Health care displacement machine overload protection and braking method and system

Abstract

The application discloses a kind of overloading protection and braking method and system of health-care displacement machine, it is related to the field of overloading protection and braking of health-care displacement machine, it is applied to the carbon fiber health-care displacement machine of driving lifting integrated system, displacement machine uses single battery single control system architecture, lifting mechanism uses stainless steel non-standard parts, whole machine waterproof level reaches IPX3;Method first dynamic adjustment sampling frequency with operating speed, real-time acquisition displacement machine operating multidimensional state parameters, combined with driving speed, hanging tension, fuselage inclination angle identifies static hanging, lifting operation, walking displacement three types of working conditions.The application effectively solves the problem that existing fixed threshold scheme has poor adaptability, is easy to appear false trigger or protection failure, the accuracy of overload determination is greatly improved, the whole sealing design is suitable for disinfection spraying, water stain splashing environment in nursing scene, and the impact risk of traditional hard braking is avoided by grading braking strategy.

Description

Technical Field

[0001] This invention relates to the field of overload protection and braking technology for rehabilitation and transfer machines, and particularly to an overload protection and braking method and system for rehabilitation and transfer machines. Background Technology

[0002] In the current field of elderly care, the demand for bed-chair transfer, bathing relocation, and rehabilitation mobility for disabled and semi-disabled individuals continues to grow. Electric elderly care transfer machines, as core nursing equipment to replace manual handling, have been widely used in elderly care institutions, rehabilitation hospitals, and home care scenarios. The core demand for industry development is to balance the convenience of transfer operations, the comfort of the cared-for individuals, and the safety of operation in all scenarios. Among these, structural damage caused by overload, falls, and equipment slippage are key safety risks that need to be controlled.

[0003] Currently, the mainstream overload protection solutions for elderly care and mobility wards are mainly divided into two categories: The first category is mechanical overload protection solutions. The core component is a shear pin or friction plate torsion limiting mechanism integrated into the lifting transmission chain. The working principle is that when the actual load exceeds the preset rated value, the shear pin breaks under force or the friction plate slips, cutting off the power transmission path. This type of solution does not require the intervention of an electronic control unit, has a simple structure, and low cost, and is widely used in low-end and mid-range entry-level mobility ward products. However, this type of solution can only achieve rigid protection with a fixed threshold and cannot adapt to changes in load-bearing capacity under dynamic working conditions such as machine tilt, ambient temperature fluctuations, and long-term structural fatigue. The protection is triggered by an instantaneous hard cut-off, which can easily generate a large impact, causing the person being cared for to lose stability and bump into something. Moreover, after the shear pin breaks, it needs to be disassembled and replaced, resulting in high maintenance costs. After long-term use, the wear of the friction plate will cause the protection threshold to drift, and the reliability will gradually decrease with the running time. At the same time, it cannot cover the overload risk prevention and control in walking and moving scenarios.

[0004] The second type is the electronically controlled overload protection scheme. Its core principle is to indirectly determine the load size by detecting the operating current of the drive motor. When the current exceeds the factory-preset threshold, the power output of the drive unit is cut off. This type of scheme has a fast response speed, no easily damaged parts, and requires no frequent maintenance, making it the mainstream configuration for current mid-to-high-end patient transfer machines. However, this type of scheme is mostly adapted to traditional aluminum alloy bodies and dual-battery, dual-control architecture patient transfer machines. The protection threshold is a factory-fixed setting and does not consider the additional bending moment caused by body tilting, the reduction in battery discharge capacity under high and low temperatures, or the fatigue strength decay of the metal structure after long-term use. This results in poor threshold adaptability and a tendency for false triggering or protection failure. Furthermore, this type of scheme generally has a low protection level, only reaching IPX1, which cannot withstand the corrosion of water stains from disinfection sprays or bathing splashes, making it unsuitable for use in bathrooms and public disinfection scenarios. The braking trigger logic is mostly instantaneous hard locking, which can easily generate large impacts causing the person being cared for to slip. In wet and slippery environments, there is also a risk of wheel lock-up and slippage. The dual-system architecture is also prone to cross-unit synchronization errors and conflicting judgment logic, further reducing protection reliability.

[0005] The two existing overload protection solutions are unable to meet the high safety and high comfort requirements of various health and wellness care scenarios, and there is an urgent need for targeted optimization solutions to fill the technological gap. Summary of the Invention

[0006] This invention proposes an overload protection and braking method and system for a rehabilitation and transfer machine, which solves the problems mentioned in the prior art, such as poor overload protection threshold adaptability, low protection level, large braking impact, and easy logical conflict in the dual control architecture of existing rehabilitation and transfer machines.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an overload protection and braking method for a health and wellness transfer machine, applied to a carbon fiber health and wellness transfer machine equipped with an integrated drive and lifting system. The transfer machine adopts a single-battery, single-control system architecture, the lifting mechanism uses non-standard stainless steel components, and all electrical control components are sealed to achieve an IPX3 waterproof rating for the entire machine. The method includes the following steps: Multi-dimensional state parameters during the operation of the shifter are collected in real time according to a dynamic sampling frequency. The sampling frequency is dynamically adjusted with the operating speed, and the adjustment relationship satisfies: , For real-time sampling frequency, The static reference sampling frequency, The combined operating speed of the lifting and traveling mechanism. For the equipment's rated maximum operating speed, the collected status parameters should include at least the real-time torque of the lifting drive shaft, the real-time load of the walking drive wheel, the real-time tension of the lifting device's mounting point, the real-time output current of a single battery pack, the real-time tilt angle of the machine body, and the real-time operating temperature of the battery. After filtering the drive unit speed signal by moving average, the current static loading, lifting operation, and walking shifting conditions of the shifting machine are identified by combining the speed, load tension, and tilt angle parameters. Anti-shake window is set to avoid frequent changes in working conditions. Pre-store the basic overload thresholds for various operating conditions, including allowable stress of carbon fiber fuselage, rated load of stainless steel lifting mechanism, and rated output current of single battery pack. Dynamically adjust these basic thresholds based on real-time operating parameters to obtain a dynamic judgment threshold. The adjustment relationship satisfies: , This is the dynamic threshold for determining the corresponding parameter. The base threshold for the corresponding parameter, The tilt effect coefficient, For the real-time tilt angle of the fuselage, This is the temperature influence coefficient. Real-time battery temperature. The rated operating temperature of the battery. This is the structural fatigue influence coefficient. The number of cycles for the lifting mechanism is accumulated. The rated cycle life of the lifting mechanism; The system employs multi-parameter coupled logic to compare collected parameters with dynamic thresholds to determine overload events and their corresponding levels. Based on the overload level, a braking strategy is matched, and power limiting, power cut-off, mechanical locking, and graded alarm actions are executed in stages according to the overload location. In the event of severe overload, the single-battery output circuit is simultaneously cut off to prevent structural damage and personnel fall risks.

[0008] Furthermore, during the working condition identification process, the window width of the moving average filter is dynamically adjusted with the real-time sampling frequency. The higher the sampling frequency, the more sampling points the filter window contains, which completely filters out the spike pseudo signals caused by mechanical vibration and electromagnetic interference. Relying on the IPX3 sealing structure, the sensor zero drift is suppressed, and no additional dynamic zeroing is required. When the lifting drive motor speed is greater than zero, the travel drive wheel speed is zero, and the load tension of the sling is greater than the no-load threshold for 5 consecutive sampling cycles, it is determined to be a lifting operation condition; when the travel drive wheel speed is greater than zero, the lifting drive motor speed is zero, and the body tilt angle is within the horizontal safe range for 5 consecutive sampling cycles, it is determined to be a traveling displacement condition. When the speed of both the lifting drive motor and the walking drive wheel is zero and the load tension is stable for five consecutive sampling cycles, it is determined to be a static load condition. The anti-shake window duration for the condition switching is dynamically adjusted according to the current running speed. The faster the running speed, the shorter the anti-shake window, which takes into account both the anti-interference ability and the timeliness of the condition identification, and avoids the delay in protection action caused by the lag in condition determination.

[0009] Furthermore, during the dynamic threshold correction process, each influence coefficient is determined through prior calibration, among which the tilt influence coefficient... Based on the anisotropic stress characteristics of the carbon fiber fuselage, the ratio of the additional bending moment generated by the load tension per unit tilt angle to the allowable bending moment of the fuselage is determined. A larger tilt angle results in a lower threshold for determining the load tension and drive torque, preventing local stress exceeding limits in the carbon fiber frame under tilting conditions; temperature influence coefficient. Based on the temperature-discharge characteristic calibration of lithium iron phosphate batteries, the reduction ratio of the maximum allowable continuous discharge current of the battery under a unit temperature deviation is determined. The threshold for judging the battery output current is appropriately lowered under high and low temperature environments to avoid safety hazards caused by single-cell overcurrent. Structural fatigue influence coefficient is also considered. Based on the fatigue test characteristics of non-standard stainless steel lifting components, the attenuation ratio of the yield strength of stainless steel components under the corresponding unit cycle ratio is used to gradually reduce the judgment threshold of lifting torque and load tension as the cumulative number of lifting cycles increases, matching the strength attenuation law of metal components after long-term use; the modified dynamic threshold is set with upper and lower safety boundaries, the highest not exceeding the corresponding basic threshold and the lowest not lower than 60% of the basic threshold, to avoid protection false triggering or protection failure caused by abnormal threshold.

[0010] Furthermore, the overload level is divided into three independent levels, with different judgment conditions and response logic for each level: Level 1 is a slight overload, where the corresponding state parameter exceeds the dynamic threshold in the first range. At this time, mechanical braking is not triggered. First, the operator is informed through a low-frequency sound and light prompt on the control terminal that the load is close to the safe limit. At the same time, the output power of the corresponding drive unit is limited to 70% of the rated power to prevent the load from increasing further and to give the operator sufficient load adjustment space. Level 2 is moderate overload, where the corresponding state parameter exceeds the dynamic threshold in the second range. At this time, the power output of the corresponding drive unit is immediately cut off, triggering a medium-frequency audible and visual alarm. At the same time, the corresponding drive shaft is pre-locked with a low braking torque to prevent the load from continuing to increase and to avoid the impact caused by sudden locking. Level 3 is severe overload, where the proportion of the corresponding state parameters exceeding the dynamic threshold is in the third range. At this time, the power output of all drive units is immediately cut off, a high-frequency audible and visual alarm is triggered, and the DC contactor is synchronously driven to cut off the power output circuit of the single battery pack. After a set delay time, the full customized power torque is applied to lock all transmission mechanisms. The response latency for each of the three overload levels is reduced progressively, and the alarm intensity is increased progressively, balancing ease of operation with safety in extreme scenarios.

[0011] Furthermore, when executing the mechanical locking action, a gradient pressure boosting braking logic is adopted for lifting and moving operations. The braking pressure ramp-up slope is calculated based on the current operating state, and the calculation relationship satisfies... , The slope of the braking pressure climb. The equivalent rotational inertia of the drive shaft, The initial angular velocity for braking, The equivalent radius of action of the brake friction pad. The safe braking duration that the human body can tolerate; The braking pressure increases linearly to the target locking torque within a set time according to the calculated slope. The pressure control accuracy is ensured by relying on the stable friction coefficient of the non-standard stainless steel lifting parts, avoiding braking shock caused by excessive instantaneous braking force, and preventing the person being cared for from slipping due to inertia. During the pressure climb process, the angular deceleration of the drive shaft is monitored in real time. When the angular deceleration exceeds the human body's comfortable acceleration range, the pressure climb speed is appropriately slowed down. Combined with the damping characteristics of the carbon fiber body, braking vibration is attenuated, and braking stability is improved. After braking is completed, the slippage of the locking position is continuously detected at fixed intervals. When the slippage exceeds the safety threshold, the braking torque is gradually supplemented until the slippage is zero for several consecutive detection cycles, thus avoiding the risk of slippage and falling due to insufficient locking force. When a severe overload is triggered under static loading conditions, the maximum braking torque locking mechanism is directly applied without the need for gradient pressurization logic, thus preventing the loaded heavy objects from falling rapidly.

[0012] An overload protection and braking system for a rehabilitation and assisted mobility troop is provided, mounted on a carbon fiber rehabilitation and assisted mobility troop employing a single-battery, single-control system architecture. The troop is equipped with an integrated drive and lifting system and non-standard lifting components made of 304 stainless steel. All electrical control components utilize an epoxy potting and rubber ring sealing mounting structure to achieve an IPX3 waterproof rating for the entire machine. The system includes: The parameter acquisition module is used to collect data according to a dynamic sampling frequency. The system collects multi-dimensional status parameters during the operation of the shifting machine in real time. The collected parameters include at least the real-time torque of the lifting drive shaft, the real-time load of the walking drive wheel, the real-time tension of the hanger attachment point, the real-time output current of the single battery pack, the real-time tilt angle of the machine body, the real-time speed of the drive unit, and the real-time operating temperature of the battery. The raw parameters are preprocessed by hardware RC filtering and software sliding average before being transmitted to the control unit. The working condition identification module is used to analyze the pre-processed drive unit speed, tension, and tilt angle signals. By associating multiple signals, it determines the current static mounting, lifting operation, and walking shifting working condition of the shifter. During the identification process, an adaptive anti-shake window is set to avoid frequent changes in working condition. The overload determination module is used to pre-store basic overload thresholds for various operating conditions, including allowable stress of the carbon fiber fuselage, rated load of the stainless steel lifting mechanism, and rated output current of a single battery pack, and adjusts them according to a dynamic correction relationship. ; Calculate the dynamic judgment threshold under the current working condition, and use multi-parameter three-out-of-two coupling logic to compare the collected parameters with the dynamic threshold to determine the overload event and the corresponding overload level, and eliminate misjudgments caused by single sensor failure. The braking execution module is used to match the corresponding braking protection strategy according to the overload level, select the corresponding braking object according to the location of the overload, and perform power limiting, power cut-off, mechanical locking and audible and visual alarm actions in stages. When a severe overload is triggered, it synchronously drives the DC contactor to cut off the power output circuit of the single battery pack.

[0013] Furthermore, all sensors in the parameter acquisition module adopt a polyurethane epoxy potting structure. The sensor terminals are connected with aviation plugs and equipped with double-layer silicone rubber waterproof sealing rings. Waterproof and shock-absorbing pads are placed between the sensor body and the carbon fiber mounting base. All exposed wiring is wrapped with waterproof corrugated pipes. The overall protection performance meets the IPX3 waterproof rating requirements and meets the waterproof and corrosion-resistant requirements in daily care scenarios. Among them, the torque sensor adopts a flange structure and is integrated into the connection end of the stainless steel lifting drive shaft and the drive motor. It directly detects the actual torque transmitted by the drive shaft and eliminates the detection error caused by transmission backlash. The tension sensor adopts an S-shaped shear structure and is integrated into the connection node between the spreader and the lifting boom. It directly detects the actual load weight borne by the spreader and eliminates the detection deviation caused by the friction of the transmission mechanism. The current sensor adopts a Hall non-contact structure and is integrated into the output main circuit of the single battery pack. It has no direct electrical connection with the main circuit, thus avoiding the detection circuit from affecting the power supply stability of the main circuit. The tilt sensor uses a high-precision MEMS structure and is fixedly installed at the geometric center of the carbon fiber chassis. It is equipped with dual shock absorption to eliminate detection errors caused by mechanical vibration, and can accurately detect the tilt angle of the body in both the front-back and left-right directions.

[0014] Furthermore, the overload judgment module has a built-in threshold storage unit, threshold correction unit and coupling judgment unit. The threshold storage unit uses a ferroelectric non-volatile storage medium with high write life. The pre-stored basic thresholds for each working condition are individually calibrated under multiple working conditions such as full load, off-center load, tilt and extreme temperature before the equipment leaves the factory, matching the actual bearing capacity of the hardware of a single device. At the same time, it stores the calibration values ​​of each influence coefficient, the battery reduction parameters at different temperatures, and the structural fatigue reduction parameters at different cycle counts. The cumulative cycle count and fault log data stored in the power-off state will not be lost. The threshold correction unit is used to retrieve the collected tilt angle, battery temperature, and cumulative cycle count data in real time, and dynamically determine the threshold according to the factor weight corresponding to the current operating condition. The correction process strictly implements the upper and lower boundary constraints of the threshold to avoid the correction result from exceeding the hardware safety bearing range. The coupling judgment unit adopts a three-out-of-two correlation judgment logic. An overload event is only confirmed when at least two correlation parameters exceed the corresponding dynamic threshold at the same time. When a single parameter exceeds the threshold, it is judged as a fault of the corresponding sensor, which only triggers a fault prompt and does not trigger emergency braking, thus greatly reducing the probability of false braking.

[0015] Furthermore, the braking execution module includes normally closed electromagnetic braking mechanisms corresponding to the lifting drive shaft and the walking drive wheel, respectively, as well as a multi-level audible and visual alarm unit set on the waterproof control end. A DC contactor with an arc-extinguishing structure is connected in series on the power output circuit of the single battery pack, which can cut off the power supply circuit in milliseconds when there is a severe overload. The normally closed electromagnetic braking mechanism automatically locks the drive shaft by spring pressure when the power is off. The rated torque is 1.5 times the maximum rated load torque of the equipment, ensuring that the mechanism can still be reliably locked even when the single battery is completely de-energized or the control system fails, thus preventing heavy objects from falling or the equipment from slipping. The sound and light alarm unit's sound outlet is covered with an ePTFE waterproof and sound-permeable membrane, balancing waterproof performance and sound transmission efficiency. The lighting unit uses high-brightness RGB LEDs, which can correspond to different overload levels through different colors and flashing frequencies. The buzzer unit uses adaptive volume adjustment logic, which automatically adjusts the output volume according to the ambient noise, ensuring the effectiveness of the alert in different scenarios.

[0016] Furthermore, the system is also equipped with a power-on self-test unit and an operation log storage unit. After the shifter is powered on, it completes a full module self-test within 3 seconds, sequentially checking whether the voltage and temperature parameters of the single battery pack are normal, whether the zero-point output of each sensor is within a reasonable range, whether the engagement and release action of the electromagnetic braking mechanism is smooth, whether the CAN bus communication between modules is stable, and whether the light and buzzer functions of the audible and visual alarm unit are normal. When any fault is detected, the power output of the drive lifting integrated system is locked, and the corresponding fault code is displayed on the control terminal. Relying on the centralized scheduling logic of the single control system, the protection blind spots caused by cross-system synchronization errors and judgment logic conflicts under the original dual-system architecture are completely eliminated. The operation log storage unit stores each overload event, fault event, and parameter over-limit event with a timestamp in the ferroelectric memory, supporting subsequent maintenance retrieval and traceability.

[0017] Compared with existing technologies, the beneficial effects of this invention are: This invention utilizes a multi-factor coupled dynamic threshold correction technology, combining fuselage tilt status, real-time battery operating conditions, and cumulative structural service data to dynamically adjust the overload judgment threshold. Simultaneously, it employs a multi-parameter associated coupled judgment logic to determine overload events. This effectively solves the shortcomings of existing fixed threshold schemes, which cannot adapt to dynamic operating conditions and are prone to false triggering or protection failure. It significantly improves the accuracy of overload judgment and can cover overload risk prevention and control needs under various complex operating conditions such as tilt, extreme temperatures, and long-term service, ensuring the safety of equipment structure and personnel.

[0018] This invention is deeply compatible with carbon fiber body, single battery single control architecture, stainless steel lifting components, and IPX3 fully sealed electronic control design. Relying on the centralized scheduling logic of a single system, it completely eliminates the hidden dangers such as cross-unit synchronization error and decision logic conflict under the traditional dual-battery dual-system architecture. The sensors and electronic control units that meet the waterproof requirements of the entire link can resist water splashes and disinfection spray corrosion in daily care scenarios. It effectively solves the defects of existing solutions such as low protection level, limited adaptability to scenarios, and insufficient reliability of control logic. It can operate stably without the need for additional protective cover.

[0019] This invention utilizes graded overload response and gradient pressure braking technology to match differentiated protection strategies based on overload levels. It calculates the optimal braking pressure ramp rate by combining real-time operating parameters and adjusts the locking torque in a closed loop during the braking process. This effectively solves the shortcomings of traditional instantaneous hard braking, such as large impact, easy instability and slippage of the person being cared for, and easy slippage in wet and slippery scenarios. It balances the reliability of safety protection with the comfort of the transfer operation, avoiding additional harm to the person being cared for.

[0020] This invention can be directly adapted to various elderly care mobility devices equipped with integrated drive and lifting systems, and can be upgraded without making extensive changes to the existing hardware architecture. It can cover the nursing needs of all scenarios such as elderly care institutions, home care, rehabilitation hospitals, and bath centers, and can adapt to the needs of mobility devices with different load levels and application scenarios, thus having high industry promotion value. Attached Figure Description

[0021] Figure 1 This is an overall flowchart of the overload protection and braking method for the rehabilitation and transfer machine proposed in this invention; Figure 2 This is a flowchart of the working condition identification and anti-shake processing of the present invention; Figure 3 This is a flowchart of the dynamic correction process for the overload determination threshold of the present invention; Figure 4 This is a flowchart of the graded overload determination and braking response of the present invention; Figure 5 This is a flowchart illustrating the gradient boost braking lock-up execution process of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Reference Figures 1 to 5This invention discloses an overload protection and braking method for a rehabilitation and nursing care transfer machine, applied to a carbon fiber rehabilitation and nursing care transfer machine equipped with an integrated drive and lifting system. The transfer machine adopts a single-battery, single-control system architecture, which reduces redundant control units and power supply circuits compared to the traditional dual-battery, dual-system architecture, and provides sufficient installation space for a sealed and waterproof design. The lifting mechanism uses non-standard 304 stainless steel parts to replace the original non-metallic lifting components, improving the structural transmission accuracy and long-term fatigue strength. All electrical control components are sealed with silicone rubber rings and installed with epoxy potting, making the overall waterproof rating of the machine reach IPX3, which can withstand splashes of water and disinfectant sprays within a 60-degree angle range in daily care scenarios, solving the protection failure problem caused by water ingress and short circuits under the original IPX1 protection level.

[0024] The method operates according to the following logic: First, multi-dimensional state parameters during the operation of the shifter are collected in real time at a dynamic sampling frequency. The sampling frequency is dynamically adjusted according to the operating speed, and the adjustment relationship satisfies: ;in For real-time sampling frequency, As the static reference sampling frequency, in this embodiment, the static sampling frequency is... Setting it to 10Hz corresponds to the low sampling rate requirement when the shifter is stationary, which can reduce the computing power consumption and battery standby power consumption of a single control system. The combined operating speed of the shifting machine is the resultant speed value of the linear velocity in the lifting direction and the linear velocity in the walking direction, and the unit is m / s; The rated maximum operating speed of the equipment is 0.3 m / s in this embodiment, and the rated maximum lifting speed is 0.1 m / s. The higher the speed, the faster the sampling frequency. The highest sampling frequency can reach 20 Hz, which solves the defects of low-speed sampling redundancy and high-speed missed judgment due to insufficient sampling points and instantaneous overload under the traditional fixed sampling frequency.

[0025] The collected status parameters include at least the real-time torque of the lifting drive shaft, the real-time load of the walking drive wheel, the real-time tension of the sling attachment point, the real-time output current of the single battery pack, the real-time tilt angle of the machine body, and the real-time operating temperature of the battery. All parameters are transmitted within the single control system via the internal CAN bus, eliminating cross-system communication delays and solving the problem of large data synchronization errors in dual-system systems.

[0026] After the parameters are collected, the speed signal of the drive unit is filtered by moving average. Combined with the parameters of speed, load tension and tilt angle, the current working conditions of the shifter are identified as static loading, lifting operation and walking shift. During the identification process, a judgment anti-shake window is set to avoid frequent changes in working conditions caused by road bumps and mechanism vibration. Pre-store the basic overload thresholds for various operating conditions, including allowable stress of carbon fiber fuselage, rated load of stainless steel lifting mechanism, and rated output current of single battery pack. Dynamically adjust these basic thresholds based on real-time operating parameters to obtain a dynamic judgment threshold. The adjustment relationship satisfies: ; to address the shortcomings of traditional fixed thresholds that cannot adapt to tilted forces, temperature effects, and structural fatigue degradation, among which This is the dynamic threshold for determining the corresponding parameter. The base threshold for the corresponding parameter, The tilt effect coefficient, For the real-time tilt angle of the fuselage, This is the temperature influence coefficient. Real-time battery temperature. The rated operating temperature of the battery. This is the structural fatigue influence coefficient. The number of cycles for the lifting mechanism is accumulated. The rated cycle life of the lifting mechanism.

[0027] After the threshold calculation is completed, the collected parameters are compared with the dynamic threshold using multi-parameter coupling logic to determine the overload event and its corresponding level, avoiding false triggering by a single parameter. Finally, a differentiated braking strategy is matched according to the overload level, and power limiting, power cut-off, mechanical locking, and graded alarm actions are executed in stages based on the specific location of the overload. When a severe overload is determined, the single battery output circuit is simultaneously cut off, blocking the power output from the power supply head to prevent safety risks such as local stress exceeding the limit and cracking of the carbon fiber body, deformation of the stainless steel lifting mechanism, battery overcurrent and fire, and personnel falling and bumping.

[0028] This invention also discloses that during the working condition identification process, the window width of the moving average filter is dynamically adjusted according to the real-time sampling frequency. The higher the sampling frequency, the more sampling points the filter window contains. In this embodiment, the window width is 3 sampling points when the sampling frequency is 10Hz, and the window width is 5 sampling points when the sampling frequency is increased to 20Hz. This can completely filter out spike pseudo signals caused by mechanical vibration and electromagnetic interference. Relying on the IPX3 level sealing structure to isolate water vapor from the corrosion of the sensor circuit, the sensor zero point can be kept stable for a long time without the need for dynamic zeroing every time it is powered on, reducing the user's waiting time.

[0029] The specific working condition determination logic is as follows: when the speed of the lifting drive motor is greater than zero, the speed of the travel drive wheel is zero, and the load tension of the lifting device is greater than the empty hanging threshold (in this embodiment, the empty hanging threshold is set to 5 kg, corresponding to the weight of the lifting device itself), it is determined to be a lifting operation condition; when the speed of the travel drive wheel is greater than zero, the speed of the lifting drive motor is zero, and the body tilt angle is within the horizontal safety range (i.e., the front-to-back and left-to-right tilt angles are both less than 5 degrees), it is determined to be a traveling displacement condition. When the speed of both the lifting drive motor and the walking drive wheel is zero for five consecutive sampling cycles and the load tension fluctuates within 1% for three consecutive sampling cycles, it is determined to be a static load condition. The anti-shake window duration for switching operating conditions is dynamically adjusted according to the current operating speed. The faster the operating speed, the shorter the anti-shake window. In this embodiment, the anti-shake window duration is 200ms at the highest operating speed and 1s in static conditions. This balances the anti-interference capability and timely response of operating condition identification, avoids delays in protection actions caused by lag in operating condition determination, and solves the defects of slow high-speed response and easy misjudgment in static conditions under traditional fixed anti-shake windows.

[0030] This invention also discloses that during the dynamic threshold correction process, each influence coefficient is determined through prior 1:1 physical calibration, wherein the tilt influence coefficient... Based on the anisotropic stress characteristics calibration of the carbon fiber fuselage, the proportion of the additional bending moment generated by the load tension per unit tilt angle to the allowable bending moment of the carbon fiber fuselage is determined in this embodiment. The threshold for judging load tension is set at 0.02 / degree, meaning that for every 1 degree the fuselage tilts, the threshold for judging load tension and drive torque decreases by 2%. The larger the tilt angle, the lower the threshold for judging load tension and drive torque. This avoids the local stress exceeding the limit and fracture of the carbon fiber frame under tilt conditions, and solves the defect that the traditional fixed threshold does not take into account the additional bending moment of tilt, which can easily lead to fuselage damage. Temperature influence coefficient Based on the temperature-discharge characteristic calibration of lithium iron phosphate batteries, the reduction ratio of the maximum allowable continuous discharge current of the battery under a unit temperature deviation is given in this embodiment. The calibration is set at 0.008 / degree Celsius, meaning that for every 1 degree the battery temperature deviates from the rated operating temperature of 25 degrees Celsius, the battery current judgment threshold is reduced by 0.8%. Under high and low temperature environments, the battery output current judgment threshold is appropriately reduced to avoid the risk of bulging and fire caused by single battery overcurrent, and to solve the defects of poor heat dissipation and poor temperature adaptability of the original dual battery distributed arrangement. Structural fatigue influence coefficient Based on the fatigue test characteristics calibration of non-standard lifting components made of 304 stainless steel, and the corresponding reduction ratio of the yield strength of stainless steel components under a unit cycle percentage, this embodiment... The calibration is set to 0.2, meaning that when the cumulative number of lifting cycles reaches the rated cycle life, the judgment thresholds for torque and tension are reduced by 20%. As the cumulative number of lifting cycles increases, the judgment thresholds for lifting torque and load tension are gradually reduced to match the strength decay law of metal components after long-term use, thus solving the problem of protection failure caused by the irregular fatigue characteristics of the original non-metallic lifting components and the inability to accurately correct the thresholds.

[0031] To avoid over-correction of the threshold leading to abnormal protection logic, the corrected dynamic threshold is set with upper and lower safety boundaries. The maximum threshold shall not exceed the corresponding factory-calibrated base threshold, and the minimum threshold shall not be lower than 60% of the base threshold, i.e., the threshold shall be reduced by a maximum of 40%. This avoids threshold abnormalities caused by sensor signal drift and cumulative counting errors, and eliminates problems such as false triggering or failure of protection.

[0032] In this invention, the overload level is also disclosed to be divided into three independent levels. The judgment conditions and response logic of different levels are set differently according to the degree of risk: Level 1 is mild overload, and the corresponding state parameter exceeds the dynamic threshold in the first range of 0-10%. At this time, mechanical braking is not triggered. First, the operator is informed by low-frequency sound and light prompts on the control terminal that the load is close to the safe limit. The prompt frequency is 1 time / second. At the same time, the output power of the corresponding drive unit is limited to 70% of the rated power. The drive unit is prohibited from continuing to increase the output power to avoid further increase of load and give the operator sufficient time to adjust the load. Normal nursing operation will not be interrupted due to sudden braking. Level 2 is moderate overload, where the corresponding state parameter exceeds the dynamic threshold by 10%-30% in the second range. At this time, the power output of the corresponding drive unit is immediately cut off, triggering a medium-frequency audible and visual alarm at a frequency of 2 times per second. At the same time, the corresponding drive shaft is pre-locked with a low braking torque of 30% of the rated torque to prevent the load from continuing to increase and to avoid the impact of sudden locking that may startle or bump the caregiver. Level 3 is a severe overload, corresponding to a state parameter exceeding the dynamic threshold by more than 30% in the third interval. At this time, the power output of all drive units is immediately cut off, triggering a high-frequency audible and visual alarm at a frequency of 5 times per second. The DC contactor is then driven to cut off the power output circuit of the single battery pack. After a 200ms delay to allow the residual current in the power circuit to dissipate, the full customized power torque is applied to lock all transmission mechanisms to prevent arcing and damage to the contacts caused by cutting off the contactor while it is under current.

[0033] The response latency for each of the three overload levels is reduced progressively: 500ms for Level 1 overload, 200ms for Level 2 overload, and 50ms for Level 3 overload. The alarm intensity increases progressively, balancing the convenience of normal operation with the safety protection capability in extreme scenarios. This solves the shortcomings of traditional overload protection, which does not differentiate between levels, hard locks upon triggering leading to poor user experience, and slow response in high-risk scenarios.

[0034] This invention also discloses a gradient pressure boosting braking logic used for lifting and moving operations when performing mechanical locking actions. The braking pressure ramp rate is calculated based on the current operating state, and the calculation relationship satisfies: ;in The braking pressure ramp rate is expressed in N / s. The equivalent moment of inertia of the drive shaft is the total equivalent moment of inertia including the drive motor, transmission gears, drive shaft, and the mass of the load on the lifting device or traveling wheels, and the unit is kg·m². The angular velocity of the drive shaft at the initial moment of braking is expressed in rad / s. The effective radius of the friction pad of a normally closed electromagnetic brake is given in meters. To ensure a safe braking duration tolerable to the human body, this embodiment sets it to 0.5 seconds, corresponding to a comfortable range of 0.6 m / s² deceleration during braking, thus avoiding the risk of the person leaning forward or slipping due to excessive deceleration. The braking pressure increases linearly to the target locking torque within the set braking duration according to the calculated slope. Utilizing a high-precision transmission structure made of 304 stainless steel non-standard lifting components, the transmission gap is controlled within 0.1 degrees. The friction pads are made of wear-resistant copper-based powder metallurgy material, with a stable friction coefficient between 0.35 and 0.4, ensuring a pressure control accuracy error of less than 5%. This avoids braking shock caused by excessive instantaneous braking force and prevents the person being cared for from slipping due to inertia. During the pressure climb process, the angular deceleration of the drive shaft is detected in real time by the shaft end encoder. When the angular deceleration is converted into linear deceleration and exceeds the human body's comfortable acceleration range of 0.8 m / s², the pressure climb speed is appropriately slowed down. Combined with the high damping characteristics of the carbon fiber body itself, the vibration generated during the braking process is attenuated, thereby improving the stability of the braking process.

[0035] After braking is completed, the angle of the locking position is continuously detected at a fixed cycle of 100ms. When the cumulative slip exceeds the safety threshold of 1 degree, the braking torque is gradually supplemented in increments of 5% until the slip is less than 0.1 degrees in three consecutive detection cycles. This avoids the problem of insufficient locking force caused by friction plate wear and temperature rise leading to a decrease in the friction coefficient, and eliminates the risk of slippage and falling.

[0036] For severe overloads triggered under static loading conditions, the maximum braking torque locking mechanism is directly applied without the need for gradient boosting logic, ensuring locking is completed within 100ms, preventing the load from falling rapidly, and solving the defects of traditional braking logic that does not differentiate between hard braking and slow static locking, which result in large braking impact.

[0037] This invention also discloses an overload protection and braking system for a rehabilitation and transfer machine, which is mounted on a carbon fiber rehabilitation and transfer machine with a single battery and single control system architecture. The transfer machine is equipped with an integrated drive and lifting system, which integrates the walking drive controller and the lifting drive controller on the same control board, reducing the wiring length and the number of connectors. The lifting mechanism uses non-standard parts made of 304 stainless steel with a processing precision of IT7 level. All electrical control components adopt an installation structure with epoxy potting and silicone rubber ring sealing, which makes the whole machine waterproof to IPX3 level. It can adapt to the disinfection spray and water splash environment in the nursing scenario without the need for an additional waterproof cover.

[0038] The system adopts a modular design, with each functional module communicating via an internal CAN bus. Specifically, it includes a parameter acquisition module, used to acquire parameters according to the dynamic sampling frequency formula. Real-time acquisition of multi-dimensional status parameters during the operation of the shifter. The acquired parameters include at least the real-time torque of the lifting drive shaft, the real-time load of the walking drive wheel, the real-time tension of the hanger attachment point, the real-time output current of the single battery pack, the real-time tilt angle of the machine body, the real-time speed of the drive unit, and the real-time operating temperature of the battery. The raw parameters are preprocessed by hardware RC low-pass filtering and software moving average before being transmitted to the control unit to filter high-frequency electromagnetic interference. The working condition identification module is used to analyze the pre-processed drive unit speed, tension, and tilt angle signals. By associating multiple signals, it determines the current static mounting, lifting operation, and walking shifting working condition of the shifter. During the identification process, an adaptive anti-shake window is set to avoid frequent changes in working condition. The overload determination module is used to pre-store basic overload thresholds for various operating conditions, including allowable stress of the carbon fiber fuselage, rated load of the stainless steel lifting mechanism, and rated output current of a single battery pack, and corrects them according to the dynamic threshold formula: The system calculates the dynamic judgment threshold under the current operating conditions, uses a multi-parameter three-out-of-two coupling logic to compare the collected parameters with the dynamic threshold, determines the overload event and the corresponding overload level, and eliminates misjudgments caused by single sensor drift or failure; the braking execution module is used to match the corresponding braking protection strategy according to the overload level, select the corresponding braking object according to the location of the overload, and execute power limiting, power cut-off, mechanical locking, and audible and visual alarm actions in stages. When a severe overload is triggered, it synchronously drives the DC contactor to cut off the power output circuit of the single battery pack, realizing hard protection from the power supply level. It can cut off the power without relying on software control logic, avoiding protection failure caused by software overrun.

[0039] This invention also discloses that all sensors included in the parameter acquisition module adopt a polyurethane epoxy potting structure with a potting thickness of not less than 2mm, completely encapsulating the sensor circuit board and wiring solder joints. The sensor wiring terminals adopt IP67-rated aviation plugs for connection. A double-layer silicone rubber waterproof sealing ring is set between the plug and the mounting base, with the compression controlled at 25% to ensure sealing reliability. A 3mm thick butyl rubber waterproof shock-absorbing pad is set between the sensor body and the carbon fiber mounting base, which can isolate the water seepage path in the installation gap and filter the influence of mechanical vibration on the sensor. All exposed wiring is wrapped with waterproof corrugated pipe with PVC protective layer, and the two ends of the corrugated pipe are locked with waterproof cable ties. The overall protection performance meets the IPX3 waterproof rating requirements and can withstand disinfectant spray and water splashes in daily care scenarios without causing sensor short circuits or signal drift due to water ingress.

[0040] The torque sensor adopts a flange structure and is integrated into the connection end between the stainless steel lifting drive shaft and the drive motor. It is rigidly connected by flange bolts and directly detects the actual torque transmitted by the drive shaft, eliminating detection errors caused by gear backlash and transmission friction. The tension sensor adopts an S-shaped shear structure and is integrated into the connection node between the spreader and the lifting arm. It is located at the very end of the entire lifting transmission chain and directly detects the actual load weight borne by the spreader, eliminating the detection deviation caused by the friction of the transmission mechanism and the self-weight of the arm. The current sensor adopts a Hall non-contact structure and is integrated into the output main circuit of the single battery pack. It is sleeved outside the main circuit power supply copper busbar and has no direct electrical connection with the main circuit. This avoids the detection circuit from being connected in series with the main circuit and affecting the power supply stability. The current detection accuracy reaches 1%. The tilt sensor adopts a high-precision MEMS structure and is fixedly installed at the geometric center of the carbon fiber chassis. Two-stage silicone shock-absorbing pads are set at the installation position to reduce the transmission rate of mechanical vibration to less than 10%, eliminating the angle detection error caused by vibration during walking and lifting. It can accurately detect the tilt angle of the body in the front-back and left-right directions, with an angle detection resolution of 0.1 degrees.

[0041] In this invention, an overload determination module is also disclosed to have a built-in threshold storage unit, a threshold correction unit and a coupling determination unit. The threshold storage unit uses a ferroelectric non-volatile storage medium with a high write lifespan, which can withstand 10^12 writes, meeting the cumulative counting and log storage requirements throughout the device's life cycle, and will not cause damage to the storage chip due to frequent writing. The basic thresholds for each operating condition pre-stored in the storage unit are individually calibrated under multiple operating conditions, including full load, off-center load, tilt, and extreme temperatures ranging from -10 degrees Celsius to 45 degrees Celsius, before the equipment leaves the factory. This matches the actual hardware load-bearing capacity of a single device, avoiding inaccurate thresholds caused by hardware tolerances in mass production. At the same time, it stores the calibration values ​​of three influence coefficients, battery reduction parameters at different temperatures, and structural fatigue reduction parameters at different cycle counts. The cumulative number of rise and fall cycles and fault log data stored in the power-off state will not be lost, and there is no need to equip a backup battery to maintain storage.

[0042] The threshold correction unit is used to retrieve the collected tilt angle, battery temperature, and cumulative cycle count data in real time, and dynamically determine the threshold according to the factor weights corresponding to the current working condition. The weights of the tilt influence coefficient and structural fatigue influence coefficient are set to 0.7 under the lifting condition, and the weights of the tilt influence coefficient and temperature influence coefficient are set to 0.7 under the walking condition. Under the static mounting condition, the weights of the three coefficients are equal. The correction process strictly implements the upper and lower boundary constraints of the threshold to avoid the correction result from exceeding the hardware safety bearing range.

[0043] The coupling judgment unit adopts a three-out-of-two correlation judgment logic. An overload event is only confirmed when at least two correlation parameters exceed the corresponding dynamic threshold at the same time. For example, when judging lifting overload, at least two of the three parameters, lifting torque, lifting tension, and battery current, need to exceed the threshold. When a single parameter exceeds the threshold, it is judged as a fault of the corresponding sensor, which only triggers a fault prompt and does not trigger emergency braking. This greatly reduces the probability of false braking caused by damage to a single sensor or signal drift, and solves the problem of high false trigger rate of traditional single parameter judgment.

[0044] This invention also discloses a braking execution module including normally closed electromagnetic braking mechanisms corresponding to the lifting drive shaft and the walking drive wheel, and a multi-level audible and visual alarm unit set on the waterproof control end. A DC contactor with a permanent magnet arc extinguishing structure is connected in series on the power output circuit of the single battery pack. The rated current of the contact is 100A. In case of severe overload, it can cut off the power supply circuit within 10ms. The arc extinguishing structure can quickly extinguish the arc generated when cutting off a large current and avoid contact erosion.

[0045] The normally closed electromagnetic braking mechanism automatically locks the drive shaft under the pressure of the built-in compression spring when the power is off. The rated torque is 1.5 times the maximum rated load torque of the equipment, ensuring that the mechanism can still be reliably locked even in failure scenarios such as complete power failure of a single battery, software failure of the control system, or disconnection of wiring, so as to prevent heavy objects from falling or the equipment from slipping. The brake friction pads are made of wear-resistant copper-based powder metallurgy material, with a service life of more than 100,000 braking cycles.

[0046] The sound and light alarm unit's sound outlet is covered with an ePTFE waterproof and sound-permeable membrane, with a sound transmission loss of less than 3dB. This ensures sound transmission efficiency while preventing water stains and dust from entering the buzzer cavity. The lighting unit uses high-brightness RGB LEDs, which can match different safety states through red, yellow, and green light colors. During normal operation, it displays a solid green light; for a level one mild overload, it displays a slow yellow flash; for a level two moderate overload, it displays a fast orange flash; and for a level three severe overload, it displays a high-frequency red flash. The light's visibility distance is no less than 5 meters, allowing caregivers to easily identify the equipment status from any operating position. The buzzer unit uses a piezoelectric buzzer and is equipped with an integrated electret ambient noise detection microphone. The microphone surface is also covered with an ePTFE waterproof and sound-permeable membrane. It can collect ambient noise intensity in real time and automatically adjust the buzzer volume. In a quiet ward environment, the volume is controlled below 55 decibels to avoid disturbing other patients. In noisy public activity areas, the volume is automatically increased to 75 decibels to ensure that caregivers can clearly hear the prompt. This overcomes the shortcomings of traditional fixed-volume alarms, which are too harsh in quiet scenarios and ineffective in noisy scenarios.

[0047] The DC contactor connected in series in the power circuit of the single battery pack is connected to the IO port of the overload judgment module by an independent hard wire. The control signal is not transmitted through the CAN bus. When a severe overload is triggered, the contactor can be directly triggered to disconnect without software logic calculation. Even if the control software runs away or the bus communication is interrupted, the power can be reliably cut off. The failure safety protection is achieved at the hardware level. Compared with the traditional protection method that only cuts off the motor drive output through software, the reliability is greatly improved.

[0048] The wear of the friction pads in the normally closed electromagnetic braking mechanism can be automatically detected by the change in coil current during brake release. When the wear of the friction pads causes the brake gap to exceed the set threshold, the system will prompt for maintenance during the self-test phase to avoid the reduction of braking force after long-term use.

[0049] This invention also discloses a system-configured power-on self-test unit and an operation log storage unit. Relying on the centralized scheduling architecture of a single control system, it can complete the full-link functional self-test within 3 seconds after the shift machine is powered on, without waiting for the two control units to handshake and synchronize data across systems as in the traditional dual-battery dual-system architecture. The self-test process covers the following sequentially: The system monitors the open-circuit voltage, internal resistance, and real-time temperature of a single battery pack to determine if there are any undervoltage, overtemperature, or abnormal internal resistance faults. It also detects the zero-point output of all sensors to determine if the unloaded output of the tension sensor, the unloaded output of the torque sensor, the horizontal output of the tilt sensor, and the zero-current output of the current sensor are within the reasonable range specified by the factory, identifying sensor disconnection and drift faults. Finally, it detects the engagement and release of the normally closed electromagnetic brake mechanism by applying a rated voltage to the brake coil for 100ms and checking if the coil current is within the normal range, determining if the brake mechanism is stuck or has a broken coil wire. The communication frames of all nodes on the CAN bus are detected to determine whether there are frame loss or frame errors in the communication between each module; the function of the audible and visual alarm unit is tested by driving the LED to light up and the buzzer to sound for 100ms to confirm that the alarm output function is normal.

[0050] When any fault is detected during the self-test, all power outputs of the integrated lifting system are directly locked, and the corresponding fault code is displayed on the waterproof display screen at the control terminal. This prevents the equipment from operating with faults and completely eliminates protection blind spots caused by cross-system synchronization errors and judgment logic conflicts under the dual-system architecture. The operation log storage unit stores each overload event, fault event, and parameter over-limit event with a millisecond-level timestamp in the ferroelectric non-volatile memory. A single log contains all collected parameters, operating condition identification results, overload level, and execution action information at the time of the event. The log storage capacity can cover no less than one year of operating data. When the storage is full, it automatically overwrites the oldest non-critical fault log. During equipment maintenance, the logs can be exported through a dedicated waterproof debugging interface to quickly locate the cause of the fault and reduce the difficulty of operation and maintenance.

[0051] Reference Figure 1 This flowchart illustrates the overall logic of the overload protection and braking method for the elderly care transfer machine. First, the system dynamically adjusts the sampling frequency according to the machine's operating speed, collecting multi-dimensional state parameters in real-time and accurately, including drive shaft torque, load, and lifting tension. Then, the system filters the drive signals to accurately identify the current operating condition. Based on different operating conditions, the system dynamically adjusts the preset basic overload judgment threshold to a dynamic threshold that fits the current actual environment, considering factors such as machine tilt, battery temperature, and structural fatigue. Next, the system uses multi-parameter coupling logic to compare the real-time parameters with the dynamic threshold to confirm the overload event and its level. Finally, based on the assessed overload level, braking strategies such as audible and visual alarms, power cut-off, and mechanical locking are executed in stages to comprehensively ensure the operational safety of the transfer machine.

[0052] Reference Figure 2 This flowchart details the precise identification of the shifting machine's operating conditions and the signal anti-interference processing. To eliminate spikes and false signals introduced by electromagnetic interference and mechanical vibration, the system first performs a moving average filter on the speed signals of the lifting motor and the traveling drive wheels, using the average of three consecutive cycles as the valid speed signal. Next, the system determines the operating condition based on the combination of speed signals and auxiliary parameters: if the lifting motor rotates and the mounting point is under force, it is determined to be a lifting operation condition; if the traveling drive wheels rotate and the machine body is horizontal, it is determined to be a traveling shifting condition; if both are stationary and remain so for a certain period of time, it is determined to be a static mounting condition. During this determination process, the system specifically introduces a judgment anti-shake window to effectively avoid false triggering during transient changes in operating conditions.

[0053] Reference Figure 3 This flowchart illustrates how the overload judgment threshold is adaptively and dynamically adjusted according to the operating environment and equipment status. The system presets a basic threshold based on inherent properties such as the allowable stress of the carbon fiber fuselage, and then introduces three core correction factors: a fuselage tilt influence factor that calculates additional bending moment based on the fuselage tilt angle to adjust the tensile force threshold in the opposite direction; a battery temperature influence factor that matches the current reduction coefficient based on the real-time operating temperature to adapt to extreme temperature environments; and a structural fatigue influence factor that comprehensively considers the cumulative operating time of the metal structure, gradually reducing the load judgment threshold over time. Through the fusion calculation of these three factors, the system generates a dynamic overload judgment threshold in real time under the current operating conditions, significantly improving the protection reliability under extreme and long-term operating conditions.

[0054] Reference Figure 4 This flowchart illustrates the system's hierarchical identification and differentiated response mechanism for different overload levels. The system sets three independent overload level ranges. When the state parameter exceeds the dynamic threshold and falls within the mild overload range, the system does not immediately brake, but instead provides a low-frequency audible and visual warning and limits the upper limit of output power to alert the operator. When the parameter falls within the moderate overload range, the system immediately cuts off the corresponding power, issues a medium-frequency alarm, and implements pre-locking with a lower braking torque to allow for reaction time. If the parameter rapidly rises to the severe overload range, the system acts swiftly, completely cutting off the power output circuit, locking all drive shafts with maximum braking torque, sounding a high-frequency audible and visual alarm, and simultaneously cutting off the total battery output, thereby completely preventing the occurrence of a safety accident.

[0055] Reference Figure 5 This flowchart illustrates the gradient pressure braking logic employed by the system to ensure patient safety and equipment stability when performing mechanical braking. When braking is deemed necessary, the system does not instantly lock the brakes. Instead, it comprehensively considers the current operating speed of the transfer machine and the actual load weight on the sling to calculate the optimal braking pressure ramp rate for the current state. Subsequently, within a set safe timeframe, the braking pressure increases linearly according to the calculated ramp rate, smoothly transitioning until the target locking torque is reached. This flexible braking control effectively avoids violent equipment shaking caused by sudden locking, maximizing the comfort and safety of the transferred patient.

[0056] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for overload protection and braking of a rehabilitation and transfer machine, characterized in that, Includes the following steps: Multi-dimensional status parameters during the operation of the shifter are collected in real time according to a dynamically adjusted sampling frequency. The sampling frequency increases with the increase of the operating speed. The status parameters include at least the real-time torque of the lifting drive shaft, the real-time load of the walking drive wheel, the real-time tension of the lifting device mounting point, the real-time output current of the single battery pack, and the real-time tilt angle of the machine body. After filtering the drive unit's operating signal, the current operating condition of the shifter is identified, including static mounting condition, lifting operation condition, and walking shifting condition; Combining the allowable stress of the carbon fiber body, the rated load of the stainless steel lifting mechanism, and the rated output current of the single battery pack, the basic overload judgment thresholds corresponding to different working conditions are preset, and the dynamic overload judgment thresholds under the current working conditions are obtained by dynamically correcting them according to the real-time operating parameters. The system employs multi-parameter coupled logic to compare collected parameters with dynamic thresholds to determine overload events and their corresponding levels. Based on the overload level, a braking strategy is matched, and power cut-off, mechanical locking, and alarm actions are executed in stages according to the overload location. In the event of severe overload, the single-battery output circuit is simultaneously cut off to prevent structural damage and safety accidents.

2. The overload protection and braking method for the rehabilitation and transfer machine according to claim 1, characterized in that, The specific process for identifying the current operating condition of the shift machine is as follows: First, the speed signals of the lifting drive motor and the walking drive wheel are processed by moving average filtering to remove electromagnetic interference and mechanical vibration caused by spike pseudo signals during signal transmission. The average value of the signal within three consecutive sampling periods is taken as the effective speed signal. When the effective speed signal of the lifting drive motor is detected to be greater than zero and the effective speed signal of the travel drive wheel is zero, and the tension value of the load point of the lifting device is greater than the no-load threshold, it is determined to be a lifting operation condition. When the effective speed signal of the walking drive wheel is detected to be greater than zero and the effective speed signal of the lifting drive motor is zero, and the tilt angle of the machine body is within the horizontal safe range, it is determined to be a walking displacement condition. When the effective speed signals of both the lifting drive motor and the walking drive wheel are detected to be zero, and the duration reaches the set stable duration threshold, it is determined to be a static mounting condition; a judgment anti-shake window with a set width is set during the condition switching process.

3. The overload protection and braking method for the rehabilitation and transfer machine according to claim 1, characterized in that, The preset basic overload judgment thresholds corresponding to different operating conditions are dynamically adjusted based on real-time operating parameters to obtain the dynamic overload judgment threshold under the current operating condition. Specifically, a multi-factor correction model is constructed around three types of influencing factors: The first category is the fuselage tilt influencing factor. The additional bending moment of the load-bearing tension on the carbon fiber fuselage frame is calculated based on the real-time tilt angle of the fuselage. The threshold for judging the load-bearing tension is adjusted in reverse according to the ratio of the additional bending moment to the allowable bending moment of the fuselage. The larger the tilt angle, the lower the threshold for the load-bearing tension. The second category is the battery temperature influence factor, which matches the corresponding current output reduction coefficient according to the real-time operating temperature of a single battery pack, and appropriately reduces the judgment threshold of battery output current under low temperature and high temperature environments. The third category is the structural fatigue influencing factor. The fatigue reduction coefficient is calculated based on the cumulative number of lifting cycles and the cumulative load duration of the stainless steel lifting mechanism. As the cumulative running time increases, the judgment thresholds for the lifting drive shaft torque and the load tension are gradually reduced to match the fatigue strength decay characteristics of the metal structure after long-term use.

4. The overload protection and braking method for the rehabilitation and transfer machine according to claim 1, characterized in that, The overload levels are divided into three levels, and the judgment conditions and response logic for each level are set independently: Level 1 is a light overload, where the corresponding state parameter exceeds the dynamic threshold by a certain percentage within the first set range. At this time, mechanical braking is not triggered immediately. Instead, the operator is informed that the current load is approaching the upper limit through a low-frequency audible and visual warning on the control terminal. At the same time, the upper limit of the output power of the corresponding drive unit is limited. Level 2 is moderate overload, where the corresponding state parameter exceeds the dynamic threshold by a certain percentage within the second set range. At this time, the power output of the corresponding drive unit is immediately cut off, triggering a medium-frequency audible and visual alarm. At the same time, the corresponding drive shaft is pre-locked with a lower braking torque, giving the operator time to adjust the load. Level 3 is severe overload, where the corresponding state parameter exceeds the dynamic threshold by a certain percentage within the third set range. At this point, the entire circuit power is immediately cut off, all drive shafts are locked by the rated maximum braking torque, a high-frequency audible and visual alarm is triggered, and the power output circuit of the single battery pack is simultaneously cut off.

5. The overload protection and braking method for the rehabilitation and transfer machine according to claim 4, characterized in that, When performing mechanical braking and locking actions, gradient pressure boosting braking logic is adopted for lifting operation and walking and shifting operation respectively. The optimal braking pressure ramping slope is calculated based on the current operating speed and load weight. The braking pressure increases linearly to the target locking torque within a set time according to the calculated ramp.

6. An overload protection and braking system for a rehabilitation and transfer machine, mounted on a carbon fiber rehabilitation and transfer machine employing a single-battery, single-control system architecture, for implementing the overload protection and braking method for the rehabilitation and transfer machine as described in any one of claims 1-5, characterized in that, include: The parameter acquisition module is used to collect multi-dimensional status parameters of the shifter in real time according to the dynamically adjusted sampling frequency. The status parameters include at least the real-time torque of the lifting drive shaft, the real-time load of the walking drive wheel, the real-time tension of the hanger attachment point, the real-time output current of the single battery pack, the real-time tilt angle of the machine body, the real-time speed of the drive unit, and the real-time operating temperature of the battery. The collected raw parameters are pre-processed by initial filtering and then transmitted to the control unit. The working condition identification module is used to analyze the pre-processed drive unit operation signal and identify the current working condition of the shifter. The working conditions include static mounting, lifting operation, and walking shifting. An anti-shake window is set during the identification process. The overload determination module is used to pre-store the basic overload determination thresholds corresponding to different working conditions. Combined with real-time operating environment parameters, a multi-factor correction model is used to dynamically correct the basic thresholds to obtain the current dynamic determination threshold. Multi-parameter coupling logic is used to compare the collected state parameters with the dynamic thresholds to determine the overload event and the corresponding overload level. The braking execution module is used to match the corresponding braking protection strategy according to the overload level, select the corresponding braking object according to the location of the overload, and perform power cut-off, mechanical braking lock-up and alarm output actions in stages. When a severe overload is triggered, it synchronously drives the DC contactor to cut off the power output circuit of the single battery pack.

7. The overload protection and braking system for the rehabilitation and transfer machine according to claim 6, characterized in that, All sensors in the parameter acquisition module adopt an epoxy potting installation structure. The sensor wiring terminals are connected with aviation plugs and are equipped with double-layer waterproof sealing rings. Waterproof and shock-absorbing pads are installed between the sensor body and the mounting base. All exposed wiring is wrapped with waterproof corrugated pipes. The overall protection performance meets the IPX3 waterproof rating requirements. The torque sensor adopts a flange-mounted structure and is integrated into the connection end between the stainless steel lifting drive shaft and the lifting drive motor; the tension sensor adopts an S-shaped structure and is integrated into the connection node between the lifting device and the lifting arm; the current sensor adopts a Hall-type non-contact structure and is integrated into the output main circuit of the single battery pack, without direct electrical connection to the main circuit; the tilt sensor adopts a MEMS structure and is fixedly installed at the geometric center of the carbon fiber chassis.

8. The overload protection and braking system for the rehabilitation and transfer machine according to claim 6, characterized in that, The overload determination module has a built-in threshold storage unit, threshold correction unit and coupling determination unit. The threshold storage unit uses a non-volatile storage medium, which pre-stores the basic thresholds for various working conditions, such as the allowable stress of the carbon fiber fuselage, the rated load of the stainless steel lifting mechanism and the rated output current of the single battery pack. It also stores the battery current reduction coefficient corresponding to different temperatures, the structural fatigue reduction coefficient corresponding to different cycle numbers and the fuselage bending moment correction parameters corresponding to different tilt angles. The threshold correction unit is used to retrieve the stored correction parameters, combine them with the real-time collected tilt angle, battery operating temperature and cumulative running time data of the mechanism, and dynamically correct the basic threshold according to the correction factor weight under the corresponding working condition to generate the actual judgment threshold at the current moment. The threshold correction process sets the upper and lower limit boundaries. The coupling judgment unit is used to compare the collected multi-dimensional state parameters with the corrected dynamic threshold, use multi-parameter correlation judgment logic to confirm the overload event, eliminate misjudgments caused by single sensor failure or signal interference, determine the corresponding overload level according to the proportion of parameters exceeding the threshold, and transmit the level signal to the braking execution module.

9. The overload protection and braking system for the rehabilitation and transfer machine according to claim 6, characterized in that, The braking execution module includes normally closed electromagnetic braking mechanisms corresponding to the lifting drive shaft and the walking drive wheel, respectively, as well as a multi-level audible and visual alarm unit set at the control terminal. A DC contactor controlled by the overload judgment module is connected in series on the power output circuit of the single battery pack, and the power supply circuit is cut off when overload occurs.

10. The overload protection and braking system for the rehabilitation and transfer machine according to claim 9, characterized in that, The system is also equipped with a power-on self-test unit. When the shifter is powered on, it sequentially checks the communication status and functional validity of each module. When a fault is detected, it locks the power output of the drive lifting integrated system and avoids the judgment conflict caused by the redundancy of the dual system by relying on the centralized scheduling logic of the single control system.

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