Laser current control method, apparatus, and storage medium based on feedback linearization

Abstract

The application relates to a laser current control method and device based on feedback linearization, and a storage medium, the method comprising the following steps: S1, modeling a target laser based on behavior characteristic data obtained through testing, to obtain a laser behavior characteristic model considering temperature influence; and S2, performing feedback linearization control considering nonlinear characteristics for the target laser.Compared with the prior art, the application can effectively improve the control performance of the nonlinear system by introducing a proper feedback mechanism to offset the nonlinearity of the system, linearizing the laser driving system (including a semiconductor laser) by using the feedback linearization method, enabling the laser injection current to quickly and accurately follow the given current, i.e., the laser output optical power can accurately follow the given optical power, and the feedback linearization control can significantly improve the dynamic following performance and the steady-state error performance of the laser wireless energy transmission system.

Description

Technical Field

[0001] This invention relates to the field of laser control technology, and in particular to a laser current control method, device, and storage medium based on feedback linearization. Background Technology

[0002] Laser wireless power transfer technology is a promising long-range wireless power transfer method. It utilizes a laser to convert electrical energy into laser light, which is then transmitted to the target device in free space via an energy transfer medium. A photovoltaic array then converts the laser light back into electrical energy, enabling long-range, wireless power transfer from the source to the target device. This technology boasts advantages such as high transmission power, long transmission distance, no electromagnetic interference, small transceiver size, and high power density. Although research and improvement are ongoing in high-power, high-efficiency, and long-distance transmission, this technology holds the promise of improving the efficiency and reliability of energy transfer in the future, bringing greater convenience and innovation to various fields.

[0003] Semiconductor lasers (laser diodes) are considered an excellent choice for the laser component in wireless laser power transmission systems due to their high efficiency, compact structure, flexible control, and low cost. Semiconductor lasers achieve population inversion by injecting current to excite the semiconductor material. Through the design of an optical resonant cavity, they can ultimately emit laser light. As a current-injection device, it has high requirements for the quality of the input current; inappropriate current can lead to performance degradation or even damage to the device.

[0004] Considering the power control requirements of laser wireless power transmission systems, semiconductor lasers need to adjust their output laser power according to the power demand of the target device; that is, the semiconductor laser driver power supply must effectively control the laser injection current. The dynamic tracking and steady-state error performance of the laser current directly corresponds to the dynamic tracking and steady-state error performance of the transmitted power in the laser wireless power transmission system. Therefore, to ensure the efficient, safe, and reliable operation of semiconductor lasers, research is needed on high-performance current control methods for semiconductor laser driver power supplies, requiring the design of suitable semiconductor laser driver power supplies and corresponding current control methods.

[0005] Linear power supplies achieve linear control of the laser current by sampling the output current and controlling the linear adjustment unit. They offer advantages such as good stability, low output ripple, no high-frequency noise, and rapid response to load changes. However, the linear adjustment unit operates in the variable resistance region (non-saturation region), converting excess energy into heat, resulting in significant heat generation. This leads to relatively low efficiency and limits the application of linear power supplies in driving systems for medium- and high-power semiconductor lasers (above 100 watts).

[0006] Compared to linear power supplies, switching power supplies have advantages such as high efficiency, compact structure, wide voltage regulation range, and good regulation performance, as the power electronic devices in them operate in the on and off states. Therefore, they are more suitable as driving power supplies for medium-power and high-power semiconductor lasers.

[0007] Semiconductor lasers exhibit strong nonlinear characteristics, which impacts the design of their current controllers. Currently, PI control (classical linear control) is commonly used to control the laser current. However, due to the strong nonlinearity of semiconductor lasers, controller parameters obtained for a specific operating point have limited adaptability to other operating points, affecting dynamic adjustment characteristics and steady-state performance. The proposed "Design of a DC-DC Constant Current Source for a Nonlinear LED Load" employs a parameter-adjustable PID control method, manually tuning the PID control parameters at several operating points and making localized, small-range linear corrections to the PID parameters based on real-time deviations. While the method is simple in principle, it requires tuning the PID parameters at multiple operating points to achieve full operating range coverage, failing to fundamentally solve the nonlinearity problem. It merely divides the nonlinear system into multiple regions for approximate linearization.

[0008] In summary, the main problem with semiconductor laser current control in current laser wireless power transmission systems lies in the failure to consider the strong nonlinear characteristics of the laser (threshold characteristics, voltage-current nonlinearity, and temperature characteristics). When designing the controller and tuning parameters, using classical linear controllers (such as PI control) leads to a decrease in the dynamic and steady-state performance of the laser current control. Currently, there is a lack of laser current control methods to overcome or partially overcome the aforementioned problems. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art by providing a laser current control method, device, and storage medium based on feedback linearization. By introducing nonlinear feedback, the complex nonlinear problem is transformed into a linear problem, thereby improving control performance.

[0010] The objective of this invention can be achieved through the following technical solutions:

[0011] One aspect of the present invention provides a laser current control method based on feedback linearization, comprising the following steps:

[0012] S1, Model the target laser based on the behavioral characteristic data obtained from the test, and obtain a laser behavioral characteristic model that takes into account the effect of temperature;

[0013] S2, For the target laser, feedback linearization control taking into account nonlinear characteristics is performed.

[0014] As a preferred technical solution, step S1 includes the following steps:

[0015] S1.1, Obtain behavioral characteristic data of the target laser through testing;

[0016] S1.2, Characteristic curves are divided based on threshold current points;

[0017] S1.3, Perform polynomial fitting on the characteristic curve;

[0018] S1.4, interpolate the polynomial fitting results at different temperatures to obtain a laser behavior characteristic model that takes into account the temperature effect.

[0019] As a preferred technical solution, the characteristic curves include the input-output characteristic curve and the input volt-ampere characteristic curve.

[0020] As a preferred technical solution, step S2 includes the following steps:

[0021] S2.1, Construct the state equations for the target laser driving system;

[0022] S2.2, the state equation is converted into a single-input-single-output affine nonlinear system form;

[0023] S2.3, Verification of precise feedback linearization conditions;

[0024] S2.4, the nonlinear system is converted into an equivalent linear system through nonlinear coordinate transformation;

[0025] S2.5, Construct a controller based on the equivalent linear system and perform feedback linearization control on the target laser.

[0026] As a preferred technical solution, the state equation of the target laser driving system is:

[0027]

[0028] Among them, i L u C These represent the inductor current and the capacitor voltage, u in The input voltage of the converter is given by L and C, respectively, where L is the inductance and C is the capacitance of the converter. LD u LD These represent the current and voltage of the target laser, respectively; d is the control duty cycle; i LD =f LD (u LD , T) is a nonlinear term used to characterize the nonlinear characteristics of the input voltage and current of a semiconductor laser.

[0029] As a preferred technical solution, the single-input-single-output affine nonlinear system takes the following form:

[0030]

[0031]

[0032]

[0033] Where x1 and x2 are the first and second state variables, respectively, with the first state variable representing the inductor current and the second state variable representing the capacitor voltage. u represents the system's input variable, i.e., the duty cycle, and f, g, and h are domains. The nonlinear functions are sufficiently smooth, and the vector functions f and g are vector fields in the field D.

[0034] As a preferred technical solution, after the verification of the precise feedback linearization condition is passed, the equivalent linear system is obtained as follows:

[0035]

[0036]

[0037]

[0038] Where v is the control quantity of the equivalent linear system.

[0039] As a preferred technical solution, the behavioral characteristic data includes temperature, voltage, current, and output optical power.

[0040] In another aspect, an electronic device is provided, comprising: one or more processors and a memory, wherein the memory stores one or more programs, the one or more programs including instructions for performing the above-described feedback linearization-based laser current control method.

[0041] In another aspect, the present invention provides a computer-readable storage medium including one or more programs executable by one or more processors of an electronic device, the one or more programs including instructions for performing the above-described feedback linearization-based laser current control method.

[0042] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0043] (1) Improved control performance: This method controls the current of semiconductor laser based on feedback linearization. This method can fully take into account the nonlinear characteristics of semiconductor laser and realize the accurate linearization of equivalent system by using nonlinear coordinate transformation. This method can effectively improve the dynamic tracking performance of laser current and improve the power regulation performance of laser wireless energy transmission system. It has the characteristics of fast tracking and small overshoot.

[0044] (2) Facilitates the analysis of characteristics: The mathematical model established based on the test data of semiconductor laser behavior characteristics facilitates the analysis of the electro-optical-thermal characteristics of semiconductor lasers and enables intuitive analysis of the nonlinear characteristics of lasers. Attached Figure Description

[0045] Figure 1 This is a flowchart of the laser current control method based on feedback linearization in the embodiment;

[0046] Figure 2 This is a schematic diagram of the semiconductor laser driving system in the embodiment;

[0047] Figure 3 The voltage-current characteristics and current-optical power characteristics of a semiconductor laser in the embodiment are shown.

[0048] Figure 4 This is a schematic diagram comparing the voltage-current characteristics of a semiconductor laser model with measured data in the embodiment.

[0049] Figure 5 This is a schematic diagram comparing the current-optical power characteristics of a semiconductor laser model with measured data in the embodiment.

[0050] Figure 6 This is a block diagram illustrating the system feedback linearization control principle in the embodiment.

[0051] Figure 7 This is a schematic diagram showing the simulation results and current-following characteristics of the semiconductor laser in the embodiment. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0053] Example 1

[0054] Existing laser current control methods have the following drawbacks:

[0055] (1) The linear power supply system of semiconductor laser has problems such as high loss, serious heat generation and low efficiency, and is not suitable for high-power laser wireless energy transmission system.

[0056] (2) The semiconductor laser switching power supply system using the classic PI controller fails to fully consider the strong nonlinear characteristics (threshold characteristics, voltage-current nonlinearity, temperature characteristics) of the semiconductor laser, resulting in relatively weak current control performance. When the controller parameters set for a certain operating point are applied to other operating points, their dynamic and static performance will be reduced.

[0057] (3) The parameter self-adjusting current control method is equivalent to dividing the nonlinear system into multiple small linear intervals to improve the system's control performance. The specific control effect is related to the number of set operating points. However, this piecewise linear approximation method differs from the precise feedback linearization method and fails to completely solve the problems caused by the strong nonlinearity of semiconductor lasers.

[0058] To address the problems existing in the prior art, this embodiment provides a laser current control method based on feedback linearization. It studies the mathematical model characterization of the nonlinear characteristics of semiconductor lasers, introduces an appropriate feedback mechanism to counteract the nonlinearity of the system, and uses a feedback linearization method to linearize the laser driving system (including the semiconductor laser). This effectively improves the control performance of the nonlinear system, enabling the laser injection current to quickly and accurately follow the given current, i.e., the laser output optical power to accurately follow the given optical power. Feedback linearization control can significantly improve the dynamic tracking performance and steady-state error performance of the laser wireless energy transmission system.

[0059] See Figure 1 This method mainly consists of two parts: the first part is accurate modeling of semiconductor lasers based on behavioral characteristic data (mathematical model representation of nonlinear characteristics), and the second part is feedback linearization control of the semiconductor laser driving system. The two parts will be explained separately below.

[0060] S1.1 Test the temperature, voltage, current, and output optical power of the semiconductor laser.

[0061] The semiconductor laser input is connected to a laser power supply, and the output laser light shines onto the laser power meter probe to measure the laser's output power. The output power is read from the laser power meter. Voltage, current, and temperature sensors measure and read the laser's input voltage, input current, and operating temperature. The data are grouped according to the operating temperature; data in the same group correspond to the same temperature. The curve formed by the data in the same group is the laser characteristic curve at a specific temperature.

[0062] S1.2 Based on threshold current point (u th i th The characteristic curves are divided to obtain the input-output characteristic curves and input volt-ampere characteristic curves of the semiconductor laser under different operating conditions.

[0063] Because lasers possess threshold characteristics, the two sides of the threshold current correspond to different operating states of the laser, emitting weaker, broader-spectrum fluorescence and stronger, narrower-spectrum, better-coherent laser light, respectively. Therefore, for each laser characteristic curve, the threshold current operating point (u) is used as the reference point. th i th The characteristic curve can be divided into two parts. The first part is located to the left of the threshold operating point and has the following characteristics: u LD ≤u th i LD ≤i th P LD ≈0; The second part is located to the right of the threshold operating point and has the following characteristics u LD >u th i LD >i th P LD >0; these two parts exhibit different input-output characteristics and input current-voltage characteristics.

[0064] S1.3 Performs curve fitting (polynomial fitting) on ​​the behavior characteristics of semiconductor lasers and provides the polynomial fitting results of the corresponding characteristic curves.

[0065] The laser characteristic curves have been segmented according to the threshold point. At this point, for a specific temperature, there are a total of four characteristic curves: the input current-output optical power characteristic curve (i...). LD ≤i th ), Input current-output optical power characteristic curve (i LD >i th Input voltage-current characteristic curve (u) LD ≤u th Input voltage-current characteristic curve (u) LD >u th Curve fitting is performed on each characteristic curve.

[0066] Furthermore, based on the curve shapes of the input-output characteristics and input current-voltage characteristics of semiconductor lasers, linear fitting is sufficient to accurately describe the characteristics of the input current-output optical power characteristic curve; however, nonlinear fitting is often required to accurately describe the characteristics of the input current-voltage characteristic curve.

[0067] Furthermore, the first part of the input current-output optical power characteristic curve (less than or equal to the threshold current) can be approximately expressed as P LD =0(i LD ≤i th );

[0068] Furthermore, the second part of the input current-output optical power characteristic curve (above the threshold current), for semiconductor lasers, shows that when the pump current exceeds the threshold current, the power increases linearly with increasing current. Approximately, this can be expressed as P... LD =K*(i LD -i th ),(i LD >i th ), where K is a constant, with units of watts per ampere (W / A), and its physical meaning is slope efficiency, which is a key physical quantity for measuring the output characteristics of a laser;

[0069] Furthermore, the input voltage-current characteristic curve can be accurately described by nonlinear fitting, and can be expressed as i LD =f LD (u LD Its characteristics can be accurately described using polynomial fitting. Taking a second-order polynomial as an example, it can be represented as i LD =a*u LD *u LD +b*u LD +c;

[0070] Furthermore, for some semiconductor lasers, higher-order polynomials are required to achieve better fitting results;

[0071] Optionally, for some semiconductor lasers, the corresponding fitting parameters need to be solved separately on the left and right sides of the threshold current to obtain a better fitting effect;

[0072] Alternatively, for some semiconductor lasers, the same set of fitting parameters can achieve a good fitting effect on both the left and right sides of the threshold current.

[0073] Optionally, for some semiconductor lasers, water cooling (with a laser chiller) or other methods can be used to control the operating temperature of the semiconductor laser to near a preset temperature. Under different load conditions, the operating temperature of the semiconductor laser is similar. In this case, the mathematical model of the semiconductor laser that can fully reflect the characteristics of the laser can be obtained through step S1.3, and there is no need to carry out the temperature interpolation related operation in S1.4.

[0074] Completing this step yields a simplified mathematical model that fully reflects the nonlinear characteristics of the semiconductor laser. The method is driven by test data and ultimately provides an electrical port model and an electro-optical conversion model for the semiconductor laser, which can be expressed in mathematical terms.

[0075] S1.4 For semiconductor lasers that may operate at multiple temperatures, interpolating the parameter values ​​of the fitted models obtained at different temperatures can yield a laser behavior characteristic model that takes into account the temperature effect.

[0076] Based on step S1.3, if the semiconductor laser may operate at different temperatures, the model needs to be modified to take into account the influence of the laser's operating temperature.

[0077] Furthermore, the first part of the input current-output optical power characteristic curve (less than or equal to the threshold current) can still be approximately expressed as P. LD =0(i LD ≤i th );

[0078] Furthermore, in the second part of the input current-output optical power characteristic curve (above the threshold current), for semiconductor lasers, when the pump current exceeds the threshold current, the power increases linearly with increasing current. Under normal operating conditions, the power decreases with increasing temperature, which can be approximated as P LD =K(T)*(i LD -i th ),(i LD >i th K(T) is a function of temperature as the independent variable, with the unit being watts per ampere (W / A). Its physical meaning is slope efficiency, which is a key physical quantity for measuring the output characteristics of a laser and can reflect the temperature characteristics of slope efficiency.

[0079] Furthermore, the input voltage-current characteristic curve can be accurately described by nonlinear fitting, and can be expressed as i LD =f LD (u LD The characteristics of a polynomial (T) can be accurately described using polynomial fitting. For example, a second-order polynomial can be represented as i LD =a(T)*u LD *u LD +b(T)*u LD +c(T) can reflect the effect of temperature on the voltage-current characteristics.

[0080] Furthermore, K(T), a(T), and b(T) can be solved using interpolation, taking into account different operating temperatures (T1, T2…T). n By fitting the model parameters under a finite number of points, an approximate value is estimated for the entire operating temperature range.

[0081] S2.1 Establish the state equations for the laser drive system (including power supply and laser).

[0082] The mathematical model of a semiconductor laser can be obtained through S1, which can be equivalent to a (voltage-controlled) controlled current source.

[0083]

[0084] The semiconductor laser, acting as a load for the laser driver power supply, is connected to the output terminal of the driver power supply, such as... Figure 2 As shown;

[0085] Based on Kirchhoff's voltage and current theorems, by taking inductor current and capacitor voltage as state variables, the state-space expression of the system can be established.

[0086] Furthermore, with Figure 2 Taking the BUCK converter shown as an example, the system's state equation is as follows:

[0087]

[0088] Among them, i L ,u C These represent the inductor current and the capacitor voltage, u in Let L be the input voltage of the converter, and C be the inductance and capacitance of the converter, respectively. LD ,u LD denoted as the laser current and voltage, respectively, and d is the control duty cycle;

[0089] Where i LD =f LD (u LD The term T is a nonlinear term that characterizes the nonlinear characteristics of the input voltage and current of the semiconductor laser. Therefore, the system state equation obtained by modeling using the state-space averaging method is nonlinear. If a traditional linear controller is used to control such a nonlinear system, its dynamic and steady-state performance will be affected.

[0090] S2.2 Select the state variables and represent them in the standard form of a single-input single-output affine nonlinear system.

[0091] The state variables are the inductor current and the capacitor voltage. The system state equations obtained in the previous steps can be transformed into the standard form of a single-input single-output affine nonlinear system.

[0092]

[0093] in,

[0094]

[0095]

[0096] x1 and x2 are state variable 1 (inductor current) and state variable 2 (capacitor voltage), respectively, and u represents the system input variable (duty cycle).

[0097] S2.3 Verification of precise feedback linearization conditions.

[0098] Consider a single-input single-output (SISO) system corresponding to formulas (3)-(5), where f, g, h are domains. The derivative of a sufficiently smooth nonlinear function, where vector functions f and g are vector fields in the field D, is... The definition is

[0099]

[0100] Where the Lie derivative is defined as

[0101]

[0102] The two conditions for precise feedback linearization are as follows:

[0103] Condition 1, matrix For all X in the vicinity of X0, its rank remains unchanged and is equal to n.

[0104] Condition 2, the geometry of the vector field The pairing occurs at X0.

[0105] If the relative order of the system is λ = n, then in a neighborhood N of X0, there exists a mapping T(x) in equation (8) that is a differential isomorphic over N.

[0106]

[0107] S2.4 Perform nonlinear coordinate transformation to convert the nonlinear system into an equivalent linear system.

[0108] If the feedback linearization condition in S2.3 is satisfied, the following nonlinear coordinate transformation is performed.

[0109]

[0110] The system can then be transformed into an equivalent linear system (Brunowski canonical form) as follows.

[0111]

[0112] v is the control quantity of the new system. According to the feedback exact linearization theory, the relationship between the original system control quantity u (here, duty cycle d) and the new control quantity v can be obtained as follows:

[0113]

[0114] S2.5 focuses on controller design for equivalent linear systems.

[0115] For an equivalent linear system ξ, a feedback controller can be designed to control the system based on the typical requirements of the dynamic performance of the closed-loop system.

[0116] The above completes the entire process of high-performance current control of semiconductor lasers based on feedback linearization control. It mainly includes two parts: the first part is the mathematical model characterization of the nonlinear characteristics of the semiconductor laser, and the second part is the feedback linearization control that takes into account the nonlinear characteristics of the semiconductor laser.

[0117] The main features of this method are: establishing an external characteristic model of the semiconductor laser to reflect its nonlinear characteristics; introducing nonlinear feedback through appropriate nonlinear coordinate transformation to accurately convert the strongly nonlinear laser driving system into an equivalent linear system; thus transforming the complex nonlinear problem into a linear problem. Unlike other local linearization approximation methods, feedback linearization control is effective for the entire working range.

[0118] The following is a practical example to illustrate this.

[0119] (1) The measured operating characteristics of a semiconductor laser are as follows: Figure 3 As shown in (a) and (b), the laser is kept at a working temperature of approximately 25°C by a laser chiller. Therefore, in this embodiment, the effect of temperature on the laser can be ignored.

[0120] (2) The threshold current i of the semiconductor laser th =1.2A, corresponding to the voltage u at the threshold current. th =39.2V; In addition, when the voltage is less than a certain value (u ith When the voltage is 36.5V, the laser injection current is approximately zero. For this semiconductor laser, curve fitting (polynomial fitting) yields the following mathematical model:

[0121]

[0122]

[0123] The curve fitting results are A = 20.4, B = 24.5, C = 0.127, D = 0.0872, i th =1.2A, u th =39.2V, u ith =36.5V;

[0124] For this semiconductor laser, at the threshold current operating point (u th i thOn both sides of the voltage-current characteristic, using the same set of parameters can achieve a good fitting effect, therefore there is no need to (u) th i th Different fitting models are used on both sides of the above polynomial fitting. The goodness of fit (R-square criterion, RMSE) of the above polynomial fitting are [0.9996, 0.9856] for current-optical power fitting and [0.9975, 0.1420] for voltage-current fitting, respectively. The R-square coefficient of determination is close to 1, and the root mean square error of RMSE is relatively small, so the model can be considered to have high fitting accuracy.

[0125] Comparison of amplified semiconductor laser model and measured data, for example Figure 4 , Figure 5 As shown in the figure, the semiconductor laser model established based on the test data has high accuracy and can simulate the external characteristics of the semiconductor laser through curve fitting and other methods, as shown in formulas (12) and (13), which are the input-output characteristics and voltage-current characteristics of the semiconductor laser model, respectively.

[0126] Therefore, for Figure 2 The state equation of the semiconductor laser driving system shown can be written as follows:

[0127]

[0128]

[0129] It can be seen from formula (15) that the system is a nonlinear system at this time, and the main nonlinear term is the semiconductor laser term.

[0130] Due to u c ≤u ith When the laser voltage is low, the laser current is near 0. The state-space average model of the laser drive system is linear. The actual laser only operates in this operating range when the output light is turned off.

[0131] By selecting the state variables and representing them in the standard form of a single-input, single-output affine nonlinear system, we can obtain:

[0132]

[0133] For u c >u ith Sometimes,

[0134]

[0135]

[0136] Where L and C represent the inductance and capacitance of the Buck converter, x1 and x2 represent the system state variables (inductor current and capacitor voltage, respectively), C and D are the fitting constants for the semiconductor laser model, and u ith u represents the characteristic parameters of the laser model. in This is the input voltage of the converter.

[0137] Simplifying f(x), we have

[0138]

[0139] in

[0140]

[0141] The following Lie derivative can be obtained for this system.

[0142]

[0143] Given that the relative order of the system is λ = n = 2, the nonlinear driving system of this semiconductor laser can be equivalently transformed into a linear system ξ.

[0144] Therefore, the block diagram of the system feedback linearization control principle is as follows: Figure 6 As shown, it includes a linear controller, a feedback control law calculation module, and a nonlinear coordinate transformation module. The target quantity z... r The error quantity e is obtained by subtracting the output z of the equivalent linear system from the semiconductor laser drive system. This error quantity e is then used as the input to the linear controller to obtain the control quantity v of the equivalent linear system. The control quantity v of the equivalent linear system, along with reference quantities α(x) and β(x), are used as inputs to the feedback control law calculation module to obtain the original nonlinear system control quantity u, which is then used to control the nonlinear semiconductor laser drive system. Based on the original system control quantity u, the reference quantities α(x) and β(x) of the nonlinear coordinate transformation module, as well as the output of the equivalent linear system, are updated. Finally, using the original system control quantity u as the input to the semiconductor laser drive system, the output quantity z is updated, completing one control process.

[0145] in,

[0146]

[0147] Simulation using MATLAB / Simulink confirmed that the semiconductor laser driving circuit is as follows: Figure 2 The Buck circuit topology shown has a semiconductor laser with characteristics as follows: Figure 3 The simulated parameters for a real semiconductor laser are as follows: switching frequency 50kHz, inductance 660uH, capacitance 4700uF, and power supply voltage 100V. A PI controller and a feedback linearization controller are used to control the system. (PI controller K)p K i The values ​​are 0.01 and 350 respectively, and the feedback linearization controllers K1 and K2 are 4×10. 6 4.8×10 3 .

[0148] Figure 6 The simulation current graph of the semiconductor laser shows that the current setpoint was adjusted to 10A / 3A / 7A / 5A at 0s / 0.05s / 0.10s / 0.15s respectively. The current tracking performance of the semiconductor laser was observed. It can be seen that in the same system, the feedback linear control has a faster tracking speed, smaller overshoot, and smaller current ripple during startup than the PI control. This indicates that the feedback linear control applied to the semiconductor laser drive system has better power regulation performance than the PI control and can improve the laser control performance.

[0149] Example 2

[0150] This embodiment provides an electronic device, including: one or more processors and a memory, wherein the memory stores one or more programs, the one or more programs including instructions for executing the laser current control method based on feedback linearization as described in Embodiment 1.

[0151] Example 3

[0152] This embodiment provides a computer-readable storage medium including one or more programs executable by one or more processors of an electronic device, the one or more programs including instructions for performing a laser current control method based on feedback linearization as described in Embodiment 1.

[0153] On the one hand, the mathematical model established by this invention based on the test data of semiconductor laser behavior characteristics facilitates the analysis of the electro-optical-thermal characteristics of semiconductor lasers and enables intuitive analysis of the nonlinear characteristics of lasers; on the other hand, the state-space model of the semiconductor laser driving system and the corresponding simulation model established by this invention can more conveniently and intuitively analyze the impact of the nonlinear characteristics of semiconductor lasers on converter control.

[0154] On the other hand, controlling the current of a semiconductor laser based on feedback linearization technology can fully take into account the nonlinear characteristics of the semiconductor laser and achieve accurate linearization of the equivalent system by using nonlinear coordinate transformation. This method can effectively improve the dynamic tracking performance of the laser current and enhance the power regulation performance of the laser wireless energy transmission system, and has the characteristics of fast tracking and small overshoot.

[0155] Finally, the simulation study of semiconductor laser current control using this invention can provide theoretical support for improving the dynamic characteristics of laser current, guide the design of current controllers, improve the power regulation performance of laser energy transmission systems, save design time, and reduce development costs.

[0156] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A laser current control method based on feedback linearization, characterized in that, Includes the following steps: S1, Model the target laser based on the behavioral characteristic data obtained from the test, and obtain a laser behavioral characteristic model that takes into account the effect of temperature; S2, For the target laser, feedback linearization control taking into account nonlinear characteristics is performed; S1 includes the following steps: S1.1, Obtain behavioral characteristic data of the target laser through testing; S1.2, Characteristic curves are divided based on threshold current points; S1.3, Perform polynomial fitting on the characteristic curve; S1.4, interpolate the polynomial fitting results at different temperatures to obtain a laser behavior characteristic model that takes into account the temperature effect; S2 includes the following steps: S2.1, Construct the state equations for the target laser driving system; S2.2, the state equation is converted into a single-input-single-output affine nonlinear system form; S2.3, Verification of precise feedback linearization conditions; S2.4, the nonlinear system is converted into an equivalent linear system through nonlinear coordinate transformation; S2.5, Construct a controller based on the equivalent linear system and perform feedback linearization control on the target laser.

2. The laser current control method based on feedback linearization according to claim 1, characterized in that, The characteristic curves include the input-output characteristic curve and the input volt-ampere characteristic curve.

3. The laser current control method based on feedback linearization according to claim 1, characterized in that, The state equation of the target laser driving system is: in, i L , u C These are the inductor current and the capacitor voltage, respectively. u in The input voltage of the converter, L , C These are the converter inductor and capacitor, respectively. i LD , u LD These represent the current and voltage of the target laser, respectively. d To control the duty cycle, This is a nonlinear term used to characterize the nonlinear characteristics of the input voltage and current of a semiconductor laser.

4. The laser current control method based on feedback linearization according to claim 3, characterized in that, A single-input, single-output affine nonlinear system has the following form: in, x 1. x 2 represents the first state variable and the second state variable, respectively, where the first state variable is the inductor current and the second state variable is the capacitor voltage. u This represents the system's input variable, namely the duty cycle. f , g , h It is a domain A sufficiently smooth nonlinear function, and a vector function. f and g It is a domain D Vector field in.

5. A laser current control method based on feedback linearization according to claim 4, characterized in that, After the exact feedback linearization condition verification is passed, the equivalent linear system is obtained as follows: in, v It represents the control quantity for an equivalent linear system.

6. The laser current control method based on feedback linearization according to claim 1, characterized in that, The behavioral characteristic data includes temperature, voltage, current, and output optical power.

7. An electronic device, characterized in that, include: One or more processors and a memory, wherein the memory stores one or more programs, the one or more programs including instructions for executing the laser current control method based on feedback linearization as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, Includes one or more programs executable by one or more processors of an electronic device, the one or more programs including instructions for performing the laser current control method based on feedback linearization as described in any one of claims 1-6.

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