A control method of an underwater wireless power transmission device
By generating an inverse model using adaptive filtering theory as an inverse controller, the problem of poor control performance of underwater wireless power transmission devices in underwater environments is solved, achieving fast response and high-precision wireless power transmission.
Patent Information
- Application Number
- CN202210495185.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-05-07
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2042-05-07
AI Technical Summary
Traditional wireless power transfer devices suffer from poor control performance in underwater environments due to parameter shifts and changes in model structure. Furthermore, the reliability and real-time performance of feedback control are affected by the complex underwater electromagnetic environment.
Adaptive filtering theory is adopted, and an inverse model is generated through inverse modeling as an inverse controller. The inverse model is generated by the adaptive filtering algorithm to dynamically track the changes of the underwater wireless power transmission device and realize real-time control without feedback signals.
It improves the response speed and output accuracy of underwater wireless power transmission devices, enhances the stability and flexibility of the system, and avoids control deviations in underwater environments using traditional methods.
Smart Images
Figure CN114977529B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of wireless energy and information transmission, and particularly relates to a control method of an underwater wireless electric energy transmission device. BACKGROUND
[0002] Most work equipment needs energy supply, and traditional energy transmission methods mostly transmit energy to terminal products through contact plug-in interfaces. Such transmission methods can cause friction and generate electric sparks, thereby affecting the safety and reliability of electrical equipment. Traditional wired power transmission methods cannot meet the needs of some special application scenarios, such as mines and underwater environments.
[0003] Wireless energy transmission technology can free us from traditional energy transmission methods, and achieve non-contact energy transmission through electromagnetic radiation, electric field coupling, magnetic field coupling, ultrasonic waves and the like, thereby avoiding problems such as wear and tear caused by plug-in operations and short circuits caused by sealing leaks, prolonging the working time of equipment underwater, and improving working flexibility and working range. Therefore, wireless electric energy transmission technology has been applied in some special scenarios.
[0004] Especially in underwater environments, wireless electric energy transmission devices can have parameter deviation, model structure change, transmission characteristic change and the like. The transmission model changes due to the influence of underwater environments, thereby affecting the control effect of traditional control methods that depend on system mathematical models.
[0005] In addition, in traditional feedback control, the control process has high requirements for the real-time performance and reliability of feedback channels. The electromagnetic environment underwater is complex, and threatens the reliability and real-time performance of feedback communication, which can cause unreliable system output results under certain conditions. Therefore, it is challenging for control methods based on traditional modeling methods to control wireless electric energy transmission devices in underwater environments. SUMMARY
[0006] The purpose of the present application is to overcome the deficiencies in the prior art and provide a control method of an underwater wireless electric energy transmission device. Through the method, the output voltage of the underwater wireless electric energy transmission device can be controlled after the system model of the underwater wireless electric energy transmission device changes due to underwater environments.
[0007] The technical solution adopted by the present application to solve the technical problem is as follows: according to the adaptive filtering theory and different actual working conditions, a suitable adaptive filtering algorithm is selected for inverse modeling of the underwater wireless electric energy transmission device, and an inverse model of the underwater wireless electric energy transmission device is obtained. The inverse model is used as an inverse controller of the underwater wireless electric energy transmission device.
[0008] First, the input and output voltage values of the underwater wireless electric energy transmission device are collected through a primary sensor;
[0009] The input and output voltage values collected by the primary sensor are converted from analog to digital to obtain two sets of discrete arrays, which are then stored in a computer for use in generating an inverse model during the inverse modeling process.
[0010] The inverse modeling process is an inverse model generated internally by the computer using an inverse modeling algorithm. The generation process first uses the output voltage values of the two sets of discrete arrays as the input voltage values for inverse modeling. The output voltage value of the inverse modeling is calculated by the inverse modeling algorithm using the input voltage values of the inverse modeling. The output voltage value of the inverse modeling is then compared with the input voltage value of the underwater wireless power transmission device to obtain the error. The error is then used to continuously adjust the weight vector of the inverse modeling algorithm to obtain an updated weight vector. The obtained weight vector is the inverse model of the underwater wireless power transmission device. The inverse model is then used as the inverse controller of the underwater wireless power transmission device.
[0011] The formula for calculating the output voltage value using the inverse modeling algorithm is:
[0012] y(k)=x T (k)w(k),
[0013] Where w(k) represents the weight vector at time k, and x(k) is the input voltage value of the inverse modeling algorithm at time k, x(k) = [x(k), x(k-1), ..., x(k-M+1)] T y(k) represents the output voltage value calculated by the inverse modeling algorithm, and T is the transpose symbol for matrix operations.
[0014] Then, the desired output voltage value of the underwater wireless power transmission device is calculated by the inverse controller, thus obtaining the input voltage value of the underwater wireless power transmission device;
[0015] Furthermore, the input voltage value of the aforementioned underwater wireless power transmission device is compared to obtain the error. Then, the error is used to continuously adjust the weight vector of the inverse modeling algorithm to obtain an updated weight vector. The inverse modeling algorithm updates the inverse model using the error e(k). The specific update formula is:
[0016] e(k)=d(k)-y(k)=d(k)-x T (k)w(k)
[0017] w(k+1)=w(k)+μX(k)[X T (k)X(k)] -1 e(k);
[0018] Wherein X(k)=[x(k), x(k-1),..., x(k-P+1)] represents the input voltage value matrix of the inverse modeling algorithm at k time, M is the weight vector length, P is the projection order of the inverse modeling algorithm, and mu is the step length of the inverse modeling algorithm. d(k) represents the expected voltage value of the inverse modeling algorithm. w(k) is the weight vector at k time, and the inverse model can be represented by the weight vector. w(k) is also the inverse model at k time.
[0019] Adjust the input voltage of the underwater wireless power transmission device according to the input voltage value of the underwater wireless power transmission device.
[0020] Finally, output the adjusted input voltage to an external load device connected to the output end of the underwater wireless power transmission device.
[0021] Specifically, the inverse model obtained by the inverse modeling serves as an inverse controller of the underwater wireless power transmission device, and the input voltage value of the underwater wireless power transmission device is calculated.
[0022] Further, the expected output voltage value of the underwater wireless power transmission device is set in advance, and the input voltage value of the underwater wireless power transmission device can be obtained by calculating the inverse model. The calculation method is as follows:
[0023] y(k) = x T (k)w(k);
[0024] The calculation process of the inverse model is the operation process of the inverse controller of the underwater wireless power transmission device.
[0025] Further, the update of the inverse model in the inverse modeling is through least square, affine projection algorithm or least fourth-order moment affine projection algorithm.
[0026] The beneficial effects of the present application are as follows:
[0027] According to the adaptive inverse control theory, compared with the traditional feedback control method, the control method can eliminate the propagation and processing time of the feedback signal at the output end of the system, and finally improve the response speed of the system.
[0028] The change of the system transmission model caused by the underwater environment will cause the control result of the traditional control method relying on accurate modeling to deviate. The control method is based on adaptive modeling, which can dynamically track the changed transmission model, and finally improve the output accuracy of the system. BRIEF DESCRIPTION OF DRAWINGS
[0029] Figure 1 is a schematic diagram of the inverse modeling structure of the control method; Figure 1 Figure 1 is a schematic diagram of the inverse modeling structure of the control method;
[0030] Figure 1 is a schematic diagram of the inverse modeling structure of the control method; Figure 2The structure diagram of the control method is shown in the figure. DETAILED DESCRIPTION
[0031] The application will be further described below in conjunction with the examples. The following examples are only used to help understand the application. It should be pointed out that for those skilled in the art, some improvements and modifications can be made to the application without departing from the principles of the application, and these improvements and modifications also fall within the protection scope of the claims of the application.
[0032] As shown in the example, the primary sensor is used to collect the input voltage and output voltage of the underwater wireless power transmission device. Figure 1
[0033] The collected input and output voltage signals are analog-digital converted into two groups of discrete arrays and stored in the computer.
[0034] The two groups of discrete arrays stored in the computer are used as reference signals for inverse modeling.
[0035] In the computer, the output voltage value of the underwater wireless power transmission device is used as the input voltage value for inverse modeling. The output voltage value obtained after the inverse modeling calculation is compared with the input voltage value of the underwater wireless power transmission device to obtain the error value e(k). In addition, the inverse modeling algorithm can be implemented by using C++ or C# language.
[0036] The formula for calculating the output voltage value by inverse modeling is:
[0037] y(k)=x T (k)w(k)
[0038] wherein w(k) represents the weight vector at time k, x(k) represents the input voltage value of the inverse modeling algorithm at time k, x(k)=[x(k), x(k-1),..., x(k-M+1)] T , and y(k) represents the output voltage value calculated by the inverse modeling algorithm.
[0039] The calculation method of the error value is:
[0040] e(k)=d(k)-y(k)=d(k)-x T (k)w(k)
[0041] wherein d(k) represents the expected voltage value of the inverse modeling algorithm.
[0042] The process of inverse modeling adjusts the weight vector through the built-in adaptive algorithm to obtain the updated weight vector. The weight vector obtained by the inverse modeling is the inverse model of the underwater wireless power transmission device, and the updated inverse model updates the calculation process as follows:
[0043] w(k+1)=w(k)+μX(k)[X T (k)X(k)] -1 e(k)
[0044] Where X(k) = [x(k), x(k-1), ..., x(k-P+1)] represents the matrix of input voltage values M×P of the inverse modeling algorithm at time k, where M is the length of the weight vector, P is the projection order of the inverse modeling algorithm, and μ is the step size of the inverse modeling algorithm.
[0045] The inverse model can be represented by a weight vector, and the updated weight vector w(k+1) is the updated inverse model.
[0046] Specifically, the update method for the inverse model in inverse modeling can be different depending on the actual needs. For example, least squares, affine projection algorithm, least fourth-moment affine projection algorithm, etc.
[0047] like Figure 2 As shown, the pre-set desired output voltage value is input into the inverse controller in the computer. The inverse controller is the inverse model obtained by inverse modeling. The voltage value output by the inverse controller is the input voltage value required by the underwater wireless power transmission device (the pre-set desired output voltage value is a discrete array that changes with time. That is, the desired output voltage value of the underwater wireless power transmission device is not constant, but changes with time).
[0048] In computers, the update calculation process of the inverse model obtained from inverse modeling and the calculation process of the inverse controller for the preset desired output voltage value are performed simultaneously. During the operation of the underwater wireless power transfer device, these two processes are continuous to ensure that the inverse model obtained from inverse modeling closely approximates the inverse model of the underwater wireless power transfer device. Thus, the inverse controller is updated once at every moment.
[0049] Based on the voltage value calculated by the reverse controller, the input voltage of the underwater wireless power transmission device is adjusted. The adjustment can be made in many ways, such as full-bridge inverter phase-shift control.
[0050] The output of the underwater wireless power transmission device is connected to an external load device.
[0051] The basic idea of the inverse control method is to obtain the inverse model of the underwater wireless power transmission device in order to calculate the input voltage value required when the underwater wireless power transmission device outputs the desired voltage.
[0052] Let the underwater wireless power transfer device be P(z), and the inverse controller and inverse model be C(z). Through the inverse modeling process, the inverse controller and inverse model C(z) approximate the inverse model of the underwater wireless power transfer device. The total transfer function of the inverse controller and the underwater wireless power transmission device in series Therefore, the expected output voltage value of the underwater wireless power transmission device is input at the input end of the inverse controller, and the final output voltage of the whole system is the expected output voltage.
[0053] The inverse controller and the inverse model C(z) are continuously updated through the inverse modeling process, so that the inverse controller and the inverse model C(z) always approximate the inverse model of the underwater wireless power transmission device after the parameter drift and structure change of the system model of the underwater wireless power transmission device in the underwater environment. Through the control method of the application, the final output voltage of the underwater wireless power transmission device can be kept approximately equal to the input voltage value of the inverse controller C(z), and the purpose of finally realizing the stable output voltage value of the system is achieved.
[0054] In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.
Claims
1. A control method for an underwater wireless power transmission device, characterized in that, include: First, the input and output voltage values of the underwater wireless power transmission device are collected using primary sensors; The input and output voltage values collected by the primary sensor are converted from analog to digital to obtain two sets of discrete arrays, which are then stored in a computer for use in generating an inverse model during the inverse modeling process. The inverse modeling process involves generating an inverse model internally using an inverse modeling algorithm. The generation process first uses the output voltage values of the two discrete arrays as the input voltage values for inverse modeling. The input voltage values are then used by the inverse modeling algorithm to calculate the output voltage value of the inverse modeling. This output voltage value is then compared with the input voltage value of the underwater wireless power transmission device to obtain the error. The error is then used to continuously adjust the weight vector of the inverse modeling algorithm to obtain an updated weight vector. This updated weight vector is the inverse model of the underwater wireless power transmission device, which is then used as the inverse controller of the underwater wireless power transmission device. The inverse modeling algorithm updates the inverse model using the error e(k). The specific update formula is as follows: e(k)=d(k)-y(k)=d(k)-x T (k)w(k) w(k+1)=w(k)+μX(k)[X T (k)X(k)] -1 e(k); Where X(k) = [x(k), x(k-1), ..., x(k-P+1)] represents the matrix of input voltage values M×P of the inverse modeling algorithm at time k, M is the length of the weight vector, P is the projection order of the inverse modeling algorithm, μ is the step size of the inverse modeling algorithm, d(k) represents the expected voltage value of the inverse modeling algorithm, and w(k) is the weight vector at time k. The inverse model can be represented by the weight vector, and w(k) is also the inverse model at time k. Then, the desired output voltage value of the underwater wireless power transmission device is calculated by the inverse controller, thus obtaining the input voltage value of the underwater wireless power transmission device; specifically, the inverse model obtained by the inverse modeling is used as the inverse controller of the underwater wireless power transmission device, and the input voltage value of the underwater wireless power transmission device is calculated; after calculating the desired output voltage value of the underwater wireless power transmission device by the inverse model, the input voltage value of the underwater wireless power transmission device can be obtained. Its calculation expression is: y(k)=x T (k)w(k); The calculation process of the inverse model is the operation process of the inverse controller of the underwater wireless power transmission device; Furthermore, the inverse model update in the inverse modeling is achieved through least squares, affine projection algorithm, or least fourth-moment affine projection algorithm. Adjust the input voltage of the underwater wireless power transmission device according to the input voltage value of the underwater wireless power transmission device; Finally, the adjusted input voltage is output to an external load device connected to the output terminal of the underwater wireless power transmission device.