CN115343688B - Laser scanning synchronous control system and control method based on polygon mirror - Google Patents
Laser scanning synchronous control system and control method based on polygon mirror Download PDFInfo
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- CN115343688B CN115343688B CN202210979640.6A CN202210979640A CN115343688B CN 115343688 B CN115343688 B CN 115343688B CN 202210979640 A CN202210979640 A CN 202210979640A CN 115343688 B CN115343688 B CN 115343688B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
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Abstract
The invention provides a laser scanning synchronous control system and a control method based on a polygon mirror, which are used for solving the technical problems that the existing light triggering synchronous control has a close detection blind area, laser is easy to branch, and multi-frame single detection images of each reflection surface scanning are difficult to accurately extract for splicing. The system comprises a pulse laser, a synchronous controller, a first receiving detector, a polygon mirror, a continuous laser and a second receiving detector; the control method adopts a continuous laser and a second receiving detector to construct a scanning initial monitoring mechanism, and when the synchronous controller detects that the energy maximum value occurs in the signal sent by the second receiving detector each time, the position of the pulse laser on the current reflecting surface is recorded as a trigger starting point; the synchronous controller counts all the sent trigger pulses, outputs the current trigger pulse sequence number at each trigger starting point, and accurately extracts a multi-frame single detection chart obtained by scanning each reflecting surface of the polygon mirror according to the sequence number.
Description
Technical Field
The invention relates to synchronous control, in particular to a laser scanning synchronous control system and a control method based on a polygon mirror.
Background
The synchronous control is widely applied to laser radar three-dimensional scanning imaging, and the specific working principle is as follows: the pulse laser emits pulse laser to illuminate the target, the return light is received by the receiving detector, the laser radar performs three-dimensional measurement by the pulse laser flight time, and the pulse laser and the receiving detector are synchronously controlled to effectively receive the pulse laser and perform flight time measurement due to extremely fast light speed and short pulse width of the pulse laser.
The light triggering is a common laser radar synchronous control method, as shown in fig. 1, the light triggering synchronous control system comprises a pulse laser 01, a spectroscope 02, a light emitting detector 03, a synchronous controller 04, a receiving detector 05 which are sequentially arranged along a reflection light path of the spectroscope 02, and a turning mirror 06 which is arranged along a transmission light path of the spectroscope 02. The pulse laser 01 separates a beam of pulse laser through the spectroscope 02, receives and monitors the light moment through the light emitting detector 03, and the synchronous controller 04 sends out synchronous square waves to trigger the receiving detector 05 to receive by taking the moment as a trigger starting point. Because there is response delay among the pulse laser 01, the synchronous controller 04 and the receiving detector 05, as shown in fig. 2, the waveform of the pulse laser 01 is 0a, the waveform of the receiving detector 05 is 0b, and if the target distance is too close, the receiving detector 05 cannot be started in time, so that a close-range detection blind area exists. As shown in fig. 3, when the emitted laser of the pulse laser 01 is emitted to the corner of the rotating mirror 06, the laser is easy to diverge, resulting in failure of the scanning and redundant stray light. Meanwhile, the rotating mirror 06 is composed of a multi-surface reflecting mirror and is driven to rotate by a motor. The scanning process of each surface of the rotating mirror 06 is divided into a plurality of single scans, and each single scan obtains a frame of single detection image, so each surface scan can obtain a plurality of frames of single detection images, and a frame of scanning image is formed after the single detection images are spliced. However, since the corresponding relationship between the laser time sequence and the angle of the rotating mirror 06 cannot be established, the corresponding laser light emitting time when each surface starts scanning cannot be judged, and the area of each surface of the rotating mirror 06 and the included angle between every two surfaces are unequal due to the errors existing in the processing and assembling of the rotating mirror 06, and the errors existing in the stability of the rotation speed of the motor are added, the number of lasers reflected by each surface of the rotating mirror 06 is unequal in the scanning process, so that the number of corresponding single detection images is also unequal. Therefore, in the multi-frame single-shot probe map obtained in one scanning operation, it is difficult to accurately extract the multi-frame single-shot probe map obtained by each surface scanning for stitching.
Disclosure of Invention
The invention aims to solve the technical problems that the short-distance detection blind area exists in the existing light triggering synchronous control, laser is easy to branch, and multiple frames of single detection images scanned by each reflecting surface are difficult to accurately extract for splicing, and provides a laser scanning synchronous control system and a laser scanning synchronous control method based on a polygon mirror.
In order to achieve the above object, the technical solution of the present invention is:
the laser scanning synchronous control system based on the polygon mirror is characterized by comprising a pulse laser, a synchronous controller, a first receiving detector, the polygon mirror, a continuous laser and a second receiving detector;
any reflecting surface of the polygon mirror is positioned on a pulse laser light path emitted by the pulse laser, and the other different reflecting surfaces of the polygon mirror are positioned on a continuous laser light path emitted by the continuous laser; the pulse laser reflected by the reflecting surface where the pulse laser is positioned is used for scanning the target to be detected, and the first receiving detector is positioned on a reflecting light path of the target to be detected; the second receiving detector is positioned on a reflection light path of the reflection surface where the continuous laser is positioned, and the output end of the second receiving detector is connected with the input end of the synchronous controller;
the continuous laser emitted by the continuous laser device is reflected by the corresponding reflecting surface of the polygon mirror and then reaches the second receiving detector, and the second receiving detector receives the reflected continuous laser signal and sends the continuous laser signal to the synchronous controller;
the output end of the synchronous controller is respectively connected with the pulse laser and the first receiving detector; and the synchronous controller is used for receiving the signal sent by the second receiving detector and judging whether the energy maximum value is reached, when the energy maximum value is reached, the synchronous controller sends out a group of sequence square waves which are respectively sent to the pulse laser and the first receiving detector, and the pulse laser and the first receiving detector are synchronously controlled to respectively emit pulse laser and detect imaging.
The invention also provides a laser scanning synchronous control method based on the polygon mirror, which is characterized by comprising the following steps:
1 determining the position and angle of the continuous laser and the second receiving detector
When the pulse laser emitted by the pulse laser is positioned on any reflecting surface of the polygon mirror, stopping rotating the polygon mirror; transmitting continuous laser to different reflecting surfaces of the polygon mirror by using the continuous laser, continuously adjusting the angles and the positions of the continuous laser and the second receiving detector on the corresponding reflecting surfaces, and stopping adjusting and fixing the positions and the angles of the continuous laser and the second receiving detector when the synchronous controller detects that the signal transmitted by the second receiving detector is the maximum energy value;
2, synchronous control
The polygon mirror rotates continuously, so that continuous laser emitted by the continuous laser is reflected by the corresponding reflecting surface of the polygon mirror and then enters the second receiving detector, and the second receiving detector sends signals to the synchronous controller in real time; when the synchronous controller detects that the signal sent by the second receiving detector has the maximum energy value every time, the position of the pulse laser on the current reflecting surface is recorded as a trigger starting point; at the triggering start point of each reflecting surface, the synchronous controller sends out a corresponding group of sequence square waves; each group of sequence square waves comprise sequence square waves with the same frequency and output to a pulse laser and sequence square waves output to a first receiving detector; the total time of the sequence square waves output to the pulse laser in each group of sequence square waves is less than or equal to the time from the start of receiving the pulse laser to the stop of receiving the pulse laser of the reflecting surface corresponding to the polygon mirror, and the number of trigger pulses in each group of sequence square waves is the same;
simultaneously, the synchronous controller counts the trigger pulses in all the sequence square waves, and the sequence number of the trigger pulse is increased by 1 when one trigger pulse is sent out; the synchronous controller outputs the sequence number of the current trigger pulse at the trigger starting point of each reflecting surface of the polygon rotary mirror, and can accurately extract a multi-frame single detection image shot between two adjacent trigger starting points according to the sequence number of the current trigger pulse, namely the multi-frame single detection image shot by the current reflecting surface is spliced to obtain a frame of scanning image;
and 3, splicing the obtained scanning images of each frame according to time sequence to obtain a dynamic scanning image of the target to be detected.
Further, the step 1 is specifically: when the pulse laser emitted by the pulse laser is positioned on any reflecting surface of the polygon mirror within 1/2 of the current starting point position of the reflecting surface, the angles and the positions of the continuous laser and the second receiving detector on the corresponding reflecting surfaces are continuously adjusted, and when the synchronous controller detects that the signal sent by the second receiving detector is the maximum energy value, the adjustment and the fixing of the positions and the angles of the continuous laser and the second receiving detector are stopped.
Further, the step 1 is specifically: when the pulse laser emitted by the pulse laser is positioned at the position 1/10000 to 1/1000 of the position of any reflecting surface of the polygon mirror from the starting point of the current reflecting surface, the angles and the positions of the continuous laser and the second receiving detector on the corresponding reflecting surfaces are continuously adjusted, and when the synchronous controller detects that the signal sent by the second receiving detector is the maximum energy value, the adjustment and the fixing of the positions and the angles of the continuous laser and the second receiving detector are stopped.
Further, in step 2 ], the sequence square wave output to the pulse laser and the sequence square wave output to the first receiving detector in each group of sequence square waves are respectively provided with a trigger delay t s1 And trigger delay t s2 And trigger delay t s1 And trigger delay t s2 The delay of the (c) is adjustable.
Further, in step 2 ], the counting of trigger pulses in all the sequence square waves by the synchronous controller is specifically:
the synchronization controller counts all trigger pulses in the sequence square wave output to the pulse laser or counts all trigger pulses in the sequence square wave output to the first receiving detector.
The invention has the beneficial effects that:
1. according to the laser scanning synchronous control method based on the polygon mirror, when the synchronous controller detects that the energy maximum value occurs in the signal sent by the second receiving detector every time, the position of the pulse laser on the current reflecting surface is recorded as the triggering starting point for laser receiving and transmitting, and the pulse laser receiving and transmitting can be accurately started at the fixed position of each reflecting surface of the polygon mirror.
2. According to the laser scanning synchronous control method based on the polygon mirror, the synchronous controller counts all trigger pulses in the sequence square waves output to the first receiving detector, the sequence number of the current trigger pulse is output at the trigger starting point, and according to the sequence number of the current trigger pulse, a multi-frame single detection image shot on the current reflecting surface of the polygon mirror can be accurately extracted, and then one frame of scanning image is obtained through splicing.
3. The laser scanning synchronous control method based on the polygon mirror provided by the invention has the advantages that the total time of outputting the pulse laser in each group of sequence square waves is set to be smaller than the time from the start of receiving the pulse laser to the stop of receiving the pulse laser in the one-time scanning process of the polygon mirror, so that the phenomenon that the pulse laser is branched when being emitted to the corner of the polygon mirror, and the scanning failure is avoided.
4. According to the laser scanning synchronous control method based on the polygon mirror, the sequence square waves output to the pulse laser in each group of sequence square waves are set in the synchronous controller to be identical to the sequence square waves output to the first receiving detector in frequency, so that the receiving and transmitting synchronization of the pulse laser is ensured.
5. According to the laser scanning synchronous control method based on the polygon mirror, the number of trigger pulses in each group of sequence square waves is set to be the same in the synchronous controller, so that the number of single detection images received on each reflecting surface of the polygon mirror can be ensured to be the same.
6. According to the laser scanning synchronous control method based on the polygon mirror, the sequence square waves output to the pulse laser and the sequence square waves output to the first receiving detector in each group of sequence square waves are set to be time-delay-adjustable sequence square waves in the synchronous controller, so that the pulse laser emission time delay and the receiving time delay are arbitrarily adjustable, the response time delay between the pulse laser and the first receiving detector can be eliminated, and then the short-distance detection blind area is eliminated.
7. The laser scanning synchronous control system based on the polygon mirror provided by the invention is provided with the continuous laser and the second receiving detector, so that a scanning starting monitoring mechanism is formed, and the position of pulse laser emitted by the pulse laser on the polygon mirror can be monitored in real time, and the scanning starting position is marked.
Drawings
FIG. 1 is a schematic diagram of a prior art light-triggered synchronous control;
FIG. 2 is a schematic diagram of waveforms of a short-distance detection blind area caused by response delay in light triggering synchronous control;
FIG. 3 is a schematic diagram showing the reflection and branching of the laser at the corner of the turning mirror in the optical triggering synchronous control;
FIG. 4 is a schematic diagram of a laser scanning synchronization control system based on a polygon mirror according to an embodiment of the present invention;
fig. 5 is a timing diagram of synchronization control in an embodiment of the method of the present invention.
Specific reference numerals are as follows:
01-pulse laser; 02-spectroscope; 03-outputting a light detector; 04-synchronous controller; 05-receiving a detector; 06-turning mirror;
1-a pulsed laser; 2-a synchronous controller; 3-a first receiving detector; 4-a polygon mirror; a 5-continuous laser; 6-a second receiving detector.
Detailed Description
To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
The laser scanning synchronous control system based on the polygon mirror comprises a pulse laser 1, a synchronous controller 2, a first receiving detector 3, a polygon mirror 4, a continuous laser 5 and a second receiving detector 6 as shown in fig. 4. The continuous laser 5 and the second receiving detector 6 form a scanning start monitoring system for monitoring the position of the pulse laser emitted by the pulse laser 1 on the polygon mirror 4 in real time and marking the scanning start position. The polygon mirror 4 includes at least three reflection surfaces of the same size and the same material, and the polygon mirror 4 in this embodiment includes six reflection surfaces of the same size. The continuous laser emitted by the continuous laser 5 and the pulse laser emitted by the pulse laser 1 are respectively positioned on different reflecting surfaces of the polygon mirror 4, as shown in fig. 4, the reflecting surface on which the pulse laser emitted by the pulse laser 1 is positioned is denoted as a first reflecting surface, and the other reflecting surfaces are sequentially a second reflecting surface, a third reflecting surface, a fourth reflecting surface, a fifth reflecting surface and a sixth reflecting surface along the anticlockwise direction, so that the third reflecting surface is positioned on a continuous emitting laser light path of the continuous laser 5; in other embodiments, any one of the second reflecting surface, the fourth reflecting surface, the fifth reflecting surface, and the sixth reflecting surface may be located on the continuous outgoing laser light path of the continuous laser 5. The second receiving detector 6 is located on the reflection optical path of the reflection surface of the polygon mirror 4 corresponding to the continuous laser 5, and is configured to receive the reflected continuous laser signal and send the continuous laser signal to the synchronization controller 2. And the synchronous controller 2 is used for receiving the signal sent by the second receiving detector 6 and judging whether the energy maximum value is reached, and when the energy maximum value is reached, the synchronous controller 2 sends out a group of sequence square waves to be respectively sent to the pulse laser 1 and the first receiving detector 3. The group of sequence square waves comprises a sequence square wave output to the pulse laser 1 and a sequence square wave output to the first receiving detector 3, and the sequence square waves are used for synchronously controlling the pulse laser 1 and the first receiving detector 3 to work on the corresponding reflecting surfaces of the polygon mirror 4. The pulse laser reflected by the reflecting surface where the pulse laser is positioned is used for scanning the target to be detected, and the first receiving detector 3 is positioned on the reflecting light path of the target to be detected and used for receiving the reflecting light of the target to be detected to complete imaging of the target to be detected.
The following describes a laser scanning synchronous control method based on a polygon mirror through a specific embodiment, and specifically comprises the following steps:
1 determining the position and angle of the continuous laser 5 and the second receiving detector 6
When the pulse laser light emitted from the pulse laser 1 is located on any reflecting surface of the polygon mirror 4, stopping rotation of the polygon mirror 4; continuously adjusting the angles and the positions of the continuous laser 5 and the second receiving detector 6 on the corresponding reflecting surfaces, and stopping adjusting and fixing the positions and the angles of the continuous laser 5 and the second receiving detector 6 when the synchronous controller 2 detects that the signal sent by the second receiving detector 6 is the maximum energy value; in order to make the first receiving detector 3 obtain more detection images on each reflecting surface, the angles and positions of the continuous laser 5 and the second receiving detector 6 on the corresponding reflecting surfaces can be adjusted when the distance between each reflecting surface and the current reflecting surface starting position is 1/2 or less, and preferably, the angles and positions of the continuous laser 5 and the second receiving detector 6 on the corresponding reflecting surfaces can be adjusted when the pulse laser light emitted by the pulse laser 1 is positioned at the position between 1/10000 and 1/1000 from the current reflecting surface starting position on any reflecting surface of the polygon mirror 4. Since the reflecting surfaces of the polygon mirror 4 are the same in size and the same in material, when the pulse laser light emitted from the pulse laser 1 is located at the corresponding position of each reflecting surface, the second receiving detector 6 can receive the continuous laser signal with the corresponding maximum energy.
2, synchronous control
In the scanning process, the polygon mirror 4 is driven by a motor to continuously rotate, so that continuous laser emitted by the continuous laser 5 is reflected by a corresponding reflecting surface of the polygon mirror 4 and then is incident to the second receiving detector 6, and the second receiving detector 6 sends a signal to the synchronous controller 2 in real time; when the synchronous controller 2 detects that the signal sent by the second receiving detector 6 has the maximum energy value every time, the position of the pulse laser on the current reflecting surface is recorded as the trigger starting point. At the triggering start point of each reflecting surface, the synchronous controller 2 sends out a corresponding group of sequence square waves along with the scanningThe synchronous controller 2 sends out corresponding groups of sequence square waves by continuously rotating the polygon mirror 4 during the drawing process. Each set of sequence square waves comprises a sequence square wave output to the pulsed laser 1 and a sequence square wave output to the first receiving detector 3. Each of the sequence square waves includes a plurality of trigger pulses, as shown in fig. 5, the waveform of the sequence square wave input to the synchronous controller 2 by the second receiving detector 6 is denoted as a, the waveform of the sequence square wave output to the pulse laser 1 by the synchronous controller 2 is denoted as b, the waveform of the sequence square wave output to the first receiving detector 3 by the synchronous controller 2 is denoted as c, and in order to ensure the synchronization of the receiving and transmitting of the pulse laser, the sequence square wave output to the pulse laser 1 and the sequence square wave output to the first receiving detector 3 are set to have the same frequency. In the synchronous control process, in order to prevent the pulse laser 1 from emitting pulse laser at the corner position of the polygon mirror 4 to obtain branched light and further cause scanning failure, the invention sets the total time t' of the sequence square waves output to the pulse laser 1 in each group of sequence square waves to be less than or equal to the time t from the start of receiving the pulse laser to the stop of receiving the pulse laser in one scanning process of the corresponding reflecting surface of the polygon mirror 4. In this embodiment, the total scanning time of one reflecting surface of the polygon mirror 4 is 50ms, that is, the time t from the start of receiving the pulse laser to the stop of receiving the pulse laser in one scanning process of the corresponding reflecting surface is 50ms, the number of trigger pulses in the sequence square wave output to the pulse laser 1 is set to 200, the trigger pulse period is 100us, and the total time t' of the sequence square wave output to the pulse laser 1 is 20ms, which is less than the time from the start of receiving the pulse laser to the stop of receiving the pulse laser in one scanning process of the corresponding reflecting surface. The invention outputs the trigger delay t of the sequence square wave of the pulse laser 1 in each group of sequence square waves in the synchronous controller 2 s1 And a trigger delay t of the sequence square wave output to the first receiving detector 3 s2 The time delay is set to be a sequence square wave with adjustable time delay, so that the transmitting time delay and the receiving time delay of the pulse laser are arbitrarily adjustable, the response time delay between the pulse laser 1 and the first receiving detector 3 can be eliminated, and then the short-distance detection blind area is eliminated. In addition, due to errors in processing and assembling the polygon mirror 4, the area of each reflecting surface of the polygon mirror 4 and the reflection of each twoThe included angles between the surfaces are unequal, and the errors of the rotation speed stability of the motor driving the polygon mirror 4 are added, so that the number of laser beams reflected by each reflecting surface of the polygon mirror 4 is unequal in the scanning process, and the number of trigger pulses output to the pulse laser 1 and the number of trigger pulses output to the first receiving detector 3 in each group of sequence square waves are set in the synchronous controller 2. When each trigger pulse triggers the pulse laser 1 and the first receiving detector 2 to work, a single detection image of one frame can be obtained, the quantity of detection images received on each reflecting surface of the polygon mirror 4 can be ensured to be the same, and 200 single detection images can be obtained in the scanning process of each reflecting surface of the polygon mirror 4.
Meanwhile, the synchronous controller 2 counts the trigger pulses in all the sequence square waves, wherein the trigger pulses output to the pulse laser 1 in all the sequence square waves can be counted, and the trigger pulses output to the first receiving detector 3 in all the sequence square waves can be counted, in this embodiment, the trigger pulses output to the pulse laser 1 are counted, and each time the pulse laser 1 sends a trigger pulse, the sequence number of the trigger pulse is increased by 1; the synchronous controller 2 outputs the sequence number of the current trigger pulse at the trigger starting point of each reflecting surface of the polygon mirror 4, and the position between two adjacent trigger starting points can be accurately extracted according to the sequence number of the current trigger pulse, namely, a multi-frame single-time detection image obtained by multiple times of shooting by the first receiving detector 3 on the current reflecting surface of the polygon mirror is spliced to obtain a frame of scanning image;
and 3, splicing the obtained scanning images of each frame according to time sequence to obtain a dynamic scanning image of the target to be detected.
The invention adopts a continuous laser 5 and a second receiving detector 6 to construct a scanning start monitoring mechanism, when the synchronous controller 2 detects that the energy maximum value occurs to the signal sent by the second receiving detector 6 each time, the position of the pulse laser on the current reflecting surface is recorded as the trigger starting point, and two paths of sequence square waves with the same frequency are sent out by the synchronous controller 2 to synchronously control the laser receiving and transmitting, wherein the total time t' of the sequence square waves output to the pulse laser 1 in each group of sequence square waves is less than or equal to the time t from the start of receiving the pulse laser to the stop of receiving the pulse laser in one scanning process of the current reflecting surface. The synchronous controller counts all the sent trigger pulses, outputs the current trigger pulse sequence number at each trigger starting point, and accurately extracts a multi-frame single detection chart corresponding to each surface scanning process of the polygon mirror 4 according to the sequence numbers.
The foregoing description is only for the purpose of illustrating the technical solution of the present invention, but not for the purpose of limiting the same, and it will be apparent to those of ordinary skill in the art that modifications may be made to the specific technical solution described in the foregoing embodiments, or equivalents may be substituted for parts of the technical features thereof, without departing from the spirit of the technical solution of the present invention.
Claims (6)
1. A laser scanning synchronous control system based on a polygon mirror is characterized in that: the device comprises a pulse laser (1), a synchronous controller (2), a first receiving detector (3), a polygon mirror (4), a continuous laser (5) and a second receiving detector (6);
any reflecting surface of the polygon mirror (4) is positioned on a pulse laser light path emitted by the pulse laser (1), and another different reflecting surface of the polygon mirror (4) is positioned on a continuous laser light path emitted by the continuous laser (5); the pulse laser reflected by the reflecting surface where the pulse laser is positioned is used for scanning a target to be detected, and the first receiving detector (3) is positioned on a reflecting light path of the target to be detected; the second receiving detector (6) is positioned on a reflection light path of a reflection surface where the continuous laser is positioned, and the output end of the second receiving detector (6) is connected with the input end of the synchronous controller (2);
the continuous laser emitted by the continuous laser (5) is reflected by the corresponding reflecting surface of the polygon mirror (4) and then reaches the second receiving detector (6), and the second receiving detector (6) receives the reflected continuous laser signal and sends the continuous laser signal to the synchronous controller (2);
the output end of the synchronous controller (2) is respectively connected with the pulse laser (1) and the first receiving detector (3); the synchronous controller (2) is used for receiving signals sent by the second receiving detector (6) and judging whether the energy maximum value is reached, when the energy maximum value is reached, the synchronous controller (2) sends out a group of sequence square waves which are respectively sent to the pulse laser (1) and the first receiving detector (3), and the synchronous control pulse laser (1) and the first receiving detector (3) respectively perform pulse laser emission and detection imaging.
2. A laser scanning synchronization control method based on a polygon mirror, based on the laser scanning synchronization control system based on a polygon mirror according to claim 1, characterized by comprising the steps of:
1 determining the position and angle of the continuous laser (5) and the second receiving detector (6)
When the pulse laser emitted by the pulse laser (1) is positioned on any reflecting surface of the polygon mirror (4), stopping rotating the polygon mirror (4); transmitting continuous laser to different reflecting surfaces of the polygon mirror (4) by using the continuous laser (5), continuously adjusting the angles and the positions of the continuous laser (5) and the second receiving detector (6) on the corresponding reflecting surfaces, and stopping adjusting and fixing the positions and the angles of the continuous laser (5) and the second receiving detector (6) when the synchronous controller (2) detects that the signal transmitted by the second receiving detector (6) is the maximum energy value;
2, synchronous control
The polygon mirror (4) rotates continuously, so that continuous laser emitted by the continuous laser (5) is reflected by a corresponding reflecting surface of the polygon mirror (4) and then enters the second receiving detector (6), and the second receiving detector (6) sends signals to the synchronous controller (2) in real time; when the synchronous controller (2) detects that the signal sent by the second receiving detector (6) has the maximum energy value every time, the position of the pulse laser on the current reflecting surface is recorded as a trigger starting point; at the triggering start point of each reflecting surface, the synchronous controller (2) sends out a corresponding group of sequence square waves; each group of sequence square waves comprises sequence square waves with the same frequency and output to the pulse laser (1) and sequence square waves output to the first receiving detector (3); the total time of the sequence square waves output to the pulse laser (1) in each group of sequence square waves is less than or equal to the time from the start of receiving the pulse laser to the stop of receiving the pulse laser of the corresponding reflecting surface of the polygon mirror (4), and the number of trigger pulses of each group of sequence square waves is the same;
simultaneously, the synchronous controller (2) counts the trigger pulses in all the sequence square waves, and the sequence number of the trigger pulse is increased by 1 when one trigger pulse is sent out; the synchronous controller (2) outputs the sequence number of the current trigger pulse at the trigger starting point of each reflecting surface of the polygon rotary mirror (4), and extracts a multi-frame single detection image shot between two adjacent trigger starting points according to the sequence number of the current trigger pulse, so as to splice and obtain a frame of scanning image;
and 3, splicing the obtained scanning images of each frame according to time sequence to obtain a dynamic scanning image of the target to be detected.
3. The laser scanning synchronization control method based on the polygon mirror according to claim 2, wherein:
the step 1 is specifically as follows: when the pulse laser emitted by the pulse laser (1) is positioned on any reflecting surface of the polygon mirror (4) within 1/2 of the current starting point position of the reflecting surface, the angles and the positions of the continuous laser (5) and the second receiving detector (6) on the corresponding reflecting surfaces are continuously adjusted, and when the synchronous controller (2) detects that the signal sent by the second receiving detector (6) is the maximum energy value, the adjustment and the fixing of the positions and the angles of the continuous laser (5) and the second receiving detector (6) are stopped.
4. The laser scanning synchronization control method based on the polygon mirror according to claim 2, wherein:
the step 1 is specifically as follows: when the pulse laser emitted by the pulse laser (1) is positioned at the position 1/10000 to 1/1000 of the position of any reflecting surface of the polygon mirror (4) away from the starting point of the current reflecting surface, the angles and the positions of the continuous laser (5) and the second receiving detector (6) on the corresponding reflecting surfaces are continuously adjusted, and when the synchronous controller (2) detects that the signal sent by the second receiving detector (6) is the maximum energy value, the adjustment and the fixing of the positions and the angles of the continuous laser (5) and the second receiving detector (6) are stopped.
5. The laser scanning synchronization control method based on the polygon mirror according to any one of claims 2 to 4, characterized in that:
in step 2 ], the sequence square wave output to the pulse laser (1) and the sequence square wave output to the first receiving detector (3) in each group of sequence square waves are respectively provided with a trigger delayAnd trigger delay +.>And trigger delay +.>And trigger delayThe delay of the (c) is adjustable.
6. The laser scanning synchronization control method based on the polygon mirror as claimed in claim 5, wherein:
in step 2, the synchronous controller (2) counts trigger pulses in all the sequence square waves specifically as follows:
the synchronization controller (2) counts all trigger pulses in the sequence square wave output to the pulse laser (1) or counts all trigger pulses in the sequence square wave output to the first receiving detector (3).
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