CN113405993B - Device and method for measuring two-dimensional impulse of irregular target driven by laser ablation - Google Patents

Abstract

The application provides an irregular target two-dimensional impulse measuring device of laser ablation drive, includes: the device comprises a laser emitting device for emitting laser, a focusing lens for focusing the laser, a target fixing tool for placing a target sample, a suspension device for suspending the target fixing tool, a first displacement measuring device arranged along the axis direction of the laser emission and a second displacement measuring device arranged perpendicular to the axis direction of the laser emission; the laser emitting device, the focusing lens and the target fixing tool are sequentially and transversely arranged along the same horizontal line; the target fixing tool can freely swing under the action of impulse generated by laser ablation of a target sample; the first displacement measuring device and the second displacement measuring device are located on the same horizontal plane and are respectively used for measuring the swinging amount of the target fixing tool in the direction of the first displacement measuring device and the second displacement measuring device. The laser ablation drive irregular target impulse generating device can measure the impulse generated by the irregular target driven by laser ablation in two vertical directions of a horizontal plane simultaneously.

Description

Device and method for measuring two-dimensional impulse of irregular targets driven by laser ablation

technical field

The present application relates to the technical field of laser ablation, in particular to a device and method for measuring two-dimensional impulse of an irregular target driven by laser ablation.

Background technique

Laser ablation drive technology is widely used in the fields of laser propulsion, space debris removal, and ultra-high-speed launch. The application of this technology depends on the research describing the law of impulse generation in the interaction between laser and matter. At present, research in this field mainly drives micro-impulse measurement systems through laser ablation. Existing measurement systems can only measure one-dimensional impulse, so the expected impulse direction can only be on the measurement axis of the measurement system for a plane or regular-shaped target whose expected impulse direction is known. However, in the fields of laser ablation drive to remove space debris, laser ablation drive to deflect asteroids and other fields, the targets of laser ablation drive are mostly irregular-shaped targets, and the direction of its impulse cannot be predicted before the impulse measurement is performed. As a result, the impulse perpendicular to the measurement axis cannot be measured when using the traditional one-dimensional measurement system, which leads to deviations in the experimental results and cannot truly reflect the impulse obtained by the target under the action of the laser. To this end, the present application proposes a device and method for measuring two-dimensional impulse of an irregular target driven by laser ablation.

Contents of the invention

The purpose of the present application is to address the above problems and provide a two-dimensional impulse measurement device and method for driving irregular targets by laser ablation.

In the first aspect, the present application provides a laser ablation-driven irregular target two-dimensional impulse measurement device, including: a laser emitting device for emitting laser light, a focusing lens for focusing laser light, and a target fixing tool for placing target samples . A suspension device for suspending the target fixing tool, a first displacement measuring device arranged along the axis direction of laser emission, and a second displacement measurement device arranged perpendicular to the axis direction of laser emission;

The laser emitting device, the focusing lens, and the target fixing tool are sequentially arranged laterally along the same horizontal line; the target fixing tool can swing freely under the action of the impulse generated by laser ablation of the target sample; the first The displacement measuring device and the second displacement measuring device are located on the same horizontal plane, and they are respectively used to measure the swing amount of the target fixing tool in their respective directions.

According to the technical solutions provided in some embodiments of the present application, the target fixing tool is a hollow cube structure; the target fixing tool has a placement opening on a side facing the focusing lens.

According to the technical solution provided in some embodiments of the present application, the suspension device includes a suspension bracket and four suspension ropes of equal length; the four suspension ropes are respectively fixedly connected to the top four corners of the target fixing tool , and the free ends of the four suspension ropes are fixed at the same point on the suspension bracket.

According to the technical solutions provided in some embodiments of the present application, the outer surfaces of the three sides of the target fixing tool without the placement opening are respectively smooth planes.

According to the technical solution provided by some embodiments of the present application, the first displacement measuring device and the second displacement measuring device are respectively laser displacement sensors.

In a second aspect, the present application provides a method for measuring two-dimensional impulse of an irregular target driven by laser ablation using the above-mentioned two-dimensional impulse measurement device for driving an irregular target by laser ablation. The method includes the following steps:

Obtaining the maximum swing amount dx of the target fixing tool in the first direction and the maximum swing amount dy in the second direction by the first displacement measuring device and the second displacement measuring device;

According to the maximum swing dx of the target fixing tool in the first direction, an impulse calculation algorithm is used to calculate the impulse value Ix of the target sample in the first direction;

According to the maximum swing amount dy of the target fixing tool in the second direction, an impulse calculation algorithm is used to calculate the impulse value Iy of the target sample in the second direction.

According to the technical solution provided in some embodiments of the present application, according to the maximum swing amount d of the target fixing tool in a certain direction, the method of calculating the impulse value I of the target sample in this direction using an impulse calculation algorithm includes:

Calculate the swing angle θ of the target fixing tool along this direction:

θ = arcsin(d/L);

Calculate the height change h of the target fixing tool in the vertical direction:

h=L(1-cosθ)=L(1-cos(arcsin(d/L)));

According to the law of conservation of mechanical energy, calculate the speed v of the fixed tooling of the target:

According to the momentum theorem, calculate the impulse I of the target sample in this direction:

Among them, g is the acceleration of gravity; m is the total mass of the target sample and the target fixture; L is the suspension height of the target fixture; d is the maximum swing amount of the target fixture in a certain direction.

Compared with the prior art, the present application has the beneficial effect: the laser ablation drives the irregular target two-dimensional impulse measurement device, and the target is fixed by setting the laser emitting device, the focusing lens and the target fixing tool which are sequentially arranged along the same horizontal line The tooling is suspended on the suspension device, so that the target sample placed in the target fixing tooling can freely swing and generate displacement under the action of the impulse generated by laser ablation of the target sample; by setting the first displacement measuring device along the axis of laser emission , and set a second displacement measuring device along the axis perpendicular to the laser emission, when the target fixing tool swings freely, it can measure the displacement of the target fixing tool in the laser action direction and perpendicular to the laser action direction in real time, so as to calculate the target fixing The impulse obtained by the tooling in these two directions is to obtain the two-dimensional impulse of the target sample driven by laser ablation.

Description of drawings

FIG. 1 is a schematic structural diagram of a two-dimensional impulse measurement device for laser ablation driven irregular targets provided in Example 1 of the present application;

FIG. 2 is a schematic structural diagram of the suspension device of the laser ablation driven irregular target two-dimensional impulse measurement device provided in Embodiment 1 of the present application;

Fig. 3 is a test schematic diagram of the method for measuring the two-dimensional impulse of an irregular target driven by laser ablation provided in Example 2 of the present application.

The text labels in the figure are expressed as:

1. Laser emitting device; 2. Focusing lens; 3. Target fixing tool; 4. First displacement measuring device; 5. Second displacement measuring device; 6. Hoisting bracket; 7. Suspension rope.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the application, the application will be described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the application. .

Example 1

Please refer to Fig. 1, this embodiment provides a laser ablation driven irregular target two-dimensional impulse measurement device, including: a laser emitting device 1 for emitting laser light, a focusing lens 2 for focusing laser light, and a target sample for placing The target fixing tool 3, the suspension device for suspending the target fixing tool 3, the first displacement measuring device 4 arranged along the axis direction of laser emission, and the second displacement measuring device arranged perpendicular to the axis direction of laser emission 5.

The laser emitting device 1, the focusing lens 2 and the target fixing tooling 3 are sequentially arranged laterally along the same horizontal line; as shown in FIG. The axial direction is the y direction; the laser emitting device 1, the focusing lens 2 and the target fixing tooling 3 are sequentially arranged along the positive direction of the x-axis; the laser emitted by the laser emitting device 1 is focused by the focusing lens 2 The post-irradiation is on the target sample located in the target fixing tool 3; the target fixing tool 3 can swing freely under the action of the impulse generated by laser ablation of the target sample; the first displacement measuring device 4 and The second displacement measuring device 5 is located on the same horizontal plane, as in Fig. 1, the first displacement measuring device 4 is arranged on the x-axis and is located on the side of the target fixing tool 3 away from the focusing lens 2; The second displacement measuring device 5 is arranged on the y-axis; the first displacement measuring device 4 and the second displacement measuring device 5 are used to measure the position of the target fixing tooling 3 in the x-axis direction and the y-axis direction respectively. swing amount.

Further, the target fixing tool 3 is a hollow cube structure; the target fixing tool 3 is provided with a placement opening on the side facing the focusing lens 2; the placement opening is used to put the target sample into the target fixing tool. In the tooling 3, an irradiation entrance is also provided for the focused laser.

Please further refer to Fig. 2, described suspension device comprises suspension bracket 6 and four suspension ropes 7 equal in length; Described suspension bracket 6 comprises the upright column that is arranged perpendicular to horizontal plane and the cross column that is vertically arranged on the top of described upright column; Four said suspension ropes 7 are respectively fixedly connected at the top four corners of said target fixing tooling 3, and the free ends of four said suspension ropes 7 are fixed on the same point on the horizontal column of said hoisting bracket 6; The method of suspending the target fixing tool 3 by a rope system composed of four suspension ropes 7, so that the target fixing tool 3 can freely swing in all directions and is not easy to rotate during the laser ablation driving test .

Further, the target fixing tool 3 of the cube structure has a top surface, a bottom surface and four sides, wherein the side facing the focusing lens 2 is the side with the placement opening, and the remaining three sides are The outer surfaces are smooth planes respectively, so as to facilitate the displacement measurement of the first displacement measuring device 4 and the second displacement measuring device 5 .

Further, the first displacement measuring device 4 and the second displacement measuring device 5 are respectively laser displacement sensors; the first displacement measuring device 4 and the second displacement measuring device 5 are respectively connected to a controller; It is used to transmit the measured data to the controller, and the controller calculates the corresponding direction impulse according to the received displacement measurement data.

The laser ablation drive irregular target two-dimensional impulse measurement device provided in this embodiment, when in use, place the target sample in the target fixing tool 3, control the laser emitting device 1 to emit laser, and the emitted laser is focused after passing through the focusing lens 2 On the target sample, the plasma plume is generated by ablating the surface of the target sample, that is, the driving impulse is generated, so that the target fixing tool 3 drives the four suspension ropes 7 to swing freely under the action of the impulse, so that the x-axis and y-axis direction; through the first displacement measuring device 4 and the second displacement measuring device 5, respectively record the displacement change process of the target fixing tool 3 in the x-axis direction and the y-axis direction, and select its position in the x-axis direction and y-axis direction The maximum offset distance in the direction, and finally calculate the impulse in the x-axis direction and y-axis direction.

The laser ablation drive irregular target two-dimensional impulse measurement device provided in this embodiment is provided with a laser emitting device, a focusing lens, and a target fixing tool that are sequentially arranged along the same horizontal line, and the target fixing tool is suspended on the suspension device, so that The target sample placed in the target fixing fixture can freely swing and generate displacement under the action of the impulse generated by laser ablation of the target sample; by setting the first displacement measuring device along the axis direction of laser emission, and along the direction perpendicular to the axis direction of laser emission Set the second displacement measuring device, when the target fixing tool swings freely, it can measure the displacement of the target fixing tool in the direction of laser action and perpendicular to the direction of laser action in real time, so as to calculate the impulse obtained by the target fixing tool in these two directions , that is, to obtain the two-dimensional impulse of the target sample under the driving action of laser ablation.

Example 2

This embodiment provides a method for measuring the two-dimensional impulse of an irregular target driven by laser ablation. The device for measuring the two-dimensional impulse of an irregular target driven by laser ablation described in Embodiment 1 is used, and the method includes the following steps:

Obtain the total mass of the target sample and target fixture, and record it as m;

Obtain the suspension height of the target fixing tool and record it as L;

Start the test test: control the laser emitting device to emit laser, the laser is focused on the target sample after passing through the focusing lens to generate a driving impulse, so that the target fixing tool can swing freely;

The displacement changes of the target fixing tool in the first direction (ie, the x-axis direction) and the second direction (ie, the y-axis direction) are recorded in real time by the first displacement measuring device and the second displacement measuring device, and the obtained The maximum swing amount dx of the target fixing tool in the x-axis direction and the maximum swing amount dy in the y-axis direction;

According to the maximum swing amount dx of the target fixing tool in the x-axis direction, an impulse calculation algorithm is used to calculate the impulse value Ix of the target sample in the x-axis direction;

According to the maximum swing amount dy of the target fixing tool in the y-axis direction, an impulse calculation algorithm is used to calculate the impulse value Iy of the target sample in the y-axis direction.

Next, the calculation process of the impulse calculation algorithm will be described in detail.

Please refer to Figure 3, set the maximum swing amount d of the target fixing tool in a certain direction, then use the impulse calculation algorithm to calculate the target sample in this direction according to the maximum swing amount d of the target fixing tool in a certain direction Methods for Impulse Value I include:

(1) Calculate the swing angle θ of the target fixing tool along this direction, and according to the sine formula sinθ=d/L, then it can be obtained:

θ = arcsin(d/L);

(2) Calculate the height change h of the target fixing tool in the vertical direction, according to the cosine formula cosθ=(L-h)/L, then it can be obtained:

h=L(1-cosθ)=L(1-cos(arcsin(d/L)));

则可得到所述靶标固定工装的速度v：(3) According to the law of conservation of mechanical energy, only when the gravitational force (or spring force) does work, the gravitational potential energy (or elastic potential energy) and kinetic energy of an object can be transformed into each other, but the total mechanical energy remains unchanged, that is

Then the speed v of the target fixing tool can be obtained:

(4) According to the momentum theorem, the momentum change of an object at the beginning and end of a process is equal to the impulse of the force it receives in this process, then the impulse I of the target sample in this direction:

Among them, g is the acceleration of gravity; m is the total mass of the target sample and the target fixture; L is the suspension height of the target fixture; d is the maximum swing amount of the target fixture in a certain direction.

By substituting the maximum swing dx of the target fixing tool in the x-axis direction into the above-mentioned impulse calculation formula, the impulse value Ix of the target sample in the x-axis direction can be obtained, namely

By substituting the maximum swing amount dy of the target fixing tool in the y-axis direction into the above impulse calculation formula, the impulse value Iy of the target sample in the y-axis direction can be obtained, namely

In this paper, specific examples are used to illustrate the principles and implementation methods of the present application, and the descriptions of the above embodiments are only used to help understand the methods and core ideas of the present application. The above is only a preferred embodiment of the present application. It should be pointed out that due to the limitation of literal expression, there are objectively unlimited specific structures. Under these circumstances, several improvements, modifications or changes can also be made, and the above-mentioned technical features can also be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the idea and technical solution of the invention can be directly applied to other occasions without improvement , should be regarded as the scope of protection of this application.

Claims (5)

1. A laser ablation drive irregular target two-dimensional impulse measurement device, characterized in that it includes: a laser emitting device (1) for emitting laser light, a focusing lens (2) for focusing laser light, and a laser beam for placing the target The target fixing tooling (3) of the sample, the suspension device for suspending the target fixing tooling (3), the first displacement measuring device (4) arranged along the axial direction of laser emission and the axial direction perpendicular to the laser emission The second displacement measuring device (5) that is set; The laser emitting device (1), the focusing lens (2) and the target fixing tool (3) are sequentially arranged laterally along the same horizontal line; the target fixing tool (3) can be produced by laser ablation of the target sample swing freely under the action of the impulse; the first displacement measuring device (4) and the second displacement measuring device (5) are located on the same horizontal plane, and the two are respectively used to measure the target fixing tooling in their respective directions. (3) the amount of swing; The target fixing tool (3) is a hollow cube structure; the target fixing tool (3) is provided with a placement port on the side facing the focusing lens (2); The suspension device includes a suspension bracket (6) and four suspension ropes (7) of equal length; the four suspension ropes (7) are respectively fixedly connected to the top four corners of the target fixing tool (3) , and the free ends of the four suspension ropes (7) are fixed at the same point on the suspension bracket (6). 2. The laser ablation-driven irregular target two-dimensional impulse measuring device according to claim 1, characterized in that, the outer surfaces of the three sides of the target fixing tool (3) that do not have the placement opening are respectively Smooth surface. 3. The laser ablation driven irregular target two-dimensional impulse measurement device according to claim 1, characterized in that, the first displacement measurement device (4) and the second displacement measurement device (5) are respectively laser Motion detector. 4. A laser ablation-driven irregular target two-dimensional impulse measurement method using the laser ablation-driven irregular target two-dimensional impulse measurement device according to any one of claims 1-3, characterized in that the method Include the following steps: Obtaining the maximum swing amount dx of the target fixing tool in the first direction and the maximum swing amount dy in the second direction by the first displacement measuring device and the second displacement measuring device; According to the maximum swing dx of the target fixing tool in the first direction, an impulse calculation algorithm is used to calculate the impulse value Ix of the target sample in the first direction; According to the maximum swing amount dy of the target fixing tool in the second direction, an impulse calculation algorithm is used to calculate the impulse value Iy of the target sample in the second direction. 5. The method for measuring the two-dimensional impulse of an irregular target driven by laser ablation according to claim 4, characterized in that, according to the maximum swing amount d of the target fixing tool in a certain direction, the impulse calculation algorithm is used to calculate the target sample at The methods of impulse value I in this direction include: Calculate the swing angle θ of the target fixing tool along this direction: θ = arcsin(d/L); Calculate the height change h of the target fixing tool in the vertical direction: h=L(1-cosθ)=L(1-cos(arcsin(d/L))); According to the law of conservation of mechanical energy, calculate the speed v of the fixed tooling of the target:

According to the momentum theorem, calculate the impulse I of the target sample in this direction:

Among them, g is the acceleration of gravity; m is the total mass of the target sample and the target fixture; L is the suspension height of the target fixture; d is the maximum swing amount of the target fixture in a certain direction.

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