Exoskeleton and human joint rotation center offset error measuring device and method
By designing a device to measure the offset error between the rotation center of the exoskeleton and human joints, and using a ruler to measure the offset error and adjust the exoskeleton joint connection center, the complexity and low accuracy of the coaxial adjustment of the exoskeleton system were solved, and efficient and accurate coaxial adjustment was achieved, thereby improving wearing comfort and assistance effect.
Patent Information
- Application Number
- CN202510785996.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2025-09-26
AI Technical Summary
When existing exoskeleton systems adjust the connection center of the exoskeleton system to be coaxial with the rotation center of the human joint, the process is complicated and the accuracy is low, and there is a lack of simple and efficient error elimination devices.
A device for measuring the offset error between the rotation center of an exoskeleton and a human joint is designed. The device includes a measuring frame, a sliding frame, a slider, a rotating shaft, and a rod. The offset error is measured by a ruler and the connection center of the exoskeleton joint is adjusted to a coaxial position.
It achieves efficient and accurate coaxial adjustment between the exoskeleton joint connection center and the human joint rotation center, simplifies the adjustment process, and improves wearing comfort and power assistance effect.
Smart Images
Figure CN120697003A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of wearable devices, and in particular relates to a device and method for measuring the offset error between the rotation center of an exoskeleton and a human joint. Background Art
[0002] The exoskeleton system is a power-assisting device that provides assistance to human joints and shares the load through a rod structure parallel to the limbs, thereby improving the wearer's load-bearing capacity and endurance. However, when the connection center of the exoskeleton rod structure is not coaxial with the rotation center of the human joint, the exoskeleton system will generate resistance to the movement of the human joint, affecting the wearing comfort and power-assisting effect. Therefore, it is necessary to adjust the position of the connection center of the exoskeleton system and the rotation center of the human joint to make them coaxial; in the existing technology, the exoskeleton system is repeatedly adjusted based on the wearer's trial feedback to make it as coaxial as possible with the rotation center of the human joint. The correction process is complicated, with poor accuracy and low efficiency. In the existing technology, there is no simple device that can quickly eliminate the offset error between the rotation center of the exoskeleton and the human joint. Summary of the Invention
[0003] In order to overcome the shortcomings of the existing technology and improve the efficiency and accuracy of coaxial adjustment between the connection center of the exoskeleton joint and the rotation center of the human joint, the present invention provides a device and method for measuring the offset error between the rotation center of the exoskeleton and the human joint.
[0004] The technical solution adopted by the present invention to solve its technical problem is: A device for measuring the rotation center offset error between an exoskeleton and a human joint, comprising a measuring frame 1, a sliding frame 2, a slider 3, a rotating shaft 4, and a rod 7; The measuring frame 1 is a hollow square frame; the rod 7 is a long strip with adjustable length; A rod 7 is set at the center of the bottom edge of the outer frame of the measuring frame 1; the bottom edge of the outer frame of the measuring frame 1 is fixedly connected to a short side of the rod 7; a sliding frame 2 is set inside the measuring frame 1; the sliding frame 2 is a hollow rectangular frame; the two short sides of the outer frame of the sliding frame 2 are respectively slidably connected to the two side edges of the inner frame of the measuring frame 1; a slider 3 is nested in the inner frame of the sliding frame 2; the slider 3 slides along the long side of the sliding frame 2; the slider 3 is square; a through hole is set at the center of the slider 3; a rotating shaft 4 is set in the through hole; a first scale 5 is set between the inner frame and the outer frame of the side of the measuring frame 1; a second scale 6 is set between the bottom edge of the inner frame and the bottom edge of the outer frame of the sliding frame 2.
[0005] Furthermore, the 0 scale mark of the first scale 5 is the midpoint of the side of the inner frame of the measuring frame 1; the scale value of the first scale 5 gradually increases from the bottom edge to the top edge of the measuring frame 1; the 0 scale mark of the second scale 6 is the midpoint of the bottom edge of the inner frame of the measuring frame 1.
[0006] Furthermore, the measuring frame 1 and the sliding frame 2 are connected by a sliding rail.
[0007] A method for measuring the deviation of the rotation center between an exoskeleton and a human joint using a device for measuring the deviation of the rotation center between the exoskeleton and the human joint comprises the following steps: Step 1: Establish an error measurement model; The error measurement model is as follows: with the center of the measurement frame (1) as the origin, a coordinate system is established, wherein the x-axis is a straight line passing through the center of the measurement frame (1) and the midpoint of the bottom edge of the inner frame of the measurement frame (1); the y-axis is a straight line passing through the center of the measurement frame (1) and the midpoint of the side edge of the inner frame of the measurement frame (1); the angle of rotation of the exoskeleton and human joint rotation center offset error measurement device along the rotation axis (4) is ; At this time, the offset of the center of the sliding frame (2) on the first scale is R1, and the offset of the center of the sliding frame 2 on the second scale is R2; Step 2: Initialize the error measurement model; The initial state of the error measurement model is: the center of the measurement frame 1 coincides with the center of the sliding frame 2; the line connecting the 0 mark of the first scale 5 and the center of the sliding frame 2 coincides with the y-axis; the line connecting the 0 mark of the second scale 6 and the center of the sliding frame 2 coincides with the x-axis; Step 3: Set the exoskeleton joint and human joint rotation center offset error measurement device with the initialized error measurement model between the exoskeleton joint and the human joint, fix the rotation axis 4 to the exoskeleton joint connection center, and fix the rod 7 to the human joint. The angle of rotation of the human joint around the rotation axis 4 is , calculate the coordinates of the human joint rotation center in the error measurement model (E1, E2): (1) (2) Step 4: Adjust the exoskeleton joint connection center to the position of (E1, E2). At this time, the exoskeleton joint connection center is coaxial with the human joint rotation center.
[0008] The present invention has the following beneficial effects: because the slide frame is provided within the measurement frame, after the device is connected to the exoskeleton connection center and the human joint, the position coordinates of the human joint center relative to the square slide can be calculated by rotating the angle, thereby correcting offset errors with only a single measurement. When not in use, the retractable rod 7 is retracted, reducing the size of the device and making it easier to carry. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 is a schematic diagram of a measuring device of the present invention; Figure 2 is a schematic diagram of the measuring device of the present invention after rotation; In the figure, 1-measuring frame; 2-sliding frame; 3-sliding block; 4-rotating shaft; 5-first scale; 6-second scale; 7-rod. DETAILED DESCRIPTION
[0010] A device for measuring the rotation center offset error between an exoskeleton and a human joint, comprising a measuring frame 1, a sliding frame 2, a slider 3, a rotating shaft 4, and a rod 7; The measuring frame 1 is a hollow square frame; the rod 7 is a long strip with adjustable length; A rod 7 is provided at the center of the bottom edge of the outer frame of the measuring frame 1; the bottom edge of the outer frame of the measuring frame 1 is fixedly connected to a short side of the rod 7; A sliding frame 2 is provided in the measuring frame 1; the sliding frame 2 is a hollow rectangular frame; two short sides of the outer frame of the sliding frame 2 are respectively slidably connected to two side sides of the inner frame of the measuring frame 1; The inner frame of the slide frame 2 is nested with a slider 3; the slider 3 slides along the long side of the slide frame 2; the slider 3 is square; a through hole is set in the center of the slider 3; a rotating shaft 4 is set in the through hole; A first scale 5 is provided between the inner frame and the outer frame of the side of the measuring frame 1; A second scale 6 is provided between the inner frame and the outer frame of the bottom edge of the sliding frame 2; The 0 mark of the first scale 5 is the midpoint of the side of the inner frame of the measuring frame 1; the 0 mark of the second scale 6 is the midpoint of the bottom of the inner frame of the measuring frame 1; A method for measuring the offset error between an exoskeleton and a human joint rotation center includes the following steps: Step 1: Establish an error measurement model; The error measurement model is as follows: A coordinate system is established with the center of sliding frame 2 as the origin, where the x-axis is a straight line passing through the center of sliding frame 2 and the midpoint of the bottom edge of the inner frame of measurement frame 1, and the x-axis is perpendicular to the inner frame of measurement frame 1; the y-axis is a straight line passing through the center of sliding frame 2 and the midpoint of the side edge of the inner frame of measurement frame 1; The angle of the exoskeleton and human joint rotation center offset error measurement device rotating along the rotation axis 4 is At this time, the offset of the center of the sliding frame 2 on the first scale is R1, and the offset of the center of the sliding frame 2 on the second scale is R2; Step 2: Initialize the error measurement model; The initial state of the error measurement model is: The center of the measuring frame 1 coincides with the center of the sliding frame 2; the line connecting the 0 mark of the first scale 5 and the center of the sliding frame 2 coincides with the y-axis; the line connecting the 0 mark of the second scale 6 and the center of the sliding frame 2 coincides with the x-axis; Step 3: Set the exoskeleton joint and human joint rotation center offset error measurement device with the initialized error measurement model between the exoskeleton joint and the human joint, fix the rotation axis 4 to the exoskeleton joint connection center, and fix the rod 7 to the human joint. The angle of rotation of the human joint around the rotation axis 4 is , calculate the coordinates of the human joint rotation center in the error measurement model (E1, E2): (1) (2) Step 4: Adjust the exoskeleton joint connection center to the position of (E1, E2). At this time, the exoskeleton joint connection center is coaxial with the human joint rotation center. When measuring, the exoskeleton joint and the human joint rotation center offset error measuring device is set between the exoskeleton joint and the human joint; the rotation axis 4 is fixed at the center position of the connection between the exoskeleton joint; the human joint rotation center is placed near the rotation axis 4; the rod 7 is fixed to the human joint; the length of the rod 7 is adjusted so that the rotation axis 4 is located at the center of the measurement frame 1; the angle of rotation of the human joint is , record the offset on the first scale and the offset on the second scale, calculate the coordinates of the rotation center of the human joint, and adjust the connection center of the exoskeleton joint to make it coaxial.
[0011] The present invention will be further described below with reference to the accompanying drawings and examples.
[0012] join Figures 1 and 2 It has a square outer frame 1, and a length-adjustable rod 7 is connected to the bottom of the square outer frame for fixing the limb connected to the human joint to be measured. A rectangular sliding frame 2 is embedded in the square outer frame 1, and a square slider 3 is embedded in the rectangular sliding frame. A rotating shaft 4 is provided in the center of the square slider. When measuring, the rotating shaft 4 is fixed to the center position of the exoskeleton joint. Scales 5 and 6 are provided on the edges of the square outer frame and the rectangular sliding frame respectively. The zero position of the scale is at the center position of each side and the positive direction is upward and rightward respectively, which is used to measure the offset R1 and R2 of the center of the rotating shaft 4 relative to its center point in the direction of the edge of the square outer frame 1.
[0013] The measurement process of this device is as follows: 1. Initial state: See Figure 1 , place the device between the exoskeleton joint and the human joint, fix the rotating shaft 4 to the rotation center of the exoskeleton joint, visually place the center of the measured human joint near the center of the rotating shaft 4, fix the rod 7 to the limb connected to the measured human joint, adjust the length and angle of the rod 7 so that R1 and R2 are both zero, that is, the rotating shaft 4 is at the center of the square outer frame 1.
[0014] 2. Measurement process: Make the limb connected to the human joint to be measured rotate around the human joint θ Angle, while driving the device to rotate around the human joints θ Angle, read the R1 and R2 values.
[0015] 3. Offset error calculation: θ , R1 and R2 are the values of E1 and E2 calculated according to formulas (1) and (2).
[0016] (1) (2) Point (E1, E2) is the center of the human joint. Figure 1 Position in the coordinate system.
[0017] During the measurement process, if R1=R2=0, it means that there is no offset error between the rotation centers of the exoskeleton and the human joint.
[0018] In particular, when the rotation angle is 90°, that is, θ =90°, the calculation formulas (1) and (2) can be simplified to , .
[0019] Obviously, the present invention is not limited to measuring the offset error between the center of rotation of an exoskeleton and a human joint, but can also be applied to similar coaxial offset error measurement and correction. Certain improvements and other applications that do not depart from the concept of this measurement device are also within the scope of protection of this invention.
Claims
1. A device for measuring the deviation of the rotation center between an exoskeleton and a human joint, characterized by: It includes a measuring frame (1), a sliding frame (2), a slider (3), a rotating shaft (4) and a rod (7); The measuring frame (1) is a hollow square frame; the rod (7) is a long strip with adjustable length; the rod (7) is provided at the center of the bottom edge of the outer frame of the measuring frame (1); the bottom edge of the outer frame of the measuring frame (1) is fixedly connected to a short side of the rod (7); a sliding frame (2) is provided inside the measuring frame (1); the sliding frame (2) is a hollow rectangular frame; the two short sides of the outer frame of the sliding frame (2) are respectively slidably connected to the two side edges of the inner frame of the measuring frame (1); a slider (3) is nested in the inner frame of the sliding frame (2); the slider (3) slides along the long side of the sliding frame (2); the slider (3) is square; a through hole is provided at the center of the slider (3); a rotating shaft (4) is provided in the through hole; a first scale (5) is provided between the side edge of the inner frame of the measuring frame (1) and the side edge of the outer frame; a second scale (6) is provided between the bottom edge of the inner frame of the sliding frame (2) and the bottom edge of the outer frame.
2. The device for measuring the rotation center offset error between an exoskeleton and a human joint according to claim 1, characterized in that: The 0 mark of the first scale (5) is the midpoint of the side of the inner frame of the measuring frame (1); the scale of the first scale (5) increases gradually from the bottom edge to the top edge of the measuring frame (1); the 0 mark of the second scale (6) is the midpoint of the bottom edge of the inner frame of the measuring frame (1).
3. The device for measuring the rotation center offset error between an exoskeleton and a human joint according to claim 1, characterized in that: The measuring frame (1) and the sliding frame (2) are connected by a sliding rail.
4. A method for measuring the deviation between the rotation center of an exoskeleton and a human joint comprises the following steps: Step 1: Establish an error measurement model; The error measurement model is as follows: with the center of the measurement frame (1) as the origin, a coordinate system is established, wherein the x-axis is a straight line passing through the center of the measurement frame (1) and the midpoint of the bottom edge of the inner frame of the measurement frame (1); the y-axis is a straight line passing through the center of the measurement frame (1) and the midpoint of the side edge of the inner frame of the measurement frame (1); the angle of rotation of the exoskeleton and human joint rotation center offset error measurement device along the rotation axis (4) is ; At this time, the offset of the center of the sliding frame (2) on the first scale is R1, and the offset of the center of the sliding frame 2 on the second scale is R2; Step 2: Initialize the error measurement model; The initial state of the error measurement model is: the center of the measurement frame (1) coincides with the center of the sliding frame (2); the line connecting the 0 scale mark of the first scale (5) and the center of the sliding frame (2) coincides with the y-axis; the line connecting the 0 scale mark of the second scale (6) and the center of the sliding frame (2) coincides with the x-axis; Step 3: Set the exoskeleton joint and human joint rotation center offset error measurement device with the initialized error measurement model between the exoskeleton joint and the human joint, fix the rotation axis (4) to the exoskeleton joint connection center, and fix the rod (7) to the human joint. The angle of rotation of the human joint around the rotation axis (4) is , calculate the coordinates (E1, E2) of the human joint rotation center in the error measurement model as: (1) (2) Step 4: Adjust the exoskeleton joint connection center to the position of (E1, E2). At this time, the exoskeleton joint connection center is coaxial with the human joint rotation center.