A control method and system for a medical mobile bed silent push rod auxiliary device

Abstract

The present application relates to the technical field of push rod control, and specifically provides a medical mobile bed silent push rod auxiliary device control method and system, the method comprising: obtaining a rotation speed synchronization error, constructing an adaptive fuzzy PID controller based on the rotation speed synchronization error; obtaining a rotation speed prediction error, and constructing a prediction compensator for compensating for the acceleration mutation in advance based on the rotation speed prediction error; obtaining a real-time control signal according to the adaptive fuzzy PID controller and the prediction compensator, and controlling two groups of silent push rod motors based on the real-time control signal. The present application constructs an adaptive fuzzy PID controller and a prediction compensator, uses the prediction compensator to process the acceleration change in the start-stop phase in advance, combines fuzzy logic to deal with nonlinear load, can eliminate the response difference (such as start-stop time difference, speed fluctuation) in the operation of the double silent push rod motors of the medical displacement bed, and avoid the shaking problem caused thereby.

Description

Technical Field

[0001] This invention relates to the field of push rod control technology, and more specifically, to a control method and system for a silent push rod auxiliary device for a medical mobile bed. Background Technology

[0002] Medical mobile beds are medical devices used for disease prevention, diagnosis, treatment and nursing. They consist of an ABS headboard, an electric linear drive, a controller and other components. The bed frame is made of double-layer steel welded and equipped with silent universal wheels. It can realize the functions of overall lifting, leg bending (0-50°) and left and right turning (0-60°) through electric control. It is suitable for the treatment and transfer of patients in ICU and general wards.

[0003] Medical mobile beds typically use push rod motors to achieve overall lifting and lowering of the bed board. Most products on the market use ordinary push rod motors, which generally suffer from high noise levels, simple structure, and lower requirements for manufacturing processes and materials. These are suitable for scenarios with low performance requirements, such as industrial equipment, agricultural machinery, and warehousing equipment where noise is not a primary concern. Ordinary push rod motors generate significant vibration and noise during operation, and long-term use may lead to faster component wear, affecting equipment lifespan and user experience.

[0004] Ordinary linear actuator motors, due to low gear precision, insufficient lubrication, and unoptimized structural design, typically produce noise levels exceeding 50 decibels during operation and are prone to vibration, causing equipment shaking or jamming, affecting performance and accelerating component wear. To reduce vibration, some existing technologies employ dual-motor drives and / or PID control methods; however, due to differences in the responses of the two motors (such as inconsistent start-stop times and speed fluctuations), existing technologies still cannot effectively eliminate high-frequency jitter. Summary of the Invention

[0005] Based on this, in order to reduce and eliminate the shaking phenomenon during the lifting and lowering of the medical cart, the present invention provides a control method and system for a silent push rod auxiliary device for a medical mobile bed, the specific technical solution of which is as follows:

[0006] A control method for a silent push rod auxiliary device for a medical mobile bed includes the following steps: Two sets of silent push rods are symmetrically installed at a preset angle on the medical mobile bed. The two sets of silent push rod motors are used to raise and lower the bed board. The first speed of the first group of silent push rod motors and the second speed of the second group of silent push rod motors are obtained. The speed synchronization error is obtained based on the first speed and the second speed. An adaptive fuzzy PID controller is constructed based on the speed synchronization error to cope with nonlinear disturbances caused by load changes. The speed prediction error between the first group of silent push rod motors and the second group of silent push rod motors is obtained, and a predictive compensator is constructed based on the speed prediction error to compensate for sudden acceleration changes during start-stop in advance. Real-time control signals are obtained using an adaptive fuzzy PID controller and a predictive compensator, and two sets of silent push rod motors are controlled based on these real-time control signals.

[0007] The control method for the silent push rod auxiliary device of the medical moving bed constructs an adaptive fuzzy PID controller and a predictive compensator. The predictive compensator preprocesses the acceleration changes during the start-stop phase and combines fuzzy logic to deal with nonlinear loads. This can eliminate the response differences (such as start-stop time difference and speed fluctuation) in the operation of the dual silent push rod motors of the medical moving bed and avoid the jitter problem caused by them.

[0008] Preferably, the specific method for constructing an adaptive fuzzy PID controller includes the following steps: Obtain the proportional gain, integral gain, and derivative gain; and obtain the proportional term based on the proportional gain and the speed synchronization error. Obtain the synchronization error threshold, and obtain the integral term based on the integral gain and the speed synchronization error. When the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to be zero. The speed synchronization error is filtered and smoothed, and the differential term is obtained based on the differential gain and the speed synchronization error after filtering and smoothing. An adaptive fuzzy PID controller is constructed based on the proportional, integral, and derivative terms.

[0009] Preferably, the specific method for constructing the predictive compensator includes the following steps: Obtain the error difference between the speed prediction error and the speed synchronization error, and perform a weighted summation of the error difference to obtain the error compensation value; Obtain the compensation intensity coefficients used to balance predictive compensation and real-time control, and construct a predictive compensator based on the compensation intensity coefficients and error compensation values.

[0010] Preferably, the adaptive fuzzy PID controller is represented as follows: ; in, These represent proportional gain, integral gain, and derivative gain, respectively. These represent the speed synchronization error and the speed synchronization error after filtering and smoothing, respectively. This represents a saturation function, used to limit the upper limit of integration.

[0011] Preferably, the predictive compensator is represented as ; in, These represent the compensation strength coefficient and the error compensation value, respectively. Indicates the first The contribution weight of each prediction time.

[0012] Preferably, the real-time control signal Represented as .

[0013] A control system for a silent push rod auxiliary device for a medical mobile bed, used to implement the control method for the silent push rod auxiliary device for the medical mobile bed, comprising: The PID controller construction module is used to obtain the first speed of the first group of silent push rod motors and the second speed of the second group of silent push rod motors, obtain the speed synchronization error based on the first speed and the second speed, and construct an adaptive fuzzy PID controller to cope with nonlinear disturbances caused by load changes based on the speed synchronization error. The predictive compensator construction module is used to obtain the speed prediction error between the first group of silent push rod motors and the second group of silent push rod motors, and to construct a predictive compensator based on the speed prediction error to compensate for sudden acceleration changes during start-stop in advance. The real-time control signal acquisition module is used to acquire real-time control signals based on the adaptive fuzzy PID controller and the predictive compensator, and to control two sets of silent push rod motors based on the real-time control signals.

[0014] Preferably, the PID controller construction module includes: Gain coefficient acquisition unit, used to acquire proportional gain, integral gain and derivative gain; The proportional term acquisition unit is used to acquire the proportional term based on the proportional gain and the speed synchronization error. The integral term acquisition unit is used to acquire the synchronization error threshold. It acquires the integral term based on the integral gain and the speed synchronization error. When the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to be zero. The differential term acquisition unit is used to filter and smooth the speed synchronization error, and to obtain the differential term based on the differential gain and the speed synchronization error after filtering and smoothing. The PID controller building unit is used to construct an adaptive fuzzy PID controller based on the proportional, integral, and derivative terms.

[0015] Preferably, the predictive compensator building module includes: The error compensation value acquisition unit is used to acquire the error difference between the speed prediction error and the speed synchronization error, and to perform a weighted summation of the error difference to obtain the error compensation value. The predictive compensator construction unit is used to obtain the compensation intensity coefficient for balancing predictive compensation and real-time control, and to construct the predictive compensator based on the compensation intensity coefficient and the error compensation value.

[0016] Preferably, the medical mobile bed includes an X-shaped support arm, a frame, and a bed board. One end of the X-shaped support arm is hinged to the frame, and the other end of the X-shaped support arm is hinged to the bed board. One end of the silent push rod is hinged to the frame, and the other end of the silent push rod is hinged to the upper crossbar of the support arm. Attached Figure Description

[0017] The invention will be further understood from the following description taken in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but rather the emphasis is on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0018] Figure 1 This is a schematic diagram of the overall process of a control method for a silent push rod auxiliary device for a medical mobile bed according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating a specific method for constructing an adaptive fuzzy PID controller in one embodiment of the present invention; Figure 3 This is a flowchart illustrating a specific method for constructing a predictive compensator in one embodiment of the present invention; Figure 4 This is a schematic diagram of the lifting base frame in one embodiment of the present invention; Figure 5 This is a schematic diagram of the lifting frame structure in one embodiment of the present invention; Figure 6 This is a schematic diagram of the inclined tube frame in one embodiment of the present invention; Figure 7 This is a schematic diagram of the structural relationship between the lifting frame and the X-shaped support arm in one embodiment of the present invention.

[0019] Explanation of reference numerals in the attached diagram: 1. X-shaped support arm; 2. Silent push rod; 3. Inclined tube frame; 4. Lifting upper frame; 5. Motor mounting base; 6. Frame; 7. Movable seat. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0021] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] In this invention, "first" and "second" do not represent a specific quantity or order, but are merely used to distinguish names.

[0024] Before describing the specific embodiments of the present invention, a brief introduction to the prior art will be given first.

[0025] Most products on the market use ordinary linear actuator motors, which generally suffer from problems such as high noise, simple structure, and low requirements for manufacturing processes and materials. They are suitable for scenarios with low performance requirements, such as industrial equipment, agricultural machinery, and warehousing equipment where noise is not a major concern. However, ordinary linear actuator motors generate significant vibration and noise during operation, and long-term use may lead to faster wear of components, affecting equipment lifespan and user experience.

[0026] Overall, ordinary linear actuator motors have the following two problems: 1. Excessive noise and unstable operation. Due to low gear precision, insufficient lubrication, and unoptimized structural design, the noise level during operation is usually higher than 50 decibels, and vibration is easily generated, causing the equipment to shake or jam, affecting performance and accelerating component wear.

[0027] 2. Short lifespan, low energy efficiency, limited applicable scenarios, and lack of intelligent control. Ordinary linear actuator motors are made of inferior materials, are prone to wear and tear with long-term use, have high energy consumption, and are mainly suitable for industrial and agricultural scenarios where noise is not a major concern. They are difficult to meet the needs of quiet places such as hospital wards and nursing homes, and do not have intelligent control functions.

[0028] To address these issues, our medical transfer bed utilizes a high-precision, low-noise, smooth-running, and long-life silent push rod motor, combined with an optimized auxiliary structure, which helps resolve the pain points of traditional push rod motors. The silent push rod motor operates at less than 30 decibels, ensuring a quiet and comfortable medical environment. Furthermore, high-precision gears and high-quality lubricating materials significantly extend its service life and reduce maintenance costs.

[0029] To further enhance the performance of our medical transfer bed, we have developed a customized auxiliary structure, including shock-absorbing design, intelligent control, lightweight materials, and user-friendly operation. The shock-absorbing design further reduces vibration and noise during operation, while the intelligent control system enables precise positioning and speed adjustment, ensuring a smooth and safe transfer process. Lightweight materials reduce the weight of the equipment while maintaining structural stability, and the user-friendly design facilitates operation for medical staff, reducing their workload. Our medical transfer bed, with its silent push-rod motor and optimized auxiliary structure, is particularly suitable for hospitals, nursing facilities, rehabilitation centers, and home care settings, providing users with a quiet, safe, and comfortable transfer experience while improving nursing efficiency and patient comfort.

[0030] The jitter is mainly caused by differences in the responses of the two motors (such as inconsistent start-stop times and speed fluctuations). Traditional methods (such as fixed PID control) are insufficient to eliminate high-frequency jitter, especially in scenarios involving load variations in medical transfer beds. To reduce and eliminate jitter during the lifting and lowering of the medical cart, such as... Figure 1 As shown, an embodiment of the present invention provides a control method for a silent push rod auxiliary device for a medical mobile bed, comprising the following steps: S1, two sets of silent push rods are symmetrically installed at a preset angle on the medical mobile bed. The two sets of silent push rod motors are used to realize the lifting and lowering of the bed board.

[0031] S2, obtain the first speed of the first group of silent push rod motors and the second speed of the second group of silent push rod motors, obtain the speed synchronization error based on the first speed and the second speed, and construct an adaptive fuzzy PID controller to cope with nonlinear disturbances caused by load changes based on the speed synchronization error.

[0032] Assuming the first and second rotational speeds are represented as v1(t) and v2(t) respectively, the rotational speed synchronization error can be defined. Let |v1(t) - v2(t)| be the value. A traditional PID controller can be expressed as... However, its fixed gain is prone to failure under high loads. Among them, These represent proportional gain, integral gain, and differential gain, respectively.

[0033] As a preferred technical solution, such as Figure 2 As shown, the specific method for constructing an adaptive fuzzy PID controller includes the following steps: S21, obtain the proportional gain, integral gain and derivative gain, and obtain the proportional term based on the proportional gain and the speed synchronization error.

[0034] The proportional gain is mainly used to dynamically adjust the proportional control strength, with an initial value between 0.8 and 2.0. The corresponding fuzzy rule is: if the speed synchronization error is large, the gain increases by 50%. The integral gain is used to eliminate accumulated errors, with an initial value between 0.1 and 0.5 to avoid oscillation caused by integral saturation. The derivative gain is mainly used to suppress sudden changes, with an initial value generally between 0.5 and 1.2 to suppress the instantaneous impact during start-stop.

[0035] Generally speaking, the larger the proportional gain, the faster the response, but the more prone to overshoot; the larger the integral gain, the higher the steady-state accuracy, but the slower the response; the larger the derivative gain, the better the suppression of overshoot, but the more sensitive to noise.

[0036] S22, obtain the synchronization error threshold, obtain the integral term based on the integral gain and the speed synchronization error, wherein when the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to be zero.

[0037] When the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to zero, and only PD control is used; the integral is only activated when the absolute value of the speed synchronization error enters the dead zone, which can avoid overshoot.

[0038] The integral term can be understood as the sum of historical accumulated errors, and it is mainly used to address persistent small offsets. Saturation can be prevented by limiting the upper limit of the integral.

[0039] Integral saturation can cause the motor to continue applying force after reaching the target position until the integral term diminishes, potentially damaging the lead screw and gearbox. This is addressed by limiting the upper limit of the integral term to prevent saturation. When the real-time control signal reaches the saturation limit, the accumulation of the integral term is frozen, thus resisting integral saturation and reducing mechanical shock.

[0040] S23, perform filtering and smoothing on the speed synchronization error, and obtain the differential term based on the differential gain and the speed synchronization error after filtering and smoothing.

[0041] Because the speed sensor (such as the encoder) of the medical bed will have quantization noise when running at low speed, if the speed synchronization error is directly differentiated, the high-frequency noise will be greatly amplified, directly driving the motor to produce high-frequency micro-vibration, which will increase the heat of the motor driver and shorten its life.

[0042] Here, the speed synchronization error is first filtered and smoothed, and then the differential term is obtained based on the differential gain and the speed synchronization error after filtering and smoothing. This can achieve low-pass filtering and reduce high-frequency oscillation.

[0043] S24, construct an adaptive fuzzy PID controller based on the proportional term, integral term and derivative term.

[0044] For example, the adaptive fuzzy PID controller is represented as ;in, These represent proportional gain, integral gain, and derivative gain, respectively. These represent the speed synchronization error and the speed synchronization error after filtering and smoothing, respectively. This represents a saturation function, used to limit the upper limit of integration.

[0045] Specifically, the proportional gain, integral gain, and derivative gain can be updated by fuzzy logic rules. For example, if the speed synchronization error is large and... If it is positive, then the proportional gain is increased.

[0046] S3, obtain the speed prediction error between the first group of silent push rod motors and the second group of silent push rod motors, and construct a predictive compensator based on the speed prediction error to compensate for sudden acceleration changes during start-stop.

[0047] Rotational speed prediction error can be predicted based on an ARIMA model or LSTM. Predictive compensators are primarily used to anticipate acceleration changes during start-up and shutdown (such as inertial shocks during bed displacement). For example, at the moment of start-up and shutdown, the gain is dynamically adjusted by predicting load changes (such as patient weight distribution) to avoid speed overshoot.

[0048] As a preferred technical solution, such as Figure 3 As shown, the specific method for constructing the predictive compensator includes the following steps: S31, obtain the error difference between the speed prediction error and the speed synchronization error, and perform a weighted summation of the error difference to obtain the error compensation value.

[0049] S32, obtain the compensation intensity coefficient used to balance predictive compensation and real-time control, and construct a predictive compensator based on the compensation intensity coefficient and the error compensation value.

[0050] For example, the predictive compensator is represented as ;in, These represent the compensation strength coefficient and the error compensation value, respectively. Indicates the first The contribution weight of each prediction time. These represent the compensation index and the prediction step size, respectively. The compensation intensity coefficient is generally between 0.1 and 0.3, with a default value of 0.2. It decreases as k increases, emphasizing near-end prediction.

[0051] Here, the proportional gain, integral gain, and derivative gain can be dynamically adjusted based on the error rate of change and the load size to avoid over-adjustment; the predictive compensator uses historical operating data to predict potential jitter (such as based on motor torque characteristics) to achieve early compensation.

[0052] Generally, standard Model Predictive Control (MPC) calculates the optimal control sequence at each step and performs rolling optimization based on actual feedback at the next time step. However, medical bed motors typically include a reducer and a lead screw, resulting in significant inertial lag. The predictive compensator calculates the error difference between the speed prediction error and the speed synchronization error. Calculating the cumulative error is beneficial for system convergence and improves control accuracy.

[0053] Compared to traditional PID, this embodiment introduces a prediction mechanism, uses historical data for training (offline learning of motor characteristics) to obtain speed prediction error, and combines fuzzy logic to deal with nonlinear loads, which is conducive to achieving synchronous start and stop of dual motors and realizing zero-delay synchronization.

[0054] S4 obtains real-time control signals based on the adaptive fuzzy PID controller and predictive compensator, and controls two sets of silent push rod motors based on the real-time control signals.

[0055] The real-time control signal Represented as Specifically, real-time control signals This can be understood as the input current or voltage of the push rod motor.

[0056] For example, when the real-time control signal is positive, the output of the first set of silent push rod motors is increased; when it is negative, the output of the second set of silent push rod motors is compensated to achieve symmetrical control.

[0057] In summary, the control method for the silent push rod auxiliary device of the medical moving bed, by constructing an adaptive fuzzy PID controller and a predictive compensator, utilizes the predictive compensator to preprocess acceleration changes during the start-stop phase and combines fuzzy logic to cope with nonlinear loads, which can eliminate response differences (such as start-stop time differences and speed fluctuations) in the operation of the dual silent push rod motors of the medical moving bed, and avoid the resulting vibration problem.

[0058] In one embodiment, the control method for the silent push rod auxiliary device of the medical mobile bed further includes the following steps: introducing a multimodal factor based on a dynamic switching control strategy according to the medical bed operation mode (lifting / translation). This extends a single PID controller into a multimodal controller.

[0059] For example, the adaptive fuzzy PID controller is represented as In lifting mode or when the speed synchronization error is greater than 0.3 mm / s, emphasis is placed on accuracy, amplification ratio gain, and multimodal factor. Set to 1.2 to ensure vertical error ≤ 0.1mm; in translation mode or >5mm / s, focus on velocity, reduce proportional gain, multimodal factor Set to 0.8 to avoid overshoot during high-speed motion and improve response speed.

[0060] The aforementioned multimodal factors employ a step-like switching mechanism without a transition process, which can easily lead to a sudden change in the total PID gain, disrupting the system's continuity. Specifically, when the medical bed switches from translation to lifting, Γ(t) jumps from 0.8 to 1.2 (the gain increases by 50% instantaneously). If a small synchronization error e(t) exists at this time, the PID controller's output u(t) will suddenly amplify, causing the drive motor to generate impact torque. For the medical bed, this could directly lead to bed vibration, or even cause the patient to experience noticeable jolting.

[0061] As a preferred technical solution, the multimodal factor .in, These are represented, in order, the transition rate coefficient, the current time, and the mode switching trigger time. This allows the multimodal factor to smoothly increase from 0.8 to 1.2, avoiding abrupt changes.

[0062] Of course, it can also be set that mode switching is only allowed when the speed synchronization error is less than a certain value, such as 0.05mm / s, to ensure that the switching is performed in a stable system state.

[0063] In one embodiment, the control method for the silent push rod auxiliary device of the medical mobile bed further includes the following steps: acquiring fault detection and compensation items for real-time detection of motor abnormalities and injection of compensation signals. .in, These represent the safety factor and the fault tolerance compensation value, respectively.

[0064] . The compensation amount is dynamically calculated based on the degree of fault. For minor anomalies (such as the actuator motor temperature being between 70 and 80°C), =0.2, the compensation amount is 20% of the normal control amount; for moderate abnormalities (such as the actuator motor temperature being 80~90℃), =0.5, while limiting the compensation time to ≤5s; serious faults (such as the push rod motor temperature being 70~80℃>90℃). =0, directly triggers safety mode, stops movement and alarms.

[0065] An embodiment of the present invention also provides a control system for a silent push rod auxiliary device for a medical mobile bed, which is used to implement the control method for the silent push rod auxiliary device for a medical mobile bed, and includes a PID controller construction module, a predictive compensator construction module, and a real-time control signal acquisition module.

[0066] like Figure 4 , Figure 5 , Figure 6 as well as Figure 6 As shown, the medical mobile bed includes an X-shaped support arm, a frame, and a bed board. One end of the X-shaped support arm 1 is hinged to the frame 6, and the other end of the X-shaped support arm 1 is hinged to the bed board. One end of the silent push rod 2 is hinged to the frame, and the other end of the silent push rod is hinged to the upper crossbar of the support arm.

[0067] Specifically, the X-shaped support arm is formed by two inclined tube frames 3 hinged together. Both ends are hinged to movable seats. One movable seat is slidably connected to the lifting upper frame 4 installed at the bottom of the bed board (sliding along the length of the bed board), and the other movable seat 7 is slidably connected to the frame. The frame is equipped with a motor mounting base, and one end of the silent push rod is hinged to the frame through the motor mounting base 5. The other end of the silent push rod is hinged to the upper crossbar of the support arm, i.e., the inclined tube frame.

[0068] The control system of the silent push rod auxiliary device for the medical mobile bed includes two sets of silent push rods. The two sets of silent push rods are symmetrically installed at a preset angle on the bed body of the medical mobile bed, and the motors of the two sets of silent push rods are used to realize the lifting and lowering of the bed board.

[0069] The PID controller construction module is used to obtain the first speed of the first group of silent push rod motors and the second speed of the second group of silent push rod motors, obtain the speed synchronization error based on the first speed and the second speed, and construct an adaptive fuzzy PID controller to cope with nonlinear disturbances caused by load changes based on the speed synchronization error.

[0070] Preferably, the PID controller construction module includes a gain coefficient acquisition unit, a proportional term acquisition unit, an integral term acquisition unit, a derivative term acquisition unit, and a PID controller construction unit.

[0071] The gain coefficient acquisition unit is used to acquire the proportional gain, integral gain, and derivative gain; the proportional term acquisition unit is used to acquire the proportional term based on the proportional gain and the speed synchronization error; the integral term acquisition unit is used to acquire the synchronization error threshold and acquire the integral term based on the integral gain and the speed synchronization error, wherein when the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to be zero.

[0072] The differential term acquisition unit is used to filter and smooth the speed synchronization error, and obtains the differential term based on the differential gain and the speed synchronization error after filtering and smoothing; the PID controller construction unit is used to construct an adaptive fuzzy PID controller based on the proportional term, integral term and differential term.

[0073] For example, the adaptive fuzzy PID controller is represented as ;in, These represent proportional gain, integral gain, and derivative gain, respectively. These represent the speed synchronization error and the speed synchronization error after filtering and smoothing, respectively. This represents a saturation function, used to limit the upper limit of integration.

[0074] The predictive compensator construction module is used to obtain the speed prediction error between the first group of silent push rod motors and the second group of silent push rod motors, and to construct a predictive compensator based on the speed prediction error to compensate for sudden acceleration changes during start-stop.

[0075] As a preferred technical solution, the predictive compensator construction module includes an error compensation value acquisition unit and a predictive compensator construction unit.

[0076] The error compensation value acquisition unit is used to obtain the error difference between the speed prediction error and the speed synchronization error, and to perform a weighted summation of the error difference to obtain the error compensation value; the predictive compensator construction unit is used to obtain the compensation intensity coefficient for balancing predictive compensation and real-time control, and to construct the predictive compensator based on the compensation intensity coefficient and the error compensation value.

[0077] For example, the predictive compensator is represented as ;in, These represent the compensation strength coefficient and the error compensation value, respectively. Indicates the first The contribution weight of each prediction time. These represent the compensation index and the prediction step size, respectively. The compensation intensity coefficient is generally between 0.1 and 0.3, with a default value of 0.2. It decreases as k increases, emphasizing near-end prediction.

[0078] Here, the proportional gain, integral gain, and derivative gain can be dynamically adjusted based on the error rate of change and the load size to avoid over-adjustment; the predictive compensator uses historical operating data to predict potential jitter (such as based on motor torque characteristics) to achieve early compensation.

[0079] The real-time control signal acquisition module is used to acquire real-time control signals based on the adaptive fuzzy PID controller and the predictive compensator, and to control two sets of silent push rod motors based on the real-time control signals.

[0080] For example, the real-time control signal Represented as Specifically, real-time control signals This can be understood as the input current or voltage of the push rod motor.

[0081] For example, when the real-time control signal is positive, the output of the first set of silent push rod motors is increased; when it is negative, the output of the second set of silent push rod motors is compensated to achieve symmetrical control.

[0082] In summary, the control system of the silent push rod auxiliary device for the medical moving bed, by constructing an adaptive fuzzy PID controller and a predictive compensator, utilizes the predictive compensator to preprocess acceleration changes during the start-stop phase and combines fuzzy logic to cope with nonlinear loads. This can eliminate response differences (such as start-stop time differences and speed fluctuations) in the operation of the dual silent push rod motors of the medical moving bed, and avoid the resulting vibration problem.

[0083] In one embodiment, the silent push rod auxiliary device for the medical mobile bed uses a silent push rod motor as the drive.

[0084] The medical transfer bed in this embodiment innovatively adopts a silent push rod motor drive system. Through dynamic balance layout and precise mechanical simulation, two sets of silent push rod motors are symmetrically installed at a specific angle at 1 / 2 of the bed's centerline (40cm apart), creating a unique progressive vertical drive structure. Initially, the motors tilt towards the foot of the bed, gradually turning to a vertical state as the push rods extend. This progressive motion trajectory, combined with the tilted installation design, optimizes the matching of the push rod extension direction with the load path, significantly reducing lateral friction. The system incorporates a shock absorption module and employs a mechanical decoupling strategy, both preserving independent operating space for the motors and achieving multiple noise reductions by disrupting the resonant frequency matching conditions.

[0085] This embodiment achieves a performance breakthrough through three core optimizations: 1. Dynamic balance of the center of gravity distribution based on mechanical simulation ensures that the center of gravity is always located at the geometric center during equipment operation, eliminating abnormal vibrations; 2. The 40cm symmetrical interval installation forms a mechanical decoupling effect, effectively suppressing resonance; 3. Combining friction trajectory optimization and vibration reduction technology, the operating noise is controlled below 30 decibels.

[0086] Actual test data shows that compared with traditional equipment, the vibration amplitude is reduced by 72%, the noise energy is reduced by 85%, and the lifting stability error is ≤0.5mm. It fully meets the stringent requirements of ICU and postoperative care scenarios for quiet operation and millimeter-level precision, providing more comfortable equipment support for the medical environment.

[0087] The medical mobile bed's silent push rod auxiliary device, supplemented by an X-shaped structure, serves as a lifting system. This embodiment addresses the core issue of unstable operation in traditional push rod motors by employing a dual silent push rod motor + X-shaped support arm collaborative system to optimize stability. Using the headboard as a reference, two sets of X-shaped support arms are symmetrically installed on the left and right sides, rigidly connected by high-strength alloy crossbars to form an anti-torsional triangular mechanical frame, distributing load pressure and suppressing offset. The two sets of silent push rod motors are hinged to the crossbars on the support arms, and a smart chip enables synchronous start / stop and speed matching of the two motors, eliminating vibrations caused by response differences. Simultaneously, a built-in high-precision gear set and shock absorption module, combined with the elastic buffer design of the support arms, absorb residual vibrations during operation. The system integrates a pressure sensor to monitor the load in real time and dynamically adjusts the output power (e.g., linearly or non-linearly increasing output power based on pressure increases, or immediately increasing power when the pressure sensor detects an increase in load to avoid motor vibration). Combined with self-lubricating bearings and limit slots to constrain non-axial displacement, the system ultimately achieves a vertical lifting trajectory error of ≤1mm, a vibration amplitude reduction of 80%, and a lifespan extension of more than 3 times. This completely solves the risks of vibration, jamming, and deformation associated with traditional solutions, providing zero-vibration, highly reliable lifting support for medical, home, and other scenarios.

[0088] In summary, the control system described in this embodiment has the following advantages: 1. Noise reduction and vibration damping Noise control: By combining a silent push rod motor, a progressive vertical drive structure, and a shock absorption module, the operating noise is reduced from 50 decibels to below 30 decibels (actual noise energy attenuation of 85%), achieving medical-grade silent standards.

[0089] Vibration suppression: By adopting a mechanical decoupling strategy and an anti-torsion triangular frame, the vibration amplitude is reduced by 72%-80%, and the vertical trajectory error is ≤0.5-1mm.

[0090] Friction optimization: Specific tilt installation (40cm interval symmetrical layout) makes the extension and retraction direction of the push rod match the load path, reducing lateral friction by up to 90%.

[0091] 2. Improved operational stability Dynamic balance control: Real-time center of gravity calibration is achieved through mechanical simulation, ensuring that the center of gravity offset during equipment operation is less than 0.3mm. Synchronization control: The dual-motor intelligent synchronization system eliminates response differences, reducing the jitter rate by 98%. Buffer design: The X-shaped support arm's elastic structure absorbs 80% of residual vibration, and the limiting slots constrain non-axial displacement. 3. Lifespan and Reliability The use of a high-strength alloy frame and self-lubricating bearings extends the equipment's lifespan by 3 times.

[0092] The anti-torsional triangular structure reduces stress concentration in key components, decreasing the risk of deformation by 95%.

[0093] 4. Application Scenarios Expansion Through breakthroughs in quiet operation and stability, the equipment noise level meets the ICU requirement of <35 decibels.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A control method for a silent push rod auxiliary device for a medical mobile bed, characterized in that, The control method for the silent push rod auxiliary device of the medical mobile bed includes the following steps: Two sets of silent push rods are symmetrically installed at a preset angle on the medical mobile bed. The two sets of silent push rod motors are used to raise and lower the bed board. The first speed of the first group of silent push rod motors and the second speed of the second group of silent push rod motors are obtained. The speed synchronization error is obtained based on the first speed and the second speed. An adaptive fuzzy PID controller is constructed based on the speed synchronization error to cope with nonlinear disturbances caused by load changes. The speed prediction error between the first group of silent push rod motors and the second group of silent push rod motors is obtained, and a predictive compensator is constructed based on the speed prediction error to compensate for sudden acceleration changes during start-stop in advance. Real-time control signals are obtained using an adaptive fuzzy PID controller and a predictive compensator, and two sets of silent push rod motors are controlled based on these real-time control signals.

2. The control method for the silent push rod auxiliary device of a medical mobile bed as described in claim 1, characterized in that, The specific method for constructing an adaptive fuzzy PID controller includes the following steps: Obtain the proportional gain, integral gain, and derivative gain; and obtain the proportional term based on the proportional gain and the speed synchronization error. Obtain the synchronization error threshold, and obtain the integral term based on the integral gain and the speed synchronization error. When the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to be zero. The speed synchronization error is filtered and smoothed, and the differential term is obtained based on the differential gain and the speed synchronization error after filtering and smoothing. An adaptive fuzzy PID controller is constructed based on the proportional, integral, and derivative terms.

3. The control method for the silent push rod auxiliary device of a medical mobile bed as described in claim 2, characterized in that, The specific method for constructing a predictive compensator includes the following steps: Obtain the error difference between the speed prediction error and the speed synchronization error, and perform a weighted summation of the error difference to obtain the error compensation value; Obtain the compensation intensity coefficients used to balance predictive compensation and real-time control, and construct a predictive compensator based on the compensation intensity coefficients and error compensation values.

4. The control method for the silent push rod auxiliary device of a medical mobile bed as described in claim 3, characterized in that, The adaptive fuzzy PID controller is represented as follows: ; in, These represent proportional gain, integral gain, and derivative gain, respectively. These represent the speed synchronization error and the speed synchronization error after filtering and smoothing, respectively. This represents a saturation function, used to limit the upper limit of integration.

5. The control method for a silent push rod auxiliary device for a medical mobile bed as described in claim 4, characterized in that, The predictive compensator is represented as ; in, These represent the compensation strength coefficient and the error compensation value, respectively. Indicates the first The contribution weight of each prediction time.

6. The control method for the silent push rod auxiliary device of a medical mobile bed as described in claim 5, characterized in that, The real-time control signal Represented as .

7. A control system for a silent push rod auxiliary device for a medical mobile bed, used to implement the control method for the silent push rod auxiliary device for a medical mobile bed as described in any one of claims 1-6, characterized in that, The control system for the silent push rod auxiliary device of the medical mobile bed includes: The PID controller construction module is used to obtain the first speed of the first group of silent push rod motors and the second speed of the second group of silent push rod motors, obtain the speed synchronization error based on the first speed and the second speed, and construct an adaptive fuzzy PID controller to cope with nonlinear disturbances caused by load changes based on the speed synchronization error. The predictive compensator construction module is used to obtain the speed prediction error between the first group of silent push rod motors and the second group of silent push rod motors, and to construct a predictive compensator based on the speed prediction error to compensate for sudden acceleration changes during start-stop in advance. The real-time control signal acquisition module is used to acquire real-time control signals based on the adaptive fuzzy PID controller and the predictive compensator, and to control two sets of silent push rod motors based on the real-time control signals.

8. The control system for a silent push rod auxiliary device for a medical mobile bed as described in claim 7, characterized in that, The PID controller construction module includes: Gain coefficient acquisition unit, used to acquire proportional gain, integral gain and derivative gain; The proportional term acquisition unit is used to acquire the proportional term based on the proportional gain and the speed synchronization error. The integral term acquisition unit is used to acquire the synchronization error threshold. It acquires the integral term based on the integral gain and the speed synchronization error. When the absolute value of the speed synchronization error is greater than the synchronization error threshold, the integral gain is forced to be zero. The differential term acquisition unit is used to filter and smooth the speed synchronization error, and to obtain the differential term based on the differential gain and the speed synchronization error after filtering and smoothing. The PID controller building unit is used to construct an adaptive fuzzy PID controller based on the proportional, integral, and derivative terms.

9. The control system for a silent push rod auxiliary device for a medical mobile bed as described in claim 8, characterized in that, The predictive compensator building block includes: The error compensation value acquisition unit is used to acquire the error difference between the speed prediction error and the speed synchronization error, and to perform a weighted summation of the error difference to obtain the error compensation value. The predictive compensator construction unit is used to obtain the compensation intensity coefficient for balancing predictive compensation and real-time control, and to construct the predictive compensator based on the compensation intensity coefficient and the error compensation value.

10. The control system for a silent push rod auxiliary device for a medical mobile bed as described in claim 9, characterized in that, The medical mobile bed includes an X-shaped support arm, a frame, and a bed board. One end of the X-shaped support arm is hinged to the frame, and the other end of the X-shaped support arm is hinged to the bed board. One end of the silent push rod is hinged to the frame, and the other end of the silent push rod is hinged to the upper crossbar of the support arm.

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