Robot-assisted B-ultrasonic detection system and control method

Abstract

The invention provides a robot-assisted type-B ultrasonic detection system and a control method thereof.The robot-assisted type-B ultrasonic detection system assists an operator in collecting a type-B ultrasonic image of a detected object, and the robot-assisted type-B ultrasonic detection system comprises a type-B ultrasonic probe; an execution end force sensor; a manual push rod end force sensor; the cooperative arm motion control system is designed to be used for controlling the B-ultrasonic probe and the cooperative arm to follow traction of an operator to the cooperative arm according to the contact force and the torque, detected by the execution end force sensor, of the tail end of the B-ultrasonic probe on the basis of a compliant control algorithm; when the B-ultrasonic probe at the tail end of the collaboration arm is moved to a heart expected pose by an operator, the B-ultrasonic probe is automatically controlled to move along the normal direction until the contact force between the B-ultrasonic probe and an examined object is an expected value; and then, based on a compliant control algorithm, enabling the B-ultrasonic probe to keep the contact force at the expected value all the time along with heart fluctuation caused by respiration of an examined object.

Description

Technical Field

[0001] The invention relates to a robot-assisted B-ultrasound detection system and a control method. Background Art

[0002] Surveys show that most deaths due to heart-related diseases are sudden and difficult to be rescued in time. Even patients who are rescued in time have a poor prognosis. In addition, ignoring the early onset of the disease may lead to other related complications such as heart failure. Therefore, it is very important to detect and diagnose heart-related diseases in a timely manner.

[0003] Traditionally, the diagnosis of heart-related diseases is based on a combination of doctor experience and instrumental measurements. Common measurements include cardiac X-rays, cardiac CT scans, cardiac magnetic resonance imaging (MRI), etc. Among them, B-ultrasound is a better method, which has the advantages of being portable, non-invasive, and operable. It is also relatively simple and inexpensive. B-ultrasound can accurately diagnose whether there are any abnormalities in the heart cavity structure and heart function.

[0004] During the B-ultrasound diagnosis process, medical staff need to manually press the B-ultrasound probe on the patient's heart. In order to ensure the quality of the image, it is necessary to ensure that the B-ultrasound probe is in contact with the patient's heart with constant force for a certain period of time, and the doctor needs to frequently change the probe posture to achieve accurate measurement. The whole process is relatively cumbersome and places high demands on the physical strength and operating experience of medical staff. In actual image collection, the collection results often do not meet the diagnostic requirements, and it is often necessary to cycle the operation multiple times, which is extremely inefficient.

[0005] In addition, in the traditional robot point control method, in order to ensure accuracy, the robot exhibits greater rigidity, and a smaller position error will result in a particularly large contact force. If such a control method is used in a robot for B-ultrasound detection, it will be detrimental to the safety of the robot and the inspection object.

[0006] In view of the above situation, there is an urgent need for a device that can assist medical staff in collecting B-ultrasound images. Developing a device that combines B-ultrasound detection instruments with actuators, making full use of the latest research results of electromechanical control, and effectively assisting medical staff in collecting effective color images of the patient's heart area is of great significance for improving image collection efficiency and relieving the pressure of medical staff. Summary of the invention

[0007] In order to solve the above technical problems, the present application proposes a robot-assisted B-ultrasound detection system, which assists operators in collecting B-ultrasound images of the inspection object, and is characterized in that the robot-assisted B-ultrasound detection system includes: a B-ultrasound probe, which is used to press and contact the inspection object and send and receive ultrasonic waves for inspection; an execution end force sensor, wherein the fixed end of the execution end force sensor is connected to the flange end of the collaborative arm, and the loading end of the execution end force sensor is used to install the B-ultrasound probe, and the execution end force sensor is used to detect the contact force and torque at the end of the B-ultrasound probe; a manual push rod end force sensor, wherein the fixed end of the manual push rod end force sensor is connected to the flange end of the collaborative arm, and the loading end of the manual push rod end force sensor is fixed with a push rod, and the manual push rod end force sensor is suitable for detecting the manual operating force and torque applied to the push rod; a collaborative arm motion control system, wherein the The collaborative arm motion control system is designed to control the ultrasound probe and the collaborative arm to follow the operator's traction of the collaborative arm based on the compliant control algorithm according to the contact force and torque at the end of the ultrasound probe detected by the force sensor at the execution end; when it is determined that the direction and value of the manual operating force or torque detected by the force sensor at the manual push rod end meet the expected conditions, the movement of the collaborative arm is stopped; when it is determined that the contact force or torque at the end of the ultrasound probe detected by the force sensor at the execution end is higher than a preset threshold, the movement of the end of the collaborative arm is stopped until the contact force / torque is determined to be within a preset range, and then the movement is resumed; when the ultrasound probe at the end of the collaborative arm is moved to the expected position of the heart by the operator, the ultrasound probe is automatically controlled to move along the normal direction until the contact force between the ultrasound probe and the object of examination is the expected value, and then based on the compliant control algorithm, the ultrasound probe is made to follow the heart fluctuations caused by the breathing of the object of examination to always keep the contact force at the expected value.

[0008] According to a preferred embodiment of the robot-assisted B-ultrasound detection system of the present invention, the loading end of the manual push rod end force sensor is connected to the push rod via a flexible coupling, which is used as a passive compliance protection mechanism.

[0009] According to a preferred implementation form of the robot-assisted B-ultrasound detection system of the present invention, the robot-assisted B-ultrasound detection system also includes a human-computer interaction system, which communicates with the collaborative arm motion control system via wired or wireless means to input control instructions and output status information.

[0010] According to a preferred embodiment of the robot-assisted B-ultrasound detection system of the present invention, the fixed end of the actuator end force sensor and the fixed end of the manual push rod end force sensor are fixed to the flange end of the collaborative arm without coupling with each other. Preferably, the fixed end of the actuator end force sensor and the fixed end of the manual push rod end force sensor are rigidly connected through the same flange of the collaborative arm.

[0011] According to another aspect of the present invention, the present invention also relates to a control method for the above-mentioned robot-assisted B-ultrasound detection system, wherein, after the robot-assisted B-ultrasound detection system is started, it is determined whether a constant force following instruction is received from the human-computer interaction system. If so, the B-ultrasound probe is kept in constant force contact with the inspection object in the normal direction based on a compliant control algorithm, and the contact force is an expected value; if not, it is determined whether the manual operating force or torque applied to the push rod is higher than a preset threshold. If it is higher than the preset threshold, the movement of the end of the collaborative arm is stopped. If it is not higher than the preset threshold, the B-ultrasound probe is ensured to follow the traction of the operator based on the compliant control algorithm.

[0012] According to a preferred implementation form of the control method of the robot-assisted B-ultrasound detection system of the present invention, the posture increment caused by the manual operation of the push rod and the active compliance control increment of the B-ultrasound probe according to the compliance control algorithm superimpose to affect the movement of the B-ultrasound probe.

[0013] According to a preferred implementation form of the control method of the robot-assisted B-ultrasound detection system of the present invention, the position and posture of the B-ultrasound probe is controlled according to the impedance control method expressed by the following formula:

[0014]

[0015] Where Δf is the force / torque deviation between the expected contact force / torque and the actual contact force / torque, Δx is the pose increment obtained by the impedance control algorithm, and are the first and second derivatives of Δx, respectively; m, b, k are the mass, damping, and stiffness coefficients, respectively.

[0016] According to a preferred implementation form of the control method of the robot-assisted B-ultrasound detection system of the present invention, the B-ultrasound probe is manually operated to collect the contact force / torque under ideal conditions, and various values ​​of m, b, and k are set. The position curve, velocity curve, and acceleration curve corresponding to the collected contact force / torque are simulated by computer, and the m, b, and k values ​​corresponding to the curve with smooth changes and the least overshoot are selected as the optimal impedance control parameters. After the optimal impedance control parameters are selected, constant force control and motion following are achieved according to the following formula:

[0017]

[0018] Where Δf is the force / torque deviation between the expected contact force / torque and the actual contact force / torque, Δx is the pose increment obtained by the impedance control algorithm, and are the first and second derivatives of Δx, respectively; m, b, k are the mass, damping, and stiffness coefficients, respectively.

[0019] According to a preferred implementation form of the control method of the robot-assisted B-ultrasound detection system of the present invention, the posture increment threshold and the corresponding rate threshold are adaptively adjusted based on the force deviation between the expected force and the actual force, wherein the posture increment threshold and the corresponding rate threshold are set, and the contact state is determined by the contact force on the B-ultrasound probe. When it is determined to be in contact, the absolute value of the force deviation between the expected force and the actual force is calculated, the first-order derivative and the second-order derivative of the corresponding posture increment are calculated, and PID adaptive adjustment is performed; when it is determined to be not in contact, the posture increment threshold and the corresponding rate threshold do not change, and the previous values ​​are used.

[0020] The beneficial effect of the present invention is that a six-dimensional force sensor is used to perform high-precision detection of the contact force and torque at the end of the B-ultrasound probe, and a compliant control algorithm is used to form a closed-loop control to achieve the purpose of constant force pressing. In order to flexibly control the B-ultrasound probe to reach the desired position in free space, while taking into account the safety and related manual operation requirements in the contact state, the push rod is fixed to the load end of the second force sensor, and the whole is connected to the flange end of the collaborative arm. In actual use, the medical staff manually drags the end of the collaborative arm, and the force sensor detects the manual operation force and torque. Based on compliant control, the B-ultrasound probe is realized to follow the medical staff's operation intention, which is convenient for the B-ultrasound probe in free space to flexibly move to the operation position with the collaborative arm, and at the same time can save the operator's physical strength.

[0021] In addition, the robot can also be triggered to stop by manual push rod during operation to improve the overall system safety factor. At the same time, the contact force and torque range of the B-ultrasound probe can be limited in the manual push rod operation mode. When the preset threshold is exceeded, the system automatically stops the movement of the end of the collaborative arm to avoid damage to the mechanism and the human body.

[0022] Based on the compliant control algorithm, in particular, the B-ultrasound probe can achieve constant force tracking consistent with the heart fluctuations when the heart of the examined object fluctuates due to breathing, and the contact force is always kept at the expected value, thereby ensuring the image quality. In addition, when the B-ultrasound probe has maintained a constant force contact state with the heart based on the compliant control algorithm, the B-ultrasound probe posture can be fine-tuned based on the push rod or external button when the image quality is poor.

[0023] In addition, it can provide functions such as operation point acquisition and storage, controller connection, motion superposition in all directions, constant force pressing, and overall control system shutdown based on the human-computer interaction system (see Figure 5 ) to enable the operator to control and operate flexibly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings. In the drawings:

[0025] Figure 1 The figure schematically shows a collaborative arm assembly mounted on a robot base bracket of a robot-assisted B-ultrasound detection system according to the present invention;

[0026] Figure 2 Schematically showing the components of the cooperation arm of the robot-assisted B-ultrasound detection system according to the present invention;

[0027] Figure 3 The system connection block diagram of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown;

[0028] Figure 4 A simplified control flow chart of a robot-assisted B-ultrasound detection system according to the present invention is schematically shown;

[0029] Figure 5 The interface of the human-computer interaction system of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown;

[0030] Figure 6 The flow of the compliant control algorithm of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown;

[0031] Figure 7 The working principle diagram of the optimal impedance control parameter simulation module of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown;

[0032] Figure 8 The incremental threshold adaptive adjustment module of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown;

[0033] Fig. 9 The figure schematically shows the determination of whether a situation endangers human safety by the robot-assisted B-ultrasound detection system according to the present invention. DETAILED DESCRIPTION

[0034] Figure 1 The collaborative arm assembly 1 mounted on the robot base bracket 2 of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown. Figure 2The various components of the collaborative arm of the robot-assisted B-ultrasound detection system according to the present invention are further schematically shown. The operating handle 7 is connected to the loading end of the manual push rod end force sensor 4 through the flexible coupling 6, and the fixed end of the manual push rod end force sensor 4 is fixedly connected to the manual push rod end connector 5 fixed on the collaborative arm (which is also a flange end of the collaborative arm here). The B-ultrasound probe 3 is used to press and contact the inspection object and send and receive ultrasonic waves for inspection. The B-ultrasound probe 3 is installed on the medical probe fixing ring 9, and then fixedly connected to the collaborative arm through the execution end force sensor 8. The execution end force sensor 8 is used to detect the contact force and torque at the end of the B-ultrasound probe. Its fixed end is connected to the flange end of the collaborative arm, and the loading end is used to install the B-ultrasound probe 3.

[0035] like Figure 3 As shown, the robot-assisted B-ultrasound detection system as a whole includes a collaborative arm 10, and the actuator end force sensor 8 and the manual push rod end force sensor 4 fixed on the collaborative arm 10 communicate with the collaborative arm motion control system 20 (here, an industrial computer) in a wired or wireless manner to provide information about forces and torques. The human-computer interaction system 30 communicates with the collaborative arm motion control system 20 in a wired or wireless manner, receives the control instructions input by the user and provides them to the collaborative arm motion control system 20, and receives the status information output by the collaborative arm motion control system 20, and then provides it to the user. The collaborative arm motion control system 20 can also communicate with another display device 40 in a wired or wireless manner, such as HDMI, to provide the display device 40 with status information that can be displayed. The collaborative arm motion control system 20 communicates with the collaborative arm 10, and adjusts the posture of the collaborative arm according to the user's instructions and the received force and torque information.

[0036] In this structure, since the manual push rod and the B-ultrasound probe are respectively fixed to the rigid structure at the flange end of the collaborative arm, the position and posture of the B-ultrasound probe can be controlled by adjusting the position and posture of the manual push rod.

[0037] Figure 4 A simplified control flow chart of a robot-assisted B-ultrasound detection system according to the present invention is schematically shown. After the robot-assisted B-ultrasound detection system is started, it is determined whether a constant force following instruction is received from the human-computer interaction system. If so, the B-ultrasound probe is kept in constant force contact with the inspection object in the normal direction based on the compliant control algorithm, and the contact force is the expected value. When the reverse force on the push rod is not greater than the threshold, the posture increment based on the manual operation is superimposed on the increment obtained according to the compliant control algorithm; if not, it is determined whether the manual operation force or torque applied to the push rod is higher than the preset threshold. If it is higher than the preset threshold, the movement of the end of the collaborative arm is stopped. If it is not higher than the preset threshold, the B-ultrasound probe is ensured to follow the traction of the operator based on the compliant control algorithm.

[0038] The B-ultrasound probe 3 and the collaborative arm 10 follow the operator's traction of the collaborative arm 10 through the collaborative arm motion control system 20. The collaborative arm motion control system 20 is designed to implement a compliant control algorithm control according to the contact force and torque of the end of the B-ultrasound probe 3 detected by the actuator end force sensor 8.

[0039] For example, when the ultrasound probe at the end of the collaborative arm is moved to the desired position of the heart by the operator, the ultrasound probe is automatically controlled to move along the normal direction until the contact force between the ultrasound probe and the object of examination is the expected value. Then, based on the compliant control algorithm, the ultrasound probe follows the heart fluctuations caused by the breathing of the object of examination to always keep the contact force at the expected value.

[0040] The compliant control algorithm referred to in the present invention is a position-based impedance control method first proposed by the inventor in this field. The robot is equivalent to a "mass-damping-stiffness" model and the environment is equivalent to a spring model. The method flow is as follows: Figure 6 shown.

[0041] exist Figure 6 In, f e is the actual contact force / torque, Δf is f e The force / torque deviation from the expected force / torque, Δx, is the position increment of the end of the collaborative arm. Specifically, the force / torque deviation Δf is transformed into the position increment Δx of the collaborative arm according to the following formula (1):

[0042]

[0043] Among them, x corresponds to the actual posture of the robot, Corresponding to the speed of robot posture change, m, b, and k are mass, damping, and stiffness coefficients, respectively, collectively referred to as impedance parameters.

[0044] like Figure 6 As shown in the figure, the robot joint motion trajectory is inversely solved based on the comparison result of the reference position to be reached by the robot and the above-mentioned posture increment Δx, and the robot joint motion trajectory obtained by inverse kinematics is inversely solved and compared with the robot's actual posture x and posture change speed Compare and control the robot joint movement according to the comparison results.

[0045] Based on impedance parameters m, b, k, current force / torque deviation Δf, posture deviation Δx at the previous moment, and posture deviation rate at the previous moment The incremental acceleration of the posture that meets the dynamic requirements can be obtained On this basis, the incremental velocity of the posture can be obtained based on time integration: Incremental speed of posture By integrating again, we can get the required posture increment current control amount Δx, thus achieving compliant control. This can also be combined with the following Figure 7To understand.

[0046] In order to obtain the best impedance control parameters, that is, the mass coefficient m, the damping coefficient b and the stiffness coefficient k, the collaborative arm is operated by manual teaching. During this process, the end force sensor 8 is executed to obtain the contact force / torque under ideal conditions accordingly. The collected contact force and torque under ideal conditions are input into the design simulation module of the matlab toolbox simulink or similar tools, and various values ​​of m, b, and k are set. The corresponding position curve, velocity curve and acceleration curve are observed, and the parameter combination (mass coefficient m, damping coefficient b and stiffness coefficient k) corresponding to the curve with smooth changes and the least overshoot is selected manually or with the assistance of automation as the best impedance control parameter. Figure 7 The working principle diagram of the optimal impedance parameter simulation module of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown.

[0047] After obtaining the optimal impedance control parameters, constant force control and motion following can be achieved based on the above position-based impedance control method. In specific operations, in order to ensure that the steady-state error changes to zero in an asymptotic manner, the stiffness coefficient k is set to 0. The above equation (1) is simplified to the following equation (2):

[0048]

[0049] Due to the delay of the actual control system, the control result may be inconsistent with the intention. In order to improve the control performance, the present invention introduces a posture / velocity increment threshold adaptive adjustment module based on force / torque deviation to adaptively adjust the posture increment threshold and the corresponding velocity threshold, such as Figure 8 As shown, this can avoid system oscillation problems that may be caused by sensor noise and delay characteristics when the force / torque error is small.

[0050] When performing adaptive adjustment, first set the posture increment threshold and the corresponding posture increment rate threshold, and determine the contact state through the contact force between the robot and the environment. Figure 8 In the embodiment shown, when the contact force is greater than, for example, 3N, it is determined to be in contact. At this time, the absolute value of the deviation between the expected force and the actual force / torque is calculated, the corresponding first-order derivative and second-order derivative are calculated, and the posture increment threshold and the position increment rate threshold are adaptively adjusted based on PID; when it is determined to be non-contact, the threshold does not change, and the previous value is used. Based on this method, the purpose of adaptive adjustment can be achieved.

[0051] In order to make the operation of the device more flexible, the present invention not only provides an automatic image acquisition mode based on constant force control, but also provides a manual image acquisition mode based on a manual push rod. In this mode, the operator holds the push rod operating end and guides the B-ultrasound probe to the desired position. In order to ensure the safety of the patient, the system analyzes the direction and magnitude of the contact force, and terminates the traction function and performs an emergency stop of the robot when it is determined that it may cause discomfort to the patient, and the robot movement is not unlocked until it is determined to be safe.

[0052] Figure 5 The interface of the human-machine interaction system of the robot-assisted B-ultrasound detection system according to the present invention is schematically shown. The human-machine interaction system can be loaded on a tablet computer.

[0053] Fig. 9 The following schematically shows the determination of whether a situation endangers human safety by the robot-assisted B-ultrasound detection system according to the present invention. First, the z-axis of the tool coordinate system at the end of the collaborative arm (here, the B-ultrasound probe) is calculated in the robot base coordinate system, as follows: Fig. 9 As shown by the downward arrow in the figure, and set to: Secondly, obtain the three-dimensional force in the actuator force sensor coordinate system and transform it into the robot reference coordinate system, which is set as: like Fig. 9 As shown by the upward slanting arrow in the figure; finally, the vector and The angle between the two vectors is calculated, and the modulus of the contact force is calculated. When the angle between the two vectors (as shown in the figure) is greater than 90° and the modulus of the three-dimensional force is greater than a threshold value (illustratively 15N in this embodiment), it is determined to be a dangerous situation. That is, the following conditions are met at the same time:

[0054]

[0055] The angle between the z-axis vector of the B-ultrasound probe and the contact force vector is greater than 90°, indicating that the movement of the collaborative arm has caused the B-ultrasound probe to exert pressure on the body of the subject. If the force modulus value is greater than the threshold, it means that the magnitude of the applied pressure has exceeded the preset limit that the body can withstand.

[0056] Therefore, when it is determined that the manual operating force or torque detected by the manual push rod end force sensor is higher than the preset threshold, the movement of the end of the cooperative arm is stopped until the contact force / torque is determined to be within the preset range and the movement is resumed.

[0057] In order to further improve the safety of the system, the time interval for obtaining effective force sensor data can also be counted. When the effective force sensor data is not obtained for more than a certain period of time, it is judged as a system abnormality, the robot stops moving, and the abnormal information is fed back to the handheld PAD end until the contact force / torque is determined to be within the preset range before resuming movement.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various combinations, changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0059] Reference numerals list

[0060] 1 Collaborative arm assembly

[0061] 2 Robot base bracket

[0062] 3. B-ultrasound probe

[0063] 4 Manual push rod end force sensor

[0064] 5 Manual push rod end connector

[0065] 6 Flexible coupling

[0066] 7 Operating handle

[0067] 8 Actuator force sensor

[0068] 9 Medical probe fixing ring

[0069] 10 Collaborative Arm

[0070] 20 Collaborative Arm Motion Control System

[0071] 30 Human-computer interaction system

[0072] 40 Display device

Claims

1. A robot-assisted B-ultrasound detection system, which assists an operator in collecting B-ultrasound images of an inspection object, characterized in that: The robot-assisted B-ultrasound detection system includes: A B-ultrasound probe, the B-ultrasound probe is used to press and contact the inspection object and send and receive ultrasonic waves for inspection; An actuator end force sensor, wherein the fixed end of the actuator end force sensor is connected to the flange end of the collaborative arm, the loading end of the actuator end force sensor is used to install the B-ultrasound probe, and the actuator end force sensor is used to detect the contact force and torque of the end of the B-ultrasound probe; A manual push rod end force sensor, wherein the fixed end of the manual push rod end force sensor is connected to the flange end of the cooperative arm, a push rod is fixed to the loading end of the manual push rod end force sensor, and the manual push rod end force sensor is suitable for detecting the manual operating force and torque applied to the push rod; A collaborative arm motion control system, wherein the collaborative arm motion control system is designed to control the B-ultrasound probe and the collaborative arm to follow the operator's traction of the collaborative arm based on a compliant control algorithm according to the contact force and torque at the end of the B-ultrasound probe detected by the execution end force sensor; when it is determined that the direction and value of the manual operation force or torque detected by the manual push rod end force sensor meet the expected conditions, stop the movement of the collaborative arm; when it is determined that the contact force or torque at the end of the B-ultrasound probe detected by the execution end force sensor is higher than a preset threshold, stop the movement of the end of the collaborative arm until the contact force / torque is determined to be within a preset range before resuming the movement; when the B-ultrasound probe at the end of the collaborative arm is moved to the expected heart position by the operator, automatically control the B-ultrasound probe to move along the normal direction until the contact force between the B-ultrasound probe and the object to be examined is the expected value, and then based on the compliant control algorithm, make the B-ultrasound probe follow the heart fluctuations caused by the breathing of the object to be examined to always keep the contact force at the expected value, The compliant control algorithm transforms the force / torque deviation Δf into the posture increment Δx of the end of the collaborative arm according to the following formula to control the posture of the B-ultrasound probe: Where Δf is the force / torque deviation between the expected contact force / torque and the actual contact force / torque, Δx is the position increment of the end of the collaborative arm, and are the first and second derivatives of Δx, respectively; m, b, and k are the mass coefficient, damping coefficient, and stiffness coefficient, respectively.

2. The robot-assisted B-ultrasound detection system according to claim 1, characterized in that: The loading end of the manual push rod end force sensor is connected to the push rod through a flexible coupling.

3. The robot-assisted B-ultrasound detection system according to claim 1 or 2, characterized in that: The robot-assisted B-ultrasound detection system also includes a human-computer interaction system, which communicates with the collaborative arm motion control system in a wired or wireless manner to input control instructions and output status information.

4. The robot-assisted B-ultrasound detection system according to claim 1 or 2, characterized in that: The fixed end of the actuator end force sensor and the fixed end of the manual push rod end force sensor are respectively fixed to the flange end of the cooperation arm without coupling with each other.

5. The robot-assisted B-ultrasound detection system according to claim 4, characterized in that: The fixed end of the actuator end force sensor and the fixed end of the manual push rod end force sensor are rigidly connected through the same flange of the cooperative arm.

6. A control method for a robot-assisted B-ultrasound detection system according to any one of claims 1 to 5, characterized in that: After the robot-assisted B-ultrasound detection system is started, it is determined whether a constant force following instruction is received from the human-computer interaction system. If so, the B-ultrasound probe is kept in constant force contact with the inspection object in the normal direction based on the compliant control algorithm, and the contact force is the expected value; if not, it is determined whether the manual operating force or torque applied to the push rod is higher than a preset threshold. If it is higher than the preset threshold, the movement of the end of the collaborative arm is stopped. If it is not higher than the preset threshold, the B-ultrasound probe is ensured to follow the traction of the operator based on the compliant control algorithm.

7. The control method of the robot-assisted B-ultrasound detection system according to claim 6, characterized in that: The posture increment caused by the manual operation of the push rod and the active compliance control increment of the B-ultrasound probe according to the compliance control algorithm superimpose to affect the movement of the B-ultrasound probe.

8. The control method of the robot-assisted B-ultrasound detection system according to claim 6, characterized in that: Follow the steps below to determine the mass coefficient m, damping coefficient b, and stiffness coefficient k: Manually operate the B-ultrasound probe to collect the contact force / torque under ideal conditions, Set various values ​​of m, b, and k, and simulate the position curve, velocity curve, and acceleration curve corresponding to the contact force / torque collected by computer. Select the m, b, and k values ​​corresponding to the curve with smooth changes and the least overshoot as the optimal impedance control parameters. After selecting the optimal impedance control parameters, constant force control and motion following are achieved according to the following formula: Where Δf is the force / torque deviation between the expected contact force / torque and the actual contact force / torque, Δx is the pose increment obtained by the impedance control algorithm, and are the first and second derivatives of Δx, respectively; m, b, k are the mass, damping, and stiffness coefficients, respectively.

9. The control method of the robot-assisted B-ultrasound detection system according to claim 6, characterized in that: Based on the force deviation between the expected force and the actual force, the posture increment threshold and the corresponding rate threshold are adaptively adjusted. Among them, the posture increment threshold and the corresponding rate threshold are set, and the contact state is determined by the contact force on the B-ultrasound probe. When it is determined to be in contact, the absolute value of the force deviation between the expected force and the actual force is calculated, the first-order derivative and the second-order derivative of the corresponding posture increment are calculated, and PID adaptive adjustment is performed; when it is determined to be not in contact, the posture increment threshold and the corresponding rate threshold do not change, and the previous values ​​are used.

10. The control method of the robot-assisted B-ultrasound detection system according to claim 6, characterized in that: When no effective force sensor data is obtained for a certain period of time, the movement of the end of the collaborative arm is stopped until the contact force / torque is determined to be within a preset range, and then the movement is resumed.

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