Steering control method of projector, projector and storage medium

Abstract

The invention discloses a steering control method of a projector, the projector and a storage medium, and the method comprises the following steps: obtaining a projection distance of the projector relative to a target projection surface and an attitude angle of the projector, and building a space coordinate system according to the projection distance and the attitude angle; obtaining a shooting picture, and identifying the indication light spot coordinates in the shooting picture; determining a target coordinate of the indication light spot coordinate in a space coordinate system according to a preset projection light path field angle, a projection distance, an attitude angle and a main transformation matrix between the shot picture and the original projection picture; calculating an adjusting angle of the projector according to a relative space relation between a reference point of a projection picture in the space coordinate system and the target coordinate; and indicating the projector to rotate to adjust the angle. According to the invention, the projector can automatically follow and rotate only by pointing the indicating light spot at the position to be projected, so that the projection picture is projected to the position of the corresponding indicating light spot.

Description

Technical Field

[0001] The present invention relates to the technical field of projection equipment, and in particular to a steering control method of a projector, a projector and a storage medium. Background Art

[0002] Projectors are used more and more widely, and their usage scenarios are becoming more and more diverse. When using a projector, a user may usually need to adjust the projection position of the projected image. This makes projection devices including brackets more popular, because by connecting the body of the projection device to the adjustable bracket, the projection position and angle of the projected image can be easily adjusted. However, in the prior art, when a user needs to adjust the projection position and angle of the projected image, usually only manual adjustment can be used to achieve the desired position or angle, which is very inconvenient to use. Summary of the invention

[0003] In order to solve the above technical problems, the present invention proposes a steering control method of a projector, a projector and a storage medium. By simply pointing the indicating light spot at the desired projection position, the projector can automatically follow the rotation and project the projection image to the corresponding position of the indicating light spot.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention discloses a steering control method for a projector, comprising the following steps:

[0006] Acquire a projection distance of the projector relative to a target projection surface and an attitude angle of the projector, and establish a spatial coordinate system according to the projection distance and the attitude angle;

[0007] Acquire a captured image and identify the coordinates of an indication light spot in the captured image;

[0008] Determine the target coordinates of the indicating light spot coordinates in the spatial coordinate system according to the preset projection light path field angle, the projection distance, the attitude angle, and the main conversion matrix between the captured image and the original projection image;

[0009] Calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture and the target coordinates in the spatial coordinate system;

[0010] The projector is instructed to rotate the adjustment angle.

[0011] Preferably, the acquiring of a captured image and identifying the coordinates of the indicating light spots in the captured image includes: acquiring an infrared captured image and identifying the coordinates of the indicating light spots in the infrared captured image; correspondingly, the main transformation matrix includes a preset first sub-transformation matrix and a second sub-transformation matrix, the first sub-transformation matrix includes a coordinate transformation relationship between the infrared captured image and the visible light captured image, the second sub-transformation matrix includes a coordinate transformation relationship between the visible light captured image and the projection original image, and the method for obtaining the second sub-transformation matrix includes: projecting a feature map onto a target projection surface and acquiring a visible light captured image, the visible light captured image including the feature map, and obtaining the second sub-transformation matrix based on the coordinate correspondence between the feature map in the projection original image and the visible light captured image.

[0012] Preferably, the method of acquiring a captured picture and identifying the coordinates of the indicating light spots in the captured picture includes: acquiring a visible light captured picture and identifying the coordinates of the indicating light spots in the visible light captured picture; correspondingly, the method of obtaining the main transformation matrix includes: projecting a feature map onto the target projection surface and acquiring a visible light captured picture, the visible light captured picture containing the feature map, and obtaining the main transformation matrix based on the coordinate correspondence between the feature map in the original projection image and the visible light captured picture.

[0013] Preferably, determining the target coordinates of the indicating light spot coordinates in the space coordinate system according to the preset projection light path field angle, the projection distance, the attitude angle, and the main conversion matrix between the captured image and the projection original image comprises:

[0014] Acquire the main conversion matrix between the captured image and the projection original image, and determine the mapping coordinates corresponding to the indicating light spot coordinates in the projection original image based on the operation of the indicating light spot coordinates and the main conversion matrix; determine the projection area corresponding to the projection image on the target projection surface in the spatial coordinate system according to the preset projection light path field angle, the projection distance, and the attitude angle; determine the relative position of the indicating light spot coordinates in the projection area according to the relative position of the mapping coordinates in the projection original image; and obtain the target coordinates of the indicating light spot coordinates in the spatial coordinate system according to the relative position of the indicating light spot coordinates in the projection area and the coordinates of the projection area in the spatial coordinate system.

[0015] Preferably, the calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture in the spatial coordinate system and the target coordinates comprises:

[0016] According to the relative spatial relationship between the reference point of the projection screen in the spatial coordinate system and the target coordinates, the adjustment angle of the projector when the reference point is moved to coincide with the target coordinates is calculated.

[0017] Preferably, the calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture in the spatial coordinate system and the target coordinates comprises:

[0018] Obtain a first vertical projection coordinate corresponding to a reference point of the projection screen in the spatial coordinate system in the vertical direction and a second vertical projection coordinate corresponding to the target coordinate in the vertical direction, wherein the first vertical coordinate and the second vertical coordinate are located on the same vertical line in the spatial coordinate system; determine an adjustment pitch angle of the projector according to a spatial relationship between the first vertical projection coordinate and the second vertical projection coordinate in the spatial coordinate system relative to the projector in the vertical direction.

[0019] Preferably, the attitude angle includes a vertical pitch angle, the projection optical path field angle includes a vertical field angle, and determining the adjusted pitch angle of the projector according to the spatial relationship between the first vertical projection coordinate and the second vertical projection coordinate in the spatial coordinate system relative to the projector in the vertical direction includes:

[0020] According to the projection distance, the attitude angle and the trigonometric calculation relationship, a first horizontal distance from the projector to the target projection surface in the spatial coordinate system is obtained; according to the height of the second vertical projection coordinate relative to the horizontal coordinate plane in the spatial coordinate system, the first horizontal distance, the vertical field of view angle and the trigonometric calculation relationship, a vertical target angle is obtained; based on the difference between the vertical target angle and the vertical pitch angle, an adjusted pitch angle of the projector is obtained.

[0021] Preferably, the calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture in the spatial coordinate system and the target coordinates comprises:

[0022] Obtain a first horizontal projection coordinate corresponding to a reference point of the projection screen in the spatial coordinate system in the horizontal direction and a second horizontal projection coordinate corresponding to the target coordinate in the horizontal direction, wherein the first horizontal projection coordinate and the second horizontal projection coordinate are located on the same horizontal plane in the spatial coordinate system; determine an adjusted yaw angle of the projector according to a spatial relationship between the first horizontal projection coordinate and the second horizontal projection coordinate relative to the projector in the horizontal direction in the spatial coordinate system.

[0023] Preferably, the attitude angle includes a horizontal tilt angle of the projector relative to the target projection surface, and determining the adjusted yaw angle of the projector according to a spatial relationship between the first horizontal projection coordinate and the second horizontal projection coordinate relative to the projector in the horizontal direction in the spatial coordinate system includes:

[0024] According to the projection distance, the attitude angle and the trigonometric calculation relationship, the second horizontal distance from the projector to the first horizontal projection coordinate in the spatial coordinate system is obtained; according to the horizontal inclination angle, the second horizontal distance and the trigonometric calculation relationship, the front projection corresponding coordinate on the target projection surface when the projector is facing the target projection surface is obtained; according to the distance between the projector and the front projection corresponding coordinate, the distance between the second horizontal projection coordinate and the front projection corresponding coordinate and the trigonometric calculation relationship, the horizontal target angle between the projector to the second horizontal projection coordinate and the front projection corresponding coordinate is obtained; according to the difference between the horizontal target angle and the horizontal inclination angle, the adjusted yaw angle of the projector is obtained.

[0025] In a second aspect, the present invention discloses a projector, comprising a processor and a memory, wherein the memory stores a computer program, and the computer program can be read and executed by the processor to implement the steering control method of the projector as described in the first aspect.

[0026] In a third aspect, the present invention discloses a storage medium storing a computer program, wherein the computer program is configured to be executable by a processor to execute the steering control method of the projector described in the first aspect.

[0027] Compared with the prior art, the beneficial effects of the present invention are: the steering control method of the projector, the projector and the storage medium proposed in the present invention, wherein the coordinates of the indicating light spot are obtained by acquiring the shooting picture, and the coordinates of the indicating light spot on the shooting picture are converted into the spatial coordinate system according to the field of view angle of the projection optical path, the projection distance, the attitude angle and the main conversion matrix, and then the adjustment angle of the projector is calculated according to the relative spatial relationship between the reference point of the projection picture and the target coordinates of the indicating light spot in the spatial coordinate system, and the projector is further instructed to rotate the corresponding adjustment angle, so that the user does not need to operate the electric pan-tilt head to control the steering, but only needs to emit the indicating light spot at the position where the projection is desired, and the electric pan-tilt head can automatically follow the rotation, so that the projection picture is projected to the corresponding pointing position, which is easy to use and improves the user experience.

[0028] In a further scheme, the steering control method of the projector of the present invention, wherein the calculation of the adjustment angle of the projector is divided into the calculation of the adjustment pitch angle and the adjustment yaw angle of the projector, and the adjustment pitch angle and the adjustment yaw angle are respectively calculated based on the projection coordinates of the reference point and the indicating light spot, the projection distance, the attitude angle and the trigonometric calculation relationship, and the obtained result is more accurate than the integral calculation method and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the hardware structure of the remote control;

[0030] Figure 2 It is a schematic diagram of the hardware structure of the projector;

[0031] Figure 3 It is a schematic diagram of the structure of the projector;

[0032] Figure 4 is a flow chart of a steering control method for a projector disclosed in Embodiment 1 of the present invention;

[0033] Figure 5 is a schematic diagram of a projection screen in a spatial coordinate system of a specific example of the present invention;

[0034] Figure 6 It is a schematic diagram for calculating the adjustment pitch angle of the projector;

[0035] Figure 7 It is a schematic diagram for calculating the adjustment yaw angle of the projector;

[0036] Figure 8 It is a schematic diagram of using the steering control method of the projector of the present invention to make the projection picture move along with the light spot. DETAILED DESCRIPTION

[0037] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0038] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for both fixing and circuit / signal communication.

[0039] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0041] The laser light source (infrared light or visible light) of the remote control will scatter a light spot (i.e., an indicator light spot) when it shines on the reflective surface (target projection surface such as the wall / curtain). The camera captures the position of the indicator light spot, calculates the position of the indicator light spot in the camera pixel coordinate system, and then calculates the position of the indicator light spot in the projection original image coordinate system through the corresponding conversion matrix. In addition, the electric pan-tilt projector has two automatic adjustments for horizontal yaw angle rotation and pitch angle rotation, and can be driven by an electric motor. Two electric motors can be configured in the projector, one for driving the projector to rotate on the horizontal plane, and the other for driving the projector to rotate on the vertical plane.

[0042] The preferred embodiment of the present invention discloses a steering control method for a projector. First, a laser is emitted by a laser to illuminate the projection screen of the projector. By identifying and calculating the spatial relative relationship of the reflected light spot (i.e., the indicating light spot) on the target projection surface with respect to the projector, the absolute coordinates of the indicating light spot on the projection screen can be accurately calculated. Then, the relative angle between the indicating light spot and the coordinates of the center point of the projection screen is calculated. The rotation amount of the electric pan-tilt head in the horizontal and pitch degrees of freedom can be controlled so that the center point of the projection screen coincides with the indicating light spot. Thus, the pan-tilt head can be controlled to rotate by remote control pointing so that the projection screen is projected to the position of the target projection surface desired by the user.

[0043] The hardware used in the projector steering control method disclosed in the preferred embodiment of the present invention includes: a remote controller and a projector, wherein the hardware structure diagram of the remote controller 10 is as shown in FIG. Figure 1 As shown, the hardware structure diagram of the projector 20 is as follows Figure 2 As shown, the structure of the projector 20 is as shown in Figure 3 shown.

[0044] The remote controller 10 mainly includes a laser 11, a power drive circuit 12, a Bluetooth remote control SOC (System on Chip) chip 13 and a first IMU (Inertial Measurement Unit) unit 14; wherein the power drive circuit 12 is used to drive the laser 11, and the laser 11 emits infrared light or visible light. The Bluetooth remote control SOC chip 13 can control the on and off of the laser 11 through the power drive circuit 12, as well as the on time length, that is, the pulse width of the on PWM waveform; the first IMU unit 14 is used to detect the position of the remote controller 10; the remote controller 10 can also establish a Bluetooth connection with the projector 20 through the Bluetooth remote control SOC chip 13.

[0045] The projector 20 mainly includes a first camera 21, a second camera 22, an optical machine 23, a SOC chip 24, a BT module 25, and a second IMU unit 26, wherein the first camera 21 is a visible light camera that can capture RGB three-color visible light images; the second camera 22 is an infrared camera with an infrared filter that can image infrared light of a specific band; the BT (BlueTooth) module 25 is used to establish a Bluetooth connection with the remote control 10, and is used for synchronous communication of the key value / voice data / status of the remote control; the second IMU unit 26 is used to detect changes in the pitch angle, rotation angle, and angular momentum of the projector 20, and is used for calculating the automatic trapezoidal / autofocus function of the projector 20 itself. Among them, the filter band of the second camera 22 can be a narrow band, which only passes infrared rays of a specific band, such as 980nm and 850nm; it can also be a broadband filter, which filters out the visible light band and retains the near-infrared band, such as filtering out visible light less than 780nm and retaining the infrared band above 780nm; when the laser 11 emits an infrared laser, the infrared light spot scattered by the infrared laser on the wall / curtain can be easily imaged by the infrared camera (second camera 22) on the projector 20, and the moving scattered infrared light spot can be compared by the previous and next two frames of images, and the trajectory of the infrared light spot can be identified.

[0046] It should be noted that, in some embodiments, the remote controller 10 may also emit a visible light spot through the laser 11 , and the projector may directly identify the position of the visible light spot through the visible light camera.

[0047] like Figure 3 As shown, it is a schematic diagram of the adjustment degree of the projector 20 including the electric pan-tilt head 201. The electric pan-tilt head 201 included in the projector 20 has two degrees of freedom adjustment of horizontal yaw angle rotation and pitch angle rotation, and is equipped with an electric motor to drive the projector 20 along the horizontal and pitch directions (not shown in the figure).

[0048] Before executing the steps of the projector steering control method, a main conversion matrix between the captured image and the original projection image is usually preset in the projector system. The original projection image is the image to be loaded and projected in the projector 20, and the size of the original projection image is generally 1920*1080.

[0049] Among them, when the laser 11 in the remote control 10 emits an infrared laser, the main conversion matrix at this time refers to the coordinate conversion relationship between the infrared shooting picture and the projection original picture. Further, the main conversion matrix includes a preset first sub-conversion matrix and a second sub-conversion matrix, the first sub-conversion matrix includes the coordinate conversion relationship between the infrared shooting picture and the visible light shooting picture, and the second sub-conversion matrix includes the coordinate conversion relationship between the visible light shooting picture and the projection original picture. The method for obtaining the second sub-conversion matrix includes: projecting a feature map onto the target projection surface, and obtaining a visible light shooting picture, the visible light shooting picture includes the feature map, and based on the coordinate correspondence between the feature map in the projection original picture and the visible light shooting picture, the second sub-conversion matrix is ​​obtained. The target projection surface is generally a wall or a curtain, and the feature map can be a common picture containing a chessboard, a QR code, etc. that is convenient for coordinate shooting and recognition.

[0050] When the laser 11 in the remote control 10 emits visible light laser, the main conversion matrix at this time refers to the coordinate conversion relationship between the visible light shooting picture and the projection original image. Furthermore, the method for obtaining the main conversion matrix includes: projecting a feature map onto the target projection surface, and obtaining a visible light shooting picture, the visible light shooting picture includes the feature map, and obtaining the main conversion matrix based on the coordinate correspondence between the feature map in the projection original image and the visible light shooting picture.

[0051] In a specific example, the first camera 21 in the projector 20 is a visible light camera, which is used for the autofocus and automatic trapezoidal functions of the projection; the second camera 22 is an infrared camera, which is used to capture the light spot scattered by the low-power infrared laser. In order to obtain the correspondence between the coordinates of the light spot recognized by the infrared camera and the coordinates of the original projection image, it is necessary to calibrate the external parameters of the infrared camera and the visible light camera in advance. In one calculation method, since the spatial parameters of the infrared camera and the visible light camera on the projector 20 are fixed and known, and the field of view angles of the two are also known parameters, a spatial coordinate system can be established based on these known hardware parameters. From the spatial coordinate system, the spatial relative position relationship between the shooting range of the infrared camera and the shooting range of the visible light camera can be determined, and in combination with the current projection distance, the first sub-conversion matrix H1 from the infrared camera screen coordinates to the visible light camera screen coordinates can be obtained.

[0052] In order to ensure the accuracy of spatial calculation, when the user moves the position or orientation of the projector, the projector can re-project a chessboard calibration map, identify the coordinates of the chessboard corner points after shooting with the visible light camera on the projector, and compare them with the coordinates of the original chessboard points in the original projection image, and update the coordinates of the visible light camera screen to the second sub-conversion matrix H2 of the original projection image coordinates. Assuming that the infrared camera recognizes that the coordinates of the infrared laser scattering spot in the infrared shooting screen are Z0, the coordinates of Z0 in the original projection image coordinate system are Z1=H2×H1×Z0; and if the laser in the remote control emits visible light, that is, the visible light calculation method is used for pan-tilt steering control, then the first sub-conversion matrix H1 is not needed, and Z1=H2×Z0 is satisfied at this time.

[0053] like Figure 4 As shown, Embodiment 1 of the present invention discloses a steering control method for a projector, comprising the following steps:

[0054] S1: Obtain the projection distance of the projector relative to the target projection surface and the attitude angle of the projector, and establish a spatial coordinate system according to the projection distance and the attitude angle;

[0055] like Figure 5 As shown, it is a schematic diagram of a projection screen in a spatial coordinate system of a specific example. In the established spatial coordinate system, O is the projection optical center in the projector 20; B is the center point of the lower edge of the current projection screen on the target projection surface 30; C is the center point of the lower edge of the projection screen on the target projection surface 30 when the simulated projector 20 is facing the wall (at this time, the pitch angle and the left and right tilt angles of the projector 20 are both 0); D is the center point of the lower edge of the projection screen when the simulated projector 20 is placed horizontally (at this time, the pitch angle of the projector is 0, but the left and right tilt angles are not necessarily 0); E is the center point of the upper edge of the current projection screen on the target projection surface 30; A0 is the center point of the current projection screen, A1 is the light spot formed on the target projection surface 30 when the remote control 10 points to it, that is, the indicator light spot; Av is the projection of A1 on the vertical plane at the center of the projection screen, and A H It is the projection of A1 on the horizontal plane where the projector 20 is located when the projector 20 is projecting forward. The OCD plane is the cross section between the lower edge of the screen and the target projection plane 30 when the projector 20 is placed horizontally.

[0056] ∠COD is the horizontal tilt angle of the projection, and ∠BOD is the vertical pitch angle of the projection. These two angles can be calculated by sensors related to the automatic trapezoidal correction of the projection. For example, the pitch angle ∠BOD is measured by a gyroscope (the second IMU unit 26), and the horizontal tilt angle ∠COD is measured by a TOF (Time offlight, time of flight) sensor. The projection distance OB can also be directly measured by the TOF sensor. Similarly, the BD and OD distances can be calculated by trigonometric relationship between OB and ∠BOD. ∠BOE is the vertical field of view of the projector optical machine, which is a known fixed value and is set to θ.

[0057] In this specific example, the projection distance of the projector 20 relative to the target projection surface 30 is OB, and the attitude angle of the projector 20 includes a vertical pitch angle ∠BOD and a horizontal tilt angle ∠COD.

[0058] S2: Acquire a captured image and identify the coordinates of an indication light spot in the captured image;

[0059] The camera that captures the captured image must be able to identify the light spot (i.e., the indicator light spot) emitted by the remote control so that its coordinates can be identified in the captured image. The identification method can be to set a narrow bandpass filter to filter out light other than the laser laser, so that only the corresponding laser light spot is left in the captured image; or it can also reduce the exposure so that only the laser light spot with a brightness much higher than the ambient light and the projection image brightness is left in the captured image.

[0060] In some embodiments, if the laser of the remote control emits an indicating light spot formed by infrared light, this step includes: acquiring an infrared shooting picture, and identifying the coordinates of the indicating light spot in the infrared shooting picture.

[0061] In other embodiments, if the laser of the remote control emits an indicating light spot formed by visible light, this step includes: acquiring a visible light shooting picture, and identifying the coordinates of the indicating light spot in the visible light shooting picture.

[0062] S3: Determine the target coordinates of the indicating light spot coordinates in the space coordinate system according to the preset projection light path field angle, projection distance, attitude angle, and the main conversion matrix between the captured image and the original projection image;

[0063] This step converts the indicating light spot of the laser identified in the shooting picture into a spatial coordinate system, so as to calculate the angle between the coordinates of the indicating light spot and the coordinates of the reference point in the projection picture in the spatial coordinate system.

[0064] Step S3 specifically includes:

[0065] S31: obtaining a main conversion matrix between the captured image and the original projection image, and determining the mapping coordinates corresponding to the coordinates of the indicator light spot in the original projection image based on the calculation of the coordinates of the indicator light spot and the main conversion matrix;

[0066] S32: Determine the projection area corresponding to the projection image on the target projection surface in the spatial coordinate system according to the preset projection light path field angle, projection distance, and attitude angle;

[0067] S33: Determine the relative position of the indicating light spot coordinates in the projection area according to the relative position of the mapping coordinates in the original projection image; and obtain the target coordinates of the indicating light spot coordinates in the spatial coordinate system according to the relative position of the indicating light spot coordinates in the projection area and the coordinates of the projection area in the spatial coordinate system.

[0068] exist Figure 5 In the example shown, the target coordinates of the coordinates of the indicating light spot in the shooting picture in the space coordinate system are the coordinates of A1. The relative coordinates of A1 in the shooting picture are identified by step S2, and the mapping coordinates of A1 in the projection original image coordinate system can be obtained by Z1=H2×H1×Z0. Among them, the projection original image coordinate system is a plane coordinate system, for example, a plane coordinate system with a corner point of the projection original image in the projection system as the origin, its length as the x-axis, and its height as the y-axis. After obtaining the mapping coordinates of A1 in the projection original image coordinate system, since the pixel length and width of the projection original image are known, for example, 1920*1080, and the length and width of the projection picture in the actual space can be calculated by the picture projection ratio (including the vertical field of view and horizontal field of view of the projection picture), the horizontal distance OD from the projector to the target projection surface, the vertical pitch angle and the horizontal tilt angle, wherein the picture projection ratio is known, the horizontal distance OD from the projector to the target projection surface can be calculated, and the vertical pitch angle and the horizontal tilt angle can be measured according to the sensor. In the spatial coordinate system O of the projector, the coordinates of the four vertices of the projected image can be calculated from the projection ratio of the image, the horizontal distance OD from the projector to the target projection surface, the vertical pitch angle, and the horizontal tilt angle. According to the relative position of A1 in the coordinate system of the original projection image, the corresponding target coordinates of A1 in the spatial coordinate system O can be obtained.

[0069] S4: Calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection image and the target coordinates in the spatial coordinate system;

[0070] Among them, this step includes: according to the relative spatial relationship between the reference point of the projection screen and the target coordinates in the spatial coordinate system, calculating the adjustment angle of the projector when the reference point is moved to coincide with the target coordinates. Furthermore, the reference point of the projection screen is the center point of the projection screen. In other implementations, the reference point can also be one of the four vertices of the projection screen, or the midpoint of a certain edge of the projection screen. Whether it is the center point, four vertices or the midpoint of the edge of the projection screen, after knowing the coordinates of the four vertices of the projection screen relative to the projector in the spatial coordinate system O, they can be easily calculated, and will not be repeated here.

[0071] The adjustment angles of the projector that need to be calculated include the adjustment angle of the vertical pitch angle (i.e., the adjustment pitch angle) and the adjustment angle of the horizontal tilt angle (i.e., the adjustment yaw angle). The following respectively calculates the adjustment pitch angle and the adjustment yaw angle of the projector according to different steps.

[0072] The step of calculating the adjustment pitch angle of the projector includes:

[0073] A1: Obtain a first vertical projection coordinate corresponding to a reference point of the projection screen in the spatial coordinate system in the vertical direction and a second vertical projection coordinate corresponding to the target coordinate in the vertical direction, wherein the first vertical coordinate and the second vertical coordinate are located on the same vertical line in the spatial coordinate system;

[0074] exist Figure 5 In the example shown, the reference point of the projection screen is the center point A0 of the projection screen, and the first vertical projection coordinate corresponding to A0 in the vertical direction is still A0; the target coordinate refers to the coordinate of A1 in the spatial coordinate system O, and the second vertical projection coordinate corresponding to the target coordinate in the vertical direction is the projection Av of A1 in the vertical direction; wherein A0 and Av are located on the same vertical line in the spatial coordinate system.

[0075] The adjusted pitch angle of the projector that needs to be calculated is the adjusted vertical pitch angle of the projector when the center point A0 of the projection screen moves to coincide with Av.

[0076] A2: Determine the adjustment pitch angle of the projector according to the spatial relationship between the first vertical projection coordinate and the second vertical projection coordinate in the vertical direction relative to the projector in the spatial coordinate system.

[0077] The attitude angle includes the vertical pitch angle ∠BOD, the projection optical path field angle includes the vertical field angle θ, and step A2 specifically includes:

[0078] A21: According to the projection distance OB, the vertical pitch angle ∠BOD and the trigonometric calculation relationship, the horizontal distance OD from the projector to the target projection surface in the spatial coordinate system is obtained;

[0079] like Figure 5 As shown, there is a trigonometric relationship According to the trigonometric calculation relationship, the horizontal distance OD from the projector to the target projection surface in the spatial coordinate system can be obtained, wherein the vertical pitch angle ∠BOD is determined by the pitch angle measured by the gyroscope, and the projection distance OB is measured by the TOF sensor.

[0080] A22: Obtain the vertical target angle ∠B'OD according to the height AvD of the second vertical projection coordinate relative to the horizontal coordinate plane in the spatial coordinate system, the horizontal distance OD, the vertical field angle θ and the trigonometric calculation relationship;

[0081] According to the target coordinates of A1 in the spatial coordinate system O obtained in step S3, the height of AvB can be obtained; at the same time, the height of BD can be calculated, so AvD = AvB + BD. H D can also be calculated based on the coordinates of A1 in the spatial coordinate system O.

[0082] Combination Figure 6 , assuming that the pitch angle of the projector has been adjusted, the projection screen A0 of the projector has overlapped with Av, and the center point of the upper edge of the projection screen moves to E', and the center point of the lower edge moves to B'. At this time, the following relationship exists:

[0083]

[0084] E′D=A V B′+A V E′+B′D=2A V B′+B′D=2(A V DB′D)+B′D=2A V DB′D

[0085] ∠E'OD=∠E'OB'+∠B'OD

[0086]

[0087] In the spatial coordinate system, for example, OD is set as the y-axis, then A V D is the length of the vertical axis of A1 coordinate, A H D is the horizontal axis length of the A1 coordinate.

[0088] Assume ∠B'OD=σ,B'D=a,A V D = b, OD = c, we can get the trigonometric equations, where ∠E'OB' = ∠EOB is the vertical field of view angle θ of the known optical machine, A V The height of D and the distance of OD are known. At this time, the above relationship is transformed into:

[0089]

[0090] in,

[0091] We can get:

[0092]

[0093] This is a complicated equation for tanσ, which can be approximated using a Taylor series expansion;

[0094] Among them, the Taylor expansion series of tanσ is:

[0095]

[0096] If the pitch angle is small, only the second-order term can be retained, that is, tanσ≈σ

[0097] The equation simplifies to linear equation of two variables.

[0098] Therefore, σ can be calculated based on the above two-variable linear equation, that is, the vertical target angle ∠B'OD can be obtained.

[0099] A23: Based on the difference between the vertical target angle and the pitch angle ∠BOD, the adjusted pitch angle of the projector is obtained.

[0100] Since ∠B'OD=σ, and the vertical pitch angle ∠BOD is also known, α=∠B'OD-∠BOD is the angle that needs to be adjusted to obtain the required vertical pitch angle, that is, the adjusted pitch angle of the projector.

[0101] The step of calculating the adjusted yaw angle of the projector includes:

[0102] B1: Obtain the first horizontal projection coordinates corresponding to the reference point of the projection screen in the spatial coordinate system in the horizontal direction and the second horizontal projection coordinates corresponding to the target coordinates in the horizontal direction, wherein the first horizontal projection coordinates and the second horizontal projection coordinates are located on the same horizontal plane in the spatial coordinate system;

[0103] exist Figure 5 In the example shown, the reference point of the projection screen is the center point A0 of the projection screen, and the first horizontal projection coordinate corresponding to A0 in the horizontal direction is D; the target coordinate refers to the coordinate of A1 in the spatial coordinate system O, and the second horizontal projection coordinate corresponding to the target coordinate in the horizontal direction is the projection A of A1 in the horizontal direction. H ; Among them, D and A H Located on the same vertical line in the spatial coordinate system.

[0104] The yaw angle of the projector to be calculated is to move the first horizontal projection coordinate D corresponding to the center point A0 of the projection screen in the horizontal direction to the position corresponding to A HAdjust the horizontal tilt angle of the projector when overlapping.

[0105] B2: Determine the adjustment yaw angle of the projector according to the spatial relationship between the first horizontal projection coordinate and the second horizontal projection coordinate in the spatial coordinate system relative to the projector in the horizontal direction.

[0106] Wherein, the attitude angle includes the horizontal inclination angle ∠COD of the projector relative to the target projection surface, and step B2 includes:

[0107] B21: According to the projection distance, attitude angle and trigonometric calculation relationship, the horizontal distance OD from the projector to the first horizontal projection coordinate in the spatial coordinate system is obtained;

[0108] B22: According to the horizontal tilt angle ∠COD, the horizontal distance OD and the trigonometric calculation relationship, the corresponding coordinate C of the orthographic projection on the target projection surface when the projector is facing the target projection surface is obtained;

[0109] Combination Figure 7 , ∠COD is the current horizontal tilt angle of the projector, which is a known quantity and can be measured by the TOF sensor. At this time, the following relationship exists:

[0110]

[0111] A H C=A H D+CD

[0112] Among them, A H First, the coordinates of A1 in the shooting image are converted by Z1=H2×H1×Z0 to obtain A H Coordinates in the projection original image coordinate system; A H D can be calculated based on the coordinates of A1 in the spatial coordinate system O.

[0113] OC is perpendicular to CD. The length of OC and CD can be calculated by ∠COD and OD through trigonometric function.

[0114] B23: According to the distance OC between the projector and the corresponding coordinates of the front projection, the distance A between the second horizontal projection coordinates and the corresponding coordinates of the front projection H C and trigonometric calculation relationship to obtain the horizontal target angle ∠COA between the projector to the second horizontal projection coordinate and the corresponding coordinate to the front projection H ;

[0115] like Figure 7 As shown, there is a trigonometric relationship According to the trigonometric calculation relationship, the horizontal target angle ∠COA between the projector to the second horizontal projection coordinate and the corresponding coordinate to the front projection can be obtained. H .

[0116] B24: According to the difference between the horizontal target angle and the horizontal tilt angle, the adjusted yaw angle of the projector is obtained.

[0117] β=∠COA H -∠COD is the angle that needs to be adjusted to obtain the required horizontal tilt angle, that is, the adjusted yaw angle of the projector.

[0118] S5: Instruct the projector to rotate and adjust the angle.

[0119] In this step, the electric pan-tilt platform of the projector is controlled to rotate at a horizontal angle of β and a vertical angle of α, so that the center point A0 of the projected image coincides with the position of the indicator light point A1.

[0120] When the indicator light spot A1 of the remote control keeps moving, the above steps are repeated continuously, so that the center point A0 of the projected image can keep approaching the moving indicator light spot A1 during the movement. Figure 8 As shown, in a specific example, in the initial state, the center point of the projection screen A is A0, and the infrared indicator light spot of the remote control points to the point A1 in the projection screen. In the control process of the steering control method of the projector disclosed in the first embodiment of the present invention, the movement direction of the remote control, the indicator light spot A1 moves to the point P1, the center point of the projection screen follows the indicator light spot to move to the point P0, and the coordinates of the center point of the projection screen are constantly approached to the coordinates of the indicator light spot, and finally the indicator light spot of the remote control points to the point Q1, and the center point of the projection screen also moves to the position of the point Q0, at which point Q1 overlaps with the position of the point Q0. During the entire movement process, the scattered light spot (i.e., the indicator light spot) of the infrared laser emitted by the remote control on the target projection surface 30 must always be within the shooting range of the infrared camera of the projector, otherwise the infrared camera on the projector may not easily capture the infrared light spot; or in some embodiments, the field of view of the infrared camera of the projector can also be set to be larger than the field of view of the projection optical machine.

[0121] In some embodiments, after the projector follows the rotation of the laser spot of the remote control, the system executes another round of steps S1 to S5 to re-identify whether the user has turned the remote control again and changed the position of the indicator light spot and the reference point. If there is a deviation between the reference point position and the indicator light spot position, the projector continues to rotate with the electric pan-tilt head according to the adjustment angle calculated in the new round of steps, so that the projector can follow the rotation of the laser spot of the remote control in real time.

[0122] Embodiment 2 of the present invention discloses a projector, including a processor and a memory, wherein a computer program is stored in the memory, and the computer program can be read and executed by the processor to implement the steering control method of the projector in embodiment 1.

[0123] The memory is a storage device that stores programs and data executed by the processor in a non-volatile manner. The memory is composed of semiconductor storage elements such as magnetic storage devices, flash read-only memories (ROM), or other types of non-volatile storage devices. The memory may also include random access memories (RAM) that constitute the working area of ​​the processor. The memory stores the control program executed by the processor. The processor may be composed of a single processor or a combination of multiple processing groups. The processor executes the control program to control various parts of the projection device.

[0124] Embodiment 3 of the present invention discloses a storage medium, in which a computer program is stored. The computer program is configured to be run by a processor to execute the steering control method of the projector in Embodiment 1.

[0125] Optionally, the storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0126] The background section of the present invention may contain background information about the problem or environment of the present invention, rather than describing the prior art by others. Therefore, the content contained in the background section is not an admission by the applicant that the prior art is available.

[0127] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of mutual contradiction, the technical personnel in this field can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope defined by the attached claims.

Claims

1. A method for controlling the steering of a projector, characterized in that: The following steps are involved: Acquire a projection distance of the projector relative to a target projection surface and an attitude angle of the projector, and establish a spatial coordinate system according to the projection distance and the attitude angle; Acquire a captured image and identify the coordinates of an indication light spot in the captured image; Determine the target coordinates of the indicating light spot coordinates in the spatial coordinate system according to the preset projection light path field angle, the projection distance, the attitude angle, and the main conversion matrix between the captured image and the original projection image; Calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture and the target coordinates in the spatial coordinate system; The projector is instructed to rotate the adjustment angle.

2. The method for controlling the steering of a projector according to claim 1, characterized in that: The acquiring of the captured image and identifying the coordinates of the indicating light spots in the captured image includes: acquiring an infrared captured image and identifying the coordinates of the indicating light spots in the infrared captured image; correspondingly, the main conversion matrix includes a preset first sub-conversion matrix and a second sub-conversion matrix, the first sub-conversion matrix includes a coordinate conversion relationship between the infrared captured image and the visible light captured image, the second sub-conversion matrix includes a coordinate conversion relationship between the visible light captured image and the projection original image, and the method for obtaining the second sub-conversion matrix includes: projecting a feature map onto a target projection surface and acquiring a visible light captured image, the visible light captured image including the feature map, and obtaining the second sub-conversion matrix based on the coordinate correspondence between the feature map in the projection original image and the visible light captured image; or, The method of acquiring a captured image and identifying the coordinates of the indicating light spots in the captured image includes: acquiring a visible light captured image and identifying the coordinates of the indicating light spots in the visible light captured image; correspondingly, the method of obtaining the main transformation matrix includes: projecting a feature map onto the target projection surface and acquiring a visible light captured image, wherein the visible light captured image includes the feature map, and obtaining the main transformation matrix based on the coordinate correspondence between the feature map in the original projection image and the visible light captured image.

3. The method for controlling the steering of a projector according to claim 1, characterized in that: Determining the target coordinates of the indicating light spot coordinates in the space coordinate system according to the preset projection light path field angle, the projection distance, the attitude angle, and the main conversion matrix between the captured image and the original projection image comprises: Acquire a main conversion matrix between the captured image and the original projection image, and determine the mapping coordinates corresponding to the coordinates of the indicator light spot in the original projection image based on the operation of the coordinates of the indicator light spot and the main conversion matrix; Determine the projection area corresponding to the projection image on the target projection surface in the spatial coordinate system according to the preset projection light path field angle, the projection distance, and the attitude angle; According to the relative position of the mapping coordinates in the original projection image, the relative position of the indicating light spot coordinates in the projection area is determined; and according to the relative position of the indicating light spot coordinates in the projection area and the coordinates of the projection area in the spatial coordinate system, the target coordinates of the indicating light spot coordinates in the spatial coordinate system are obtained.

4. The method for controlling the steering of a projector according to claim 1, characterized in that: The calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture in the spatial coordinate system and the target coordinates includes: According to the relative spatial relationship between the reference point of the projection screen in the spatial coordinate system and the target coordinates, the adjustment angle of the projector when the reference point is moved to coincide with the target coordinates is calculated.

5. The method for controlling the steering of a projector according to claim 4, characterized in that: The calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture in the spatial coordinate system and the target coordinates includes: Acquire a first vertical projection coordinate corresponding to a reference point of the projection screen in the spatial coordinate system in the vertical direction and a second vertical projection coordinate corresponding to the target coordinate in the vertical direction, wherein the first vertical coordinate and the second vertical coordinate are located on the same vertical line in the spatial coordinate system; The adjustment pitch angle of the projector is determined according to the spatial relationship between the first vertical projection coordinate and the second vertical projection coordinate in the spatial coordinate system relative to the projector in the vertical direction.

6. The method for controlling the steering of a projector according to claim 5, characterized in that: The attitude angle includes a vertical pitch angle, the projection optical path field angle includes a vertical field angle, and determining the adjusted pitch angle of the projector according to a spatial relationship between the first vertical projection coordinate and the second vertical projection coordinate in the spatial coordinate system relative to the projector in a vertical direction includes: According to the projection distance, the attitude angle and the trigonometric calculation relationship, a first horizontal distance from the projector to the target projection surface in the spatial coordinate system is obtained; Obtaining a vertical target angle according to the height of the second vertical projection coordinate relative to the horizontal coordinate plane in the spatial coordinate system, the first horizontal distance, the vertical field of view angle, and a trigonometric calculation relationship; Based on the difference between the vertical target angle and the vertical pitch angle, the adjusted pitch angle of the projector is obtained.

7. The method for controlling the steering of a projector according to claim 4, characterized in that: The calculating the adjustment angle of the projector according to the relative spatial relationship between the reference point of the projection picture in the spatial coordinate system and the target coordinates includes: Acquire a first horizontal projection coordinate corresponding to a reference point of the projection screen in the spatial coordinate system in the horizontal direction and a second horizontal projection coordinate corresponding to the target coordinate in the horizontal direction, wherein the first horizontal projection coordinate and the second horizontal projection coordinate are located on the same horizontal plane in the spatial coordinate system; An adjusted yaw angle of the projector is determined according to a spatial relationship between the first horizontal projection coordinate and the second horizontal projection coordinate relative to the projector in a horizontal direction in the spatial coordinate system.

8. The method for controlling the steering of a projector according to claim 7, characterized in that: The attitude angle includes a horizontal tilt angle of the projector relative to the target projection surface, and determining the adjusted yaw angle of the projector according to a spatial relationship between the first horizontal projection coordinate and the second horizontal projection coordinate relative to the projector in the horizontal direction in the spatial coordinate system includes: According to the projection distance, the attitude angle and the trigonometric calculation relationship, a second horizontal distance from the projector to the first horizontal projection coordinate in the spatial coordinate system is obtained; According to the horizontal tilt angle, the second horizontal distance and the trigonometric calculation relationship, obtaining the corresponding coordinates of the front projection on the target projection surface when the projector is facing the target projection surface; According to the distance between the projector and the coordinate corresponding to the front projection, the distance between the second horizontal projection coordinate and the coordinate corresponding to the front projection, and a trigonometric calculation relationship, a horizontal target angle between the projector and the second horizontal projection coordinate and the coordinate corresponding to the front projection is obtained; The adjusted yaw angle of the projector is obtained according to the difference between the horizontal target angle and the horizontal tilt angle.

9. A projector, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and the computer program can be read and executed by the processor to implement the steering control method of the projector as claimed in any one of claims 1 to 8.

10. A storage medium, characterized in that: The storage medium stores a computer program, wherein the computer program is configured to be executable by a processor to execute the steering control method for a projector as claimed in any one of claims 1 to 8.

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