CN104142739B - Laser point tracking system and method based on optical mouse sensing array - Google Patents

Abstract

The invention discloses a laser point tracking system based on an optical mouse sensor array, which includes a laser pointer, a projection light curtain, a computer, an optical mouse sensor array and a single-chip computer. position to expand the limited perception range of a single sensor, and the light curtain can convert laser points into laser speckles as trajectory tracking features; in addition, a laser point tracking method based on an optical mouse sensor array is also proposed. The method effectively fuses multiple sensing data in the sensing array to obtain the laser point trajectory. The algorithm is simple and has strong scalability, which is suitable for sensing arrays of different scales. The invention has low cost, is convenient to be installed in the projection system of the existing system, and is easy to operate to facilitate long-distance operation. At the same time, the system is not affected by the environment and projection light, and has strong stability.

Description

A laser point tracking system and method based on an optical mouse sensor array

technical field

The invention relates to the field of projection imaging, in particular to a laser point tracking system and method based on an optical mouse sensor array.

Background technique

At present, the projection system is very popular in teaching and working life. The projection system is an effective interactive demonstration method for multiple participants, but the human-computer interaction equipment (mouse and keyboard) used to control the projection system greatly limits the use The freedom of participants, who often have to walk from the participants back to the computer when human-computer interaction is required. Based on this, some new interactive devices for projection systems have been designed and used, mainly including three types: multifunctional projection laser pointers, wireless mice, and laser spot tracking devices based on machine vision. However, the above-mentioned technologies all have their own specific limitations when used for projecting interactive scenes.

First of all, the most commonly used type of projection system is the multi-functional laser pointer. This device adds a function button for turning pages of presentations to the traditional laser pointer, so that users of the projection system can present their own documents without using the mouse and keyboard. But an obvious problem is that the functions of such a device are very limited, and at the same time, it is impossible to control the cursor by moving it to complete more complex human-computer interaction operations on the projection interface like a mouse.

Secondly, the wireless mouse has also become a substitute for the wired mouse in recent years. The mouse, a traditional human-computer interaction device, is no longer limited by distance and can control the computer from a distance. However, the working characteristics of the mouse determine that it must stick to a working surface to measure its own movement to complete the control of the cursor. Such an operation is obviously extremely unnatural and inconvenient during projection presentations.

In addition, the method of tracking the position trajectory of the laser pointer light point based on machine vision uses the position of the light point in the image to estimate the actual position of the light point, and uses the position track of the light point instead of the mouse to measure its own position to operate the computer cursor. Alternative to the mouse. This method uses a camera to obtain images on the projection light curtain in real time, and uses digital image processing methods to extract and calculate the position of the laser point, but this method is easily affected by ambient light and lighting conditions of the projected image, and its stability is not high. At the same time, the algorithm complexity of image processing is high and the computing power is high, and there are high requirements for equipment, computing and their storage capabilities. At the same time, due to privacy considerations, its applicable occasions are limited.

Contents of the invention

The problem to be solved by the present invention is to provide a laser point tracking system and method based on an optical mouse sensor array to solve the problems of single function, inconvenient operation and low stability in the original projection device or method.

In order to solve the above problems, the present invention discloses a laser point tracking system based on an optical mouse sensor array, including a laser pointer, a projection light curtain and a computer, wherein it also includes an optical mouse sensor array and a single-chip microcomputer, wherein,

The optical mouse sensor array is arranged behind the projection light curtain, calculates and compares the laser speckle image formed by the laser point emitted by the laser pen on the sensor array surface through the scattering of the projection light curtain, and outputs The displacement information of the laser spot is given to the single-chip microcomputer;

The single-chip microcomputer judges the start and end of the laser spot track according to the received laser spot displacement information, and fuses and processes all the displacement information obtained by sensing to generate laser spot track information, and sends the track information to the computer;

The computer recognizes the laser point track information and simultaneously executes the projection program according to the track information.

Preferably, the projection light curtain and the sensor array of the optical mouse are arranged at a parallel interval, the interval distance is 400mm-600mm, and the best interval distance is 550mm, which has the best projection effect, and the optical mouse The size of the area covered by the array surface formed by the sensor array is preferably the same as the size of the projection light curtain.

Further, the optical mouse sensing array is arranged by optical mouse sensing chips arranged at equal intervals, and the optical mouse sensing array is at least set to 4, and the distance between two adjacent optical mouse sensing chips Set to the radius of the laser speckle model formed by laser point scattering times, assuming that the light spot formed by the scattering of the laser point on the sensing surface is modeled as a prototype of radius r, the sensor arrangement interval is This will cover the widest area.

Preferably, the optical mouse sensor chip is a chip without a light-through hole, that is to say, the light-through hole on the optical mouse sensor chip is removed to enhance the sensitivity of the chip to laser spot.

Preferably, the projection light curtain is made of double-sided rough translucent light-transmitting material, such as frosted plexiglass. The projected image produced by the projector can be diffusely reflected on the surface of the light curtain to present the projection. The light spot produced by the laser pointer has strong penetrability and can pass through the light curtain. After the laser passes through, it will be refracted, and interference will occur on the surface of the optical mouse sensor array, thereby forming laser speckle.

Further, the single-chip microcomputer wirelessly sends the laser point trajectory information to the computer through the Bluetooth serial port module. Of course, any other wireless transmission method such as ZigBee can also be used to send the data to the computer.

Based on another conception of the present invention, a kind of laser spot tracking method based on optical mouse sensor array is also provided, and this method comprises the following steps:

Step 1, sensor array deployment: measure the laser spot radius that enters through the laser pointer and passes through the projection light curtain to reach the sensor array surface that is spaced behind the light curtain, and adjust the optical mouse sensor in the sensor array. The spacing of the sensor chip, wherein the spacing is preferably adjusted to the laser spot radius In this way, a square tracking area without blind spots can be covered; the sensor array is placed parallel to the light curtain in advance, and separated by a certain distance d, and then a laser pointer is used to project a laser point on the light curtain, and the sensor array The laser spot radius r generated by measuring the plane where the array is located, and at the same time adjust the interval of the optical mouse sensor chip in the sensor array to Finally, the connection between the laser point tracker and the computer is established. There are at least 4 sensor chips arranged at equal intervals horizontally and vertically to form a rectangular shape.

Step 2. Acquisition of light spot trajectory: set the starting point of the light spot trajectory as (0,0), and at the same time select only one sensor chip at each moment to measure the increment of the light spot displacement, and calculate the position coordinates x _t , y _t ;

Step 3, judging the termination of the light spot track: whether the value of the register squal in the sensor array of the optical mouse is zero is used to determine whether the laser spot track is terminated.

Further, after calculating the position coordinates x _t and y _t of the light spot at time t, the spatial interpolation and smoothing processing are performed on the laser spot trajectory data;

Preferably, the position coordinate values x _t and y _t of the light spot at time t are calculated by adding the measured value of sensor i selected at time t to the position coordinate value of the light spot at time t-1, wherein, when using optical When the mouse senses the array, the displacement increment (Δxi _{, t} , Δy _{i, t} ) of the light spot is stored in the registers Delta_X and Delta_Y of each chip. The position of the light spot at time t can be calculated by the following formula:

Further, in the above formula, Δxi _{, t} and Δy _{i, t} are the measurements of sensor i selected at time t; the selection is based on the fact that the value S _{squal_i} of the SQUAL register of sensor i at this time is the maximum value in the sensor array of.

As another way to calculate the position coordinates of the light spot at time t, the weighted calculation is performed on the spot displacement increments detected by all the sensor chips in the sensor array at time t to obtain the weighted value, and the position coordinate value of the light spot at time t-1 Adding the weighted value at the t-th moment to calculate the position coordinate values x _t and y _t of the light spot at the t-time.

Wherein, the weighting method of the weighting operation is as follows:

Δx(y) _t = WD _t

Among them, the formulas W and D _t are calculated as follows:

D _t = [Δx(y) _{1, t} ... Δx(y) _{i, t} ... Δx(y) _{N, t} ] ^T ;

At this time, the position coordinate information of the laser point at each moment is:

Preferably, a cubic spline interpolation method is used to perform interpolation sampling at the position of the laser point at each moment.

More preferably, the laser point trajectory is smoothed by calculating the mean value of the trajectory points at adjacent moments, specifically:

Among them, x′ _t is the average displacement of abscissa at time t, and y′ _t is the average displacement of ordinate at time t.

In addition, the method for judging whether the track of the light spot has ended specifically includes the following steps:

Use a laser pointer to slide out a new gesture track;

Detect whether the Squal register values of all sensor chips are 0, and judge whether the laser point exists on the projection light curtain;

Set a threshold time through the timer, and judge whether the time that the Squal register value of the sensor chip is held at 0 reaches the set threshold time, to determine whether the track ends.

Further, when detecting that the Squal register values of all sensor chips are 0, set and start the timer, if not, re-detect;

When the Squal register value of the sensor chip is kept at 0 and reaches the time set by the timer, it means that the track ends and the timer is closed. If not, it is judged again whether there is a Squal register value of the sensor chip that is not 0, and retest to start the above steps.

Compared with the prior art, the laser point tracking system and tracking method based on the optical mouse sensor array provided by the present invention has lower cost, simple installation, convenient use, easy expansion, and can replace the traditional mouse human-machine The interactive system, without changing people's usage habits of the projection system, has more functions, is easy to operate and is conducive to long-distance operation. At the same time, the system is not affected by the external environment and its own projection light, and has strong stability. It is especially suitable for projection Long-distance human-computer interaction needs in the system.

Description of drawings

Fig. 1 is the structural representation of a kind of laser point tracking system based on optical mouse sensing array provided by the present invention;

Fig. 2 is the layout schematic diagram of optical mouse sensing array described in the embodiment of the present invention;

Fig. 3 (a) is a schematic diagram of the trajectory before smoothing according to the embodiment of the present invention;

Fig. 3 (b) is a schematic diagram of the trajectory after smoothing according to the embodiment of the present invention;

Fig. 4 is a schematic flow chart of the method for determining the start and end of the laser point track according to the present invention.

detailed description

The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention. Certain terms are used, for example, in the description and claims to refer to particular components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in name as the way to distinguish components, but use the difference in function of the components as the criterion for distinguishing. The subsequent description of the specification is a preferred implementation mode for implementing the present invention, but the description is for the purpose of illustrating the general principles of the present invention, and is not intended to limit the scope of the present invention. The scope of protection of the present invention should be defined by the appended claims.

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

The invention is based on the rapid detection ability of the optical flow algorithm firmware of the optical mouse chip on the movement of the image flow, combined with the tracking characteristics of the laser speckle image, and realizes a projection system oriented to projection interaction and laser point trajectory tracking. As shown in Figure 1, the tracking system based on the laser point trajectory described in the embodiment of the present invention includes an optical mouse sensor array 1, a projection light curtain 2, a single-chip microcomputer 3, a bluetooth serial port module 4, a laser pointer 5 and a computer, wherein The optical mouse sensor array 1 is composed of a plurality of optical mouse sensor chips 7 arranged horizontally and vertically at equal intervals. Here, only four are used as an example, and four are preferably used. Of course, it can also be set to 6, 8, or 9 The four optical mouse sensor chips 7 form a 2X2 sensor array, forming a square. The sensor array utilizes a plurality of optical mouse sensor chips to arrange and configure a single sensor chip. limited range of perception; the layout method of the optical mouse sensing array is as shown in Figure 2, and the light spot projected onto the plane where the sensing array is located is modeled as a circle of radius r, then the optical mouse sensor 7 The interval between can reach while forming a A square spot track perception and tracking area without blind spots; the projection light curtain 2 adopts the plexiglass commonly used in lamps, which is used as the receiving reflection surface of the projected image, and at the same time scatters the laser light spot, so that the laser light passes through the light curtain Generate laser speckle pattern 6, which can be captured by the sensor array and calculate the spot displacement. When installing the light curtain, it needs to leave a certain distance d from the plane of the sensor array. In order to obtain a better capture effect, the distance is between 400 and 600mm Can. The sensor array 1 and the projection light curtain 2 are placed in parallel and separated by a certain distance; the sensor chip uses the projection light curtain to calculate and compare the speckle image streams generated by laser point scattering, thereby outputting laser spot displacement information; The single-chip microcomputer 3 is used to judge the start and end of the laser point track, and fuses and processes all the displacement information obtained by sensing to generate the laser point track information; the bluetooth serial port module 4 is used to realize the wireless connection between the single-chip microcomputer and the computer, using This bluetooth serial port, as long as a USB bluetooth adapter is inserted on the PC side, it can communicate with many devices at the same time without affecting each other, and it is all wireless, keeping the desktop clean and tidy; the computer is used to identify the laser point track Interaction gestures are thereby understood, while regular projection procedures are performed through the projector.

The present invention also provides a laser point tracking method based on an optical mouse sensor array, which is also based on the projection interaction-oriented laser point track tracking system to track the track of the light point of the hand-held laser pointer in the projection system. The detailed steps are as follows:

Step 1. System installation and sensor array deployment

The frosted plexiglass light curtain is installed in front of the optical mouse sensor array plane to ensure that the light curtain is parallel to the sensor array plane and separated by a certain distance. The distance between the light curtain and the sensor array plane is preferably d=550mm. After that, project a laser point to the light curtain, measure the radius r of the laser spot scattered by the light curtain on the plane of the sensor array, and adjust the distance between the sensor chips in the sensor array to Finally, connect each module, supply power to the device, establish a connection between the laser point tracker and the computer, and adjust the projector to project the projected image onto the light curtain.

Step 2. Data fusion of sensor array and acquisition of light point trajectory

The trajectory of the laser point can be obtained by combining the spot displacement information detected by the sensor array at different times. Regarding the calculation of the position coordinates x _t and y _t of the light spot at time t, the present invention provides two methods for obtaining the track of the light spot by fusion sensor array measurement. The first method is the selection of the main sensor:

When using an optical mouse sensor array, the displacement increment of the light spot is stored in the registers Delta_X and Delta_Y of each chip. Assuming that the starting point of the spot track is (0,0), and at the same time, only one sensor chip is selected to measure the spot displacement increment at each moment. This special sensor is called the main sensor, and the position of the spot at time t can be used ( 1) Formula calculation:

Furthermore, in formula (1), Δxi _{, t} and Δy _{i, t} are the measurements of sensor i selected at time t; at this time, sensor i is the main sensor we choose, and the basis for selection is that sensor i is selected at this time The value S of the _SQUAL register of sensor i is the largest in the sensor array; and the value of the SQUAL register of the optical mouse sensor chip is an index used to measure the quality of the image stream obtained by the chip, when the value is higher , the higher the quality of the image stream captured by the sensor chip, the more accurate the displacement of the calculated image stream is, so the measurement of the main sensor in this method is the most accurate measurement at this moment; There is a certain error, but it is within a tolerable limit, and the computational complexity will not be increased due to the increase in the size of the sensor array, and it is suitable for the case of a large sensor array.

Another approach is sensory measurement weighted fusion:

Since the deployment method of the sensor makes the light spot not only captured and measured by one sensor in the array in a certain period of time, a more effective way to use the sensor measurement information is to combine all sensors in the sensor array at the tth time The spot displacement increment detected by the sensor chip is weighted, and the weighting method is as follows:

Δx(y) _t = WD _t (2)

in,

D _t = [Δx(y) _{1, t} ... Δx(y) _{i, t} ... Δx(y) _{N, t} ] ^T ;

At this time, the position of the laser point at each moment is calculated by formula (3):

The method of weighted fusion of sensory measurements utilizes more sensory measurement data, and the tracking of the spot trajectory is more accurate.

Step 3. Interpolation and smoothing of laser spot trajectory

Wherein, step 3 is mainly aimed at the situation that when the laser point track moves too fast, the sampling frequency reaches the limit and still cannot obtain enough track point data, the present invention adopts the method of cubic spline interpolation according to the position point obtained in (3) formula Interpolation generates more trajectory points. The biggest advantage of spline fitting is that it can fit more complex data with a lower order. The advantage of this is that it can avoid introducing unnecessary errors when using high-order polynomials. It can bring relatively good interpolation results, and at the same time, the calculation is faster. Since the cubic spline interpolation ensures the continuity of the slope and curvature of the point trajectory after interpolation, it conforms to the characteristics of human writing operation on laser points.

Furthermore, a method of using the mean value of the trajectory points at adjacent times to smooth the irregular trajectory caused by hand shaking when man controls the laser pointer is proposed, specifically:

The laser point trajectory and smooth trajectory obtained by using the method are shown in Figure 3(b). In the example, the operator wrote a number "3" with a laser pen. Compared with Figure 3(a) without smoothing, The smoothed ones are noticeably more accurate and visual.

This method proposes a method for effectively fusing multiple sensing data in the sensing array to obtain the laser point trajectory. The algorithm is simple and scalable, and is suitable for sensing arrays of different scales.

Step 4. Determine the start and end of the laser spot track

FIG. 4 is a schematic flowchart of a detailed flow chart of a method for determining the start and end of a laser pointer track based on the existence of a light spot.

When the device is used for human-computer interaction, it becomes an important issue to distinguish each independent laser point track. When the simulated human writes with a pen, after finishing writing a character, the pen tip will leave the paper and pause for a while. Correspondingly, when operating the laser point tracker, after the laser pointer completes a gesture trajectory, turn off the laser pointer and pause for a certain period of time. , preferably 2 seconds, then the laser point tracker can automatically determine that this part of the light point track ends, and when another light point track is captured, it will be automatically classified as a new track. Here, the value of the register SQUAL in the optical mouse sensor is used to determine whether to turn off the laser pointer. When there is no laser point on the light curtain, the values of all the sensing registers SQUAL in the array will be 0. If not, re-detect . When it is detected that the Squal register values of all sensor chips are 0, a timer is set to give a pause time.

Then judge whether the time set by the timer is reached, if it reaches the preset time, it means that the track is over, then turn off the timer, and then use the laser pointer to start a new track; if not, then judge again whether there is a certain The Squal register value of one or more sensor chips is not 0, if yes, then re-detect and start the above steps, if not, also re-detect and start the above steps. The present invention judges the existence of the laser point on the light curtain by using whether the value of the register SQUAL in the optical mouse sensor is zero, and combines the method of setting the threshold time to judge whether the track of a single laser point is terminated and whether a new track starts.

Compared with the single operation of the original pure mouse or laser pointer, the present invention is more convenient to use, and the function becomes more powerful, so that the traditional laser pointer has the function of writing, and is not disturbed by external light, and has strong stability.

It is worth noting that the above description is only a preferred embodiment of the present invention, and does not limit the scope of patent protection of the present invention. The present invention can also improve the materials and structures of the above-mentioned various components, or use technical equivalents are substituted. Therefore, all equivalent structural changes made by using the description and illustrations of the present invention, or directly or indirectly applied to other related technical fields are also included in the scope of the present invention.

Claims (12)

1. a laser spot tracking system based on optical mouse sensing array, comprising laser pointer, projection light curtain and computer, is characterized in that also comprising optical mouse sensing array and single-chip microcomputer, wherein, The optical mouse sensor array is arranged behind the projection light curtain, calculates and compares the laser speckle image formed by the laser point emitted by the laser pen on the sensor array surface through the scattering of the projection light curtain, and outputs The displacement information of the laser spot is given to the single-chip microcomputer; The single-chip microcomputer judges the start and end of the laser point track according to the received laser spot displacement information, and fuses and processes all the displacement information obtained by sensing to generate laser point track information, and wirelessly sends the track information to the computer through the Bluetooth serial port module; The computer recognizes laser point trajectory information and executes an interactive program according to the trajectory information; The projection light curtain and the optical mouse sensor array are arranged at a parallel interval, and the interval distance is 400 mm to 600 mm; The optical mouse sensor array is arranged by at least 4 optical mouse sensor chips arranged at equal intervals, and the distance between two adjacent optical mouse sensor chips is set to 100% of the radius of the laser speckle model formed by laser point scattering. times. 2. The laser point tracking system according to claim 1, wherein the optical mouse sensor chip is a chip without a small hole for light transmission. 3. The laser point tracking system according to claim 2, wherein the projection light curtain is made of double-sided rough translucent light-transmitting material. 4. A laser point tracking method based on optical mouse sensing array, is characterized in that the method comprises the steps: Step 1, sensor array deployment: measure the radius of the laser spot that enters through the laser pointer and passes through the projection light curtain to reach the sensor array surface behind the light curtain, and adjust the laser spot radius of each sensor array in the optical mouse sensor array. Sense chip spacing; Step 2. Acquisition of the laser point track: store the displacement increment of the spot in the register of the sensor chip, set the starting point of the spot track as (0,0), and select only one sensor chip at each time to measure the spot displacement , and calculate the position coordinates x _t and y t of the spot at time _t ; Step 3, judging the start and end of the laser point track: whether the value of the register squal in the optical mouse sensor array is zero is used to determine whether the laser point track is terminated. 5. laser point tracking method as claimed in claim 4, is characterized in that, the described sensing chip in described optical mouse sensing array is at least 4, and horizontally and vertically equally spaced arrangement, between adjacent sensing chips The distance between is adjusted to the laser spot radius times. 6. The laser point tracking method according to claim 5, wherein after calculating the position coordinates x _t and y _t of the light spot at time t, spatial interpolation and smoothing are performed on the laser light point track data. 7. The laser point tracking method as claimed in claim 4 or 6, characterized in that, the position coordinate values x _t and y _t of the light spot at the t moment are added by the position coordinate value of the light spot at the t-1 moment The measured value of the selected sensor i is calculated, wherein the selection basis is the S _squal value of the SQUAL register sensed at this moment, and the measurement of the sensor with the largest S _squal value in the sensing array is selected as the measured value. 8. The laser point tracking method as claimed in claim 4 or 6, characterized in that, the light spot displacement increments detected by all sensor chips in the sensor array at t time are carried out weighted calculation to obtain weighted value, by the light spot at t The position coordinate value at time -1 is added to the weighted value at time t to calculate the position coordinate values x _t and y t of the light spot at time _t . 9. laser point tracking method as claimed in claim 8, is characterized in that, the weighting method of described weighting operation is as follows: Δx(y) _t = WD _t in, $\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}}& \mathrm{<span\; class="notranslate">\; ...</span>}& \frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; N</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}}\end{array}\right]<span\; class="notranslate">\; ,</span>$ D _t = [Δx(y) _{1, t} ... Δx(y) _{i, t} ... Δx(y) _{N, t} ] ^T ; At this time, the position coordinate information of the laser point at each moment is: $\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}\end{array}\right.<span\; class="notranslate">\; .</span>$ 10. The laser point tracking method according to claim 6, wherein the spatial interpolation is to perform interpolation sampling by using a cubic spline interpolation method at each moment of the laser point. 11. The laser point tracking method as claimed in claim 6 or 9, wherein the smoothing process is performed on the laser point track by calculating the mean value of the track points at adjacent moments, specifically: $\left\{\begin{array}{c}{{\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}\\ {{\mathrm{<span\; class="notranslate">\; the\; y</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}\end{array}\right.$ Among them, x′ _t is the average displacement of abscissa at time t, and y′ _t is the average displacement of ordinate at time t. 12. The laser point tracking method according to claim 4, wherein the starting and ending of the laser point track comprises the following steps: Step S1, judge whether the laser point exists on the projection light curtain: check whether the Squal register values of all sensor chips are 0, if all 0, then set a threshold time by the timer, if not all 0, then retest; Step S2, judging whether the trajectory is over: judging whether the Squal register value of the sensor chip is held at 0 for a set threshold time, when the Squal register value of the sensor chip is held for 0 time reaches the time set by the timer , it indicates that the track ends, and the timer is closed. If not, it is judged again whether the Squal register value of the sensor chip is not 0, and the above steps are repeated for re-detection.