Dual-arm transfer nursing robot lower limb device for multiple nursing tasks

Abstract

The application discloses a double-arm transfer nursing robot lower limb device for multiple nursing tasks, which comprises a body up-down adjusting mechanism, a chassis separation driving mechanism and a separable chassis mechanism; the body up-down adjusting mechanism is used for adjusting the height of the robot; the separable chassis mechanism comprises a left chassis module and a right chassis module; under the action of the chassis separation driving mechanism, the left chassis module and the right chassis module can approach or move away from each other, so as to adjust the size of the chassis; when the robot does not perform a task, a standby posture is kept, that is, the height of the robot is the lowest, the left and right chassis modules are symmetrically distributed about the left-right plane of the robot, and the spacing between the left and right chassis modules is the smallest; when the robot needs to perform a nursing task, the robot is moved to the side of a nursing person in the standby posture, the nursing person is supported, held horizontally or carried on the back, the height and the size of the chassis are adjusted, so that the center of gravity of the robot is the lowest and the zero moment point falls into the contact area between the robot and the ground. The device solves the problems that the existing double-arm transfer nursing robot has insufficient center of gravity adjusting capacity and is prone to instability when performing different tasks.

Description

Technical Field

[0001] This invention belongs to the field of rehabilitation medical equipment technology, specifically relating to a lower limb device of a dual-arm transfer nursing robot for multiple nursing tasks. Background Technology

[0002] Dual-arm transfer nursing robots are robots that move patients by mimicking human actions such as helping and carrying. For safety reasons, dual-arm transfer nursing robots are required to have good stability and postural balance when performing different transfer tasks. Existing dual-arm transfer nursing robots mainly have two types of lower limbs: chassis-based and bipedal. Chassis-based mechanisms have the advantages of a large support area, good stability, and high travel speed, but they are prone to instability when performing carrying tasks. To maintain balance, the chassis needs to be designed to be very large, resulting in a bulky robot, a large footprint, and reduced travel speed. Bipedal mechanisms allow the legs to be separated, placing the human-robot center of gravity within the support area of ​​both legs, providing better center of gravity adjustment capabilities. However, during movement, one leg needs to be off the ground, creating a single-point support with a small force application area, making them prone to instability during movement. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a lower limb device for a dual-arm transfer nursing robot designed for multiple nursing tasks.

[0004] The technical solution adopted by the present invention to solve the aforementioned technical problem is as follows:

[0005] A lower limb device for a dual-arm transfer nursing robot for multiple nursing tasks is characterized in that the device includes a body height adjustment mechanism, a chassis separation drive mechanism, and a detachable chassis mechanism; the body height adjustment mechanism is used to adjust the robot height, and the detachable chassis mechanism includes a left chassis module and a right chassis module, which can move closer to or further away from each other under the action of the chassis separation drive mechanism.

[0006] When the robot is not performing a task, it maintains a standby posture, that is, the robot height is at its lowest, the left and right chassis modules are symmetrically distributed about the left and right bisecting planes of the robot, and the distance between the left and right chassis modules is minimized.

[0007] When the robot needs to perform a support task, it moves to the side of the person being supported in a standby posture. The chassis module on the side closest to the person being supported remains stationary, while the chassis separation drive mechanism drives the chassis module on the side furthest from the person being supported to move away from the person being supported. At the same time, the front Mecanum wheel of the chassis module on the side furthest from the person being supported rotates backward, and the rear front Mecanum wheel rotates forward, until the zero torque point is located in the contact area between the robot and the ground. The chassis module on the side furthest from the person being supported then stops moving. The person being supported places their arm on the robot, and the body height adjustment mechanism adjusts the robot's height. The robot maintains its current posture and supports the person being supported to the target location. During the robot's movement, the chassis module on the side furthest from the person being supported is dynamically controlled to move away from or closer to the person being supported, so that the zero torque point is always located in the contact area between the robot and the ground.

[0008] When the robot needs to perform a horizontal hug / carrying task, it moves to the side of the person being cared for in a standby posture. The body height adjustment mechanism adjusts the robot's height. After the robot picks up / carries the person being cared for, the body height adjustment mechanism adjusts the robot's height to its lowest position. The chassis separation drive mechanism drives the left and right chassis modules to move away from each other. At the same time, the front Mecanum wheels of the left and right chassis modules rotate backward, and the rear Mecanum wheels of the left and right chassis modules rotate forward until the zero torque point is located in the contact area between the robot and the ground. The left and right chassis modules stop moving away from each other, and the robot maintains the current horizontal hug / carrying posture to transfer the person being cared for to the target location. During the robot's movement, the left and right chassis modules are dynamically controlled to move away from or closer to each other, so that the zero torque point is always located in the contact area between the robot and the ground.

[0009] Furthermore, the body height adjustment mechanism includes a first support arm, a second support arm, electric cylinders, a connecting frame, a lifting base, and a lifting platform; the middle parts of the first and second support arms are hinged together to form a scissor structure, and the two scissor structures are symmetrically arranged on the left and right sides of the lifting base and the lifting platform. The upper end of the first support arm is slidably connected to the lifting platform, and the lower end of the first support arm is connected to the lifting base. The upper end of the second support arm is hinged to the lifting platform, and the lower end of the second support arm is simultaneously connected to the connecting frame and the lifting base. The connecting frame is slidably connected to the lifting base. The bottoms of the two electric cylinders are hinged to the connecting frame, and the push rods of the electric cylinders are hinged to the middle parts of the corresponding first support arms.

[0010] Furthermore, the chassis separation drive mechanism includes a lead screw motor, a lead screw, a lead screw nut, a lead screw box base, a slider, and a chassis connecting frame; the lead screw box base is located below the lifting base, and the bottom of the lead screw box base is provided with multiple guide rails; two lead screw motors are symmetrically arranged in the middle of the lead screw box base, and the output shaft of each lead screw motor is connected to a lead screw, a lead screw nut is slidably connected to the lead screw, the chassis connecting frame is connected to the corresponding lead screw nut, and the sliders at both ends of the chassis connecting frame are slidably connected to the guide rails at the bottom of the lead screw box base.

[0011] Furthermore, both the left and right chassis modules include a chassis wheel frame, a front Mecanum wheel, and a rear Mecanum wheel; the chassis wheel frame is connected to a corresponding slider of the chassis separation drive mechanism, and the front and rear Mecanum wheels are respectively connected to the chassis wheel frame via Mecanum wheel drive motors, with pressure sensors installed on both the front and rear Mecanum wheels.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] This invention addresses the shortcomings of existing dual-arm transfer nursing robots, such as the insufficient center of gravity adjustment capability of the chassis-type lower limb mechanism and the instability of the bipedal lower limb mechanism during movement. It designs a lower limb device for a dual-arm transfer nursing robot designed for multiple nursing tasks. The chassis is designed as a detachable structure, with the left and right chassis modules able to move towards and away from each other via a drive mechanism. This is equivalent to adjusting the size of the chassis, thereby adjusting the robot's center of gravity and ensuring that the ZMP point (center of gravity) remains within the contact area between the robot and the ground during different nursing tasks, preventing instability. During the movement of the left and right chassis modules towards and away from each other, the chassis modules maintain contact with the ground, ensuring good stability. The body height adjustment mechanism is mainly used to adjust the robot's height and also assists in adjusting the robot's center of gravity. Therefore, this device has a strong center of gravity adjustment capability and a strong ability to maintain balance, making it less prone to tipping over during nursing tasks. This device allows for chassis miniaturization, enabling rapid movement. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0015] Figure 2 This is a partial enlarged view of the body vertical adjustment mechanism of the present invention from one perspective;

[0016] Figure 3 This is a partially enlarged view of the body vertical adjustment mechanism of the present invention from another perspective;

[0017] Figure 4 This is a schematic diagram of the chassis separation drive mechanism of the present invention;

[0018] Figure 5 This is a schematic diagram of the detachable chassis mechanism of the present invention;

[0019] Figures 6-9 This is a breakdown diagram of the process when the dual-arm transfer nursing robot performs an assistance task;

[0020] Figures 10-12 This is a breakdown diagram of the process when the dual-arm transfer nursing robot performs a horizontal carrying task;

[0021] Figures 13-16This is a breakdown diagram of the process when the dual-arm transfer nursing robot performs a carrying task;

[0022] In the diagram: 1. Robot head and shoulders; 2. Robot arm; 3. Body height adjustment mechanism; 4. Chassis separation drive mechanism; 5. Separable chassis mechanism;

[0023] 31. First support arm; 32. Second support arm; 33. Electric cylinder; 34. Connecting frame; 35. Lifting base; 36. Lifting platform; 37. Roller; 41. Lead screw motor; 42. Lead screw; 43. Positioning shaft; 44. Lead screw nut; 45. Lead screw box base; 46. Slider; 47. Guide rail; 48. Chassis connecting frame; 49. Lead screw box top platform; 51. Chassis wheel frame; 52. Mecanum wheel drive motor; 53. Right front Mecanum wheel; 54. Right rear Mecanum wheel; 55. Left front Mecanum wheel; 56. Left rear Mecanum wheel; 57. Battery box. Detailed Implementation

[0024] Specific embodiments are given below with reference to the accompanying drawings. These specific embodiments are only used to further illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of this application.

[0025] This invention provides a lower limb device for a dual-arm transfer nursing robot designed for multiple nursing tasks (hereinafter referred to as the device, see [link]). Figures 1-16 The robot includes a body height adjustment mechanism 3, a chassis separation drive mechanism 4, and a detachable chassis mechanism 5. The body height adjustment mechanism 3 is connected to the robot's upper limbs, and the chassis separation drive mechanism 4 is connected to the body height adjustment mechanism 3 and the detachable chassis mechanism 5. The body height adjustment mechanism 3 is used to adjust the overall height of the robot, and the chassis separation drive mechanism 4 is used to adjust the position of the chassis module of the detachable chassis mechanism 5 to prevent the robot from tipping over when performing nursing tasks.

[0026] The body height adjustment mechanism 3 includes a first support arm 31, a second support arm 32, an electric cylinder 33, a connecting frame 34, a lifting base 35, and a lifting platform 36. The first support arm 31 and the second support arm 32 are hinged together at their middle parts to form a scissor structure. The two scissor structures are symmetrically arranged on the left and right sides of the lifting base 35 and the lifting platform 36. The upper end of the first support arm 31 is slidably connected to the lifting platform 36 via a roller 37, and the lower end of the first support arm 31 is fixedly connected to the lifting base 35. The upper end of the second support arm 32 is hinged to the lifting platform 36. The lower inner side is fixedly connected to the connecting frame 34, and the lower outer side is slidably connected to the lifting base 35 via rollers 37. The connecting frame 34 is located on the lifting base 35 and can slide back and forth on the lifting base 35 as the scissor structure deforms. Two electric cylinders 33 are symmetrically arranged on the left and right sides of the connecting frame 34. The bottom of the electric cylinder 33 is hinged to the connecting frame 34, and the push rod of the electric cylinder 33 is hinged to the middle of the corresponding first support arm 31. The electric cylinder 33 drives the first support arm 31 to reciprocate along the lifting platform 36, thereby raising and lowering the lifting platform 36 and adjusting the robot height. The lifting base 35 is equipped with railings on all four sides to limit the movement of the scissor structure.

[0027] The chassis separation drive mechanism 4 includes a lead screw motor 41, a lead screw 42, a positioning shaft 43, a lead screw nut 44, a lead screw box base 45, a slider 46, and a chassis connecting frame 48. The lead screw box base 45 is connected to the lifting base 35 via a lead screw box top platform 49. Multiple guide rails 47 are arranged along the left-right direction of the robot at the bottom of the lead screw box base 45. Two lead screw motors 41 are symmetrically arranged in the middle of the lead screw box base 45, and the output shaft of each lead screw motor 41 is connected to a lead screw 42. A lead screw nut 44 is slidably connected to the lead screw 42. The chassis connecting frame 48... The connecting frame 48 is fixedly connected to the corresponding lead screw nut 44. Slider 46 is provided at both ends of the chassis connecting frame 48. The slider 46 is slidably connected to the guide rail 47 at the bottom of the lead screw box base 45. The slider 46 can also be fixedly connected to the chassis wheel frame 51 corresponding to the chassis mechanism 5. The lead screw 42 is driven to rotate by the lead screw motor 41, causing the lead screw nut 44 to slide back and forth on the lead screw 42, thereby driving the chassis connecting frame 48 to slide back and forth along the guide rail 47 of the lead screw box base 45, realizing the opposite and opposite movements of the two chassis modules of the separable chassis mechanism 5. A positioning shaft 43 is also provided on the lead screw motor 41, and the lead screw nut 44 is slidably connected to the positioning shaft 43, increasing the positioning accuracy of the lead screw nut 44.

[0028] The detachable chassis mechanism 5 includes a symmetrically arranged left chassis module and a right chassis module. The left chassis module includes a chassis wheel frame 51, a left front Mecanum wheel 55, and a left rear Mecanum wheel 56. The chassis wheel frame 51 is fixedly connected to the corresponding slider 46 of the chassis separation drive mechanism 4. The left front Mecanum wheel 55 and the left rear Mecanum wheel 56 are respectively connected to the chassis wheel frame 51 through a Mecanum wheel drive motor 52. Pressure sensors are installed on both the left front Mecanum wheel 55 and the left rear Mecanum wheel 56 to measure the pressure on the Mecanum wheel. A battery box 57 is also provided on the chassis wheel frame 51, and the battery box 57 is also connected to the slider 46 of the chassis separation drive mechanism 4. The right chassis module includes a chassis wheel frame 51, a right front Mecanum wheel 53, and a right rear Mecanum wheel 54, and their connections are the same as those of the left chassis module.

[0029] To ensure the robot remains stable during nursing tasks, pressure sensors monitor the pressure on the Mecanum wheels. The control system predicts the ZMP point position based on the pressure values ​​from the four sensors and dynamically adjusts the ZMP point position by controlling the positions of the two chassis modules of the separable chassis mechanism 5. This ensures the ZMP point is located within the contact area between the robot and the ground, specifically the quadrilateral area enclosed by the contact points of the robot's four Mecanum wheels and the ground, maintaining stability during robot movement. The ZMP point (zero torque point) is the point where the horizontal component (the component torque on the x and y axes) of the resultant torque of the ground forces acting on the robot is zero.

[0030] When the robot is not performing a task, it is in standby mode. The robot is required to have the characteristics of rapid movement and a small footprint. In this standby posture, the push rod of the electric cylinder 33 is retracted to its shortest length, the connecting frame 34 is located at the front end of the lifting base 35, and the first support arm 31 is located at the front end of the lifting platform 36. Both the first support arm 31 and the second support arm 32 are close to horizontal, the lifting platform 36 is at its lowest position, the robot's height and center of gravity are at their lowest, improving stability. Simultaneously, the left and right chassis modules of the separable chassis mechanism 5 are located directly below the robot, with minimal spacing between them, minimizing the robot's chassis size. The robot as a whole can complete various movement requirements through the cooperation of its four Mecanum wheels.

[0031] When the robot performs a assistance task, it moves to the side of the person being assisted from a standby posture (see [link]). Figure 6 The person being cared for places their arm on the robot's head and shoulder, with the robot positioned away from the person on one side (towards the side closest to the person being cared for). Figure 1(Taking the right side of the robot as an example) The lead screw motor 41 drives the lead screw 42 to rotate, causing the lead screw nut 44 to slide on the lead screw 42 towards the side away from the person being helped. At the same time, the chassis wheel frame 51 is moved away from the person being helped through the chassis connecting frame 48. Simultaneously, the front Mecanum wheel (right front Mecanum wheel 53) on the side away from the person being helped rotates backward, and the rear Mecanum wheel (right rear Mecanum wheel 54) rotates forward, assisting the chassis wheel frame 51 in moving. This continues until the control system determines that the ZMP point is within the contact area between the robot and the ground. The lead screw motor 41 stops rotating, and the lead screw nut 44 remains in its current position, preventing the chassis wheel frame 51 on the side away from the person being helped from moving outward. The chassis wheel frame 51 on the side closer to the person being helped remains stationary throughout the process to prevent collision with the person's lower limbs. Through the aforementioned operation, the robot's center of gravity is adjusted so that the ZMP point is within the contact area between the robot and the ground, ensuring the stability of the robot when performing assistance actions (see...). Figure 7 The robot's height is adjusted by the body height adjustment mechanism 3 to maintain it in a suitable position and improve the comfort of assistance. Specifically, the push rod of the electric cylinder 33 extends, driving the first support arm 31 and the second support arm 32 to rotate, which in turn pushes the connecting frame 34 to slide towards the rear end of the lifting base 35, causing the lifting platform 36 to gradually rise until the robot's head and shoulders 1 are raised to a suitable position. At this point, the push rod of the electric cylinder 33 stops extending and remains in the current position (see...). Figure 8 Then, robotic arm 2 completes the waist-hugging motion (see...). Figure 9 The robot maintains its current supporting posture and helps the person being cared for to the target location. During the robot's movement, the chassis module on the side away from the person being cared for is dynamically controlled to move away from or closer to the person being cared for, so that the zero torque point is always located in the contact area between the robot and the ground.

[0032] When the robot performs a horizontal carrying task, it moves from a standby position to the bedside of the person being cared for. The robot's height is adjusted using the body height adjustment mechanism 3, ensuring that the robot arm 2 is at a suitable height to support the person being cared for. Then, the robot arm 2 extends and supports the back and buttocks of the person being cared for, carrying them away from the bedside in a horizontal carrying (i.e., "princess carry") position (see...). Figure 10 Once the person being cared for has completely moved away from the bedside, the push rod of the electric cylinder 33 of the body height adjustment mechanism 3 retracts, causing the first support arm 31 and the second support arm 32 to rotate. This, in turn, pushes the connecting frame 34 to slide towards the front end of the lifting base 35, lowering the lifting platform 36 until the person being cared for feels the height is suitable. If the person being cared for does not require a certain height, the height of the lifting platform 36 is adjusted to its lowest point until the connecting frame 34 slides to the front end of the lifting base 35. This lowers the overall center of gravity of the robot and the person being cared for, improving the stability of the robot during operation (see...). Figure 11After the robot height is adjusted, the two lead screw motors 41 of the chassis separation drive mechanism 4 drive their respective lead screws 42 to rotate, causing the lead screw nuts 44 to slide on their respective lead screws 42. This, in turn, drives the two chassis wheel frames 51 to move in opposite directions, i.e., slide towards the sides of the robot, through their respective chassis connecting frames 48. At the same time, the right front Mecanum wheel 53 and the left front Mecanum wheel 55 rotate backward, while the left rear Mecanum wheel 56 and the right rear Mecanum wheel 54 rotate forward, assisting the chassis wheel frames 51 in moving. This continues until the control system determines that the ZMP point is within the contact area between the robot and the ground. At this point, the lead screw motors 41 stop rotating, the lead screw nuts 44 remain in their current positions, and the chassis wheel frames 51 stop moving (see...). Figure 12 The robot maintains its current horizontal holding posture and transfers the person being cared for to the target location. During the robot's movement, the left and right chassis modules are dynamically controlled to move away from or closer to each other, so that the zero torque point is always located within the contact area between the robot and the ground.

[0033] When the robot performs a carrying task, it moves from a standby position to the bedside of the person being cared for. The robot's height is adjusted using the body height adjustment mechanism 3, thereby adjusting the robot arm 2 to a suitable height. The person being cared for wraps their arms around the robot's head and shoulders 1, and the robot arm 2 extends to carry the person away from the bedside in a carrying posture (see...). Figure 13-14 When the person being cared for leaves the bedside, the push rod of the electric cylinder 33 of the body height adjustment mechanism 3 retracts, causing the first support arm 31 and the second support arm 32 to rotate. This, in turn, pushes the connecting frame 34 to slide towards the front end of the lifting base 35, lowering the lifting platform 36 until the person being cared for feels the height is suitable. If the person being cared for does not require a certain height, the height of the lifting platform 36 is adjusted to its lowest point until the connecting frame 34 slides to the front end of the lifting base 35. This lowers the overall center of gravity of the robot and the person being cared for, improving the stability of the robot during operation (see...). Figure 15 After the robot height is adjusted, the two lead screw motors 41 of the chassis separation drive mechanism 4 drive their respective lead screws 42 to rotate, causing the lead screw nuts 44 to slide on their respective lead screws 42. This, in turn, drives the two chassis wheel frames 51 to move in opposite directions, i.e., slide towards the sides of the robot, through their respective chassis connecting frames 48. At the same time, the right front Mecanum wheel 53 and the left front Mecanum wheel 55 rotate backward, while the left rear Mecanum wheel 56 and the right rear Mecanum wheel 54 rotate forward, assisting the chassis wheel frames 51 in moving. This continues until the control system determines that the ZMP point is within the contact area between the robot and the ground. At this point, the lead screw motors 41 stop rotating, the lead screw nuts 44 remain in their current positions, and the chassis wheel frames 51 stop moving (see...). Figure 16 The robot maintains its current horizontal holding posture and transfers the person being cared for to the target location.

[0034] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A lower limb device for a dual-arm transfer nursing robot designed for multiple nursing tasks, characterized in that, The device includes a body height adjustment mechanism, a chassis separation drive mechanism, and a detachable chassis mechanism; the body height adjustment mechanism is used to adjust the robot height, and the detachable chassis mechanism includes a left chassis module and a right chassis module. Under the action of the chassis separation drive mechanism, the left chassis module and the right chassis module can move closer to or further away from each other. When the robot is not performing a task, it maintains a standby posture, that is, the robot height is at its lowest, the left and right chassis modules are symmetrically distributed about the left and right bisecting planes of the robot, and the distance between the left and right chassis modules is minimized. When the robot needs to perform a support task, it moves to the side of the person being supported in a standby posture. The chassis module on the side closest to the person being supported remains stationary, while the chassis separation drive mechanism drives the chassis module on the side furthest from the person being supported to move away from the person being supported. At the same time, the front Mecanum wheel of the chassis module on the side furthest from the person being supported rotates backward, and the rear front Mecanum wheel rotates forward, until the zero torque point is located in the contact area between the robot and the ground. The chassis module on the side furthest from the person being supported then stops moving. The person being supported places their arm on the robot, and the body height adjustment mechanism adjusts the robot's height. The robot maintains its current posture and supports the person being supported to the target location. During the robot's movement, the chassis module on the side furthest from the person being supported is dynamically controlled to move away from or closer to the person being supported, so that the zero torque point is always located in the contact area between the robot and the ground. When the robot needs to perform a horizontal hug / carrying task, it moves to the side of the person being cared for in a standby posture. The body height adjustment mechanism adjusts the robot's height. After the robot picks up / carries the person being cared for, the body height adjustment mechanism adjusts the robot's height to its lowest position. The chassis separation drive mechanism drives the left and right chassis modules to move away from each other. At the same time, the front Mecanum wheels of the left and right chassis modules rotate backward, and the rear Mecanum wheels of the left and right chassis modules rotate forward until the zero torque point is located in the contact area between the robot and the ground. The left and right chassis modules stop moving away from each other, and the robot maintains the current horizontal hug / carrying posture to transfer the person being cared for to the target location. During the robot's movement, the left and right chassis modules are dynamically controlled to move away from or closer to each other, so that the zero torque point is always located in the contact area between the robot and the ground.

2. The lower limb device of the dual-arm transfer nursing robot for multiple nursing tasks according to claim 1, characterized in that, The body height adjustment mechanism includes a first support arm, a second support arm, electric cylinders, a connecting frame, a lifting base, and a lifting platform. The first and second support arms are hinged together at their middle parts to form a scissor structure. The two scissor structures are symmetrically arranged on the left and right sides of the lifting base and the lifting platform. The upper end of the first support arm is slidably connected to the lifting platform, and the lower end of the first support arm is connected to the lifting base. The upper end of the second support arm is hinged to the lifting platform, and the lower end of the second support arm is simultaneously connected to the connecting frame and the lifting base. The connecting frame is slidably connected to the lifting base. The bottom of the two electric cylinders is hinged to the connecting frame, and the push rod of the electric cylinder is hinged to the middle part of the corresponding first support arm.

3. The lower limb device of the dual-arm transfer nursing robot for multiple nursing tasks according to claim 1 or 2, characterized in that, The chassis separation drive mechanism includes a lead screw motor, a lead screw, a lead screw nut, a lead screw box base, a slider, and a chassis connecting frame. The lead screw box base is located below the lifting base, and multiple guide rails are provided at the bottom of the lead screw box base. Two lead screw motors are symmetrically arranged in the middle of the lead screw box base. The output shaft of each lead screw motor is connected to a lead screw, and a lead screw nut is slidably connected to the lead screw. The chassis connecting frame is connected to the corresponding lead screw nut, and the sliders at both ends of the chassis connecting frame are slidably connected to the guide rails at the bottom of the lead screw box base.

4. The lower limb device of the dual-arm transfer nursing robot for multiple nursing tasks according to claim 3, characterized in that, Both the left and right chassis modules include a chassis wheel frame, a front Mecanum wheel, and a rear Mecanum wheel. The chassis wheel frame is connected to the corresponding slider of the chassis separation drive mechanism. The front and rear Mecanum wheels are connected to the chassis wheel frame through Mecanum wheel drive motors, and pressure sensors are installed on both the front and rear Mecanum wheels.

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