Axle hole operation fine perception method based on visual tactile perception

Abstract

The invention relates to an axle hole operation fine sensing method based on visual tactile sensing, and belongs to the field of robot tactile sensing and planning. Comprising the following steps: extracting an optical flow image of the visual tactile sensor, and analyzing optical flow resultant vectors of all directions of the visual tactile sensor based on the optical flow image; the motion trend of the clamped object relative to the clamping jaw is obtained based on the optical flow resultant vector in each direction; based on the movement trend of the clamped object relative to the clamping jaw, the current relative direction of the shaft hole contact action point is obtained; the current shaft hole relative contact position is obtained based on the movement trend of the clamped object relative to the clamping jaw; and designing a closed-loop feedback controller to adjust the relative positions of the shaft holes until the relative positions are aligned based on the current relative directions of the shaft hole contact action points and the current relative contact positions of the shaft holes. According to the method, the problem that traditional visual positioning and sensing are blocked in fine operation and extreme environment tasks is solved, and the high-precision rapid shaft hole assembling method is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of robot tactile perception and planning, and in particular relates to a method for robot shaft hole assembly positioning perception and operation by comprehensively using tactile state information. Background Art

[0002] In the field of robot perception of the environment, it currently mainly relies on visual signals collected by various cameras for perception and analysis, so that the robot knows "where I am". For example, in the robot's material grasping task, the robot obtains image information of the task area through an RGB camera or RGB-D camera, extracts the outline of the object to be grasped, and further analyzes the position and posture of the object to be grasped, and finally controls the robotic arm to complete the grasping task. Although the application of robot visual inspection and servo in the industrial field is already very mature, the error of visual positioning is still too large when facing unstructured and uncalibrated scenes, making some delicate operation tasks difficult to complete. At this time, a new perception method is needed to further reduce the error range of perception.

[0003] In recent years, the perception technology of robots has been continuously developing, and the perception technology based on touch has gradually matured. Representative sensors include the GelSight and Gelslim series of the Massachusetts Institute of Technology, such as Figure 1 Although this tactile sensor still collects visual signals, it uses a colloidal material that can measure deformation, so it can more clearly measure the deformation of the sensor surface, thereby estimating a series of state parameters of the operation process. In addition, since the size of the sensor is small, the measurement accuracy is greatly improved.

[0004] Tactile sensors are naturally suitable for fine measurement tasks, can obtain accurate local information, and have great application prospects in fine operation tasks. Therefore, the present invention uses them in the fine operation task of shaft hole assembly. Summary of the invention

[0005] The technical problems to be solved by the present invention are:

[0006] In order to solve the problem that traditional visual positioning and perception are blocked in fine operations and extreme environment tasks, the present invention provides a fine perception method for shaft-hole operation based on visual-tactile perception, which uses tactile perception to perceive the relative position of the shaft hole to achieve faster shaft-hole assembly with higher precision.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A fine sensing method for shaft hole operation based on visual-tactile perception, characterized in that a two-finger gripper is used to grip an object for operation, and a visual-tactile sensor is installed at the end of each gripper; comprising:

[0009] Extracting an optical flow image of the visual-tactile sensor, and analyzing the optical flow resultant vectors in various directions of the visual-tactile sensor based on the optical flow image;

[0010] Obtaining the movement trend of the clamped object relative to the gripper based on the optical flow vectors in each direction;

[0011] Based on the movement trend of the clamped object relative to the clamping jaws, the current relative orientation of the shaft-hole contact point is obtained according to the relationship between the movement trend of the object and the orientation of the contact point when the bottom surface contacts;

[0012] Based on the movement trend of the clamped object relative to the clamping jaws, the current relative contact position of the shaft hole is obtained according to geometric reasoning;

[0013] Based on the current relative orientation of the shaft-hole contact action point and the current relative contact position of the shaft-hole, a closed-loop feedback controller is designed to adjust the relative position of the shaft-hole until it is aligned.

[0014] A further technical solution of the present invention is: extracting the optical flow image of the visual-tactile sensor, and analyzing the optical flow resultant vectors of the visual-tactile sensor in various directions based on the optical flow image, specifically:

[0015] When the clamping is stable, the RGB camera on the visual tactile sensor reads the current image of the flexible surface of the sensor in real time;

[0016] The optical flow method is used to process the received sensor flexible surface image and decompose the optical flow trend into each direction of the sensor coordinate system;

[0017] Calculate the optical flow vector in each direction of each visual-tactile sensor respectively.

[0018] A further technical solution of the present invention: The optical flow vectors in each direction include: X left , X right , Y left , Y right , curl left , curl right , where X left , X right , Y left , Y right , curl left , curl right are the resultant vectors of the optical flows along the X, Y and Z directions in the image coordinate systems of the left and right finger sensors, respectively.

[0019] A further technical solution of the present invention is: the motion trend of the clamped object relative to the clamping claw is obtained based on the optical flow vectors in each direction, specifically:

[0020]

[0021] Where r is the thickness at the clamping point; T(X), T(Y), T(Z), T(R z ) is the movement trend of the clamped object relative to the jaw in the jaw coordinate system, and both are dimensionless numbers.

[0022] A further technical solution of the present invention is as follows: based on the movement trend of the clamped object relative to the clamping jaws, the current relative orientation of the shaft hole contact point is obtained according to the relationship between the movement trend of the object and the orientation of the contact point when the bottom surface contacts, specifically:

[0023] T(X)=K1*ΔX, T(Y)=K2*ΔY, K1,K2>0

[0024] Among them, ΔX and ΔY are the distances that the contact point deviates from the coordinate origin in the gripper coordinate system. This formula shows that the movement trend of the clamped object is directly proportional to the coordinate distribution of the contact point, and <ΔX, ΔY> is the relative orientation of the contact point.

[0025] A further technical solution of the present invention is: based on the movement trend of the clamped object relative to the clamping jaws, the current relative contact position of the shaft hole is obtained according to geometric reasoning, specifically:

[0026]

[0027] in, <D x ,D y >The dimensional information of the contact surface relative to the contact point is obtained by measurement; <T(X) max ,T(Y) max >For size information <D x ,D y >The corresponding movement trend size;<T(X),T(Y)> is the size of the movement trend corresponding to the current contact position; <d x ,d y > is the calculated contact area position.

[0028] A further technical solution of the present invention: the closed-loop feedback controller is specifically:

[0029]

[0030] Among them, δX and δY are the adjustment amounts in the X and Y directions in the gripper coordinate system, P x and P y is the proportional coefficient for adjustment, which is determined by the following formula:

[0031]

[0032] Among them, αx and α y are the scale factors in the X and Y directions respectively.

[0033] A further technical solution of the present invention includes completing the shaft hole assembly operation based on the shaft hole alignment, specifically:

[0034] After alignment, twist downwards and insert. Check whether the insertion is complete according to the following formula:

[0035]

[0036] Among them, ε Z and is the motion trend threshold in the Z direction and Rz direction.

[0037] A computer system, characterized in that it comprises: one or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method.

[0038] A computer-readable storage medium, characterized in that it stores computer-executable instructions, which are used to implement the above method when executed.

[0039] The beneficial effects of the present invention are:

[0040] The present invention provides a method for fine perception of shaft-hole operation based on visual-tactile perception, which solves the problem of traditional visual positioning and perception being blocked in fine operations and extreme environment tasks, and realizes a method for rapid shaft-hole assembly with higher precision.

[0041] 1. Based on the object motion trend estimation of the two-finger gripper's tactile perception, a method is designed to estimate the motion trend of the object held by the gripper using the optical flow characteristics of the visual tactile sensor;

[0042] 2. Based on the tactile perception of the two-finger gripper, a method is designed to estimate the position of the external contact point according to the movement trend of the clamped object, and then estimate the relative position of the shaft hole;

[0043] 3. Design a closed-loop feedback controller based on the results of the relative position estimation of the shaft and hole to complete the alignment and assembly of the shaft and hole assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0045] Figure 1 GelSight and Gelslim series sensors.

[0046] Figure 2 Flowchart of the fine perception method for shaft-hole operation based on visual-tactile perception.

[0047] Figure 3 Description of the experimental coordinate system.

[0048] Figure 4 Axle-hole assembly experiment scene.

[0049] Figure 5 Optical flow diagram during operation.

[0050] Figure 6 Shaft-hole assembly experimental process data curve 1.

[0051] Figure 7 Shaft-hole assembly experimental process data curve 2.

[0052] Figure 8 Shaft-hole assembly experimental process data curve 3.

[0053] Fig. 9 Data curve 4 of the shaft-hole assembly experiment process. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0055] The present invention provides a fine perception and operation method for shaft hole assembly based on visual and tactile perception, which uses a two-finger gripper to clamp an object for operation, and a gelsight visual and tactile sensor is installed at the end of the gripper. The specific scene and coordinate system are defined as follows: Figure 3 and Figure 4 The specific steps include:

[0056] Step 1: Extract the optical flow image of the visual-tactile sensor and analyze the optical flow vector in each direction.

[0057] When the grip is stable, the RGB camera installed on the Gelsight sensor reads the current image of the flexible surface of the sensor in real time. Since the gripping object and the two-finger gripper have a relative motion tendency, the flexible surface of the Gelsight sensor will be deformed. The optical flow method is used to process the received image of the flexible surface of the sensor, and the optical flow tendency is decomposed into various directions of the sensor coordinate system, which can be decomposed into 6 directions: +X, -X, +Y, -Y, +Rz, -Rz. Among them, <+Rz, -Rz> is ​​the rotation tendency of the optical flow finger around the Z axis, which appears as a vortex in the image coordinate system. We choose to use the physical quantity of the curl to characterize the size of this vortex motion tendency. The resultant vector of the optical flow in each direction of the sensor on the left and right two-finger gripper is calculated respectively, and is defined as: X left , X right , Y left , Y right , curl left , curl right .

[0058] Step 2: Based on the sum vectors of the optical flows in all directions, the movement trend of the clamped object relative to the gripper is obtained.

[0059] In the gripper coordinate system, since the gripper stably holds one end of the object, the object's motion trend in any direction relative to the gripper can be decomposed into the following 8 independent motion directions: +X, -X, +Y, -Y, +Z, -Z, +Rz, -Rz, where <+Rz, -Rz> is ​​the rotation trend of the object finger around the Z axis. The motion trend of the two-finger optical flow and its combination can fully reflect the 8 motion trends of the gripper relative to the gripper. The motion trend of the gripper relative to the gripper satisfies the following quantitative analysis:

[0060]

[0061] Among them, X left , X right , Y left , Y right are the sum vectors of the optical flows in the X and Y directions in the image coordinate systems of the left and right finger sensors, respectively; r is the thickness of the clamping part; T(X), T(Y), T(Z), T(R z ) is the movement trend of the clamped object relative to the jaw in the jaw coordinate system, and both are dimensionless numbers.

[0062] Step 3: Based on the movement trend of the clamped object, the current relative position of the shaft-hole contact point is obtained according to the relationship between the movement trend of the object and the position of the contact point when the bottom surface contacts.

[0063] Since the contact occurs on the bottom surface of the clamped object, the motion trend and the contact point position satisfy the following relationship:

[0064] T(X)=K1*ΔX, T(Y)=K2*ΔY, K1,K2>0 (2)

[0065] Among them, ΔX and ΔY are the distances of the contact point from the origin of the coordinate system in the gripper coordinate system. This formula shows that the movement trend of the clamped object is directly proportional to the coordinate distribution of the contact point. <ΔX, ΔY> is the relative orientation of the contact point. The orientation of the contact point is defined as the positive and negative of ΔX and ΔY, which can be divided into four types: positive X direction, negative X direction, positive Y direction, and negative Y direction.

[0066] Step 4: Based on the relative orientation of the current shaft-hole contact point, the relative contact area position of the current shaft-hole is obtained according to geometric reasoning.

[0067] Based on the known geometry and size of the contact surface, the current shaft-hole contact position area position can be estimated by the relative orientation of the contact points:

[0068]

[0069] in, <D x ,D y >The dimensional information of the contact surface relative to the contact point is obtained by measurement; <T(X) max ,T(Y) max >For size information <D x ,D y >The corresponding movement trend size;<T(X),T(Y)> is the size of the movement trend corresponding to the current contact position; <d x ,d y > is the calculated contact area position.

[0070] Step 5: Based on the current relative contact position of the shaft and hole, a closed-loop feedback controller is designed to adjust the relative position of the shaft and hole until they are aligned.

[0071] The design of the closed-loop feedback controller is shown below:

[0072]

[0073] Among them, δX and δY are the adjustment amounts in the X and Y directions in the gripper coordinate system, P x and P y is the proportional coefficient for adjustment, which is determined by the following formula:

[0074]

[0075] Among them, α x and α y are the scale factors in the X and Y directions respectively.

[0076] After the controller is designed, repeat the first to fifth steps until the shaft holes are aligned relative to each other. When the shaft holes are aligned relative to each other, the following equation is satisfied:

[0077]

[0078] Among them, ε X and ε Y is the movement trend threshold in the X and Y directions. When the movement trends in the X and Y directions are both less than the threshold, it can be considered that the relative positions of the axis and the hole are aligned.

[0079] Step 6: Based on the alignment of the shaft holes, complete the shaft hole assembly operation.

[0080] After alignment, twist downwards and insert. Check whether the insertion is complete according to the following formula:

[0081]

[0082] Among them, ε Z and is the motion trend threshold in the Z direction and the Rz direction. This formula shows that if the shaft-hole assembly task is completed, the motion will be subject to greater constraints in the Z direction. At the same time, due to the contact between the shaft and the hole wall, the shaft will be subject to greater constraints in the direction of rotation around the Z axis.

[0083] In order to enable those skilled in the art to better understand the present invention, the present invention is described in detail below in conjunction with specific embodiments.

[0084] Embodiment 1:

[0085] In order to prove the effectiveness of the proposed method for fine perception and positioning of shaft hole operation based on visual tactile perception, we used Backyard two-finger gripper, gelsight visual tactile sensor, and shaft hole assembly task board to conduct actual operation verification. Figure 3 and Figure 4 shown.

[0086] Step 1: Extract the optical flow image of the visual-tactile sensor and analyze the optical flow vector in each direction.

[0087] When the clamping is stable, the RGB camera installed on the Gelsight sensor reads the current image of the flexible surface of the sensor in real time. Since the clamped object and the two-finger claw have a relative motion tendency, the flexible surface of the Gelsight sensor will be deformed. The optical flow method is used to process the received image of the flexible surface of the sensor, and the optical flow tendency is decomposed into various directions of the sensor coordinate system, which can be decomposed into 6 directions: +X, -X, +Y, -Y, +Rz, -Rz. Among them, <+Rz, -Rz> is ​​the rotation tendency of the optical flow finger around the Z axis, which appears as a vortex in the image coordinate system. We choose to use the physical quantity of the curl to characterize the size of this vortex motion tendency. The resultant vector of the optical flow in each direction of each sensor is calculated separately, defined as: X left , X right , Y left , Y right , curl left , curl right .

[0088] The schematic diagram of optical flow is as follows Figure 5 As shown, the calculation result of the resultant vector is automatically stored in the computer for subsequent use.

[0089] Step 2: Based on the sum vectors of the optical flows in all directions, the movement trend of the clamped object relative to the gripper is obtained.

[0090] In the gripper coordinate system, since the gripper stably holds one end of the object, the object's motion trend in any direction relative to the gripper can be decomposed into the following 8 independent motion directions: +X, -X, +Y, -Y, +Z, -Z, +Rz, -Rz, where <+Rz, -Rz> is ​​the rotation trend of the object finger around the Z axis. The motion trend of the two-finger optical flow and its combination can fully reflect the 8 motion trends of the gripper relative to the gripper. The motion trend of the gripper relative to the gripper satisfies the following quantitative analysis:

[0091]

[0092] Among them, X left , X right , Y left , Y right are the sum vectors of the optical flows in the X and Y directions in the image coordinate systems of the left and right finger sensors, respectively; r is the thickness of the clamping part; T(X), T(Y), T(Z), T(R z ) is the movement trend of the clamped object relative to the jaw in the jaw coordinate system, and both are dimensionless numbers.

[0093] The calculation results of the movement trend are stored in the computer.

[0094] Step 3: Based on the movement trend of the clamped object, the current relative position of the shaft-hole contact point is obtained according to the relationship between the movement trend of the object and the position of the contact point when the bottom surface contacts.

[0095] Since the contact occurs on the bottom surface of the clamped object, the motion trend and the contact point position satisfy the following relationship:

[0096] T(X)=K1*ΔX, T(Y)=K2*ΔY, K1,K2>0 (2)

[0097] Among them, ΔX and ΔY are the distances of the contact point from the origin of the coordinate system in the gripper coordinate system. This formula shows that the movement trend of the clamped object is directly proportional to the coordinate distribution of the contact point. <ΔX, ΔY> is the relative orientation of the contact point.

[0098] Step 4: Based on the relative orientation of the current shaft-hole contact point, the relative contact area position of the current shaft-hole is obtained according to geometric reasoning.

[0099] Based on the known geometry and size of the contact surface, the current shaft-hole contact position area position can be estimated by the relative position of the contact point:

[0100]

[0101] in, <D x ,D y >The dimensional information of the contact surface in the direction relative to the contact point is obtained by measurement; <T(X) max ,T(Y) max >For size information <D x ,D y >The corresponding movement trend size;<T(X),T(Y)> is the size of the movement trend corresponding to the current contact position; <d x ,d y > is the calculated contact area position.

[0102] In this case, D x =D y =15mm; T(x) max =0.95, T(y) max =0.048. Calculated <d x ,d y >Save to computer.

[0103] Step 5: Based on the current relative contact position of the shaft and hole, a closed-loop feedback controller is designed to adjust the relative position of the shaft and hole until they are aligned.

[0104] The design of the closed-loop feedback controller is shown below:

[0105]

[0106] Among them, δX and δY are the adjustment amounts in the X and Y directions in the gripper coordinate system, P x and P y is the proportional coefficient for adjustment, which is determined by the following formula:

[0107]

[0108] Among them, α x and α y are the proportional coefficients in the X and Y directions respectively. In this example, the present invention stipulates that α x =1.5,α y =80.

[0109] After the controller is designed, repeat the first to fifth steps until the shaft holes are aligned relative to each other. When the shaft holes are aligned relative to each other, the following equation is satisfied:

[0110]

[0111] Among them, ε X and ε Y is the movement trend threshold in the X and Y directions. When the movement trends in the X and Y directions are both less than the threshold, it can be considered that the relative positions of the axis and the hole are aligned.

[0112] In this example, the present invention sets ε X =0.1,ε Y =0.005. The present invention conducted 4 groups of experiments, such as Figures 6 to 9 As shown in the figure, the relative position alignment of the shaft and the hole was achieved after adjusting 2 to 4 times.

[0113] Step 6: Based on the alignment of the shaft holes, complete the shaft hole assembly operation.

[0114] After alignment, twist downwards and insert. Check whether the insertion is complete according to the following formula:

[0115]

[0116] Among them, ε Z and is the motion trend threshold in the Z direction and the Rz direction. This formula shows that if the shaft-hole assembly task is completed, the motion will be subject to greater constraints in the Z direction. At the same time, due to the contact between the shaft and the hole wall, the shaft will be subject to greater constraints in the direction of rotation around the Z axis.

[0117] In this example, the present invention sets ε Z =2, from Figures 6 to 9It can be seen that the final shaft-hole assembly meets the conditions for successful insertion, and the number of explorations required for successful insertion ranges from a minimum of 2 to a maximum of 4.

[0118] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A fine perception method for shaft hole operation based on visual and tactile perception, It is characterized in that The object is clamped by two-finger grippers for operation, and a visual tactile sensor is installed at the end of each gripper; including: Extracting an optical flow image of the visual-tactile sensor, and analyzing the optical flow resultant vectors in various directions of the visual-tactile sensor based on the optical flow image; Obtaining the movement trend of the clamped object relative to the gripper based on the optical flow vectors in each direction; Based on the movement trend of the clamped object relative to the clamping jaws, the current relative orientation of the shaft-hole contact point is obtained according to the relationship between the movement trend of the object and the orientation of the contact point when the bottom surface contacts; Based on the movement trend of the clamped object relative to the clamping jaws, the current relative contact position of the shaft hole is obtained according to geometric reasoning; Based on the current relative orientation of the shaft-hole contact action point and the current relative contact position of the shaft-hole, a closed-loop feedback controller is designed to adjust the relative position of the shaft-hole until it is aligned.

2. According to claim 1, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that The extracting of the optical flow image of the visual-tactile sensor and analyzing the optical flow resultant vectors in various directions of the visual-tactile sensor based on the optical flow image are specifically as follows: When the clamping is stable, the RGB camera on the visual tactile sensor reads the current image of the flexible surface of the sensor in real time; The optical flow method is used to process the received sensor flexible surface image and decompose the optical flow trend into each direction of the sensor coordinate system; Calculate the optical flow vector in each direction of each visual-tactile sensor respectively.

3. According to claim 2, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that The optical flow vectors in each direction include: left , X right , Y left , Y right , curl left , curl right , where X left , X right , Y left , Y right , curl left , curl right are the resultant vectors of the optical flows along the X, Y and Z directions in the image coordinate systems of the left and right finger sensors, respectively.

4. According to claim 3, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that The motion trend of the clamped object relative to the gripper is obtained based on the optical flow vectors in each direction, specifically: Where r is the thickness at the clamping point; T(X), T(Y), T(Z), T(R z ) is the movement trend of the clamped object relative to the jaw in the jaw coordinate system, and both are dimensionless numbers.

5. According to claim 4, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that Based on the movement trend of the clamped object relative to the clamping jaws, the current relative orientation of the shaft hole contact point is obtained according to the relationship between the movement trend of the object and the orientation of the contact point when the bottom surface contacts: T(X)=K 1 *ΔX,T(Y)=K 2 *ΔY,K 1 ,K 2 >0 Among them, ΔX and ΔY are the distances that the contact point deviates from the coordinate origin in the gripper coordinate system. This formula shows that the movement trend of the clamped object is directly proportional to the coordinate distribution of the contact point, and <ΔX, ΔY> is the relative orientation of the contact point.

6. According to claim 4, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that Based on the movement trend of the clamped object relative to the clamping jaws, the current relative contact position of the shaft hole is obtained according to geometric reasoning, specifically: in, <D x ,D y >The dimensional information of the contact surface relative to the contact point is obtained by measurement; <T(X) max ,T(Y) max >For size information <D x ,D y >The corresponding movement trend size;<T(X),T(Y)> is the size of the movement trend corresponding to the current contact position; <d x ,d y > is the calculated contact area position.

7. According to claim 6, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that The closed-loop feedback controller is specifically: Among them, δX and δY are the adjustment amounts in the X and Y directions in the gripper coordinate system, P x and P y is the proportional coefficient for adjustment, which is determined by the following formula: Among them, α x and α y are the scale factors in the X and Y directions respectively.

8. According to claim 1, a method for finely perceiving shaft hole operation based on visual and tactile perception, It is characterized in that It also includes completing the shaft hole assembly operation based on the shaft hole alignment, specifically: After alignment, twist downwards and insert. Check whether the insertion is complete according to the following formula: Among them, ε Z and is the motion trend threshold in the Z direction and Rz direction.

9. A computer system, Features include: One or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the method of claim 1.

10. A computer-readable storage medium, Features Computer executable instructions are stored, and when the instructions are executed, they are used to implement the method of claim 1.

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