CN111993462A - Flexible mechanical arm based on SMA drive multi-section rigid-flexible coupling - Google Patents
Flexible mechanical arm based on SMA drive multi-section rigid-flexible coupling Download PDFInfo
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Abstract
The invention discloses a flexible mechanical arm based on SMA drive multi-section rigid-flexible coupling, wherein a flexible joint of the flexible mechanical arm is driven by an SMA material, and a joint structure unit is composed of a base body for fixing and connecting and an active section for realizing flexible bending. The flexible mechanical arm driven by SMA and coupled in a rigid-flexible mode is adopted, and the flexible mechanical arm is bent and deformed to different degrees by changing the design of SMA driving current and SMA wire distribution flexible joints. The design can effectively improve the bending deformation characteristic of the flexible mechanical arm, and has important significance for wide application of the flexible mechanical arm.
Description
Technical Field
The invention is mainly applied to the field of robots, and particularly relates to a rigid-flexible coupling mechanical arm based on SMA drive.
Background
With the continuous development of the robot technology, the mechanical arm is widely applied in various industries, particularly in the fields of intelligent manufacturing, industrial automation, aerospace and the like. In the traditional industrial field, the mechanical arm is driven by a rigid joint, the high-precision control of the position and the speed of the tail end can be realized, the motion trail is accurately tracked, and the response speed is high. However, the mechanical arm has the defects of large mass and volume, high output rigidity, weak adaptability to unknown environment and the like. However, when the mechanical arm is gradually applied to other non-industrial fields such as service, medical treatment and entertainment, the working environment at the tail end of the mechanical arm is often in contact, or when the mechanical arm is applied to unknown environments such as dangerous environment detection, that is, when special requirements such as a motion track of the mechanical arm cannot be planned in advance, the flexible mechanical arm is produced accordingly, and the flexible mechanical arm has the advantages of compact structure, good flexibility, higher load/dead weight ratio and better environment interaction capacity.
As new types of elastic elements or flexible mechanisms are increasingly applied to robotic arms, flexible arms with variable or continuously adjustable stiffness have emerged. The development of such flexible arms aims to be comparable with human arms in terms of dexterity and perceptibility, and eventually can gradually replace human work. Therefore, the research on the flexible mechanical arm with human muscle-like characteristics has important practical significance for improving the safety and environmental adaptability of the robot and better serving human beings in the future.
Combining robotics, elastomechanics, intelligent control and other technologies, bionics people develop various different types of flexible mechanical arms. The flexible mechanical arm has three driving modes of an embedded type, an external type and a mixed type according to different driver distribution conditions. The embedded type is driven by pneumatic muscle or Shape Memory Alloy (SMA) and is arranged in the mechanical arm, for example, a pneumatic elephant-nose type mechanical arm developed by German Festo company, an 'octopus tentacle' mechanical arm developed by MIT computer science and artificial intelligence laboratories, and the like. The external robot mainly uses an external motor to pull a cable to drive a robot joint, such as a snake-shaped arm robot developed by OC Robotics of England, the robot has 10 sections, each section has 2 degrees of freedom, and the robot is driven by the motor. The hybrid drive has both an embedded drive structure and an external drive structure, such as an Air-inductor robot developed by McMahan et al, the hybrid drive has a structure divided into 4 sections, the bending angle of each section is greater than 100 degrees, and the robot introduces pneumatic drive and cable drive at the same time.
Currently, the intelligent materials that have been applied to the design of the bionic machinery mainly include three types, i.e., ion-exchange Polymer-Metal Composite (IPMC), Piezoelectric Ceramics (PZT), and Shape Memory Alloy (SMA). The PZT requires a large driving voltage of 50-800V generally, has a small deformation amount which is only one thousandth of the size of the PZT, and often needs to be additionally designed with a mechanism to amplify the strain, so that the PZT is less applied to the design of a bionic mechanical arm. While IPMC has the advantages of low driving voltage, fast response and low energy consumption, and is widely applied to the design of bionic machinery, the driving force is small, so that the currently developed IMPC-driven mechanical structure is difficult to be put into practical use. And besides the advantages of low driving voltage and maximum deformation, the SMA also has the advantages of large output force and high power-weight ratio, and the performance of the SMA is most connected with the performance of biological muscle fibers, so that compared with other intelligent materials, the SMA has better comprehensive performance and is more suitable for being applied to the driving design of bionic machinery.
SMA is an alloy with shape memory effect, i.e. the shape of the alloy is changed and then it can return to its original shape when heated to a certain transition temperature, and an alloy with this special function is called a shape memory alloy. The shape memory effect of an alloy is a particular thermo-mechanical behavior that is the result of a reversible transformation of the low temperature phase (martensite) produced by a thermo-elastic martensitic transformation to the high temperature phase (austenite) upon heating. The shape memory alloy can be used as a driving element by utilizing the characteristic that the shape memory alloy can do work to the outside by the restoring force while the shape memory alloy recovers the shape when being heated. SMA's are metallic in nature and have metallic electrical conductivity, so the SMA actuator can be driven by electrical heating. The strain of SMA can reach 8%, the stress can reach 500MPa, and the SMA is easy to drive and has lower driving voltage, so that the SMA can be widely applied to bionic design.
Therefore, the SMA has a very wide application prospect in the field of flexible mechanical arms, but no corresponding technical achievement is generated in the prior art at present.
Disclosure of Invention
The invention aims to provide a rigid-flexible coupling mechanical arm based on SMA drive, which has the advantages of light weight, high flexibility, good flexibility and the like, can greatly reduce the rigidity of a joint, and can complete a complex contact task.
The mechanical arm is driven by SMA material, and has the advantages of large output stress, large strain and low driving voltage. The flexible mechanical arm can realize large-amplitude bidirectional flexible bending under the drive of current, and has the advantages of good bending effect, simple structure and noiseless action.
Different from the existing flexible mechanical arm mechanism, the invention provides a multi-section rigid-flexible coupling flexible mechanical arm, and the flexible structure of the mechanical arm utilizes the characteristic deformation of an SAM material body to realize the continuous bending of the mechanical arm so as to form the movement similar to a trunk and an octopus tentacle. By changing the appearance of the mechanical arm, the flexible robot can flexibly bypass various obstacles or pass through narrow and curved holes, and is very suitable for application in unstructured environments and space-limited environments. Besides, the flexible robot can also realize the grabbing of the object only through the body, similar to the action of the elephant grabbing food through the nose. The excellent performances enable the flexible robot to have great application prospects in the fields of aviation detection, medical surgery, urban rescue, industrial manufacturing, agricultural production and the like.
The flexibility of the flexible mechanical arm mainly comes from the flexibility of a plurality of joints driven by SMA, and the flexibility of the joints is an additional degree of freedom introduced into the mechanical arm, so that the original limited degree of freedom is changed into an infinite degree of freedom. The links of the flexible robotic arms are rigid, flexible and exist only at the joints.
The flexible joint of the flexible mechanical arm is driven by SMA material, and the joint structure unit mainly comprises a base body for fixing and connecting and an active section for realizing flexible bending. The active section mainly comprises SMA wires, an elastic body and a viscoelastic flexible covering material (such as polyethylene plastic and the like), wherein the SMA wires are folded into a plurality of U-shaped arrays, the closed ends of the U-shaped arrays are adhered to the elastic body, and the open ends of the U-shaped arrays are fastened on the base body through bolts and connected with two conducting wires. The elastic body is symmetrically provided with an array SMA wire in a shape like a U on two sides, and then the SMA wire is covered on the elastic body by a viscoelastic material. Because the two ends of the SMA wire are fixed, the elastic body and the skin are bent by the contraction of the SMA wire, and the larger the contraction strain is, the larger the bending angle is. The main function of the elastomer is to provide a resisting moment when the SMA wire contracts so that it does not suffer from the problem of buckling, and a restoring moment when the SMA wire is strain-recovered, and therefore, the elastomer is required to have a suitable modulus of elasticity.
The viscoelastic material of the flexible mechanical arm is used for covering the SMA wire, and the SMA wire is fixed on the elastic body in the process. When the flexible joint driven by the SMA deforms, the viscoelastic material stores and releases elastic energy in the bending and recovery processes of the joint, plays a role in storing energy and provides power for the recovery of the bending of the flexible mechanical arm joint.
The flexible mechanical arm is simulated by using the multi-section rigid-flexible coupling structure driven by the SMA, and the deformation curve of the mechanical arm is changed by changing the driving current, so that the bending deformation of the flexible mechanical arm is realized.
The flexible mechanical arm can realize different bending deformations through the optimization of SMA wire parameters and distribution array parameters, and obtain better control performance.
The invention aims to solve the problem of accurate pose control of the flexible mechanical arm through the SMA wire drive and provides an effective engineering solution for the pose control of the flexible mechanical arm.
The flexible mechanical arm can realize rigidity characteristic by changing the physical properties of the viscoelastic covering material of the flexible joint, and the bending deformation of the flexible mechanical arm depends on physical parameters such as Young modulus, length, section inertia moment and the like of the material. Thus, the bending stiffness of the robot arm can be achieved by changing the physical parameters.
Specifically, the flexible mechanical arm comprises a mechanical arm fixing platform, a rigid mechanical structure, an SAM driving flexible joint, a programmable power supply, a displacement or speed sensor, a controller, an arm end tool and the like. The upper end and the lower end of each flexible joint are respectively fixed on the rigid mechanical arm structure, and the lower end of each flexible hinge penetrates through a hinge point hole on the rigid mechanical arm and is fixedly connected with the speed/displacement combined sensors; the flexible joint is used for changing the deformation curve or deformation displacement of the flexible mechanical arm, and the deformation condition depends on the driving current of the SMA and the SMA wire distribution array of the SMA driving system. The flexible mechanical arm is based on a multi-section flexible joint structure and is driven by SMA to realize bending deformation. The flexible mechanical arm driven by the SMA can be composed of a plurality of SMA wires, and different array types and structural parameters exist. The flexible joints can be multiple, the more flexible hinges are, the shorter the rigid mechanical arm is, the more controllable the deformation of the flexible mechanical arm is, and the more accurate the mechanical arm control is.
The invention has the advantages that:
compared with the design method of the existing industrial mechanical arm, the rigid-flexible coupling flexible mechanical arm driven by SMA is adopted, and the flexible mechanical arm is bent and deformed to different degrees by changing the design of SMA driving current and SMA wire distribution flexible joints. The design can effectively improve the bending deformation characteristic of the flexible mechanical arm, and has important significance for wide application of the flexible mechanical arm. The method has the advantages that:
(1) the SMA is adopted to drive the plurality of flexible joints to achieve good flexibility and high flexibility of the mechanical arm, so that the rigidity of the joints can be greatly reduced, and a complex contact task is completed. The mechanical arm is driven by SMA material, and has the advantages of large output stress, large strain and low driving voltage. Under the drive of current, the mechanical arm can realize large-amplitude bidirectional flexible bending and has the advantages of good bending effect, simple structure and noiseless action.
(2) The bending deformation control of the flexible mechanical arm can be realized by changing the drive current of the SMA in the flexible joint. The distribution of the SMA system in the flexible joint and the size of the elastic structure are optimized, so that the effective control of the bending deformation of the flexible mechanical arm is realized.
Drawings
FIG. 1 is a general schematic view of a flexible robot arm according to the present invention
FIG. 2 is a schematic diagram of an undeformed state of the multi-channel flexible hinge structure;
FIG. 3 is a schematic diagram of a deformation state of the multi-channel flexible hinge structure;
FIG. 4 is a top view of FIG. 2;
FIG. 5 is a schematic diagram of an undeformed state of a flexible manipulator structure of the SMA drive structure;
FIG. 6 is a schematic view of the heating state of the SMA wire on the A surface;
FIG. 7 is a schematic cross-sectional view of a flexible robotic arm unit;
FIG. 8 is a schematic diagram of the SMA drive principle of the flexible mechanical arm;
FIG. 9 shows control signals for SMA wires on the A side and the B side of the mechanical arm;
FIG. 10 is a block diagram of the hardware configuration of the robot arm control system;
FIG. 11 is a block diagram of a hardware structure of a bending performance testing system of a flexible manipulator;
FIG. 12 is a block diagram of a main program flow of a main control chip of a robot arm.
The labels in the figures are: the method comprises the following steps of 1-fixing a support, 2-flexible arm SMA driving section I, 3-flexible arm SMA driving section II, 4-flexible arm SMA driving section III, 5-flexible arm SMA driving section IV, 6-flexible arm SMA driving section V, 7-tail end executing piece, 8-mechanical arm base body, 9-elastic body, 10-A surface SMA wire, 11-B surface SMA wire, 12-viscoelastic material, 13-elastic sheet and 14-SMA wire.
Description of the reference numerals
An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.
The invention is realized by adopting the following technical scheme:
the flexible hinge of the SMA-driven rigid-flexible coupling structure is used as a basis, and the flexibility and the bending deformation control of the mechanical arm are realized by connecting the rigid part of the mechanical arm.
One embodiment is shown in FIG. 1: the device comprises a fixed support 1, an SMA driven flexible hinge, a tail end executing part 7 and the like, and further comprises a programmable power supply, a sensor, a controller and the like. The flexible hinge driven by the SMA can be divided into a flexible arm SMA drive I section 2, a flexible arm SMA drive II section 3, a flexible arm SMA drive III section 4, a flexible arm SMA drive IV section 5, a flexible arm SMA drive V section 6 and the like. Besides the advantages of large motion space and high positioning precision of the mechanical arm, the flexible mechanical arm has the characteristics of inherent flexibility, output stress and strain of the SMA driving system and low driving voltage. In addition, the bending deformation of the whole mechanical arm can be changed, so that the rigidity of a contact interface of the mechanical arm and the environment is matched in real time.
The following further illustrates the practice of the present invention:
according to the design task of the mechanical arm, the trajectory planning of mechanical arm deformation is analyzed, the number of sections of the rigid mechanical arm and the length of each section of the mechanical arm are designed, and parameters such as the mass, the section size and the moment of inertia of each section of the mechanical arm are designed.
And designing an SMA-driven flexible joint structure of the flexible hinge of the mechanical arm according to the planned track of the mechanical arm. The SMA driving flexible joint structure mainly comprises a flexible deformation elastic layer, namely an elastic body 9, and SMA layers on two sides (an A surface SMA wire 10 and a B surface SMA wire 11). The main parameters of the SMA driving deformation layer design mainly comprise an SMA arrangement array, the diameter and the length of an SMA wire 14, the elastic modulus of the viscoelastic material 12, the thickness of the elastic sheet 13 and the like. The structural diagrams corresponding to the undeformed state and the deformed state of the SMA driving flexible mechanical arm are respectively shown in the attached figures 2-3.
As shown in fig. 2-7, the SMA wire is in a pre-stretched state before heating, when the SMA wire on one side is electrified and heated, the temperature of the SMA wire rises and martensite reverse phase transformation occurs, and meanwhile, the SMA wire starts to shrink, when the temperature reaches the austenite phase transformation finishing temperature, the shrinkage strain of the SMA wire reaches the maximum, and the SMA wire outputs restoring force in the shrinking process. Due to the biased arrangement of the SMA wires in the flexible robot arm unit, a bending moment is provided to the elastic body 9. Under the action of bending moment, the elastic body 9 bends to one side of the electrified SMA wire. Because the thicknesses of the elastic body 9 and the skin are smaller, the flexible mechanical arm unit can be bent greatly. And then the SMA wire is powered off and cooled, the temperature of the SMA wire is reduced, the martensite phase transformation occurs, the recovery stress of the SMA wire is reduced, the elastic energy stored in the elastic body 9 and the skin is released, and the flexible mechanical arm unit is restored under the driving of the elastic energy and the skin. And then the SMA wire on the other side is electrified, the flexible mechanical arm unit is bent towards the other side, the SMA wire is powered off, and the flexible mechanical arm unit is restored to the original state again. When the SMA wires on the two sides are alternatively powered on and powered off, the flexible mechanical arm unit can realize flexible bidirectional bending.
The flexible mechanical arm based on SMA drive is driven by current heating, and the magnitude of the drive current can influence the bending angle which can be achieved by the flexible mechanical arm, so that a mathematical model between the drive current of the flexible mechanical arm and the bending angle of the flexible mechanical arm needs to be established. The analysis concept is shown in the attached figures 2-4.
The stress analysis of the flexible mechanical arm is used for establishing the relation between the stress strain of the SMA wire. The stress analysis of the flexible mechanical arm can be divided into two conditions of keeping static bending and moving. The stress condition of the flexible mechanical arm when the flexible mechanical arm keeps static bending is analyzed, and the flexible mechanical arm keeps static and only keeps bending under the action of the SMA wire. Wherein, the SMA wire on one side is electrified and contracted to generate contraction stress, the SMA wire on the other side is stretched to generate tensile stress, and the stress of the SMA wire acts on the elastic body 9. Since the stress direction is parallel to the surface of the elastic body 9, it can be considered that the elastic body 9 is only subjected to a pure bending moment, and therefore, the bending of the flexible mechanical arm in a static state is the pure bending of the beam. According to the pure bending model of the beam, the neutral layer of the beam does not shift, and the curvature of the neutral layer is as follows:
where ρ is the neutral layer radius of curvature (m);
m-pure bending moment acting on the beam (N M);
e-modulus of elasticity (Pa);
i-moment of inertia (N m 2).
Wherein the pure bending moment M is:
M＝(FA-FB)×dc
in the formula FAThe flexible mechanical arm receives a resultant force (N) generated when the SMA wire on the side A contracts;
FBthe flexible mechanical arm receives a resultant force (N) generated when the SMA wire at the side B is stretched;
d is the distance (m) between the acting point of the resultant force and the central axis of the flexible mechanical arm.
FAAnd FBCan be calculated from the following equations:
in the formula sigmaA-stress (Mpa) generated when the SMA wire of side a contracts;
σB-the SMA wire on the B side is stretchedStress (Mpa) generated;
ds-diameter of SMA wire (m);
n is the number of SMA wires distributed on two sides.
The stress and strain relation of the SMA wire at the A side is controlled by an SMA constitutive model, and the SMA wire at the B side is stretched at normal temperature, so that the stress and strain of the SMA wire at the A side accord with Hooke's law:
σB＝BDM (4)
in the formula sigmaB-strain of side B SMA wires;
DMmodulus of elasticity (MPa) when the SMA is in the fully martensitic state.
The bending stiffness of the flexible manipulator is calculated in two parts as follows:
EI＝ErITz+EMIMz (5)
in the formula ET、EM-the elastic modulus (MPa) of the elastomer and the skin, respectively;
ITz、IMzthe moments of inertia of the cross-sections of the elastomer and the skin, respectively, about the z-axis (N m)2)。
ITzAnd IMzRespectively as follows:
w — width (m) of flexible robotic arm unit;
hm-thickness (m) of the one-sided skin;
ht-thickness (m) of the elastomer.
Since the neutral layer length remains constant during bending, there are:
L＝ρθ (8)
wherein L is the length (m) of the flexible arm bending unit;
ρ — neutral layer radius of curvature (m);
θ — Angle of curvature (rad).
By definition of strain, a relationship between SMA wire strain and radius of curvature can be established as follows:
wherein
In the same way, the strain of the SMA wire at the B side is
Curvature radius rho and bending angle theta of flexible mechanical arm and strain of heated SMA wireAThe relationship between, namely:
the above formula shows the bending angle theta of the flexible mechanical arm and the strain of the heated SMA wireAIn a linear decreasing relationship. When in useAWhen the bending angle is zero, the maximum bending angle of the flexible mechanical arm is obtained by the formula (13):
obtaining the stress sigma of the heated SMA wireAAnd strainAThe relationship between them is as follows:
wherein K is:
as shown in the formula (15), the stress σ of the heated SMA wireAAndAin a linear decreasing relationship whenAWhen the bending angle is zero, the stress when the flexible mechanical arm reaches the maximum bending angle can be obtained according to the formula (15):
firstly, a propulsion performance testing system of a flexible mechanical arm is built, the hardware structure composition block diagram of the system is shown as the attached figures 10-11, and the system can be functionally divided into three functional units, namely a driving control unit, a thrust measurement unit, a signal acquisition display unit and the like. The driving control unit is used for driving the flexible mechanical arm and controlling the swinging amplitude and frequency of the flexible mechanical arm, the thrust measuring unit is used for measuring the generated thrust and converting the thrust into a voltage output signal, and finally the signal acquisition and display unit is used for acquiring, processing, displaying and storing the voltage signal.
The core of the driving control unit is a self-designed driving circuit, the function of the driving control unit is to realize the control of heating and cooling of the SMA wires embedded in two sides of the flexible mechanical arm, the principle is shown in the attached figures 8-9, an MOSFET is connected in series in a heating loop of the SMA wires, the on-off of the heating loop is controlled through the on-off of the MOSFET, so that the heating and cooling of the SMA wires are controlled, and a control signal is generated by a microcontroller in the driving circuit.
Control signals of the SMA wires on the two sides of the flexible mechanical arm are shown in FIGS. 8-9, wherein ton is the pulse width of energization, and determines the heating time of the SMA wires, i.e. the swing time of the flexible mechanical arm, and also determines the swing amplitude; toff is an electrified pulse interval and determines the cooling time of the SMA wire, namely the backswing time of the flexible mechanical arm. twice the sum of ton and toff is the period T, which determines the period of oscillation of the flexible robot arm. The swing amplitude and swing frequency of the flexible mechanical arm can be controlled by controlling the parameters ton and toff.
The hardware structure block diagram of the flexible mechanical arm control system is shown in fig. 10-11, and the flexible mechanical arm control system mainly comprises functional modules such as a communication module, a driving module, an inertial navigation module, a current detection module and the like except for a main control chip. The communication module has the functions of realizing communication with the upper computer and receiving a control instruction of the upper computer, thereby realizing remote control on the micro mechanical arm. The driving module is used for realizing the driving control of the flexible mechanical arm according to the parameters set by the program. The inertial navigation module has the functions of realizing the real-time detection of the motion direction and the motion state of the mechanical arm and providing a foundation for the motion control and the autonomous swimming of the micro mechanical arm. The current detection module has the functions of detecting the driving current of the flexible mechanical arm, providing a foundation for motion control of the flexible mechanical arm and giving an alarm when the detected current is smaller than the minimum driving current.
Because the internal volume of the flexible mechanical arm is limited, and only a battery with smaller volume and capacity can be carried as a power supply source of the flexible mechanical arm, a chip with smaller power consumption is selected when the main control chip is selected so as to reduce the energy consumption of the flexible mechanical arm. The communication module can be realized by a wireless serial port receiving and transmitting module consisting of a high-performance singlechip and a low-power-consumption radio frequency chip. The driving module is composed of a power MOSFET and a driver thereof, the MOSFET is connected in series in a heating loop of the SMA wire, and a main control chip generates a control signal to control the on-off of the MOSFET so as to control the heating and cooling of the SMA wire. The driving circuit consists of a TC4427 chip and an FDS6912 chip. The current detection module is implemented by a linear hall sensor ACS712 chip.
The programming of the main control chip of the flexible mechanical arm comprises main program design and each interruption subprogram design. Fig. 12 shows a flow chart of the lower computer main program. The tasks to be realized by the main program include analyzing the control instruction, starting or stopping each functional module, calculating the current pose information in real time, adjusting the control parameters according to an autonomous swimming strategy and the like. The flexible mechanical arm is driven by a timer interrupt. When the driver module is started, a timer interrupt is started. The timer generates 1ms periodic interruption, a counter is arranged in the interruption program for accumulation, and when the value of the counter is equal to the driving pulse width or period, the level of the corresponding driving I/O port is turned over, so that the flexible mechanical arm is driven. The counter is cleared when it is equal to the drive period. The data of the wireless module and the inertial navigation module are received by different serial ports in an interruption mode, and the acquisition of the driving current is realized by A/D interruption.
The above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and variations, modifications, additions and substitutions which may be made by those skilled in the art within the spirit of the present invention are within the scope of the present invention.
Claims (8)
1. The utility model provides a flexible arm based on SMA drive multistage rigid-flexible coupling which characterized in that: the flexible joint of the flexible mechanical arm is driven by SMA material, and the joint structure unit is composed of a base body for fixing and connecting and an active section for realizing flexible bending.
2. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 1, wherein: the active section consists of components including SMA wires, an elastic body and a viscoelastic flexible covering material, wherein the SMA wires are folded into a plurality of U-shaped arrays, the closed ends of the U-shaped arrays are adhered to the elastic body, and the open ends of the U-shaped arrays are fastened on the substrate through bolts and connected with two leads; the elastic body is symmetrically provided with SMA wires in a U-shaped array at two sides, and then the SMA wires are covered on the elastic body by viscoelastic materials.
3. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 2, wherein: a flexible mechanical arm is simulated by using an SMA-driven multi-section rigid-flexible coupling structure, and a deformation curve of the mechanical arm is changed by changing driving current.
4. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 2, wherein: the flexible mechanical arm manufactured by optimizing the parameters of the SMA wires and the parameters of the distributed array realizes different bending deformations.
5. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 2, wherein: the flexible mechanical arm manufactured by optimizing the parameters of the SMA wires and the parameters of the distributed array realizes different bending deformations.
6. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 2, wherein: the accurate pose control of the flexible mechanical arm is achieved through the SMA wire drive.
7. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 2, wherein: the stiffness characteristic is achieved by changing the physical properties of the viscoelastic cover material of the flexible joint.
8. The flexible mechanical arm based on the SMA drive multi-section rigid-flexible coupling of claim 1, wherein: the flexible mechanical arm comprises a mechanical arm fixing platform, a rigid mechanical structure, an SAM driving flexible joint, a programmable power supply, a displacement or speed sensor, a controller and an arm end tool; the upper end and the lower end of the SAM driving flexible joints are respectively fixed on the rigid mechanical structure, and the lower ends of the flexible hinges of the SAM driving flexible joints penetrate through hinge point holes in the rigid mechanical arm and are fixedly connected with the displacement or speed sensors.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114955021A (en) * | 2022-06-14 | 2022-08-30 | 南京航空航天大学 | Octopus tentacle-imitating space catching mechanism |
| CN115885694A (en) * | 2022-12-21 | 2023-04-04 | 东北林业大学 | Lifting device for utilize corrugated sheet elastic deformation to independently avoid barrier and initiatively pick based on coiling lift principle |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110202563A (en) * | 2019-07-01 | 2019-09-06 | 贵州理工学院 | A kind of flexible mechanical arm based on SMA driving multistage Coupled Rigid-flexible |
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110202563A (en) * | 2019-07-01 | 2019-09-06 | 贵州理工学院 | A kind of flexible mechanical arm based on SMA driving multistage Coupled Rigid-flexible |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114955021A (en) * | 2022-06-14 | 2022-08-30 | 南京航空航天大学 | Octopus tentacle-imitating space catching mechanism |
| CN114955021B (en) * | 2022-06-14 | 2024-05-14 | 南京航空航天大学 | Octopus-like tentacle space capturing mechanism |
| CN115885694A (en) * | 2022-12-21 | 2023-04-04 | 东北林业大学 | Lifting device for utilize corrugated sheet elastic deformation to independently avoid barrier and initiatively pick based on coiling lift principle |
| CN115885694B (en) * | 2022-12-21 | 2023-08-11 | 东北林业大学 | Lifting device based on winding lifting principle and capable of automatically avoiding obstacle and actively picking by utilizing elastic deformation of corrugated sheet |
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Application publication date: 20201127 |