Method and device for intelligently determining rib edge by ultrasonic robot

Abstract

The invention discloses a method and device for intelligently determining the edge of a rib by an ultrasonic robot, and the method comprises the steps: moving a probe at the tail end of a mechanical arm of the ultrasonic robot to an initial position, and recording the initial contact force and initial position of the probe and a human body in the vertical axis direction; a mechanical arm of the ultrasonic robot is controlled to press downwards, the contact force and the position after pressing of the probe are recorded, and the current rigidity value is calculated according to the initial contact force and the initial position; then whether the current rigidity value and the obtained previous rigidity value are larger than a preset rigidity threshold value or not is judged; the position condition of the current probe is determined according to the judgment result, the probe is moved to the next initial position according to a preset moving rule, and the downward pressing and rigidity value judgment process of the mechanical arm of the ultrasonic robot is executed again; and according to the obtained three-dimensional space position after upward and downward pressing and the current three-dimensional space position after downward pressing, the rib edge position is obtained through calculation. According to the method, accurate judgment of the rib edge position can be realized.

Description

Technical Field

[0001] The invention relates to a method and a device for intelligently determining rib edges by an ultrasonic robot. Background Art

[0002] When using an ultrasound robot to perform autonomous ultrasound scanning of the abdominal liver, since the liver is located below the ribs, the ultrasound robot needs to perform an oblique scan along the lower edge of the ribs to accurately obtain the image data of the liver. Therefore, the judgment of the position of the rib edge is crucial to the accuracy and completeness of the scan.

[0003] In the prior art, an external camera is usually used to identify the rib edge. The image of the human abdominal surface is obtained by the external camera, and the position of the rib edge is identified and determined using artificial intelligence and image processing algorithms, providing a reliable landmark for subsequent robot scanning path planning. Summary of the invention

[0004] In order to obtain a more accurate rib edge, an embodiment of the present invention provides a method and device for intelligently determining the rib edge using an ultrasonic robot.

[0005] In a first aspect, an embodiment of the present invention provides a method for intelligently determining rib edges using an ultrasonic robot, which may include:

[0006] Move the probe at the end of the ultrasonic robot mechanical arm to an initial starting position, and record the starting contact force and starting position of the probe and the human body in the vertical axis direction;

[0007] According to the preset downward contact force, the ultrasonic robot arm is controlled to press downward, and the contact force and the position after pressing down between the probe and the human body in the vertical axis direction, as well as the three-dimensional spatial position of the probe after pressing down are recorded, and the current stiffness value is calculated in combination with the initial contact force and the initial position;

[0008] Determining whether the current stiffness value is greater than a preset stiffness threshold;

[0009] If yes, determine whether the last stiffness value obtained is greater than a preset stiffness threshold value; if yes, move the probe to the next starting position according to the first movement rule, and re-execute the above-mentioned ultrasonic robot mechanical arm's downward pressure and stiffness value judgment process; if no, calculate the rib edge position according to the obtained three-dimensional spatial position after the last downward pressure and the three-dimensional spatial position after the current downward pressure;

[0010] Otherwise, determine whether the previous stiffness value is greater than the preset stiffness threshold. If so, calculate the rib edge position based on the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, move the probe to the next starting position according to the second movement rule, and re-execute the above-mentioned ultrasonic robot mechanical arm depression and stiffness value judgment process.

[0011] In one or some optional implementations of the embodiments of the present application, the ultrasonic robot mechanical arm is controlled to press downward according to the preset downward contact force, and the contact force and the position after pressing down between the probe and the human body in the vertical axis direction, as well as the three-dimensional spatial position of the probe after the current downward pressing are recorded, and the current stiffness value is calculated in combination with the initial contact force and the initial position, including:

[0012] The desired contact force between the probe and the human body is set as a preset downward contact force, the ultrasonic robot arm is controlled to press downward, and the contact force and position after pressing between the probe and the human body in the vertical axis direction, as well as the three-dimensional spatial position of the probe after the current pressing in the three-dimensional coordinate system are recorded;

[0013] According to the initial contact force, the contact force after pressing down, the initial position and the position after pressing down, the current stiffness value is calculated based on the following formula:

[0014]

[0015] In the formula, K t Indicates the current stiffness value, f zstart represents the initial contact force, f zend represents the contact force after pressing down, p zstart Indicates the starting position, p zend Indicates the position after pressing down.

[0016] In one or some optional implementations of the embodiment of the present application, moving the probe to the next starting position according to the first movement rule includes:

[0017] Determine the direction of displacement to be below the ribs;

[0018] Combined with the current stiffness value, the displacement is obtained based on the following formula:

[0019]

[0020] In the formula, Δp xtcp represents the displacement, ΔX3 is the third recommended adjustment value, ΔX4 is the fourth recommended adjustment value, K3 is the third stiffness threshold, K4 is the fourth stiffness threshold, K t is the current stiffness value;

[0021] The next starting position is obtained according to the displacement direction, displacement amount and the three-dimensional space position after the current downward pressure.

[0022] In one or some optional implementations of the embodiment of the present application, moving the probe to the next starting position according to the second movement rule includes:

[0023] Determine the displacement direction to be above the ribs;

[0024] Combined with the current stiffness value, the displacement is obtained based on the following formula:

[0025]

[0026] In the formula, Δp xtcp represents the displacement, ΔX1 is the first recommended adjustment value, ΔX2 is the second recommended adjustment value, K1 is the first stiffness threshold, K2 is the second stiffness threshold, K t is the current stiffness value;

[0027] The next starting position is obtained according to the displacement direction, displacement amount and the three-dimensional space position after the current downward pressure.

[0028] In one or some optional implementations of the embodiment of the present application, the step of calculating the rib edge position according to the acquired three-dimensional spatial position after the previous downward pressure and the three-dimensional spatial position after the current downward pressure includes:

[0029] The average of the three-dimensional spatial position after the previous downward pressure and the three-dimensional spatial position after the current downward pressure is calculated to obtain the rib edge position.

[0030] In one or some optional implementations of the embodiments of the present application, in the process of controlling the ultrasonic robot mechanical arm to press downward according to the preset downward pressing contact force, the process further includes:

[0031] If it is detected during the pressing process that the lateral force applied to the probe is greater than a preset threshold, the pressing is terminated and the human body stiffness value is set to a preset maximum stiffness value.

[0032] In one or some optional implementations of the embodiments of the present application, before moving the probe at the end of the ultrasonic robot mechanical arm to the initial starting position, the method further includes:

[0033] Obtaining an initial posture matrix of the probe;

[0034] Taking the vector representation of the initial posture matrix on the longitudinal axis as a reference vector in the vertical direction;

[0035] Taking the projection vector of the vertical reference vector on the horizontal plane as the horizontal plane projection vector;

[0036] Multiplying the vertical direction reference vector and the horizontal plane projection vector to obtain a vertical plane normal vector;

[0037] Multiplying the vertical plane normal vector and the vertical direction reference vector to obtain an intersection vector;

[0038] Based on the initial posture matrix and the intersection vector, a posture change amount is calculated;

[0039] Based on the posture change, the probe is adjusted to a vertical posture.

[0040] In one or some optional implementations of the embodiments of the present application, after the probe at the end of the ultrasonic robot mechanical arm is moved to the initial starting position, the method further includes:

[0041] The expected contact force between the probe and the human body is set as a preset starting contact force.

[0042] In a second aspect, an embodiment of the present invention provides a device for intelligently determining rib edges using an ultrasonic robot, which may include:

[0043] A probe preparation module is used to move the probe at the end of the ultrasonic robot mechanical arm to an initial starting position, and record the starting contact force and starting position of the probe and the human body in the vertical axis direction;

[0044] The probe pressing module is used to control the ultrasonic robot mechanical arm to press downward according to the preset pressing contact force, record the contact force and position after pressing between the probe and the human body in the vertical axis direction, and the three-dimensional spatial position of the probe after pressing, and calculate the current stiffness value in combination with the starting contact force and the starting position;

[0045] A first judging module, used to judge whether the current stiffness value is greater than a preset stiffness threshold;

[0046] The second judgment module, if the current stiffness value is greater than the preset stiffness threshold, judges whether the last stiffness value obtained is greater than the preset stiffness threshold, if so, moves the probe to the next starting position according to the first movement rule, and re-executes the above-mentioned ultrasonic robot mechanical arm's downward pressure and stiffness value judgment process, if not, calculates the rib edge position according to the obtained three-dimensional spatial position after the last downward pressure and the three-dimensional spatial position after the current downward pressure;

[0047] The third judgment module judges whether the previous stiffness value is greater than the preset stiffness threshold if the current stiffness value is not greater than the preset stiffness threshold. If so, the rib edge position is calculated according to the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, the probe is moved to the next starting position according to the second movement rule, and the above-mentioned ultrasonic robot mechanical arm depression and stiffness value judgment process is re-executed.

[0048] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the method for intelligently determining rib edges by an ultrasonic robot as described above.

[0049] In a fourth aspect, an embodiment of the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the method for intelligently determining rib edges by an ultrasonic robot as described above.

[0050] In a fifth aspect, an embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory, and when the processor executes the computer program, the method for intelligently determining rib edges by an ultrasonic robot as described above is implemented.

[0051] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0052] An embodiment of the present invention provides a method for intelligently determining the rib edge by an ultrasonic robot. The method uses an ultrasonic robot to manipulate the probe at the end of the robotic arm to press down near the human ribs, record the contact force and position before and after the pressing, calculate the current stiffness value, and combine it with the previous stiffness value obtained during the last pressing to determine whether the current position of the probe is the rib edge. If not, determine the next starting position for pressing down, re-execute the pressing and judgment operations until the rib edge is determined. Compared with the traditional recognition method that relies on an external camera, this method is not affected by light and environmental conditions, can overcome external interference, and can achieve accurate judgment of the rib edge position only by calculating the stiffness change during the contact between the probe and the human body, significantly improving the image quality of the rib edge scan, so that subsequent oblique scanning such as the abdominal liver can obtain a more complete image.

[0053] At the same time, the traditional external camera may involve the collection of patient surface images when identifying the rib edge, which may pose a potential risk of infringing patient privacy. However, the present invention is based on the stiffness calculation of the contact between the end probe of the robotic arm and the human body, and completes the rib edge recognition completely through physical contact and internal calculation, effectively avoiding privacy issues.

[0054] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0055] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0057] Figure 1 A schematic diagram of the steps of a method for intelligently determining rib edges using an ultrasonic robot provided in an embodiment of the present invention;

[0058] Figure 2 A schematic diagram of a mechanical arm of an ultrasonic robot provided in an embodiment of the present invention;

[0059] Figure 3 A schematic diagram of the edge of a human rib provided by an embodiment of the present invention;

[0060] Figure 4 The probe provided for the embodiment of the present invention is located in the area above the rib edge;

[0061] Figure 5 The probe provided for the embodiment of the present invention is located in the area below the rib edge;

[0062] Figure 6 A schematic diagram of the structure of the device for intelligently determining rib edges by an ultrasonic robot provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0064] The inventors found that in the prior art, the prior art usually uses an external camera to identify the rib edge, but this method is greatly affected by ambient light and human body differences, and there is a risk of infringing patient privacy. Therefore, the shortcomings of the prior art in determining the rib edge directly affect the accuracy and efficiency of autonomous abdominal liver scanning, and a more automated and accurate solution is urgently needed. Based on this, the inventors made the present invention after further research and development, providing a method and device for intelligently determining the rib edge of an ultrasonic robot.

[0065] Embodiment 1

[0066] The first embodiment of the present invention provides a method for intelligently determining the rib edge by an ultrasonic robot, referring to Figure 1 As shown, the method may include the following steps S101-S105:

[0067] S101: Move the probe at the end of the ultrasonic robot arm to an initial starting position, and record the starting contact force and starting position between the probe and the human body in the vertical axis direction.

[0068] S102: According to the preset downward contact force, the ultrasonic robot arm is controlled to press downward, and the contact force and position after pressing down between the probe and the human body in the vertical axis direction, as well as the current three-dimensional spatial position of the probe after pressing down are recorded. Combined with the initial contact force and the initial position, the current stiffness value is calculated.

[0069] S103: Determine whether the current stiffness value is greater than a preset stiffness threshold: if so, execute step S104; if not, execute step S105.

[0070] S104: Determine whether the last stiffness value obtained is greater than the preset stiffness threshold. If so, move the probe to the next starting position according to the first movement rule, and re-execute the above-mentioned ultrasonic robot mechanical arm's downward pressure and stiffness value judgment process. If not, calculate the rib edge position based on the obtained three-dimensional spatial position after the last downward pressure and the current three-dimensional spatial position after downward pressure.

[0071] S105: Determine whether the previous stiffness value is greater than the preset stiffness threshold. If so, calculate the rib edge position based on the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, move the probe to the next starting position according to the second movement rule, and re-execute the above-mentioned ultrasonic robot mechanical arm depression and stiffness value judgment process.

[0072] An embodiment of the present invention provides a method for intelligently determining the rib edge by an ultrasonic robot. The method uses an ultrasonic robot to manipulate the probe at the end of the robotic arm to press down near the human ribs, record the contact force and position before and after the pressing, calculate the current stiffness value, and combine it with the previous stiffness value obtained during the last pressing to determine whether the current position of the probe is the rib edge. If not, determine the next starting position for pressing down, re-execute the pressing and judgment operations until the rib edge is determined. Compared with the traditional recognition method that relies on an external camera, this method is not affected by light and environmental conditions, can overcome external interference, and can achieve accurate judgment of the rib edge position only by calculating the stiffness change during the contact between the probe and the human body, significantly improving the image quality of the rib edge scan, so that subsequent oblique scanning such as the abdominal liver can obtain a more complete image.

[0073] At the same time, the traditional external camera to identify the rib edge may involve the collection of the patient's surface image, which has the potential risk of infringing the patient's privacy. However, the present invention is based on the stiffness calculation of the contact between the robot arm probe and the human body, and completes the rib edge recognition completely through physical contact and internal calculation, effectively avoiding privacy issues.

[0074] In the embodiment of the present application, the schematic diagram of the ultrasonic robot mechanical arm is as follows Figure 2 As shown, a probe is connected to the end of the robot arm. The XYZ at the probe is a schematic diagram of the direction of the tool coordinate system at the end of the robot arm. The XYZ axis of the robot arm base is a schematic diagram of the direction of the robot base coordinate system, which is used to indicate the three-dimensional spatial position of the probe at the end of the robot arm.

[0075] In the above step S101, the probe at the end of the ultrasonic robot arm is moved to the initial starting position, and the starting contact force and starting position of the probe and the human body in the vertical axis direction are recorded. Specifically, the following steps S1011-S1014 are included:

[0076] S1011: Adjust the probe to a vertical position.

[0077] Specifically, in order to ensure the accuracy of human body stiffness identification, the probe at the end of the ultrasonic robot arm is adjusted to a vertical state. The specific adjustment method includes the following steps S10111-S10117:

[0078] S10111: Obtain the initial posture matrix of the probe.

[0079] Specifically, the initial posture matrix R of the probe can be obtained. The posture matrix R is a 3×3 orthogonal matrix, and each column represents the tool coordinate system X of the end of the robot arm. t , Y t , Z tThe vector representation of the axis in the world coordinate system, where t represents the identifier of the tool coordinate system at the end of the robot arm. The expression of the posture matrix R is shown in the following formula 1:

[0080]

[0081] S10112: Take the vector representation of the initial posture matrix on the longitudinal axis as the vertical reference vector.

[0082] Specifically, it can be that the longitudinal axis Y is taken from the initial posture matrix R t The vector representation of the axis gives the vertical reference vector V ty =(R 01 ,R 11 ,R 21 ).

[0083] S10113: Take the projection vector of the vertical reference vector on the horizontal plane as the horizontal plane projection vector.

[0084] Specifically, it can be, take the vertical reference vector V ty The projection vector of the XY plane in the world coordinate system is used as the horizontal plane projection vector V txy =(R 01 ,R 11 ,0).

[0085] S10114: Multiply the vertical direction reference vector and the horizontal plane projection vector to obtain the vertical plane normal vector.

[0086] Specifically, the vertical direction reference vector and the horizontal plane projection vector may be multiplied to obtain the vertical plane normal vector based on the following formula 2:

[0087] V n =V ty ×V txy Formula 2

[0088] Where V n Represents the vertical plane normal vector, V ty Represents the vertical reference vector, V txy Represents the horizontal plane projection vector.

[0089] S10115: Multiply the vertical plane normal vector and the vertical direction reference vector to obtain the intersection vector.

[0090] Specifically, the vertical plane normal vector and the vertical direction reference vector are multiplied to calculate the tool coordinate system Y of the end of the robot arm: t The vertical plane of the axis and the tool coordinate system X t Z tThe intersection vector of the plane. As shown in the following formula 3:

[0091] V inter =V n ×V ty Formula 3

[0092] Where V inter represents the intersection vector, V n Represents the vertical plane normal vector, V ty Represents the vertical reference vector.

[0093] S10116: Based on the initial posture matrix and the intersection vector, the posture change is calculated.

[0094] Specifically, the intersection vector can be converted to the tool coordinate system at the end of the robot arm to obtain the local coordinate intersection vector. The calculation formula is shown in the following formula 4:

[0095] V tinter =R -1 ×V inter Formula 4

[0096] Where V tinter represents the intersection vector, R -1 represents the inverse matrix of the initial posture matrix, V inter Represents the intersection vector.

[0097] According to the local coordinate intersection vector, the probe needs to rotate around Y based on the following formula 5 t Angle of axis oscillation:

[0098]

[0099] In the formula, Δr y Indicates the posture angle that needs to be swung around the Yt axis, thereby determining the posture change amount as (0, Δr y , 0).

[0100] S10117: Based on the posture change, adjust the probe to a vertical posture.

[0101] The method of adjusting the probe posture based on the posture change amount is a prior art, and those skilled in the art can implement it according to the detailed description of the prior art, which will not be described in detail here.

[0102] S1012: Move the probe to the initial starting position.

[0103] In order to facilitate those skilled in the art to understand the present method, the initial starting position is described more clearly here, referring to Figure 3The schematic diagram of the human rib edge is shown, where the white line is a schematic rib edge, and the box area of ​​the two labeled probes is the value point of the initial starting position. When executing step S1012, any point near the rib edge can be selected as the initial starting position.

[0104] S1013: Setting the expected contact force between the probe and the human body as a preset starting contact force.

[0105] Specifically, after the posture and position adjustment of the probe is completed, the contact force between the probe and the human body needs to be adjusted to facilitate subsequent stiffness identification. The expected contact force between the probe and the human body is set as the preset starting contact force f d0 , f d0 It is a small force value in Newton (N). For example, the preset initial contact force can be set to 2N.

[0106] Next, under the control of the force control method, the contact force between the probe and the human body will be reduced to near the preset starting contact force. The force control method is a prior art and will not be described in detail here.

[0107] S1014: Record the initial contact force and initial position between the probe and the human body in the vertical axis direction.

[0108] Specifically, it can be that the recording probe and the human body are at Z t Initial contact force in the axial direction f zstart and the starting position p zstart .

[0109] It should be noted that although a preset initial contact force is set in step S1013, the contact force cannot be accurately controlled to the preset value during implementation, so the accurate initial contact force needs to be re-acquired in step S1014.

[0110] In the above step S102, according to the preset downward contact force, the ultrasonic robot arm is controlled to press downward, and the contact force and position after pressing down between the probe and the human body in the vertical axis direction, as well as the current three-dimensional spatial position of the probe after pressing down are recorded, and the current stiffness value is calculated by combining the initial contact force and the initial position. Specifically, the following steps S1021-S1022 are included:

[0111] S1021: Setting the expected contact force between the probe and the human body as a preset downward contact force, controlling the ultrasonic robot arm to press downward, and recording the downward contact force and the downward position between the probe and the human body in the vertical axis direction, as well as the three-dimensional spatial position of the probe after the current downward pressure.

[0112] Specifically, the expected contact force between the probe and the human body may be set to a preset downward contact force f dmax , f dmaxIt is a large force value in Newton (N). For example, the preset push-down contact force can be set to 16N.

[0113] Under the control of the force control method, the probe at the end of the ultrasonic robot arm will be pressed down until the contact force reaches the preset downward contact force, and the distance between the probe and the human body on the vertical axis Z is recorded. t The contact force f after pressing down in the direction zend and the position after pressing down p zend , and the three-dimensional spatial position p of the probe after it is pressed down t .

[0114] In the embodiment of the present application, it should also be noted that if the lateral force f on the probe is detected during the pressing process, xy Greater than the preset threshold f xy0 , it means that the probe is pressing down against the edge of the ribs. In order to avoid discomfort to the human body, the current downward pressure stage needs to be ended immediately and the human body stiffness value is set to the preset maximum stiffness value K. max , in Newton / meter (N / m). The preset threshold value f xy0 Can be set to 12N, preset maximum stiffness value K max Can be set to 3000N / m.

[0115] S1022: According to the initial contact force, the contact force after pressing down, the initial position and the position after pressing down, the current stiffness value is calculated based on the following formula 6:

[0116]

[0117] In the formula, K t Indicates the current stiffness value, f zstart represents the initial contact force, f zend represents the contact force after pressing down, p zstart Indicates the starting position, p zend Indicates the position after pressing down.

[0118] Among them, the larger the current stiffness value is, the harder the current human body area is, and the smaller the value is, the softer the current human body area is.

[0119] In the above step S103, it is determined whether the current stiffness value is greater than a preset stiffness threshold value: if so, step S104 is executed; if not, step S105 is executed.

[0120] Specifically, it can be determined according to the current stiffness value which area of ​​the human body is currently located, and by setting a preset stiffness threshold, it can be determined whether the current stiffness value is greater than the preset stiffness threshold: if so, it means that the current human body area is relatively hard, and the probe is located in the rib area, such as Figure 4As shown, step S104 needs to be executed at this time, and the subsequent operation is performed in combination with the data obtained in the previous pressing stage; if not, it means that the current human body area is relatively soft, and the probe is located in the area below the rib edge, such as Figure 5 As shown, at this time, step S105 needs to be executed, and subsequent operations are performed in combination with the data obtained in the previous pressing stage.

[0121] In the above step S104, it is determined whether the last stiffness value obtained is greater than the preset stiffness threshold. If so, the probe is moved to the next starting position according to the first movement rule, and the above ultrasonic robot mechanical arm's downward pressure and stiffness value determination process is re-executed. If not, the rib edge position is calculated based on the obtained three-dimensional spatial position after the last downward pressure and the current three-dimensional spatial position after downward pressure. Specifically, the following steps S1041-S1044 are included:

[0122] S1041: Obtain the last stiffness value obtained in the last pressing stage and the three-dimensional spatial position after the last pressing.

[0123] Specifically, if there is a previous pressing operation before the current pressing, the previous stiffness value obtained in the previous stage and the three-dimensional space position after the previous pressing are obtained. If there is no previous pressing operation, step S1043 is executed.

[0124] S1042: Determine whether the previous stiffness value is greater than a preset stiffness threshold: if so, execute step S1043; if not, execute step S1044.

[0125] Specifically, it can be to determine whether the last stiffness value is greater than the preset stiffness threshold: if so, it means that the position of the probe last time was the rib area. If the current probe is still in the rib area, it means that the rib edge is still in the area below the probe. At this time, it is necessary to control the probe to continue to move to the area below the rib to explore, execute step S1044, determine the next starting position, and re-execute the ultrasonic robot mechanical arm's downward pressure and stiffness value judgment process; if not, it means that the position of the probe last time was the area below the human rib edge. If the current probe is in the rib area, it means that the human rib edge is between the three-dimensional spatial position after the previous downward pressure and the three-dimensional spatial position after the current downward pressure, and execute step S1043 to obtain the rib edge.

[0126] S1043: Move the probe to the next starting position according to the first movement rule, and re-execute the process of pressing down and determining the stiffness value of the ultrasonic robot mechanical arm in steps S1013-S105.

[0127] The first movement rule specifically includes the following steps S10431-S10433:

[0128] S10431: Determine the direction of displacement to be below the ribs.

[0129] Specifically, it can be, refer to Figure 4 As shown in the figure, the current probe is located in the rib area and needs to be moved to the area below the rib, that is, the X direction shown in the figure, which represents the tool coordinate system X at the end of the robot arm. t axis.

[0130] Among them, the tool coordinate system Y of the robot end t The direction of the axis can be set according to the empirical value of the human rib direction, such as 35°-55°. Figure 4 Middle Y t The inclination angle of the axis is 45°.

[0131] S10432: Combined with the current stiffness value, the displacement is obtained based on the following formula 7.

[0132]

[0133] In the formula, Δp xtcp Represents the tool coordinate system X along the end of the robot arm t The displacement of the axis movement, ΔX3 is the third recommended adjustment value, ΔX4 is the fourth recommended adjustment value, K3 is the third stiffness threshold, K4 is the fourth stiffness threshold, K t is the current stiffness value.

[0134] In a specific embodiment, K3 is 1500 N / m, K4 is 3000 N / m, ΔX3 is 12 mm, and ΔX4 is 8 mm.

[0135] In the embodiment of the present application, a piecewise function is set by the current stiffness value to determine the displacement of the probe. That is, when the current stiffness value is relatively large, it means that the probe is still relatively far away from the edge of the rib. At this time, the moving distance can be appropriately increased to improve the efficiency of exploration. When the current stiffness is relatively small, it means that the probe is already relatively close to the edge of the rib. In this case, a smaller displacement is taken to reduce deviation and improve accuracy.

[0136] S10433: Obtain the next starting position according to the displacement direction, displacement amount and the three-dimensional spatial position after the current downward pressure.

[0137] Specifically, the probe obtained in step S10432 may be t The displacement in the axial direction determines the three-dimensional displacement of the probe as (Δp xtcp , 0, Δp ztcp ), Δp ztcp is the Z output by the force control algorithm t Then, the probe at the end of the robot arm is controlled to move from the current three-dimensional space position after pressing down to the next starting position.

[0138] S1044: Calculate a weighted mean value based on the acquired three-dimensional spatial position after the previous downward pressure and the three-dimensional spatial position after the current downward pressure to obtain the rib edge position, as shown in the following formula 8:

[0139] p rib =βp t-1 +(1-β)p t Formula 8

[0140] In the formula, p rib Indicates the position of the rib edge, p t-1 Indicates the three-dimensional spatial position after the upper and lower pressures, p t It represents the three-dimensional spatial position after the current downward pressure, and β represents the weighted ratio.

[0141] The weighted ratio β can be calculated by the following formula 9:

[0142]

[0143] In the formula, K t-1 Indicates the previous stiffness value, K t Indicates the current stiffness value, K0 is the preset stiffness value of the rib edge, which can be 1000N / m.

[0144] In the above step S105, it is determined whether the previous stiffness value is greater than the preset stiffness threshold. If so, the rib edge position is calculated based on the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, the probe is moved to the next starting position according to the second movement rule, and the above ultrasonic robot mechanical arm depression and stiffness value determination process is re-executed. Specifically, the following steps S1051-S1054 are included:

[0145] S1051: Obtain the last stiffness value obtained in the last pressing stage and the three-dimensional spatial position after the last pressing.

[0146] Specifically, if there is a previous pressing operation before the current pressing, the previous stiffness value obtained in the previous stage and the three-dimensional space position after the previous pressing are obtained. If there is no previous pressing operation, step S1054 is executed.

[0147] S1052: Determine whether the previous stiffness value is greater than a preset stiffness threshold: if so, execute step S1053; if not, execute step S1054.

[0148] Specifically, it can be to determine whether the previous stiffness value is greater than the preset stiffness threshold: if so, it means that the position of the probe in the previous downward pressure stage is the human rib area. If the current probe is located in the area below the rib edge, it means that the human rib edge is between the three-dimensional spatial position after the previous downward pressure and the three-dimensional spatial position after the current downward pressure, and step S1053 is executed to obtain the rib edge; if not, it means that the position of the probe in the previous downward pressure stage is the area below the rib edge, and the current probe is still located in the area below the rib edge, which means that the rib edge is still in the area above the probe. At this time, it is necessary to control the probe to continue to move to the area above the rib to explore, and step S1054 is executed to determine the next starting position, and the downward pressure and stiffness value judgment process of the ultrasonic robot mechanical arm is re-executed.

[0149] S1053: Calculate the average value based on the acquired 3D spatial position after the previous compression and the current 3D spatial position after the compression to obtain the rib edge position. The specific execution method is the same as the above step S1044, which will not be described in detail here.

[0150] S1054: Move the probe to the next starting position according to the second movement rule, and re-execute the process of determining the downward pressure and stiffness value of the ultrasonic robot mechanical arm in steps S1013-S105.

[0151] The second movement rule specifically includes the following steps S10541-S10543:

[0152] S10541: Determine the direction of displacement to be above the ribs.

[0153] Specifically, it can be, refer to Figure 5 As shown, the current probe is located in the area below the rib edge and needs to be moved to the area above the rib, that is, the opposite direction of the X direction shown in the figure.

[0154] S10542: Combined with the current stiffness value, the displacement is obtained based on the following formula 10.

[0155]

[0156] In the formula, Δp xtcp Represents the tool coordinate system X along the end of the robot arm t The displacement of the axis movement, ΔX1 is the first recommended adjustment value, ΔX2 is the second recommended adjustment value, K1 is the first stiffness threshold, K2 is the second stiffness threshold, K t is the current stiffness value.

[0157] In a specific embodiment, K1 is 1000 N / m, K2 is 1500 N / m, ΔX1 is -12 mm, and ΔX2 is -8 mm.

[0158] In the embodiment of the present application, a piecewise function is set by the current stiffness value to determine the displacement of the probe. That is, when the current stiffness value is relatively small, it means that the probe is still relatively far away from the edge of the rib. At this time, the moving distance can be appropriately increased to improve the efficiency of exploration. When the current stiffness is relatively small, it means that the probe is already relatively close to the edge of the rib. In this case, a smaller displacement is taken to reduce deviation and improve accuracy.

[0159] S10543: Obtain the next starting position according to the displacement direction, displacement amount and the current three-dimensional spatial position after pressing down.

[0160] Specifically, the probe obtained in step S10542 above may be t The displacement in the axial direction determines the three-dimensional displacement of the probe as (Δp xtcp , 0, Δp ztcp ), Δp ztcp is the Z output by the force control algorithm t Then, the probe at the end of the robot arm is controlled to move from the current three-dimensional space position after pressing down to the next starting position.

[0161] In the embodiment of the present application, a rib edge point in the entire rib edge curve can be determined through this method. Researchers in this field can redefine a new initial starting position after implementing this method, and the complete rib edge curve can be obtained after multiple executions.

[0162] Embodiment 2

[0163] Based on the same inventive concept, the embodiment of the present invention also provides a device for intelligently determining the rib edge of an ultrasonic robot, referring to Figure 6 As shown, the device comprises:

[0164] The probe preparation module 101 is used to move the probe at the end of the ultrasonic robot mechanical arm to an initial starting position, and record the starting contact force and starting position of the probe and the human body in the vertical axis direction;

[0165] The probe pressing module 102 is used to control the ultrasonic robot mechanical arm to press downward according to the preset pressing contact force, record the contact force and position after pressing between the probe and the human body in the vertical axis direction, and the three-dimensional spatial position of the probe after pressing, and calculate the current stiffness value in combination with the initial contact force and the initial position;

[0166] A first judging module 103 is used to judge whether the current stiffness value is greater than a preset stiffness threshold;

[0167] The second judgment module 104, if the current stiffness value is greater than the preset stiffness threshold, judges whether the last stiffness value obtained is greater than the preset stiffness threshold, if so, moves the probe to the next starting position according to the first movement rule, and re-executes the above-mentioned ultrasonic robot mechanical arm downward pressure and stiffness value judgment process, if not, calculates the rib edge position according to the obtained three-dimensional spatial position after the last downward pressure and the three-dimensional spatial position after the current downward pressure;

[0168] The third judgment module 105 determines whether the previous stiffness value is greater than the preset stiffness threshold if the current stiffness value is not greater than the preset stiffness threshold. If so, the rib edge position is calculated based on the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, the probe is moved to the next starting position according to the second movement rule, and the above-mentioned ultrasonic robot mechanical arm depression and stiffness value judgment process is re-executed.

[0169] Embodiment 3

[0170] Based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium having a computer program / instruction stored thereon. When the computer program / instruction is executed by a processor, the method for intelligently determining rib edges by an ultrasonic robot as described in the first embodiment above is implemented.

[0171] Embodiment 4

[0172] Based on the same inventive concept, an embodiment of the present invention further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the method for intelligently determining rib edges by an ultrasonic robot as described in the first embodiment above.

[0173] Embodiment 5

[0174] Based on the same inventive concept, an embodiment of the present invention further provides a computer device, including a memory, a processor, and a computer program stored in the memory. When the processor executes the computer program, the method for intelligently determining rib edges by an ultrasonic robot as described in the above embodiment 1 is implemented.

[0175] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0176] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0177] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0178] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0179] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for intelligently determining rib edges using an ultrasonic robot, characterized in that: include: Move the probe at the end of the ultrasonic robot mechanical arm to an initial starting position, and record the starting contact force and starting position of the probe and the human body in the vertical axis direction; According to the preset downward contact force, the ultrasonic robot arm is controlled to press downward, and the contact force and the position after pressing down between the probe and the human body in the vertical axis direction, as well as the three-dimensional spatial position of the probe after pressing down are recorded, and the current stiffness value is calculated in combination with the initial contact force and the initial position; Determining whether the current stiffness value is greater than a preset stiffness threshold; If yes, determine whether the last stiffness value obtained is greater than a preset stiffness threshold value; if yes, move the probe to the next starting position according to the first movement rule, and re-execute the above-mentioned ultrasonic robot mechanical arm's downward pressure and stiffness value judgment process; if no, calculate the rib edge position according to the obtained three-dimensional spatial position after the last downward pressure and the three-dimensional spatial position after the current downward pressure; Otherwise, determine whether the previous stiffness value is greater than the preset stiffness threshold. If so, calculate the rib edge position based on the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, move the probe to the next starting position according to the second movement rule, and re-execute the above-mentioned ultrasonic robot mechanical arm depression and stiffness value judgment process.

2. The method according to claim 1, characterized in that According to the preset downward contact force, the ultrasonic robot mechanical arm is controlled to press downward, the contact force and the position after pressing down between the probe and the human body in the vertical axis direction, and the three-dimensional spatial position of the probe after pressing down are recorded, and the current stiffness value is calculated in combination with the initial contact force and the initial position, including: The desired contact force between the probe and the human body is set as a preset downward contact force, the ultrasonic robot mechanical arm is controlled to press downward, and the contact force and position after pressing between the probe and the human body in the vertical axis direction, as well as the three-dimensional spatial position of the probe after the current downward pressing are recorded; According to the initial contact force, the contact force after pressing down, the initial position and the position after pressing down, the current stiffness value is calculated based on the following formula: In the formula, K t Indicates the current stiffness value, f zstart represents the initial contact force, f zend Indicates the contact force after pressing down, pzstar t Indicates the starting position, pzen d Indicates the position after pressing down.

3. The method according to claim 1, characterized in that The step of moving the probe to a next starting position according to a first movement rule comprises: Determine the direction of displacement to be below the ribs; Combined with the current stiffness value, the displacement is obtained based on the following formula: In the formula, Δp xtcp represents the displacement, ΔX3 is the third recommended adjustment value, ΔX4 is the fourth recommended adjustment value, K3 is the third stiffness threshold, K4 is the fourth stiffness threshold, K t is the current stiffness value; The next starting position is obtained according to the displacement direction, displacement amount and the three-dimensional space position after the current downward pressure.

4. The method according to claim 1, characterized in that: The step of moving the probe to a next starting position according to a second movement rule comprises: Determine the displacement direction to be above the ribs; Combined with the current stiffness value, the displacement is obtained based on the following formula: In the formula, Δp xtcp represents the displacement, ΔX1 is the first recommended adjustment value, ΔX2 is the second recommended adjustment value, K1 is the first stiffness threshold, K2 is the second stiffness threshold, K t is the current stiffness value; The next starting position is obtained according to the displacement direction, displacement amount and the three-dimensional space position after the current downward pressure.

5. The method according to claim 1, characterized in that The step of calculating the rib edge position according to the acquired three-dimensional spatial position after the previous downward pressure and the current three-dimensional spatial position after the downward pressure comprises: The weighted average of the three-dimensional spatial position after the previous downward pressure and the three-dimensional spatial position after the current downward pressure is calculated to obtain the rib edge position.

6. The method according to claim 1, characterized in that In the process of controlling the ultrasonic robot mechanical arm to press downward according to the preset downward pressing contact force, the process further includes: If it is detected during the pressing process that the lateral force applied to the probe is greater than a preset threshold, the pressing is terminated and the human body stiffness value is set to a preset maximum stiffness value.

7. The method according to claim 1, characterized in that Prior to moving the probe at the end of the ultrasound robot arm to an initial starting position, it also includes: Obtaining an initial posture matrix of the probe; Taking the vector representation of the initial posture matrix on the longitudinal axis as a reference vector in the vertical direction; Taking the projection vector of the vertical reference vector on the horizontal plane as the horizontal plane projection vector; Multiplying the vertical direction reference vector and the horizontal plane projection vector to obtain a vertical plane normal vector; Multiplying the vertical plane normal vector and the vertical direction reference vector to obtain an intersection vector; Based on the initial posture matrix and the intersection vector, a posture change amount is calculated; Based on the posture change, the probe is adjusted to a vertical posture.

8. The method according to claim 1, characterized in that After moving the probe at the end of the ultrasonic robot mechanical arm to the initial starting position, the method further includes: The expected contact force between the probe and the human body is set as a preset starting contact force.

9. An ultrasonic robot intelligently determines the rib edge device, characterized in that: include: A probe preparation module is used to move the probe at the end of the ultrasonic robot mechanical arm to an initial starting position, and record the starting contact force and starting position of the probe and the human body in the vertical axis direction; The probe pressing module is used to control the ultrasonic robot mechanical arm to press downward according to the preset pressing contact force, record the contact force and position after pressing between the probe and the human body in the vertical axis direction, and the three-dimensional spatial position of the probe after pressing, and calculate the current stiffness value in combination with the starting contact force and the starting position; A first judging module, used to judge whether the current stiffness value is greater than a preset stiffness threshold; The second judgment module, if the current stiffness value is greater than the preset stiffness threshold, judges whether the last stiffness value obtained is greater than the preset stiffness threshold, if so, moves the probe to the next starting position according to the first movement rule, and re-executes the above-mentioned ultrasonic robot mechanical arm's downward pressure and stiffness value judgment process, if not, calculates the rib edge position according to the obtained three-dimensional spatial position after the last downward pressure and the three-dimensional spatial position after the current downward pressure; The third judgment module judges whether the previous stiffness value is greater than the preset stiffness threshold if the current stiffness value is not greater than the preset stiffness threshold. If so, the rib edge position is calculated according to the three-dimensional spatial position after the previous depression and the three-dimensional spatial position after the current depression. If not, the probe is moved to the next starting position according to the second movement rule, and the above-mentioned ultrasonic robot mechanical arm depression and stiffness value judgment process is re-executed.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the method for intelligently determining the rib edge by an ultrasonic robot as described in any one of claims 1-8 is implemented.

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