Negative pressure type wall-climbing robot adsorption force calculation method based on numerical simulation

Abstract

The invention discloses a negative pressure type wall-climbing robot adsorption force calculation method based on numerical simulation, and belongs to the technical field of calculation methods, numerical simulation is carried out through fluid mechanics calculation software Fluent in finite element calculation software ANSYS, the change of the adsorption force of a wall-climbing robot under different wind speeds and different gap heights is obtained through simulation, and the adsorption force of the wall-climbing robot is calculated. And nonlinear fitting is carried out on the change of the adsorption force along with the gap height and the wind speed by utilizing a Gamma distribution function form, so that a change formula of the adsorption force of the wall-climbing robot along with the gap height and the wind speed of the bottom plate and the adsorption surface is obtained. In practical application, the adsorption force of the wall-climbing robot is determined according to a formula, the adsorption force can be adjusted by comprehensively controlling the gap height between the bottom plate of the wall-climbing robot and the adsorption surface and the wind speed of the fan, and guidance is provided for optimization design of the wall-climbing robot. By means of the wall-climbing robot, limitation of the working environment on the wall-climbing robot can be reduced, and meanwhile the working efficiency of the wall-climbing robot is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of computing methods, and particularly relates to a negative pressure type wall-climbing robot adsorption force calculation method based on numerical simulation. BACKGROUND

[0002] At present, for the high-altitude work scene of infrastructure structures that are difficult to reach or contact, the traditional work method usually relies on professional vehicles or tools, such as aerial ladders, cranes, scaffolds, baskets and ladders, or uses magnetic adsorption wall-climbing technology to use permanent magnets or electromagnets to generate adsorption force on a magnetically conductive surface (such as a steel structure, a ship or a storage tank) to work. However, the above-mentioned means has many problems such as long preparation period, high work cost, safety hazards and can only be applied to the surface of ferromagnetic materials.

[0003] The negative pressure type wall-climbing robot can overcome the limitations and risks of traditional methods in vertical surface work and solve the shortcomings of early wall-climbing technology. The negative pressure type wall-climbing robot is based on the principle of vacuum negative pressure adsorption and can fundamentally change the high-altitude work method. It can stably climb on any relatively flat and airtight surface (glass, concrete, ceramic tile, metal, composite material, etc.), breaking through the material limitation of magnetic adsorption.

[0004] However, the negative pressure type wall-climbing robot will encounter problems such as terrain undulation and cracks during work, which will affect the air inlet channel between the robot bottom plate and the adsorption surface, and further affect the adsorption force of the robot. The existing solution is usually to increase the wind speed or lower the bottom plate, but due to the weight limitation of the negative pressure type wall-climbing robot, these methods will increase the working energy consumption of the robot and limit the working environment of the robot.

[0005] Therefore, the application develops an adsorption force control method which can adjust the adsorption force of the robot according to different environments and greatly improve the working efficiency of the robot. SUMMARY

[0006] In order to solve the above problems, the application provides a negative pressure type wall-climbing robot adsorption force calculation method based on numerical simulation.

[0007] To achieve the above purpose, the technical scheme adopted by the application is as follows:

[0008] A negative pressure type wall-climbing robot adsorption force calculation method based on numerical simulation, comprising the following steps:

[0009] S1, using the finite element calculation software ANSYS to establish a robot model of the wall-climbing robot and performing mesh division, and obtaining the adsorption force data of the wall-climbing robot under different wind speeds and different adsorption gap heights through condition setting;

[0010] S2, according to the simulation data obtained in step S1, the function form of Gamma distribution is used to carry out nonlinear fitting on the change of the adsorption force with the gap height and the wind speed, and the adsorption force F of the wall-climbing robot is obtained f The calculation formula is as follows:

[0011]

[0012] In the formula, Γ (alpha) is the Gamma function, h is the gap height between the bottom plate of the wall-climbing robot and the adsorption surface, c is a scaling factor, alpha is a shape parameter, and theta is a scale parameter.

[0013] Further, in step S1, the gap edge between the bottom plate of the robot model and the adsorption surface is the air inlet, the top of the robot model is provided with the outlet of the fan, and the size of the bottom plate of the robot model is 0.545m*1m, and the number of fans is 3.

[0014] Further, in step S1, the wall-climbing robot under different wind speeds and different gap heights is calculated by using the fluid mechanics calculation software Fluent in the finite element calculation software ANSYS, and the adsorption force data of the wall-climbing robot is obtained.

[0015] Further, in step S2, the function of the adsorption force changing with the gap height under different wind speeds is fitted by using the least square method, and the expression of the scaling factor c, the shape parameter alpha and the scale parameter theta is obtained.

[0016] ;

[0017] ;

[0018] ;

[0019] In the formula, v is the wind speed of the fan;

[0020] Further, the curve fitting formula of the adsorption force F of the wall-climbing robot changing with the gap height h and the wind speed v is as follows: f Further, the curve fitting formula of the adsorption force F of the wall-climbing robot changing with the gap height h and the wind speed v is as follows:

[0021] .

[0022] Compared with the prior art, the technical progress obtained by the present application is that:

[0023] The application carries out numerical simulation by fluid mechanics calculation software Fluent in finite element calculation software ANSYS, simulates the change of the adsorption force of the wall-climbing robot under different wind speeds and different gap heights, and carries out nonlinear fitting on the change of the adsorption force with the gap height and the wind speed by using the function form of Gamma distribution, and obtains the formula of the change of the adsorption force of the wall-climbing robot with the gap height between the bottom plate and the adsorption surface and the wind speed. In actual application, the adsorption force of the wall-climbing robot is determined according to the fitting formula, and the adsorption force can be adjusted by comprehensively controlling the gap height between the bottom plate and the adsorption surface of the wall-climbing robot and the wind speed of the fan, so as to provide guidance for the optimization design of the wall-climbing robot. The application can reduce the limitation of the working environment on the wall-climbing robot, and improve the working efficiency of the wall-climbing robot. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, illustrate the application, and are used to explain the application together with the embodiments of the application, and do not constitute a limitation on the application.

[0025] In the drawings:

[0026] Figure 1 It is a structural schematic diagram of the robot model in the embodiment of the application;

[0027] Figure 2 It is a fitting curve diagram of the change of the adsorption force with the gap height under different wind speeds in the embodiment of the application;

[0028] Figure 3 It is a curve diagram of the change of the scaling factor, the shape parameter and the scale parameter with the wind speed in the embodiment of the application.

[0029] In the drawings:

[0030] 1-robot model; 2-adsorption surface; A-enlarged view of the gap height between the bottom plate of the robot model and the adsorption surface. DETAILED DESCRIPTION

[0031] The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the application will be described below with reference to the drawings.

[0032] As known, the important factors affecting the adsorption force of the negative pressure type wall-climbing robot include the following three aspects: external factors, air inlet area and air suction capacity. The above three factors are analyzed as follows:

[0033] 1, the external factors (such as environmental temperature, humidity, external wind speed, contact surface material) generally have less influence on the adsorption force, and the frequency is low, so the influence of the factor is not considered in the calculation.

[0034] 2. The suction capacity is determined by the base plate area, fan speed (rotation speed), and number of fans. Preliminary comparative calculations, as shown in Table 1, indicate that more fans result in greater suction force from the base plate, but also increase the robot's own weight. Therefore, considering the negative pressure robot's weight, workload, and working environment (facilitating entry into confined spaces and adapting to curved surfaces), this invention selects a base plate length of 0.545 meters and a width of 1 meter, with three fans as the optimal value, to calculate the suction force generated per unit width. Therefore, this invention only considers the influence of fan speed variations in its calculations, denoted by v, in m / s.

[0035] Table 1. Effect of the number of fans on the adsorption force

[0036]

[0037] Note: The data in Table 1 were obtained under the conditions of a robot base plate length of 545mm, a ground clearance of 5mm, and a wind speed of 15m / s.

[0038] 3. Air intake area: After the size of the base plate is determined, the air intake area is determined by the height of the base plate from the ground, denoted by h, in cm.

[0039] Based on the above analysis, it can be seen that the influence of external factors is relatively small. This invention limits the robot's base plate size to 0.545m*1m. With 3 fans selected, the main analysis focuses on the influence of fan speed v and the height h of the base plate's ground clearance on the suction force of the negative pressure robot per unit width.

[0040] The present invention will be described in detail below through specific embodiments.

[0041] This invention provides a method for calculating the adhesion force of a negative pressure wall-climbing robot based on numerical simulation, comprising the following steps:

[0042] S1. A robot model of the wall-climbing robot was established using the finite element method software ANSYS, such as... Figure 1 As shown;

[0043] The mesh was generated, and after setting the conditions, the wall-climbing robot was calculated using Fluent, a fluid dynamics software in ANSYS, for different wind speeds and gap heights. The simulation results of the wall-climbing robot's adsorption force are shown in Table 2.

[0044]

[0045] exist Figure 1 In the model, the edge of the gap between the bottom plate and the adsorption surface of the robot model serves as the airflow inlet, and the top of the robot model is equipped with a fan outlet. The boundary definitions in the finite element calculation software are summarized in Table 3.

[0046] .

[0047] S2, according to the simulation data obtained in step S1, the variation of the adsorption force with the gap height and the wind speed is nonlinearly fitted by using the function form of the Gamma distribution, and the adsorption force F of the wall-climbing robot is obtained f The calculation formula is as follows:

[0048]

[0049] In the formula, Γ(α) is the Gamma function, h is the gap height between the bottom plate of the wall-climbing robot and the adsorption surface, c is the scaling factor, α is the shape parameter, and θ is the scale parameter.

[0050] The scaling factor c, the shape parameter α, and the scale parameter θ in the formula are obtained by fitting the function of the adsorption force with the gap height under different wind speeds by using the least square method, and are shown in the following table:

[0051]

[0052] It can be observed from the above table that the scaling factor c, the shape parameter α, and the scale parameter θ respectively present different development trends with the change of the wind speed, and the formula of the scaling factor c, the shape parameter α, and the scale parameter θ is further obtained as follows:

[0053] ;

[0054] ;

[0055] ;

[0056] In the formula, v is the wind speed of the fan;

[0057] The curve fitting formula of the adsorption force F of the wall-climbing robot with the variation of the gap height h and the wind speed v is as follows: f

[0058] .

[0059] ​In summary, the application is simulated by the fluid mechanics calculation software Fluent in the finite element calculation software ANSYS, the change of the adsorption force of the wall-climbing robot under different wind speeds and different gap heights is simulated, the change of the adsorption force with the gap height and the wind speed is nonlinearly fitted by using the function form of Gamma distribution, and the formula of the change of the adsorption force of the wall-climbing robot with the gap height between the bottom plate and the adsorption surface and the wind speed is obtained. In actual application, the adsorption force of the wall-climbing robot is determined according to the fitting formula, the gap height between the bottom plate and the adsorption surface of the wall-climbing robot and the wind speed of the fan are comprehensively controlled, so that the adsorption force can be adjusted, and the optimization design of the wall-climbing robot is guided. The application can reduce the limitation of the working environment on the wall-climbing robot, and improve the working efficiency of the wall-climbing robot.

[0060] Finally, it should be noted that: the above only for the preferred embodiments of the application, and not for the purpose of limiting the application, although the application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can be modified to the technical solutions recorded in the foregoing embodiments, or equivalent replacement of some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the scope of protection of the claims of the application.

Claims

1. A numerical simulation-based negative pressure wall-climbing robot suction force calculation method, characterized in that, The method comprises the following steps: S1, using finite element calculation software ANSYS to establish a robot model of the wall-climbing robot, and performing mesh division, and through condition setting, obtaining adsorption force data of the wall-climbing robot under different wind speeds and different adsorption gap heights; S2, according to the simulation data obtained in step S1, the function form of Gamma distribution is used to carry out nonlinear fitting on the change of adsorption force with gap height and wind speed, and the adsorption force F of the wall-climbing robot is obtained f Calculation formula; where Γ(α) is the Gamma function, h is the gap height between the base plate of the wall-climbing robot and the adsorbing surface; c is the scaling factor, a is the shape parameter, and Θ is the scale parameter.

2. The numerical simulation-based negative pressure type wall-climbing robot suction force calculation method according to claim 1, characterized in that: In step S1, the gap edge between the bottom plate of the robot model and the adsorption surface is the air inlet, and the top of the robot model is provided with the outlet of the fan; the size of the bottom plate of the robot model is 0.545m*1m, and the number of the fans is 3.

3. The method according to claim 1, wherein the method is characterized in that: In step S1, the wall-climbing robot under different wind speeds and different gap heights is calculated through the fluid mechanics calculation software Fluent in the finite element calculation software ANSYS, and the adsorption force data of the wall-climbing robot is obtained.

4. The numerical simulation-based negative pressure type wall-climbing robot suction force calculation method according to claim 1, characterized in that: In step S2, the function of the adsorption force changing with the gap height under different wind speeds is fitted through the least square method, and the expression of the scaling factor c, the shape parameter a and the scale parameter theta is obtained: ； ； ； In the formula, v is the wind speed of the fan. Further, the wall-climbing robot suction force F is obtained f The curve fitting formula with the gap height h and the wind speed v is as follows: 。

Images