can also be used to obtain the moving speed of the moving target.

7 is a logical block diagram of the radiation inspection method of the embodiment of the present invention, specifically as follows: use the vehicle identification device to capture the identity information of the vehicle to be inspected, retrieve the vehicle information database according to the vehicle identity information, and determine the length of the cab of the vehicle to be inspected (if there is no retrieval To the corresponding data, you can manually input or use the system preset parameters).

After the vehicle triggers the detector 20, the control module determines the time to start the scan according to the detected vehicle moving speed and the time when the detector 30 is triggered, and when the scan time arrives, a scan start command is given, and the radiation source emits rays for scanning .

When the rear of the vehicle leaves the detector 30 (i.e. the detector 30 recovers from the triggered state to the untriggered state), the whole vehicle leaves the scanning position after a delay of b*L2/V, and the control module gives a scanning end command, and the coefficient b is greater than or equal to 1. Optionally, a scan end command can also be given when the rear of the vehicle leaves the detector 40 .

The above embodiments of the present invention are based on the use of a transmission scanning radiation imaging system, which includes radiation sources, radiation beam collimation and shielding, radiation safety facilities, radiation detectors, image acquisition and processing systems, and the like. It should be noted that since the present invention mainly realizes personnel avoidance by calculating the time when the radiation beam is emitted, there is no special requirement for radiation sources and radiation imaging equipment, so the present invention is not only applicable to transmission scanning radiation imaging systems, but also applicable to Other forms of radiation imaging systems, such as backscatter radiation imaging systems, forward scatter radiation imaging systems, etc.

The invention realizes the intelligent avoidance of the parts to be protected in the inspected object, has high avoidance precision and good safety, and is the best way to automatically and quickly scan and inspect different types of moving objects containing the parts to be protected.

Above, the technical solution of the present invention has been introduced in detail in conjunction with specific embodiments, and the described specific embodiments are used to help understand the idea of the present invention. Derivations and modifications made by those skilled in the art on the basis of the specific embodiments of the present invention also fall within the protection scope of the present invention.

Claims (20)

1. A speed-through type mobile target radiation inspection method, characterized in that, comprising: Obtain the length K of the part of the moving target that needs radiation avoidance; Obtain the moving speed V of the moving target in the detection channel; Based on the length K and the moving speed V, determine the moment T when the part of the moving target that needs radiation avoidance completely passes through the radiation inspection position; When time T arrives, emit radiation at the radiation inspection position for radiation inspection; Stop emitting rays after the moving target leaves the radiation check location. 2. The speed-through radiation inspection method for moving objects as claimed in claim 1, wherein the moving speed V=(L1-L2)/(t2-t1) of the moving object, wherein L1 and L2 are detection channels respectively The distance between the first position and the second position within the radiation inspection position, the first position and the second position are located on the upstream side of the radiation inspection position, and L1>L2; t1 and t2 are respectively The moment of the second position; the moment when the head of the moving target reaches the second position is taken as the reference moment, and the moment T is later than the first time interval T1=(K+L2)/V of the reference moment. 3. The speed-through radiation inspection method for moving objects as claimed in claim 2, characterized in that, after the moving object leaves the radiation inspection position, and after the second time interval has elapsed since the tail of the moving object leaves the second position, stop emitting rays , the second time interval T2=b*L2/V, b is a constant greater than or equal to 1. 4. The speed-through method for radiation inspection of a moving object according to claim 2, wherein if the moving object decelerates after reaching the second position, the method further comprises: When the head of the mobile target arrives at the second position and does not reach the third position after passing through the third time interval, no rays are emitted when the time T arrives; wherein, The third position is located on the downstream side of the radiation inspection position, the distance from the third position to the radiation inspection position is L3, and L3 is less than or equal to the length K', where K' is the minimum length of the part that needs radiation avoidance among various moving targets; The third time interval is T3=a(L2+L3)/V, where a is a constant greater than or equal to 1. 5. The speed-through radiation inspection method for moving objects as claimed in claim 4, wherein if the moving object decelerates after reaching the second position, when the head of the moving object reaches the second position and passes through the third time interval If the third position is not reached, the ray is not emitted when the time T arrives, and the method further includes: emitting the ray when the head of the moving target reaches the third position. 6 . The speed-through method for radiation inspection of a moving object according to claim 4 , wherein when the tail of the moving object leaves the third position, the emission of rays is stopped. 7 . 7. The speed-through type radiation inspection method for moving objects as claimed in claim 1, wherein the moment when the head of the moving object reaches the fourth position in the detection channel is taken as the reference moment, and the moment T is later than the fourth time of the reference moment interval, the fourth time interval T4=(K+L4)/V; wherein the fourth position is located on the upstream side of the radiation inspection position and is L4 away from the radiation inspection position. 8. A speed-through radiation inspection system for moving targets, characterized in that it comprises: A radiation imaging device is used to emit rays to scan a moving target and generate a radiation image; A moving target information acquisition device, configured to acquire the length K of the part of the moving target that needs radiation avoidance; A moving speed acquiring device, configured to acquire the moving speed V of the moving target in the detection channel; A radiation time determining device, configured to determine the time T when the radiation imaging device emits rays based on the length K and the moving speed V; The radiation control device is used to control the radiation imaging device to emit radiation at the radiation inspection position for radiation inspection when time T arrives, and stop emitting radiation after the moving target leaves the radiation inspection position. 9. The speed-through radiation inspection system for moving objects as claimed in claim 8, wherein the moving speed acquiring device comprises: a first detector and a second detector, for detecting that the moving object arrives or leaves When the signal is sent; wherein, the distance from the first detector to the radiation inspection position is L1, the distance from the second detector to the radiation inspection position is L2, L1>L2, and both the first detector and the second detector are located at the radiation inspection position The upstream side of the moving speed acquisition device obtains the moving speed V=(L1-L2)/(t2-t1) based on the signals sent by the first detector and the second detector, wherein t1 and t2 are respectively the arrival of the moving target at the first moment of the first detector and the second detector. 10. The speed-through radiation inspection system for moving objects as claimed in claim 9, characterized in that, when the radiation moment determining device determines the moment T, the moment when the moving object arrives at the second detector is taken as the reference moment, The determined time T is later than the reference time by a first time interval, and the first time interval is T1=(K+L2)/V. 11. The radiation inspection system for a speed-through moving target according to claim 10, characterized in that the time T' when the radiation imaging device stops emitting rays determined by the radiation time determination device is later than the time T' when the tail of the moving target leaves the first The second time interval at the time of the second detector, the second time interval is T2=b*L2/V, where b is a constant greater than or equal to 1. 12. The speed-through radiation inspection system for moving objects according to claim 9, wherein the radiation control device comprises a third detector, which is located on the downstream side of the radiation inspection position, and the distance to the radiation inspection position is L3 , where L3 is less than or equal to the length K', where K' is the minimum value of the length of the part that needs radiation avoidance among various moving targets; and, If the moving object decelerates after reaching the second detector, so that the head of the moving object does not reach the third detector after reaching the second detector and after a third time interval, the radiation control device controls the radiation imaging device to No rays are emitted when time T arrives, wherein the third time interval is T3=a(L2+L3)/V, where a is a constant greater than or equal to 1. 13. The speed-through type radiation inspection system for moving objects as claimed in claim 12, wherein if the moving object decelerates after it reaches the second detector, the head of the moving object will reach the second detector and pass through the third time. If it does not reach the third detector after an interval, and the radiation imaging device does not emit radiation when time T arrives, the radiation control device controls the radiation imaging device to emit radiation when the head of the moving target reaches the third detector. 14. The speed-through radiation inspection system for moving objects according to claim 12, wherein the radiation control device controls the radiation imaging device to stop emitting rays when the tail of the moving object leaves the third detector. 15. The speed-through type radiation inspection system for moving objects according to claim 8, wherein the moving speed acquisition device comprises a speed measuring radar, a laser speed measuring instrument or a visual speed measuring device. 16. The speed-through radiation inspection system for moving objects according to claim 15, wherein the radiation time determination device comprises at least one detector located upstream of the radiation inspection position, and the first detector in the at least one detector is The distance between the four detectors and the radiation inspection position is L4, the radiation moment determination device takes the moment when the head of the moving target reaches the fourth detector as the reference moment, and the determined moment T is later than the fourth time interval of the reference moment, the fourth Time interval T4=(K+L4)/V. 17. The speed-through radiation inspection system for moving objects as claimed in claim 8, wherein said moving object information acquiring device comprises a moving object identification device and a moving object information database module, wherein the moving object identification device is used for Acquiring the identity data of the moving target; the moving target information database module is used to determine the length K of the part of the moving target that needs radiation avoidance according to the identity data of the moving target. 18. The speed-through type mobile target radiation inspection system according to claim 17, wherein the mobile target identification device includes one or more of the following equipment: license plate number recognition equipment, RFID identification equipment, barcode identification equipment, two-dimensional code identification equipment. 19. The speed-through radiation inspection system for moving objects as claimed in claim 8, wherein said moving object information acquisition device includes an input module for inputting to the system the length K of the part that needs radiation avoidance in the moving object information. 20. The quick-pass radiation inspection system for moving objects according to claim 8, characterized in that the information on the length K of the part of the moving object that needs radiation avoidance is pre-stored in the moving object information acquisition device.