97 results about "Variable stiffness" patented technology

The invention discloses a flexible manipulator with variable clamping force and constant-force rubbing and a using method thereof, and belongs to the technical field of micromanipulators, the flexible manipulator comprises a first driving mechanism, a second driving mechanism, a variable-rigidity clamping mechanism and a constant-force rubbing mechanism, the variable-rigidity clamping mechanism is formed by connecting a guide beam assembly, a variable-rigidity beam assembly and a decoupling beam assembly in series, and the constant-force rubbing mechanism is connected with the first driving mechanism. A first clamping end is arranged at the tail end, the rigidity of the constant force rubbing mechanism can be adjusted through embedded shape memory alloy, the constant force rubbing mechanism is composed of a positive rigidity structure and a negative rigidity structure, a second clamping end opposite to the first clamping end is arranged at the tail end, and the two mechanisms are connected through the decoupling beam assembly to achieve structural decoupling. The problems that an existing flexible manipulator is non-adjustable in clamping rigidity, slow in constant force response and mutual in function interference are solved, and self-adaptive grabbing and stable rubbing of micro-scale objects are achieved.

The present application is a variable stiffness push knife for bipolar forceps in electrosurgery, which is used in the structure of the forceps head, the main body of which is a blade, the blade is divided into several different areas according to its running direction, and the division standard of the areas is that the hardness between adjacent areas is different. The beneficial effects of the present application are: 1. By dividing the blade into areas and adjusting the divided areas, the hardness of different areas is different, the smoothness of the variable stiffness blade in the operation of the curved (or S-shaped) sliding groove is improved, and the closing force required for the push blade to cut the tissue is reduced; 2. The main way to improve the blade is to reduce the material of the blade, so as to save materials, and the overall weight of the blade is reduced.

The present invention discloses a concentric circle-based six-degree-of-freedom adjustable dynamic variable stiffness device, comprising an upper platform, an upper mounting angle seat, an adjustable dynamic variable stiffness mechanism, a lower mounting angle seat and a lower platform. The upper end of the adjustable dynamic variable stiffness mechanism is connected to the upper platform via the upper mounting angle seat, and the lower end of the adjustable dynamic variable stiffness mechanism is connected to the lower platform via the lower mounting angle seat. The device is based on a multi-degree-of-freedom parallel configuration and is composed of six identical adjustable dynamic variable stiffness mechanisms. The adjustable dynamic variable stiffness mechanism can be adjusted to two states: adjustable dynamic low stiffness and adjustable dynamic high stiffness, thereby forming an adjustable dynamic variable stiffness mechanism.

The utility model discloses a variable stiffness mechanism, a frame structure and a simulation test device. The variable stiffness mechanism comprises a frame body (110); the material layers (120) are connected in the frame body (110) and are sequentially stacked in the longitudinal direction (Y); and the connecting rod (130) sequentially penetrates through the frame body (110) and the material layer (120) and is configured to be detachably connected with the frame body (110) and the material layer (120). The frame body and the material layers are connected together through the connecting rods to form a structural part with certain rigidity, different rigidity changes of the structure are achieved by selecting different material layers and the connecting rods, therefore, the deformation mode and the damage mode of the frame structure are adjusted, the test requirement is met, and the structure is reliable and high in flexibility.

The application discloses a spatial spiral compliance mechanism with a variable stiffness characteristic, comprising a variable stiffness component, a bending component and a fixed base, wherein the variable stiffness component comprises a rigid element, two first leaf-shaped flexible hinges and a variable stiffness module, the two first leaf-shaped flexible hinges are oppositely arranged, and opposite ends of the two first leaf-shaped flexible hinges are respectively connected with the rigid element and the fixed base; the rigid element, the two first leaf-shaped flexible hinges and the fixed base enclose a containing space, the containing space is provided with the variable stiffness module, the fixed base is provided with a containing groove, the bending component is connected with the inner wall of the containing groove, and opposite ends of the variable stiffness module are respectively connected with the rigid element and the bending component; the rotation angle of the variable stiffness module is controlled by input displacement of a driver, the continuous and accurate adjustment of the lateral stiffness of the rigid element can be realized, the variable stiffness module can be quickly adjusted to a suitable stiffness value according to different working requirements, and the adaptability of the spatial spiral compliance device is greatly improved.

The application discloses a large-angle variable stiffness flexible joint, which is composed of a plurality of flexible joint modules stacked together; the flexible joint module comprises a lower chassis, a spiral winding type driver, an elastic main bone and an upper chassis, one end of the elastic main bone is connected with the upper chassis, and the other end is connected with the lower chassis; N spiral winding type drivers are connected between the upper chassis and the lower chassis, and N is greater than or equal to 3; the lower chassis is provided with a buckle mounting groove; the upper chassis is provided with a buckle; the spiral winding type driver is provided with a metal wire; the metal wire is connected with a control system; the elastic main bone is of a space groove type structure; the space groove type structure is provided with one or more symmetrical notches on the elastic main bone; and the stiffness of the elastic main bone is adjusted by adjusting three parameters of a groove height H, a groove inner diameter D and a groove spacing AH. The application adopts modular design and the elastic main bone is adjustable, and large-angle bending and variable stiffness of the flexible joint are realized.

A variable stiffness mechanism for robotic applications. A robotic arm segment comprising two bodies pivotably coupled together at one end and having a generally elongate form factor. A spring-loaded carriage moves longitudinally along one of the two bodies and is in contact with the other body, such that the effective rotational stiffness of the pin joint is equal to the stiffness of the carriage spring multiplied by the distance between the pin joint and the spring. The distance between the pin joint and the spring can be varied using a motor and belt drive arrangement. A stopper may be coupled to the belt drive to lock the relative motion of the two bodies.

A variable-stiffness mechanism may be based on compliant beams. The variable-stiffness mechanism may be a compact, compliant, variable stiffness mechanism (CCVSM). Several compliant mechanisms for integrating variable-stiffness are described. The variable-stiffness mechanisms may be based on a compliant beam configuration, a crank-slider configuration, and / or a gear-slider configuration. Relative merits of the variable-stiffness mechanisms are also compared.

The present application relates to the technical field of tire overall preparation, and proposes a variable stiffness tire and a tire overall preparation device, which can adapt to various driving conditions and realize the collaborative optimization of comfort and control performance, and the structure can effectively disperse flexural stress, and is not prone to heat accumulation, bulging and cracking, thereby significantly improving high-speed durability and load capacity, and the matching tire overall preparation device can adapt to the molding process of the tire body, effectively improve tire production efficiency and manufacturing precision, and comprises a tire body and a triangular rubber ring, wherein the tire body comprises a tread, a sidewall and an inner tire ring, the sidewall is divided into a shoulder section, a sidewall middle section and a bead section in the radial direction, the stiffness of the bead section, the shoulder section and the sidewall middle section decreases in turn, the sidewall middle section is a main flexible deformation area, the shoulder section provides lateral restraint, the bead section provides high stiffness support, the tread is fixedly connected with the shoulder section, and the inner tire ring is fixedly connected with the triangular rubber ring.

The utility model discloses a double-ring damper based on variable rigidity, a damping platform system and a cantilever beam structure system, and relates to the field of vibration control and structural dynamics. In order to overcome the defect that in the prior art, effective and continuous rigidity adjustment and vibration suppression cannot be achieved on the premise that external energy and a control system are not needed, according to the technical scheme, an upper annular structure and a lower annular structure are included, and the upper annular structure and the lower annular structure are oppositely arranged and rotationally connected through a connecting component; each semi-elliptical sheet body comprises two cross beams arranged in parallel and two semi-elliptical sheet bodies symmetrically arranged at the two ends of the cross beams; the connecting component is used for realizing rotation of the upper annular structure in a preset angle range relative to the lower annular structure; and the contact rigidity between the upper annular structure and the lower annular structure is changed along with the change of the relative rotation angle. The self-adaptive vibration damper is suitable for working scenes such as a precision platform, a cantilever structure or an electronic equipment mounting base and the like which need to realize passive and self-adaptive vibration damping in a 40-100Hz medium-high frequency vibration environment.

This application provides a grinding and polishing method based on three-dimensional vision guidance and variable stiffness force-resistance control, relating to the field of automatic control. The control equipment acquires the prior estimated stiffness of the workpiece at its current trajectory position as the initial control basis, ensuring uninterrupted grinding. It then dynamically corrects this prior estimated stiffness using real-time observed stiffness measured by a stiffness sensor, obtaining a real-time comprehensive stiffness that more closely approximates the actual contact state. Finally, based on this real-time comprehensive stiffness, the grinding force originally determined by the prior estimated stiffness is adjusted in real time. Thus, even under complex working conditions such as abrupt changes in surface curvature or material variations, the grinding force can still quickly and smoothly adapt to changes in environmental stiffness, significantly improving the real-time performance and stability of constant force grinding and polishing.

The application discloses a variable rigidity control method and a protection system of a crash pad, wherein the inside of the crash pad comprises fixed energy-absorbing units and adjustable energy-absorbing units; the adjustable energy-absorbing units are structural members with anisotropic stress characteristics and can be switched between a first rigidity mode and a second rigidity mode through rotation. When a rear target vehicle meets a collision risk condition, a corresponding collision action area is determined, and the adjustable energy-absorbing units are laterally differentiated and configured based on the distribution of the collision action area in the width direction; meanwhile, different rows of adjustable energy-absorbing units are longitudinally classified and configured based on collision intensity, and position limiting or mechanical locking is performed after entering a preset collision time window. The application can form an asymmetric rigidity distribution under a bias collision working condition and a symmetric rigidity distribution under a non-bias collision working condition, thereby improving energy-absorbing utilization efficiency, reducing eccentric moment and improving overall protection stability.

The invention relates to the field of bridge engineering, in particular to a bridge variable stiffness distribution design method, a variable stiffness supporting system and a bridge structure. Vertical supporting and horizontal force transmission between the main beam and the lower structure are achieved through the variable-rigidity supporting system, in the variable-rigidity supporting system, vertical supporting force is only provided for the main beam through a support, and longitudinal rigidity is provided for the main beam through a variable-rigidity device; through the mode that the functions of providing longitudinal rigidity and vertical bearing capacity are designed separately, the problem that high bearing capacity and small longitudinal rigidity design and manufacturing cannot be achieved at the same time under the condition that a traditional single bridge support needs to meet the bearing capacity requirement and also needs to have the horizontal force transmission function is solved. By means of the variable-rigidity supporting system, according to different pier column heights and different pier column rigidities, reasonable distribution of constraint rigidities of pier columns at different height positions can be achieved by conducting customized design on structural parameters of the corrugated steel pipe, the internal force of a pier is adjusted, and the design economy is improved.

The utility model relates to the technical field of automobile damping, and discloses a unilateral rubber auxiliary spring with variable stiffness characteristic, which comprises an auxiliary spring support, a variable stiffness rubber block vulcanized together is fixedly mounted on the auxiliary spring support, and the variable stiffness rubber block comprises a connecting plate and a collision plate which are positioned at two ends. More than two rubber sub-blocks with the same peripheral size are integrally vulcanized between the connecting plate and the collision plate, the rubber sub-blocks are sequentially arranged according to the hardness, and the hardness of the rubber sub-blocks close to the connecting plate is the highest; rubber with more than two kinds of hardness is used, the top end of the rubber auxiliary spring is soft, and the bottom end of the rubber auxiliary spring is hard, so that variable rigidity is achieved, and switching of first-level rigidity, second-level rigidity or multi-level rigidity is achieved under the medium-load working condition and the heavy-load working condition respectively. More than two kinds of rigidities are realized under the condition that the sizes of the top end and the bottom end of the rubber auxiliary spring are kept consistent; the weight is light, the structure is compact, the comfort in light load can be guaranteed, the supporting effect in heavy load can also be guaranteed, and the service life is greatly prolonged.

The present application provides a mechanically adaptive intervertebral fusion device with variable stiffness, comprising: a deformable structure group and two plates, the deformable structure assembly being disposed between the two plates, the two plates having a critical point spacing value, and when the spacing between the two plates is greater than the critical point spacing value, the multiple structural portions of the deformable structure group are separated, the deformable structure group having a first stiffness, and when the spacing between the two plates is less than or equal to the critical point spacing value, the deformable structure group deforms, some structural portions of the deformable structure group abut against each other, and the mechanically adaptive intervertebral fusion device having a second stiffness, wherein the second stiffness is greater than the first stiffness. The fusion device of the present application can adapt to the internal mechanical environment by changing its own stiffness, exhibiting a lower stiffness when responding to low loads and a higher stiffness when subjected to high loads, thereby improving the mechanical compatibility with adjacent vertebrae, optimizing mechanical load transfer, reducing adjacent vertebral collapse, and promoting vertebral fusion.

The present invention relates to a compact rope-driven wide-range variable stiffness joint based on the lever principle, comprising: a base module; a decoupling mechanism connected to the base of the base module and disposed above the base module; a driving mechanism disposed above a driven wheel of the decoupling mechanism; a variable stiffness mechanism disposed above the driving mechanism; and an output mechanism disposed at the top of the compact rope-driven wide-range variable stiffness joint based on the lever principle and connected to the variable stiffness mechanism. The decoupling mechanism in the compact rope-driven wide-range variable stiffness joint based on the lever principle has the advantages of a compact structure, fast response, no reverse offset, and small error, thereby achieving the technical effect of a stiffness variation range from 0 to infinity.

The application discloses a robot impedance force control method suitable for a variable stiffness environment. First, an impedance filter is determined according to environment parameters, inertia parameters and stiffness parameters of the impedance filter are determined, and a damping parameter is adjusted according to environment stiffness. Then, a reference trajectory of an end effector of a mechanical arm is calculated according to the environment parameters and expected force information, contact force is detected in real time, and a contact force error is calculated, so that the contact force error is converted into a position deviation through a constant impedance filter or a variable impedance filter, the position deviation is superimposed with the reference trajectory to obtain a command position of the end effector of the mechanical arm, and finally, the end effector operates according to the command position to realize accurate force control. The scheme of the application applies different impedance filters according to the known or unknown environment stiffness, can be applied to a work scene with variable environment stiffness, and compared with a traditional impedance force control method, can realize stable operation and accurate force control of the mechanical arm in the variable stiffness environment, and is conveniently applied to various application scenes.

A variable-stiffness joint multi-leg walking platform comprises identical left front, left rear, right rear, and right front leg mechanisms (A, B, C, D), a trunk (E), and push rods (F). Specifically, the platform is a highly maneuverable closed-chain leg-type walking platform with two joint stiffness modes. Each leg mechanism is driven by a motor. A push rod rotating connector (F‑3) in the left push rod mechanism (F) is fixedly connected to a push rod long connector (A‑1‑1) in a variable-stiffness joint (A‑1) via bolts. During operation of the push rods, a speed difference is achieved via two first thigh rods (A‑2‑1) and gears 1 (A‑1‑5), 2 (A‑1‑6), and 3 (A‑1‑7), thereby completing the conversion between joint stiffness and flexibility. Compared to existing walking platforms, the platform's terrain adaptability can be improved by varying joint stiffness. While reconstructing vibration reduction in the pitch state, energy loss caused by inconsistent traction speeds in the front and rear legs can be reduced.

The invention discloses a multi-mode sensing gripping device and method based on a variable rigidity logarithmic spiral configuration, and is characterized in that the device comprises a driving module and a plurality of gripping blocks which are sequentially arranged along a logarithmic spiral, and the adjacent gripping blocks are hinged; wherein each grasping block comprises a skeleton main body outer layer, a variable rigidity middle layer and a buffer inner layer; wherein the skeleton main body outer layer is used for providing device support and appearance deformation; the variable rigidity middle layer is used for realizing local rigidity adjustment; a multi-modal sensor module for collecting multi-modal grasping data of the grasping block is distributed on the grasping block; and the driving module is connected with each grasping block. Through organic combination of a logarithmic spiral configuration and a variable rigidity material, and meanwhile, a flexible touch sensor array is arranged on the inner layer of the grabbing device, so that real-time detection and cooperative adjustment of rigidity, form and force control in the grabbing process are realized.

The present application relates to the field of material mechanical property characterization, in particular to a high-temperature thermal softening variable stiffness and strength metal elastic-plastic parameter global characterization method, comprising: obtaining strain field data and temperature field data of the test piece, and tensile load data; constructing a thermal-mechanical coupling elastic-plastic constitutive model of the metal plate, and establishing a target function of temperature-related parameters to be solved under the constraint of multiple virtual fields based on the virtual work principle; accurately identifying high-temperature thermal softening elastic parameters by using elastic stage data, and then identifying anisotropic strength thermal softening plastic parameters by using composite field data of the whole loading process under variable stiffness; the present application breaks through the condition restriction of constant stiffness when characterizing thermal-mechanical coupling properties of metal materials by using existing test methods, and can realize global accurate characterization of high-temperature thermal softening and anisotropic complex elastic-plastic thermal-mechanical coupling property parameters by only one test, thereby minimizing the number of tests and simplifying the test process.

This invention provides a method for estimating the external force of a variable stiffness joint based on current information. The overall output torque of the joint is set as the sum of the output torques of the position drive module and the stiffness adjustment module, which more closely approximates the actual output torque, thereby improving the accuracy of external force estimation based on current information. Furthermore, all parameters in the dynamic model can be obtained through measurement or identification of dynamic parameters, further reducing the impact of model errors on external force estimation. This invention provides a method for estimating the external force of a variable stiffness joint based on the fusion of current and elastic deformation, improving the resolution of external force estimation under dynamic stiffness and enabling high-precision external force estimation of variable stiffness joints.

A rope-driven test system for variable stiffness manipulator and variable stiffness gripper includes a two-degree-of-freedom passive motion part, a three-degree-of-freedom active motion part, a pure rigid manipulator, a flexible joint, a variable stiffness manipulator and a variable stiffness gripper, and a frame. The two-degree-of-freedom passive motion part allows manual adjustment of the posture, and the three-degree-of-freedom active motion part realizes accurate operation through motor driving. The pure rigid manipulator provides high stiffness operation, and the flexible joint and the variable stiffness manipulator allow dynamic adjustment of the stiffness to adapt to different tasks. The variable stiffness gripper serves as an end effector and directly contacts objects. The entire system is installed on the frame, realizing structural stability and modular design, and can comprehensively evaluate the performance of the manipulator and the gripper. The invention provides a rope-driven test system that is comprehensive in function, flexible in operation and convenient to maintain, and can effectively test and verify the performance of the variable stiffness manipulator and the gripper, providing important technical support for practical applications.

The present invention discloses a variable stiffness integral soft finger and a finger trainer. The variable stiffness integral soft finger includes a base structure, a through hole, a variable stiffness structure and a fingertip structure. One end of the base structure is connected to the through hole, one end of the variable stiffness structure is connected to the other end of the base structure, and the fingertip structure is connected to the other end of the variable stiffness structure. A cavity structure is formed between the through hole, the base structure, the variable stiffness structure and the fingertip structure. The structure of the present invention has a high degree of anthropomorphism. When a load is applied, it can achieve different bending profiles with variable stiffness. Its internal stress distribution is uniform, stress concentration is small, deformation is coordinated, and the service life is long. It adopts an integral molding structure, which fits the fingers well and can adapt to the hand sizes of different people.

This invention provides a hybrid soft-hard gripper with variable stiffness, comprising multiple fingers. Each finger is constructed from a rigid, hyper-redundant internal skeleton with more degrees of freedom than required for the grasping task. In this way, the fingers of the hybrid soft-hard gripper can adapt to the shape of objects with complex geometries, mimicking the advantages of soft grippers. Furthermore, the rigid internal skeleton allows for the generation of the necessary stiffness to achieve high precision and payload during grasping operations. On the other hand, this invention places actuators at the bottom of the gripper, while allowing them to be remotely controlled via lightweight cables, overcoming the space and weight limitations imposed by actuators. The design of the hybrid soft-hard gripper also incorporates the integration of tactile sensors, providing force / slip feedback during grasping operations.

The invention relates to the technical field of power generation systems, in particular to a power generation system based on a variable-stiffness hydraulic spring type symmetrical free plunger expansion machine, which comprises a variable-stiffness hydraulic spring type symmetrical free plunger expansion machine set, an expansion machine initialization hydraulic set, a self-matching generator set and a buffer tank assembly, the adopted variable-stiffness hydraulic spring type symmetrical free plunger expansion machine has the advantage of being adaptive to changes of working conditions such as air inlet pressure and flow, and the free plungers at the symmetrical ends can return to the top end every time no matter whether the free plungers reach the bottom dead center or not, so that the energy loss during air inlet is reduced; the free plunger has the advantages of being simple in structure, resistant to high pressure and multiphase flow, high in pollution resistance and the like, and recycling, application and popularization of pressure difference energy of natural gas or other gases are facilitated. According to the invention, the pressure difference energy of natural gas or other high-pressure gas can be utilized to generate power, so that efficient utilization of energy is realized.

The application provides a design method of a soft grabbing robot, which comprises the following steps: firstly, different hybrid variable stiffness mechanisms are designed, and corresponding hybrid variable stiffness soft actuators are prepared; then, a pneumatic driving test platform and a variable stiffness performance test platform are built; then, the bending performance test and the stiffness test are performed on each hybrid variable stiffness soft actuator; finally, the bending performance and the variable stiffness capacity of the hybrid variable stiffness soft actuators are compared and analyzed, and the hybrid variable stiffness soft actuator with the best comprehensive performance is selected. Three different actuators are prepared, the pneumatic driving test platform and the variable stiffness performance test platform are built, and the bending performance test and the stiffness test are performed on the three prepared hybrid variable stiffness soft actuators, so that the bending performance and the variable stiffness performance are simultaneously considered.