Backrest rotation center self-adaptive adjustment method

Abstract

The invention belongs to the field of furniture, and discloses a backrest rotation center self-adaptive adjustment method which comprises the following steps: step 1, collecting seat surface pressure, identifying the positions of ischial tuberosities on two sides of a human body according to the seat surface pressure distribution, and calculating the positions of hip joints of the human body according to the positions of the ischial tuberosities on two sides of the human body; 2, according to the position of the hip joint of the human body, adjusting the rotation center of the backrest to move to the position the same as the coordinates of the hip joint of the human body in the front-back direction. The position of the human ischial tuberosity point on the seat surface is detected, the position of the human trunk rotating shaft is calculated, the rotating center of the backrest is adjusted to the position coinciding with the rotating center of the human body in the horizontal direction, the phenomena of back rubbing and waist losing caused by unreasonable arrangement of the rotating shaft of the backrest are eliminated, reasonable support is provided for the human body in the backward leaning state, and the human body is more comfortable. Human body waist and back injury caused by long-term use of unreasonable office chairs is avoided.

Description

[0001] This application is a divisional application. The original application number is CN2025105513384, the application date is April 29, 2025, and the invention title is "Backrest Rotation Center Adaptive Adjustment System and Method". Technical Field

[0002] This invention relates to the field of furniture, specifically to a method for adaptive adjustment of the rotation center of a backrest. Background Technology

[0003] Office chair backrests are usually mounted on a chassis, which is typically lower than the seat. The chassis and seat together form a chair seat in the conventional sense. When a person leans against the backrest and the backrest rotates, because the rotation point of the backrest is lower than the rotation point of the person, when the person leans back against the backrest and reclines, the rotation radius of the backrest is greater than the rotation radius of the person. This causes a deviation between the movement trajectory of the office chair backrest and the movement trajectory of the person's back, resulting in the backrest causing clothing to rub upwards and the backrest / lumbar support to detach from the person's waist. This is known in the industry as "back rubbing" or "waist loss".

[0004] Existing solutions mainly address the above issues through the linkage technology between the backrest and the seat. However, due to differences in body shape and seat depth among different users, the rotation axis of different users varies relative to the rotation axis of the seat. The linkage technology between the backrest and the seat cannot meet the needs of everyone, and as the reclining angle increases, the symptoms of "back rubbing" and "lower back" become more pronounced. Summary of the Invention

[0005] The purpose of this invention is to provide a method for adaptive adjustment of the backrest rotation center to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for adaptive adjustment of the backrest rotation center is implemented through a backrest rotation center adaptive adjustment system. The backrest rotation center adaptive adjustment system includes a matrix pressure sensor, a backrest, a backrest rotation bracket connected to the backrest, and a backrest lateral movement drive mechanism connected to the backrest rotation bracket. The matrix pressure sensor is disposed on the seat surface and includes a plurality of pressure sensors arranged in an array. The backrest lateral movement drive mechanism is disposed at the bottom of the chassis and is used to drive the backrest rotation bracket to move back and forth together with the backrest, thereby adjusting the rotation center of the backrest. The adaptive adjustment method for the backrest rotation center includes: Step 1: Collect seat pressure, identify the position of the ischial tuberosities on both sides of the human body based on the seat pressure distribution, and calculate the position of the hip joint based on the position of the ischial tuberosities on both sides of the human body. Step 2: Based on the position of the human hip joint, adjust the rotation center of the backrest to the same position as the human hip joint in the front-back direction.

[0007] Further, step 1 includes: A matrix pressure sensor is installed in the seat area to collect the pressure on the seat surface and output a pressure distribution image. The pressure distribution image is then processed to identify the positions of the ischial tuberosities on both sides of the human body.

[0008] Furthermore, step 1 also includes: The matrix pressure sensors are numbered and named P(X,Y) according to their row and column. The locations of the ischial tuberosities on both sides of the human body are identified from the generated pressure images, with the location of the left ischial tuberosity marked as P. a (X a ,Y a The location of the right ischial tuberosity node is marked as P. b (X) b ,Y b The distance from the front of the seat to the location of the human hip joint is (Y). a +Y b ) / 2+L1, where L1 represents the distance from the center point of the human hip joint to the front of the ischial tuberosity, X, X a X b Both represent the coordinates in the left-right direction of the seat, Y, Y a Y b All of these represent the coordinates in the fore-and-aft direction of the seat.

[0009] Furthermore, the backrest rotation bracket includes a first bracket connected to the backrest and a second bracket rotatably connected to the first bracket. The second bracket is connected to the backrest lateral movement drive mechanism, and the rotatable connection point between the first bracket and the second bracket is the rotation center of the backrest.

[0010] Furthermore, there are two backrest rotation brackets, which are respectively connected to the left and right sides of the backrest.

[0011] Furthermore, there are also two backrest lateral movement drive mechanisms, which are respectively connected to two backrest rotation brackets.

[0012] Furthermore, an elastic reset mechanism is connected between the lower end of the backrest and the main body of the seat.

[0013] Compared with the prior art, the beneficial effects of the present invention are: by detecting the position of the ischial tuberosity of the human body on the seat surface, the present invention calculates the position of the rotation axis of the human torso and adjusts the rotation center of the backrest to coincide with the rotation center of the human body in the horizontal direction, thereby eliminating the phenomenon of "back rubbing" and "lower back" caused by unreasonable setting of the rotation axis of the backrest, providing reasonable support for the human body in the reclining state, and avoiding damage to the human lower back caused by prolonged use of unreasonable office chairs. Attached Figure Description

[0014] Figure 1 This diagram shows the positional relationship between the human hip joint and the ischial tuberosity.

[0015] Figure 2 This is one of the schematic diagrams of a seat structure to which the adaptive adjustment system for the backrest rotation center of the present invention is applied.

[0016] Figure 3 This is a second schematic diagram of the seat structure to which the adaptive adjustment system for the backrest rotation center of the present invention is applied.

[0017] Figure 4 This is the third schematic diagram of the seat structure to which the adaptive adjustment system for the backrest rotation center of the present invention is applied.

[0018] In the diagram: 1. Backrest 2. Backrest rotation bracket 3. First bracket 200 4. Second bracket 201 5. Backrest lateral movement drive mechanism 6. Elastic reset mechanism 7. Seat 8. Left ischial tuberosity 9. Right ischial tuberosity 10. Matrix pressure sensor 11. Hip bone a 12. Hip joint b 13. Femur c 14. Coccyx d 15. Isch e 16. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figures 2-4 An adaptive adjustment system for the rotation center of a backrest includes a matrix pressure sensor 8, a backrest 1, a backrest rotation bracket 2 connected to the backrest 1, and a backrest lateral movement drive mechanism 3 connected to the backrest rotation bracket 2. The matrix pressure sensor 8 is disposed on the seat surface and includes a plurality of pressure sensors arranged in an array. The backrest lateral movement drive mechanism 3 is disposed at the bottom of the chassis and is used to drive the backrest rotation bracket 2 together with the backrest 1 to move back and forth (in the Y direction) to adjust the rotation center of the backrest 1.

[0021] Continue reading Figures 2-4In one embodiment of the present invention, there are two backrest rotation brackets 2, which are respectively connected to the left and right sides of the backrest 1, and there are also two backrest lateral movement drive mechanisms 3, which are respectively connected to the two backrest rotation brackets 2.

[0022] Continue reading Figure 2 and Figure 3 In one embodiment of the present invention, the backrest rotating bracket 2 includes a first bracket 200 connected to the backrest 1 and a second bracket 201 rotatably connected to the first bracket 200. The second bracket 201 is connected to the backrest transverse driving mechanism 3. The first bracket 200 is arranged laterally and the second bracket 201 is arranged longitudinally. The rotatable connection between the first bracket 200 and the second bracket 201 is the rotation center of the backrest 1, and the axis of the rotation center is arranged along the left-right direction (X direction).

[0023] Continue reading Figure 2 In one embodiment of the present invention, the backrest lateral movement drive mechanism 3 is preferably an electric slide, but pneumatic slides, electric push rods, pneumatic push rods, and other mechanisms may also be used.

[0024] Continue reading Figure 2 In one embodiment of the present invention, an elastic reset mechanism 4 is connected between the lower end of the backrest 1 and the support column of the seat. The elastic reset mechanism 4 is preferably a spring rod. When the backrest 1 leans back, the elastic reset mechanism 4 can provide support force and help the backrest 1 reset.

[0025] This invention also provides a method for adaptive adjustment of the backrest rotation center, employing the backrest rotation center adaptive adjustment system described above. Before introducing the method of this invention, a brief introduction to human anatomy is provided: such as... Figure 1 As shown, when leaning back, the axis of rotation of the human torso is the hip joint. That is, when leaning back in a seated position, the torso rotates around the hip joint. The ischial tuberosity is the lowest point of the ischium. In a normal anatomical position (upright and neutral), it is located approximately 5 cm below and behind the hip joint, with the line connecting the two making an angle of approximately 45° with the horizontal plane. The position of the hip joint relative to the ischial tuberosity is relatively fixed; therefore, the position of the hip joint can be inferred from the position of the ischial tuberosity in a seated position. To ensure that the chair back remains firmly against the back of the user when leaning back and does not slide relative to the user, the axis of rotation of the office chair back should coincide with or be close to the axis of rotation of the user.

[0026] The adaptive adjustment method for the backrest rotation center includes: Step 1: Collect seat pressure data. Based on the seat pressure distribution, identify the positions of the ischial tuberosities on both sides of the body. Calculate the position of the hip joint based on the positions of the ischial tuberosities on both sides of the body. Specifically, this includes: like Figure 4As shown, a matrix pressure sensor 8 is installed in the seat area, which can collect the pressure on the seat and output a pressure distribution image. The pressure distribution image is processed to identify the position of the ischial tuberosities on both sides of the human body.

[0027] The matrix pressure sensors 8 mounted on the seat surface are numbered, such as... Figure 4 As shown: The sensor is named P(X,Y) according to its row and column. The locations of the ischial tuberosities on both sides of the human body are identified based on the generated pressure image, with the location of the left ischial tuberosity marked as P. a (X a ,Y a The location of the right ischial tuberosity node is marked as P. b (X) b ,Y b Then, the distance from the position of the human body's rotation axis to the front end of the seat is (Y). a +Y b ) / 2+L1, where L1 represents the distance from the center point of the human hip joint to the anterior end of the ischial tuberosity, usually 5cm, X, X a X b Both represent the coordinates in the left-right direction of the seat, Y, Y a Y b All of these represent the coordinates in the fore-and-aft direction of the seat.

[0028] Step 2: Based on the position of the human hip joint, the control system sends a command to the backrest lateral movement drive mechanism 3. The backrest lateral movement drive mechanism 3 drives the backrest rotation bracket 2 and the backrest 1 to move back and forth together, so that the rotation center of the backrest 1 moves to the same position as the human hip joint in the Y direction.

[0029] The control system knows the initial Y coordinate of the backrest rotation center, and can determine the distance and direction that the backrest rotation center needs to move based on the position of the human hip joint.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for adaptive adjustment of the backrest rotation center, characterized in that, This is achieved through an adaptive adjustment system for the backrest rotation center, which includes a matrix pressure sensor (8), a backrest (1), a backrest rotation bracket (2) connected to the backrest (1), and a backrest lateral movement drive mechanism (3) connected to the backrest rotation bracket (2). The matrix pressure sensor (8) is located on the seat surface and includes several pressure sensors arranged in an array. The backrest lateral movement drive mechanism (3) is located at the bottom of the chassis and is used to drive the backrest rotation bracket (2) to move back and forth together with the backrest (1), thereby adjusting the rotation center of the backrest (1). The adaptive adjustment method for the backrest rotation center includes: Step 1: Collect seat pressure, identify the position of the ischial tuberosities on both sides of the human body based on the seat pressure distribution, and calculate the position of the hip joint based on the position of the ischial tuberosities on both sides of the human body. Step 2, adjust the backrest (1) rotation center to the same position as the human hip joint in the front-back direction, according to the position of the human hip joint.

2. The method for adaptive adjustment of the backrest rotation center according to claim 1, characterized in that, Step 1 includes: A matrix pressure sensor (8) is installed in the seat area. The pressure of the seat is collected by the matrix pressure sensor (8), and a pressure distribution image is output. The pressure distribution image is processed to identify the position of the ischial tuberosities on both sides of the human body.

3. The method for adaptive adjustment of the backrest rotation center according to claim 2, characterized in that, Step 1 further includes: The matrix pressure sensors (8) are numbered and named P(X,Y) according to the row and column of each pressure sensor. The locations of the ischial tuberosities on both sides of the human body are identified based on the generated pressure images, with the location of the left ischial tuberosity marked as P. a (X a ,Y a The location of the right ischial tuberosity node is marked as P. b (X) b ,Y b The distance from the front of the seat to the location of the human hip joint is (Y). a +Y b ) / 2+L1, where L1 represents the distance from the center point of the human hip joint to the front of the ischial tuberosity, X, X a X b Both represent the coordinates in the left-right direction of the seat, Y, Y a Y b All of these represent the coordinates in the fore-and-aft direction of the seat.

4. A method for adaptive adjustment of the backrest rotation center according to any one of claims 1-3, characterized in that, The backrest rotation bracket (2) includes a first bracket (200) connected to the backrest (1) and a second bracket (201) rotatably connected to the first bracket (200). The second bracket (201) is connected to the backrest transverse drive mechanism (3). The rotatable connection between the first bracket (200) and the second bracket (201) is the rotation center of the backrest (1).

5. A method for adaptive adjustment of the backrest rotation center according to any one of claims 1-3, characterized in that, There are two backrest rotating brackets (2), which are connected to the left and right sides of the backrest (1) respectively.

6. The method for adaptive adjustment of the backrest rotation center according to claim 5, characterized in that, There are also two backrest lateral movement drive mechanisms (3), which are connected to two backrest rotation brackets (2) respectively.

7. A method for adaptive adjustment of the backrest rotation center according to any one of claims 1-3, characterized in that, The lower end of the backrest (1) is connected to the main body of the seat by an elastic reset mechanism (4).

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