A waist exoskeleton robot based on series elastic actuator

Abstract

The present invention provides a waist exoskeleton robot based on a series elastic driver, which relates to the technical field of medical robots: comprising: two binding parts, namely a lower binding part and an upper binding part arranged above the lower binding part; and four series elastic drivers, the four series elastic drivers are arranged symmetrically in pairs, and the upper end of the upper connecting rod of each series elastic driver can be rotatably connected to the waist guard plate of the upper binding part, and the lower end of the lower connecting rod can be rotatably connected to the waist guard plate of the lower binding part. Beneficial effects of the present invention: the four series elastic drivers generate an upward driving force, which jointly drive the upper binding part and the lower binding part to generate an upward traction force, thereby generating an upward traction effect on the lumbar spine, ensuring the stretching of the lumbar spine in standing and sitting states, simulating waist muscle movement to achieve traction rehabilitation or rehabilitation exercise prescription training of the human waist, and the four series elastic drivers form a parallel mechanism, which improves the portability of the parallel waist exoskeleton.

Description

Technical Field

[0001] The invention relates to the technical field of medical robots, and in particular to a waist exoskeleton robot based on a series elastic driver. Background Art

[0002] The waist exoskeleton robot is a new type of rehabilitation equipment that can make rehabilitation training standardized, long-lasting and quantitative. It can provide effective motor function assistance for patients with low back pain, promote the remodeling of damaged nerve and muscle functions in patients, and can be used for low back pain prevention and rehabilitation assistance. The current waist exoskeleton robots are mainly divided into serial and parallel mechanisms. Among them, the serial waist exoskeleton mechanism is mostly used in scenes such as carrying assistance to improve the user's load capacity, and due to limitations such as insufficient degrees of freedom of the serial mechanism, it is difficult to use for rehabilitation exercise training for patients with low back pain. Parallel waist exoskeleton mechanisms are mostly large in size and lack portability, and are mainly limited to use in fixed places, or are directly driven by rigid drivers such as electric push rods and joint motors, which do not have passive flexibility, are often insufficient in comfort, and are prone to secondary injuries to users. Summary of the invention

[0003] In view of this, in order to solve the above-mentioned problems existing in the waist exoskeleton robot, an embodiment of the present invention provides a waist exoskeleton robot based on a series elastic drive.

[0004] An embodiment of the present invention provides a waist exoskeleton robot based on a series elastic actuator, comprising:

[0005] Two binding pieces, namely a lower binding piece and an upper binding piece arranged above the lower binding piece, each of the binding pieces comprises a flexible binding belt and two waist guard plates arranged on the outer surface of the flexible binding belt, and the two waist guard plates are arranged symmetrically on the left and right;

[0006] And four series elastic drivers, each of which includes a shell and a driving component arranged in the shell, the driving component includes a motor, a screw mechanism, a lower connecting rod, a first film pressure sensor, an upper connecting rod, a sensing slider and a second film pressure sensor, the motor is connected to the screw mechanism, the screw mechanism is connected to the lower connecting rod to drive the lower connecting rod to move vertically, the first film pressure sensor is arranged on one side of the lower connecting rod, a first contact head is arranged on the side of the nut slider, the first contact head is connected to the first film pressure sensor, the upper connecting rod is vertically arranged, the sensing slider is fixedly arranged on the upper connecting rod, the sensing slider can be vertically slidably installed in the shell, elastic parts are arranged on the upper and lower sides of the sensing slider on the upper connecting rod, the second film pressure sensor is arranged on one side of the upper connecting rod, the sensing slider is provided with a second contact head, and the second contact head is connected to the second film pressure sensor;

[0007] Among them, the four series elastic drivers are symmetrically arranged in pairs, and the upper end of the upper connecting rod of each series elastic driver can be rotatably connected to the waist guard plate of the upper binding piece, and the lower end of the lower connecting rod can be rotatably connected to the waist guard plate of the lower binding piece.

[0008] Furthermore, the screw mechanism includes a screw rod and a nut slider, the nut slider is sleeved on the screw rod, the lower connecting rod is an internal threaded tube, one end of the screw rod can be rotatably set and connected to the motor, and the other end is inserted into the upper end of the lower connecting rod, and the upper end of the lower connecting rod is fixedly connected to the nut slider.

[0009] Furthermore, the motor is connected to the screw rod via a gear set.

[0010] Furthermore, a guide cylinder is sleeved on the upper connecting rod, and the guide cylinder is fixed in the outer shell. The upper connecting rod can slide through the guide cylinder, and one elastic member is arranged between the guide cylinder and the sensing slider, and the other elastic member is arranged on the side of the sensing slider away from the guide cylinder.

[0011] Furthermore, the elastic member is a spring, and the two elastic members are sleeved on the upper connecting rod.

[0012] Furthermore, an upper joint ball bearing is provided at the upper end of the upper connecting rod and is connected to the waist guard plate of the upper binding piece through the upper joint ball bearing, and a lower joint ball bearing is provided at the lower end of the lower connecting rod and is connected to the waist guard plate of the lower binding piece through the lower joint ball bearing.

[0013] Furthermore, the upper connecting rod and the lower connecting rod are both arranged vertically, and the first film pressure sensor and the second film pressure sensor are arranged between the upper connecting rod and the lower connecting rod.

[0014] Furthermore, the binding component also includes four connecting plates, the waist guard plate is arc-shaped, and every two connecting plates are respectively arranged on the outer side surfaces of the two ends of a waist guard plate, and the four connecting plates of the upper binding component and the four connecting plates of the lower binding component are arranged one by one up and down, and the upper end of the upper connecting rod and the lower end of the lower connecting rod of each series elastic driver can be rotatably connected to the two connecting plates correspondingly arranged up and down.

[0015] Furthermore, it also includes a control system, which is connected to the motor, the first film pressure sensor and the second film pressure sensor of each of the series elastic drivers, and is used to control the motor to drive the lower connecting rod to extend and retract, and calculate the length of the series elastic driver in real time through the first film pressure sensor and the second film pressure sensor, adjust the distance between the upper binding and the lower binding, and realize waist exercise training.

[0016] Further, the control system adjusts the distance between the upper binding member and the lower binding member according to the following method:

[0017] The platform formed by the rotatable connection points of the two waist guard plates and the four lower connecting rods on the lower binding member is used as a fixed platform, and the rectangular length of the fixed platform is 2a and the width is 2b;

[0018] The platform formed by the rotatable connection points of the two waist guard plates and the four upper connecting rods on the upper binding member is used as a motion platform, and the motion platform rectangle has a length of 2e and a width of 2f;

[0019] Establish fixed coordinate systems on the fixed platform and the moving platform respectively o-xyz and motion coordinate system o 1 -x 1 y 1 z 1, where the coordinate origin o , o 1 are located at the geometric center of the fixed platform and the moving platform respectively, x , x 1 Coordinate axis parallel to A 1 A 4; y , y 1 Coordinate axis parallel to A 1 A 2; z , z 1 The coordinate axis is perpendicular to the fixed platform and the moving platform;

[0020] The moving platform has three rotational motions and along the fixed platform. Z The movement in the axis direction, the motion coordinate system o 1 -x 1 y 1 z 1 Relative fixed coordinate system o-xyz The displacement and rotation angle are expressed as (0, 0, z; , , ); each rotation point of its motion platform B i In the motion coordinate system o 1 -x 1 y 1 z 1 and fixed coordinate system o-xyz Respectively expressed as ( B ix1 , B iy1 , B iz1 )and( Bix , B iy , B iz ); Fixed platform rotation points A i In a fixed coordinate system o-xyz It is expressed as ( A ix , A iy , A iz ), each rotation point of the motion platform B i In a fixed coordinate system o-xyz The coordinates in are defined as follows:

[0021]

[0022] in:

[0023]

[0024] The length of the elastic actuator in series between the moving platform and the fixed platform is defined as follows:

[0025]

[0026] In the formula, For the The length of the root drive branch, ;

[0027] Fix the platform rotation point , the motion platform rotation point In a fixed coordinate system Substituting the coordinate values ​​of into the calculation, the specific expression of the inverse kinematics equation of each series elastic actuator can be obtained as follows:

[0028]

[0029] According to the establishment of the inverse kinematics equations of the above-mentioned series elastic actuators, the driving length of each series elastic actuator can be inversely calculated according to the posture information of the moving platform relative to the fixed platform.

[0030] The technical solution provided by the embodiment of the present invention has the following beneficial effects:

[0031] 1. A waist exoskeleton robot based on a series elastic driver of the present invention has four series elastic drivers between an upper binding part and a lower binding part, and the upper binding part and the lower binding part are respectively bound to the user's waist. The non-vertical forces of the four series elastic drivers will cancel each other out, leaving only the vertical upward force, so that the four series elastic drivers generate an upward driving force, and jointly drive the upper binding part and the lower binding part to generate an upward traction force, thereby generating an upward traction effect on the lumbar spine, ensuring the stretching of the lumbar spine in standing and sitting states, simulating waist muscle movement to achieve traction rehabilitation or rehabilitation exercise prescription training of the human waist, and the four series elastic drivers form a parallel mechanism, which improves the portability of the parallel waist exoskeleton.

[0032] 2. The waist exoskeleton robot based on a series elastic driver of the present invention can adjust the length and position of the series elastic driver through force control or position control of the series elastic driver to control four series elastic drivers to achieve specific rehabilitation exercise training for the waist, thereby controlling the force and posture of the upper binding parts of the exoskeleton worn on the user's waist, thereby achieving traction rehabilitation or rehabilitation exercise prescription training for the user's waist.

[0033] 3. The waist exoskeleton robot based on a series elastic driver of the present invention is driven by a series elastic driver. Compared with rigid drivers such as electric push rods, the use of a series elastic driver greatly improves the passive compliance of the device, avoids the problem of poor compliance of rigid drivers, and further improves the wearing comfort and safety of the device.

[0034] 4. The present invention provides a waist exoskeleton robot based on a series elastic drive. The series elastic drive realizes simple external driving force and displacement measurement through two thin film pressure sensors, which simplifies the measurement of driving force on each series elastic drive, avoids the use of expensive tension and pressure sensors, and simplifies the structure of the series elastic drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of a waist exoskeleton robot based on a series elastic actuator of the present invention;

[0036] Figure 2 It is an exploded view of a waist exoskeleton robot based on a series elastic actuator of the present invention;

[0037] Figure 3 is an exploded diagram of the series elastic actuator;

[0038] Figure 4 is a cross-sectional view of a series elastic actuator;

[0039] Figure 5 It is an exploded view of the drive assembly;

[0040] Figure 6 It is a motion mapping principle diagram of a waist exoskeleton robot based on a series elastic actuator of the present invention;

[0041] Figure 7 It is a schematic diagram of the movement principle of a waist exoskeleton robot based on a series elastic drive of the present invention.

[0042] In the figure: 1. upper binding member; 101. flexible binding belt; 102. waist guard plate; 103. connecting plate; 2. series elastic driver; 201. shell; 202. connecting frame; 203. bolt; 204. motor; 205. screw rod; 206. nut slider; 207. first contact head; 208. lower connecting rod; 209. first film pressure sensor; 210. lower joint ball bearing; 211. driving gear; 212. driven gear; 213. deep groove ball bearing; 214. upper connecting rod; 215. induction slider; 216. elastic member; 217. second contact head; 218. second film pressure sensor; 219. guide cylinder; 220. upper joint ball bearing; 3. lower binding member. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in conjunction with the accompanying drawings. The following is a preferred embodiment of the present invention, which is intended to provide a basic understanding of the present invention, but is not intended to confirm the key or decisive elements of the present invention or to limit the scope of protection.

[0044] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0045] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0046] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in the subsequent drawings. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0047] It should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" 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 or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Please refer to Figure 1 and 2 An embodiment of the present invention provides a waist exoskeleton robot based on a series elastic actuator, comprising two binding members and four series elastic actuators 2.

[0049] The two binding parts are a lower binding part 3 and an upper binding part 1 arranged above the lower binding part 3. The lower binding part 3 is used to be bound to the user's pelvic plane, and the upper binding part 1 is bound to the lumbar plane above the user's waist pelvis.

[0050] Each of the binding parts includes a flexible binding belt 101 and two waist guard plates 102 arranged on the outer surface of the flexible binding belt 101, and the two waist guard plates 102 are arranged symmetrically. The flexible binding belt 101 is made of flexible material, generally arranged in a rectangular strip shape, and a strong felt is arranged at the end. After the flexible binding belt 101 fits around the user's waist, it can be bound by the strong felt.

[0051] The waist guard plate 102 is generally arc-shaped so as to fit the waist of the user well. The waist guard plate 102 fits the outer surface of the flexible strap 101 and is fastened with screws.

[0052] The four serial elastic drivers 2 are arranged between the upper binding member 1 and the lower binding member 3, and each serial elastic driver 2 is connected to the upper binding member 1 at the top and the lower binding member 3 at the bottom, forming a parallel mechanism. The serial elastic drivers 2 are used to generate a driving force to drive the user's waist exoskeleton to move and achieve a specific stretching force or a preset trajectory.

[0053] like Figure 3 , 4 As shown in Figure 5, each of the series elastic drivers 2 specifically includes a shell and a driving component arranged in the shell, and the driving component includes a motor 204, a screw mechanism, a lower connecting rod 208, a first film pressure sensor 209, an upper connecting rod 214, a sensing slider 215 and a second film pressure sensor 218.

[0054] The motor 204 is connected to the screw mechanism, and the screw mechanism is connected to the lower connecting rod 208 to drive the lower connecting rod 208 to move vertically. Specifically, in this embodiment, the housing includes two shells 201 and a connecting frame 202, the two shells 201 are fastened and connected by bolts 203, and the connecting frame 202 is fixedly installed between the two shells 201. The driving assembly is installed on the connecting frame 202.

[0055] The screw mechanism is a T-type screw mechanism, including a screw rod 205 and a nut slider 206, wherein the nut slider 206 is sleeved on the screw rod 205 and is threadedly connected to the screw rod 205. The lower connecting rod 208 is an internal threaded tube, and one end of the screw rod 205 is rotatably arranged and connected to the motor 204. Here, the lower end of the screw rod 205 is rotatably installed in the housing through a deep groove ball bearing 213, and the other end is inserted into the upper end of the lower connecting rod 208 and is threadedly connected to the inner hole of the lower connecting rod 208, and the upper end of the lower connecting rod 208 is fixedly connected to the nut slider 206. In this way, the motor 204 drives the screw rod 205 to rotate, drives the nut slider 206 to move along the vertical direction, and thus drives the lower connecting rod 208 to move vertically.

[0056] In some embodiments, the motor 204 is connected to the lead screw 205 via a gear set. Specifically, the motor 204 is a micro DC brushed motor 204, which is fixed in the housing and located on one side of the lead screw 205. The gear set includes a meshing driving gear 211 and a driven gear 212, the output end of the motor 204 is connected to the driving gear 211, and the driven gear 212 is sleeved on the lower end of the lead screw 205. The motor 204 drives the driving gear 211 to rotate, thereby driving the driven gear 212 to rotate, thereby driving the lead screw 205 to rotate.

[0057] The first film pressure sensor 209 is arranged on one side of the lower connecting rod 208, and a first contact head 207 is provided on the side of the nut slider 206. The first film pressure sensor 209 is fixedly installed in the shell, and the first contact head 207 is connected to the first film pressure sensor 209 to realize the contact installation of the first contact head 207.

[0058] The upper connecting rod 214 is vertically arranged, and the sensing slider 215 is fixedly arranged on the upper connecting rod 214. The sensing slider 215 can be vertically slidably installed in the shell. The upper connecting rod 214 is provided with elastic parts 216 on the upper and lower sides of the sensing slider 215. The second film pressure sensor 218 is arranged on one side of the upper connecting rod 214. The sensing slider 215 is provided with a second contact head 217, and the second contact head 217 is connected to the second film pressure sensor 218.

[0059] The two elastic members 216 are both arranged in the movement direction of the upper connecting rod 214, and the movement of the upper connecting rod 214 will drive the two elastic members 216 to undergo elastic deformation. Specifically, the upper connecting rod 214 is sleeved with a guide cylinder 219, the guide cylinder 219 is fixed in the housing, the upper connecting rod 214 can slide through the guide cylinder 219, one elastic member 216 is arranged between the guide cylinder 219 and the sensing slider 215, and the other elastic member 216 is arranged on the side of the sensing slider 215 away from the guide cylinder 219. The elastic member 216 can be a spring, and the two elastic members 216 are sleeved on the upper connecting rod 214.

[0060] When the upper connecting rod 214 moves, it will drive the sensing slider 215 to slide vertically in the housing, so that the second contact head 217 generates pressure in the second film pressure sensor 218, thereby measuring the compression of the two elastic members 216 in real time, and calculating the tension or pressure generated by the series elastic driver 2 through Hooke's law, avoiding the use of expensive tension and pressure and complex structural design.

[0061] In some embodiments, the upper connecting rod 214 and the lower connecting rod 208 are both arranged vertically, and the first film pressure sensor 209 and the second film pressure sensor 218 are arranged between the upper connecting rod 214 and the lower connecting rod 208, which can make the structure of the series elastic driver 2 more compact.

[0062] The four serial elastic drivers 2 are symmetrically arranged in pairs, and the upper end of the upper connecting rod 214 of each serial elastic driver 2 can be rotatably connected to the waist guard plate 102 of the upper binding member 1, and the lower end of the lower connecting rod 208 can be rotatably connected to the waist guard plate 102 of the lower binding member 3.

[0063] Specifically, the upper end of the upper connecting rod 214 extends out of the housing and is provided with an upper joint ball bearing 220, and the upper end of the upper connecting rod 214 is hingedly connected to the waist guard plate 102 of the upper binding member 1 through the upper joint ball bearing 220, and the lower end of the lower connecting rod 208 extends out of the housing and is provided with a lower joint ball bearing 210, and the lower end of the lower connecting rod 208 is hingedly connected to the waist guard plate 102 of the lower binding member 3 through the lower joint ball bearing 210. The upper joint ball bearing 220 and the lower joint ball bearing 210 are both connected to the waist guard plate 102 through screws.

[0064] In some embodiments, the binding component also includes four connecting plates 103, and the binding component is connected to the series elastic driver 2 through the connecting plates 103. Every two connecting plates 103 are respectively arranged on the outer side surfaces of the two ends of a waist guard plate 102, and the four connecting plates 103 of the upper binding component 1 and the four connecting plates 103 of the lower binding component 3 are arranged one by one up and down. The upper end of the upper connecting rod 214 and the lower end of the lower connecting rod 208 of each of the series elastic drivers 2 can be rotatably connected to the two corresponding connecting plates 103 arranged up and down.

[0065] In each of the series elastic actuators 2, the motor 204 drives the screw rod 205 to rotate, so that the nut slider 206 slides in the vertical direction. The sliding of the nut slider 206 can drive the lower connecting rod 208 to move, and drive the first contact head 207 to move, thereby generating pressure on the first film pressure sensor 209, thereby changing the change in the internal resistance of the first film pressure sensor 209, and the position of the nut slider 206 can be measured. While the lower connecting rod 208 moves, the upper connecting rod 214 is adaptively moved vertically, and the upper end of the upper connecting rod 214 generates tension and thrust on the upper binding member 1, generating driving force for the upper binding member 1, driving the user's waist exoskeleton to move, and achieving a specific tensile force or a preset trajectory. And when the upper connecting rod 214 moves, it drives the sensing slider 215 to move on the second film pressure sensor 218, generating pressure on the second film pressure sensor 218, and the position of the nut slider 206 can be measured. The movement of the upper connecting rod 214 also compresses one of the two elastic members 216 and stretches the other one, and the tension or pressure generated by the series elastic driver 2 can be calculated by Hooke's law, thereby avoiding the use of expensive tension and pressure and complex structural design.

[0066] When the lower binding member 3 is bound to the user's pelvic plane and the upper binding member 1 is bound to the lumbar plane above the user's waist and pelvis, the four series elastic drivers 2 are symmetrically arranged. When the four series elastic drivers 2 all generate the same upward force on the upper binding member 1, the non-vertical forces will offset each other, leaving only the vertical upward force, thereby ensuring the stretching of the lumbar spine in standing and sitting states.

[0067] In addition, if Figure 6 and 7As shown, a waist exoskeleton robot based on a series elastic driver of the present invention also includes a control system, which is connected to the motor 204, the first film pressure sensor 209 and the second film pressure sensor 218 of each of the series elastic drivers 2, and is used to control the motor 204 to drive the lower connecting rod 208 to extend and retract, and calculate the length of the series elastic driver 2 in real time through the first film pressure sensor 209 and the second film pressure sensor 218, adjust the distance between the upper binding member 1 and the lower binding member 3, and realize waist movement training.

[0068] In addition to simple traction rehabilitation of the lumbar spine, the waist exoskeleton robot based on the series elastic drive of the present invention can also achieve specific rehabilitation exercise training tasks according to the prescribed rehabilitation exercise prescription. The control system adjusts the distance between the upper binding member 1 and the lower binding member 3 according to the following method:

[0069] The platform formed by the rotatable connection points of the two waist guard plates 102 and the four lower connecting rods 208 on the lower binding member 3 is used as a fixed platform, and the rectangular length of the fixed platform is 2a and the width is 2b;

[0070] The platform formed by the rotatable connection points of the two waist guard plates 102 and the four upper connecting rods 214 on the upper binding member 1 is used as a motion platform, and the motion platform rectangle has a length of 2e and a width of 2f;

[0071] The motion platform and the fixed platform are mapped to the user's lumbar plane and pelvic plane respectively. A virtual constraint branch chain between the motion platform and the fixed platform l 5 is mapped to the user's lumbar spine. The series elastic actuator 2 is mapped to the user's waist muscles;

[0072] Establish fixed coordinate systems on the fixed platform and the moving platform respectively o-xyz and motion coordinate system o 1 -x 1 y 1 z 1, where the coordinate origin o , o 1 are located at the geometric center of the fixed platform and the moving platform respectively, x , x 1 Coordinate axis parallel to A 1 A 4; y , y 1 Coordinate axis parallel to A 1 A 2; z , z 1 The coordinate axis is perpendicular to the fixed platform and the moving platform;

[0073] The moving platform has three rotational motions and along the fixed platform. Z The movement in the axis direction, the motion coordinate system o 1 -x 1 y 1 z 1 Relative fixed coordinate system o-xyz The displacement and rotation angle are expressed as (0, 0, z; , , ); each rotation point of its motion platform B i In the motion coordinate system o 1 -x 1 y 1 z 1 and fixed coordinate system o-xyz Respectively expressed as ( B ix1 , B iy1 , B iz1 )and( B ix , B iy , B iz ); Fixed platform rotation points A i In a fixed coordinate system o-xyz It is expressed as ( A ix , A iy , A iz ), each rotation point of the motion platform B i In a fixed coordinate system o-xyz The coordinates in are defined as follows:

[0074]

[0075] in:

[0076]

[0077] T is the homogeneous transformation matrix of the parallel mechanism composed of four series elastic actuators 2, which represents the mapping relationship between the parallel mechanism motion coordinate system and the fixed coordinate system, and can be regarded as a simple matrix form to represent the rotation and translation of the general transformation. , , the other simplified expressions are the same; in the lumbar rehabilitation exoskeleton mechanism , , They correspond to the angle ranges of waist flexion and extension, left and right lateral flexion, and left and right rotation of the user. The distance moved along the direction of the human body corresponding to the user completing the above-mentioned movement;

[0078] The length of the elastic actuator in series between the moving platform and the fixed platform is defined as follows:

[0079]

[0080] In the formula, For the The length of the root drive branch, ;

[0081] Fix the platform rotation point , the motion platform rotation point In a fixed coordinate system Substituting the coordinate values ​​of into the calculation, the specific expression of the inverse kinematics equation of each series elastic actuator 2 can be obtained as follows:

[0082]

[0083] According to the establishment of the inverse kinematics equations of the above-mentioned series elastic actuators, the driving length of each series elastic actuator 2 can be inversely calculated according to the posture information of the moving platform relative to the fixed platform.

[0084] Furthermore, the control system controls the motor 204 of each of the series elastic actuators 2 to drive the lower connecting rod 208 to contract or extend, and the first film pressure sensor 209 and the second film pressure sensor 218 calculate the overall length information of the series elastic actuator 2 in real time for feedback, thereby realizing the length of the series elastic actuator 2 (i.e. l i ) to achieve waist specific posture movement. Specifically, for waist rehabilitation exercise prescription, the length of each series elastic driver 2 is inversely calculated according to the inverse kinematics equation established above, so as to control each series elastic driver 2 to achieve waist specific rehabilitation exercise training action, so as to promote the remodeling of the damaged nerve and muscle function of the user.

[0085] In this article, the directional words such as front, back, top, and bottom involved are defined by the positions of the parts in the drawings and the positions of the parts relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that they are relative concepts and can change accordingly according to different ways of use and placement, and the use of the directional words should not limit the scope of protection claimed in this application.

[0086] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A waist exoskeleton robot based on a series elastic actuator, characterized in that: include: Two binding pieces, namely a lower binding piece and an upper binding piece arranged above the lower binding piece, each of the binding pieces comprises a flexible binding belt and two waist guard plates arranged on the outer surface of the flexible binding belt, and the two waist guard plates are arranged symmetrically on the left and right; and four series elastic drivers, each of which comprises a housing and a driving assembly arranged in the housing, the driving assembly comprising a motor, a screw mechanism, a lower connecting rod, a first film pressure sensor, an upper connecting rod, a sensing slider and a second film pressure sensor, the motor is connected to the screw mechanism, the screw mechanism is connected to the lower connecting rod to drive the lower connecting rod to move vertically, the first film pressure sensor is arranged on one side of the lower connecting rod, the screw mechanism comprises a screw and a nut slider, the nut slider is sleeved on the screw, a first contact head is arranged on the side of the nut slider, the first contact head is connected to the first film pressure sensor, the upper connecting rod is vertically arranged, the sensing slider is fixedly arranged on the upper connecting rod, the sensing slider can be vertically slidably installed in the housing, elastic members are arranged on the upper and lower sides of the sensing slider on the upper connecting rod, the second film pressure sensor is arranged on one side of the upper connecting rod, the sensing slider is provided with a second contact head, and the second contact head is connected to the second film pressure sensor; The four series elastic drivers are symmetrically arranged in pairs, and the upper end of the upper connecting rod of each series elastic driver can be rotatably connected to the waist guard plate of the upper binding member, and the lower end of the lower connecting rod can be rotatably connected to the waist guard plate of the lower binding member; The apparatus further comprises a control system, which is connected to the motors, the first film pressure sensor and the second film pressure sensor of each of the series elastic actuators, and is used to control the motors to drive the lower connecting rod to extend and retract, and calculate the length of the series elastic actuator in real time through the first film pressure sensor and the second film pressure sensor, and adjust the distance between the upper binding member and the lower binding member; the control system adjusts the distance between the upper binding member and the lower binding member according to the following method: The platform formed by the rotatable connection points of the two waist guard plates and the four lower connecting rods on the lower binding member is used as a fixed platform, and the rectangular length of the fixed platform is 2a and the width is 2b; The platform formed by the rotatable connection points of the two waist guard plates and the four upper connecting rods on the upper binding member is used as a motion platform, and the motion platform rectangle has a length of 2e and a width of 2f; Establish fixed coordinate systems on the fixed platform and the moving platform respectively o-xyz and motion coordinate system o 1 -x 1 y 1 z 1, where the coordinate origin o , o 1 are located at the geometric center of the fixed platform and the moving platform respectively, x , x 1 Coordinate axis parallel to A 1 A 4; y , y 1 Coordinate axis parallel to A 1 A 2; z , z 1 The coordinate axis is perpendicular to the fixed platform and the moving platform; The moving platform has three rotational motions and along the fixed platform. Z The movement in the axis direction, the motion coordinate system o 1 - x 1 y 1 z 1 Relative fixed coordinate system o-xyz The displacement and rotation angle are expressed as (0, 0, z; , , ); each rotation point of its motion platform B i In the motion coordinate system o 1 -x 1 y 1 z 1 and fixed coordinate system o-xyz Respectively expressed as ( B ix1 , B iy1 , B iz1 )and( B ix , B iy , B iz ); Fixed platform rotation points A i In a fixed coordinate system o-xyz In the expression ( A ix , A iy , A iz ), each rotation point of the motion platform B i In a fixed coordinate system o-xyz The coordinates in are defined as follows: in: The length of the elastic actuator in series between the moving platform and the fixed platform is defined as follows: In the formula, For the The length of the root drive branch, ; Fix the platform rotation point , the motion platform rotation point In a fixed coordinate system Substituting the coordinate values ​​of into the calculation, the specific expression of the inverse kinematics equation of each series elastic actuator can be obtained as follows: 。 2. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 1, characterized in that: The lower connecting rod is an internal threaded tube, one end of the screw rod is rotatably arranged and connected to the motor, and the other end is inserted into the upper end of the lower connecting rod, and the upper end of the lower connecting rod is fixedly connected to the nut slider.

3. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 2, characterized in that: The motor is connected to the lead screw via a gear set.

4. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 1, characterized in that: The upper connecting rod is sleeved with a guide cylinder, the guide cylinder is fixed in the shell, the upper connecting rod can slide through the guide cylinder, one elastic member is arranged between the guide cylinder and the sensing slider, and the other elastic member is arranged on the side of the sensing slider away from the guide cylinder.

5. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 4, characterized in that: The elastic member is a spring, and the two elastic members are sleeved on the upper connecting rod.

6. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 1, characterized in that: An upper joint ball bearing is provided at the upper end of the upper connecting rod and is connected to the waist guard plate of the upper binding piece through the upper joint ball bearing. A lower joint ball bearing is provided at the lower end of the lower connecting rod and is connected to the waist guard plate of the lower binding piece through the lower joint ball bearing.

7. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 1, characterized in that: The upper connecting rod and the lower connecting rod are both arranged vertically, and the first film pressure sensor and the second film pressure sensor are arranged between the upper connecting rod and the lower connecting rod.

8. A waist exoskeleton robot based on a series elastic actuator as claimed in claim 1, characterized in that: The binding component also includes four connecting plates, the waist guard plate is arc-shaped, and every two connecting plates are respectively arranged on the outer side surfaces of the two ends of a waist guard plate, and the four connecting plates of the upper binding component and the four connecting plates of the lower binding component are arranged one by one up and down, and the upper end of the upper connecting rod and the lower end of the lower connecting rod of each series elastic driver can be rotatably connected to the two corresponding connecting plates arranged up and down.

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