Structural parameter optimization method of pneumatically compensated flexible actuator based on dielectric elastomer

Abstract

The present invention provides a method for optimizing the structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer, which specifically includes the following steps: S1, determining the configuration structural dimension parameters of the actuator according to the working principle of the actuator; S2, using structural parameters to express the performance expression of the pneumatically compensated flexible actuator, and establishing a mathematical model of the total mass, working voltage and material stress of the actuator; S3, simplifying each structural parameter in combination with actual working conditions and application requirements, and determining the parameter value range; S4, analyzing the sensitivity of key structural parameters in each mathematical model, and determining the target optimization function; S5, considering the rationality of the volume of the entire actuator under actual working conditions, establishing the constraint conditions for the design of the entire actuator; S6, optimizing the structural parameters, comprehensively analyzing the optimization results and making choices, and obtaining the optimal structural parameters. The present invention can realize the efficient design of the actuator structure, while avoiding the deformation problem caused by the hysteresis effect when the flexible material is started.

Description

Technical Field

[0001] The invention belongs to the field of flexible driver optimization, and in particular relates to a method for optimizing structural parameters of a pneumatically compensated flexible driver based on a dielectric elastomer. Background Art

[0002] Flexible actuators are a special type of actuator. The main features that distinguish them from rigid actuators are better smooth motion and higher error tolerance. In actual engineering and robotic applications, flexible actuators as drive units usually feature low cost and high output. Flexible actuators drive loads by deformation of materials. Compared with traditional rigid transmission parts, they have smaller structural dimensions and diverse shapes and structures. They have the advantages of high modularity and assemblability, strong adaptability, high energy density, fast response speed, and variable stiffness. The realization of the above functional advantages depends on the selection of specific functional properties of flexible materials, such as silicone, memory alloys, ion polymer metal composites, dielectric elastomer materials, hydrogels and other soft materials and their composites. Under the drive of corresponding electricity, magnetism, heat or light, the elastic-plastic deformation of the prepared materials can be achieved, thereby realizing the intended machine system function.

[0003] However, since the driving element is made of flexible material, it is nonlinear during deformation, which will affect the working performance of the driver. In addition, electrodeformable flexible materials represented by dielectric elastomer materials have a hysteresis effect during startup. Therefore, the deformation effect during rapid actuation will be inconsistent with that during normal operation, which brings difficulties to the structural design of micro-flexible drivers. Summary of the invention

[0004] The purpose of the present invention is to provide a method for optimizing the structural parameters of a pneumatically compensated flexible drive based on a dielectric elastomer. A pneumatic transmission component is introduced to compensate for the hysteresis effect of the dielectric elastomer drive during rapid startup. Based on the working principle of the flexible drive and the pneumatic compensation component, the overall structural size parameters are determined, and the performance expression of the pneumatically compensated flexible drive based on the dielectric elastomer is constructed using the structural parameters. The objective function is optimized by multiple objectives based on the optimization algorithm, the optimization results are manually analyzed and selected, and the optimal structural design parameters of the entire drive are obtained according to the comprehensive evaluation function.

[0005] The present invention provides a method for optimizing the structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer, which specifically comprises the following steps:

[0006] S1. Based on the working principle of the pneumatic compensation flexible actuator of dielectric elastomer, determine the structural dimension parameters of the actuator configuration;

[0007] S2. Taking the mass, working voltage and material stress of the dielectric elastomer drive unit as evaluation indicators, taking the mass and material stress of the air pressure compensation unit as evaluation indicators, using structural parameters to express the performance expression of the pneumatic compensation flexible actuator, and establishing a mathematical model of the total mass, working voltage and material stress of the pneumatic compensation flexible actuator;

[0008] S3. Combined with the actual working conditions and application requirements, the structural parameters in the performance expression of the pneumatic compensation flexible actuator are preliminarily simplified, and the parameter value range is determined;

[0009] S4. Analyze the sensitivity index of key structural parameters in each mathematical model. When the sensitivity index is small, it is divided into fixed parameters. When the sensitivity index is large, it is divided into parameters to be analyzed. Determine the simplified structural parameters to express the multi-objective optimization function with total mass, working voltage and material stress as the target; establish the multi-objective optimization expression as follows:

[0010] f=min(f1,f2,f3,f4) (1)

[0011] Wherein, f1 represents the total mass of the pneumatic compensation flexible actuator; f2 represents the working voltage of the pneumatic compensation flexible actuator; f3 represents the stress at the cross section of the dielectric elastomer film of the pneumatic compensation flexible actuator after longitudinal cutting; f4 represents the stress at the cross section of the pneumatic component of the pneumatic compensation flexible actuator after longitudinal cutting;

[0012] S5. Considering the rationality of the volume of the pneumatic compensation flexible actuator under actual working conditions, the constraints for the design of the pneumatic compensation flexible actuator are established according to the relationship between the working gas pressure and the structural parameters:

[0013]

[0014] Where p is the working pressure and [σ] PE is the allowable stress of the pneumatic component material; S2 is the area of ​​the material under stress; S1 is the actual area of ​​the cross section under gas pressure; e is the height of the deformation space; r2 is the radius of the gas source input cross section; a P is the height of the gas chamber in the synaptic cross section; b P is the width of the gas chamber in the synaptic cross section; δ PH is the transverse wall thickness of the synaptic gas chamber; f is the width of the transverse deformation space; c is the height of the curved trapezoid; θ is the central angle of the curved edge;

[0015] There is a constraint relationship between the thickness and side length of the packaging film material:

[0016]

[0017]

[0018] Among them, δ1 is the thickness of the dielectric elastomer; δ2 is the thickness of the flexible frame; a1 is the side length of the plane shape of the dielectric elastomer; c2 is the vertical width of the flexible frame;

[0019] S6. Utilizing the multi-objective optimization function obtained in S4 and the constraints obtained in S5, the drive structural parameters are optimized and an optimal solution set is obtained. A set of solutions is determined from the optimal solution set to obtain the optimal structural parameters of the pneumatically compensated flexible drive.

[0020] Preferably, the driver comprises a dielectric elastomer driver and a pneumatic component, wherein the pneumatic component is arranged on the dielectric elastomer driver.

[0021] Preferably, the driver comprises an upper flexible frame, a lower flexible frame and a dielectric elastomer film, and the dielectric elastomer film is disposed between the upper flexible frame and the lower flexible frame.

[0022] Preferably, step S2 specifically includes the following sub-steps:

[0023] S21, using the total mass, working voltage, working pressure and material stress of the pneumatic compensation flexible actuator as evaluation indicators, and establishing a mathematical expression for the performance index of the fuel tank based on the structural parameters determined in S1;

[0024] S22. According to the structural parameters and material density of each part of the pneumatic compensation type flexible actuator, the expression of the total mass of the pneumatic compensation type flexible actuator is established as follows:

[0025]

[0026] Wherein, m is the total mass of the pneumatically compensated flexible actuator; ρ1 is the density of the dielectric elastomer; α is the angle of the frame shape; ρ2 is the density of the flexible frame; a2 is the outer length of the plane shape of the flexible frame; n is the number of pneumatic synapses; H is the side length of the cross section of the pneumatic component; C6 is the depth of the joint part; a T is the cross-sectional length of the pneumatic synapse; b T is the cross-sectional width of the pneumatic synapse; r1 is the radius of the connection hole of the fixing piece; C2 is the longitudinal spacing between synapses; h S is the longitudinal depth of the gas channel; δ PZ is the longitudinal wall thickness of the synaptic gas chamber;

[0027] S23. According to the dielectric principle of pneumatic compensation flexible actuator, the working voltage expression is established as follows:

[0028]

[0029] Where U is the applied voltage; σ DEis the electrostatic pressure; ζ0 is the vacuum dielectric constant; ζ DE is the relative dielectric constant of the dielectric elastomer material; δ DE is the dielectric elastomer film thickness;

[0030] S24. According to the stress condition at the cross section of the dielectric elastomer film of the pneumatic compensation flexible actuator after longitudinal cutting, a mathematical model of the cross-sectional stress of the dielectric elastomer film is established:

[0031]

[0032] Where G is the total weight of the pneumatic components; S D is the conductive area of ​​the dielectric elastomer film; g is the gravitational acceleration; m PE is the mass of the pneumatic component; ρ3 is the density of the pneumatic component material;

[0033] S25. According to the stress condition of the cross section of the pneumatic component of the pneumatic compensation flexible actuator after longitudinal cutting, a mathematical model of the cross-sectional stress of the pneumatic component material is established:

[0034]

[0035] Among them, P s Supply gas pressure to the system;

[0036] Preferably, step S3 specifically includes the following sub-steps:

[0037] S31. Analyze the correlation between various structural parameters according to the connection or coordination of the structure, and preliminarily simplify the structural parameters;

[0038] S32. Consider the working status and usage requirements of the entire organization and determine the value range of key parameters.

[0039] Preferably, step S4 specifically includes the following sub-steps:

[0040] S41, combining the performance expression of the pneumatic compensation flexible actuator in S2 with the preliminarily simplified structural parameters in S31, perform sensitivity analysis on key parameters to obtain the sensitivity index of each parameter;

[0041] S42, comparing the relative sizes of the sensitivity indexes of the parameters, setting the parameters with smaller sensitivity indexes as fixed-value parameters and determining their values, and setting the parameters with larger sensitivity indexes as parameters to be analyzed for optimization design;

[0042] S43, establishing a multi-objective optimization expression by combining the mathematical expressions established in S22, S23, S24 and S25 with the finally selected constant parameters and the parameters to be analyzed.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The structural parameter optimization method of the pneumatically compensated flexible actuator based on dielectric elastomer of the present invention utilizes pneumatic components to compensate for the lack of deformation degree when the actuator is started, thereby solving the problem that the actuator has a hysteresis effect when it is started due to the nonlinear deformation process of the flexible material as a driving element, that is, the deformation effect during rapid actuation is inconsistent with that during normal operation, thereby improving the working performance of the actuator and facilitating the efficient design of flexible actuators that meet relevant performance indicators under different material thicknesses and volumes;

[0045] (2) The pneumatically compensated flexible actuator designed in the structural parameter optimization method of the pneumatically compensated flexible actuator based on dielectric elastomer of the present invention has the advantages of light weight, small pressure and air supply, and can meet the working limit of the material to the greatest extent, reduce the difficulty of production and energy supply, and can realize the structural size series design of the pneumatically compensated flexible actuator within a certain design range, significantly shortening the design time of a single finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a flow chart of the structural parameter optimization method of the pneumatic compensation type flexible actuator based on dielectric elastomer of the present invention;

[0047] Figure 2 A schematic diagram of the structure of a pneumatic compensation type actuator according to a method for optimizing the structural parameters of a pneumatic compensation type flexible actuator based on a dielectric elastomer of the present invention;

[0048] Figure 3 It is a schematic diagram of cross-sectional parameters of a pneumatically compensated flexible actuator according to a method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer of the present invention;

[0049] Figure 4 It is a schematic diagram of cross-sectional parameters of a pneumatic compensation type flexible actuator in the ventilation direction according to the structural parameter optimization method of the pneumatic compensation type flexible actuator based on a dielectric elastomer of the present invention;

[0050] Figure 5 It is the optimal solution set diagram of mass-voltage-dielectric elastomer stress of the structural parameter optimization method of the pneumatic compensation type flexible actuator based on the dielectric elastomer of the present invention;

[0051] Figure 6 It is an optimal solution set diagram of mass-voltage-pneumatic component stress of the pneumatic compensation flexible actuator structural parameter optimization method based on dielectric elastomer of the present invention.

[0052] Main reference numerals:

[0053] Dielectric elastomer driver 1, upper flexible frame 11, lower flexible frame 12, dielectric elastomer film 13, pneumatic component 2. DETAILED DESCRIPTION

[0054] In order to fully describe the technical content, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

[0055] The pneumatically compensated flexible actuator structure based on dielectric elastomer is as follows: Figure 2 As shown, it includes two parts, a dielectric elastomer driver 1 and a pneumatic component 2, wherein the pneumatic component 2 is arranged on the dielectric elastomer driver 1, and the dielectric elastomer driver 1 includes an upper flexible frame 11, a lower flexible frame 12 and a dielectric elastomer film 13, and the dielectric elastomer film 13 is arranged between the upper flexible frame 11 and the lower flexible frame 12. The initial working state of the driver is to supply voltage and air pressure, and the response speed of the pneumatic component 2 is greater than the response speed of the dielectric elastomer driver 1, compensating for the lack of deformation of the driver, and after the hysteresis effect time, only the driving voltage is supplied to drive the load.

[0056] Specifically, the present invention provides a method for optimizing the structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer, the process of which is as follows: Figure 1 As shown, the specific steps include:

[0057] S1. The working principle of the pneumatically compensated flexible actuator based on dielectric elastomer and the three-dimensional model of the parts are marked with dimensional parameters.

[0058] S2. Establishing the performance expression of the pneumatic compensation flexible actuator, which specifically includes the following sub-steps:

[0059] S21, taking the total mass, working voltage and material stress of the pneumatic compensation flexible actuator as evaluation indicators, and establishing an expression for the comprehensive performance of the actuator based on the dimensional parameters determined in S1;

[0060] S22. Establish a mathematical model of the total mass of the pneumatically compensated flexible actuator.

[0061] Specifically, step S22 includes the following sub-steps:

[0062] S221, the dielectric elastomer actuator 1 is composed of an upper flexible frame 11 and a lower flexible frame 12 adhered to a dielectric elastomer film 13, and a flexible electrode is coated in the center of the dielectric elastomer film 13. The mass expression of the dielectric elastomer actuator 1 is as follows:

[0063] m DE =m1+m2 (7)

[0064] Wherein, m1 is the mass of the dielectric elastomer film 13; m2 is the total mass of the upper flexible frame 11 and the lower flexible frame 12;

[0065]

[0066] Wherein, ρ1 is the density of the dielectric elastomer film 13; V1 is the volume of the dielectric elastomer film 13; a1 is the side length of the plane shape of the dielectric elastomer film 13; δ1 is the thickness of the dielectric elastomer film 13; α is the angle of the frame shape;

[0067]

[0068] Among them, ρ2 is the density of the flexible frame; V2 is the volume of the flexible frame; a2 is the outer length of the plane shape of the flexible frame; c2 is the vertical width of the flexible frame; δ2 is the thickness of the flexible frame;

[0069] Therefore, the total mass expression of the dielectric elastomer actuator 1 is as follows:

[0070]

[0071] S222, such as Figure 3 The figure shows a schematic diagram of the cross-section parameters of the pneumatic compensation flexible actuator. The internal gas flow channel is configured as a through cylindrical channel connecting the gas input end and each deformation chamber. Each deformation chamber is a rectangular parallelepiped, such as Figure 4 The figure shows a schematic diagram of the cross-sectional parameters of the pneumatic compensation flexible actuator in the ventilation direction. The mass expression of the pneumatic component 2 is as follows:

[0072] m PE =ρ3V3 (11)

[0073] Wherein, ρ3 is the density of the material of the pneumatic component 2; V3 is the volume of the pneumatic component 2;

[0074] V3=2V J +n·V T +V X -V K -V D (12)

[0075] Among them, V J is the volume of the joint; n is the number of pneumatic synapses; V T is the volume of a single pneumatic synapse; V X V is the volume of the lower base of the pneumatic component 2; K is the volume of the pore; V D is the volume of the gas channel;

[0076] V J =2H(He)C6 (13)

[0077] V T =2aT b T e (14)

[0078] V K =4πr1 2 ·(He) (15)

[0079] Wherein, H is the side length of the cross section of the pneumatic component 2; e is the height of the deformation space; C6 is the depth of the joint part; a T is the length of the pneumatic synapse cross section; b T is the width of the pneumatic synapse cross section; r1 is the radius of the connection hole of the fixing piece;

[0080] The volume of the base at the lower end of the pneumatic component 2 is related to the volume of the gas channel and the number of pneumatic synapses, and the expressions are as follows:

[0081] V X =H·(He)[n·a T +(n-1)C2] (16)

[0082]

[0083] Where C2 is the longitudinal spacing between synapses; r2 is the radius of the gas source input cross section; h S is the longitudinal depth of the gas channel; a P is the height of the gas chamber in the synaptic cross section; b P is the width of the gas chamber in the synaptic cross section; δ PZ is the longitudinal wall thickness of the synaptic gas chamber; S T The curved trapezoidal area of ​​the cross section of the connecting part between the gas source input channel and the chamber;

[0084] S T The area expression of a curved trapezoid is:

[0085]

[0086] Among them, δ PH is the transverse wall thickness of the synaptic gas chamber; c is the height of the curved trapezoid; θ is the central angle of the curved side;

[0087] Therefore, the volume of the pneumatic component 2 can be expressed by various processing parameters as follows:

[0088]

[0089] Therefore, the mass expression of pneumatic component 2 is as follows:

[0090]

[0091] Where ρ3 is the density of the pneumatic component material;

[0092] S223, without considering the fixing parts and external air pipes and wires, the total mass of the pneumatic compensation flexible actuator can be obtained from the total mass of the dielectric elastomer actuator 1 in S221 and the mass of the pneumatic component 2 in S222 as follows:

[0093]

[0094] Where m is the mass of the pneumatically compensated flexible actuator;

[0095] S23. According to the dielectric principle of the dielectric elastomer driver 1, a mathematical model of the working voltage is established:

[0096]

[0097] Where U is the applied voltage; σ DE is the electrostatic pressure; ζ0 is the vacuum dielectric constant; ζ DE is the relative dielectric constant of the dielectric elastomer material; δ DE is the dielectric elastomer film thickness;

[0098] S24, according to the force on the cross section of the dielectric elastomer film 13 of the pneumatic compensation flexible actuator after longitudinal cutting, a mathematical model of the cross-sectional stress of the dielectric elastomer film 13 is established:

[0099]

[0100] Where G is the total weight of the pneumatic component 2; S D is the conductive area of ​​the dielectric elastomer film; g is the gravitational acceleration; m PE is the mass of pneumatic component 2;

[0101] S25. According to the stress condition at the cross section of the pneumatic component 2 of the pneumatic compensation type flexible actuator after longitudinal cutting, a mathematical model of the cross-sectional stress of the pneumatic component material is established:

[0102]

[0103] Among them, P s is the air supply pressure of the system; f is the width of the lateral deformation space.

[0104] S3. Combined with the actual working conditions and application requirements, preliminarily screen the structural parameters in the performance expression and determine the value range;

[0105] S31. Analyze the relationship between the structural parameters due to the connection or coordination of their structures, and simplify the number of parameters according to the following geometric relationship;

[0106] h SThe longitudinal depth of the gas channel starts from one end of the joint, connects the gas chambers inside, and reaches the starting end or end of the last gas chamber, so there is a longest and shortest distance, so h S The value range is:

[0107] h S ∈[C6+(n-1)(a T +C2)+δ PZ ,C6+na T +(n-1)C2]

[0108] At the same time, if Figure 3 As shown, the cross-sectional parameters of the pneumatic compensation flexible actuator have the following relationship:

[0109] H=f+4δ PH +2b P (twenty one)

[0110] c=r2·sinθ (22)

[0111] b T =b P +2δ PH (twenty three);

[0112] S32. Considering the working status and usage requirements of the entire mechanism, determine the value range of key parameters, as shown in Table 1:

[0113] Table 1 Fixed parameters and their values ​​in size parameters

[0114]

[0115]

[0116] S4. Analyze the sensitivity of the structural parameters in each mathematical model, divide the structural parameters into fixed value parameters and parameters to be analyzed, and determine the multi-objective optimization function with total mass, working voltage, working pressure and material stress as the targets;

[0117] S41. Combining the performance expression of the pneumatic compensation flexible actuator in S2 with the structural size parameters preliminarily screened in S31, parameter sensitivity analysis is performed to obtain the sensitivity index of each parameter as shown in Tables 2 to 5. A short dash indicates that the sensitivity index is relatively low or the fixed value parameter has no numerical change;

[0118] Table 2 Quality formula parameter sensitivity index table

[0119]

[0120]

[0121] Table 3 Working voltage formula parameter sensitivity index table

[0122]

[0123] Table 4 Dielectric elastic body stress formula parameter sensitivity index table

[0124]

[0125] Table 5 Pneumatic component stress formula parameter sensitivity index table

[0126]

[0127] S42, comparing the relative sizes of the sensitivity indexes of the parameters, setting the parameters with smaller sensitivity indexes as fixed-value parameters and determining their values, and setting the parameters with larger sensitivity indexes as parameters to be analyzed for optimization design;

[0128] S43. According to the sensitivity analysis results, select a1 the side length of the dielectric elastomer plane shape, δ1 the thickness of the dielectric elastomer, c2 the vertical width of the flexible frame, δ2 the thickness of the flexible frame, f the lateral deformation space width, a P Synaptic cross-section gas chamber height, δ PH The transverse wall thickness of the synaptic gas chamber was used as the structural parameter to be analyzed;

[0129] S44, the mathematical expressions established in S22, S23, S24 and S25 are combined with the fixed value parameters and the parameters to be analyzed finally selected in S42 and S43 to establish a multi-objective optimization expression as follows:

[0130] f=min(f1,f2,f3,f4) (1)

[0131] S5. Considering the rationality of the relationship between the working gas pressure and structural parameters of the driver under actual working conditions, establish the constraints of the driver design:

[0132]

[0133] Where p is the working pressure and [σ] PE is the allowable stress of the material of pneumatic component 2; S2 is the area of ​​the material under stress; S1 is the actual area of ​​the cross section under gas pressure;

[0134] The thickness and side length of the packaging film material have the following constraint relationship:

[0135]

[0136] S6. Utilize the multi-objective optimization function in S4 and the constraints in S5 to optimize the structural parameters of the pneumatic compensation flexible actuator based on the multi-objective optimization algorithm, comprehensively analyze the optimization results and make choices, select a set of solutions with appropriate and better results from the optimal solution set, and obtain the optimal structural parameters of the actuator.

[0137] The structural parameter optimization method of the pneumatic compensation type flexible actuator based on dielectric elastomer of the present invention is described in detail below in conjunction with specific embodiments.

[0138] The flexible frame of the dielectric elastomer actuator is made of PE material with a thickness of 1.5 mm. The dielectric elastomer is made of 3MVHB 4910 substrate with a thickness of 1 mm. They are cut into rhombus shapes with an angle of 60° and then adhered as a whole. The mass expression of the dielectric elastomer actuator is as follows:

[0139]

[0140] From formulas (20) and (24), the mass expression of the pneumatic compensation flexible actuator can be obtained as follows:

[0141]

[0142] According to step S6, the results of the result parameter optimization are comprehensively analyzed and selected, and the following can be obtained: Figure 5 The optimal solution set diagram of mass-voltage-dielectric elastic body stress of the pneumatic compensation actuator structural parameter optimization method shown in Figure 6 The optimal solution set diagram of mass-voltage-pneumatic component stress of the pneumatic compensation drive structural parameter optimization method is shown. A set of solutions with suitable and better results is selected from the optimal solution set to obtain the optimal structural design parameters of the drive.

[0143] Based on this, a comprehensive analysis of the optimal solution set is conducted. Under the conditions that the mass is not greater than 0.1kg, the working voltage is not less than 7kV, and the stress of the dielectric elastomer material and the pneumatic component material is not greater than 3000Pa and 0.9MPa respectively, the optimal structural parameters of the actuator are obtained as follows: the side length of the dielectric elastomer plane is 50.89mm, the thickness of the dielectric elastomer is 1.13mm, the vertical width of the flexible frame is 36.73mm, the thickness of the flexible frame is 1.01mm, the width of the lateral deformation space is 2.08mm, the height of the synaptic cross-section gas chamber is 2.05mm, and the lateral wall thickness of the synaptic gas chamber is 4.25mm. In practical applications, considering the processing accuracy, the above structural parameters are all taken as corresponding approximate values.

[0144] The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer, characterized in that: It specifically includes the following steps: S1. Based on the working principle of the pneumatic compensation flexible actuator of dielectric elastomer, determine the structural dimension parameters of the actuator configuration; S2. Taking the mass, working voltage and material stress of the dielectric elastomer drive unit as evaluation indicators, taking the mass and material stress of the air pressure compensation unit as evaluation indicators, using structural parameters to express the performance expression of the pneumatic compensation flexible actuator, and establishing a mathematical model of the total mass, working voltage and material stress of the pneumatic compensation flexible actuator; S3. Combined with the actual working conditions and application requirements, the structural parameters in the performance expression of the pneumatic compensation flexible actuator are preliminarily simplified, and the parameter value range is determined; S4. Analyze the sensitivity index of key structural parameters in each mathematical model. When the sensitivity index is small, it is divided into fixed parameters. When the sensitivity index is large, it is divided into parameters to be analyzed. Determine the simplified structural parameters to express the multi-objective optimization function with total mass, working voltage and material stress as the target; establish the multi-objective optimization expression as follows: f=min(f1,f2,f3,f4) (1) Wherein, f1 represents the total mass of the pneumatic compensation flexible actuator; f2 represents the working voltage of the pneumatic compensation flexible actuator; f3 represents the stress at the cross section of the dielectric elastomer film of the pneumatic compensation flexible actuator after longitudinal cutting; f4 represents the stress at the cross section of the pneumatic component of the pneumatic compensation flexible actuator after longitudinal cutting; S5. Considering the rationality of the volume of the pneumatic compensation flexible actuator under actual working conditions, the constraints for the design of the pneumatic compensation flexible actuator are established according to the relationship between the working gas pressure and the structural parameters: Where p is the working pressure and [σ] PE is the allowable stress of the pneumatic component material; S2 is the area of ​​the material under stress; S1 is the actual area of ​​the cross section under gas pressure; e is the height of the deformation space; r2 is the radius of the gas source input cross section; a P is the height of the gas chamber in the synaptic cross section; b P is the width of the gas chamber in the synaptic cross section; δ PH is the transverse wall thickness of the synaptic gas chamber; f is the width of the transverse deformation space; c is the height of the curved trapezoid; θ is the central angle of the curved edge; There is a constraint relationship between the thickness and side length of the packaging film material: Among them, δ1 is the thickness of the dielectric elastomer; δ2 is the thickness of the flexible frame; a1 is the side length of the plane shape of the dielectric elastomer; c2 is the vertical width of the flexible frame; S6. Utilizing the multi-objective optimization function obtained in S4 and the constraints obtained in S5, the drive structural parameters are optimized and an optimal solution set is obtained. A set of solutions is determined from the optimal solution set to obtain the optimal structural parameters of the pneumatically compensated flexible drive.

2. The method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer according to claim 1, characterized in that: The driver includes a dielectric elastomer driver and a pneumatic assembly, wherein the pneumatic assembly is disposed on the dielectric elastomer driver.

3. The method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer according to claim 2, characterized in that: The driver includes an upper flexible frame, a lower flexible frame, and a dielectric elastomer film disposed between the upper flexible frame and the lower flexible frame.

4. The method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer according to claim 1, characterized in that: Step S2 specifically includes the following sub-steps: S21, using the total mass, working voltage, working pressure and material stress of the pneumatic compensation flexible actuator as evaluation indicators, and establishing a mathematical expression for the performance index of the fuel tank based on the structural parameters determined in S1; S22. According to the structural parameters and material density of each part of the pneumatic compensation type flexible actuator, the expression of the total mass of the pneumatic compensation type flexible actuator is established as follows: Wherein, m is the total mass of the pneumatically compensated flexible actuator; ρ1 is the density of the dielectric elastomer; α is the angle of the frame shape; ρ2 is the density of the flexible frame; a2 is the outer length of the plane shape of the flexible frame; n is the number of pneumatic synapses; H is the side length of the cross section of the pneumatic component; C6 is the depth of the joint part; a T is the cross-sectional length of the pneumatic synapse; b T is the cross-sectional width of the pneumatic synapse; r1 is the radius of the connection hole of the fixing piece; C2 is the longitudinal spacing between synapses; h S is the longitudinal depth of the gas channel; δ PZ is the longitudinal wall thickness of the synaptic gas chamber; S23. According to the dielectric principle of pneumatic compensation flexible actuator, the working voltage expression is established as follows: Where U is the applied voltage; ζ0 is the dielectric constant of vacuum; ζ DE is the relative dielectric constant of the dielectric elastomer material; δ DE is the dielectric elastomer film thickness; σ DE Dielectric elastomer film cross-sectional stress; S24. According to the stress condition at the cross section of the dielectric elastomer film of the pneumatic compensation flexible actuator after longitudinal cutting, a mathematical model of the cross-sectional stress of the dielectric elastomer film is established: Where G is the total weight of the pneumatic components; S D is the conductive area of ​​the dielectric elastomer film; g is the gravitational acceleration; m PE is the mass of the pneumatic component; ρ3 is the density of the pneumatic component material; S25. According to the stress condition of the cross section of the pneumatic component of the pneumatic compensation flexible actuator after longitudinal cutting, a mathematical model of the cross-sectional stress of the pneumatic component material is established: Among them, P s Supply air pressure to the system.

5. The method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer according to claim 1, characterized in that: Step S3 specifically includes the following sub-steps: S31. Analyze the correlation between various structural parameters according to the connection or coordination of the structure, and preliminarily simplify the structural parameters; S32. Consider the working status and usage requirements of the entire organization and determine the value range of key parameters.

6. The method for optimizing structural parameters of a pneumatically compensated flexible actuator based on a dielectric elastomer according to claim 1, characterized in that: Step S4 specifically includes the following sub-steps: S41, combining the performance expression of the pneumatic compensation flexible actuator in S2 with the preliminarily simplified structural parameters in S31, perform sensitivity analysis on key parameters to obtain the sensitivity index of each parameter; S42, comparing the relative sizes of the sensitivity indexes of the parameters, setting the parameters with smaller sensitivity indexes as fixed-value parameters and determining their values, and setting the parameters with larger sensitivity indexes as parameters to be analyzed for optimization design; S43, establishing a multi-objective optimization expression by combining the mathematical expressions established in S22, S23, S24 and S25 with the finally selected constant parameters and the parameters to be analyzed.

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