CN113199470B

CN113199470B - Gripping device and control method of soft mechanical arm

Info

Publication number: CN113199470B
Application number: CN202110340091.3A
Authority: CN
Inventors: 王峥; 方忠桂; 刘思聪; 黄超逸; 陈奕杉; 汤凯栾; 郑曲乐
Original assignee: Shenzhen Renzhi Technology Co ltd
Current assignee: Shenzhen Renzhi Technology Co ltd
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2022-08-30
Anticipated expiration: 2041-03-30
Also published as: CN113199470A

Abstract

The application relates to a gripping device and a control method of a soft mechanical arm, wherein the control method comprises the following steps: acquiring first posture information for describing a target posture of the soft mechanical arm; obtaining a target pressure value in the soft driver according to the first attitude information; changing the driving force acting on the soft actuator according to the target pressure value to control the expansion and contraction of the soft actuator; acquiring parameter information of the soft driver, wherein the parameter information at least comprises the length of the soft driver and an actual internal pressure value; obtaining second attitude information for representing the current attitude of the soft mechanical arm according to the parameter information; comparing the first attitude information with the second attitude information to obtain a first comparison result; adjusting the driving force applied to the soft driver at least according to the first comparison result. The control method can more accurately control the posture of the soft mechanical arm.

Description

Gripping device and control method of soft mechanical arm

Technical Field

The invention relates to the technical field of robots, in particular to a gripping device and a control method of a soft mechanical arm.

Background

With the development and popularization of the industrial process, the rigid mechanical arm is deeply researched and well applied to industrial structural scenes such as industrial grabbing and sorting. Due to the fact that the rigidity of the rigid mechanical arm is too large, the safety and interaction capacity of the rigid mechanical arm are low in the using process, and the control accuracy, stability, robustness and the like have to be improved at the cost of reducing the overall working speed of the rigid mechanical arm in practical application. Nevertheless, safety accidents due to rigid mechanical arms in industrial applications are still occurring every year.

In recent years, as the soft robot is concerned and researched by scholars at home and abroad, the soft mechanical arm designed based on the soft robot concept has the inherent natural flexibility of the soft robot, provides safety in an interaction process, provides possibility for the application of the mechanical arm to an unstructured scene, simultaneously has extremely high design flexibility, is flexible in arrangement of a transmission mechanism, and can realize complex/multi-coupling/high-flexibility movement which is difficult to realize by a rigid structure.

The flexible mechanical arm is formed by connecting a plurality of flexible drivers, the flexible mechanical arm moves through the deformation of the flexible drivers, and compared with the rigid mechanical arm, the driving/control algorithm of the flexible mechanical arm has great difference.

Disclosure of Invention

The invention mainly solves the technical problems that: how to better control the motion posture of the soft mechanical arm. To solve the above problems, the present application provides a gripping device and a method for controlling a soft mechanical arm.

According to a first aspect, an embodiment provides a control method of a soft mechanical arm, the soft mechanical arm comprises a plurality of soft drivers and a plurality of rigid connecting pieces, the rigid connecting pieces are connected through the soft drivers, the soft drivers are arranged in a telescopic structure through changing the internal pressure of the soft drivers by driving force, and the posture of the soft mechanical arm is controlled through the telescopic of the soft drivers;

the control method comprises the following steps:

acquiring first posture information for describing a target posture of the soft mechanical arm;

obtaining a target pressure value in the soft body driver according to the first attitude information;

changing the driving force acting on the soft actuator according to the target pressure value so as to control the expansion and contraction of the soft actuator;

acquiring parameter information of the soft body driver, wherein the parameter information at least comprises the length of the soft body driver and an actual pressure value inside the soft body driver;

obtaining second posture information used for representing the current posture of the soft mechanical arm according to the parameter information;

comparing the first attitude information with the second attitude information to obtain a first comparison result;

adjusting the driving force applied to the soft driver at least according to the first comparison result.

According to a second aspect, there is provided in an embodiment a grasping apparatus including:

the soft mechanical arm comprises a plurality of soft drivers and N layers of link units distributed along an axial hierarchy, wherein the soft drivers are all arranged to be of a telescopic structure by changing the internal pressure of the soft drivers through a driving force, each soft driver comprises a circumferential driver and an axial driver, each link unit comprises at least three rigid connecting pieces used for forming a bayonet, adjacent rigid connecting pieces in each link unit are connected through the circumferential drivers and are close to or far away from each other under the driving of the circumferential drivers, so that the bayonets are expanded or reduced, adjacent link units are connected through the axial driving pieces and are close to or far away from each other under the driving of the axial drivers, and the link units on the Nth layer are used for grabbing target objects outside the soft mechanical arm by reducing the bayonets;

the control system is used for being respectively connected with the plurality of soft drivers in the soft mechanical arm and applying driving force to the soft drivers;

and the processing system is in communication connection with the control system and is used for controlling the soft mechanical arm by the method of the embodiment.

According to a third aspect, an embodiment provides a computer-readable storage medium having a program stored thereon, the program being executable by a processor to implement the method of the above-described embodiment.

The beneficial effect of this application lies in:

firstly, a data set of the internal pressure value and the length of each software driver can be monitored and fed back in real time, so that the whole attitude information of the software mechanical arm is synthesized, and the body perception of the software mechanical arm is realized.

And secondly, a positive and negative solution between the target gesture input by the user and the target pressure value of each software driver required to be driven is realized, and the possibility is provided for real-time display and interaction of gesture information, real-time control of the software drivers and the like.

Thirdly, the difference between the current state and the target posture can be guided in real time through the first comparison result of the first posture information and the second posture information, and then the next driving strategy is guided, so that more accurate control can be carried out.

Drawings

FIG. 1 is a schematic view of a grasping apparatus according to an embodiment;

FIG. 2 is a schematic diagram of one embodiment of a soft robot;

FIG. 3 is a schematic view of a soft arm in a bending state according to an embodiment;

FIG. 4 is a schematic view of an embodiment of a soft mechanical arm link unit separated from an axial unit;

FIG. 5 is a schematic view of the structural assembly of the rigid link of one embodiment of the soft robotic arm;

FIG. 6 is an exploded view of one embodiment of the rigid linkage of the soft robotic arm;

FIG. 7 is a schematic diagram showing an exploded view of the rigid link of the soft robotic arm according to one embodiment;

FIG. 8 is a flowchart of the method for controlling the robotic arm in spatial motion mode according to one embodiment;

FIG. 9 is a flowchart of a method for controlling the soft robotic arm in a swallowing grasping mode according to an embodiment;

FIG. 10 is a flow chart of the single layer transfer step of one embodiment.

10. An axial driver;

20. a circumferential drive;

30. a rigid connection member;

31. a base member; 31-1, a base part; 31-2, a linking arm part; 31-3, a second fastener; 31-4, a fourth fastener;

32. a seat plate member; 32-1, a first fastener;

33. a contact pressing piece; 33-1, a third fastener; 33-2, an end cap portion; 33-3, an anti-skid part;

40. a bayonet;

A. a software driver; B. a link unit; C. an axial unit; d. an axial end face; e. a circumferential end face; f. an inner ring end face;

100. a soft mechanical arm;

200. a control system;

210. a lower computer;

220. a bottom drive system;

300. a processing system;

310. an upper computer;

400. a target object.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in this specification in order not to obscure the core of the present application with unnecessary detail, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the described features, operations, or characteristics may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various orders in the specification and drawings are for clarity of description of certain embodiments only and are not meant to imply necessary orders unless otherwise stated where a certain order must be followed.

The ordinal numbers used herein for the components, such as "first," "second," etc., are used merely to distinguish between the objects described, and do not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

The soft body driver A is prepared by soft body materials (such as Dielectric Elastomer (DE), ionic polymer metal composite material (IPMC), Shape Memory Alloy (SMA), Shape Memory Polymer (SMP) and the like), can generate linear telescopic motion outwards under fluid drive (such as air pressure/hydraulic drive and the like, wherein the air pressure drive is mainly taken as an example in the invention), and can generate bending deformation due to the properties of the soft body materials. For example, when an external revolute pair constraint is applied to the soft driver A, the soft driver A can generate the rotary motion output around the revolute pair under the pneumatic driving effect. In the soft mechanical arm 100, each soft actuator a may be communicated with an external fluid actuator through an independent fluid pipeline, and the fluid medium provided by the fluid actuator changes the pressure inside the soft actuator a, thereby generating an expansion or contraction structural deformation effect, so as to achieve the purpose that the soft actuator a outputs power while expanding and contracting, for example, the soft actuator a may include an expansion member integrally formed by a flexible material such as plastic through processes such as blow molding, injection molding, 3D printing, etc., the expansion member may have a bellows type, paper folding type or other tubular structure with a certain structural expansion performance, the expansion member has a fluid chamber therein communicated with the fluid pipeline, and the fluid pressure inside the fluid chamber may be changed during the process of the fluid medium entering and exiting the fluid chamber, so as to cause the expansion or contraction deformation of the expansion member, thereby realizing the output of power and motion forms.

The first embodiment,

Referring to fig. 1 to 4, the present invention provides a gripping apparatus, which mainly comprises a soft robot 100, a control system 200 and a processing system 300.

The soft mechanical arm 100 comprises a plurality of soft drivers A and a plurality of rigid connecting pieces 30, wherein the rigid connecting pieces 30 are connected through the soft drivers A, and the rigid connecting pieces 30 can play a role in restraining the soft drivers A. As has been described above, the soft actuator a is provided in a structure that is retractable by changing its internal pressure by a driving force, and the soft robot arm 100 controls its posture by the extension and retraction of the soft actuator a.

The control system 200 is connected to each of the plurality of soft drivers a in the soft robot arm 100, and applies a driving force to the soft drivers a. In this embodiment, the control system 200 includes a lower computer 210 and a bottom layer driving system 220, the lower computer 210 is a development board with a control chip and an operable I/0 port, and may include, but is not limited to, an STM32 single chip microcomputer, an AVR single chip microcomputer, an Arduino, and the like, and a control program thereof may be written and burned through a control program code compiling software platform in the processing system 300. The bottom layer driving system 220 comprises a micro air pump, an electromagnetic valve, an optical coupling isolation control board (or a relay and the like), and the like, wherein the lower computer 210 controls the access condition of the optical coupling isolation control board through an output signal, and further controls the switching condition of the micro air pump and the electromagnetic valve, wherein the micro air pump is used as an air source of the bottom layer driving system 220, and the electromagnetic valve is used as a channel switch of the bottom layer driving system 220, so that the air charging and sucking strategy control of each software driver A is realized. In other embodiments, the driving force can be applied to the soft driver a in other driving manners.

The processing system 300 is communicatively connected to the control system 200, for example, the upper computer 310 is used as the processing system 300, the upper computer 310 may include but is not limited to a notebook computer, a desktop computer, a mini computer (such as Raspberry Pi/Banana Pi), and the like, the upper computer 310 may interact with a user through a human-computer interaction device (such as a display, a keyboard, a mouse, and a gesture recognition device, and the like, in other words, the user may input an instruction, a control command, or data information to the upper computer 310 through the human-computer interaction device, and send the instruction, the control command, or the data information to the lower computer 210 through a communication interface after being analyzed by the upper computer 310, and the lower computer 210 controls the bottom layer driving system 220 to control the corresponding software driver a to extend and retract, in addition, the lower computer 210 may also transmit information to the upper computer 310 through the communication interface, thereby implementing bidirectional communication between the upper computer 310 and the lower computer 210.

The end of the presently most widely used soft robotic arm 100 is basically equipped with actuators for handling in each particular structured application, such as the assembly of jaws for grasping objects and the like. In particular, the actuator is responsible for implementing specific operations, and the soft mechanical arm 100 is responsible for controlling attitude motion, adjustment and the like. In the grabbing operation, generally, after the grabbing operation is completed by the actuator each time, the object to be grabbed needs to be moved and conveyed by the movement of the soft mechanical arm 100, so that the next grabbing operation can be performed. The end of the soft robot arm 100 of this embodiment may also be equipped with existing actuators, and the attitude motion and adjustment will be described in detail below.

In this embodiment, in the adjustment of the posture movement of the soft robot 100, the upper computer 310 first obtains first posture information describing a target posture of the soft robot 100. The spatial position of the midpoint of the plane at the end of the soft robot 100 may represent the spatial attitude of the soft robot 100, the end of the soft robot 100 is a grasping end for grasping the external target object 400, the other end is a fixed end connected to a base (not shown), and the user may input the target length L1 of the soft robot 100, the target inclination angle α 1 of the grasping end of the soft robot 100 relative to the fixed end, and the target rotation angle β 1 of the grasping end of the soft robot 100 relative to the fixed end as the first attitude information to the upper computer 310 through the human-computer interaction device. Of course, the first pose information includes, but is not limited to, the above parameters.

The upper computer 310 stores a motion mode equation in advance, and the motion mode equation is used for calculating and obtaining a target pressure value in the soft driver A according to the first attitude information.

After obtaining the target pressure value, the control system 200 changes the driving force acting on the soft actuator a according to the target pressure value to control the expansion and contraction of the soft actuator a, thereby realizing the purpose that the target posture input into the upper computer 310 is converted into the target pressure value which can be identified by the lower computer 210 and used for the bottom layer driving system 220 to execute the driving strategy and output.

In this embodiment, the soft drivers a are equipped with a pressure sensor and a displacement sensor, the pressure sensor is an air pressure sensor, and the displacement sensor is a flexible displacement sensor (such as a hydrogel displacement sensor, etc.), the flexible displacement sensor has the advantages of being capable of relying on self-flexibility, can be attached to the soft driver A to detect the curve length state, the accuracy is higher, the pressure sensor can detect the pressure inside the soft driver A and transmit the actual pressure value to the control system 200, the displacement sensor can also transmit the length value to the control system 200, the two types of sensors form a sensor network, the control system 200 obtains the parameter information about the software driver A, in other embodiments, the sensors on the soft driver a may include, but are not limited to, the two sensors, and the parameter information may also include parameters other than the pressure value and the length value.

After the sensor sends the parameter information to the control system 200, the control system 200 sends the parameter information to the processing system 300, that is, the upper computer 310, through the communication interface. The upper computer 310 is preset with a posture calculation model equation, the posture calculation model equation is used for obtaining second posture information for representing the current posture of the soft mechanical arm 100 according to the parameter information, the second posture information can be fed back in real time and displayed in an external display device, for example, the actual length L2 of the soft mechanical arm 100, the actual inclination angle α 2 of the grabbing end of the soft mechanical arm 100 relative to the fixed end, and the actual rotation angle β 2 of the grabbing end of the soft mechanical arm 100 relative to the fixed end can be obtained through the actual pressure value and length of the soft driver a.

The processing system 300 can compare the first posture information with the second posture information to obtain a first comparison result, and then adjust the driving force acting on the soft driver a according to the first comparison result and a pre-designed dynamic control algorithm to realize further control of the posture, thereby forming an overall large closed-loop control.

The beneficial effect in the above-mentioned process lies in:

firstly, a sensor network built by an air pressure sensor and a flexible displacement sensor can monitor and feed back data sets of internal pressure values and lengths of the soft drivers A in real time, so that the overall posture information of the soft mechanical arm 100 is synthesized, and the body sensing of the soft mechanical arm 100 is realized.

Secondly, through the motion model equation and the attitude calculation model equation, a positive-negative solution between the target attitude input by the upper computer 310 and the target pressure value of each soft driver A required to be driven by the lower computer 210 is realized, and possibilities are provided for real-time display and interaction of the upper computer 310, real-time control of the lower computer 210 and the like.

Thirdly, the difference between the current state and the target posture can be guided in real time through the first comparison result of the first posture information and the second posture information, and then the driving strategy of the bottom layer driving system 220 is guided, so that more accurate control can be performed.

Fourthly, the upper computer 310 can display and interact the attitude information of the soft mechanical arm 100 in real time, and the lower computer 210 can monitor and drive the quick response and robustness among the soft drivers A in real time.

In some embodiments, the attitude information and the pressure value in the soft body driver a can be converted by:

assuming that the inclination angle of the link unit B of a certain layer is alpha, the rotation angle is beta, and the length is l _m (length of center point of link unit B of the layer from reference center), when no foreign object is capturedWhen the load is 0, the following formula is provided:

wherein:

l ₀ for the initial original length (the length of the center point of the link unit B of the layer from the reference center when the link unit B is in the initial posture), the cross-sectional area of the inner cavity of the used soft driver A (comprising the axial driver 10 and the circumferential driver 20) is A in the formula, the elastic coefficient of the used soft driver A (comprising the axial driver 10 and the circumferential driver 20) is k in the formula, and the installation angle (X axis from the reference coordinate system) of the ith soft driver A

The length of the ith software driver A is l _i The internal pressure value of the ith software driver A is P _i And has the following:

the root of the single-layer link unit B is regarded as a reference coordinate, the end plane of the single-layer link unit B is regarded as an end coordinate after movement, namely, a certain correlation exists between an end coordinate system and a reference coordinate system, and the correlation is related to alpha, beta and l _m And (4) associating.

According to the Rodrigue's formula, the rotation matrix before and after the coordinate transformation is:

therefore, the variation matrix between the terminal coordinate system and the reference coordinate system of the root can be regarded as:

wherein the rotation matrix is:

the translation matrix is:

from this, we can calculate the coordinate variation matrix relationship between the tail end of the whole soft robot 100 having multiple link units B and the root (i.e. the head end or the fixed end) of the soft robot 100 by stacking.

In some embodiments, after obtaining the actual pressure value, the target pressure value and the actual pressure value may be compared to obtain a second comparison result, and the driving force acting on each soft body driver a is comprehensively adjusted according to the first comparison result, the second comparison result and a pre-designed dynamic control algorithm. It should be noted that, in the software robot, the device has flexibility, and can make flexible adaptation to external interference, so that the overall attitude information comparison is emphasized under normal conditions. For example, when the tip attitude of the soft mechanical arm 100 reaches the target attitude position, the body is disturbed by an external force to change the pressure or the length, and the soft mechanical arm 100 will adapt to the force disturbance due to the flexibility, but as long as α 2, β 2, and L2 of the tip attitude still match α 1, β 1, and L1 of the target attitude. When fine control adjustment or local control is required, the second comparison result between the current pressure value and the target pressure value in the controlled area can be more adopted as a main guiding strategy.

By constructing a sensor network and comprehensively referring to the first comparison result and the second comparison result, when the bottom layer driving system 220 drives the air pressure of the plurality of soft drivers A, the air pressure closed-loop control and the displacement closed-loop control formed by the air pressure sensors and the flexible displacement sensors are provided, and the double closed-loop control arrangement improves the control accuracy, so that the driving strategy of the bottom layer driving system 220 in the next step is jointly made under the guidance of a dynamic control algorithm.

Example two:

the soft robotic arm 100 of the first embodiment can use the existing actuators to grasp the target object 400, such as the gripping jaws installed on the grasping end, while in other embodiments of the present invention, based on the soft robotic arm 100, the soft actuator a is designed to follow the physiological configuration and movement of the animal, wherein the soft actuator a is divided into a circumferential actuator 20 and an axial actuator 10, as shown in fig. 2 to 4. Constructing a link unit B by using a circumferential driver 20 and a rigid connecting piece 30, and connecting two adjacent link units B by using an axial driver 10; on one hand, by utilizing the structure and the motion characteristics of radial expansion and contraction of the link units B, axial expansion and contraction of the adjacent link units B and integral rotary bending, swallowing actions of the link animals in the predation process can be coupled and simulated, and series of operations such as grabbing, transferring and conveying of the target object 400 are realized, so that the grabbing function of the clamping jaws and the original transferring and conveying function of the soft mechanical arm 100 are integrated, and the efficiency of series processes such as grabbing, conveying, post-processing and the like can be improved; under the coordination driving action of the bottom layer driving system 220, the rigidity of the soft mechanical arm 100 and the capability of the target object 400 can be ensured, the self shape can be shaped in a self-adaptive manner according to the structural form of the target object, and the power output effect with multiple degrees of freedom and high flexibility is realized; on the other hand, by adopting the modular structure design, the combination and the construction of the whole structure of the software mechanical arm 100 can be rapidly and self-definitively carried out, so that the software mechanical arm can better respond or adapt to different application scenes and different application requirements, and high universality is realized. This will be described in further detail below.

The main body of the soft mechanical arm 100 is a tubular structure constructed by progressively stacking a plurality of axial drivers 10 and at least N layers (N is greater than or equal to 2) of link units B. It should be noted that, since the main body of the soft mechanical arm 100 is tubular, the spatial orientation in the axial direction, radial direction, circumferential direction, etc. can be naturally formed or defined by using the main body as a reference, so as to create conditions for clearly describing the components.

Referring to fig. 2 to 4, the link unit B is an annular structure mainly composed of a plurality of circumferential drivers 20 and at least three rigid connectors 30; wherein, at least three rigid connectors 30 are arranged at intervals along the circumferential direction, and a circumferential driver 20 is arranged between every two adjacent rigid connectors 30, that is, in the same link unit B, the circumferential drivers 20 and the rigid connectors 30 are arranged and distributed in an annular array in an interval staggered manner; the rigid connecting piece 30 can be formed by processing metal materials or injection molding or assembling plastic materials; the two ends of the circumferential driver 20 are fixedly connected to the corresponding rigid connecting members 30, so that the rigid connecting members 30 are used for constraining the circumferential driver 20 from the two outer ends of the circumferential driver, when the circumferential driver 20 deforms and expands, the expansion and contraction direction of the circumferential driver conforms to the external constraint form (namely the arrangement form of the rigid connecting members 30), and a motion form of which the expansion and contraction direction is dominated by the rigid connecting members 30 is formed; at least three rigid connectors 30 can form bayonets 40 for grabbing the target object 400 in the circumferential direction, so that when the circumferential driver 20 contracts and deforms, two adjacent rigid connectors 30 can be driven to mutually approach in the circumferential direction, the overall radial gathering contraction of the link unit B is further realized, and the bayonets 40 of the corresponding link unit B are reduced; when the circumferential driver 20 is deformed, the two adjacent rigid connectors 30 can be driven to move away from each other in the circumferential direction, so that the overall radial expansion and expansion of the link unit B can be realized, and the bayonet 40 of the corresponding link unit B is expanded.

The number of the link units B can be determined according to the length requirement of the whole soft mechanical arm 100 in practical application, and N layers of the link units B are distributed at intervals along the axial direction, so that the rigid connecting piece 30 of one link unit B can be in one-to-one correspondence with the rigid connecting piece 30 of another link unit B along the axial direction, namely: in the overall structure of the soft mechanical arm 100, the rigid connecting members 30 in the same link unit B are arranged at intervals along the circumferential direction, and the rigid connecting members 30 in different link units B are arranged at intervals along the axial direction. The axial driver 10 is arranged between every two adjacent link units B and is used for axially connecting the two adjacent link units B, so that the whole body of the soft mechanical arm 100 is similar to a screen mesh type tubular structure, and the rigid connecting piece 30 and the link units B can be used for applying constraint to the axial driver 10 from two outer ends of the axial driver 10, so that the stretching direction of the axial driver 10 can be compliant with the constraint form of the outer part of the axial driver when the deformation and stretching effect occurs; through independent synchronous control or non-differential control of each axial driver 10, the same deformation quantity can be generated when the axial drivers 10 extend or contract, so that the whole soft mechanical arm 100 can axially linearly contract under the condition that the link units B are driven to mutually approach along the axial direction, and the whole soft mechanical arm 100 can axially linearly extend under the condition that the link units B are mutually far away along the axial direction; by differential control or independent control of the axial drivers 10, different deformation amounts can be generated when the axial drivers 10 extend or contract, so that the whole soft mechanical arm 100 can be caused to deflect and bend towards a certain direction, and the soft mechanical arm 100 can be caused to pitch and bend or roll in the circumferential direction.

Based on this, the flexible deformation effect generated by the circumferential driver 20 can enable the whole soft mechanical arm 100 to output the movement of expanding and contracting in the radial direction section by section, and the intuitive expression effect is that the diameter of the link unit B is expanded or reduced, and the bayonet 40 of the link unit B is also expanded or reduced; meanwhile, the flexible deformation effect generated by the axial driver 10 can be utilized to enable the whole soft mechanical arm 100 to output axial linear stretching, pitching bending, circumferential rolling and other motions, and the visual performance effect is that the whole soft mechanical arm 100 performs spatial motion in various forms such as a cylinder shape, a cone shape and the like, so that the swallowing action of the link animal in the predation process can be simulated, and series of operations such as grabbing, transferring and conveying, primary post-processing and the like of the target object 400 are realized, and the following brief summary of grabbing the swallowing target object 400 by the soft mechanical arm 100 is as follows: when the target object 400 is grabbed, the radial size of the link unit B at the tail end of the soft mechanical arm 100 can be controlled to be enlarged, and the radial sizes of other link units B are contracted to be minimum, so that the state that the mouth of the link animal is opened to prepare for predation is simulated. The target object 400 enters the body of the soft mechanical arm 100 through the link unit B at the tail end to simulate the state that the target object 400 enters the mouth of the link animal, and then the link unit B at the tail end and the associated axial driver 10 can be controlled to gradually contract, and the link unit B at the subsequent level and the associated axial driver 10 are controlled to gradually expand or extend, so that the target object 400 is gradually transferred and conveyed until the target object enters the head end (namely the fixed end) of the soft mechanical arm 100, and the action of swallowing food by the link animal is completely simulated.

When the link unit B of the soft mechanical arm 100 shrinks the bayonet 40, the rigid connector 30 directly contacts the target object 400 to grasp the target object 400, and when the link unit B directly contacts the target object 400, the circumferential driver 20 in the link unit B and the axial driver 10 connected with the link unit B generate an interaction force with the grasped target object 400 (via the rigid connector 30). The soft driver A changes its internal pressure to directly generate its own displacement change when not contacting the object, and the contact object changes its internal pressure to generate no own displacement change and generate an interaction force on the contact object. Under the same pressure variation, the soft driver A has direct correlation between the displacement output to the outside without contacting the object and the magnitude of the acting force output to the object without displacement in the rigid connecting piece 30 connected with the soft driver A, namely, the pressure, the displacement, the acting force magnitude and the self characteristics of the soft driver A have direct correlation, a load appearance calculation model and a load acting force calculation model can be established according to the principle, after the pressure value and the length in the given soft driver A are obtained, whether the target object 400 is grabbed or not can be judged firstly, the acting force between the link unit B and the target object 400 and the appearance characteristics of the target object 400 can be further obtained by calculation, and it is easy to understand that the appearance characteristics of the target object 400 are closer to the real appearance contour of the target object 400 as the number of the rigid connecting pieces 30 in the link unit B is larger, the obtained appearance characteristics of the target object 400 and the acting force between the target object 400 and the object 400 when the target object 400 is grabbed can be further transmitted to the upper computer 310 for real-time display and interaction.

The above-mentioned software robot arm 100 is favorable to the following to the grabbing and grabbing control mode of the target object 400:

(1) after one target object 400 is grabbed and transported into the soft mechanical arm 100, the released link unit B and the associated axial driver 10 can continuously grab and transport the next target object 400, thereby realizing continuous grabbing and transporting operations of the target object 400, and enabling the soft mechanical arm 100 to have high-efficiency operation performance.

(2) The method realizes the calculation of the load information such as the appearance of the target object 400 and the mutual acting force thereof in the interaction with the target object 400 (such as grabbing and swallowing transmission), realizes the body perception, and has the perception capability for the grabbed object.

In some embodiments, in each link unit B, every two adjacent circumferential actuators 20 are connected in series by a fluid line (not shown), so that the circumferential actuators 20 in one link unit B form a complete continuous fluid medium flow channel, and at least one of the fluid lines is preferably used to connect with the bottom layer driving system 220, so as to perform the undifferentiated driving control on the N second soft bellows 21 in the same link unit B, that is: the at least two second soft telescopic parts 21 are in an isobaric state and perform self telescopic motion in a circular or regular form, so that a radial expansion and contraction motion effect of the link unit B is formed; in specific implementation, the circumferential drivers 20 in each link unit B are controlled indifferently, and the axial drivers 10 between two adjacent link units B are controlled differentially and independently, so that the above-mentioned various motions or postures can be coupled and simulated, the complexity of controlling the motion form of the soft mechanical arm 100 can be reduced, and the operability of the soft mechanical arm 100 can be improved. In this embodiment, the fluid lines may be arranged within the rigid links 30 to optimize the overall structural configuration of the entire link unit B.

In other embodiments, each circumferential actuator 20 may be independently driven and controlled without considering the complexity of the control system 200 or method of the soft robotic arm 100, so that a link unit B can perform radial expansion and contraction movements in a non-circular or irregular shape to adaptively conform to the structural shape of the target object 400, thereby continuously grasping target objects 400 with different shapes.

In some embodiments, each side of the rigid connection member 30 may be divided to have an axial end surface d corresponding to the axial driver 10, a circumferential end surface e corresponding to the circumferential driver 20, and an inner ring end surface f located on the inner ring side of the link unit B; the axial end face d may be provided with a recessed structure of a certain depth so as to be capable of connecting the axial driver 10 in a manner of splicing adhesion or the like, the circumferential end face e may also be provided with a recessed structure of a certain depth so as to be capable of connecting the circumferential driver 20 in a manner of splicing adhesion or the like, and the inner ring end face f is mainly used for contacting with the surface of the target object 400, so as to use the inner ring end face f as a contact point with the target object 400 when the link unit B is radially contracted, thereby realizing the grabbing operation of the target object 400. In other embodiments, the rigid connection member 30 may have other shapes, such as a curved square structure, a spherical structure, etc., according to the requirements of the specific application.

In some embodiments, referring to fig. 5 to 7, the rigid connection member 30 is mainly assembled and combined by three types of components, namely a base member 31, a seat plate member 32, and a touch pressing member 33; wherein, the base member 31 is mainly of a "U" -like structure, that is: the base member 31 has two base portions 31-1 arranged at intervals in a layer-wise manner in the axial direction and a linking arm portion 31-2 arranged in the axial direction to link the two base portions 31-1 together; the seat plate members 32 are two in total, the seat plate member 31 is clamped between the two base parts 31-1 and located at two sides of the linkage part 31-2, namely, the seat plate member 32 is used for covering the base member 31 at two side opening structures located in the circumferential direction of the linkage part 31-2, the axial end face d is formed on the base part 31-1, and the circumferential end face e is formed on the seat plate member 32; the touching and pressing member 33 is clamped between the two base parts 31-1 and is arranged side by side with the connecting arm part 31-2 at intervals, namely, the touching and pressing member 33 is used for carrying out port sealing on a structural component with a port, which is composed of the base part 31 and the seat plate part 32, and the inner ring end face f is formed on the touching and pressing member 33.

So, utilize base member 31, bedplate spare 32 and touch and press piece 33 to assemble and constitute a cavity cubic structure, promptly: the rigid connecting piece 30 is a hollow cube structure; on one hand, the hollow structure of the rigid connection member 30 can create advantages for effectively reducing the load of the soft mechanical arm 100 or the quality of the soft mechanical arm 100, and can provide sufficient structural space for assembling the components such as the fluid pipeline and the information detection member; on the other hand, the characteristics of the rigid connection member 30 in a detachable combination are utilized to facilitate quick detachment and maintenance of the axial driver 10, the circumferential driver 20 and the associated components thereof.

In other embodiments, the spatial orientation of the base member 31 may be changed so that the base portion 31-1 is located in the circumferential direction of the link unit B, and the circumferential driver 20 is connected by the base portion 31-1 and the axial driver 10 is connected by the seat member 32. Of course, the contact pressing member 33 may be configured to be similar to a U-shaped structure, and the base member 31 may be configured to be a single-plate structure, so that the rigid connection member 30 with another structure can be assembled and combined to meet different assembly and use requirements.

In some embodiments, referring to fig. 5 to 7, a first locking member 32-1 is disposed at one end of the seat member 32 adjacent to the linking arm portion 31-2, and a second locking member 31-3 is disposed at the linking arm portion 31-2 and the seat portion 31-2; the first fastener 32-1 is a groove structure distributed along the end profile of the seat plate 32 and having a U-like extending track, fastening positions are provided at both ends of the first fastener 32-1, and the second fastener 31-3 includes a convex strip portion provided on the linking arm portion 31-2 and inserted into the groove of the first fastener 32-1 in an aligned manner and a barb portion provided on the base portion 31-2 and fastened in the fastening position of the first fastener 32-1 in an aligned manner, so that the seat plate 32 and the base member 31 can be stably assembled and combined by utilizing the aligned matching connection relationship between the first fastener 32-1 and the second fastener 31-3. Based on the same structure or function principle, a third buckling piece 33-1 is arranged at the end part of the touch pressing piece 33 adjacent to the base part 31-1, and a fourth buckling piece 31-4 is arranged on the base part 31-1; the fourth locking member 31-4 is a groove structure disposed at one end of the base portion 31-1 adjacent to the touching member 33 and having an extending track similar to an "L" shape, and the first locking member 31-4 is located at a symmetrical side of the base portion 31-1, the third locking member 33-1 is a structure similar to an elastic arm formed by extending the touching member 33, when the touching member 33 is pushed toward the direction of the connecting arm portion 31-2, the third locking member 33-1 can be engaged in the fourth locking member 31-4 in an aligned manner, so that the touching member 33 can be firmly assembled on the base member 31 by utilizing the aligned and matched connection relationship between the third locking member 33-1 and the fourth locking member 31-4.

In other embodiments, each alignment-matching fastener can also be structurally designed with reference to the existing fastener connection structure, and the key points are as follows: the quick assembly and disassembly combination among the base member 31, the seat plate member 32 and the contact member 33 can be realized.

In some embodiments, referring to fig. 5 to 7, the pressing member 33 is mainly composed of two parts, namely, an end cap part 33-2 and a non-slip part 33-3; the end cover part 33-2 is used as a bearing carrier of the antiskid part 33-3, is clamped between the two base parts 31-1 and is distributed with the linking arm part 31-2 at intervals side by side, the antiskid part 33-3 is superposed and fixed on the surface of the end cover part 33-2 on the side far away from the linking arm part 31-2, and the inner ring end face f is formed on the antiskid part 33-3. The main body part of the rigid connecting piece 30 with a hollow structure is formed by the structural combination relationship between the end cover part 33-2, the seat plate part 32 and the base part 31, and the antiskid part 33-3 is used as a contact part of the rigid connecting piece 30 and the target object 400, so that the contact area can be increased and larger friction force can be generated when the target object 400 is grabbed and swallowed, the phenomena of sideslip and the like of the target object 400 can be prevented, the flexible contact effect with the target object 400 can be realized, and unnecessary damage to the surface of the target object 400 can be avoided. In this embodiment, the anti-slip part 33-3 is integrally injection molded from a flexible material such as silicone, specifically, a recessed structure may be provided on the surface of the end cap part 33-2, and after the molten material of the anti-slip part 33-3 is injected into the recessed structure of the end cap part 33-2 and solidified by using the end cap part 33-2 as a female mold (or bottom mold) in the injection molding of the anti-slip part 33-3, the structural form in which the anti-slip part 33-3 is embedded in the end cap part 33-2 may be naturally formed, thereby ensuring the structural strength and stability of the entire contact pressing member 33.

Example three:

on the basis of the grasping apparatus disclosed in the second embodiment, the present embodiment discloses a control method of the grasping apparatus.

In this embodiment, before controlling the soft robot 100, the working mode of the soft robot 100 is selected, wherein the working mode of the soft robot 100 includes, but is not limited to, a spatial movement mode, a swallowing gripping mode, and a manual manipulation mode. The spatial motion mode is used to control the motion and attitude of the robot 100 in space so that the end of the robot 100 approaches the target object 400 or moves to a predetermined position, and the manual manipulation mode is used to give the user control of the robot 100 to manual operation. The aforementioned spatial movement mode and manual manipulation mode can also be applied to the grasping apparatus disclosed in the first embodiment. In the swallowing grasping mode, the soft robotic arm 100 will automatically begin to grasp and swallow the target object 400. Specifically, the technician or operator may select and operate the mode through the interactive interface of the upper computer 310.

Generally, the application of the three modes of the soft robot 100 can be as follows: the method comprises the steps of firstly entering a spatial motion mode to control the soft mechanical arm 100 to approach the target object 400 and/or adjust to a proper spatial posture, and then entering a swallowing and grabbing mode to grab the target object 400, wherein the process can be switched to a manual operation mode according to requirements. The control method in the three operation modes will be described one by one.

Fig. 8 is a flowchart of a control method in the spatial motion mode, which includes the steps of:

step 1-1, first posture information for describing a target posture of the soft mechanical arm 100 is acquired.

The spatial position of the midpoint of the plane at the end of the soft robot 100 may represent the spatial attitude of the soft robot 100, while the end of the soft robot 100 is a grasping end for grasping the external target object 400, and the other end is a fixed end connected to a base (not shown), and the user may use the target length L1 of the soft robot 100, the target inclination angle α 1 of the grasping end of the soft robot 100 relative to the fixed end, and the target rotation angle β 1 of the grasping end of the soft robot 100 relative to the fixed end as the first attitude information through the human-computer interaction device. Of course, the first pose information includes, but is not limited to, the parameters described above.

And step 1-2, obtaining a target pressure value in the soft body driver A according to the first attitude information.

Through a pre-designed motion mode equation, a target pressure value in the soft driver A can be obtained through calculation from the first attitude information.

And 1-3, changing the driving force acting on the soft actuator A according to the target pressure value so as to control the expansion and contraction of the soft actuator A.

The driving force acting on the soft driver A is changed by changing the flow rate of the fluid medium in the soft driver A, and the expansion and contraction of the soft driver A can be controlled by inflating and inhaling air in the embodiment. Moreover, if the amount of expansion and contraction of the axial drivers 10 between adjacent link units B is changed synchronously, it is visually represented that the robot arm 100 is extended or shortened, and if the amount of expansion and contraction of the axial drivers 10 between adjacent link units B is changed asynchronously, it is visually represented that the robot arm 100 is turned or bent.

Step 1-4, acquiring parameter information of the soft driver A, wherein the parameter information at least comprises the length of the soft driver A and the actual pressure value inside the soft driver A.

The actual pressure value inside the soft driver A can be obtained through the detection of a pressure sensor inside the soft driver A, and the length of the soft driver A can be obtained through the detection of a flexible displacement sensor. In other embodiments, the sensors on the soft driver a may include, but are not limited to, the two sensors, and the parameter information may also include parameters other than the pressure value and the length value.

And 1-5, obtaining second posture information for representing the current posture of the soft mechanical arm 100 according to the parameter information.

The second attitude information can be solved from the parameter information according to the pre-designed attitude solution model equation, for example, the actual length L2 of the soft body manipulator 100, the actual inclination angle α 2 of the grabbing end of the soft body manipulator 100 relative to the fixed end, and the actual rotation angle β 2 of the grabbing end of the soft body manipulator 100 relative to the fixed end can be obtained through the actual pressure value and length of the soft body actuator a.

And 1-6, comparing the first attitude information with the second attitude information to obtain a first comparison result. The first comparison result represents the difference between the current pose and the target pose.

Step 1-7, adjusting the driving force applied to the soft driver A at least according to the first comparison result.

The first comparison result can be used as the input of a pre-designed dynamic control algorithm to adjust the pressure inside each soft driver A, thereby forming the overall large closed-loop control.

The following soft robot 100 has N (N is an integer of 2 or more) layers of link units B at the end (gripping end) of the soft robot 100, and the soft robot 100 also has N-1 layers of axial units C each including axial drivers 10 distributed along the circumferential direction of the soft robot 100. Fig. 9 is a flowchart of a control method in the swallowing grabbing mode, which includes the steps of:

and 2-1, controlling the nth link unit B to execute the operation of grabbing the target object 400.

Specifically, the operation of grasping the target object 400 may include the steps of:

and 2-1-1, controlling the nth link unit B to expand the bayonet 40. This step is used to simulate the mouth opening movement of the animal in the animal feeding process.

And step 2-1-2, controlling the link unit B of the (N-1) th layer to reduce the bayonet 40. This step can further increase the angle of the link unit B at the end of the soft robot arm 100, which is beneficial for grasping larger-sized objects.

And 2-1-3, controlling the axial unit C of the (N-1) th layer to extend. This step simulates the head extension movement of the link animal during predation, brings the end of the soft robotic arm 100 closer to the target object 400, and provides sufficient axial expansion and contraction space for swallowing and transporting the target object 400 from the nth link unit B to the N-1 th link unit B. Of course, the axial cells C elongation of other layers may also be controlled.

And 2-1-4, controlling the nth link unit B to reduce the bayonet 40. This step allows the end link unit B of the soft robot arm 100 to retract closed and directly grasp the target object 400, mimicking the biting motion of the link animal during predation.

And 2-2, judging whether the target object 400 is grabbed by the nth link unit B. If the target object 400 is not grabbed, the step 2-1 is continued, and if the target object 400 is grabbed, the step 2-3 is performed.

In this step, it can be determined whether the target object 400 is grabbed by the nth layer link unit B according to the load shape calculation model and the load acting force calculation model of the second embodiment, and the obtained pressure value and length in the soft driver a.

Step 2-3, let the variable X be N, and define the input M in step 2-4 as X.

And 2-4, controlling the Mth layer link unit B to execute a single-layer transmission step. The single layer transfer step is used to transfer the target object 400 from the mth layer link unit B to the M-1 layer link unit B. In this step, the user may also input a value of M for the positioning of the target object 400 by the program.

And 2-5, judging whether X is greater than 2, if so, executing the step 2-6, and if not, executing the step 2-7.

If X is greater than 2, it represents an incomplete complete swallowing delivery procedure. In step 2-5, in order to deliver the target object 400 to the link unit B of layer 1, X is compared with 2, and in other embodiments, the target object 400 may be delivered to the link unit B of a specific layer.

And 2-6, inputting the variable X-1 and inputting the variable M-X, and executing the step 2-4 again.

And 2-7, controlling the link unit B of the X-1 layer to clamp the target object 400, and recovering the original length of other link units B and the axial unit C. In this step, that is, the layer 1 link unit B shrinks the bayonet 40 to clamp the target object 400.

In some embodiments, the upper end of the level 1 link element B of the soft robotic arm 100 may be equipped with a collection device or receptacle for collecting objects that are grasped and finished with swallowing transport.

In some embodiments, in practical operation, the link unit B and the axial unit C with 2 to N-1 layers in the soft mechanical arm 100 may be equipped with simple post-processing tools for the grasped object, so as to realize the capability of performing simple post-processing operations, such as surface impurity removal, spraying, and the like, on the grasped object during the grasping, swallowing, and conveying processes. The specific assembly tool depends on the post-processing required in the actual operating requirements.

In some embodiments, as shown in fig. 10, the single layer transfer step may include:

and 3-1, expanding the bayonet 40 by the M-1 layer link unit B. In the step, the bayonet 40 of the link unit B of the layer M-1 is expanded to enlarge the clamping range so as to prepare for the next step of shrinking and clamping the target object 400, and in addition, the link unit B of the layer M can be controlled to shrink the bayonet 40 so as to ensure that the link unit B of the layer M shrinks and clamps the target object 400 to prevent the target object from falling.

And 3-2, controlling the M-1 layer of axial units C to shrink so as to enable the M-1 layer of link units B clamping the target object 400 to be close to the M-1 layer of link units B. This step allows the upper portion of the target object 400 (the end away from the robot arm 100 being the upper portion) to enter the bayonet 40 of the layer M-1 link unit B in preparation for the next shrinking to grip the target object 400.

And 3-3, controlling the M-1 th layer link unit B to reduce the bayonet 40 to clamp the object, and respectively clamping the lower part and the upper part of the target object 400 by the M-1 th layer link unit B and the M-1 th layer link unit B at the moment. In this step, whether the target object 400 is grabbed by the M-1 layer link unit B can be judged according to the load appearance calculation model, the load acting force calculation model, the acquired pressure value and the acquired length in the soft driver A.

And 3-4, controlling the M-th layer link unit B to expand the bayonet 40, so that the M-th layer link unit B loosens the lower part of the target object 400.

And 3-5, judging whether the M-1 th link unit B clamps the preset position of the target object 400, if not, continuing to execute the step 3-6, and if so, executing the step 3-8.

For example, after the step 3-1-4, the axial unit C on the M-1 th layer is extended to the original half length, and then the link unit B on the M th layer is controlled to reduce the bayonet 40, if the target object 400 can be clamped, most of the lower part of the target object 400 is still not clamped by the link unit B on the M-1 th layer, that is, the single-layer grabbing and transferring step is not completed. It should be noted that the length of the elongated axial unit C of the M-1 th layer in this step is optional, and may be, for example, three quarters of the original length.

And 3-6, controlling the Mth layer link unit B to grab the target object 400 again.

In this step, after the M-1 th layer of axial drivers 10 are further controlled to extend, the M-th layer of link units B are controlled to shrink the bayonets 40 to clamp the target object 400.

And 3-7, controlling the M-1 st layer link unit B to expand the bayonet 40, enabling the M-1 st layer link unit B to loosen the target object 400, and continuing to execute the step 3-2.

And 3-8, controlling the M-th layer link unit B and the M-1-th layer axial unit C to reset.

The embodiment realizes the positive and negative solution between the target attitude and the target pressure value of each software driver needing to be driven, and provides possibility for real-time display and interaction of attitude information, real-time control of the software drivers and the like; the data collected by the sensor network not only can realize body perception, but also can perceive the grabbed target object; the closed-loop control is realized for the software driver, and the control is more accurate; the soft mechanical arm can grab external objects and can realize continuous grabbing and swallowing of a plurality of objects with different shapes.

Those skilled in the art will appreciate that all or part of the functions of the methods in the above embodiments may be implemented by hardware, or may be implemented by a computer program. When all or part of the functions of the above embodiments are implemented by a computer program, the program may be stored in a computer-readable storage medium, and the storage medium may include: a read only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, etc., and the program is executed by a computer to realize the above functions. For example, the program may be stored in a memory of the device, and when the program in the memory is executed by the processor, all or part of the functions described above may be implemented. In addition, when all or part of the functions in the above embodiments are implemented by a computer program, the program may be stored in a storage medium such as a server, another computer, a magnetic disk, an optical disk, a flash disk, or a removable hard disk, and may be downloaded or copied to a memory of a local device, or may be version-updated in a system of the local device, and when the program in the memory is executed by a processor, all or part of the functions in the above embodiments may be implemented.

The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.

Claims

1. The control method of the soft mechanical arm is characterized in that the soft mechanical arm comprises a plurality of soft drivers and a plurality of rigid connecting pieces, the rigid connecting pieces are connected through the soft drivers, the soft drivers are arranged in a telescopic structure which can change the internal pressure through the driving force, and the posture of the soft mechanical arm is controlled through the stretching of the soft drivers; the soft driver comprises an axial driver and a circumferential driver; the soft mechanical arm comprises N layers of link units distributed along an axial hierarchy, wherein N is more than or equal to 2, each link unit comprises at least three rigid connecting pieces used for forming a bayonet, adjacent rigid connecting pieces in each link unit are connected through a circumferential driver and are driven by the circumferential driver to approach or separate from each other so that the bayonet is expanded or reduced, adjacent link units are connected through an axial driving piece and are driven by the axial driver to approach or separate from each other, and the nth layer of link unit is used for grabbing a target object outside the soft mechanical arm through the reduced bayonet;

the control method comprises the following steps:

obtaining second attitude information for representing the current attitude of the soft mechanical arm according to the parameter information;

adjusting the driving force acting on the soft driver at least according to the first comparison result; and

controlling the Nth-layer link unit to execute the operation of grabbing the target object;

and judging whether the nth link unit grabs a target object or not according to the parameter information of the circumferential driver of the nth link unit, if the target object is not grabbed, controlling the nth link unit to expand a bayonet and then continue to approach the target object and reduce the bayonet, and if the target object is grabbed, starting to execute a single-layer transmission step from the nth link unit until the target object is transmitted to a link unit of a preset level, wherein the single-layer transmission step is used for transmitting the target object from the previous link unit to the next link unit.

2. The method of claim 1, wherein obtaining the parameter information of the soft-body driver further comprises:

comparing the target pressure value with the actual pressure value to obtain a second comparison result;

and comprehensively adjusting the driving force acting on each soft driver according to the first comparison result and the second comparison result.

3. The method of claim 1, wherein after capturing the target object, the method further comprises:

and obtaining the appearance characteristics of the target object and/or the acting force applied to the target object when the target object is grabbed according to the parameter information of the circumferential driver in the Nth layer link unit.

4. The method of claim 1, wherein the single layer transferring step of the target object between the previous layer link unit and the next layer link unit comprises:

controlling the next-layer link unit to execute the operation of grabbing the target object;

and controlling the previous layer of link unit to release the target object and move to a preset position, then reducing the bayonet, and judging whether the next layer of link unit grabs the preset position of the target object or not according to the parameter information of the circumferential driver of the previous layer of link unit.

5. The method of claim 4, wherein the soft robot comprises a fixed end and a grasping end for grasping the target object, and the first pose information comprises at least a target length of the soft robot, a target rotation angle of the grasping end of the soft robot relative to the fixed end, and a target tilt angle of the grasping end of the soft robot relative to the fixed end.

6. A grasping device, comprising:

the soft mechanical arm comprises a plurality of soft drivers and N layers of link units distributed along the axial direction in a hierarchical mode, the soft drivers are all arranged into a telescopic structure capable of changing the internal pressure of the soft drivers through a driving force, each soft driver comprises a circumferential driver and an axial driver, each link unit comprises at least three rigid connecting pieces used for forming bayonets, adjacent rigid connecting pieces in each link unit are connected through the circumferential drivers and are close to or far away from each other under the driving of the circumferential drivers, so that the bayonets are enlarged or reduced, adjacent link units are connected through the axial driving pieces and are close to or far away from each other under the driving of the axial drivers, and the N layer of link units are used for grabbing target objects outside the soft mechanical arm through the reduced bayonets;

a processing system communicatively coupled to the control system for controlling the soft robotic arm by the method of any one of claims 1-5.

7. The grasping device according to claim 6, wherein the soft actuator is provided with a pressure sensor and a displacement sensor, the pressure sensor is used for detecting the pressure inside the soft actuator and transmitting the pressure value to the control system, and the displacement sensor is used for detecting the length of the soft actuator and transmitting the length value to the control system.

8. The grasping device according to claim 7, wherein the displacement sensor is a flexible displacement sensor.

9. A computer-readable storage medium, characterized in that the medium has stored thereon a program which is executable by a processor to implement the method according to any one of claims 1-5.