Wave compensation operation cabin control method and system for offshore medical ship

Abstract

The invention relates to the technical field of offshore medical equipment, in particular to a wave compensation operation cabin control method and system for an offshore medical ship, and aims to analyze and predict wave motion by detecting motion parameters of a ship body of the medical ship under the action of waves in real time and adopting a control algorithm. The motion quantity and the target value of adjustment of an adjusting mechanism used for adjusting the position and the posture of the operation cabin are calculated according to the wave motion parameters, the position and the posture of the operation cabin are adjusted according to the motion quantity, finally, the actual position and the posture of the operation cabin are detected in real time, and the detected actual value is compared with the expected target value. The control algorithm is adjusted according to the comparison result, feedback adjustment is achieved, the influence of waves on the operation cabin can be effectively counteracted, a stable operation environment is created for doctors, the operation risk is remarkably reduced, and then the operation success rate is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore medical equipment, and particularly relates to a wave compensation operating cabin control method and system for an offshore medical ship. BACKGROUND

[0002] With the increasing frequency of marine activities, such as deep-sea fishing, marine scientific research, offshore oil exploitation, etc., the number of offshore personnel is increasing, and the situation of sudden illness or injury on the sea also occurs from time to time. In this case, the role of offshore medical ships is becoming more and more important, which can provide timely medical treatment for offshore personnel. However, the offshore environment is complex and changeable, and wave is one of the important factors affecting the normal operation of offshore medical ships.

[0003] In the traditional offshore medical ship, the operating cabin is directly installed on the ship body. Due to the complex motion of the ship body under the action of waves, including pitch, roll, heave, etc. When the ship body pitches, the operating cabin will tilt forward and backward with the ship body, which will change the body position of the patient on the operating table, and the doctor needs to constantly adjust the force and angle when operating the surgical instruments, which increases the difficulty and risk of the operation. For example, during some delicate ophthalmic surgery, even a slight tilt can cause the surgical instruments to deviate from the target position, affecting the operation effect.

[0004] Roll will make the operating cabin sway left and right, which not only makes the doctors and nurses stand unsteadily during the operation, but also may cause the displacement of surgical equipment and medicines. Some high-precision medical equipment, such as microscopes, laser therapy instruments, etc., has very high stability requirements, and slight shaking may affect its normal work, and even cause equipment damage. Heave will make the operating cabin fluctuate up and down, and this vertical motion will also interfere with the operation, especially during long-term operation, the doctor needs to constantly adapt to the fluctuation changes, which is easy to cause fatigue, and then affects the accuracy of the operation.

[0005] In order to solve the influence of waves on the operating cabin, some attempts have been made. For example, some offshore medical ships use simple shock absorbers, but these devices can only reduce the vibration to a certain extent and cannot fundamentally eliminate the influence of waves on the operating cabin. Some other schemes try to adjust the position of the operating cabin by predicting the motion of the waves, but due to the complexity and uncertainty of the wave motion, the effect of this method is not ideal. Therefore, how to effectively compensate for the influence of waves on the operating cabin and ensure the high stability of the operating cabin is a problem to be solved in the current offshore medical field. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a wave compensation operating cabin control method and system for an offshore medical ship to solve the problem that the prior art cannot fundamentally eliminate the influence of waves on the operating cabin.

[0007] In order to achieve the above object, the present application provides a wave compensation operating cabin control method for a sea medical ship, comprising the following steps:

[0008] S1, real-time detection of the motion parameters of the ship body under the action of waves;

[0009] S2, analysis and prediction of the wave motion by using a control algorithm, calculation of the action amount and target value of the adjusting mechanism for adjusting the position and attitude of the operating cabin according to the wave motion parameters;

[0010] S3, adjustment of the position and attitude of the operating cabin according to the action amount;

[0011] S4, real-time detection of the actual position and attitude of the operating cabin, comparison of the detected actual value with the expected target value, and adjustment of the control algorithm according to the comparison result to realize feedback regulation.

[0012] Preferably, in step S1, the process of collecting motion parameters comprises:

[0013] Acceleration signals of the ship body are collected, the sampling frequency satisfies the Nyquist sampling theorem, and noise interference is removed through filtering processing;

[0014] Analog angular velocity signals of the ship body are collected, and after digital processing, the numerical integral method is used to obtain the rotation angle;

[0015] Through further calculation of the acceleration and rotation angle data, the motion parameters of the ship body are obtained, including heave displacement, pitch angle change rate and roll angle change rate.

[0016] Preferably, in step S2, the design steps of the control algorithm comprise:

[0017] Based on the principles of Newtonian mechanics and fluid mechanics, a multi-degree-of-freedom dynamic equation of the ship body including pitch, roll and heave is established, and the moments and forces caused by waves are calculated through linear wave theory;

[0018] A model predictive control algorithm is used to list the system state space equation, solve the finite time domain optimization problem at each sampling time, and meet the constraint conditions;

[0019] The recursive least squares method is used to estimate the model parameters online, and the model parameters are updated through the recursive formula according to the system output vector.

[0020] Preferably, the adjusting mechanism for adjusting the position and attitude of the operating cabin is an electric cylinder, one end of which is fixed on the ship body, and the other end is connected with the platform below the operating cabin, for adjusting the position and attitude of the operating cabin;

[0021] The action amount of the adjusting mechanism for adjusting the position and posture of the surgery cabin in step S2, i.e., the extension and retraction amount of the electric cylinder, specifically comprises:

[0022] The extension and retraction amount of the electric cylinder calculated in step S2 is converted into a pulse signal, the number of pulses is calculated according to the displacement increment of the electric cylinder for each received pulse signal, and the pulse frequency is calculated according to the movement speed of the electric cylinder;

[0023] The movement speed and acceleration of the electric cylinder are constrained, and when the calculated speed exceeds the maximum allowable speed and the acceleration exceeds the maximum allowable acceleration, the speed and acceleration are limited;

[0024] The multiple electric cylinders are coordinately controlled, and the difference between the extension and retraction amounts of different electric cylinders is calculated according to the geometry relationship between the electric cylinders and the posture adjustment requirements of the surgery cabin.

[0025] Preferably, in step S4, the feedback adjustment comprises:

[0026] The actual position and posture data of the surgery cabin are collected;

[0027] The actual position and posture data of the surgery cabin are compared with the expected target value, and the position error vector and the posture error vector are calculated;

[0028] An adaptive fuzzy PID control algorithm is adopted, the proportional coefficient, the integral coefficient and the differential coefficient of the PID controller are adjusted in real time according to the size and the change rate of the position and posture error vectors through the fuzzy inference system;

[0029] According to the adjusted PID parameters, the extension and retraction amounts of the electric cylinders are recalculated through inverse kinematics calculation in combination with the dynamics model of the surgery cabin;

[0030] The position and posture errors of the surgery cabin are monitored in real time, and if the errors persist or exceed the allowable range, the fuzzy inference system rules and the PID parameters are further optimized, and the ship motion model is regularly updated and corrected.

[0031] The application also provides a wave compensation surgery cabin control system for a sea medical ship, which comprises a sea medical ship and a surgery cabin, and further comprises:

[0032] A wave compensation platform for providing support and adjusting the posture of the surgery cabin;

[0033] A plurality of electric cylinders, one end of each electric cylinder being fixed on the ship body of the sea medical ship and the other end being connected to the wave compensation platform through a universal joint;

[0034] A sensor assembly for detecting the movement parameters of the ship body of the sea medical ship under the action of waves in real time;

[0035] The control module is used to analyze and predict wave motion using control algorithms, calculate the amount of motion and target value of the adjustment mechanism for adjusting the position and attitude of the operating cabin based on wave motion parameters, and adjust the position and attitude of the operating cabin based on the amount of motion.

[0036] The control module also detects the actual position and attitude of the operating cabin in real time, compares the detected actual values ​​with the expected target values, and adjusts the control algorithm based on the comparison results to achieve feedback regulation.

[0037] Preferably, the rated load capacity of each electric cylinder meets the following requirements. Where k is the safety factor, The average load that each electric cylinder needs to withstand. ,in It is the acceleration due to gravity. The total weight of the operating room. The number of support points for the platform;

[0038] The stroke of the electric cylinder meets the requirements. ,in, For the direction of the swing, This represents the maximum heave displacement of the ship's hull under wave action. This represents the stroke difference between the two ends of the electric cylinder in the direction of pitching motion. , For pitch angle, This represents the stroke difference between the two ends of the electric cylinder in the lateral movement direction. , For the roll angle, For the length of the wave compensation platform, The width of the wave compensation platform.

[0039] Preferably, the universal joint has the following torque transmission capability. satisfy ,in For torque safety factor, This is the distance from the universal joint to the point of action of the electric cylinder.

[0040] The beneficial effects of this invention are:

[0041] This invention effectively counteracts the impact of waves on the operating room by constructing a wave compensation platform and performing high-precision stable control on it, creating a stable surgical operating environment for doctors, significantly reducing surgical risks, and thus improving the success rate of surgery.

[0042] The application adopts advanced control algorithms such as model predictive control (MPC) to realize real-time analysis and prediction of wave motion.

[0043] The feedback adjustment mechanism of the application adopts an adaptive fuzzy PID control algorithm, which combines the flexibility of fuzzy control and the high precision of PID control, and adjusts the PID parameters in real time according to the error between the actual position and attitude of the surgery cabin and the target value The control algorithm is continuously optimized to ensure control precision and stability. At the same time, the electric cylinder is selected as the actuator, and factors such as load capacity, stroke, and speed are considered in the selection. The installation method is reliable, and the speed and acceleration of the electric cylinder movement are constrained, and multi-cylinder coordinated control is realized. Real-time monitoring and fault diagnosis are realized, and the system has high reliability and response speed, and can accurately execute the control signal in time.

[0044] The application arranges high-precision acceleration sensors and gyroscopes at multiple key positions of the ship body. After the collected analog signals are digitized by the data acquisition module, FIR filter filtering and numerical integration methods are used to accurately calculate the ship body heave displacement , the rate of change of pitch angle , and the rate of change of roll angle , and other motion parameters, to provide reliable data support for the control algorithm. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only a part of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0046] Figure 1 The control method flowchart of the embodiment of the application. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the following will further describe the application in combination with specific embodiments.

[0048] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the present application shall be understood as having the usual meaning as understood by a person with ordinary skill in the art to which the present application pertains. The terms "first", "second" and similar terms used in the present application do not indicate any order, number or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships, which can change accordingly when the absolute positions of the described objects change.

[0049] As Figure 1 shown, the embodiment of the present specification provides a wave compensation operating cabin control method for a sea medical ship, specifically comprising:

[0050] Wave compensation platform construction

[0051] Platform overall design

[0052] In the application scenario of the sea medical ship, the wave compensation platform needs to provide stable support and precise attitude adjustment capability for the operating cabin. According to the size of the operating cabin ( length, width, height) and the total weight (including the weight of the operating cabin itself, internal medical equipment and personnel, etc.), the frame structure of the wave compensation platform is designed. The platform frame is made of high-strength aluminum alloy material, aiming to ensure the structural strength while reducing the weight.

[0053] The platform shape is designed as a rectangle, with length and width , which needs to meet and , where and are safety margins, and the values are in the range of to ensure that the operating cabin can be safely placed on the platform.

[0054] Electric cylinder selection

[0055] As a key executive component of the wave compensation platform, the electric cylinder needs to consider factors such as carrying capacity, stroke, speed, etc. in its selection. According to the total weight of the operating cabin and the number of support points of the platform The average load that each electric cylinder needs to withstand Through formula The calculation shows that, among which Let gravitational acceleration be the acceleration due to gravity, and its value be [value missing]. .

[0056] Considering the dynamic loads generated by wave motion, the rated load capacity of each electric cylinder Must meet ,in For safety, the optimal value is set to be within... .

[0057] electric cylinder stroke It needs to be based on the maximum heave displacement of the hull under wave action. Pitch angle and roll angle To determine this. Assume the platform's length direction is... Axis, width direction is Axis, height direction is axis.

[0058] For helical motion, the electric cylinder stroke must meet the following requirements. For pitching motion, the electric cylinder in travel difference between the two ends of the direction Through formula Calculation; for the lateral motion, the electric cylinder in travel difference between the two ends of the direction Through formula Calculation. Taking all factors into account, the stroke of the electric cylinder... Should meet .

[0059] Electric cylinder movement speed It needs to be based on the frequency of wave motion The maximum stroke variation is used to determine this. Generally, an electric cylinder is required to be able to operate within one wave cycle. The corresponding itinerary adjustments will be completed within the specified time. .

[0060] Electric cylinder installation method

[0061] One end of the electric cylinder is securely fixed to the hull by bolts or other means. To ensure the reliability of the connection, the preload of the bolts is... Must meet ,in For the preload coefficient, the optimal value is taken as follows: .

[0062] The other end of the electric cylinder is connected to the platform below the operating room via a universal joint. The universal joint is designed to flexibly transmit the extension and retraction force of the electric cylinder while allowing the platform to rotate in three degrees of freedom. The universal joint's torque transmission capacity... Must meet ,in The torque safety factor is set to a value of [value missing]. , This is the distance from the universal joint to the point of action of the electric cylinder.

[0063] The construction of the aforementioned wave compensation platform provides a stable and precisely adjustable support platform for the operating room, enabling it to adapt to the complex wave environment at sea.

[0064] Detection of wave motion

[0065] Sensor selection and layout

[0066] In wave motion detection on maritime medical ships, the selection of high-precision accelerometers and gyroscopes is crucial. Accelerometers can measure the acceleration of the hull in all directions, while gyroscopes can accurately measure the hull's rotation angle.

[0067] To obtain comprehensive and accurate information about the ship's motion, accelerometers and gyroscopes are installed at multiple key locations on the hull. For example, sensors are installed at the bow, stern, port and starboard sides, and center of gravity. This arrangement ensures effective monitoring of the overall motion of the ship, as sensors in different locations can capture the differences in motion between different parts of the hull, thus more accurately reflecting the combined impact of waves on the ship.

[0068] Accelerometer data acquisition and processing

[0069] The accelerometer collects data on the ship's hull in the vertical direction ( (axis) and horizontal direction ( shaft and acceleration signal of axis , and These signals are analog signals that vary over time and require digital processing.

[0070] First, the analog signal is converted into a digital signal by a data acquisition module. This module typically employs a high-precision analog-to-digital converter (ADC) with a sampling frequency of... The sampling frequency needs to be selected appropriately based on the frequency characteristics of the wave motion. According to the Nyquist sampling theorem, the sampling frequency... It should be greater than the highest frequency of wave motion. twice as much as, that is .

[0071] The collected acceleration data also need to be filtered to remove noise interference. The commonly used filtering method is the finite impulse response (FIR) filter, and its filtering formula is:

[0072] where, is the input acceleration signal sequence, is the coefficient of the FIR filter, is the order of the filter, is the filtered output signal sequence.

[0073] Gyroscope data acquisition and processing

[0074] The gyroscope is used to measure the rotation angle of the ship body, including the pitch angle , roll angle and yaw angle . The gyroscope outputs angular velocity signals , and , respectively corresponding to the rotation speed of the three coordinate axes.

[0075] Similarly, the analog signal output by the gyroscope needs to be digitized by the data acquisition module. The collected angular velocity data needs to be integrated to obtain the rotation angle. Numerical integration methods such as trapezoidal integration method are adopted, and its calculation formula is:

[0076] where, is the sampling period, , and are the current pitch, roll and yaw angles, , and are the angles at the last time.

[0077] Comprehensive calculation of wave motion parameters

[0078] After obtaining the acceleration and rotation angle data, the motion parameters of the ship body can be further calculated, such as the heave displacement , pitch angle change rate and roll angle change rate .

[0079] The heave displacement can be obtained by integrating the vertical acceleration twice. Using the trapezoidal integration method, the first integration obtains the vertical velocity :

[0080] Second integration gives heave displacement :

[0081] Pitch angle rate of change and roll angle rate of change can be obtained by differentiating pitch angle and roll angle :

[0082] Through the above steps, the motion parameters of the ship under the action of waves can be accurately detected, providing reliable data support for the subsequent control algorithm.

[0083] Design of control algorithm

[0084] Establishment of ship motion model

[0085] Considering the complex motion of the ship under the action of waves, a multi-degree-of-freedom motion model is established. The motion of the ship mainly includes pitch , roll and heave . Based on the principles of Newtonian mechanics and fluid mechanics, we can obtain the following dynamic equations:

[0086] For pitch motion:

[0087] where, is the moment of inertia of the ship around the pitch axis, is the pitch damping coefficient, is the pitch stiffness coefficient, is the pitch moment caused by waves.

[0088] For roll motion:

[0089] where, is the moment of inertia of the ship around the roll axis, is the roll damping coefficient, is the roll stiffness coefficient, is the roll moment caused by waves.

[0090] For heave motion:

[0091] where, is the mass of the hull, is the heave damping coefficient, is the heave stiffness coefficient, is the wave-induced heave force.

[0092] The wave-induced moments and forces can be calculated by linear wave theory. Assuming the wave is regular, its expression is:

[0093] where, is the wave amplitude, is the wave number, is the wave circular frequency, is the initial phase.

[0094] According to linear wave theory, the wave-induced pitch moment , roll moment and heave force can be expressed as functions of wave parameters and hull parameters.

[0095] Application of model predictive control (MPC) algorithm

[0096] Model predictive control (MPC) is a model-based optimization control method, which solves a finite-time optimization problem at each sampling time to obtain the current control input by predicting the future behavior of the system.

[0097] Let the state vector of the system be , and the control input vector be , where represents the extension amount of the th electric cylinder.

[0098] The state space equation of the system can be expressed as:

[0099] where, is the system matrix, is the input matrix, is the process noise.

[0100] The prediction horizon is , and the control horizon is At each sampling time , the MPC algorithm solves the following optimization problem:

[0101] subject to:

[0102] where, and are weighting matrices for adjusting the weights of state error and control input; and are upper and lower limits of control input, and are upper and lower limits of state variable.

[0103] Updating and correction of model

[0104] Due to the complexity and uncertainty of wave motion, the motion model of the ship needs to be updated and corrected according to the real-time data detected by the sensors. Recursive least squares (RLS) is used to estimate the model parameters online.

[0105] Let the output vector of the system be According to the state space equation of the system, we can get:

[0106] where, is the output matrix, is the measurement noise.

[0107] The update formula of recursive least squares is:

[0108] where, is the estimated value of model parameters, is the regression vector, is the covariance matrix, is the forgetting factor.

[0109] By continuously updating the model parameters, the model can better reflect the actual motion of the ship under the action of waves, thereby improving the accuracy and adaptability of the control algorithm.

[0110] Control of electric cylinder

[0111] Control signal conversion

[0112] The control system needs to convert the extension and retraction amount of the electric cylinder calculated based on the model predictive control (MPC) algorithm into a control signal suitable for the electric cylinder to execute. The electric cylinder is usually controlled by pulse signals, and the number and frequency of pulse signals determine the extension and retraction amount and speed of the electric cylinder.

[0113] Let the displacement increment of the electric cylinder for each received pulse signal be , then the number of pulses needed to be sent is The pulse frequency can be calculated by the following formula:

[0114] Pulse frequency is related to the movement speed of the electric cylinder. The movement speed of the electric cylinder is known , the pulse frequency can be calculated by the extension amount and the desired movement time , that is . Since each pulse corresponds to an incremental displacement , the pulse frequency can be expressed as:

[0115] In the application background of the offshore medical ship, due to the uncertainty of wave motion, the desired movement time needs to be dynamically adjusted according to the changes of the wave to ensure that the electric cylinder can respond to the influence of the wave on the operation cabin in time.

[0116] Constraints on the movement of the electric cylinder

[0117] In the control process, the movement speed and acceleration of the electric cylinder need to be ensured within a reasonable range to avoid excessive impact on the operation cabin. The maximum allowable speed and the maximum allowable acceleration of the electric cylinder are pre-set parameters, and the calculated speed and acceleration need to be constrained during control.

[0118] The acceleration of the electric cylinder can be calculated by the rate of change of speed. Let the speed at the current time be , the speed at the next time be , and the acceleration be:

[0119] In order to ensure that the movement of the electric cylinder is within a safe range, when the calculated speed exceeds the maximum allowable speed , the speed needs to be limited, that is:

[0120] Similarly, when the calculated acceleration exceeds the maximum allowable acceleration , the acceleration needs to be limited, that is: ​

[0121] Multi-cylinder coordinated control

[0122] Since the wave-compensated platform is supported by multiple electric cylinders, in order to ensure the stability of the surgical cabin, the multiple electric cylinders need to be coordinated and controlled. Suppose there are electric cylinders in total, the extension amount of the electric cylinder is , the corresponding pulse number is , and the pulse frequency is .

[0123] In the control process, the motion of each electric cylinder needs to be adjusted according to the attitude adjustment requirements of the surgical cabin to ensure that they work cooperatively. For example, when the ship body rolls, the front and rear electric cylinders need to be extended or retracted to different degrees to maintain the level of the surgical cabin. Suppose the roll angle of the surgical cabin is , according to the geometric relationship, the difference between the extension amounts of the front and rear electric cylinders and the roll angle can be calculated as:

[0124] where is the horizontal distance between the front and rear electric cylinders.

[0125] By reasonably distributing and coordinating the extension amounts of each electric cylinder, the influence of waves on the surgical cabin can be effectively offset, and the high stability of the surgical cabin can be ensured.

[0126] Real-time monitoring and fault diagnosis of electric cylinders

[0127] In the control process of electric cylinders, their running state needs to be monitored in real time. Through sensors installed on the electric cylinders, such as current sensors and position sensors, the current and position information of the electric cylinders can be obtained in real time.

[0128] Suppose the normal working current range of the electric cylinder is , when the detected current exceeds this range, it may indicate that the electric cylinder has a fault. At this time, the control system needs to issue an alarm in time and take appropriate measures, such as stopping the movement of the electric cylinder, to avoid damaging the surgical cabin.

[0129] At the same time, by monitoring the position information of the electric cylinder in real time, it can be judged whether the electric cylinder moves according to the expected extension amount. If the error between the actual position and the expected position exceeds a certain threshold, the control algorithm needs to be adjusted to improve the control accuracy.

[0130] Feedback regulation

[0131] Sensor arrangement and data acquisition

[0132] Position sensors are placed on the surgical capsule to accurately measure its position coordinates in three-dimensional space Attitude sensors are used to obtain the attitude information of the surgical capsule, usually represented by Euler angles where is the roll angle, is the pitch angle, is the yaw angle.

[0133] After the sensors convert the detected analog signals into digital signals, they are collected by a high-speed data acquisition module. The acquisition frequency needs to be reasonably selected according to the characteristics of wave motion and the requirements of the control algorithm, generally satisfying the Nyquist sampling theorem, i.e. where is the highest frequency of the wave motion signal. The collected data is transmitted in real time to the control system through a communication interface (such as Ethernet, CAN bus, etc.).

[0134] Error calculation

[0135] After the control system receives the actual position and attitude data of the surgical capsule, it compares them with the desired target values. Let the actual position vector be and the target position vector be , then the position error vector is:

[0136] Similarly, let the actual attitude vector be and the target attitude vector be , then the attitude error vector is:

[0137] Control algorithm adjustment

[0138] Based on the calculated position error vector and attitude error vector , the control algorithm is adjusted. Here, an adaptive fuzzy PID control algorithm is used, which combines the flexibility of fuzzy control and the high precision of PID control.

[0139] The output of a traditional PID controller can be represented as:

[0140] where, is the proportional coefficient, is the integral coefficient, is the differential coefficient, is the error signal.

[0141] In adaptive fuzzy PID control, according to the size and rate of change of error vector and , the values of , and are adjusted in real time through a fuzzy inference system. The inputs of the fuzzy inference system are error and error rate , and the outputs are , and . The specific fuzzy rules can be designed according to practical application experience and experimental results.

[0142] The adjusted PID parameters are:

[0143] Electric cylinder extension amount recalculation

[0144] According to the adjusted PID parameters, the extension amount of the electric cylinder is recalculated. Let the number of electric cylinders be , and the extension amount of the th electric cylinder be .

[0145] Considering the dynamics model of the surgical cabin, the motion equation of the surgical cabin can be obtained according to the Newton-Euler equation:

[0146] where is the mass matrix of the surgical cabin, is the generalized coordinate vector, is the Coriolis force and centrifugal force matrix, is the gravity vector, is the force vector applied by the electric cylinder.

[0147] Through inverse kinematics calculation, the adjusted control signal is converted into the extension amount of each electric cylinder to realize accurate adjustment of the position and attitude of the surgical cabin, so that the actual position and attitude of the surgical cabin continuously approach the target value.

[0148] Real-time monitoring and optimization

[0149] During the feedback adjustment process, the position and attitude errors of the surgical cabin are monitored in real time. If the errors persist or exceed the allowed range, the rules of the fuzzy inference system and the PID parameters are further optimized. At the same time, considering the time-varying and uncertainty of wave motion, the ship motion model is updated and corrected regularly to improve the adaptability and stability of the control algorithm.

[0150] It should be understood by those of ordinary skill in the art that the above discussion of any of the embodiments is merely exemplary and is not intended to suggest the scope of the present application is limited to these examples; the above embodiments or technical features among different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in detail for the sake of brevity. Any omissions, modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A wave-compensated operating room control method for a marine medical ship, characterized in that, Includes the following steps: S1. Real-time detection of motion parameters of the medical ship's hull under wave action; S2. The control algorithm is used to analyze and predict the wave motion, and the motion amount and target value of the adjustment mechanism used to adjust the position and attitude of the operating cabin are calculated based on the wave motion parameters. S3. Adjust the position and posture of the operating cabin according to the amount of movement; S4. Real-time detection of the actual position and attitude of the operating cabin, comparison of the detected actual value with the expected target value, and adjustment of the control algorithm based on the comparison result to achieve feedback regulation.

2. The wave-compensated operating room control method for a marine medical ship according to claim 1, characterized in that, Step S1, the process of collecting motion parameters includes: Acceleration signals of the ship's hull are collected, the sampling frequency satisfies the Nyquist sampling theorem, and noise interference is removed through filtering. The simulated angular velocity signal of the ship's hull was collected, and after digital processing, the rotation angle was obtained by numerical integration. By further calculating the acceleration and rotation angle data, the motion parameters of the hull are obtained, including heave displacement, rate of change of pitch angle, and rate of change of roll angle.

3. The wave-compensated operating room control method for a marine medical ship according to claim 2, characterized in that, In step S2, the design steps of the control algorithm include: Based on the principles of Newtonian mechanics and fluid mechanics, a multi-degree-of-freedom dynamic equation for the hull is established, including motions in three directions: pitch, roll, and heave. The torques and forces caused by waves are calculated using linear wave theory. The model predictive control algorithm is adopted to list the system state-space equations, solve the finite-time optimization problem at each sampling time, and satisfy the constraints. The recursive least squares method is used to estimate the model parameters online, and the model parameters are updated according to the system output vector through a recursive formula.

4. The wave-compensated operating room control method for a marine medical ship according to claim 1, characterized in that, The adjustment mechanism used to adjust the position and attitude of the operating cabin is an electric cylinder. One end of the electric cylinder is fixed to the hull, and the other end is connected to the platform below the operating cabin. It is used to adjust the position and attitude of the operating cabin. The amount of motion of the adjustment mechanism for adjusting the position and posture of the surgical cabin mentioned in step S2, i.e., adjusting the extension and retraction of the electric cylinder, then step S3 specifically includes: The extension and retraction of the electric cylinder calculated in step S2 is converted into a pulse signal. The number of pulses is calculated based on the displacement increment of the electric cylinder for each pulse signal received, and the pulse frequency is calculated based on the movement speed of the electric cylinder. Constraints are imposed on the movement speed and acceleration of the electric cylinder. When the calculated speed exceeds the maximum permissible speed or the acceleration exceeds the maximum permissible acceleration, the speed and acceleration are limited. Multiple electric cylinders are coordinated and controlled. Based on the surgical cabin posture adjustment requirements, the difference in extension and retraction of different electric cylinders is calculated through the geometric relationship between them.

5. The wave-compensated operating room control method for a marine medical ship according to claim 1, characterized in that, In step S4, the feedback adjustment includes: Collect data on the actual position and attitude of the operating cabin; Compare the actual position and attitude data of the operating cabin with the expected target value, and calculate the position error vector and attitude error vector; An adaptive fuzzy PID control algorithm is adopted, which adjusts the proportional coefficient, integral coefficient and derivative coefficient of the PID controller in real time through a fuzzy inference system based on the magnitude and rate of change of the position and attitude error vector. Based on the adjusted PID parameters and combined with the operating room dynamics model, the extension and retraction of the electric cylinder are recalculated through inverse kinematics calculations. The position and attitude errors of the operating cabin are monitored in real time. If the error persists or exceeds the allowable range, the rules and PID parameters of the fuzzy inference system are further optimized, and the hull motion model is updated and corrected regularly.

6. A wave-compensated operating room control system for a marine medical vessel, comprising a marine medical vessel and an operating room, characterized in that, Also includes: A wave compensation platform is used to provide support and adjust the attitude of the operating cabin. Several electric cylinders, one end of which is fixed to the hull of the offshore medical ship, and the other end of which is connected to the wave compensation platform via a universal joint; Sensor components are used to detect the motion parameters of the medical ship's hull under wave action in real time; The control module is used to analyze and predict wave motion using control algorithms, calculate the amount of motion and target value of the adjustment mechanism for adjusting the position and attitude of the operating cabin based on wave motion parameters, and adjust the position and attitude of the operating cabin based on the amount of motion. The control module also detects the actual position and attitude of the operating cabin in real time, compares the detected actual values ​​with the expected target values, and adjusts the control algorithm based on the comparison results to achieve feedback regulation.

7. The wave-compensated operating room control system for a marine medical ship according to claim 6, characterized in that, The rated load capacity of each electric cylinder meets the requirements. Where k is the safety factor, The average load that each electric cylinder needs to withstand. ,in It is the acceleration due to gravity. The total weight of the operating room. The number of support points for the platform; The stroke of the electric cylinder meets the requirements. ,in, For the direction of the swing, This represents the maximum heave displacement of the ship's hull under wave action. This represents the stroke difference between the two ends of the electric cylinder in the direction of pitching motion. , For pitch angle, This represents the stroke difference between the two ends of the electric cylinder in the lateral movement direction. , The tilt angle, For the length of the wave compensation platform, The width of the wave compensation platform.

8. The wave-compensated operating room control system for a marine medical ship according to claim 7, characterized in that, The torque transmission capability of the universal joint satisfy ,in For torque safety factor, This is the distance from the universal joint to the point of action of the electric cylinder.

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