Exoskeleton gravity balance mechanism

Abstract

The invention provides an exoskeleton gravity balance mechanism which is used for being matched with an exoskeleton device to improve the balance performance of the exoskeleton device and comprises a base, an output bearing is arranged in the middle of the base in a penetrating mode, 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 of the spring is connected with one side of the baffle; the X-type balance unit is installed on the base through an output bearing and comprises 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, and the adjustable module is fixed to the base and can control the positions of the pulleys; the front cover is arranged above the X-shaped balance unit and fixedly connected with the base, and a hole for the output shaft to penetrate through is formed in the middle of the front cover; one end of the rope is fixed on the pulley of the X-shaped balance unit and bypasses other pulleys, and the other end of the rope is connected with the other side of the baffle, so that the elongation of the spring can be adjusted by adjusting the position of the pulley, and the balanced gravity is changed.

Description

Technical Field

[0001] The invention relates to the field of exoskeleton gravity balancing mechanisms, and in particular to an exoskeleton gravity balancing mechanism. Background Art

[0002] Gravity balancing technology refers to the use of certain specific mechanisms to keep the object being balanced stationary at any position in the workspace, that is, the gravity balancing mechanism can provide torque to eliminate the gravity torque generated by the object being balanced, and it is independent of the state of motion. According to the above definition, gravity balance is essentially the conversion of energy, that is, the potential energy is conserved in the system composed of the gravity balancing mechanism and the object being balanced. From this, the conditions for gravity balance can be derived, thereby guiding the design of the gravity balancing mechanism. In summary, if the gravity balancing mechanism is applied to a mechanical device, unnecessary energy waste can be avoided.

[0003] An exoskeleton is a wearable mechanical device that has the function of enhancing human capabilities and is widely used in medical rehabilitation, logistics, transportation, military and other occasions. Depending on whether a power source is used, exoskeletons can be divided into active and passive types. In order to achieve the function of enhancing capabilities, exoskeletons usually need to be combined with gravity balancing technology to perform energy conversion. For passive exoskeletons, they usually have a fixed balance ability, which limits their scope of application.

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

[0005] The Chinese invention patent with application number 201710332514.0 discloses a gravity balancing mechanism for an upper limb rehabilitation exoskeleton. By introducing a gravity balancing mechanism, the device can significantly reduce the second joint driving torque of the upper limb rehabilitation exoskeleton. The device uses a pulley set to reduce the tensile deformation of the spring. At the same time, by adding an adjustable fixing unit to control the initial tensile deformation of the spring, the gravity balancing 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 that needs to be solved urgently is how to improve the performance of gravity balance, apply it to different balanced objects, and expand the balance range of the mechanism. Summary of the invention

[0007] The present invention is made to solve the above-mentioned problems, and its purpose is to provide an exoskeleton gravity balancing mechanism.

[0008] The present invention provides an exoskeleton gravity balancing mechanism, which is used to cooperate with an exoskeleton device to improve the balancing performance of the exoskeleton device, and has the following characteristics: a base, an output bearing is arranged through the middle of the base, an arc-shaped notch is arranged on the circumference 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 balancing unit is installed on the base through the output bearing, and comprises an active rod module, an adjustable module and a plurality of pulleys, the active rod module comprises an output shaft and an active rod body, the output shaft is fixedly connected to the active rod body, the output shaft passes through the base and the X-shaped balancing unit, and is connected to the The two ends of the active rod body are respectively provided with pulleys, and the two ends of the active rod body can rotate along the arc groove. The adjustable module is fixed on the base, and the two ends of the adjustable module are respectively provided with pulleys, and the adjustable module can control the position of the pulley; the front cover is arranged above the X-shaped balancing unit and is fixedly connected to the base, and a hole for passing the output shaft is opened in the middle of the front cover; the rope, one end of the rope is fixed on the pulley of the X-shaped balancing unit, bypassing 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.

[0009] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: a hollow rectangular block with an opening on one side is provided on the base, a baffle is provided in the middle of the block, and both ends of the baffle are slidably connected to the block so that the baffle can slide inside the block.

[0010] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: wherein the pulley includes a rotating pulley and a fixed pulley, the rotating pulley is located on the active rod body, the fixed pulley is located on the adjustable module, and the number of the rotating pulley and the fixed pulley are both integer multiples of 2.

[0011] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: wherein the fixed pulley is represented by the letter A i Indicates that the rotating pulley is B i Indicates that the total number of pulleys is 2n, and the first pulley is defined as A0 and the end pulley is A n ,and The rope is wound in a bow shape, starting from pulley A0, passing through B0, B1, A1, A2, B2...B n-2 , A n-2 , A n-1 , B n-1 , B n , A n .

[0012] 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,

[0013]

[0014] Among them, 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:

[0015]

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

[0017]

[0018] 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

[0019]

[0020] Obviously, i Each rope segment l i The ratio to l0,

[0021] The design process of the X-type balancing unit is as follows:

[0022] 1) Select the scaling factor t;

[0023] 2) Under the premise of satisfying formula (3), determine y i ;

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

[0025] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: wherein, there are four pulleys, including a left rotating pulley, a right rotating pulley, a left fixed pulley and a right fixed pulley.

[0026] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: wherein, 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, and is used to drive 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.

[0027] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: wherein the rope is wound in the following manner, starting from the left rotating pulley, passing 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 the "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).

[0028] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following features: wherein the number of pulleys is greater than four, when adjusting the pulley position, in order to satisfy equation (4), the moving speed of the pulley on the same side needs to be considered. When no adjustment is performed, then,

[0029]

[0030] After the pulley position is adjusted, the following conclusions are theoretically established:

[0031]

[0032] Combining formulas (5) and (6), we can get that the moving distance of the pulley satisfies,

[0033]

[0034] 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.

[0035] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following feature: wherein the rope is made of nylon or steel.

[0036] The exoskeleton gravity balancing mechanism provided by the present invention may also have the following feature: wherein an adjustable module is also provided on the active rod body, so as to be able to control the position of the pulley on the active rod body.

[0037] Functions and Effects of the Invention

[0038] According to the exoskeleton gravity balancing mechanism involved in the present invention, compared with the traditional rope-pulley unit, the present invention can improve the balancing ability of the mechanism without changing the movement characteristics of the balanced object, that is, expand the application range of the mechanism.

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

[0040] In a conventional exoskeleton device, the balance unit is generally integrated with the exoskeleton body, which is not easy to maintain. The present invention adopts a modular design, which can be conveniently combined with the exoskeleton device and is easy to replace and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a simplified structural diagram of an X-type balancing unit in Embodiment 1 of the present invention;

[0042] Figure 2 is a front side view of the exoskeleton gravity balance module in Example 1 of the present invention;

[0043] Figure 3 is a rear side view of the exoskeleton gravity balance module in Example 1 of the present invention;

[0044] Figure 4 is a schematic structural diagram of an X-shaped balancing unit under a pulley configuration in Embodiment 1 of the present invention;

[0045] Figure 5 is a schematic diagram of the structure of the adjustable module in Embodiment 1 of the present invention;

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

[0048] Figure 8 It is a schematic structural diagram of the 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 clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

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

[0051] Embodiment 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 is a front side view of an exoskeleton gravity balance module in an embodiment of the present invention. Figure 3 is a rear side view of an exoskeleton gravity balance module in an embodiment of the present invention. Figure 4 Schematic diagram of the structure of an X-shaped balancing unit under a pulley configuration in an embodiment of the present invention. Figure 5 It is a schematic diagram of the structure of the adjustable module in Example 1 of the present invention. Figure 6 It is a schematic structural diagram of the active rod in Example 1 of the present invention.

[0053] like Figure 1-6 As shown, the exoskeleton gravity balancing mechanism 100 in this embodiment is used to cooperate with the exoskeleton device to improve the balancing 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] A hollow rectangular stopper 22 with one side open is disposed on the base 20 , a baffle 23 is disposed in the middle of the stopper 22 , and both ends of the baffle 23 are slidably connected to the stopper 22 , so that the baffle 23 can slide inside the stopper 22 .

[0056] like Figure 4-6 As shown, the X-shaped balancing unit 30 is mounted on the base 20 via the output bearing 21 , and includes an active rod module 31 , an adjustable module 32 and a plurality of pulleys.

[0057] There are four pulleys, 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 active rod body 34, and the fixed pulleys are located on the adjustable module 32. The number of rotating pulleys and fixed pulleys is two each.

[0058] The active rod module 31 includes an output shaft 33 and an active rod body 34. The output shaft 33 is fixedly connected to the active rod body 34. The output shaft 33 passes through the base 20 and the X-shaped balancing unit 30 and is connected to the exoskeleton device. The output shaft 33 rotates when driven by the exoskeleton device. The two ends of the active rod body 34 are respectively provided with a left mounting hole 35 and a right mounting hole 36. The left mounting hole 35 and the right mounting hole 36 are respectively used to install pulleys. The pulleys are connected to the active rod body 34 through connecting bolts. The two ends of the active rod body 34 can rotate along the arc-shaped slot 26. The active rod body 34 is a hollow structure.

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

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

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

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

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

[0064] The knob 39 is fixedly connected to the double-rotation screw 40 and is used to drive the double-rotation screw 40 to rotate, thereby controlling the left fixed pulley 44 and the right fixed pulley 45 to move towards or in opposite directions.

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

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

[0067] Fixed pulley with letter A i Indicates that the rotating pulley is B i Indicates that the total number of pulleys is 2n, and the first pulley is defined as A0 and the end pulley is A n ,and The rope is wound in a bow shape, starting from pulley A0, passing through B0, B1, A1, A2, B2...B n-2 , A n-2 , A n-1 , B n-1 , B n , A n .

[0068] Gravitational balance is a process of energy conversion. According to the principle of energy conservation, the sum of the elastic potential energy of the spring 25 and the gravitational potential energy of the object being balanced remains unchanged, that is,

[0069]

[0070] Among them, G represents the gravity of the object to be balanced, L represents the distance between the center of the object to be balanced and the rotation center, K represents the stiffness of the spring 25, α represents the rotation angle of the object to be balanced, 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 the initial elongation Δx, so Δx=l0 is defined. After the action of the X-shaped balancing unit 30, the elongation of the spring 25 is and

[0073]

[0074] 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 50 segments l i At any rotation angle α, it is proportional to l0, and the 50 sections of the rope are parallel to each other, that is, A0B0∥A1B1∥...∥A n-1 B n-1 ∥A n B n ,definition

[0075]

[0076] Obviously, i Each rope has 50 sections. i The ratio to l0,

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

[0078] 3) Select the scaling factor t;

[0079] 4) Under the premise of satisfying formula (3), determine y i ;

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

[0081] The specific winding method of the rope 50 is as follows: starting from the left rotating pulley 37, the rope 50 passes 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 connects to the baffle 23. When there are four pulleys, the winding of the rope 50 is a special case of the "bow" shape. Since the fixed pulleys and the rotating pulleys are symmetrically arranged, the rope 50 section between the left rotating pulley 37 and the left fixed pulley 44 is parallel to the rope 50 section between the right rotating pulley 38 and the right fixed pulley 45, satisfying the requirements of formula (4).

[0082] Proof of X-Balance Unit 30's ability to improve gravity balance:

[0083] The stiffness of spring 25 is K=GL / ab, where G represents the gravity of the object being balanced, L represents the distance from the center of gravity of the object being balanced to the center of the first rotation sub, and a and b represent the distances from the outermost fixed pulley and the outermost rotating pulley to the center of the first rotation sub, respectively. Transform this formula, that is, Where t is the scaling factor.

[0084] It can be seen that when the X-shaped balancing unit 30 is used, the deformation of the spring 25 becomes Then the stiffness of spring 25 will become If the stiffness of the spring 25 is not changed, then according to the expression of the stiffness of the spring 25, the weight of the object to be balanced will become tG. The above conclusions show that the X-shaped balancing unit 30 improves the ability of gravity balancing.

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

[0086] (1) According to different types of exoskeleton devices, the knob 39 is rotated to control the fixed pulley on the dual-rotation screw 40 to move in the opposite direction or in the opposite direction and adjust it to a suitable position;

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

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

[0089] Embodiment 2

[0090] Figure 7 1 is a simplified structural diagram of an X-shaped balancing unit 30 with multiple pulleys in the first embodiment of the present invention.

[0091] like Figure 7 As shown, when the number of pulleys is greater than four, when adjusting the pulley position, in order to satisfy equation (4), it is necessary to consider the moving speed of the pulley on the same side. When no adjustment is made, then,

[0092]

[0093] After the pulley position is adjusted, the following conclusions are theoretically established:

[0094]

[0095] Combining formulas (5) and (6), we can get that the moving distance of the pulley satisfies,

[0096]

[0097] Formula (7) shows that the moving distances between the pulleys on the same side of the adjustable module 32 are proportional.

[0098] The rope 50 is wound around the pulley in a bow shape, and the rope 50 forms rope sections 50 with different lengths between the fixed pulley and the rotating pulley. i, 50 ropes of different lengths are parallel to each other, and the sum of the lengths of the 50 ropes is Wherein, n represents the number of the rope 50 segments, and Δx represents the length of the rope 50 segments between the fixed pulley and the rotating pulley when n=2.

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

[0100] like Figure 8 As shown, the adjustable module 32 includes an optical axis 41, a dual-rotation screw 40 and a knob 39. The dual-rotation screw 40 is composed of screws with different leads, including at least a first lead 48 and a second lead 49. The proportional relationship between the leads satisfies formula (7). The knob 39 is fixedly connected to the dual-rotation screw 40.

[0101] For the convenience of expression, in this embodiment, the same symbols are given to the same structures as those in the first embodiment, and the same descriptions are omitted.

[0102] Embodiment 3

[0103] The active rod body 34 is also provided with an adjustable module 32, so as to control the position of the rotating pulley on the active rod body 34, so that the rotating pulley moves towards or in opposite directions.

[0104] For the convenience of expression, in this embodiment, the same symbols are given to the same structures as those in the first embodiment, and the same descriptions are omitted.

[0105] Functions and Effects of the Embodiments

[0106] According to the exoskeleton gravity balancing mechanism involved in the present invention, compared with the traditional rope-pulley unit, the present invention can improve the balancing ability of the mechanism without changing the movement characteristics of the balanced object, that is, expand the application range of the mechanism.

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

[0108] In a conventional exoskeleton device, the balance unit is generally integrated with the exoskeleton body, which is not easy to maintain. The present invention 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 present invention is used to change the direction of the rope so that the spring connected thereto can be installed in a suitable position. The position of the auxiliary pulley can be flexibly adjusted to make the overall structure more compact, thereby improving the balancing performance of the exoskeleton gravity balancing mechanism.

[0110] The present invention adjusts the pulley position through an adjustable module to change the balanced gravity, and combines the unique pulley arrangement and rope winding method of the X-shaped balancing unit to improve the performance of the exoskeleton gravity balancing module while expanding the scope of application.

[0111] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached 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 periphery 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 installed on the base through 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. The output shaft passes through the base and the X-shaped balancing unit and is connected to the exoskeleton device. The output shaft rotates under the drive of the exoskeleton device. The pulleys are respectively arranged at both ends of the active rod body. The two ends of the active rod body can rotate along the arc-shaped notch. The adjustable module is fixed on the base. The pulleys are respectively arranged at both ends of the adjustable module. The adjustable module can control the position of the pulley. A front cover is arranged above the X-shaped balancing unit and is fixedly connected to the base, and a hole for passing the output shaft is opened in the middle of the front cover; A rope, one end of which is fixed to the pulley of the X-shaped balancing unit and passes around the other pulleys, and the other end of which 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, The base is provided with a hollow rectangular stopper with one side open, the stopper is provided in the middle of the stopper, and both ends of the stopper are slidably connected with the stopper, so that the stopper can slide inside the stopper.

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

4. The exoskeleton gravity balancing mechanism according to claim 3, characterized in that: in, The fixed pulley is denoted by the letter A i Indicates that the rotating pulley is B i Indicates that the total number of pulleys is 2n, and the first pulley is defined as A0 and the end pulley is A n ,and The rope is wound in a "bow" shape, starting from pulley A0, 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 energy conservation, the sum of the elastic potential energy of the spring and the gravitational potential energy of the object being balanced remains unchanged, that is, Among them, 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-type balancing unit is to amplify the initial elongation Δx, so Δx=l0 is defined. After the action of the X-type 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, and is used to drive 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 the "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 equation (4), the moving speed of the pulley on the same side needs to be considered. When no adjustment is performed, 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) indicates 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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