Lower limb rehabilitation robot based on spatial mechanism

Abstract

The invention relates to a lower limb rehabilitation robot based on a spatial mechanism, which comprises a rack, the spatial mechanism, a motor and a seat supporting system, and is characterized in that the spatial mechanism comprises two rotating pairs, a spherical pair and a cylindrical pair to form a single-degree-of-freedom spatial connecting rod mechanism to drive pedals to realize simulation of a gait track in a three-dimensional space; more comprehensive and accurate lower limb rehabilitation track fitting can be provided; the length of the rod piece is adjusted through a through groove structure, multi-mode adjustment is achieved, and the application range of the mechanism is widened; after the space mechanism is optimized, the contour error of the gait track is small, more accurate fitting of the gait track of the human body can be achieved, and great significance is achieved for improving the rehabilitation training effect.

Description

Technical Field

[0001] The present invention relates to the field of rehabilitation equipment, and in particular to a lower limb rehabilitation robot based on a spatial mechanism. Background Art

[0002] Lower limb rehabilitation robots help patients achieve lower limb rehabilitation training by simulating the human gait trajectory. Currently, lower limb rehabilitation robots on the market mainly use fixed gait trajectories or two-dimensional planar motion to simulate gait trajectories. They lack the ability to simulate complex gaits and are difficult to adapt to the rehabilitation needs of different patients. Traditional planar mechanism lower limb rehabilitation robots project the human gait trajectory onto the sagittal plane, retaining only two-dimensional trajectory information; however, this method ignores the displacement information of the coronal plane, which is crucial for capturing the center of gravity transfer of the lower limbs during walking; although the sagittal plane projection retains most of the shape information of the gait trajectory, the lack of coronal plane data limits the comprehensiveness and accuracy of the rehabilitation process.

[0003] Therefore, designing a lower limb rehabilitation robot that can provide multi-degree-of-freedom movement is of great significance to improving the effect of rehabilitation training. Summary of the Invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a lower limb rehabilitation robot based on a spatial mechanism, which adopts a spatial multi-link mechanism to enable the robot to simulate different gaits in three-dimensional space, thereby improving the effect and adaptability of rehabilitation training.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A lower limb rehabilitation robot based on a spatial mechanism, which is mainly composed of a frame, a spatial mechanism, a motor, and a seat support system. The seat support system is located in the middle of the frame and is equipped with a seat cushion. Two groups of spatial mechanisms are symmetrically arranged on both sides of the frame. The spatial mechanism is composed of two revolute pairs, a spherical pair, and a cylindrical pair to form a single-degree-of-freedom spatial linkage mechanism. The driving end of the spatial mechanism is connected to the motor, and the execution end of the spatial mechanism is connected to the foot pedal. The motor drives the spatial mechanism to drive the foot pedal to realize the simulation of different gaits in three-dimensional space.

[0006] Furthermore, the spatial mechanism includes an AB rod, a BCD rod, a DE rod and a CF rod, wherein the A end of the AB rod is rotatably connected to the side of the frame, the B end of the AB rod is provided with a ball hinge and is connected to the BCD rod through the ball hinge, the BCD rod is a planar right-angle rod, the CD segment and the DE rod form a cylindrical pair at the D end, the E end of the DE rod is rotatably connected to the bottom of the frame, the CF rod is a spatial rod and is folded between the C end and the F end to form a certain angle, the C end of the CF rod is adjustably connected to the C end of the BCD rod along the direction of the CD rod, and the foot pedal is provided at the F end of the CF rod.

[0007] Furthermore, the BC section of the BCD rod is provided with a slide groove parallel to the direction of the CD rod, the CF rod is bent at G, and the CG section of the CF rod is connected to the slide groove of the BC section by bolts.

[0008] Furthermore, scale lines are provided next to the slide groove, and the scale spacing corresponds to the patient's height adjustment range.

[0009] Furthermore, the D end of the DE rod is provided with a cylindrical guide sleeve, and the D end of the BCD rod is passed through the cylindrical guide sleeve.

[0010] Furthermore, the A end of the AB rod is rotatably connected to the side of the frame through a rotating shaft and a bearing, and a driven sprocket is fixed to the A end. The driven sprocket is coaxially arranged with the rotating shaft and connected to the motor through a chain.

[0011] Furthermore, the E end of the DE rod is rotatably connected to the frame through a bearing.

[0012] Furthermore, the contact surface between the foot pedal and the patient's foot is integrated with a pressure sensor, which can monitor the force data in three dimensions: sagittal plane, coronal plane and axial plane in real time.

[0013] Furthermore, the seat cushion is a heatable seat cushion, and the seat cushion height is adjustable by adjusting the seat support system.

[0014] Furthermore, a through hole of a topological structure is opened in a non-critical force-bearing area of ​​a rod of the spatial mechanism.

[0015] Beneficial effects: 1. The present invention adopts an optimized multi-link spatial mechanism, which enables the mechanism to drive the pedals to realize gait trajectory simulation in three-dimensional space. Compared with the traditional planar motion mechanism, the present invention can obtain force data in the sagittal plane, coronal plane and axial plane. Rehabilitation training based on this data is more conducive to the comprehensiveness and accuracy of rehabilitation.

[0016] 2. The spatial linkage mechanism of the present invention includes two revolute pairs, a ball pair, and a cylindrical pair, which can simulate the gait trajectory of the pedal in three-dimensional space. The mechanism is also provided with an adjustment point, which realizes the adjustment of the rod length through the cooperation of the slide groove and the bolt to adapt to the rehabilitation patients of different body shapes and achieve better adaptability.

[0017] 3. The seat support system of the present invention is provided with a height-adjustable seat cushion and a heatable seat cushion, which improves the comfort of rehabilitation training and is more humane. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the overall structure of the present invention; Figure 2 A schematic side view of the overall structure of the present invention; Figure 3 Schematic diagram of the spatial mechanism of the present invention; Figure 4 A schematic diagram of a cylindrical pair of a spatial mechanism of the present invention; Figure 5 Schematic diagram of the principle of the spatial mechanism of the present invention; Figure 6 Schematic diagram of the optimization process of the spatial mechanism of the present invention.

[0019] Reference numerals: 1. frame, 2. AB rod, 3. BCD rod, 4. CF rod, 5. DE rod, 6. ball hinge, 7. guide sleeve, 8. motor, 9. pedal, 10. seat, 11 slide, 12 motor support seat, 13 chain. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1-5 As shown, a lower limb rehabilitation robot based on a spatial mechanism is mainly composed of a frame 1, a spatial mechanism, a motor 8, and a seat support system. The seat support system is located in the middle of the frame 1 and is equipped with a height-adjustable seat cushion 10. Two groups of spatial mechanisms are symmetrically arranged on both sides of the frame 1 of the lower limb rehabilitation robot. Each spatial mechanism is composed of two revolute pairs (R), a spherical pair (S) and a cylindrical pair (C) to form a single-degree-of-freedom spatial linkage mechanism. The driving end of the spatial mechanism is connected to the motor 8, and the execution end of the spatial mechanism is connected to the foot pedal 9. The motor 8 drives the spatial mechanism to drive the foot pedal 9 to realize the simulation of different gaits in three-dimensional space.

[0022] Specifically, the spatial mechanism includes an AB rod 2, a BCD rod 3, a DE rod 5 and a CF rod 4, wherein the A end of the AB rod 2 is rotatably connected to the side of the frame 1 through a rotating shaft and a bearing, the B end of the AB rod 2 is provided with a ball hinge 6 and is connected to the BCD rod 3 through the ball hinge 6, the BCD rod 3 is a plane right-angle rod, the CD segment and the DE rod 5 form a cylindrical pair at the D end, the D end of the DE rod 5 is provided with a cylindrical guide sleeve 7, the D end of the BCD rod 3 is passed through the guide sleeve 7, the E end of the DE rod 5 is rotatably connected to the bottom surface of the frame 1 through a bearing and a bearing seat, the CF rod 4 is a spatial rod, which is folded between the C end and the F end to form a certain angle, the C end of the CF rod 4 and the C end of the BCD rod 3 are adjustably connected along the direction of the CD rod, and the foot pedal 9 is arranged at the F end of the CF rod 4.

[0023] Specifically, in order to make the rehabilitation robot adapt to patients of different body shapes to better simulate the gait trajectory, an adjustable rod is set in the spatial mechanism, and the BC section of the BCD rod 3 is provided with a slide groove 11 extending along the direction of the CD rod, and the CF rod 4 is bent at G, and the CG section of the CF rod 4 is connected to the slide groove 11 of the BC section by bolts. When the bolts are not tightened, the position of the CG section in the slide groove 11 can be adjusted, and after adjustment, it is tightened by the locking nut to achieve rigid fixation; further, a scale line is provided next to the slide groove 11, and the scale spacing corresponds to the patient's height adjustment range, which is convenient for the user to quickly locate the adaptation position.

[0024] The AB rod 2 of the spatial mechanism is a crank, and a driven sprocket is fixed to the A end. The driven sprocket is coaxially arranged with the rotating shaft and connected to the motor 8 through a chain 13. The motor 8 is arranged on the motor support seat 12. The motor 8 drives the AB rod 2 to rotate, drives the spatial mechanism to move, and simulates the gait trajectory of rehabilitation training at the end.

[0025] A pressure sensor is integrated on the contact surface between the foot pedal 9 and the patient's foot. Combined with the three-dimensional movement freedom of the spatial mechanism, the pressure sensor can monitor the force data in the sagittal plane, coronal plane and axial plane in real time. Combined with this data, it can provide more comprehensive and accurate lower limb rehabilitation trajectory fitting for rehabilitation training.

[0026] This invention achieves lightweight rod design through topological weight-reducing holes. Holes are placed in non-critical stress-bearing areas of the rod, reducing material usage while ensuring adequate mechanical properties. During design, the location, number, and shape of the holes are determined based on a stress analysis of the rod, ensuring weight reduction without compromising structural stability.

[0027] In order to ensure that the rods of the spatial mechanism can cooperate with each other to achieve the best gait simulation trajectory, the spatial mechanism needs to be optimized. This invention uses a step-by-step optimization method to optimize the length of the rods, including two stages: multi-objective preliminary optimization and single-objective optimization. The specific optimization process is as follows: Figure 6 As shown, when all parameters are adjustable, multiple target trajectories are first set, and multi-objective optimization is performed. After obtaining the optimal adjustable parameters, single-objective optimization is performed to finally obtain the optimal parameter values. The most critical subtask in the multi-mode optimization method is to determine which of all parameters is the best adjustable parameter, and to determine the best adjustment parameter value and the remaining basic parameter values. The present invention adopts a distributed optimization method, that is, firstly adopting a multi-objective optimization method to comprehensively select and determine the best adjustable rod, and then adopting a single-objective optimization method to determine the specific adjustment value and other parameter values, thereby reducing computational redundancy. The optimized rod length reduces the error in gait trajectory fitting and finds the adjustable rod to realize multi-mode conversion to accommodate more users.

[0028] The lower limb rehabilitation robot is used in conjunction with a control system, which includes a single-chip microcomputer. The motor 8, pressure sensor, and heating pad are all connected to the control system. The pressure sensor is used to detect the pressure value during exercise and promptly feed back to the single-chip microcomputer. The heating pad is set on the seat cushion 10, and the heating function is turned on or off according to the instructions of the control system. The lower limb rehabilitation robot has two modes: passive rehabilitation and active rehabilitation. In the passive rehabilitation mode, the patient's lower limb movement is driven by the rehabilitation mechanism, and in the active rehabilitation movement, the patient drives the rehabilitation mechanism to move. In both modes, the output torque of the motor 8 can be adjusted, which can achieve phased training.

[0029] The system also features multiple safety measures, including real-time pressure monitoring, which uses pressure sensors to continuously monitor the force applied to the patient's lower limbs to prevent overload training. Furthermore, the system features automatic and manual emergency stop functions, allowing for rapid termination of training in the event of an emergency, preventing injury. Through this structural design, the lower limb rehabilitation robot of the present invention can meet the needs of patients at different stages of rehabilitation, enhance training effectiveness, and ensure safety.

[0030] The present invention adopts the RSCR spatial mechanism as the basic configuration for gait rehabilitation, which can provide more comprehensive and accurate lower limb rehabilitation trajectory fitting; the through-slot structure is used to adjust the rod length, realizing multi-mode adjustment and improving the applicability of the mechanism; the size of the spatial mechanism is optimized in two steps, and the contour error of the gait trajectory is less than 1 cm, which can more accurately fit the human gait trajectory.

[0031] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A lower limb rehabilitation robot based on a spatial mechanism, characterized in that: The lower limb rehabilitation robot is mainly composed of a frame, a spatial mechanism, a motor, and a seat support system. The seat support system is located in the middle of the frame and is equipped with a seat cushion. Two groups of spatial mechanisms are symmetrically arranged on both sides of the frame. The spatial mechanism is composed of two revolute pairs, a spherical pair, and a cylindrical pair to form a single-degree-of-freedom spatial linkage mechanism. The driving end of the spatial mechanism is connected to the motor, and the execution end of the spatial mechanism is connected to the foot pedal. The motor drives the spatial mechanism to drive the foot pedal to realize the simulation of different gaits in three-dimensional space.

2. A lower limb rehabilitation robot based on a spatial mechanism according to claim 1, characterized in that: The spatial mechanism includes an AB rod, a BCD rod, a DE rod and a CF rod, wherein the A end of the AB rod is rotatably connected to the side of the frame, the B end of the AB rod is provided with a ball hinge and is connected to the BCD rod through the ball hinge, the BCD rod is a plane right-angle rod, the CD segment and the DE rod form a cylindrical pair at the D end, the E end of the DE rod is rotatably connected to the bottom of the frame, the CF rod is a spatial rod and is folded between the C end and the F end to form a certain angle, the C end of the CF rod is adjustably connected to the C end of the BCD rod along the direction of the CD rod, and the foot pedal is provided at the F end of the CF rod.

3. The lower limb rehabilitation robot based on a spatial mechanism according to claim 2, characterized in that: The BC section of the BCD rod is provided with a slide groove parallel to the direction of the CD rod. The CF rod is bent at G, and the CG section of the CF rod is connected to the slide groove of the BC section by bolts.

4. The lower limb rehabilitation robot based on a spatial mechanism according to claim 3, characterized in that: Scale lines are provided beside the slide, and the scale spacing corresponds to the patient's height adjustment range.

5. The lower limb rehabilitation robot based on a spatial mechanism according to claim 2, characterized in that: The D end of the DE rod is provided with a cylindrical guide sleeve, and the D end of the BCD rod is passed through the cylindrical guide sleeve.

6. The lower limb rehabilitation robot based on a spatial mechanism according to claim 2, characterized in that: The A end of the AB rod is rotatably connected to the side of the frame through a rotating shaft and a bearing, and a driven sprocket is fixed to the A end. The driven sprocket is coaxially arranged with the rotating shaft and connected to the motor through a chain.

7. The lower limb rehabilitation robot based on a spatial mechanism according to claim 2, characterized in that: The E end of the DE rod is rotatably connected to the frame through a bearing.

8. The lower limb rehabilitation robot based on a spatial mechanism according to claim 1, characterized in that: The contact surface between the foot pedal and the patient's foot is integrated with a pressure sensor, which can monitor the force data in three dimensions: sagittal plane, coronal plane and axial plane in real time.

9. The lower limb rehabilitation robot based on a spatial mechanism according to claim 1, characterized in that: The seat cushion is a heatable seat cushion, and the seat cushion height is adjustable by adjusting the seat support system.

10. The lower limb rehabilitation robot based on a spatial mechanism according to claim 2, characterized in that: A through hole of a topological structure is opened in a non-critical stress-bearing area of ​​a rod of a spatial mechanism.

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