Lower extremity dysfunction patient transfer assisting robot

Abstract

The present application belongs to the field of household nursing robots, and particularly relates to a lower limb dysfunction patient transfer assisting robot, which comprises a mechanical arm, a moving unit, and a lifting support mechanism, the mechanical arm is fixedly connected to the moving unit, the lifting support mechanism is connected to the mechanical arm, and a folding seat is further arranged above the moving unit; the lifting support mechanism comprises a chest supporting plate, an underarm flexible support mechanism, and a leg flexible support mechanism, the chest supporting plate is used for supporting the chest of a person to be nursed, the underarm flexible support mechanism is used for supporting the underarm of the person to be nursed, and the leg flexible support mechanism is used for supporting the thigh of the person to be nursed, the high-flexibility lifting structure of the chest supporting plate combined with the lifting support mechanism is adopted, the stability of support is ensured, the human body contour and posture change can be self-adapted, and the comfort and safety in the transfer process are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of home care robots, specifically relating to a transfer assistance robot for patients with lower limb dysfunction. Background Technology

[0002] my country now has the world's largest elderly population. As people age, their physical functions decline, particularly in lower limb mobility, leading to a decrease in their ability to care for themselves. This has increased the demand for assistive mobility products. Given this large disabled elderly population, increasing elderly care resources and improving the performance of assistive devices are urgently needed.

[0003] Existing transfer assistive robots still have many problems in clinical use, patient experience, and ease of operation: 1) Most devices use fixed support structures, which cannot adapt to the body curves of patients with different heights, body types, and limb deformities. The armpits, waist, and buttocks are the main stress points, which can easily cause a feeling of pressure. This can easily cause secondary injury to patients with osteoporosis, spinal injuries, or postoperative conditions. Some devices can even compress the chest cavity and affect breathing; 2) During the transfer process, the patient's torso is often "forcibly fixed" and cannot maintain a natural posture such as bending over or lying down. The head and legs often lack effective support, which can easily cause a feeling of being suspended or pulled. Elderly people with cognitive impairment are especially prone to fear and struggle due to physical restraint; 3) Most mainstream devices have rigid wheels without independent suspension. When encountering hospital thresholds, floor seams, carpet edges, or small slopes, they are prone to jamming, bumping, or even slipping. This not only affects the experience but may also cause the patient's body to tilt forward due to the sudden stop of the device. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a transfer assistance robot for patients with lower limb dysfunction. This robot is suitable for people with lower limb functional degeneration and meets users' needs for assistance with getting up and transferring in the home environment.

[0005] A transfer assistance robot for patients with lower limb dysfunction includes a robotic arm, a mobile unit, and a lifting support mechanism. The robotic arm is fixedly connected to the mobile unit, and the lifting support mechanism is connected to the robotic arm. A folding seat is also provided above the mobile unit. The lifting support mechanism includes a chest support plate, an underarm flexible support mechanism, and a leg flexible support mechanism. The chest support plate is fixed to the front end of the robotic arm. One end of the underarm flexible support mechanism and the leg flexible support mechanism are rotatably connected to the rear of the chest support plate. The chest support plate is used to support the chest of the person being cared for, the underarm flexible support mechanism is used to support the underarms of the person being cared for, and the leg flexible support mechanism is used to support the thighs of the person being cared for.

[0006] Furthermore, the mobile unit includes an active swing arm suspension chassis, independent drive wheels, and auxiliary support wheels. The active swing arm suspension chassis has four independent drive wheels, each equipped with an electromagnetic brake. A set of auxiliary support wheels is located behind the active swing arm suspension chassis, and the auxiliary support rod is retractably connected to the active swing arm suspension chassis. The active swing arm suspension chassis includes a vehicle chassis, which has four sets of active swing arm suspension assemblies. Each active swing arm suspension assembly includes a swing arm and a swing arm motor. One end of the swing arm is connected to the independent drive wheel, and the other end is fixed to the vehicle chassis via a bearing seat and connected to the output shaft of the swing arm motor. An equipment compartment is located within the vehicle chassis. The vehicle is equipped with a battery, power management module, navigation module, and main control system. LiDAR and ultrasonic radar are mounted on the chassis. An IMU attitude sensor and suspension travel sensor are located inside the chassis. Drive wheel speed sensors are mounted on the axles of the independent drive wheels, and an active swing arm torque sensor is mounted on the output shaft of the swing arm motor. The LiDAR, ultrasonic radar, IMU attitude sensor, suspension travel sensor, drive wheel speed sensor, and active swing arm torque sensor are electrically connected to the main control system. The main control system is connected to the navigation module and controls the movement of the swing arm motor, electromagnetic brake, auxiliary support wheel, and independent drive wheel. The battery supplies power to all electrical devices through the power management module.

[0007] Furthermore, the vehicle chassis is provided with four limiting and buffering mechanisms to limit the swing position of each swing arm. The limiting and buffering mechanism includes a limiting block and a spring. The limiting block is fixed to the side of the vehicle chassis, and a spring is provided at the bottom of the limiting block. The spring is fixed to the vehicle chassis.

[0008] Furthermore, the robotic arm includes a connecting support, a first robotic arm, and a second robotic arm. The connecting support is fixed on the moving unit, and the first robotic arm is rotatably connected above the connecting support. The first robotic arm is rotatably connected to the second robotic arm, and an assist support mechanism is fixedly connected to the front end of the second robotic arm. Displacement sensors are respectively provided on the first robotic arm and the second robotic arm. Current sensors are provided on the drive motors of the first robotic arm and the second robotic arm, and each drive motor is equipped with an encoder. The displacement sensors, current sensors, drive motors, and encoders are electrically connected to the main control system.

[0009] Furthermore, flexible pressure sensors are installed on the chest support plate, underarm flexible support mechanism, and leg flexible support mechanism of the lifting support mechanism. The chest support plate also integrates a binocular stereo vision sensor, a microphone, a speaker, and a warning light. The binocular stereo vision sensor is located on the side of the chest support plate facing the user, and the microphone, speaker, and warning light are respectively located on both sides of the chest support plate. The flexible pressure sensor and the binocular stereo vision sensor are electrically connected to the control system, and the control system is electrically connected to the microphone, speaker, and warning light.

[0010] Furthermore, the folding seat includes a folding seat support and seat plates. The folding seat support is fixed on the moving unit, and the two seat plates are rotatably connected to the folding seat support.

[0011] A method for using an assistive robot to transfer a patient with lower limb dysfunction includes the following steps: Control the transfer robot to move it to the vicinity of the person being cared for; The main control system of the mobile unit issues commands to control the electromagnetic brake to lock the independent drive wheel and extend the auxiliary support wheel; The underarm flexible support mechanism supports the underarms of the person being cared for, the leg flexible support mechanism supports the sides of the thighs, and the chest support plate works in conjunction with the underarm and leg flexible support mechanisms to support the body of the person being cared for. The underarm flexible support mechanism and the leg flexible support mechanism hold the person being cared for so that they can be moved into the mobile unit. The folding seat is opened and the person being cared for sits on the folding seat. The mobile unit moves the person being cared for to the target location. When an obstacle is encountered during the movement, the main control system controls the active swing arm to suspend the chassis and smoothly pass over the obstacle to prevent the person being cared for from hitting the chest support board.

[0012] Furthermore, the method by which the main control system controls the active rocker arm suspension chassis to smoothly traverse obstacles includes the following steps: Step 1: Obstacle pre-identification and pre-adjustment; The front-mounted lidar or ultrasonic radar detects the height and distance of obstacles in front in real time. When an obstacle of normal height is detected and the distance is less than the set threshold, the active swing arm suspension chassis automatically enters obstacle crossing mode, reduces the driving speed to an obstacle crossing idle speed of 0.1–0.2 m / s, and sets the chassis target attitude to pitch angle 0° and roll angle 0° to prepare for smooth obstacle crossing. Step 2: Single independent drive wheel contact with obstacle and active attitude compensation When any independent drive wheel contacts an obstacle and causes suspension compression, the suspension travel sensor detects the travel change in real time, and the IMU attitude sensor detects the chassis pitch and roll attitude deviations in real time. The main control system calculates the output torque of the swing arm motor of the corresponding independent drive wheel based on the travel change and chassis pitch and roll attitude errors, and outputs control commands to drive the swing arm motor of the corresponding independent drive wheel to actively twist the swing arm, raising the independent drive wheel to compensate for the sinking and counteract the chassis tilting trend. At the same time, the drive system of the four independent drive wheels dynamically distributes the drive torque of the swing arm motors according to the vertical load data monitored by the pressure sensors on each independent drive wheel, ensuring traction and preventing slippage, so that the chassis always maintains a level state. Step 3: All-wheel obstacle crossing and smooth return Once the two independent drive wheels at the front have completely passed the obstacle, the swing arm motor controls the swing arm to slowly release the force and return to the center position; when the two independent drive wheels at the rear contact the obstacle in turn, the process of step 2 is repeated; after all the independent drive wheels have passed the obstacle, the swing arm is limited by the limit buffer mechanism, the swing arm motor remains locked in safety, the moving unit resumes normal travel speed, and the entire obstacle crossing action is completed. Step 4: Extreme operating conditions and fault redundancy protection When the obstacle height exceeds the travel range, the main control system limits the maximum torsional angle of the swing arm motor and provides audible and visual alerts via microphone and warning lights; when the active swing arm suspension assembly malfunctions, the swing arm is limited by the limit buffer mechanism, and the main control system limits the travel speed of the independent drive wheels; when the IMU attitude sensor detects that the vehicle chassis pitch angle or roll attitude exceeds the safety threshold, the control system immediately activates the electromagnetic brake to lock the brake and adjusts the center of gravity back to prevent overturning.

[0013] The beneficial effects of this invention are as follows: 1. The present invention adopts a highly flexible lifting structure that combines a chest support plate with a lifting support mechanism. While ensuring stable support, it can adapt to changes in human body contour and posture, effectively avoiding local compression and body traction, and significantly improving comfort and safety during the transfer process.

[0014] 2. This invention enables synchronized and coordinated movement of multiple actuators, resulting in smooth movement, rapid response, and precise positioning. It solves the problems of asynchronous movements, large impact, and high rigidity in traditional mechanisms, thereby improving the overall flexibility and reliability of the machine.

[0015] 3. The chassis of this invention adopts a stability and obstacle-crossing scheme that combines active swing arm suspension with four-wheel independent drive. With the help of attitude closed-loop control, it can keep the chassis level when crossing thresholds or complex road conditions with uneven ground, reduce bumps and tilts, achieve seamless obstacle crossing, and greatly improve the robot's passability and riding stability.

[0016] 4. The present invention has a reasonable overall system structure, reliable control, and high safety redundancy, which can meet the high safety and high comfort requirements of medical care, elderly care and rehabilitation scenarios. It is highly practical, has a wide range of applications, and has significant promotion and application value. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the transfer assistance robot of the present invention; Figure 2 This is a schematic diagram (a) of the mobile unit structure of the transfer assistance robot of the present invention. Figure 3 This is a schematic diagram (II) of the mobile unit structure of the transfer assistance robot of the present invention; Figure 4This is a schematic diagram of the robotic arm structure of the transfer assistance robot of the present invention; Figure 5 This is a schematic diagram of the lifting support structure of the transfer assistance robot of the present invention; Figure 6 This is a schematic diagram of the folding seat of the transfer assistance robot of the present invention; Figure 7 This is a schematic diagram of the active swing arm suspension chassis structure of the transfer assistance robot of the present invention; Figure 8 This is a schematic diagram of the swing arm of the transfer assistance robot of the present invention in different swing states; Figure 9 This is a schematic diagram of the flexible robotic arm of the transfer assistance robot of the present invention; Figure 10 This is a schematic diagram illustrating the workflow of the transfer assistance robot of the present invention; In the attached diagram: 1. Robotic arm; 101. Connecting support; 102. First robotic arm; 103. Second robotic arm; 2. Moving unit; 201. Independent drive wheel; 202. Active swing arm suspension chassis; 2021. Vehicle chassis; 2022. Swing arm; 2023. Swing arm motor; 2024. Limiting block; 2025. Bearing seat; 203. Equipment compartment; 204. Auxiliary support wheel; 3. Lifting support mechanism; 301. Chest support plate; 3011. Binocular stereo vision sensor; 302. Flexible underarm support mechanism; 303. Flexible leg support mechanism; 4. Folding seat; 401. Folding seat support; 402. Seat plate. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings.

[0019] Currently, home care is the primary mode of care for disabled elderly people in my country. Therefore, the mobility assistive robot in this invention is used to assist in the relocation of various facilities and furniture (beds, chairs, wheelchairs, sofas, and toilets, etc.) within typical home environments such as bedrooms, living rooms, and bathrooms. This invention develops an intelligent mobility assistive device that meets the needs of target users, satisfying the relocation needs of users with lower limb dysfunction in their home environment.

[0020] like Figures 1-9As shown, a transfer assistance robot for patients with lower limb dysfunction includes a robotic arm 1, a mobile unit 2, and a lifting support mechanism 3. The robotic arm 1 is fixedly connected to the mobile unit 2, and the lifting support mechanism 3 is connected to the robotic arm 1. A folding seat 4 is also provided above the mobile unit 2. The lifting support mechanism 3 includes a chest support plate 301, an axillary flexible support mechanism 302, and a leg flexible support mechanism 303. The chest support plate 301 is fixed to the front end of the robotic arm 1. One end of the axillary flexible support mechanism 302 and the leg flexible support mechanism 303 are rotatably connected to the rear of the chest support plate 301. The chest support plate 301 is used to support the chest of the patient, the axillary flexible support mechanism 302 is used to support the armpits of the patient, and the leg flexible support mechanism 303 is used to support the thighs of the patient.

[0021] The transfer assistance robot of this invention mimics the posture of a person carrying another person. The support mechanism 3 conforms to the chest, abdomen, back, armpits, and thighs of the person being cared for, forming a wrap-around support. The chest support plate 301 simulates the back, and the flexible armpit support mechanism 302 and the flexible leg support mechanism 303 simulate the arms and hands. Specifically, the flexible armpit support mechanism 302 supports the armpits of the person being cared for and bends and deforms to "hug" the user, playing a role in auxiliary support and limitation. The flexible leg support mechanism 303 supports the sides of the thighs of the person being cared for. The flexible armpit support mechanism 302 and the flexible leg support mechanism 303 hug the person being cared for. The patient is moved into the mobile unit 2, and the folding seat 4 opens, allowing the patient to sit on the folding seat 4, thus providing support. The mobile unit 2 then moves the patient to their destination. This invention employs a highly flexible structure combining a chest support plate 301 with a flexible underarm support mechanism 302 and a flexible leg support mechanism 303. By combining rigid support with flexible drive, it achieves safe, smooth, and conforming support for the human body. The chest support plate 301 serves as the main support surface, providing stable, large-area, and uniform chest support, avoiding localized pressure and underarm stress, and enhancing patient comfort and safety.

[0022] This invention avoids the axillary pressure sensation of traditional axillary support transfer machines, reducing the risk of pressure sores and nerve damage. During the transfer, the patient maintains a natural sitting posture throughout, eliminating the need for significant position adjustments and avoiding additional hand strain during movement, thus preventing secondary injury. The experience, similar to being carried on someone's back, provides a more natural sense of support, reducing fear and resistance to mechanical equipment and improving psychological comfort during transfer. The highly conforming design, mimicking a person carrying another, allows for smooth transfers in various scenarios, including bed-to-wheelchair, bed-to-comfort, and bed-to-bathing facilities. It easily navigates narrow spaces without frequent adjustments to the patient's position. The lifting support mechanism adjusts the support angles and positions of its components according to the user's height and weight, adapting to different body types and eliminating the need for frequent parts replacements.

[0023] The mobile unit 2 includes an active swing arm suspension chassis 202, independent drive wheels 201, and auxiliary support wheels 204. The active swing arm suspension chassis 202 has four independent drive wheels 201, each equipped with an electromagnetic brake. A set of auxiliary support wheels 204 is located at the rear of the active swing arm suspension chassis 202, and the auxiliary support rod is retractably connected to the active swing arm suspension chassis. The active swing arm suspension chassis 202 includes a vehicle chassis 2021, which has four sets of active swing arm suspension assemblies. Each active swing arm suspension assembly includes a swing arm 2022 and a swing arm motor 2023. One end of the swing arm 2022 is connected to the independent drive wheel 201, and the other end is fixed to the vehicle chassis 2021 via a bearing seat 2025 and connected to the output shaft of the swing arm motor 2023. An equipment compartment 2 is located inside the vehicle chassis 2021. 03. The equipment compartment 203 houses the battery, power management module, navigation module, and main control system. The chassis 2021 is equipped with a lidar and ultrasonic radar. Inside the chassis 2021 are an IMU attitude sensor and a suspension travel sensor. The axle of the independent drive wheel 201 is equipped with a drive wheel speed sensor and a pressure sensor. The output shaft of the rocker arm motor 2023 is equipped with an active rocker arm torque sensor. The lidar, ultrasonic radar, IMU attitude sensor, suspension travel sensor, drive wheel speed sensor, pressure sensor, and active rocker arm torque sensor are electrically connected to the main control system. The main control system is connected to the navigation module and controls the movement of the rocker arm motor 2023, electromagnetic brake, auxiliary support wheel 204, and independent drive wheel 201. The battery supplies power to all electrical equipment through the power management module.

[0024] The vehicle chassis 2021 is provided with four limiting buffer mechanisms to limit the swing position of each swing arm 2022. The limiting buffer mechanism includes a limiting block 2024 and a spring. The limiting block 2024 is fixed to the side of the vehicle chassis 2021, and the bottom of the limiting block 2024 is provided with a spring, which is fixed to the vehicle chassis 2021.

[0025] In this embodiment, the moving unit 2 is used to move the person being cared for. Its four independent drive wheels 201 are independently driven, and the four sets of swing arms 2022 actively twist to ensure that the vehicle body always remains horizontal and stable. The swing arm motor 2023 drives the swing arms 2022 to rotate around the bearing seat 2025. The swing arms 2022 drive the independent drive wheels 201 to move. The independent drive wheels 201 and the vehicle chassis 2021 generate relative movement, thereby realizing the change of the height of the vehicle chassis 2021 relative to the ground. The swing arm motor 2023 is in the form of a frameless torque motor or an electric push rod, etc. The chassis 2021 is equipped with a limiting and buffering mechanism for each set of independent drive wheels. When the swing arm motor 2023 malfunctions or has insufficient power, the swing arm motor 2023 is released, and the swing arm 2022 is limited to a fixed position by the limiting and buffering mechanism. The limiting and buffering mechanism includes a spring, which can play a certain degree of buffering role. In this way, the position of the four independent drive wheels 201 is fixed, and it does not have the ability to actively adjust the height. The suspension becomes a passive mode. This can limit the position of the swing arm and thus limit the position of the independent drive wheels, changing the active swing arm suspension to a passive swing arm suspension, ensuring the safety of equipment operation. The laser radar is used to pre-detect obstacles ahead (sills, ground seams, protrusions) and identify the height of the obstacles (15). The system triggers obstacle-crossing mode when the distance is -30mm; it scans the surrounding environment to assist the vehicle chassis in omnidirectional movement to avoid collisions with walls and nursing facilities; it provides feedback on obstacle position data to provide a basis for pre-compensation of the active swing arm suspension components; ultrasonic radar assists lidar in detecting obstacles at close range (≤1m) to avoid blind spots; it detects the distance between the vehicle chassis and the hospital bed, wheelchair, and wall to assist in precise alignment (such as alignment with the hospital bed during transfer); during obstacle crossing, it monitors the distance between the independent drive wheels and the obstacle in real time and adjusts the movement speed to avoid impact; the IMU attitude sensor is used to collect vehicle chassis attitude data (pitch angle, roll angle, roll angle) in real time, sets the target attitude to 0°, and realizes attitude closed-loop control; feedback The vehicle chassis tilt error is compensated by the active swing arm suspension assembly to ensure chassis levelness during obstacle crossing; the vehicle chassis center of gravity shift is monitored, triggering a rollover warning and assisting in torque distribution to the four independent drive wheels; suspension travel sensors are used to detect the vehicle chassis suspension extension and contraction travel in real time, providing feedback on wheel sinking / lifting; in conjunction with IMU attitude sensors, the required torsional angle of the swing arm is calculated, and an attitude fusion algorithm based on extended Kalman filtering is built-in to effectively suppress the impact of dynamic disturbances on attitude accuracy, ensuring the stability of attitude accuracy and achieving active suspension compensation; abnormal swing arm suspension travel (such as jamming or overtravel) is detected, triggering a fault warning and switching to passive suspension mode; wheel speed sensors on the independent drive wheels are used to collect data from each vehicle... The robot's wheel speed is controlled synchronously to prevent it from veering off course when crossing obstacles. Wheel slippage (a sudden increase in speed but no change in displacement) is detected, triggering anti-slip control and adjusting the drive torque. The chassis speed is calculated, automatically decreasing to idle speed when crossing obstacles and returning to normal speed afterward. Data from lidar, ultrasonic radar, IMU attitude sensors, suspension travel sensors, wheel speed sensors, pressure sensors, and active swing arm torque sensors are transmitted to the main control system. The main control system uses this data to control the swing arm motor, electromagnetic brake, auxiliary support wheel, and independent drive wheel, thereby adjusting the motion state of the independent drive wheel and auxiliary support wheel. The robot is equipped with a navigation module, enabling autonomous navigation in indoor environments and path storage.

[0026] The mobile robot of this invention employs a four-wheel independent drive wheel 201 and an active swing arm suspension chassis 202 to achieve smooth obstacle crossing without a bumpy feeling, while retaining omnidirectional movement and safety redundancy. The four-wheel independent drive system enables the robot to move straight, turn, and turn around on the spot by independently driving the four wheels. The drive wheels can be made of various forms such as wheels, Mecanum wheels, and tracks. Each independent drive wheel 201 integrates an independent electromagnetic brake, which can lock synchronously when parked to avoid slipping on slopes or smooth surfaces, making it especially suitable for slippery scenarios such as kitchens and bathrooms. Through the feedback of the rotational speed of each wheel, the system can identify differences in ground slope and friction coefficient, and automatically adjust the driving force, enabling stable operation on different surfaces such as hospital floor tiles and home carpets. The independent suspension ensures that all four wheels are in contact with the ground, preventing slippage during driving and making braking more stable. The active swing arm suspension chassis 202 can dynamically adjust the suspension travel according to the height of the obstacle, adapting to different scenarios and ensuring that the transfer assistance robot can easily pass through environments such as thresholds, tile gaps, gentle slopes, and small steps. It can maintain a level position on slopes, single-sided potholes, and slanted thresholds. This structure actively stabilizes the vehicle body, achieving zero chassis pitch and completely solving the problem of tilting up / down when crossing bumps, so that users do not experience weightlessness or impact.

[0027] Two sets of fixed brackets are provided behind the chest support plate 301. Each set of fixed brackets has a rotating shaft rotatably connected to it. One rotating shaft is fixedly connected to an underarm flexible support mechanism 302, and the other rotating shaft is fixedly connected to a leg flexible support mechanism 303. The rotating shaft connected to the underarm flexible support mechanism 302 is rotatably connected to the robotic arm 1. Both rotating shafts are connected to drive motors, which are connected to the main control system. The underarm flexible support mechanism 302 includes flexible robotic arm I and flexible robotic arm II; the leg flexible support mechanism 303 includes flexible robotic arm III and flexible robotic arm IV. Flexible robotic arms I, II, III, and IV are existing structures, such as... Figure 9 As shown, flexible robotic arms can be powered, rope-driven, pneumatic, or other forms, and can bend and move in any controlled direction. The design of flexible robotic arms is inspired by the flexible structures in animal organs, such as elephant trunks and octopus tentacles. These structures lack a distinct rigid skeleton, unlike traditional rigid robots. Flexible robotic arms do not contain discrete joints or rigid links, exhibiting flexible movement, smooth deformation, and high redundant degrees of freedom. They can bend and move in any direction in space. Therefore, continuous robotic arms possess excellent bending performance, good compliance and adaptability, and safe human-robot interaction, making them promising for applications in complex, unstructured environments.

[0028] The robotic arm 1 includes a connecting support 101, a first robotic arm 102, and a second robotic arm 103. The connecting support 101 is fixed on the moving unit 2. The first robotic arm 102 is rotatably connected above the connecting support 101. The second robotic arm 103 is rotatably connected to the first robotic arm 102. The front end of the second robotic arm 103 is fixedly connected to a lifting support mechanism 3. The movement of the robotic arm 1 is a composite movement composed of the coordinated movement of multiple independent motion axes, which can simulate the action of a person carrying another person. The first robotic arm 102, the second robotic arm 103, and the lifting support mechanism 3 together constitute a three-axis robotic arm. Each drive axis can move independently under its own drive mechanism. The movement of the lifting support mechanism in interaction with the user is actually a composite movement of the three-axis robotic arm.

[0029] The first robotic arm 102 and the second robotic arm 103 are respectively equipped with displacement sensors. The drive motors of the first robotic arm 102 and the second robotic arm 103 are equipped with current sensors, and each drive motor is equipped with an encoder. The displacement sensors, current sensors, drive motors, and encoders are electrically connected to the main control system.

[0030] In this embodiment, position sensors are used to collect the displacement of each robotic arm in real time and feed it back to the main control system to achieve multi-drive synchronous control; accurately locate the position of each robotic arm to ensure that the lifting height and posture meet the preset requirements; detect whether the robotic arm will malfunction (such as jamming or overtravel) and trigger fault warning and emergency reset; encoders on the drive motors are used to collect the speed and angle of the drive mechanism motors, calculate the movement speed and displacement of the robotic arms, and achieve speed closed-loop control; monitor the operating status of the drive motors to avoid overload and overspeed, and protect the drive motors; assist position sensors to achieve dual displacement verification and improve control accuracy; current sensors are set on the drive motors to detect the operating current of each drive motor, determine the load of the robotic arm, and achieve adaptive load adjustment; monitor current abnormalities (such as short circuit or overload) to trigger motor protection and emergency shutdown; feed back current data to assist the control system in optimizing the distribution of driving force and avoiding impact from the movement of the drive mechanism; the data information monitored by the displacement sensors and current sensors is transmitted to the main control system, and the main control system controls the drive motors to work, thereby achieving independent control of the first robotic arm 102 and the second robotic arm 103.

[0031] Flexible pressure sensors are installed on the chest support plate 301, the underarm flexible support mechanism 302, and the leg flexible support mechanism 303 of the lifting support mechanism 3. The chest support plate 301 also integrates a binocular stereo vision sensor 3011, a microphone, a speaker, and a warning light. The binocular stereo vision sensor 3011 is located on the side of the chest support plate 301 facing the user. The microphone, speaker, and warning light are respectively located on both sides of the chest support plate 301. The flexible pressure sensor and the binocular stereo vision sensor 3011 are electrically connected to the control system. The control system is electrically connected to the microphone, speaker, and warning light.

[0032] In this embodiment, a flexible pressure sensor is used to detect the force distribution on various parts of the person being cared for in real time during the lifting process, avoiding excessive local pressure (such as under the armpit or chest) that could cause compression injuries; it provides feedback on force data to assist the robotic arm in adjusting its posture to achieve uniform force distribution; it detects whether the person being cared for shows a tendency to slip (sudden change in force) and triggers an anti-drop warning; a binocular stereo vision sensor is used to detect the person's body posture (pitch, tilt) in real time to prevent the patient from unconsciously swaying or tilting during the lifting process; it provides feedback on the person's posture data, and links the robotic arm and the lifting support mechanism to automatically adjust the lifting angle to prevent the patient from slipping or twisting their torso; it identifies abnormal postures of the person being cared for (such as sudden forward leaning) and triggers an audible and visual alarm and emergency braking; a microphone and speaker enable voice interaction, and it also has a local processing unit and communication device for remote interaction and intelligent algorithm implementation.

[0033] The folding seat 4 includes a folding seat support 401 and seat plates 402. The folding seat support 401 is fixed on the moving unit 2, and the two seat plates 402 are rotatably connected to the folding seat support 401.

[0034] An emergency stop button and auxiliary sensor are installed on the robotic arm of a transfer assistive robot for patients with lower limb dysfunction. The emergency stop button (with signal feedback) immediately cuts off the power supply and stops all movements in an emergency, protecting the patient and operator. It also provides feedback of the emergency stop signal, and the control system records the fault for easy troubleshooting. It complies with medical safety standards and achieves multiple redundancy protections.

[0035] Auxiliary sensors include power sensors, temperature sensors, etc.; the power sensor is electrically connected to the battery to detect the battery power, voltage, and current in real time, provide feedback on the remaining power, and remind the user to charge; it also monitors power supply abnormalities (such as overvoltage, undervoltage, and overcurrent) to trigger power protection and prevent damage to core components, thereby assisting the control system in optimizing power consumption and extending battery life. Temperature sensors monitor the temperature of core components in real time to prevent overheating damage; when the temperature exceeds the threshold, cooling measures (such as load reduction or shutdown) are triggered, and audible and visual alerts are provided. Component temperature data is recorded to assist in fault diagnosis and lifespan assessment.

[0036] The transfer-assisted robot is equipped with a voice recognition model, which can autonomously navigate to a designated location, such as a bed or toilet, based on voice commands. It can also adjust its posture based on simple voice commands to facilitate user seating and enable users to transfer to another vehicle without supervision.

[0037] like Figure 10 As shown, a method for using a transfer assistive robot for patients with lower limb dysfunction includes the following steps: The transfer assistance robot can be moved to the vicinity of the person being cared for using various methods such as voice control, mobile phone remote control, and wired remote control. The main control system of the mobile unit 2 issues a command to control the electromagnetic brake to lock the independent drive wheel 201 and extend the auxiliary support wheel 204 to ensure stability during operation. The underarm flexible support mechanism 302 supports the underarms of the person being cared for, and the leg flexible support mechanism 303 supports the side of the thigh. The chest support plate 301 works in conjunction with the underarm flexible support mechanism 302 and the leg flexible support mechanism 303 to support the body of the person being cared for, simulating the posture of a person carrying another person. The underarm flexible support mechanism 302 and the leg flexible support mechanism 303 hold the person being cared for so that the person being cared for moves into the mobile unit 2, the folding seat 4 opens, and the person being cared for sits on the folding seat 4; The mobile unit 2 moves the person being cared for to the target location. When an obstacle is encountered during the movement, the main control system controls the active swing arm to suspend the chassis and smoothly pass over the obstacle to prevent the person being cared for from hitting the chest support board.

[0038] The method for the main control system to control the active swing arm suspension chassis to smoothly pass over obstacles includes the following steps: Step 1: Obstacle pre-identification and pre-adjustment; The front-mounted lidar or ultrasonic radar detects the height and distance of obstacles in front in real time. When an obstacle of normal height is detected and the distance is less than a set threshold, the active swing arm suspension chassis 202 automatically enters obstacle crossing mode, reduces the driving speed to an obstacle crossing idle speed of 0.1–0.2 m / s, and sets the chassis target attitude to pitch angle 0° and roll angle 0° to prepare for smooth obstacle crossing. Step 2: Single independent drive wheel contact with obstacle and active attitude compensation When any independent drive wheel 201 contacts an obstacle and generates suspension compression, the suspension travel sensor detects the travel change in real time, including the travel error Δz and the travel change rate Δż; the IMU attitude sensor detects the chassis pitch attitude deviation Δ in real time. θ Lateral tilt attitude deviation Δ φ Pitch attitude deviation Lateral attitude deviation , θ des , φ des For the target attitude angle, θ IMU , φ IMUThe attitude angle is acquired by the IMU attitude sensor; based on the travel change and chassis pitch and roll attitude errors, the main control system calculates the output torque of the rocker arm motor 2023 corresponding to the independent drive wheel 201 and outputs control commands to drive the rocker arm motor 2023 of the corresponding independent drive wheel 201 to actively twist the rocker arm 2022, raising the independent drive wheel 201 to compensate for the sinking and counteract the chassis tilting trend; the formula for calculating the output torque of the rocker arm motor 2023 is as follows: , τ act τ is the output torque of the rocker motor, Δz is the suspension travel error, and τ is the torque of the rocker motor. ff The load and attitude feedforward torque of the oscillating arm motor. K p proportionality coefficient ，K d The damping coefficient, K p , K d It can be dynamically adjusted according to the load size and obstacle crossing scenario; at the same time, the drive system of the four independent drive wheels 201 dynamically distributes the drive torque of the swing arm motor 2023 according to the vertical load data monitored by the pressure sensors on each independent drive wheel 201. The specific calculation formula is as follows: Ti is the target driving torque of the i-th independent drive wheel; T base The base drive torque is calculated based on the obstacle-crossing load; F zi F is the vertical load of the i-th independent drive wheel; zsum The total vertical load of the four independent drive wheels is Fzi. When an independent drive wheel is suspended in the air, Fzi approaches 0 and Ti automatically drops to the minimum to prevent the independent drive wheel from spinning. When the independent drive wheel is on the ground, Fzi increases and Ti increases synchronously to ensure sufficient traction, so as to overcome obstacles without slipping or wheel swinging, and keep the chassis in a horizontal state at all times. Step 3: All-wheel obstacle crossing and smooth return After the two independent drive wheels 201 in front have completely passed the obstacle, the swing arm motor 2023 controls the swing arm 2022 to slowly unload the force and return to the center position; when the two independent drive wheels 201 in the rear contact the obstacle in turn, the process of step 2 is repeated; after all the independent drive wheels 201 have passed the obstacle, the swing arm 2022 is limited by the limit buffer mechanism, the swing arm motor is kept in a safe lock, the moving unit 2 resumes normal driving speed, and the entire obstacle crossing action is completed; Step 4: Extreme operating conditions and fault redundancy protection When the obstacle height exceeds the travel range, the main control system limits the maximum torsional angle of the swing arm motor 2023 and provides audible and visual alerts via microphone and warning lights. When the active swing arm suspension assembly malfunctions, the swing arm 2022 is limited by the limit buffer mechanism, meaning the main control system immediately switches to passive swing arm suspension mode. At this time, the swing arm motor is released, and the swing arm is limited and buffered by the limit buffer mechanism, the suspension becomes passive, and the travel speed is limited to ensure basic passability and safety. When the IMU attitude sensor detects that the vehicle chassis pitch angle or roll attitude exceeds the safety threshold, the control system immediately activates the electromagnetic brake to lock the brake and adjusts the center of gravity back to prevent overturning.

[0039] This invention employs a multi-axis robotic arm to achieve the main assistive lifting function. The multi-axis structure enables combined lifting, pitching, and telescopic movements, replicating the natural trajectory of a person carrying another, avoiding torso twisting and shearing forces on the patient. The multi-axis structure supports interpolation motion and velocity closed-loop, resulting in smoother operation at low speeds and adapting to zero-feel transfer for the user. Micro-angle / micro-displacement compensation can match the height differences and horizontal deviations of beds, toilets, seats, and wheelchairs, achieving higher alignment accuracy and allowing for single-person docking. Frameless torque motors or electric push rods are used for drive, enabling collision detection, torque limiting, and obstacle detection and retraction to prevent pinching and squeezing, meeting electrical safety requirements. Multi-axis linkage adjusts the posture in real time, optimizing the overall center of gravity and improving anti-tipping stability under heavy loads and large swing angles, thus enhancing overall safety. The multi-axis structure allows for one arm type to cover scenarios such as bed-wheelchair, bed-toilet / bathroom, and wheelchair, reducing parts replacement and increasing equipment utilization. Multi-axis structures can distribute the stress on the equipment, reduce the load on a single joint, and achieve lightweight and high rigidity under the same load-bearing capacity, thereby improving lifespan and portability.

[0040] The multi-electric actuator collaborative control architecture of this invention combines multi-axis synchronous control, position-torque dual closed loop, feedforward compensation + PID coupling algorithm to achieve high-precision synchronous extension and contraction, smooth start and stop, and load adaptive adjustment of the multi-actuator mechanism. It effectively solves the problems of asynchronous operation, easy jamming, and large impact of traditional multi-actuator mechanisms. At the same time, it has a complete fault diagnosis and overload protection mechanism to ensure stable operation under large load and variable load conditions.

Claims

1. A transfer assistance robot for patients with lower limb dysfunction, characterized in that, It includes a robotic arm, a mobile unit, and a lifting support mechanism. The robotic arm is fixedly connected to the mobile unit, and the lifting support mechanism is connected to the robotic arm. A folding seat is also provided on top of the mobile unit. The lifting support mechanism includes a chest support plate, an underarm flexible support mechanism, and a leg flexible support mechanism. The chest support plate is fixed to the front end of the robotic arm. One end of the underarm flexible support mechanism and the leg flexible support mechanism are rotatably connected to the rear of the chest support plate. The chest support plate is used to support the chest of the person being cared for, the underarm flexible support mechanism is used to support the underarms of the person being cared for, and the leg flexible support mechanism is used to support the thighs of the person being cared for.

2. The assistive robot for transferring patients with lower limb dysfunction according to claim 1, characterized in that, The mobile unit includes an active swing arm suspension chassis, independent drive wheels, and auxiliary support wheels. The active swing arm suspension chassis has four independent drive wheels, each equipped with an electromagnetic brake. A set of auxiliary support wheels is located behind the active swing arm suspension chassis, and the auxiliary support rod is retractably connected to the active swing arm suspension chassis. The active swing arm suspension chassis includes a vehicle chassis, which has four sets of active swing arm suspension assemblies. Each active swing arm suspension assembly includes a swing arm and a swing arm motor. One end of the swing arm is connected to the independent drive wheel, and the other end is fixed to the vehicle chassis via a bearing seat and connected to the output shaft of the swing arm motor. An equipment compartment is located within the vehicle chassis, and the equipment compartment is equipped with... The system includes a battery, power management module, navigation module, and main control system. The vehicle chassis is equipped with lidar and ultrasonic radar. Inside the chassis are IMU attitude sensors and suspension travel sensors. Drive wheel speed sensors are located on the axles of the independent drive wheels, and active swing arm torque sensors are located on the output shafts of the swing arm motors. The lidar, ultrasonic radar, IMU attitude sensors, suspension travel sensors, drive wheel speed sensors, and active swing arm torque sensors are electrically connected to the main control system. The main control system is connected to the navigation module and controls the movement of the swing arm motor, electromagnetic brake, auxiliary support wheels, and independent drive wheels. The battery supplies power to all electrical devices through the power management module.

3. The assistive robot for transferring patients with lower limb dysfunction according to claim 2, characterized in that, The vehicle chassis is equipped with four limiting and buffering mechanisms to limit the swing position of each swing arm. The limiting and buffering mechanism includes a limiting block and a spring. The limiting block is fixed to the side of the vehicle chassis, and the bottom of the limiting block is equipped with a spring, which is fixed to the vehicle chassis.

4. The assistive robot for transferring patients with lower limb dysfunction according to claim 1, characterized in that, The robotic arm includes a connecting support, a first robotic arm, and a second robotic arm. The connecting support is fixed to the moving unit, and the first robotic arm is rotatably connected to the top of the connecting support. The first robotic arm is rotatably connected to the second robotic arm, and an assist support mechanism is fixedly connected to the front end of the second robotic arm. The first and second robotic arms are respectively equipped with displacement sensors, and the drive motors of the first and second robotic arms are equipped with current sensors. Both drive motors are equipped with encoders. The displacement sensors, current sensors, drive motors, and encoders are electrically connected to the main control system.

5. The assistive robot for transferring patients with lower limb dysfunction according to claim 1, characterized in that, Flexible pressure sensors are installed on the chest support plate, underarm flexible support mechanism, and leg flexible support mechanism of the lifting support mechanism. The chest support plate also integrates a binocular stereo vision sensor, a microphone, a speaker, and a warning light. The binocular stereo vision sensor is located on the side of the chest support plate facing the user, and the microphone, speaker, and warning light are respectively located on both sides of the chest support plate. The flexible pressure sensor and the binocular stereo vision sensor are electrically connected to the control system, and the control system is electrically connected to the microphone, speaker, and warning light.

6. The assistive robot for transferring patients with lower limb dysfunction according to claim 1, characterized in that, The folding seat includes a folding seat support and seat plates. The folding seat support is fixed on the moving unit, and the two seat plates are rotatably connected to the folding seat support.

7. A method of using a transfer assistive robot for patients with lower limb dysfunction, based on the transfer assistive robot for patients with lower limb dysfunction as described in claim 1, characterized in that, Includes the following steps: Control the transfer robot to move it to the vicinity of the person being cared for; The main control system of the mobile unit issues commands to control the electromagnetic brake to lock the independent drive wheel and extend the auxiliary support wheel; The underarm flexible support mechanism supports the underarms of the person being cared for, the leg flexible support mechanism supports the sides of the thighs, and the chest support plate works in conjunction with the underarm and leg flexible support mechanisms to support the body of the person being cared for. The underarm flexible support mechanism and the leg flexible support mechanism hold the person being cared for so that they can be moved into the mobile unit. The folding seat is opened and the person being cared for sits on the folding seat. The mobile unit moves the person being cared for to the target location. When an obstacle is encountered during the movement, the main control system controls the active swing arm to suspend the chassis and smoothly pass over the obstacle to prevent the person being cared for from hitting the chest support board.

8. The method of using the assistive robot for transferring patients with lower limb dysfunction according to claim 7, characterized in that, The method for the main control system to control the active swing arm suspension chassis to smoothly pass over obstacles includes the following steps: Step 1: Obstacle pre-identification and pre-adjustment; The front-mounted lidar or ultrasonic radar detects the height and distance of obstacles in front in real time. When an obstacle of normal height is detected and the distance is less than the set threshold, the active swing arm suspension chassis automatically enters obstacle crossing mode, reduces the driving speed to an obstacle crossing idle speed of 0.1–0.2 m / s, and sets the chassis target attitude to pitch angle 0° and roll angle 0° to prepare for smooth obstacle crossing. Step 2: Single independent drive wheel contact with obstacle and active attitude compensation When any independent drive wheel contacts an obstacle and causes suspension compression, the suspension travel sensor detects the travel change in real time, and the IMU attitude sensor detects the chassis pitch and roll attitude deviations in real time. The main control system calculates the output torque of the swing arm motor of the corresponding independent drive wheel based on the travel change and chassis pitch and roll attitude errors, and outputs control commands to drive the swing arm motor of the corresponding independent drive wheel to actively twist the swing arm, raising the independent drive wheel to compensate for the sinking and counteract the chassis tilting trend. At the same time, the drive system of the four independent drive wheels dynamically distributes the drive torque of the swing arm motors according to the vertical load data monitored by the pressure sensors on each independent drive wheel, ensuring traction and preventing slippage, so that the chassis always maintains a level state. Step 3: All-wheel obstacle crossing and smooth return Once the two independent drive wheels at the front have completely passed the obstacle, the swing arm motor controls the swing arm to slowly release the force and return to the center position; when the two independent drive wheels at the rear contact the obstacle in turn, the process of step 2 is repeated; after all the independent drive wheels have passed the obstacle, the swing arm is limited by the limit buffer mechanism, the swing arm motor remains locked in safety, the moving unit resumes normal travel speed, and the entire obstacle crossing action is completed. Step 4: Extreme operating conditions and fault redundancy protection When the obstacle height exceeds the travel range, the main control system limits the maximum torsional angle of the swing arm motor and provides audible and visual alerts via microphone and warning lights; when the active swing arm suspension assembly malfunctions, the swing arm is limited by the limit buffer mechanism, and the main control system limits the travel speed of the independent drive wheels; when the IMU attitude sensor detects that the vehicle chassis pitch angle or roll attitude exceeds the safety threshold, the control system immediately activates the electromagnetic brake to lock the brake and adjusts the center of gravity back to prevent overturning.

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