Exoskeleton gravity balance mechanism

Abstract

The application provides an exoskeleton gravity balance mechanism for matching an exoskeleton device to improve the balance performance of the exoskeleton device, comprising: a base, an output bearing is arranged in the middle of the base, a baffle, a spring and an auxiliary pulley are arranged on the base, one end of the spring is fixedly connected with the base, and the other end is connected with one side of the baffle; an X-shaped balance unit is installed on the base through the output bearing, comprising a driving rod module, an adjustable module and a plurality of pulleys, the driving rod module comprises an output shaft and a driving rod body, the adjustable module is fixed on the base, and the adjustable module can control the position of the pulleys; a front cover is arranged above the X-shaped balance unit and is fixedly connected with the base, a hole for passing through the output shaft is arranged in the middle of the front cover; a rope is fixed at one end of the pulley of the X-shaped balance unit, passes through other pulleys, and is connected with the other side of the baffle at the other end, so that the elongation of the spring can be adjusted by adjusting the position of the pulley, and the balanced gravity can be changed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of exoskeleton gravity balance mechanism, and in particular to an exoskeleton gravity balance mechanism. BACKGROUND

[0002] Gravity balance technology refers to that a balanced object can be kept in a static state at any position in a workspace with the help of certain specific mechanisms, that is, the gravity balance mechanism can provide a torque to eliminate the gravity torque generated by the balanced object, and is independent of the motion state. According to the above definition, gravity balance is essentially a conversion of energy, that is, the potential energy is conserved in the system composed of the gravity balance mechanism and the balanced object, and thus the condition of gravity balance can be derived to guide the design of the gravity balance mechanism. In summary, if the gravity balance mechanism is applied to a mechanical device, unnecessary energy waste can be avoided.

[0003] Exoskeleton device refers to a wearable mechanical device that has the function of enhancing human ability and is widely used in medical rehabilitation, logistics transportation, military and other occasions. According to whether a power source is used, the exoskeleton can be divided into active and passive types. In order to realize the function of ability enhancement, the exoskeleton usually needs to combine with gravity balance technology to convert energy. For passive exoskeleton, it usually has fixed balance ability, which limits its application range.

[0004] The Chinese invention patent with application number 202310944450.5 discloses an exoskeleton gravity balance mechanism, which adopts a symmetrical structure and outputs elastic potential energy based on a rope-pulley-spring unit to compensate the gravity torque of the human upper limb. The mechanism can adapt to different gravity compensation requirements by adjusting the tension of the spring. Since the mechanism uses a spring as an energy storage element, and the balance ability of the mechanism is controlled by adjusting the tension of the spring, the adjustment of the spring is limited (the elongation of the spring cannot exceed the maximum value). The present application indirectly changes the elongation of the spring by adjusting the position of the pulley, that is, it can be applied to different balanced objects.

[0005] The Chinese invention patent with application number 201710332514.0 discloses a gravity balance mechanism for upper limb rehabilitation exoskeleton. By introducing the gravity balance mechanism, the second joint driving torque of the upper limb rehabilitation exoskeleton can be greatly reduced. The device uses a pulley set to reduce the tensile deformation of the spring, and at the same time, increases an adjustable fixed unit to control the initial tensile deformation of the spring, so that the gravity balance mechanism has a larger balance range. Adjusting the initial tensile deformation of the spring can only change the balance range of the mechanism, but cannot improve the balance performance of the mechanism.

[0006] Therefore, the technical problem to be solved at present is how to improve the performance of gravity balance and expand the balance range of the mechanism while being applicable to different objects to be balanced. SUMMARY

[0007] The present application is made to solve the above problems, and aims to provide an exoskeleton gravity balance mechanism.

[0008] The present application provides an exoskeleton gravity balance mechanism for matching an exoskeleton device to improve the balance performance of the exoskeleton device, which has the following features: a base, a through hole is formed in the middle of the base, an output bearing is arranged in the through hole, an arc-shaped notch is arranged on the side of the base, a baffle, a spring and an auxiliary pulley are arranged on the base, one end of the spring is fixedly connected to the base, and the other end is connected to one side of the baffle; an X-shaped balance unit is installed on the base through the output bearing, and includes a driving rod module, an adjustable module and a plurality of pulleys, the driving rod module includes an output shaft and a driving rod body, the output shaft is fixedly connected to the driving rod body, the output shaft penetrates the base and the X-shaped balance unit, and is connected to the exoskeleton device, the output shaft rotates under the drive of the exoskeleton device, pulleys are arranged at both ends of the driving rod body, the both ends of the driving rod body can rotate along the arc-shaped notch, the adjustable module is fixed to the base, pulleys are arranged at both ends of the adjustable module, and the position of the pulleys can be controlled by the adjustable module; a front cover is arranged above the X-shaped balance unit and is fixedly connected to the base, a hole is formed in the middle of the front cover for the output shaft to pass through; a rope is fixed to a pulley of the X-shaped balance unit at one end, passes through other pulleys, and is connected to the other side of the baffle at the other end, so that the elongation of the spring can be adjusted by adjusting the position of the pulleys, and the balanced gravity can be changed.

[0009] In the exoskeleton gravity balance mechanism provided by the present application, the base can be further provided with a hollow rectangular block with one side open, the baffle is arranged in the middle of the block, and the both ends of the baffle are slidably connected to the block, so that the baffle can slide in the block.

[0010] In the exoskeleton gravity balance mechanism provided by the present application, the pulleys can further include rotating pulleys and fixed pulleys, the rotating pulleys are arranged on the driving rod body, and the fixed pulleys are arranged on the adjustable module, the number of the rotating pulleys and the fixed pulleys is an integer multiple of 2.

[0011] In the exoskeleton gravity balance mechanism provided by the present application, the fixed pulleys can be represented by the letter A i , the rotating pulleys can be represented by the letter B i , the total number of the pulleys is 2n, the first pulley is defined as A0, the last pulley is defined as A n , and The rope winding mode is "arch" shape, that is, from the pulley A0, in turn through B0, B1, A1, A2, B2... B n-2 , A n-2 , A n-1 , B n-1 , B n , A n .

[0012] The gravity balance is the process of energy conversion. According to the principle of energy conservation, the elastic potential energy of the spring and the gravitational potential energy of the balanced object are constant, that is,

[0013]

[0014] Where G represents the gravity of the balanced object, L represents the distance between the center of the balanced object and the rotation center, K represents the stiffness of the spring, a represents the rotation angle of the balanced object, and Δx represents the elongation of the spring. The expression is as follows,

[0015]

[0016] The essence of the X-type balance unit is to amplify based on the initial elongation Δx, so Δx = l0 is defined. After the action of the X-type balance unit, the elongation of the spring is And

[0017]

[0018] Here, the proportion factor t is positive. Note that Δx is a function of the rotation angle a, so in order to satisfy equation (3), any rope segment l i is proportional to l0 at any rotation angle a, and each rope segment is parallel to each other, that is, A0B0∥A1B1∥...∥A n-1 B n-1 ∥A n B n , define

[0019]

[0020] Obviously, y i is the proportion of each rope segment l i to l0,

[0021] The design process of the X-type balance unit is as follows,

[0022] 1) Select the proportion factor t;

[0023] 2) Determine y i under the premise of satisfying equation (3);

[0024] Select parameters a and b, and calculate l i .

[0025] In the exoskeleton gravity balance mechanism provided by the application, the pulleys can be four, including a left rotating pulley, a right rotating pulley, a left fixed pulley and a right fixed pulley.

[0026] In the exoskeleton gravity balance mechanism provided by the application, the adjustable module can include an optical axis, a double-rotation screw rod and a knob, the double-rotation screw rod includes a left-rotation screw rod and a right-rotation screw rod fixedly connected, the left-rotation screw rod and the right-rotation screw rod are respectively provided with a left nut and a right nut, the left nut and the right nut are respectively fixed with a left sliding block and a right sliding block, the left sliding block and the right sliding block are movably connected with the optical axis, the left sliding block and the right sliding block are respectively provided with a left fixed pulley and a right fixed pulley, and the knob is fixedly connected with the double-rotation screw rod and used to drive the double-rotation screw rod to rotate, so as to control the left fixed pulley and the right fixed pulley to move towards each other or in opposite directions.

[0027] In the exoskeleton gravity balance mechanism provided by the application, the rope can be wound in the following way: taking the left rotating pulley as a starting point, passing through the left fixed pulley, the right fixed pulley, the right rotating pulley, the output bearing and the auxiliary pulley, and finally being connected with the baffle, when the pulleys are four, the rope winding is a special case of the "arch" shape, and because the fixed pulleys and the rotating pulleys are symmetrically arranged, the rope segment between the left rotating pulley and the left fixed pulley is parallel to the rope segment between the right rotating pulley and the right fixed pulley, meeting the requirement of formula (4).

[0028] In the exoskeleton gravity balance mechanism provided by the application, the number of pulleys can be greater than four, when adjusting the position of the pulleys, the moving speed of the pulleys on the same side needs to be considered in order to meet formula (4), and when no adjustment is made, formula (7) is met.

[0029]

[0030] After the position of the pulleys is adjusted, the following conclusions are theoretically true,

[0031]

[0032] According to formulas (5) and (6), the moving distance of the pulleys meets formula (8).

[0033]

[0034] Formula (7) shows that the moving distance between the same side pulleys on the adjustable module is proportional, the adjustable module includes an optical axis, a double-rotation screw rod and a knob, the double-rotation screw rod is composed of screw rods with different leads, and the proportional relationship between the leads satisfies formula (7), and the knob is fixedly connected with the double-rotation screw rod.

[0035] In the exoskeleton gravity balance mechanism provided by the application, the rope can be made of nylon or steel.

[0036] In the exoskeleton gravity balance mechanism provided by the application, the adjustable module can also be arranged on the main rod body, so that the position of the pulley on the main rod body can be controlled.

[0037] Effects of the application

[0038] Compared with the traditional rope-pulley unit, the exoskeleton gravity balance mechanism provided by the application can improve the balancing ability of the mechanism without changing the motion characteristics of the balanced object, that is, the application range of the mechanism is expanded.

[0039] The general gravity balance module can only be applied to specific balanced objects, and the spring stiffness needs to be recalculated or the structure of the gravity balance module needs to be modified for different balanced objects. The adjustable module designed in the application can conveniently and quickly adjust the position of the pulley, so that it can adapt to different balanced objects.

[0040] In the traditional exoskeleton device, the balancing unit is generally integrated with the exoskeleton body and is not easy to maintain. The application adopts a modular design and can be conveniently combined with the exoskeleton device, and is easy to replace and maintain. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a structure diagram of the X-shaped balancing unit in embodiment 1 of the application;

[0042] Figure 2 is a front side view of the exoskeleton gravity balance module in embodiment 1 of the application;

[0043] Figure 3 is a rear side view of the exoskeleton gravity balance module in embodiment 1 of the application;

[0044] Figure 4 is a structure diagram of the X-shaped balancing unit with pulley arrangement in embodiment 1 of the application;

[0045] Figure 5 is a structure diagram of the adjustable module in embodiment 1 of the application;

[0046] Figure 6is a schematic structural diagram of the active rod in Example 1 of the present invention;

[0047] Figure 7 is a simplified structural diagram of an X-shaped balancing unit in a multi-pulley configuration in Example 1 of the present invention; and

[0048] Figure 8 2 is a schematic structural diagram of a multi-lead screw in Example 2 of the present invention. DETAILED DESCRIPTION

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0050] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the following embodiments and accompanying drawings will specifically illustrate the exoskeleton gravity balancing mechanism of the present invention.

[0051] Example 1

[0052] Figure 1 1 is a simplified structural diagram of an X-type balancing unit in an embodiment of the present invention. Figure 2 2 is a front side view of an exoskeleton gravity balance module according to an embodiment of the present invention. Figure 3 2 is a rear side view of an exoskeleton gravity balance module according to an embodiment of the present invention. Figure 4 2 is a schematic structural diagram of an X-shaped balancing unit with a pulley configuration in an embodiment of the present invention. Figure 5 It is a structural diagram of the adjustable module in Example 1 of the present invention. Figure 6 Schematic diagram of the structure of the active rod in Example 1 of the present invention.

[0053] like Figures 1-6 As shown, the exoskeleton gravity balancing mechanism 100 in this embodiment is used to cooperate with the exoskeleton device to improve the balance performance of the exoskeleton device, and includes a base 20, an X-shaped balancing unit 30, a front cover 10 and a rope 50.

[0054] An output bearing 21 is provided through the middle of the base 20, an arc-shaped notch 26 is provided on the circumference of the base 20, a baffle 23, a spring 25 and an auxiliary pulley 24 are provided on the base 20, one end of the spring 25 is fixedly connected to the base 20, and the other end is connected to one side of the baffle 23.

[0055] The base 20 is provided with a hollow rectangular block 22 with one side opening, and a baffle 23 is arranged in the middle of the block 22, and the baffle 23 is slidably connected with the block 22 at both ends, so that the baffle 23 can slide inside the block 22.

[0056] As shown in the drawings, the X-shaped balancing unit 30 is installed on the base 20 through the output bearing 21, and includes a driving rod module 31, an adjustable module 32, and a plurality of pulleys. Figures 4-6

[0057] The pulleys are four, including a left rotating pulley 37, a right rotating pulley 38, a left fixed pulley 44, and a right fixed pulley 45. The rotating pulleys are located on the driving rod body 34, and the fixed pulleys are located on the adjustable module 32. The number of rotating pulleys and fixed pulleys is two.

[0058] The driving rod module 31 includes an output shaft 33 and a driving rod body 34, and the output shaft 33 is fixedly connected with the driving rod body 34. The output shaft 33 penetrates the base 20 and the X-shaped balancing unit 30, and is connected with an exoskeleton device. The output shaft 33 rotates under the drive of the exoskeleton device. The two ends of the driving rod body 34 are respectively provided with a left mounting hole 35 and a right mounting hole 36, which are used for mounting pulleys. The pulleys are connected with the driving rod body 34 through link bolts. The two ends of the driving rod body 34 can rotate along the arc-shaped notch 26, and the driving rod body 34 is of a hollow structure.

[0059] The adjustable module 32 is fixed on the base 20, and the two ends of the adjustable module 32 are respectively provided with fixed pulleys. The adjustable module 32 can control the position of the fixed pulleys. By adjusting the position of the pulleys, the balanced gravity can be changed.

[0060] The adjustable module 32 includes an optical axis 41, a double-rotation screw rod 40, and a knob 39.

[0061] The double-rotation screw rod 40 is connected with the base 20 through the output bearing 21 and can rotate freely. The axes of the double-rotation screw rod 40 and the optical axis 41 are parallel to each other. The double-rotation screw rod 40 includes a left-handed screw rod and a right-handed screw rod which are fixedly connected.

[0062] The left-handed screw rod and the right-handed screw rod are respectively provided with a left nut 42 and a right nut 43. The left nut 42 and the right nut 43 are respectively fixed with a left sliding block 46 and a right sliding block 47 through bolts. The left sliding block 46 and the right sliding block 47 are respectively provided with a sliding block notch and a sliding block through hole. The sliding block notch is used to connect the left nut 42 and the right nut 43, and the sliding block through hole is used to pass through the optical axis 41, so that the left sliding block 46 and the right sliding block 47 are movably connected with the optical axis 41. The left sliding block 46 and the right sliding block 47 are respectively provided with a left fixed pulley 44 and a right fixed pulley 45. ​

[0063] The left nut 42, the left slider 46, the slider notch and the slider through hole on the left-handed screw rod are in a mirror image relationship with the right nut 43, the right slider 47, the slider notch and the slider through hole on the right-handed screw rod.

[0064] The knob 39 is fixedly connected with the double-rotation screw rod 40, and is used to drive the double-rotation screw rod 40 to rotate, so as to control the left fixed pulley 44 and the right fixed pulley 45 to move towards or reversely.

[0065] The front cover 10 is arranged above the X-shaped balancing unit 30 and is fixedly connected with the base 20. A hole for passing through the output shaft 33 is arranged in the middle of the front cover 10.

[0066] One end of the rope 50 is fixed to the pulley of the X-shaped balancing unit 30, passes through other pulleys, and the other end is connected with the other side of the baffle 23, so that the elongation of the spring 25 can be adjusted by adjusting the position of the pulley, the balanced gravity is changed, and the rope 50 is made of nylon or steel.

[0067] The fixed pulley is denoted by the letter A i , the rotating pulley is denoted by B i , the total number of pulleys is 2n, the first pulley is defined as A0, and the terminal pulley is defined as A n , and The winding mode of the rope is in the shape of a “bow”, that is, starting from the pulley A0, sequentially passing through B0, B1, A1, A2, B2……B n-2 , A n-2 , A n-1 , B n-1 , B n , A n .

[0068] The gravity balance is a process of energy conversion. According to the principle of energy conservation, the elastic potential energy of the spring 25 and the gravitational potential energy of the balanced object are constant, that is,

[0069]

[0070] Wherein, G represents the gravity of the balanced object, L represents the distance between the center of the balanced object and the rotation center, K represents the stiffness of the spring 25, α represents the rotation angle of the balanced object, and Δx represents the elongation of the spring 25. The expression is as follows,

[0071]

[0072] The essence of the X-shaped balancing unit 30 is to amplify based on the initial elongation Δx, so Δx = l0, and the elongation of the spring 25 after the action of the X-shaped balancing unit 30 is and

[0073]

[0074] Here the proportion factor t is positive, and it is noted that Δx is a function of the rotation angle α, so as to satisfy equation (3), any one rope 50 segment l i At any rotation angle α, it is proportional to l0, and each rope 50 segment is parallel to each other, i.e. A0B0||A1B1||...||A n-1 B n-1 ||A n B n , and it is defined that

[0075]

[0076] Obviously, y i is proportional to l i 0,

[0077] The design process of the X-shaped balancing unit 30 is as follows,

[0078] 3) Select the proportion factor t;

[0079] 4) Determine y i under the premise of satisfying equation (3);

[0080] 5) Select parameters a and b, and calculate l i .

[0081] The winding mode of the rope 50 is as follows: starting from the left rotating pulley 37, passing through the left fixed pulley 44, the right fixed pulley 45, the right rotating pulley 38, the output bearing 21, the auxiliary pulley 24, and finally connecting with the baffle 23. When there are four pulleys, the winding of the rope 50 is a special case of "arch" shape. Since the fixed pulleys and the rotating pulleys are symmetrically arranged, the rope 50 segment between the left rotating pulley 37 and the left fixed pulley 44 is parallel to the rope 50 segment between the right rotating pulley 38 and the right fixed pulley 45, satisfying the requirement of equation (4).

[0082] Proof of the lifting gravity balancing ability of the X-shaped balancing unit 30:

[0083] The stiffness of the spring 25 is K=GL / ab, where G represents the gravity of the object to be balanced, L represents the distance from the center of gravity of the object to be balanced to the center of the first rotating pair, and a and b represent the distances from the outermost fixed pulley and the outermost rotating pulley to the center of the first rotating pair, respectively. The elastic potential energy of the spring 25 is By transforming this equation, we have where t is the proportion factor.

[0084] Therefore, when the X-shaped balancing unit 30 is used, the deformation of the spring 25 becomes The stiffness of the spring 25 will become If the stiffness of the spring 25 is not changed, the weight of the balanced object will become tG according to the expression of the stiffness of the spring 25. The above conclusion shows that the X-type balancing unit 30 improves the ability of gravity balance.

[0085] The use method and principle of the present application are as follows:

[0086] (1) According to different types of exoskeleton devices, rotate the knob 39 to control the fixed pulley on the double-rotation screw rod 40 to move towards or reverse, and adjust to the appropriate position;

[0087] (2) Adjust the position of the auxiliary pulley 24 on the base 20 to adjust to the appropriate position;

[0088] (3) Rotate the exoskeleton device drive output bearing 21, and the output bearing 21 drives the driving rod body 34 in the X-type balancing unit 30 to rotate. At this time, the distance between the rotating pulley and the fixed pulley is lengthened, the rope 50 stretches the spring 25, and the spring 25 is stretched to adjust the pulling length of the rope 50 based on the elastic force, thereby controlling the range of rotation of the driving rod body 34 and balancing the exoskeleton device.

[0089] Example Two

[0090] Figure 7 is a structural diagram of the X-type balancing unit 30 in Example 1 of the present application with a multi-pulley configuration.

[0091] As Figure 7 shown, when the number of pulleys is greater than four, the moving speed of the pulleys on the same side needs to be considered when adjusting the position of the pulleys to satisfy formula (4). When no adjustment is made, then,

[0092]

[0093] After adjusting the position of the pulleys, the following conclusions are theoretically true,

[0094]

[0095] Combining formulas (5) and (6), it can be obtained that the moving distance of the pulleys satisfies,

[0096]

[0097] Formula (7) shows that the moving distance between the pulleys on the same side on the adjustable module 32 is in a proportional relationship.

[0098] The rope 50 is wound in the shape of a "bow" on the pulleys, and the rope 50 forms rope 50 segments l iThe lengths of the rope segments 50 are parallel to each other, and the sum of the lengths of the rope segments 50 is wherein n represents the number of the rope segments 50, and Δx represents the length of the rope segment 50 between the fixed pulley and the rotating pulley when n = 2.

[0099] Figure 8 is a structural schematic diagram of a multi-lead screw in Embodiment 2 of the present application.

[0100] As shown in Figure 8 , the adjustable module 32 comprises an optical axis 41, a double-rotation-direction screw 40 and a knob 39, the double-rotation-direction screw 40 is composed of screw connection groups with different leads, and at least comprises a first lead 48 and a second lead 49, the proportional relationship between the leads satisfies formula (7), and the knob 39 is fixedly connected with the double-rotation-direction screw 40.

[0101] For the convenience of expression, the same symbols are given to the same structures in the present embodiment as in Embodiment 1, and the same descriptions are omitted.

[0102] Embodiment Three

[0103] The adjustable module 32 is also arranged on the active rod body 34, so that the position of the rotating pulley on the active rod body 34 can be controlled, and the rotating pulley moves in the same direction or in the opposite direction.

[0104] For the convenience of expression, the same symbols are given to the same structures in the present embodiment as in Embodiment 1, and the same descriptions are omitted.

[0105] Effects of the Embodiment

[0106] Compared with the traditional rope-pulley unit, the exoskeleton gravity balance mechanism according to the present application can improve the balancing ability of the mechanism without changing the motion characteristics of the balanced object, that is, the application range of the mechanism is expanded.

[0107] Generally, the gravity balance module can only be applied to a specific balanced object, and the spring stiffness needs to be recalculated or the structure of the gravity balance module needs to be modified for different balanced objects. The adjustable module designed in the present application can conveniently and quickly adjust the position of the pulley, so that it can adapt to different balanced objects.

[0108] In the traditional exoskeleton device, the balance unit is generally designed to be integrated with the exoskeleton body, which is not easy to maintain. The present application adopts a modular design, which can be conveniently combined with the exoskeleton device and is easy to replace and maintain.

[0109] The auxiliary pulley of the application is used to change the direction of the rope, so that the spring connected therewith can be installed in a proper position, the position of the auxiliary pulley can be flexibly adjusted, the overall structure is more compact, and the balance performance of the exoskeleton gravity balance mechanism is improved.

[0110] The application adjusts the pulley position through the adjustable module, thereby changing the balanced gravity, combines the unique pulley arrangement and the rope winding mode of the X-shaped balance unit, improves the performance of the exoskeleton gravity balance module, and expands the application range.

[0111] Those skilled in the art should understand that the application is not limited to the above-mentioned embodiments, the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the application, various changes and improvements can be made without departing from the spirit and scope of the application, and these changes and improvements all fall within the scope of the claimed application. The scope of protection of the application is defined by the appended claims and their equivalents.

Claims

1. An exoskeleton gravity balancing mechanism, used to cooperate with an exoskeleton device to improve the balance performance of the exoskeleton device, characterized in that: include: A base, wherein an output bearing is provided through the middle of the base, an arc-shaped notch is provided on the circumference of the base, a baffle, a spring and an auxiliary pulley are provided on the base, one end of the spring is fixedly connected to the base, and the other end is connected to one side of the baffle; An X-shaped balancing unit is mounted on the base via the output bearing, and includes an active rod module, an adjustable module, and a plurality of pulleys. The active rod module includes an output shaft and an active rod body. The output shaft is fixedly connected to the active rod body, passes through the base and the X-shaped balancing unit, and is connected to the exoskeleton device. The output shaft rotates when driven by the exoskeleton device. The pulleys are respectively provided at both ends of the active rod body. Both ends of the active rod body can rotate along the arc-shaped slot. The adjustable module is fixed to the base. The pulleys are respectively provided at both ends of the adjustable module. The adjustable module can control the position of the pulleys. A front cover is provided above the X-shaped balancing unit and is fixedly connected to the base, and a hole is provided in the middle of the front cover for passing the output shaft; A rope, one end of which is fixed to the pulley of the X-shaped balancing unit, passes around the other pulleys, and the other end is connected to the other side of the baffle, so that the elongation of the spring can be adjusted by adjusting the position of the pulley to change the balanced gravity.

2. The exoskeleton gravity balancing mechanism according to claim 1, characterized in that: in, A hollow rectangular stopper with one side open is provided on the base, the baffle is provided in the middle of the stopper, and both ends of the baffle are slidably connected to the stopper so that the baffle can slide inside the stopper.

3. The exoskeleton gravity balancing mechanism according to claim 1, characterized in that: in, The pulley includes a rotating pulley and a fixed pulley, the rotating pulley is located on the active rod body, and the fixed pulley is located on the adjustable module. The number of the rotating pulleys and the fixed pulleys is an integer multiple of 2.

4. The exoskeleton gravity balancing mechanism according to claim 3, characterized in that: in, The fixed pulley is marked with the letter A i Indicates that the rotating pulley is B i Indicates that the total number of pulleys is 2n, the first pulley is defined as A0, the end pulley is defined as A n ,and The rope is wound in a bow shape, starting from pulley A0 and passing through B0, B1, A1, A2, B2...B n-2 、A n-2 、A n-1 、B n-1 、B n 、A n , Gravitational balance is a process of energy conversion. According to the principle of conservation of energy, the sum of the elastic potential energy of the spring and the gravitational potential energy of the object being balanced remains unchanged, that is, Where G represents the gravity of the object being balanced, L represents the distance between the center of the object being balanced and the center of rotation, K represents the stiffness of the spring, α represents the rotation angle of the object being balanced, and Δx represents the elongation of the spring. The expression is as follows: The essence of the X-shaped balancing unit is to amplify the initial elongation Δx, so Δx=l0 is defined. After the action of the X-shaped balancing unit, the elongation of the spring is and Here the proportional factor t is a positive number. Note that Δx is a function of the rotation angle α. Therefore, in order to satisfy Equation (3), any rope segment l i At any rotation angle α, it is proportional to l0, and the rope segments are parallel to each other, that is, A0B0∥A1B1∥...∥A n-1 B n-1 ∥A n B n ,definition Obviously, i Each rope segment l i The ratio to l0, The design process of the X-type balancing unit is as follows: 1) Select the scaling factor t; 2) Under the premise of satisfying formula (3), determine y i ; 3) Select parameters a and b and calculate l i .

5. The exoskeleton gravity balancing mechanism according to claim 4, characterized in that: in, There are four pulleys, including a left rotating pulley, a right rotating pulley, a left fixed pulley and a right fixed pulley.

6. The exoskeleton gravity balancing mechanism according to claim 5, characterized in that: in, The adjustable module includes an optical axis, a double-rotation screw and a knob, the double-rotation screw includes a left-rotation screw and a right-rotation screw fixedly connected, the left-rotation screw and the right-rotation screw are respectively provided with a left nut and a right nut, the left nut and the right nut are respectively fixed with a left slider and a right slider, the left slider and the right slider are movably connected to the optical axis, the left slider and the right slider are respectively provided with a left fixed pulley and a right fixed pulley, the knob is fixedly connected to the double-rotation screw, for driving the double-rotation screw to rotate, thereby controlling the left fixed pulley and the right fixed pulley to move toward or in the opposite direction.

7. The exoskeleton gravity balancing mechanism according to claim 6, characterized in that: in, The rope is wound in the following manner: starting from the left rotating pulley, the rope passes through the left fixed pulley, the right fixed pulley, the right rotating pulley, the output bearing, the auxiliary pulley, and finally connected to the baffle. When there are four pulleys, the rope winding is a special case of a "bow" shape. Since the fixed pulley and the rotating pulley are symmetrically arranged, the rope segment between the left rotating pulley and the left fixed pulley is parallel to the rope segment between the right rotating pulley and the right fixed pulley, satisfying the requirements of formula (4).

8. The exoskeleton gravity balancing mechanism according to claim 4, characterized in that: in, The number of pulleys is greater than four. When adjusting the pulley position, in order to satisfy formula (4), it is necessary to consider the moving speed of the pulley on the same side. When no adjustment is made, then, After the pulley position is adjusted, the following conclusions are theoretically established: Combining formulas (5) and (6), we can get that the moving distance of the pulley satisfies, Formula (7) shows that the moving distances between the pulleys on the same side of the adjustable module are proportional. The adjustable module includes an optical axis, a dual-rotation screw and a knob. The dual-rotation screw is composed of screws with different leads. The proportional relationship between the leads satisfies formula (7). The knob is fixedly connected to the dual-rotation screw.

9. The exoskeleton gravity balancing mechanism according to claim 1, characterized in that: in, The rope is made of nylon or steel.

10. The exoskeleton gravity balancing mechanism according to claim 1, characterized in that: in, The active rod body is also provided with the adjustable module, so as to control the position of the pulley on the active rod body.

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