X-ray imaging motion control system based on carbon nanotubes

Abstract

The invention discloses an X-ray imaging motion control system based on a carbon nano tube. The X-ray imaging motion control system comprises a carbon nano tube cold cathode X-ray source, a flat panel detector, a sliding table module, a rotary table, a short sliding table, an optical flat panel, an aluminum alloy frame and an upper computer, a ball screw of each sliding table module is provided with a driving sliding block and a driven sliding block, the driving sliding blocks drive the driven sliding blocks to operate within the full range of the effective stroke of the lead screws under driving of a motor, a flat panel detector and a short sliding table are fixed to the two sliding table modules, a carrying rotary table is fixed to the short sliding table, and a four-axis motion platform is formed. The motion controller controls the output pulse of the motor driver to adjust the running state of the four-axis motor in real time, and the upper computer can achieve the functions of starting, stopping, running distance, running speed, running direction, state display and the like of each axis. The carbon nanotube cold cathode X-ray source can generate continuous and pulse X-rays, and high-efficiency and low-artifact real-time nondestructive inspection of a dynamic object is integrally realized by combining a four-axis motion platform.

Description

Technical Field

[0001] The present invention belongs to the field of X-ray imaging, and in particular relates to an X-ray imaging motion control system based on carbon nanotubes. Background Art

[0002] Traditional hot cathode X-ray sources have inherent defects such as low current density, high operating temperature, and long response time, which make it impossible to achieve miniaturized design and generate stray radiation. The need for a preheating process significantly reduces the efficiency of imaging detection. More importantly, hot cathode X-ray sources can only produce continuous X-rays, which will produce serious motion artifacts when detecting dynamic objects, affecting image resolution and causing defect information to be missed, which makes it impossible to achieve accurate pulsed X-ray imaging. In contrast, carbon nanotube cold cathode X-ray sources work on the principle of field emission, can achieve instantaneous response without preheating, and can produce high-precision controllable pulsed X-rays, thereby effectively solving the problem of motion artifacts in dynamic imaging. Summary of the Invention

[0003] To solve the above problems, the present invention discloses a carbon nanotube-based X-ray imaging motion control system for high-resolution imaging of moving objects, which reduces motion artifacts while achieving efficient detection. A coaxial, bidirectional, and arbitrarily adjustable transmission mechanism is specially designed to maximize the effective travel of the guide rail and improve the system's geometric magnification.

[0004] To achieve the above object, the technical solution of the present invention is as follows: A carbon nanotube-based X-ray imaging motion control system, comprising a carbon nanotube cold cathode X-ray source, a flat-panel detector, a slide module, a turntable, a short slide, an optical flat panel, an aluminum alloy frame, and a host computer control system; The present invention provides a motion control system capable of dynamic object detection. A slide module adjusts the distance between the flat-panel detector and the object under test, as well as the distance between the object under test and the radiation source, thereby varying the system's geometric magnification. A turntable rotates the object under test, enabling three-dimensional defect detection. X-rays generated by the cathode pass through the object under test and form an image on the flat-panel detector, which transmits real-time information about defects within the object.

[0005] The X-ray source used in the present invention is a cold cathode X-ray source based on carbon nanotubes, which includes two types: static vacuum and dynamic vacuum. The static vacuum X-ray source includes a ceramic X-ray tube and a glass X-ray tube. The dynamic vacuum X-ray source can achieve a higher vacuum degree of the ray source through mechanical pumps, molecular pumps, ion pumps and other equipment, and can achieve higher tube voltage and tube current. Both use carbon nanotubes as the cathode material for emitting electrons.

[0006] As a further improvement of the present invention, the ray source is a carbon nanotube microfocus cold cathode X-ray source, which can achieve micron-level high-resolution imaging.

[0007] The present invention can realize coaxial bidirectional motion in the direction of parallel ray emission. The optical plate is fixed on an aluminum alloy frame, and two parallel ball screw slide modules are fixed on the optical plate, wherein the first active slider on the first screw is physically connected to the first screw through the first bearing ball. When the first motor of the slide module rotates, the first active slider is driven to move left and right. The central perforated frame of the first driven slider on the first screw is on the first screw, does not contain a bearing, and does not physically contact the thread of the first screw. The second active slider on the second screw is physically connected to the second screw through the second bearing ball. When the second motor of the slide module rotates, the second active slider is driven to move left and right. The central perforated frame of the second driven slider on the second screw is on the second screw, does not contain a bearing, and does not physically contact the thread of the second screw. The first aluminum alloy connecting frame is fixed to the hole position of the second active slider and the first driven slider by a nut, and the second active slider and the first driven slider will move simultaneously under the action of the second motor. The second aluminum alloy connecting frame is fixed to the holes of the first active slider and the second driven slider by nuts. The first active slider and the second driven slider will move simultaneously under the action of the first motor.

[0008] The present invention secures an X-ray flat-panel detector to a first aluminum alloy connecting frame via nuts, with the center imaging position of the flat-panel detector aligned horizontally with the X-ray exit window of the X-ray source. A short slide is secured horizontally to a second aluminum alloy connecting frame, perpendicular to the direction of X-ray emission. A turntable is secured to the slider of the short slide via screw holes. Driven by the short slide motor, the turntable moves horizontally in the direction of X-ray emission. The turntable rotates in a vertical direction perpendicular to the X-ray emission.

[0009] In practical applications, the present invention requires placing the sample to be tested on a turntable. X-rays emitted from the radiation source pass through the sample to be tested and form an image on a flat-panel detector. The turntable can achieve three-dimensional defect detection of the object to be tested through rotational imaging. The first motor of the slide module rotates to drive the object to be tested to move left and right along the direction of the radiation emission. The second motor of the slide module rotates to drive the flat-panel detector to move left and right along the direction of the radiation emission. This design maximizes the effective travel of the lead screw, ensuring that the flat-panel detector and the object to be tested can be positioned at any position of the lead screw, realizing arbitrary adjustment of the coaxial geometric magnification.

[0010] As a further improvement of the present invention, two metal sensor limiters are installed on both sides of the first active slider. When the flat-panel detector or the object to be measured runs to the two ends of the slide and the distance between the object to be measured and the flat-panel detector is close, the drive motor stops, which can achieve safe operation during the movement process and effectively avoid collision between the detection plate and the object to be measured.

[0011] The host computer control system of the present invention also includes a motion controller board, a motor driver, and host computer software. The motion controller controls the pulse output of the motor driver and enables communication between the host computer and the controller via Gigabit Ethernet. The host computer software can control the system operation status in real time.

[0012] The host computer software of the present invention can realize the start and stop of motor control, arbitrary adjustment of movement speed and position, selection of movement axis, selection of movement and rotation direction, real-time display of current movement coordinates, coordinate zero return, and selection of continuous movement and fixed distance movement modes.

[0013] As a further improvement of the present invention, in order to reduce the motion distance error of the motion unit and achieve high-precision positioning, the motor control methods that can be used include but are not limited to S-type acceleration, PID control, fuzzy PID control, etc.

[0014] As a further improvement of the present invention, since the motion control system is located in the lead cabinet, the host computer can reflect the relative positions of the detection plate, the object and the radiation source through real-time animation, and more intuitively monitor the real-time position of each motion unit.

[0015] As a further improvement to the present invention, to further ensure safe and reliable system operation, the host computer can set the operating distance of the system's soft limit and the alarm prompt of the hard limit. The communication line and the radiation source are electromagnetically shielded by shielded wires, etc., to enhance the system's high-frequency anti-interference ability.

[0016] The X-ray imaging motion control system described in the present invention can achieve both continuous and pulsed X-ray imaging by applying a DC voltage and a pulse voltage to the X-ray source, respectively. The pulse frequency during pulsed imaging is adjustable from 1 to 1000 Hz, with a minimum pulse width of 1 μs. The narrow pulse width of X-rays effectively shortens exposure time and reduces scattered radiation, particularly for imaging of living organisms. This can effectively reduce ionizing radiation damage to both the inspector and the subject. The X-ray imaging system described in the present invention utilizes high-frequency pulsed X-rays to effectively reduce artifacts generated during motion, enabling high-resolution detection during three-dimensional rotation.

[0017] The beneficial effects of the present invention are: 1. The X-ray imaging system of the present invention adopts a cold cathode X-ray source based on carbon nanotubes, which can achieve high-resolution imaging of moving objects.

[0018] 2. The X-ray imaging motion control system described in the present invention is a four-axis motion control system. The left and right movement of the slide module, the short slide drives the longitudinal displacement of the turntable, and the turntable itself drives the rotation of the object to be measured, which can realize three-dimensional dynamic detection of the object to be measured.

[0019] 3. The motion control system of the present invention can realize the coaxial control of the flat-panel detector and the object to be measured, fully utilize the effective stroke, and realize the arbitrary adjustment of the geometric magnification.

[0020] 4. The motion control system of the present invention has the functions of adjustable motion distance, adjustable motion speed, real-time speed display, real-time position display, motion direction selection, motion mode selection, motion axis selection, etc.

[0021] 5. It has strong anti-interference ability, stable operation, strong carrying capacity and wide application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a 45° side and upper view of the X-ray imaging motion control system.

[0023] Figure 2 This is a top view of the X-ray imaging motion control system.

[0024] Figure 3 This is a top view of the system's coaxial bidirectional slide module.

[0025] Figure 4 Front view of the X-ray imaging motion control system.

[0026] Figure 5 Images of the test block at different magnifications.

[0027] Figure 6 Continuous X-ray imaging for the chopper.

[0028] Figure 7 For chopper pulsed X-ray imaging.

[0029] List of Figure Symbols: 100. X-ray source; 110. Turntable; 120. Short slide; 130. Second lead screw of slide module; 140. First lead screw of slide module; 150. Multi-hole optical plate; 160. Aluminum alloy frame; 170. Flat-panel detector; 180. First aluminum alloy connecting frame; 190. Second aluminum alloy connecting frame; 200. First motor of slide module; 210. Second motor of slide module; 220. Short slide motor; 230. First driven slider; 240. First active slider; 250. First active slider bearing; 260. Second driven slider; 270. Second active slider; 280. Second active slider bearing, 290. First slide module, 300. Second slide module. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0031] As shown in the figure, the present invention Example: X-ray motion control system imaging.

[0032] like Figure 1 As shown, the aluminum alloy frame 160 is a hollow rectangular structure. The optical plate 150 with screw holes is fixed horizontally on the aluminum alloy frame 160 by nuts. The four-axis motion platform is fixed on the optical plate 150, which controls the movement of different axes respectively. It includes two parallel slide modules 290 and 300, a short slide 120 and a turntable 110, which can achieve all-round transillumination imaging of the object to be tested. The slide modules 290 and 300 are set at 90 degrees with the short slide 120. The test block is placed on the turntable 110, combined with the Figure 2 As shown, the flat-panel detector 170 is fixed to the first aluminum alloy bracket 180 through screw holes, the short slide 120 is fixed to the second aluminum alloy bracket 190, and the turntable 110 is fixed on the short slide 120. The carbon nanotube cold cathode X-ray source and the flat-panel detector are arranged on both sides of the turntable, and the exit window of the X-ray source 100, the center of the object to be measured and the center position of the flat-panel detector 170 are on the same horizontal line.

[0033] Combined with Figure 3 and 4As shown, the first slide module 290 includes a first motor 200, a first lead screw 140 of the slide module, a first driven slider 230, a first active slider 240, and a first active slider bearing 250. The first driven slider 230 on the first lead screw has a central perforated frame mounted on the first lead screw 140, does not contain a bearing, and does not physically contact the threads of the first lead screw 140. The second slide module 300 includes a second motor 210, a second lead screw 130 of the slide module, a second driven slider 260, a second active slider 270, and a second active slider bearing 280. The second driven slider 260 on the second lead screw has a central perforated frame mounted on the second lead screw 130, does not contain a bearing, and does not physically contact the threads of the second lead screw 130. The first active slider 240 and the second driven slider 260 are fixed together by the second aluminum alloy bracket 190. The first active slider bearing 250 is tightly connected to the first lead screw 140. When the first motor 200 of the slide module rotates, the first active slider bearing 250 drives the second driven slider 260 to operate synchronously. The second active slider 270 and the first driven slider 230 are fixed together by the aluminum alloy bracket 180. The second active slider bearing 280 is tightly connected to the second lead screw 130. When the second motor 210 of the slide module rotates, the second active slider bearing 280 drives the first driven slider 230 to operate synchronously, thus achieving coaxial, bidirectional operation of the X-ray flat panel detector and the object to be measured at any position throughout the entire travel range.

[0034] The X-ray source 100 adopts a DC voltage working mode, and the tube voltage and tube current of the X-ray source 100 are adjusted to 50 kV and 10 μA respectively, and the test block is continuously X-rayed in a sealed lead cabinet.

[0035] The upper computer software controls the rotation of the second motor 210 of the slide module, and the second lead screw 130 drives the flat panel detector 170 to move at a constant speed toward the direction of the test block. The geometric magnification M gradually decreases, and the image data acquisition software obtains images of different frames as shown in FIG. Figure 5 shown.

[0036] The rotation of the first motor of the slide module is controlled by the host computer software. The first lead screw 140 can drive the sample to be tested to move horizontally toward the flat panel detector to reduce the geometric magnification. The host computer can also be used to select the opposite direction to control the sample to be tested to move toward the X-ray source 100 to increase the geometric magnification.

[0037] By controlling the short slide motor 220, the turntable 110's horizontal position relative to the vertical beam exits is varied, enabling complete scanning of the sample under test. By controlling the turntable 110's motor to rotate the object under test clockwise or counterclockwise at a constant speed, three-dimensional transillumination of the sample is achieved. Adjusting the position of the flat-panel detector and the object under test allows for optimal geometric magnification, which minimizes image blur and maximizes resolution.

[0038] The X-ray source 100 adopts a pulse voltage working mode. The carbon nanotube cold cathode X-ray source can apply a pulse voltage to the cathode emitter to generate pulse X-rays with a pulse frequency of 1-1000 Hz and a minimum pulse width of 1 μs.

[0039] The chopper in a rotating state is placed on the turntable 110, and the position of the chopper and the flat panel detector 170 are adjusted, and the tube voltage and tube current of the X-ray source 100 are adjusted to perform X-ray transillumination imaging. Figure 6 For continuous ray imaging, the image details of the chopper shown are severely lost, the generated artifacts have covered the original image information, and the fan blades and fan holes of the chopper cannot be clearly distinguished. Figure 7 The image shows pulsed X-ray imaging, which restores the original details of the object under test. The fan blades and fan holes are clearly visible, and artifacts are significantly reduced.

[0040] Two metal sensor limiters are installed on both sides of the first active slider 240 and the second active slider 270. When the flat-panel detector 170 or the object to be measured runs to the two ends of the effective stroke, or the distance between the object to be measured and the flat-panel detector is close, the drive motor stops, which can achieve safe operation during the movement and effectively avoid collision between the detection plate and the object to be measured.

[0041] The host computer control system includes a motion controller, a motor driver, and host computer software. The motion controller controls the motor driver's pulse output, enabling motor start and stop, arbitrary adjustment of movement speed and position, selection of movement axis, selection of movement and rotation direction, real-time display of current movement coordinates, coordinate return to zero, and selection of continuous movement and fixed-distance movement modes. The motion controller enables communication between the host computer and the controller via Gigabit Ethernet, and the host computer software provides real-time control of the system's operating status.

[0042] The host computer can set the operating distance of the soft limit and the alarm prompt of the hard limit. The communication line and the radiation source are electromagnetically shielded by shielding wires, etc., to enhance the high-frequency anti-interference ability of the system and ensure the safe and reliable operation of the system.

[0043] The slide motor described in the present invention includes but is not limited to a high-torque stepper motor and a servo motor. In order to reduce the motion distance error of the motion unit and achieve high-precision positioning, the motor control methods that can be used include but are not limited to S-type acceleration, PID control, fuzzy PID control, etc.

[0044] The X-ray imaging motion control system can achieve continuous X-ray imaging and pulsed imaging by applying a DC voltage and a pulse voltage to the X-ray source, respectively. The pulse frequency during pulsed imaging can be adjusted from 1 to 1000 Hz, and the minimum pulse width can be as small as 1 μs. The narrow pulse width of X-rays can effectively shorten the exposure time and reduce the generation of scattered rays. Especially for imaging detection of living organisms, it can effectively reduce ionizing radiation damage to the detection personnel and the living organisms to be detected. The X-ray imaging system can use high-frequency pulsed X-rays to effectively reduce the artifacts generated during the object's motion and achieve high-resolution detection during three-dimensional rotation. Reducing imaging artifacts improves detection efficiency and enhances the ability to characterize object defects.

[0045] It should be noted that the above content merely illustrates the technical idea of the present invention and cannot be used to limit the scope of protection of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications all fall within the scope of protection of the claims of the present invention.

Claims

1. A carbon nanotube-based X-ray imaging motion control system, characterized by: It includes a carbon nanotube cold cathode X-ray source, a flat-panel detector, a slide module, a turntable, a short slide, an optical flat panel, an aluminum alloy frame, and a host computer control system; The aluminum alloy frame has a hollow rectangular structure, and an optical flat plate with screw holes is horizontally fixed on the aluminum alloy frame. Two parallel slide modules, a short slide and a turntable are fixed on the optical flat plate, respectively controlling the movement of different axes. The short slide is set at 90° on the slide module, and the turntable is fixed on the short slide. The test block is placed on the turntable, the flat-panel detector is fixed on the first aluminum alloy bracket, and the short slide is fixed on the second aluminum alloy bracket. The carbon nanotube cold cathode X-ray source and the flat-panel detector are arranged on both sides of the turntable, and the exit window of the X-ray source, the center of the object to be tested and the center of the flat-panel detector are on the same horizontal line.

2. The carbon nanotube-based X-ray imaging motion control system according to claim 1, characterized in that: The first slide module includes a first motor, a first lead screw of the slide module, a first driven slider, a first active slider, and a first active slider bearing. The center perforated frame of the first driven slider on the first lead screw is on the first lead screw, does not contain a bearing, and does not make physical contact with the thread of the first lead screw; the second slide module includes a second motor, a second lead screw of the slide module, a second driven slider, a second active slider, and a second active slider bearing. The center perforated frame of the second driven slider on the second lead screw is on the second lead screw, does not contain a bearing, and does not make physical contact with the thread of the second lead screw; the first active slider and the second driven slider are fixed together by a second aluminum alloy bracket, and the first active slider bearing is tightly connected to the first lead screw. The second active slider and the first driven slider are fixed together by an aluminum alloy bracket, and the second active slider bearing is tightly connected to the second lead screw.

3. The carbon nanotube-based X-ray imaging motion control system according to claim 1, characterized in that: The carbon nanotube cold cathode X-ray source adopts a pulse voltage working mode. The carbon nanotube cold cathode X-ray source applies a pulse voltage to the cathode emitter to generate pulse X-rays with a pulse frequency of 1-1000Hz and a minimum pulse width of 1μs.

4. The carbon nanotube-based X-ray imaging motion control system according to claim 2, characterized in that: Two metal sensor limiters are installed on both sides of the first active slider and the second active slider.

5. The carbon nanotube-based X-ray imaging motion control system according to claim 1, characterized in that: The host computer control system includes a motion controller, a motor driver, and host computer software. The motion controller controls the pulse output of the motor driver and realizes communication between the host computer and the controller through Gigabit Ethernet. The host computer software controls the system operation status in real time.

6. The carbon nanotube-based X-ray imaging motion control system according to claim 2, characterized in that: Motors include but are not limited to high-torque stepper motors and servo motors.

7. The carbon nanotube-based X-ray imaging motion control system according to claim 1, characterized in that: Its working principle is: When the first motor of the slide module rotates, it drives the first active slider and the second driven slider to move left and right at the same time; when the second motor of the slide module rotates, it drives the second active slider and the first driven slider to move left and right at the same time; by moving the slide module, the distance between the flat-panel detector and the object to be measured, and the distance between the object to be measured and the radiation source can be adjusted, maximizing the effective stroke of the lead screw, ensuring that the flat-panel detector and the object to be measured can be positioned at any position of the lead screw, thereby changing the geometric magnification of the system. The slide module moves left and right, the short slide drives the longitudinal displacement of the turntable, and the turntable itself drives the rotation of the object to be tested, realizing three-dimensional detection of object defects; the X-rays generated by the carbon nanotube cold cathode X-ray source pass through the object to be tested and are uploaded to the host computer control system through the flat-panel detector to realize micron-level high-resolution imaging.

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