CN108758189B - Scanning platform for imaging radiometer - Google Patents

Abstract

The invention discloses a scanning platform for an imaging radiometer, comprising a T-shaped bracket; a first linear displacement mechanism, a second linear displacement mechanism, an oil pump, which are connected to the linear displacement mechanism and an oil tank; and a controller connected to the the linear displacement mechanism and the oil pump; and a host computer, which communicates with the controller through a serial port, the host computer is provided with a display device; the linear displacement mechanism comprises: a driving mechanism, a first guide rail, a first slider, It is slidably arranged in the first guide rail, the second guide rail is arranged on the upper end of the first guide rail, the second slider is slidably arranged in the second guide rail, and the third slider is connected to the The upper end of the second sliding block is a distance measuring module, wherein the oil pump is spatially communicated with the inner end of the second guide rail through a solenoid valve, and a flow meter is arranged on the solenoid valve. The invention solves the technical problem of inaccurate moving distance of the sliding table on the scanning platform.

Description

A scanning platform for imaging radiometers

technical field

The invention relates to the technical field of automatic control, in particular to a scanning platform for an imaging radiometer.

Background technique

The millimeter-wave synthetic aperture imaging radiometer, hereinafter referred to as the radiometer, uses an antenna array composed of small-diameter antennas to measure the millimeter-wave radiation signal of the target scene with high sensitivity, and measures the visibility function of the scene through the complex correlation operation between the array elements. Invert the brightness temperature distribution image of the target scene. Compared with traditional real aperture imaging technology, synthetic aperture imaging technology has the characteristics of good real-time performance and high spatial resolution. Imaging, has been widely used in military, navigation, medical and traffic security and other fields. The basic composition of the synthetic aperture imaging system is a binary interferometer, which can achieve coherent imaging of the target scene with the help of a two-dimensional antenna scanning platform.

The sliding table on the existing two-dimensional antenna scanning platform is generally directly driven by a motor, and the motor has a minimum step angle and inertial rotation, resulting in a minimum moving distance of the sliding table each time it travels, so that the position of the sliding table is consistent with the target position. Deviation occurs, resulting in deviation of the scanning position of the antenna installed on the sliding table, and finally the image is distorted. On the other hand, because the lead screw driving the slide table is relatively long and slightly bent, the lead screw will periodically shake slightly when it rotates, which will cause the slide table to also shake, causing the antenna to vibrate, and finally cause the image to vibrate and affect the imaging. quality.

SUMMARY OF THE INVENTION

An object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages which will be explained later.

The purpose of the present invention is to provide a two-dimensional antenna scanning platform for a radiometer, which enables the array element antenna of the synthetic aperture imaging radiometer to perform plane scanning according to a certain working mode. The antenna is indirectly installed on the ball screw guide rail slide table through the hydraulic system, and the stepper motor is controlled by the single chip microcomputer to rotate through the stepper motor driver, thereby driving the slide table to move in the horizontal or vertical direction to realize plane scanning. The invention solves the technical problem of inaccurate moving distance of the sliding table on the scanning platform.

To achieve these objects and other advantages in accordance with the present invention, a scanning platform for an imaging radiometer is provided, comprising:

T-shaped bracket;

a first linear displacement mechanism, which is arranged on the transverse support of the T-shaped support;

a second linear displacement mechanism, which is arranged on the longitudinal support of the T-shaped support;

an oil pump, communicated with the linear displacement mechanism and an oil tank;

a controller connecting the linear displacement mechanism and the oil pump; and

a host computer, which communicates with the controller through a serial port, and a display device is provided on the host computer;

The linear displacement mechanism includes:

a drive mechanism connected to the controller;

The first guide rail is set as a closed structure. A screw rod connected with the drive shaft of the driving mechanism is arranged in the first guide rail along the length direction. A brake controlled by a device, the brake is provided with a tightenable brake hoop, the inner side wall of the brake hoop is provided with a brake pad, and the brake is arranged on the first guide rail through a shock absorbing mechanism On the upper side, the tail end of the screw rod protrudes from the outer side wall of the tail end of the first guide rail for a certain distance, and extends into the brake hoop;

a first sliding block, which is slidably arranged in the first guide rail, and the first sliding block is sleeved on the screw rod;

a second guide rail, which is arranged on the upper end of the first guide rail, the inner space of the second guide rail is communicated with the inner space of the first guide rail at the end, and the upper end of the second guide rail is covered with a cover plate with a slot;

A second sliding block, which is slidably arranged in the second guide rail, between the first sliding block and the end of the first guide rail, and between the second sliding block and the end of the second guide rail Filled with hydraulic oil, a guide rod extends upward from the upper end of the second sliding block from the slot;

a third sliding block connected to the upper end of the guide rod, the third sliding block is slidably arranged on the cover plate, and a roll plate for sealing the slot is connected to the guide rod; and

A ranging module, which is arranged at the rear end of the second guide rail, the ranging port of the ranging module is aligned with the rear end of the third slider, and the output end of the ranging module is connected to the controller connect;

Wherein, the oil pump is connected to the inlet of a buffer through a solenoid valve, the buffer is filled with hydraulic oil, the longitudinal cross-sectional area of the buffer is not less than the longitudinal cross-sectional area of the second guide rail, and the buffer is The outlet of the second guide rail is in communication with the inner end space of the second guide rail, and a flow meter is arranged on the solenoid valve.

Preferably, the linear displacement mechanism is arranged on the T-shaped bracket through a mounting seat, the driving mechanism is a stepping motor, and the driving mechanism is drivingly connected to the screw rod through a connecting seat.

Preferably, the longitudinal section of the first sliding block is consistent with the longitudinal section of the inner space of the first guide rail, the two inner side walls of the first guide rail are provided with first guide grooves, and the side walls of the first sliding block are provided with first guide grooves. A first guide block is correspondingly arranged on the upper part, the first guide block is slidably arranged in the first guide groove, and the outer periphery of the end of the first slider is provided with a first sealing ring.

Preferably, a threaded hole runs through the center of the first slider along the length direction, the first slider is sleeved on the screw rod through the screw hole, and a threaded hole is provided between the screw hole and the screw rod. Threaded glands.

Preferably, the upper end of the first guide rail is sealed with a first cover plate, and a plurality of through holes are opened at the end of the first cover plate; the second guide rail is arranged on the upper end of the first cover plate, and the second The inner space of the guide rail communicates with the inner space of the first guide rail through the through hole.

Preferably, the longitudinal section of the second sliding block is the same as the longitudinal section of the inner space of the second guide rail, the two inner side walls of the second guide rail are provided with second guide grooves, and the side walls of the second sliding block are provided with second guide grooves. A second guide block is correspondingly arranged on the upper part, the second guide block is slidably arranged in the second guide groove, and a second sealing ring is arranged on the outer periphery of the end of the second sliding block.

Preferably, the upper end of the second guide rail is sealed with a second cover plate, the second cover plate is provided with a guide groove, the third slider is slidably arranged on the guide groove through the guide rod, and the The slot runs through the center of the second cover plate along the length direction, the two inner side walls of the slot are provided with a third guide groove, the two side walls of the guide rod are correspondingly provided with a third guide block, and the A sealant pad is arranged in the third guide groove, and the third guide block is slidably arranged in the sealant pad.

Preferably, an accommodating box is arranged on the outside of the second guide rail, an elastic scrolling device is arranged in the accommodating box, the rolling plate is wound around the outer periphery of the elastic scrolling device, and the accommodating box is arranged on There is a straightening opening through which the free end of the coiled plate is connected to the side wall of the end of the guide rod, the width of the coiled plate is greater than the width of the slot, and both sides of the free end of the coiled plate are connected. Slide set in the sealant pad.

Preferably, both ends of the first slide block are provided with a first touch switch, both ends of the second slide block are provided with a second touch switch, and both ends of the third slide block are provided with a third touch switch , and an origin switch is protruded from the end of the second guide rail, and an end switch is protruded from the tail end of the second guide rail, and each of the switches is connected to the controller.

Preferably, the oil tank is arranged on the T-shaped bracket, the inlet of the oil pump is communicated with the oil outlet of the oil tank, the outlet of the oil pump is communicated with the inlet of the buffer through the first solenoid valve, the The first solenoid valve is provided with a first flow meter, the inner end of the second guide rail is provided with a calibration oil return port, and the calibration oil return port is communicated with the oil tank oil return port through a second solenoid valve, The second solenoid valve is provided with a second flow meter, and each of the solenoid valve and the flow meter is respectively connected with the controller.

Compared with the prior art, the beneficial effects contained in the present invention are:

1. The present invention utilizes the serial communication between the host computer and the single-chip computer to realize the control and display of the scanning system on the host computer, including the manipulation of the scanning system, the modification of the operating parameters of the scanning system, and the real-time display of the current sliding table position, which optimizes the The control process of the scanning platform;

2. The present invention has the characteristics of high precision, simple and convenient operation, good stability and high safety, and provides a necessary platform basis for high-precision imaging of the millimeter-wave synthetic aperture radiometer;

3. The moving process of the sliding table of the present invention is more accurate, and the shaking of the sliding table is eliminated, and the imaging quality is improved.

Other advantages, objects, and features of the present invention will appear in part from the description that follows, and in part will be appreciated by those skilled in the art from the study and practice of the invention.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the structural representation of the first linear displacement mechanism of the present invention;

FIG. 3 is a schematic structural diagram of a first slider;

4 is a schematic diagram of the internal structure of the first guide rail;

5 is a schematic diagram of the internal structure of the second guide rail;

6 is a schematic view of the top structure of the second guide rail;

7 is a schematic diagram of the assembly structure of the third slider;

Figure 8 is a side view of the first linear displacement mechanism;

FIG. 9 is a schematic diagram of the installation structure of the coil plate.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can refer to the description text and implement accordingly.

As shown in Figures 1-9, the present invention provides a scanning platform for an imaging radiometer, including a bracket, a linear displacement mechanism, an oil pump and a control system.

The distribution of two-dimensional arrays currently used in imaging systems mainly includes: "T"-shaped distribution, "cross"-shaped distribution, "U"-shaped distribution, "Y"-shaped distribution, circular distribution and other similar distributions. After simulation and analysis of the baseline (that is, the visibility sampling points) distribution and the point source imaging results (that is, the point spread function PSF) of the above several two-dimensional antenna arrays, it can be found that the "U"-type and "T"-type antenna arrays have different characteristics. The distribution of array elements is similar, their corresponding baseline distributions are uniform rectangular distributions, and their array structures are relatively simple, so they are the more commonly used synthetic aperture antenna arrays at present; but their baseline redundancy is relatively high, although it can be achieved by The same baselines are averaged and summed to enhance the image restoration effect, but their array element antenna utilization is not high, so the spatial resolution of the system is relatively low. Compared with the "T"-type array, the "U"-type array increases the spacing of the antenna elements in the vertical direction, and the azimuth resolution in the vertical direction is improved, but it also reduces the alias-free field of view in the vertical direction. Makes it appear aliasing phenomenon in PSF. The "Y" and circular arrays take into account the reduction of antenna redundancy and the improvement of system spatial resolution at the same time. Unlike the previously described "T" and "U" antenna arrays, the "Y" and circular types greatly reduce their baseline redundancy and increase their maximum baseline length. However, the disadvantage is that the "Y" type lacks many long baselines, which makes its effect on the resolution improvement not obvious; while the circular array can improve the spatial resolution better due to the uniform distribution of the long baselines. However, the improvement of spatial resolution brings about the lack of baseline. By observing its PSF, it is not difficult to see that there is more or less accompanying noise in its point source response, and accompanying noise will greatly affect the recovery of continuous targets; It may occur that the accompanying noise generated by some targets with strong point source response exceeds the original point source response of the weak target, so that the target with weak point source response cannot be recovered. This situation will be particularly serious.

In order to make the imaging effect better, the present invention adopts the antenna array of "T"-shaped structure with good PSF and simple structure, and provides a T-shaped bracket for this purpose, and the "T"-shaped structure can be realized by moving the antenna on the T-shaped bracket. antenna array.

The transverse support of the T-shaped bracket is provided with a first linear displacement mechanism 300, the first linear displacement mechanism 300 is horizontally installed on the transverse support through the mounting seat 100, and the longitudinal support of the T-shaped support is provided with a The second linear displacement mechanism 400, the second linear displacement mechanism 400 is vertically installed on the longitudinal support through the mounting seat 200, the first linear displacement mechanism 300 is provided with a third slider 700 for carrying the antenna, the second linear displacement mechanism 400 A third slider 800 for carrying the antenna is provided thereon.

The structures of the first linear displacement mechanism 300 and the second linear displacement mechanism 400 are the same, and the first linear displacement mechanism 300 is described in this embodiment.

The first linear displacement mechanism 300 includes:

The driving mechanism 310 is connected to the controller of the scanning platform. In this embodiment, the driving mechanism 310 adopts a stepping motor, so as to accurately adjust the scanning step distance each time;

The first guide rail 320 is set as a closed structure, the upper end of the first guide rail 320 is sealed with the first cover plate 500 , an accommodating space is provided inside the first guide rail 320 , and a The lead screw 340 connected with the drive shaft of the drive mechanism 310; specifically, the drive mechanism 310 is drivingly connected with the lead screw 340 through a connecting seat 311, and the lead screw 340 is located in the center of the inner space of the first guide rail 320;

The first sliding block 330 is slidably arranged in the first guide rail 320, and the first sliding block 330 is sleeved on the screw rod 340. When the driving mechanism 310 drives the screw rod 340 to rotate, it can be controlled The first sliding block 330 moves back and forth in the first guide rail 320;

The second guide rail 540 is arranged on the upper end of the first guide rail 320 . Specifically, the second guide rail 540 is overlapped and arranged on the upper end of the first cover plate 500 , and the direction of the second guide rail 540 is the same as that of the first guide rail 320 . Consistently, an accommodating space is also provided inside the second guide rail 540 , and the inner space of the second guide rail 540 communicates with the inner space of the first guide rail 320 at the end. Specifically, the end of the first cover plate 500 A number of through holes 510 are formed in the longitudinal direction, and the inner space of the second guide rail is communicated with the inner space of the first guide rail through the through holes 510; the upper end of the second guide rail 540 is sealed with a second cover plate 600 with a slot 610. cover;

The second sliding block 520 is slidably arranged in the second guide rail 540 , between the first sliding block 330 and the end of the first guide rail 320 , and between the second sliding block 520 and the second sliding block 520 The ends of the guide rails 540 are filled with hydraulic oil, and since the inner space of the second guide rail and the inner space of the first guide rail communicate with each other through the through holes 510 at the ends, when the first slider is driven on the first guide rail When moving back and forth in the middle, the capacity of the hydraulic oil between the second slider 520 and the end of the second guide rail 540 will be changed, thereby changing the position of the second slider in the second guide rail; the second slider A guide rod 620 extends upward from the slot 610 from the upper end of the block 520;

The third sliding block 700 is connected to the upper end of the guide rod 620 , and the third sliding block 700 is slidably arranged on the second cover plate 600 , so that the third sliding block 700 moves synchronously with the second sliding block 520 , the antenna is arranged on the third slider 700, and the scanning of the target object by the antenna can be completed by gradually changing the position of the third slider; the guide rod 620 is connected with a rolling plate 531 for sealing the slot 610, for closing the slot 610 between the guide rod 620 and the end of the second guide rail, so that a closed cavity is formed between the second sliding block 520 and the end of the second guide rail; and

The ranging module 350 is disposed at the rear end of the second guide rail 540 . In the present invention, the ranging module 350 adopts an infrared distance sensor, and the ranging port of the ranging module 350 is aligned with the third slider 700 The tail end of the 350 is used to measure the position and moving distance of the third slider, and transmit the collected information of the ranging module 350 to the controller;

The connection seat 311 is also provided with an oil pump, which is connected to the inlet of a buffer, the buffer is filled with hydraulic oil, and the outlet of the buffer is in space communication with the inner end of the second guide rail 540 . A flow meter is set on the solenoid valve, and the oil pump is used to fine-tune the hydraulic oil volume inside the second guide rail 540, that is, to fine-tune the position of the third slider. Therefore, the oil pump acts as a fine-tuning switch, through the volume of hydraulic oil. To fine-tune the position, the adjustment step is smaller, and the adjustment distance is more precise and controllable.

The buffer is used to buffer the oil pumping process. The longitudinal cross-sectional area of the buffer is not less than the longitudinal cross-sectional area of the second guide rail, so as to reduce the amount of oil fed in when the oil pump starts and stops. The instantaneous impact generated by the oil volume, that is, the impact on the second slider, causes the second slider, the third slider and the scanning system installed on the third slider to shake, which affects the image quality. At the moment when the oil pump starts and stops , the amount of oil pumped by the oil pump enters the second guide rail after being buffered by the buffer, so as to slowly change the oil amount in the second guide rail, that is, slowly change the position of the second slider to adjust the position of the second slider. Fine-tuning to avoid the jitter of the second slider when the oil pump starts and stops, thereby improving the imaging quality of the scanning system.

In the above technical solution, the longitudinal section of the first sliding block 330 is consistent with the longitudinal section of the inner space of the first guide rail 320, so that the first sliding block 330 is just movably arranged to move in the inner space of the first guide rail 320, In addition, first guide grooves 321 are provided on the two inner side walls of the first guide rail 320, and first guide blocks 335 are correspondingly provided on the side walls of the first slider 330, and the first guide blocks 335 are slidably arranged on the The first guide groove 321 provides guidance for the sliding of the first sliding block 330, and at the same time ensures that the first sliding block 330 strictly moves linearly along the direction of the first guide rail, reduces the longitudinal offset, and finally reduces the first sliding block 330. At the same time, a first sealing ring 331 is provided on the outer periphery of the end of the first sliding block 330, and the first sliding block 330 slides with the surrounding side walls of the inner space of the first guide rail 320 through the first sealing ring 331 contact, to ensure the tightness of the contact position between the first sliding block 330 and the inner space of the first guide rail 320, and avoid the leakage of hydraulic oil between the first sliding block 330 and the end of the inner space of the first guide rail 320 to the first sliding block 330 and the rear end of the inner space of the first guide rail 320 .

A threaded hole 334 runs through the center of the first sliding block 330 along the length direction, the first sliding block 330 is sleeved on the screw rod 340 through the screw hole 334, and the driving mechanism controls the first sliding block 330 by rotating the screw rod. A slider moves back and forth in the first guide rail 320 to change the volume of hydraulic oil between the first slider 330 and the end of the inner space of the first guide rail 320, thereby changing the space between the second slider and the end of the inner space of the second guide rail The volume of hydraulic oil drives the second slider to move, and finally changes the position of the antenna on the third slider, driving the antenna to scan the target object. The antenna on the platform of the invention is indirectly installed on the ball screw guide rail sliding table through the hydraulic system, the position of the antenna is adjusted by the hydraulic system, the hydraulic system changes the scanning step by changing the volume of the hydraulic oil, the minimum step is smaller, and The adjustment is more precise, eliminates the deviation between the antenna and the target position, absorbs the jitter when the drive mechanism starts and stops, so that the antenna movement process is more precise and controllable, and through the hydraulic system, the longitudinal jitter of the sliding table is eliminated, and finally The scanning imaging quality of the antenna is improved.

A threaded sealing sleeve 333 is arranged between the threaded hole 334 and the screw rod 340, which plays a sealing role between the screw hole 334 and the screw rod 340, and prevents hydraulic oil from protruding into the screw hole.

Similarly, the longitudinal section of the second sliding block 520 is consistent with the longitudinal section of the inner space of the second guide rail 540, so that the second sliding block is just movably arranged to move in the inner space of the second guide rail, and the first sliding block is moved in the inner space of the second guide rail 540. The two inner side walls of the two guide rails 540 are provided with second guide grooves, the side walls of the second slider 520 are correspondingly provided with second guide blocks, and the second guide blocks are slidably arranged in the second guide grooves , provide guidance for the sliding of the second slider, and at the same time ensure that the second slider moves in a straight line strictly along the direction of the second guide rail, reduce the longitudinal offset, and finally reduce the longitudinal jitter of the second slider. A second sealing ring 522 is provided on the outer periphery of the end of the second sliding block 520 , and the second sliding block 520 is in sliding contact with the surrounding side walls of the inner space of the second guide rail 540 through the second sealing ring 522 to ensure that the second sliding block 520 is in contact with the second sliding block 520 . The tightness at the contact position of the inner space of the two guide rails 540 prevents hydraulic oil from leaking between the second slider 520 and the end of the inner space of the second guide rail 540 to the end of the inner space of the second slider 520 and the second guide rail 540 between.

The second sliding block is driven by the hydraulic system. Specifically, the driving mechanism drives the screw to rotate according to the set procedure, so as to change the volume of hydraulic oil between the first sliding block 330 and the end of the inner space of the first guide rail 320, thereby changing the first block The volume of hydraulic oil between the second sliding block and the inner space end of the second guide rail drives the second sliding block to move, and finally changes the position of the antenna on the third sliding block, driving the antenna to scan the target object.

In the above technical solution, a brake controlled by the controller is provided on the outer side wall of the rear end of the first guide rail 320, and a brake hoop that can be tightened is provided on the brake. It is composed of contracted semi-circular hoop, the two semi-circular hoop can be expanded outward or retracted inward, brake pads are provided on the inner side wall of the braking hoop, and the tail end of the screw rod protrudes out of the first A certain distance from the outer side wall of the tail end of a guide rail extends into the braking hoop. The driving mechanism 310 drives the screw rod 340 to rotate and drives the first slider 330 to move, thereby changing the position of the antenna on the third slider. When the slider moves to the set target position, in order to reduce the influence of the inertia of the drive mechanism on the displacement of the third slider, the brake hoop is controlled to shrink, and the brake pad and the screw are locked to reduce the third slider. The offset from the target position. When the drive mechanism is restarted to control the movement of the third slider, the brake hoop is controlled to expand outward, the brake hoop is loosened from the screw rod, and the screw rod rotates normally until the first slider moves.

The brake is arranged on the first guide rail through a damping mechanism, so as to reduce the impact of the shock during the braking process on the first guide rail and even the third slider, reduce jitter, and improve the scanning quality of the scanning device .

In the above technical solution, the upper end of the second guide rail 540 is sealed with a second cover plate 600. The second cover plate 600 is provided with a guide groove 630, and the direction of the guide groove 630 is the same as the length direction of the first guide rail and the second guide rail. Consistently, the third slider 700 is slidably arranged on the guide groove 630 through the guide rod 620 to provide guidance for the sliding of the third slider, while ensuring that the third slider strictly follows the length direction of the first guide rail Linear movement reduces the longitudinal offset, and finally reduces the longitudinal jitter of the third slider. The slot 610 runs through the center of the second cover 600 along the length direction, and is provided on both inner side walls of the slot 610 There is a third guide groove, the two side walls of the guide rod 620 are correspondingly provided with a third guide block, and the third guide groove is provided with a sealing gasket, and the third guide block is slidably arranged on the In the sealing gasket, the tightness of the contact position between the guide rod 620 and the slot 610 is ensured, and the hydraulic oil between the second slider and the end of the inner space of the second guide rail is prevented from leaking out of the slot.

At the same time, an accommodating box 530 is arranged on the outside of the second guide rail 540, and an elastic scrolling device is arranged in the accommodating box 530. The coil plate 531 is wound around the outer circumference of the elastic scrolling device 533. Under the elastic force of the moving device 533, the rolling plate 531 is kept in a retracted state, a straightening opening 532 is provided on the accommodating box 530, and the free end of the rolling plate 531 passes through the straightening opening 532 and the guide rod 620. The side walls of the ends are connected, and the guide rod 620 straightens the roll plate 531 through the straightening opening 532 and pulls it out. Specifically, the width of the roll plate 531 is greater than the width of the slot 610, and the free end of the roll plate 531 The two sides are slidably arranged in the sealing pad, and the sealing pad is sealed with the slot. When the second slider is forced to slide, the driving guide rod moves in the slot, the guide rod is sealed with the slot, and the guide rod is The slot between the ends of the second guide rail is sealed by the pulled out coil plate in real time, so as to avoid leakage of the hydraulic oil between the second slider and the end of the inner space of the second guide rail from the slot.

Both ends of the first slider 330 are provided with a first touch switch 332, both ends of the second slider 520 are provided with a second touch switch 521, and both ends of the third slider 700 are provided with a third touch switch. Touch the switch 710, and an origin switch 640 is protruded from the end of the second guide rail 540, and an end switch 360 is protruded from the tail end of the second guide rail 540. Each of the switches is connected to the controller. The end of 630 is provided with a first baffle 650, the origin switch 640 is set on the first baffle 650, the tail end of the guide groove 630 is provided with a second baffle 370, the end switch 360 is set on the second baffle 370, touch The switch generates a contact signal, which is sent to the controller, and the controller controls the corresponding slider to stop moving, that is, the touch switch is used to limit the movement of the slider to avoid direct collision between the slider and the end or tail of the guide rail. The origin switch is 640 And the end switch 360 is used to calibrate the origin and end of the moving path of the third slider, improve the moving accuracy of the antenna, and eliminate the accumulated error of the moving stroke.

In this embodiment, each linear displacement mechanism is further provided with an oil tank. Specifically, the oil tank is arranged on the T-shaped bracket, the two linear displacement mechanisms share a mailbox, and each linear displacement mechanism is equipped with an oil pump. The inlet of the oil pump communicates with the oil outlet of the oil tank, the outlet of the oil pump communicates with the inlet of the buffer through the first solenoid valve, and the outlet of the buffer communicates with the inner end of the second guide rail 540 The first solenoid valve is provided with a first flow meter, the inner end of the second guide rail 540 is provided with a calibration oil return port, and the calibration oil return port is connected to the The oil return port of the oil tank is communicated, the second solenoid valve is provided with a second flow meter, and each of the solenoid valves and the flow meter is respectively connected with the controller.

A buffer is also arranged between the calibration oil return port and the second solenoid valve. After the hydraulic oil in the first guide rail is buffered by the buffer, it returns to the oil tank through the second solenoid valve, and the buffer reduces the second At the moment when the solenoid valve is opened, the flow of hydraulic oil has an instant impact on the oil in the first guide rail, which further reduces the jitter of the second slider and the scanning device installed on the third slider, thus improving the scanning of the scanning device. Under the premise of accuracy, the shaking of the scanning device is reduced, the scanning quality of the entire scanning device installed on the third sliding block is improved, and the imaging quality of the scanning system is finally improved.

The controller controls the movement stroke of the third slider to realize the scanning and imaging of the target object by the antenna, and at the same time, feeds back the moving position and moving distance of the third slider through the ranging module. Accumulated operation will inevitably lead to position deviation. Once the position of the third slider deviates from the target set position, for example, the position of the third slider has not reached the target position, at this time, the controller calculates the third slider Since the longitudinal cross-sectional area of the inner space of the second guide rail is constant, the deviation volume of the hydraulic oil in the inner space of the second guide rail can be calculated. After the oil is buffered by the buffer, it is replenished to the inner space of the second guide rail. The first flow meter measures the volume of the hydraulic oil that flows in. When the hydraulic oil inflow reaches the deviation volume, the oil pump and the first solenoid valve are controlled to close at the same time, and the inside of the second guide rail is controlled. After the hydraulic oil in the space obtains the hydraulic oil of the deviation volume, the second slider can be driven to link the third slider to the specified target position, thereby eliminating the displacement deviation in time and improving the scanning accuracy of the antenna.

For example, after the position of the third slider exceeds the target position by a certain distance, at this time, the controller calculates the deviation distance of the third slider, because the longitudinal cross-sectional area of the inner space of the second guide rail is constant, the inner space of the second guide rail can be calculated. The deviation volume of the hydraulic oil, open the second solenoid valve, return the hydraulic oil in the inner space of the second guide rail to the oil tank, and the second flow meter measures the volume of the outflowing hydraulic oil until the outflowing hydraulic oil reaches the deviation volume, and controls the first The second solenoid valve is closed, and after the hydraulic oil of the deviation volume of the hydraulic oil in the inner space of the second guide rail flows out, the second slider can be driven to link the third slider to the specified target position, thereby eliminating the displacement deviation in time and improving the scanning accuracy of the antenna. .

In this embodiment, the host computer communicates with the controller through a serial port, the host computer is provided with a display device, the controller adopts 52 single-chip microcomputer, and the system uses the host computer control system, 42HBS48BL4-TF7 stepping motor and its driver, The ball linear guide slide table and 52 single chip microcomputer are used to design and manufacture a millimeter synthetic aperture radiometer antenna scanning platform. Using the serial communication between the host computer and the single-chip microcomputer, the control and display of the scanning system on the host computer are realized, including the control of the scanning system, the modification of the operating parameters of the scanning system, and the real-time display of the current slide position. The operation is convenient, intuitive and flexible. .

The parameter setting process of the scanning platform is as follows. When the serial port is successfully opened, the parameters can be changed. The default parameters are: scan 50 points in the horizontal direction, that is, n1=50, and the scanning step length is 20mm, that is, l1=20mm; Scan 25 points, that is, n2=25, the scanning step is 20mm, that is, l2=20mm; the dwell time of each step is 1s, that is, t=1s.

It should be noted that the effective stroke of the horizontal slide table is 1000mm, and the effective stroke of the vertical slide table is 500mm, so the parameters of the scanning platform must satisfy n1×l1≤1000mm, n2×l2≤500mm, otherwise the slide table will move more than 500mm. In the end, serious damage is done to the system. Of course, this system has successfully solved this problem. When the serial port is successfully opened, the host computer will send commands through the serial port to query the current scanning platform parameters of the 52 MCU, and display them on the interface. At the same time, the parameters will also display their limit prompts based on the current parameters. .

When the system is running, in order to facilitate the observation of the position of the slide table of the scanning system, the function of displaying the real-time position of the slide table is designed, including text display and image display. The schematic diagram of the platform, and the position of the slide table is marked in the figure. Through the method of image display, the real-time position of the sliding table can be displayed on the host computer clearly and intuitively. Of course, it will be inaccurate when recognizing the image, so the position information displayed by the text is also provided. In this way, the text and the image are displayed together, and the position of the slide table at this time can be clearly confirmed.

In order to verify the effect of the platform of the present invention, a 5mW laser is used as a test tool, and the 5mW laser is set on the third slider to test the stability of the system during operation and the jitter of the slider during operation. Record the set running distance and the actual running distance when the slide table is running to test the accuracy of the system. Finally, the test system outputs the waveform, and this pulse will be sent to the subsequent radiometer measurement system as its prompt signal to analyze its accuracy.

The test proves that the jitter of the third slider is very small when the system is running, and the jitter in the vertical direction is much smaller than that in the horizontal direction. . At the same time, there is almost no error between the set position and the actual position of the system operation, so it can be seen that the system operation accuracy is very high. After every 6 test pulse signals, a line feed pulse signal is generated, and the pulses are sent out just after the slide table stops at each running step, which reserves enough time for the subsequent test system to collect data, including the slide table at the initial value point. There is also a test pulse when the system is just running but not yet running, so the design is fully compliant with the system requirements.

From the above, the present invention utilizes the serial communication between the host computer and the single-chip microcomputer to realize the control and display of the scanning system on the host computer, including the manipulation of the scanning system, the modification of the operating parameters of the scanning system, and the real-time display of the current sliding table position. , the control process of the scanning platform is optimized; at the same time, the invention has the characteristics of high precision, simple and convenient operation, good stability and high safety, and provides a necessary platform foundation for the high-precision imaging of the millimeter-wave synthetic aperture radiometer; Finally, the moving process of the sliding table of the present invention is more accurate, and the shaking of the sliding table is eliminated, and the imaging quality is improved.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the application listed in the description and the embodiment, and it can be applied to various fields suitable for the present invention. For those skilled in the art, it can be easily Therefore, the invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the appended claims and the scope of equivalents.

Claims (10)

1. a scanning platform for imaging radiometer, is characterized in that, comprises: T-shaped bracket; a first linear displacement mechanism, which is arranged on the transverse support of the T-shaped support; a second linear displacement mechanism, which is arranged on the longitudinal support of the T-shaped support; an oil pump, communicating with each of the linear displacement mechanisms and an oil tank; a controller connecting each of the linear displacement mechanisms and the oil pump; and a host computer, which communicates with the controller through a serial port, and a display device is provided on the host computer; Each of the linear displacement mechanisms includes: a drive mechanism connected to the controller; The first guide rail is set as a closed structure. A screw rod connected with the drive shaft of the driving mechanism is arranged in the first guide rail along the length direction. A brake controlled by a device, the brake is provided with a tightenable brake hoop, the inner side wall of the brake hoop is provided with a brake pad, and the brake is arranged on the first guide rail through a shock absorbing mechanism On the upper side, the tail end of the screw rod protrudes from the outer side wall of the tail end of the first guide rail for a certain distance, and extends into the brake hoop; a first sliding block, which is slidably arranged in the first guide rail, and the first sliding block is sleeved on the screw rod; a second guide rail, which is arranged on the upper end of the first guide rail, the inner space of the second guide rail is communicated with the inner space of the first guide rail at the end, and the upper end of the second guide rail is covered with a cover plate with a slot; A second sliding block, which is slidably arranged in the second guide rail, between the first sliding block and the end of the first guide rail, and between the second sliding block and the end of the second guide rail Filled with hydraulic oil, a guide rod extends upward from the upper end of the second sliding block from the slot; a third sliding block connected to the upper end of the guide rod, the third sliding block is slidably arranged on the cover plate, and a roll plate for sealing the slot is connected to the guide rod; and A ranging module, which is arranged at the rear end of the second guide rail, the ranging port of the ranging module is aligned with the rear end of the third slider, and the output end of the ranging module is connected to the controller connect; Wherein, the oil pump is connected to the inlet of a buffer through a solenoid valve, the buffer is filled with hydraulic oil, the longitudinal cross-sectional area of the buffer is not less than the longitudinal cross-sectional area of the second guide rail, and the buffer is The outlet of the second guide rail is in communication with the inner end space of the second guide rail, and a flow meter is arranged on the solenoid valve. 2 . The scanning platform for an imaging radiometer according to claim 1 , wherein each of the linear displacement mechanisms is arranged on the T-shaped bracket through a mounting seat, and the driving mechanism is a stepping motor. 3 . , the driving mechanism is drivingly connected with the screw rod through a connecting seat. 3 . The scanning platform for an imaging radiometer according to claim 2 , wherein the longitudinal section of the first sliding block is consistent with the longitudinal section of the inner space of the first guide rail, and the first guide rail has two sides. 4 . A first guide groove is provided on the inner side wall, a first guide block is correspondingly provided on the side wall of the first slider, the first guide block is slidably arranged in the first guide groove, and the first guide block is slidably arranged in the first guide groove, and the A first sealing ring is arranged on the outer periphery of the end of a slider. 4 . The scanning platform for an imaging radiometer according to claim 3 , wherein a threaded hole is formed through the center of the first sliding block along the length direction, and the first sliding block is sleeved through the threaded hole. 5 . It is arranged on the screw rod, and a threaded sealing sleeve is arranged between the threaded hole and the screw rod. 5 . The scanning platform for an imaging radiometer according to claim 4 , wherein the upper end of the first guide rail is sealed with a first cover plate, and a plurality of through holes are opened at the end of the first cover plate; 6 . The second guide rail is disposed at the upper end of the first cover plate, and the inner space of the second guide rail is communicated with the inner space of the first guide rail through the through hole. 6 . The scanning platform for an imaging radiometer according to claim 5 , wherein the longitudinal section of the second slider is consistent with the longitudinal section of the inner space of the second guide rail, and the second guide rail has two sides. A second guide groove is arranged on the inner side wall, a second guide block is correspondingly arranged on the side wall of the second slider, the second guide block is slidably arranged in the second guide groove, and the first guide block is slidably arranged in the second guide groove. The outer periphery of the ends of the two sliding blocks is provided with a second sealing ring. 7 . The scanning platform for an imaging radiometer according to claim 6 , wherein the upper end of the second guide rail is sealed with a second cover plate, the second cover plate is provided with a guide groove, and the first The three sliders are slidably arranged on the guide groove through the guide rod, the slot runs through the center of the second cover plate along the length direction, and the two inner side walls of the slot are provided with a third guide groove A third guide block is correspondingly arranged on the two side walls of the guide rod, and a sealant pad is arranged in the third guide groove, and the third guide block is slidably arranged in the sealant pad. 8 . The scanning platform for an imaging radiometer according to claim 7 , wherein an accommodating box is arranged outside the second guide rail, and an elastic scrolling device is arranged in the accommodating box, and the roll The plate is wound around the outer circumference of the elastic scrolling device, a straightening opening is arranged on the accommodating box, the free end of the rolling plate is connected to the side wall of the end of the guide rod through the straightening opening, and the rolling plate is The width of the plate is larger than the width of the slot, and both sides of the free end of the rolled plate are slidably arranged in the sealing gasket. 9 . The scanning platform for an imaging radiometer according to claim 8 , wherein both ends of the first slider are provided with a first touch switch, and both ends of the second slider are provided with a second touch switch. 10 . A touch switch, a third touch switch is provided at both ends of the third slider, an origin switch is protruded from the end of the second guide rail, and an end switch is protruded from the tail end of the second guide rail. The switch is connected to the controller. 10 . The scanning platform for an imaging radiometer according to claim 9 , wherein the oil tank is arranged on the T-shaped bracket, the oil pump inlet is communicated with the oil outlet of the oil tank, and the The outlet of the oil pump is communicated with the inlet of the buffer through a first solenoid valve, the first solenoid valve is provided with a first flow meter, the inner end of the second guide rail is provided with a calibration oil return port, the The calibration oil return port is communicated with the oil tank oil return port through a second solenoid valve, the second solenoid valve is provided with a second flow meter, and each of the solenoid valves and the flow meter is respectively connected to the controller.

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