Ultrasonic Robot Scanning Control Method, Device, Equipment and Storage Medium

Abstract

The present invention discloses an ultrasonic robot scanning control method, device, equipment and storage medium. The method includes: in the low-damping mode, controlling the robotic arm to move towards the area to be scanned of the human body to contact the human body, and when the contact force reaches the target contact force, entering the high-precision mode; in the high-precision mode, acquiring the interaction force and spatial position at the end of the robotic arm in real time, calculating the target joint torque by combining the target contact force, and then controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque. The damping value in the low-damping mode is lower than the first preset damping value. By adaptively adjusting the robotic arm to the low-damping mode before controlling the ultrasonic robot to scan, the damping value of the robotic arm is reduced, the compliance is good, which is convenient for the operator to move. When performing scanning, the robotic arm is adaptively adjusted to the high-precision mode, the damping value of the robotic arm is increased, and stable ultrasonic imaging is maintained.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic robots, and in particular to an ultrasonic robot scanning control method, device, equipment and storage medium. Background Art

[0002] At present, robots are widely used in industrial production, medical treatment, family education, logistics, entertainment and other scenarios, and human-machine collaboration has become one of the key research directions for the development of robots. Medical ultrasound examination, as a radiation-free and low-cost medical imaging diagnostic technology, is widely used in robot-assisted surgery. The stability and safety of human-machine interaction during surgery are crucial. This invention proposes an adaptive impedance algorithm that can adaptively adjust the damping in real time according to the environment, and can achieve scanning behavior with constant contact force, follow the human body's breathing and other ups and downs in real time, and can also reduce the damping in the event of accidental touch, protect the operator and the patient, and reduce safety hazards.

[0003] During the process of robot ultrasonic scanning, there is physical contact between the ultrasonic probe and the human body, and interactive control of the robot is required. In the field of robot interactive control, it can be divided into direct force control and indirect force control, and indirect force control includes compliance control and impedance control. The compliance control methods include passive compliance and active compliance, and impedance control can be subdivided into impedance control and admittance control.

[0004] Impedance control is a method of achieving indirect force control by controlling the movement of the robot. Its ultimate goal is neither to directly control the movement of the robot nor to directly control the contact force between the robot and the outside world, but to control the dynamic relationship between the two.

[0005] Currently, most common damping control schemes have fixed parameters and cannot adaptively adjust parameters according to the environment to change stiffness and damping. Therefore, in the process of human-computer interaction, the degree of flexibility and intelligence is low. Summary of the invention

[0006] In view of this, the present application provides an ultrasonic robot scanning control method, device, equipment and storage medium to solve the problem that the existing ultrasonic robot cannot adaptively change stiffness and damping during scanning.

[0007] To solve the above technical problems, a technical solution adopted in this application is as follows: Provide an ultrasonic robot scanning control method, which includes: In the low-damping mode, control the robotic arm to move towards the area to be scanned on the human body to make contact with the human body, and when the contact force reaches the target contact force, enter the high-precision mode; In the high-precision mode, obtain the interaction force and spatial position at the end of the robotic arm in real time, calculate the target joint torque in combination with the target contact force, and then control the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque. The damping value in the low-damping mode is lower than the first preset damping value.

[0008] As a further improvement of this application, obtaining the interaction force and spatial position at the end of the robotic arm in real time, calculating the target joint torque in combination with the target contact force, and then controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque includes: Obtaining the interaction force, speed and spatial position at the end of the robotic arm in real time, calculating the target joint torque in combination with the target contact force, and then controlling the robotic arm to perform ultrasonic scanning along a specified trajectory according to the first preset damping value and the target joint torque.

[0009] As a further improvement of this application, the calculation formula of the target joint torque is expressed as:

[0010]

[0011]

[0012] x e =x d -x a ;

[0013] F froce =K P S F (F a -F d )+K I ∫S F (F a -F d )dt;

[0014]

[0015]

[0016] Among them, τ represents the target joint torque, F ext is the description of the environmental stress of the six-axis force sensor in the tool coordinate system in the base coordinate system or the workpiece coordinate system, x e is the difference between the actual pose x a and the desired pose x d , is the second derivative of x e , is the first derivative of x e , K is the diagonal matrix of stiffness coefficients, B is the diagonal matrix of damping coefficients, F froce represents the component in the force control direction, F a is the actual contact force, F d is the target contact force, K P and K I are the error term parameter and the integral term parameter of the PI controller respectively, S F represents the diagonal matrix,, M(q) represents the robot inertia matrix, represents the Coriolis force and the centrifugal force, g(q) represents the gravity moment, J T (q) represents the transpose of the robot Jacobian matrix, represents the joint space acceleration, represents the joint space velocity, q represents the joint space coordinate vector, represents the Cartesian space desired velocity, represents the Cartesian space desired acceleration, J(q) represents the robot Jacobian matrix, represents the inverse of the robot Jacobian matrix.

[0017] As a further improvement of the present application, after controlling the robotic arm to perform ultrasonic scanning along a specified trajectory according to the first preset damping value and the target joint torque, it further includes: determining whether the velocity of the end of the robotic arm exceeds a preset velocity critical value; when the velocity exceeds the preset velocity critical value, triggering a low damping mode and controlling the damping value of the robotic arm to decrease; when the velocity does not exceed the preset velocity critical value, maintaining the high-precision mode.

[0018] As a further improvement of the present application, in the low damping mode, the damping value of the robotic arm is calculated based on the initial impedance coefficient, the velocity of the end of the robotic arm, and the impedance coefficient decrease amplitude, and the damping value of the robotic arm is between the first preset damping value and the second preset damping value, where the first preset damping value is greater than the second preset damping value; in the high-precision mode, the damping value of the robotic arm is the first preset damping value.

[0019] As a further improvement of the present application, the calculation formula for the damping value of the robotic arm is expressed as:

[0020]

[0021] where represents the damping value of the robotic arm, represents the Cartesian space velocity, represents the velocity of the end of the robotic arm, a represents the initial impedance coefficient, b represents the impedance coefficient decrease amplitude, c represents the second preset damping value, B max represents the first preset damping value, where a + c > B max>c > 0, and represents a preset speed critical value.

[0022] As a further improvement of the present application, after controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, it further includes: when the robotic arm completes the ultrasonic scanning task, controlling the robotic arm to move away from the human body to a target position and maintaining the robotic arm in a high-precision mode.

[0023] To solve the above technical problems, another technical solution adopted by the present application is: to provide an ultrasonic robot scanning control device, which includes: a preparation module, configured to control the robotic arm to move towards the area to be scanned on the human body to contact the human body in a low-damping mode, and when the contact force reaches the target contact force, enter the high-precision mode; a scanning module, configured to, in the high-precision mode, acquire the interaction force and spatial position of the end of the robotic arm in real time, calculate the target joint torque by combining the target contact force, and then control the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, and the damping value in the low-damping mode is lower than the first preset damping value.

[0024] To solve the above technical problems, another technical solution adopted by the present application is: to provide a computer device, the computer device includes a processor and a memory coupled to the processor, and program instructions are stored in the memory, and when the program instructions are executed by the processor, the processor executes the steps of the ultrasonic robot scanning control method as described in any one of the above.

[0025] To solve the above technical problems, another technical solution adopted by the present application is: to provide a storage medium storing program instructions capable of implementing the ultrasonic robot scanning control method as described in any one of the above.

[0026] The beneficial effects of the present application are: The ultrasonic robot scanning control method of the present application switches the robotic arm of the ultrasonic robot to a low-damping mode before controlling the ultrasonic robot to perform scanning, so as to reduce the damping value of the robotic arm, making the robotic arm more compliant. The operator can drag the robotic arm with low damping, which is convenient for the operator to place the robotic arm directly above the area to be scanned on the human body, and then control the robotic arm to move towards the area to be scanned on the human body to contact the human body. When the contact force reaches the target contact force, enter the high-precision mode. And in the high-precision mode, the damping value of the robotic arm increases to maintain stable ultrasonic imaging. Moreover, the end of the robotic arm is controlled to perform the scanning task in real time according to the interaction force and spatial position of the end of the robotic arm, ensuring sufficient contact between the end of the robotic arm and the human body, and maintaining the contact force between the end of the robotic arm and the human body within the specified interaction force range, and can adaptively follow the undulating movement of the human body surface according to the breathing amplitude of the human body to ensure good ultrasonic imaging effect. Description of the Drawings

[0027] Figure 1 is a schematic flowchart of the ultrasonic robot scanning control method according to an embodiment of the present invention;

[0028] Figure 2 is an adaptive impedance damping change curve diagram of the ultrasonic robot scanning control method according to an embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of the functional modules of the ultrasonic robot scanning control device according to an embodiment of the present invention;

[0030] Figure 4 is a schematic structural diagram of a computer device according to an embodiment of the present invention;

[0031] Figure 5 is a schematic structural diagram of a storage medium according to an embodiment of the present invention. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0033] The terms "first", "second", and "third" in the present application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0034] References to "embodiments" in this specification mean that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0035] Figure 1 is a schematic flowchart of the ultrasonic robot scanning control method according to an embodiment of the present invention. It should be noted that if there are substantially the same results, the method of the present invention is not limited to Figure 1 the process sequence shown. As Figure 1 shown, the ultrasonic robot scanning control method includes the steps:

[0036] Step S101: In the low-damping mode, control the robotic arm to move towards the area to be scanned on the human body to contact the human body, and when the contact force reaches the target contact force, enter the high-precision mode.

[0037] It should be noted that the ultrasonic robot in this embodiment includes two working states: the low-damping mode and the high-precision mode. Among them, in the low-damping mode, the damping value of the robotic arm of the ultrasonic robot is relatively low, and the compliance of the robotic arm is high. The operator can drag the robotic arm with low damping and place the robotic arm directly above the area to be scanned on the human body. In this case, the operator can complete it with relatively low damping and a fast execution speed; in the high-precision mode, the damping value of the robotic arm of the ultrasonic robot is relatively high, and the stability of the robotic arm is good, so that when ultrasonic scanning and imaging, stable ultrasonic imaging can be maintained.

[0038] Specifically, when a scanning task needs to be performed, after switching the robotic arm to the low-damping mode, it is convenient for the operator to place the robotic arm directly above the area to be scanned on the human body, and then control the robotic arm to move towards the area to be scanned on the human body until it contacts the human body. After contact between the end of the robotic arm and the human body, extrusion occurs. By obtaining the contact force between the end of the robotic arm and the human body, when the contact force reaches the target contact force, control the robotic arm to switch to the high-precision mode.

[0039] Step S102: In the high-precision mode, real-time obtain the interaction force and spatial position of the end of the robotic arm, calculate the target joint torque in combination with the target contact force, and then control the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque. The damping value in the low-damping mode is lower than the first preset damping value.

[0040] Specifically, to assist the ultrasonic scanning process, ensure sufficient contact between the robotic arm and the human body, and maintain the contact force between the end of the robotic arm and the human body within the specified interaction force range, in this embodiment, in the high-precision mode, the interaction force generated between the end of the robotic arm and the human body and the spatial position of the end of the robotic arm are obtained in real time, and then the target joint torque is calculated by combining the preset target contact force. Then, according to the first preset damping value and the target joint torque, the robotic arm is controlled to perform ultrasonic scanning. By adjusting the joint torque in real time, the purpose of real-time controlling the contact force between the end of the robotic arm and the human body is achieved.

[0041] Among them, the first preset damping value is relatively high. When the damping value of the robotic arm reaches the first preset damping value, the compliance of the robotic arm is low and it is not easy to move, which can maintain stable ultrasonic imaging. The damping value in the low-damping mode needs to ensure that the robotic arm has good compliance. Therefore, the damping value in the low-damping mode is lower than the first preset damping value.

[0042] Furthermore, in some embodiments, a trajectory can also be specified for the robotic arm, and then the robotic arm is controlled to move along the specified trajectory to scan a relatively large target area. Therefore, the steps of obtaining the interaction force and spatial position of the end of the robotic arm in real time, calculating the target joint torque by combining the target contact force, and then controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque include:

[0043] Obtain the interaction force, speed and spatial position of the end of the robotic arm in real time, calculate the target joint torque by combining the target contact force, and then control the robotic arm to perform ultrasonic scanning along the specified trajectory according to the first preset damping value and the target joint torque.

[0044] Specifically, by obtaining the interaction force, speed and spatial position of the end of the robotic arm in real time, calculating the target joint torque by combining the target contact force, and finally controlling the robotic arm to perform ultrasonic scanning along the specified trajectory according to the first preset damping value and the target joint torque.

[0045] Furthermore, the calculation formula of the target joint torque is expressed as:

[0046]

[0047]

[0048] x e =x d -x a ;

[0049] F froce =K P S F (F a -F d )+KI ∫S F (F a -F d )dt;

[0050]

[0051]

[0052] where τ represents the target joint torque, and F ext is the description of the environmental stress of the six-axis force sensor in the tool coordinate system in the base coordinate system or the workpiece coordinate system. x e is the actual pose x a minus the desired pose x d . is the first derivative of x e . K is the stiffness coefficient diagonal matrix, B is the damping coefficient diagonal matrix, and K and B are positive definite matrices. F froce represents the component in the force control direction, F a is the actual contact force, F d is the target contact force, K P and K I are the error term parameter and the integral term parameter of the PI controller respectively. S F represents the diagonal matrix, M(q) represents the robot inertia matrix, represents the Coriolis force and the centrifugal force, g(q) represents the gravity moment, J T (q) represents the transpose of the robot Jacobian matrix, represents the joint space acceleration, represents the joint space velocity, q represents the joint space coordinate vector, represents the Cartesian space desired velocity, represents the Cartesian space desired acceleration, J(q) represents the robot Jacobian matrix, represents the inverse of the robot Jacobian matrix.

[0053] Specifically, the above calculation formula of this embodiment is constructed based on the original impedance model, the PI control algorithm, and the robot dynamics model. The original impedance model is:

[0054]

[0055] where, is the second derivative of x e . M is the inertia coefficient diagonal matrix, and M is a positive definite matrix.

[0056] In the scanning task, in order to make the robotic arm exhibit sufficient compliance, this embodiment defines the desired applied force F ext as:

[0057]

[0058] Among them, F force represents the component in the force control direction to ensure the contact between the ultrasonic probe and the human body and maintain the contact force at the set target contact force level. To achieve this function, the PI control algorithm is adopted in this embodiment, and the specific calculation formula is as follows:

[0059] F froce = K P S F (F a - F d ) + K I ∫S F (F a - F d )dt;

[0060] Among them, F a is the actual contact force, F d is the target contact force, K P and K I are the error term parameter and the integral term parameter of the PI controller respectively. Since force control is not required in the horizontal direction, a S F diagonal matrix is needed, and the value on the diagonal element related to the Z axis is set to 1, and the parameters related to the horizontal direction are set to 0.

[0061] The robot dynamics model is:

[0062]

[0063] Substituting the above data into the robot dynamics model, the expression of the joint torque τ can be obtained:

[0064]

[0065] In the case of a specified trajectory, the velocity and acceleration at the end of the robotic arm are expressed as:

[0066]

[0067]

[0068] After deformation, it can be obtained:

[0069]

[0070]

[0071] Therefore, when scanning a fixed area at the end of the robotic arm without the need to move, and The value is 0.

[0072] Through the above method, this embodiment can control the contact situation between the robotic arm and the human body in the vertical direction, which has a certain compensation effect on the human body's respiratory movement during the ultrasonic scanning process. It can adaptively follow the undulating movement of the human body surface according to the amplitude of human respiration and maintain a constant contact force.

[0073] Further, to improve the safety when using the device and prevent the robotic arm from accidentally injuring the human body during the scanning task, in some embodiments, after the step of controlling the robotic arm to perform ultrasonic scanning along a specified trajectory according to the first preset damping value and the target joint torque, the following steps are further included:

[0074] 1. Determine whether the speed of the end of the robotic arm exceeds the preset speed critical value.

[0075] Specifically, the speed of the end of the robotic arm is obtained in real time, and the preset speed critical value is set in advance.

[0076] 2. When the speed exceeds the preset speed critical value, trigger the low-damping mode and control the damping value of the robotic arm to decrease.

[0077] Specifically, when the speed of the end of the robotic arm exceeds the preset speed critical value, the robotic arm may be touched at this time. For example, when the patient is abnormally squeezed by the robotic arm, the operator or the patient pushes the robotic arm away forcefully, and at this time, the speed value of the robotic arm will exceed the preset speed critical value. In order to facilitate the movement of the robotic arm, it is necessary to improve the compliance of the robotic arm. Therefore, it is necessary to reduce the damping value of the robotic arm so that the operator or the patient can move the robotic arm more smoothly and avoid injuring the patient.

[0078] 3. When the speed does not exceed the preset speed critical value, maintain the high-precision mode.

[0079] Further, in the low-damping mode, the damping value of the robotic arm is calculated according to the initial impedance coefficient, the speed of the end of the robotic arm, and the impedance coefficient decrease amplitude, and the damping value of the robotic arm is between the first preset damping value and the second preset damping value, where the first preset damping value is greater than the second preset damping value; in the high-precision mode, the damping value of the robotic arm is the first preset damping value.

[0080] Specifically, the calculation formula for the damping value of the robotic arm is expressed as:

[0081]

[0082] Among them, represents the damping value of the robotic arm, represents the joint space speed, represents the velocity of the end of the robotic arm, a represents the initial impedance coefficient, b represents the amplitude of the impedance coefficient decrease, c represents the second preset damping value, B max represents the first preset damping value, where a + c > B max > c > 0, and represents the preset velocity critical value.

[0083] Specifically, in order to achieve variable damping in the horizontal direction to meet more usage scenarios, in this embodiment, the damping is changed according to the absolute value of the Cartesian velocity of the end of the robotic arm, so as to improve the performance in terms of action execution time and accuracy. When the velocity is high, the damping force needs to be reduced so that the operator can drag the end of the robotic arm with the least force and a lot of execution time can be reduced. While in low-speed scanning, increasing the damping can improve the ultrasonic imaging accuracy. Moreover, in order to keep the changing parameters in a stable region, the following function is designed in this embodiment to achieve the function of adaptive scanning:

[0084]

[0085] Substituting the above formula into the τ value calculation formula, the joint torque of the robotic arm can be solved. Among them, a represents the initial impedance coefficient, b represents the amplitude of the impedance coefficient decrease. The larger the b value, the faster the decrease speed; the smaller the b value, the slower the decrease speed. c represents the minimum value to which the impedance coefficient is reduced (to prevent jitter due to too low impedance coefficient), B max represents the maximum value of the impedance coefficient. From the above formula, it can be seen that the damping is equivalent to a negative exponential function related to the velocity of the end of the robotic arm. Please refer to Figure 2 , when the velocity is in , the high-precision mode is enabled. In this mode, the damping is maintained at B max . In this mode, ultrasonic scanning can be performed: when , the impedance is reduced and the low-damping mode is entered. The reduced damping is between c < B < B max . In this mode, the damping is small, and the dragging teaching task can be performed. The robotic arm can be dragged to the target position. Or during the scanning process, when the robotic arm is touched, this mode will also be triggered to prevent potential safety hazards.

[0086] Further, after controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, it further includes:

[0087] When the robotic arm completes the ultrasonic scanning task, control the robotic arm to move away from the human body to the target position and maintain the robotic arm in the high-precision mode.

[0088] Specifically, when the robotic arm is in the high-precision mode, the damping value of the robotic arm is high, and its compliance decreases, enabling the robotic arm to maintain a constant position without deviation.

[0089] Before controlling the ultrasonic robot to perform scanning, the ultrasonic robot scanning control method of this embodiment switches the robotic arm of the ultrasonic robot to the low-damping mode to reduce the damping value of the robotic arm, making the compliance of the robotic arm higher. The operator can drag the robotic arm with low damping, facilitating the operator to place the robotic arm directly above the area of the human body to be scanned. Then, control the robotic arm to move towards the area of the human body to be scanned to contact the human body. When the contact force reaches the target contact force, enter the high-precision mode. In the high-precision mode, the damping value of the robotic arm increases to maintain stable ultrasonic imaging. Moreover, the robotic arm end is controlled to perform the scanning task in real time according to the interaction force and spatial position at the end of the robotic arm, ensuring sufficient contact between the end of the robotic arm and the human body, maintaining the contact force between the end of the robotic arm and the human body within the specified interaction force range, and being able to adaptively follow the undulating movement of the human body surface according to the breathing amplitude of the human body to ensure good ultrasonic imaging effect.

[0090] Figure 3 It is a schematic diagram of the functional modules of the ultrasonic robot scanning control device according to an embodiment of the present invention. As Figure 3 shown, the ultrasonic robot scanning control device 20 includes a preparation module 21 and a scanning module 22.

[0091] The preparation module 21 is configured to control the robotic arm to move towards the area of the human body to be scanned to contact the human body in the low-damping mode, and enter the high-precision mode when the contact force reaches the target contact force;

[0092] The scanning module 22 is configured to, in the high-precision mode, acquire the interaction force and spatial position at the end of the robotic arm in real time, calculate the target joint torque by combining the target contact force, and then control the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque. The damping value in the low-damping mode is lower than the first preset damping value.

[0093] Optionally, when the scanning module 22 performs the operations of acquiring the interaction force and spatial position at the end of the robotic arm in real time, calculating the target joint torque by combining the target contact force, and then controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, it specifically includes: acquiring the interaction force, speed, and spatial position at the end of the robotic arm in real time, calculating the target joint torque by combining the target contact force, and then controlling the robotic arm to perform ultrasonic scanning along a specified trajectory according to the first preset damping value and the target joint torque.

[0094] Optionally, the calculation formula of the target joint torque is expressed as:

[0095]

[0096]

[0097] x e = x d -x a ;

[0098] F froce = K P S F (F a - F d ) + K I ∫S F (F a - F d )dt;

[0099]

[0100]

[0101] where τ represents the target joint torque, F ext is the description of the environmental stress of the six - dimensional force sensor in the tool coordinate system in the base coordinate system or the workpiece coordinate system, x e is the actual pose x a minus the desired pose x d , is the second - order derivative of x e , is the first - order derivative of x e , K is the stiffness coefficient diagonal matrix, B is the damping coefficient diagonal matrix, F froce represents the component in the force - controlled direction, F a is the actual contact force, F d is the target contact force, K P and K I are the error - term parameter and the integral - term parameter of the PI controller respectively, S F represents the diagonal matrix, M(q) represents the robot inertia matrix, represents the Coriolis force and the centrifugal force, g(q) represents the gravity torque, J T (q) represents the transpose of the robot Jacobian matrix, represents the joint - space acceleration, represents the joint - space velocity, q represents the joint - space coordinate vector, represents the Cartesian - space desired velocity, represents the Cartesian - space desired acceleration, J(q) represents the robot Jacobian matrix, represents the inverse of the robot Jacobian matrix.

[0102] Optionally, after the scanning module 22 performs the operation of controlling the robotic arm to perform ultrasonic scanning along a specified trajectory according to the first preset damping value and the target joint torque, it is further configured to: determine whether the speed of the end of the robotic arm exceeds a preset speed threshold; when the speed exceeds the preset speed threshold, trigger a low damping mode and control the damping value of the robotic arm to decrease; when the speed does not exceed the preset speed threshold, maintain the high-precision mode.

[0103] Optionally, in the low damping mode, the damping value of the robotic arm is calculated based on an initial impedance coefficient, the speed of the end of the robotic arm, and an impedance coefficient decrease amplitude, and the damping value of the robotic arm is between a first preset damping value and a second preset damping value, where the first preset damping value is greater than the second preset damping value; in the high-precision mode, the damping value of the robotic arm is the first preset damping value.

[0104] Optionally, the calculation formula for the damping value of the robotic arm is expressed as:

[0105]

[0106] Where represents the damping value of the robotic arm, represents the joint space velocity, represents the speed of the end of the robotic arm, a represents the initial impedance coefficient, b represents the impedance coefficient decrease amplitude, c represents the second preset damping value, B max represents the first preset damping value, where a + c > B max > c > 0, and represents the preset speed threshold.

[0107] Optionally, after the scanning module 22 performs the operation of controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, it is further configured to: when the robotic arm completes the ultrasonic scanning task, control the robotic arm to move away from the human body to a target position and maintain the robotic arm in the high-precision mode.

[0108] For other details of the technical solutions implemented by each module in the ultrasonic robot scanning control device in the above embodiments, reference may be made to the description in the ultrasonic robot scanning control method in the above embodiments, which will not be elaborated here.

[0109] It should be noted that the embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For device embodiments, since they are basically similar to method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments.

[0110] Please refer to Figure 4 ,Figure 4 The structural schematic diagram of the computer device according to an embodiment of the present invention. As Figure 4 shown, the computer device 30 includes a processor 31 and a memory 32 coupled to the processor 31. Program instructions are stored in the memory 32. When the program instructions are executed by the processor 31, the processor 31 is caused to execute the steps of the ultrasonic robot scanning control method described in any of the above embodiments.

[0111] Among them, the processor 31 may also be referred to as a CPU (Central Processing Unit). The processor 31 may be an integrated circuit chip with signal processing capabilities. The processor 31 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0112] Refer to Figure 5 , Figure 5 The structural schematic diagram of the storage medium according to an embodiment of the present invention. The storage medium according to an embodiment of the present invention stores program instructions 41 that can implement the above ultrasonic robot scanning control method. Among them, the program instructions 41 may be stored in the above storage medium in the form of a software product, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc that can store program codes, or a computer device such as a computer, a server, a mobile phone, or a tablet.

[0113] In several embodiments provided in the present application, it should be understood that the disclosed computer devices, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, and the indirect coupling or communication connection of the apparatus or unit may be in an electrical, mechanical, or other form.

[0114] In addition, each functional unit in various embodiments of the present invention may be integrated into one processing unit, may exist physically alone for each unit, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit. The above is only the implementation mode of this application, and does not limit the patent scope of this application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of this application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of this application by the same token.

Claims

1. An ultrasonic robot scanning control method, characterized in that, It includes: In the low-damping mode, control the robotic arm to move towards the area of the human body to be scanned to contact the human body, and when the contact force reaches the target contact force, enter the high-precision mode; In the high-precision mode, the interaction force and spatial position at the end of the robotic arm are obtained in real time, and the target joint torque is calculated by combining the target contact force, and then the robotic arm is controlled to perform ultrasonic scanning according to the first preset damping value and the target joint torque. The damping value in the low-damping mode is lower than the first preset damping value.

2. The ultrasonic robot scanning control method according to claim 1, wherein, The real-time acquisition of the interaction force and spatial position at the end of the robotic arm, the calculation of the target joint torque by combining the target contact force, and then the control of the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque includes: The interaction force, speed and spatial position at the end of the robotic arm are acquired in real time, and the target joint torque is calculated by combining the target contact force, and then the robotic arm is controlled to perform ultrasonic scanning along a specified trajectory according to the first preset damping value and the target joint torque.

3. The ultrasonic robot scanning control method according to claim 2, wherein The calculation formula of the target joint torque is expressed as: x e = x d -x a ; F froce = K P S F (F a - F d ) + K I ∫ S F (F a - F d ) dt; where τ represents the target joint torque, ext is the description of the environmental stress of the six-axis force sensor in the tool coordinate system in the base coordinate system or the workpiece coordinate system, x e is the actual pose x a and the desired pose x d The difference, is the second derivative of x e The second derivative, is the first derivative of x e The first derivative, K is the stiffness coefficient diagonal matrix, B is the damping coefficient diagonal matrix, F froce represents the component in the force control direction, F a is the actual contact force, F d is the target contact force, K P and K I are the error term parameter and the integral term parameter of the PI controller respectively, S F represents the diagonal matrix, M(q) represents the robot inertia matrix, represents the Coriolis force and the centrifugal force, g(q) represents the gravity torque, J T (q) represents the transpose of the robot Jacobian matrix, represents the joint space acceleration, represents the joint space velocity, q represents the joint space coordinate vector, represents the Cartesian space desired velocity, represents the Cartesian space desired acceleration, J(q) represents the robot Jacobian matrix, represents the inverse of the robot Jacobian matrix.

4. The ultrasonic robot scanning control method according to claim 2, wherein After controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, it further includes: Judge whether the speed at the end of the robotic arm exceeds the preset speed critical value; When the speed exceeds the preset speed critical value, trigger the low-damping mode and control the damping value of the robotic arm to decrease; When the speed does not exceed the preset speed critical value, maintain the high-precision mode.

5. The ultrasonic robot scanning control method according to claim 1, characterized in that, In the low-damping mode, the damping value of the robotic arm is calculated according to the initial impedance coefficient, the speed at the end of the robotic arm and the impedance coefficient decrease amplitude, and the damping value of the robotic arm is between the first preset damping value and the second preset damping value, and the first preset damping value is greater than the second preset damping value; In the high-precision mode, the damping value of the robotic arm is the first preset damping value.

6. The ultrasonic robot scanning control method according to claim 5, wherein The calculation formula of the damping value of the robotic arm is expressed as: Among them, represents the damping value of the robotic arm, Cartesian space velocity, represents the velocity at the end of the robotic arm, a represents the initial impedance coefficient, b represents the impedance coefficient decrease, c represents the second preset damping value, B max represents the first preset damping value, where a + c > B max > c > 0, and represents the preset velocity critical value.

7. The ultrasonic robot scanning control method according to claim 1, wherein, After controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque, it further includes: When the robotic arm completes the ultrasonic scanning task, control the robotic arm to move away from the human body to the target position and maintain the robotic arm in the high-precision mode.

8. An ultrasonic robot scanning control device, characterized in that, It includes: A preparation module for controlling the robotic arm to move towards the area of the human body to be scanned to contact the human body in the low-damping mode, and entering the high-precision mode when the contact force reaches the target contact force; A scanning module for, in the high-precision mode, acquiring the interaction force and spatial position at the end of the robotic arm in real time, calculating the target joint torque by combining the target contact force, and then controlling the robotic arm to perform ultrasonic scanning according to the first preset damping value and the target joint torque. The damping value in the low-damping mode is lower than the first preset damping value.

9. A computer device, characterized in that, The computer device includes a processor and a memory coupled to the processor. Program instructions are stored in the memory. When the program instructions are executed by the processor, the processor performs the steps of the ultrasonic robot scanning control method according to any one of claims 1-7.

10. A storage medium, characterized in that, Stores program instructions capable of implementing the ultrasonic robot scanning control method according to any one of claims 1-7.

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